WO2012121089A1 - Display element and electric device using same - Google Patents

Abstract

A display element (10) is equipped with: an upper substrate (first substrate) (2); a lower substrate (second substrate) (3); and a polar liquid (16) sealed so as to be able to move to the side of an effective display region (P1) or the side of a non-effective display region (P2) inside a display space (S) formed between the upper substrate (2) and the lower substrate (3). The display element (10) is provided with: a difference information acquisition unit (54) for obtaining the difference of the gradation values of continuous two frames (F1, F2) for each pixel region (P) as difference information; and a scan time determination unit (56) for determining scan time in a scan operation on the basis of the difference information from the difference information acquisition unit (54). A display control unit (50) allows the scan operation to be performed according to the scan time by using the difference information from the difference information acquisition unit (54) and the scan time from the scan time determination unit (56).

Description

Display element and electric device using the same

The present invention relates to a display element that displays information such as images and characters by moving a polar liquid, and an electrical device using the display element.

In recent years, as a display element represented by an electrowetting type display element, a display element has been developed and put into practical use by utilizing the phenomenon of polar liquid movement by an external electric field.

Specifically, in the conventional display element as described above, for example, as described in Patent Document 1 below, a display space is formed between the first and second substrates, and ribs (partitions) are formed. The interior of the display space is partitioned according to a plurality of pixel regions by a wall. Further, in this conventional display element, in each of the pixel regions, a conductive liquid (polar liquid) is sealed, and a signal electrode, a scan electrode and a reference electrode (reference electrode) provided in parallel to each other are provided. It was provided to cross. In this conventional display element, in each pixel region, by appropriately applying a voltage to the signal electrode, the scan electrode, and the reference electrode, the conductive liquid is moved to the scan electrode side or the reference electrode side to display. The display color on the face side was changed.

International Publication No. 2010/016304 Pamphlet

By the way, in the conventional display element as described above, by adjusting the voltage application time to the signal electrode, the amount of movement of the conductive liquid (polar liquid) is changed to change the display color on the display surface side to a halftone. In other words, so-called gradation display is performed.

However, the conventional display element as described above sometimes has a problem that it is difficult to change the display color, that is, to speed up the display operation. In particular, in the conventional display element, when the gradation display is performed, there is a possibility that the display operation cannot be performed at a high speed depending on the previous display color (that is, the position of the conductive liquid).

In view of the above problems, an object of the present invention is to provide a display element capable of performing a display operation at high speed even when gradation display is performed, and an electric device using the display element.

In order to achieve the above object, the display element according to the present invention is configured such that a predetermined display space is formed between the first substrate provided on the display surface side and the first substrate. , The second substrate provided on the non-display surface side of the first substrate, the effective display area and the non-effective display area set for the display space, and the effective inside the display space. A display element configured to change a display color on the display surface side by moving the polar liquid, the polar liquid being movably sealed on the display area side or the ineffective display area side There,
A plurality of signal electrodes disposed in the display space so as to be in contact with the polar liquid and provided along a predetermined arrangement direction;
Provided on one side of the first and second substrates in a state of being electrically insulated from the polar liquid so as to be installed on one side of the effective display area side and the non-effective display area side. And a plurality of scanning electrodes provided to intersect with the plurality of signal electrodes,
A plurality of pixel regions provided in a unit of intersection between the signal electrode and the scanning electrode;
A display control unit that controls each drive of the signal electrode and the scanning electrode so that a scanning operation along a predetermined scanning direction is performed based on an image input signal from the outside;
Connected to the plurality of signal electrodes and the display control unit, and in accordance with an instruction signal from the display control unit, for each of the plurality of signal electrodes, a predetermined value corresponding to information displayed on the display surface side A signal voltage application unit for applying a signal voltage within a voltage range;
Connected to the plurality of scan electrodes and the display control unit, and allows the polar liquid to move inside the display space in accordance with the signal voltage with respect to the plurality of scan electrodes. A scanning voltage applying unit that applies one of a selection voltage and a non-selection voltage that prevents the polar liquid from moving inside the display space;
A difference information acquisition unit that obtains a difference between gradation values in two consecutive frames for each pixel area using an image input signal from the outside, and acquires the difference information;
Based on the difference information from the difference information acquisition unit, a scanning time determination unit for determining a scanning time in the scanning operation is provided,
The display control unit generates each instruction signal to the signal voltage application unit and the scanning voltage application unit using the difference information from the difference information acquisition unit and the scanning time from the scanning time determination unit, The scanning operation according to the scanning time is performed.

In the display element configured as described above, the difference information acquisition unit obtains the difference between the gradation values in two consecutive frames for each pixel area using the image input signal from the outside, and acquires the difference information as difference information. . In addition, the scanning time determination unit determines the scanning time in the scanning operation based on the difference information from the difference information acquisition unit. Further, the display control unit generates each instruction signal to the signal voltage application unit and the scanning voltage application unit using the difference information from the difference information acquisition unit and the scanning time from the scanning time determination unit, and at the scanning time, A corresponding scanning operation is performed. Thus, unlike the conventional example, it is possible to configure a display element that can perform a display operation at high speed even when performing gradation display.

Further, in the display element, the display control unit is provided with a scanning operation determining unit that determines whether or not to perform a scanning operation based on a scanning time from the scanning time determining unit,
The signal voltage applying unit and the scanning voltage applying unit preferably apply voltage to the signal electrode and the scanning electrode, respectively, according to a determination result of the scanning operation determining unit.

In this case, even when gradation display is performed, the display operation can be performed at higher speed.

Further, in the display element, the first liquid electrode is electrically insulated from the polar liquid and the scan electrode so as to be installed on the other side of the effective display area side and the ineffective display area side. A plurality of reference electrodes provided on one side of the first and second substrates and provided to intersect with the plurality of signal electrodes;
The polar liquid is connected to the plurality of reference electrodes and the display control unit and allows the polar liquid to move in the display space according to the signal voltage with respect to the plurality of reference electrodes. A reference voltage applying unit that applies one voltage of a selection voltage and a non-selection voltage that prevents the polar liquid from moving inside the display space;
The display control unit performs drive control of the signal electrode, the scan electrode, and the reference electrode so that a scanning operation along a predetermined scanning direction is performed based on an external image input signal. ,
The display control unit uses the difference information from the difference information acquisition unit and the scanning time from the scanning time determination unit, to each of the signal voltage application unit, the scanning voltage application unit, and the reference voltage application unit It is preferable to generate an instruction signal and perform a scanning operation according to the scanning time.

In this case, a matrix drive type display element capable of performing a display operation at high speed even when gradation display is performed can be configured without providing a switching element for each pixel region.

Further, in the display element, the display control unit is provided with a scanning operation determining unit that determines whether or not to perform a scanning operation based on a scanning time from the scanning time determining unit,
The signal voltage application unit, the scan voltage application unit, and the reference voltage application unit apply voltages to the signal electrode, the scan electrode, and the reference electrode, respectively, according to the determination result of the scanning operation determination unit. It is preferable to carry out.

In this case, even when gradation display is performed, the display operation can be performed at higher speed.

In the display element, it is preferable that a dielectric layer is laminated on the surfaces of the reference electrode and the scanning electrode.

In this case, the electric field applied to the polar liquid by the dielectric layer can be reliably increased, and the moving speed of the polar liquid can be improved more easily.

Further, in the display element, the scanning time determination unit determines the scanning time in the scanning operation according to the maximum absolute value of the difference between the gradation values included in the difference information from the difference information acquisition unit. It is preferable to determine.

In this case, the scanning time in the scanning operation can be shortened in accordance with display information in two consecutive frames, and the display operation can be further speeded up even when gradation display is performed. it can.

In the display element, the display control unit includes a value of 0 in a difference between gradation values in two consecutive frames in a plurality of pixel regions that are symmetrical with respect to one scanning operation. Is determined, an intermediate voltage in the middle of the predetermined voltage range is preferably applied to a signal electrode corresponding to a pixel region having a difference value of zero.

In this case, the polar liquid can be reliably stopped in the pixel region where the difference value is 0, and the display quality of the display element can be reliably prevented from being deteriorated.

In addition, the display element preferably includes a storage medium that holds data of an image input signal of the last frame in the previous display operation.

In this case, the operation of the display element can be performed smoothly.

Further, in the display element, it is preferable that a memory capable of storing image input signal data for at least one frame is used for the difference information acquisition unit.

In this case, accurate difference information can be obtained reliably and easily.

Further, in the display element, it is preferable that the difference information acquisition unit is provided in the display control unit.

In this case, unlike the case where the difference information acquisition unit is provided in the signal voltage application unit, a general-purpose voltage application unit (driver) can be used for the signal voltage application unit. Further, it is possible to easily output an instruction signal from the display control unit to the signal voltage application unit or the like.

In the display element, it is preferable that a rib for separating the inside of the display space is provided on at least one side of the first and second substrates according to the plurality of pixel regions.

In this case, it is possible to easily prevent the polar liquid from being coalesced between the adjacent pixel regions by the rib.

In the display element, the plurality of pixel regions may be provided in accordance with a plurality of colors capable of full color display on the display surface side.

In this case, a color image can be displayed by appropriately moving the corresponding polar liquid in each of the plurality of pixel regions.

In the display element, it is preferable that an insulating fluid that does not mix with the polar liquid is sealed in the display space so as to be movable in the display space.

In this case, it is possible to easily increase the moving speed of the polar liquid.

In the display element, the ineffective display area is set by a light shielding film provided on one side of the first and second substrates,
The effective display area may be set by an opening formed in the light shielding film.

In this case, it is possible to appropriately and reliably set the effective display area and the non-effective display area for the display space.

The electrical device of the present invention is an electrical device including a display unit that displays information including characters and images,
Any one of the display elements described above is used for the display portion.

In the electrical equipment configured as described above, a display element capable of performing a display operation at high speed even when performing gradation display is used for the display section. Therefore, a display section capable of changing display information at high speed It is possible to easily configure a high-performance electric device provided with

According to the present invention, it is possible to provide a display element capable of performing a display operation at high speed even when gradation display is performed, and an electric device using the display element.

FIG. 1 is a plan view for explaining a display element and an image display apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a specific configuration of the display control unit shown in FIG. FIG. 3 is a block diagram showing a specific configuration of the signal driver shown in FIG. 4 is a block diagram showing a specific configuration of the reference driver shown in FIG. FIG. 5 is a block diagram showing a specific configuration of the scan driver shown in FIG. FIG. 6 is an enlarged plan view showing a main configuration of the upper substrate side shown in FIG. 1 when viewed from the display surface side. FIG. 7 is an enlarged plan view showing the main configuration of the lower substrate side shown in FIG. 1 when viewed from the non-display surface side. FIG. 8A is an enlarged plan view showing a main part configuration in one pixel region of the display element, and FIG. 8B is a sectional view taken along line VIIIb-VIIIb in FIG. 8A. FIG. 9A and FIG. 9B are cross-sectional views showing the main configuration of the display element shown in FIG. 1 during non-CF color display and CF color display, respectively. FIG. 10 is a diagram for explaining an operation example of the image display device. FIG. 11 is a diagram for explaining specific operations of the signal driver, the reference driver, and the scan driver shown in FIG. 1 in two consecutive frames, and FIG. 11A and FIG. FIG. 11C is a diagram showing a specific display image of two consecutive frames, and FIG. 11C is a diagram showing a difference image of the two frames. FIG. 12A to FIG. 12D are diagrams for explaining a specific voltage application operation of the signal driver. FIGS. 13A to 13B are diagrams for explaining another specific voltage application operation of the signal driver. FIG. 14 is a block diagram showing a specific configuration of the display control unit of the display element according to the second embodiment of the present invention. FIGS. 15A to 15D are diagrams for explaining a specific voltage application operation of the signal driver of the display element according to the second embodiment. FIG. 16 is a plan view for explaining a display element and an image display apparatus according to the third embodiment of the present invention. FIG. 17 is a block diagram showing a specific configuration of the display control unit shown in FIG. FIG. 18 is a block diagram showing a specific configuration of the signal driver shown in FIG. FIG. 19 is a plan view for explaining a display element and an image display apparatus according to the fourth embodiment of the present invention. FIG. 20 is a block diagram showing a specific configuration of the display control unit shown in FIG. FIG. 21 is a block diagram showing a specific configuration of the signal driver shown in FIG. 22 is a block diagram showing a specific configuration of the reference driver shown in FIG. FIG. 23 is a block diagram showing a specific configuration of the scan driver shown in FIG. FIG. 24 is a diagram illustrating specific operations of the signal driver, the reference driver, and the scan driver shown in FIG. 19 in two consecutive frames. FIGS. 24 (a) and 24 (b) FIG. 24C is a diagram showing a specific display image of two consecutive frames, and FIG. 24C is a diagram showing a difference image of the two frames.

Hereinafter, preferred embodiments of the display element and the electric device of the present invention will be described with reference to the drawings. In the following description, a case where the present invention is applied to an image display apparatus including a display unit capable of displaying a color image display will be described as an example. Moreover, the dimension of the structural member in each figure does not faithfully represent the actual dimension of the structural member, the dimensional ratio of each structural member, or the like.

[First Embodiment]
FIG. 1 is a plan view for explaining a display element and an image display apparatus according to a first embodiment of the present invention. In FIG. 1, the image display apparatus 1 according to the present embodiment is provided with a display unit using the display element 10 according to the present embodiment, and a rectangular display surface is configured in the display unit. Further, the display element 10 is provided with a display control unit 50, a signal driver 7, a reference driver 8, and a scanning driver 9 connected to the display control unit 50, and the display control unit 50 includes the signal driver 7, Each drive control of the reference driver 8 and the scanning driver 9 is performed. That is, an image input signal from the outside is input to the display control unit 50, and the display control unit 50 receives the signal driver 7, the reference driver 8, and the like based on the input image input signal. Each instruction signal to the scanning driver 9 is generated and output. Thereby, the display element 10 displays information including characters and images according to the image input signal.

In addition, the display element 10 includes an upper substrate 2 and a lower substrate 3 which are arranged so as to overlap each other in a direction perpendicular to the paper surface of FIG. 1, and the above-described overlapping portion of the upper substrate 2 and the lower substrate 3 causes the above-described portion. An effective display area on the display surface is formed (details will be described later).

Further, in the display element 10, a plurality of signal electrodes 4 are provided in stripes along the X direction at a predetermined interval from each other. In the display element 10, a plurality of reference electrodes 5 and a plurality of scanning electrodes 6 are provided alternately in a stripe pattern along the Y direction. The plurality of signal electrodes 4, the plurality of reference electrodes 5, and the plurality of scan electrodes 6 are provided so as to intersect with each other. In the display element 10, the signal electrodes 4 and the scan electrodes 6 are in units of intersections. A plurality of pixel areas are set.

The plurality of signal electrodes 4, the plurality of reference electrodes 5, and the plurality of scan electrodes 6 are independently of each other a high voltage (hereinafter referred to as “H voltage”) as a first voltage and a second voltage. A voltage within a predetermined voltage range between the low voltage and the low voltage (hereinafter referred to as “L voltage”) can be applied (details will be described later).

Further, in the display element 10, as described in detail later, the plurality of pixel regions are partitioned by a partition wall, and the plurality of pixel regions correspond to a plurality of colors capable of full color display on the display surface side. Are provided respectively. In the display element 10, a polar liquid described later is moved by an electrowetting phenomenon for each of a plurality of pixels (display cells) provided in a matrix, and the display color on the display surface side is changed. ing.

Further, in the plurality of signal electrodes 4, the plurality of reference electrodes 5, and the plurality of scanning electrodes 6, one end side is drawn out to the outside of the effective display area of the display surface to form terminal portions 4a, 5a, and 6a. ing.

A signal driver 7 is connected to each terminal portion 4a of the plurality of signal electrodes 4 via a wiring 7a. The signal driver 7 constitutes a signal voltage application unit. When the image display device 1 displays information including characters and images on the display surface, a plurality of each of the plurality of signal drivers 7 are in accordance with an instruction signal from the display control unit 50. A signal voltage Vd corresponding to information is applied to the signal electrode 4.

Further, a reference driver 8 is connected to each terminal portion 5a of the plurality of reference electrodes 5 via a wiring 8a. The reference driver 8 constitutes a reference voltage applying unit. When the image display device 1 displays information including characters and images on the display surface, a plurality of each of the reference drivers 8 is provided according to an instruction signal from the display control unit 50. A reference voltage Vr is applied to the reference electrode 5.

Further, a scanning driver 9 is connected to each terminal portion 6a of the plurality of scanning electrodes 6 via a wiring 9a. The scanning driver 9 constitutes a scanning voltage application unit. When the image display device 1 displays information including characters and images on the display surface, each of the plurality of scanning drivers 9 is in accordance with an instruction signal from the display control unit 50. A scanning voltage Vs is applied to the scanning electrode 6.

In the scan driver 9, a non-selection voltage that prevents the polar liquid from moving with respect to each of the plurality of scan electrodes 6, and a selection voltage that allows the polar liquid to move according to the signal voltage Vd. One of the voltages is applied as the scanning voltage Vs. The reference driver 8 is configured to operate with reference to the operation of the scanning driver 9, and the reference driver 8 prevents the polar liquid from moving with respect to each of the plurality of reference electrodes 5. One voltage of the non-selection voltage and the selection voltage that allows the polar liquid to move according to the signal voltage Vd is applied as the reference voltage Vr.

In the image display device 1, the scanning driver 9 sequentially applies the selection voltage to the scanning electrodes 6 from the left side to the right side of FIG. 1, for example, and the reference driver 8 is synchronized with the operation of the scanning driver 9. The scanning operation is performed for each line by sequentially applying a selection voltage to the reference electrodes 5 from the left side to the right side of 1 (details will be described later). In the scanning operation for each line, the signal driver 7 is configured to apply the corresponding signal voltage Vd corresponding to the information to all the signal electrodes 4 all at once.

The signal driver 7, the reference driver 8, and the scanning driver 9 include a DC power supply or an AC power supply, and supply corresponding signal voltage Vd, reference voltage Vr, and scanning voltage Vs. .

Further, the reference driver 8 is configured to switch the polarity of the reference voltage Vr every predetermined time (for example, one frame). Further, the scanning driver 9 is configured to switch each polarity of the scanning voltage Vs in response to switching of the polarity of the reference voltage Vr. Thus, since the polarities of the reference voltage Vr and the scanning voltage Vs are switched every predetermined time, the reference voltages Vr and the scanning electrode 6 are compared with the reference electrode 5 and the scanning electrode 6 when the same polarity voltage is always applied. It is possible to prevent localization of electric charges at the electrode 5 and the scanning electrode 6. Furthermore, it is possible to prevent adverse effects of display defects (afterimage phenomenon) and reliability (lifetime reduction) due to charge localization.

Next, specific configurations of the display control unit 50, the signal driver 7, the reference driver 8, and the scanning driver 9 according to the present embodiment will be described with reference to FIGS.

FIG. 2 is a block diagram showing a specific configuration of the display control unit shown in FIG. FIG. 3 is a block diagram showing a specific configuration of the signal driver shown in FIG. 4 is a block diagram showing a specific configuration of the reference driver shown in FIG. FIG. 5 is a block diagram showing a specific configuration of the scan driver shown in FIG.

As shown in FIG. 2, the display control unit 50 of the present embodiment is provided with an image processing unit 51, a frame buffer 52, and a scanning time determination unit 53. In addition, an image input signal is input to the display control unit 50 from the outside of the image display device 1, and the display control unit 50 performs a predetermined scanning direction based on the image input signal from the outside. The drive operation of the signal electrode 4, the scan electrode 6, and the reference electrode 5 is performed so that the above-described scanning operation is performed.

Further, as will be described in detail later, the display control unit 50 uses the difference information from the difference information acquisition unit described later and the scanning time from the scanning time determination unit 53 to use the signal driver 7, the scanning driver 9, and the reference driver. 8 is generated, and a scanning operation corresponding to the scanning time is performed.

Further, when the display control unit 50 determines that the difference value of the gradation value in two consecutive frames includes a value of 0 in a plurality of pixel regions that are symmetrical with one scanning operation, With respect to the signal electrode 4 corresponding to the pixel region whose difference value is 0, an intermediate voltage in the predetermined voltage range (that is, an M voltage described later which is an intermediate voltage between the H voltage and the L voltage). Is applied (details will be described later).

The image processing unit 51 is configured to perform predetermined image processing on an external image input signal. Then, the image processing unit 51 generates instruction signals for the signal driver 7, the reference driver 8, and the scanning driver 9 based on the result of the image processing. Further, the image processing unit 51 corrects each of the generated instruction signals using the difference information from the difference information acquisition unit and the scanning time determined by the scanning time determination unit 53, and each instruction after the correction. The signal is output to the corresponding signal driver 7, reference driver 8, and scan driver 9. Thereby, the signal driver 7, the reference driver 8, and the scanning driver 9 output the signal voltage Vd, the reference voltage Vr, and the scanning voltage Vs, respectively, and an image (information) corresponding to the image input signal is displayed on the display surface. Is displayed.

The frame buffer 52 is configured to be able to store image input signal data for at least one frame. Further, a nonvolatile memory is used as the frame buffer 52, and the frame buffer 52 constitutes a storage medium that holds data of an image input signal of the last frame in the previous display operation.

The scanning time determination unit 53 determines the scanning time in the scanning operation based on the difference information from the difference information acquisition unit. As a result, the display element 10 of the present embodiment can perform a display operation at high speed even when gradation display is performed (details will be described later).

Further, as shown in FIG. 3, the signal driver 7 is provided with a difference information acquisition unit 71, a shift register 72, and a level shifter 73. The difference information acquisition unit 71 is provided with a frame memory 71a as a memory. The frame memory 71a is configured to be capable of storing image input signal data for at least one frame. In addition, the difference information acquisition unit 71 is configured to obtain a difference between gradation values in two consecutive frames for each pixel area using an image input signal from the outside, and acquire the difference information as difference information. Then, the difference information acquisition unit 71 outputs the acquired difference information to the scanning time determination unit 53 of the display control unit 50.

Further, when the image display device 1 is turned on and performs a display operation for the first time, the difference information acquisition unit 71 stores the image input signal of the last frame in the previous display operation held in the frame buffer 52. The difference information is acquired using the data of the first frame and the image input signal data of the first frame in the current display operation.

In the above description, a case where a nonvolatile memory is used as the frame buffer 52 and the frame buffer 52 is configured as a storage medium that holds image input signal data of the last frame in the previous display operation will be described. did. However, the present embodiment is not limited to this. For example, a nonvolatile storage device provided outside the display control unit 50 can be used as the storage medium. In other words, the present embodiment is not limited as long as the above-described storage medium is provided so that the operation of the difference information acquisition unit 71 and the operation of the display element 10 can be performed smoothly. When the external storage device is used as a storage medium, a volatile memory can be used as the frame buffer 52.

The shift register 72 is configured to supply the corresponding signal voltage Vd from the level shifter 73 to the plurality of signal electrodes 4 according to the scanning operation based on the instruction signal from the image processing unit 51. Specifically, the shift register 72 is supplied with a start pulse and a clock signal included in the instruction signal from the image processing unit 51, and the shift register 72 receives the input start pulse and Based on the clock signal, the level shifter 73 is operated in units of scanning operation for each line. In addition, a plurality of (all) signal electrodes 4 are connected to the level shifter 73, and in response to an operation instruction from the shift register 72, an instruction signal from the image processing unit 51 is sent to all the signal electrodes 4. The corresponding signal voltage Vd is applied to the corresponding signal electrodes 4 all at once.

Further, the reference driver 8 is configured using a general-purpose driver, and the reference driver 8 is provided with a shift register 81 and a level shifter 82 as shown in FIG. Based on the instruction signal from the image processing unit 51, the shift register 81 supplies the corresponding reference voltage Vr from the level shifter 82 to the plurality of reference electrodes 5 in accordance with the scanning operation. Specifically, the shift register 81 is supplied with a start pulse and a clock signal included in the instruction signal from the image processing unit 51. The shift register 81 receives the input start pulse and The level shifter 82 is operated based on the clock signal. In addition, a plurality of (all) reference electrodes 5 are connected to the level shifter 82, and according to an operation instruction from the shift register 81, a selection voltage or a reference voltage Vr according to an instruction signal from the image processing unit 51. A non-selection voltage is applied to the reference electrode 5.

Similarly to the reference driver 8, the scan driver 9 is configured by using a general-purpose driver. The scan driver 9 is provided with a shift register 91 and a level shifter 92 as shown in FIG. Yes. Based on the instruction signal from the image processing unit 51, the shift register 91 supplies a corresponding scanning voltage Vs from the level shifter 92 to the plurality of scanning electrodes 6 in accordance with the scanning operation. Specifically, the shift register 91 is supplied with a start pulse and a clock signal included in the instruction signal from the image processing unit 51. The shift register 91 receives the input start pulse and The level shifter 92 is operated based on the clock signal. In addition, a plurality of (all) scanning electrodes 6 are connected to the level shifter 92, and according to an operation instruction from the shift register 91, a selection voltage or a scanning voltage Vs is selected according to an instruction signal from the image processing unit 51. A non-selection voltage is applied to the scan electrode 6.

Here, the pixel structure of the display element 10 will be specifically described with reference to FIGS.

FIG. 6 is an enlarged plan view showing a main part configuration on the upper substrate side shown in FIG. 1 when viewed from the display surface side. FIG. 7 is an enlarged plan view showing the main configuration of the lower substrate side shown in FIG. 1 when viewed from the non-display surface side. FIG. 8A is an enlarged plan view showing a main part configuration in one pixel region of the display element, and FIG. 8B is a sectional view taken along line VIIIb-VIIIb in FIG. 8A. FIG. 9A and FIG. 9B are cross-sectional views showing the main configuration of the display element shown in FIG. 1 during non-CF color display and CF color display, respectively. 6 and 7, for the sake of simplification of the drawing, twelve pixels arranged at the upper left end portion of FIG. 1 among the plurality of pixels provided on the display surface are illustrated. . Further, in FIG. 6, a rail member and a flat plate member which will be described later provided on the non-display surface side are omitted for the sake of clarity.

6 to 9, the display element 10 includes the upper substrate 2 as the first substrate provided on the display surface side and the second substrate provided on the back side (non-display surface side) of the upper substrate 2. The lower substrate 3 as a substrate is provided. In the display element 10, the upper substrate 2 and the lower substrate 3 are arranged at a predetermined distance from each other, so that a predetermined display space S is formed between the upper substrate 2 and the lower substrate 3. . Further, in the display space S, the polar liquid 16 and the insulating oil 17 not mixed with the polar liquid 16 are arranged in the X direction (left and right direction in FIG. 6) in the display space S. The polar liquid 16 can be moved to the later-described effective display area P1 side or the non-effective display area P2 side.

Further, inside the display space S, as will be described in detail later, there is provided a movement space K for moving the oil 17 as the insulating fluid for each of the pixel regions P. According to the movement, the oil 17 can be smoothly and appropriately moved to the effective display area P1 side or the non-effective display area P2 side.

As the polar liquid 16, for example, an aqueous solution containing water as a solvent and a predetermined electrolyte as a solute is used. Specifically, for example, an aqueous solution of 1 mmol / L potassium chloride (KCl) is used for the polar liquid 16. In addition, the polar liquid 16 is a predetermined color, for example, a color colored black with a self-dispersing pigment.

Also, since the polar liquid 16 is colored black, the polar liquid 16 functions as a shutter that allows or blocks light transmission in each pixel. That is, in each pixel of the display element 10, as will be described in detail later, the polar liquid 16 moves inside the display space S on the reference electrode 5 side (effective display region P1 side) or on the scanning electrode 6 side (non-effective display region P2). The display color is changed to either black or RGB by sliding to the side).

The oil 17 is a non-polar, colorless and transparent oil composed of one or more selected from, for example, side chain higher alcohol, side chain higher fatty acid, alkane hydrocarbon, silicone oil, and matching oil. It has been. Further, the oil 17 moves in the moving space K partitioned on the upper substrate 2 side in the display space S as the polar liquid 16 slides.

For the upper substrate 2, a transparent glass material such as a non-alkali glass substrate or a transparent transparent sheet material such as a transparent synthetic resin such as an acrylic resin is used. A color filter layer 11 is formed on the surface of the upper substrate 2 on the non-display surface side. A guide portion 21 having two rail members 21 a and a flat plate member 21 b is formed on the color filter layer 11 on the non-display surface side surface of the upper substrate 2, and moves into the display space S. The work space K is partitioned (details will be described later). Further, a water repellent film 12 is provided on the surface of the upper substrate 2 on the non-display surface side so as to cover the color filter layer 11, the rail member 21a, and the flat plate member 21b.

The lower substrate 3 is made of a transparent glass material such as a transparent glass material such as a non-alkali glass substrate or a transparent synthetic resin such as an acrylic resin, like the upper substrate 2. Further, the reference electrode 5 and the scan electrode 6 are provided on the surface of the lower substrate 3 on the display surface side, and a dielectric layer 13 is formed so as to cover the reference electrode 5 and the scan electrode 6. Is formed. Further, a rib 14 having ribs 14a and 14b provided in parallel to the Y direction and the X direction is provided on the surface of the dielectric layer 13 on the display surface side. The ribs 14 are provided so as to hermetically divide the inside of the display space S in accordance with the pixel area P, and are configured in a frame shape for each pixel area P as illustrated in FIG.

In the lower substrate 3, the signal electrode 4 is formed so as to penetrate the rib 14 a on the surface of the dielectric layer 13. Further, in the lower substrate 3, a water repellent film 15 is provided so as to cover the signal electrode 4, the dielectric layer 13, and the ribs 14a and 14b.

Also, for example, a backlight 18 that emits white illumination light is integrally assembled on the back side (non-display surface side) of the lower substrate 3, and the transmissive display element 10 is configured. The backlight 18 uses a light source such as a cold cathode fluorescent tube or an LED.

The color filter layer 11 includes red (R), green (G), and blue (B) color filter portions 11r, 11g, and 11b, and a black matrix portion 11s as a light shielding film. The pixels of each color of RGB are configured. That is, in the color filter layer 11, as illustrated in FIG. 6, RGB color filter portions 11 r, 11 g, and 11 b are sequentially provided along the X direction, and each of the four color filter portions 11 r, 11 g, and 11 b is Y A total of 12 pixels are arranged in the X direction and the Y direction, respectively, 3 pixels and 4 pixels.

In the display element 10, as illustrated in FIG. 6, in each pixel region P, any one of RGB color filter portions 11 r, 11 g, and 11 b is provided at a location corresponding to the effective display region P 1 of the pixel. A black matrix portion 11s is provided at a location corresponding to the ineffective display area P2. That is, in the display element 10, an ineffective display region P2 (non-opening portion) is set for the display space S by the black matrix portion (light-shielding film) 11s, and an opening portion (non-opening portion) formed in the black matrix portion 11s ( That is, the effective display area P1 is set by any one of the color filter portions 11r, 11g, and 11b).

In the display element 10, the area of the color filter portions 11r, 11g, and 11b is selected to be the same or slightly smaller than the area of the effective display area P1. On the other hand, the area of the black matrix portion 11s is selected to be the same or slightly larger than the area of the ineffective display area P2. In FIG. 6, in order to clarify the boundary portion between adjacent pixels, the boundary line between two black matrix portions 11 s corresponding to the adjacent pixels is indicated by a dotted line. Then, there is no boundary line between the black matrix portions 11s.

Further, in the display element 10, the display space S is divided in units of pixel areas P by the ribs 14 as the partition walls. That is, in the display element 10, the display space S of each pixel is partitioned by two ribs 14a facing each other and two ribs 14b facing each other as illustrated in FIG. A frame-like rib 14 is provided for each. Further, in the display element 10, the ribs 14 a and 14 b are provided so that the tip portions thereof are in contact with the upper substrate 2, and the rib 14 partitions the inside of the display space S in an airtight manner according to the pixel region P. It is configured as follows. Further, for example, an epoxy resin resist material is used for the ribs 14a and 14b.

The water-repellent films 12 and 15 are made of a transparent synthetic resin, preferably, for example, a fluorine resin that becomes a hydrophilic layer with respect to the polar liquid 16 when a voltage is applied. Thereby, in the display element 10, the wettability (contact angle) between the polar liquid 16 on each surface side on the display space S side of the upper substrate 2 and the lower substrate 3 can be greatly changed. The moving speed of 16 can be increased. The dielectric layer 13 is made of a transparent dielectric film containing, for example, parylene, silicon nitride, hafnium oxide, zinc oxide, titanium dioxide, or aluminum oxide. The specific thickness dimension of each of the water repellent films 12 and 15 is several tens of nm to several μm, and the specific thickness dimension of the dielectric layer 13 is several hundred nm. Further, the water repellent film 15 does not electrically insulate the signal electrode 4 from the polar liquid 16 and does not hinder the improvement of the response of the polar liquid 16.

For the reference electrode 5 and the scanning electrode 6, a transparent electrode material such as indium oxide (ITO), tin oxide (SnO ₂ ), or zinc oxide (AZO, GZO, or IZO) is used. Each of these reference electrodes 5 and each scanning electrode 6 is formed in a strip shape on the lower substrate 3 by a known film forming method such as sputtering.

The signal electrode 4 uses a linear wiring arranged so as to be parallel to the X direction. The signal electrode 4 is made of a transparent electrode material such as ITO. Further, the signal electrode 4 is disposed on the dielectric layer 13 so as to pass through the rib 14 a so as to pass through substantially the center of each pixel region P in the Y direction. It is configured to be in electrical contact with the polar liquid 16. Thereby, in the display element 10, the response of the polar liquid 16 during the display operation is improved.

Further, as shown in FIGS. 8A to 9B, in the display element 10 of the present embodiment, the guide portion 21 is provided on the non-display surface side of the upper substrate 2. The guide portion 21 includes a plurality of, for example, two rail members 21 a provided at a predetermined interval on the surface of the upper substrate 2 on the non-display surface side, and two so as to face the upper substrate 2. And a flat plate member 21b that is connected to each tip portion of the rail member 21a and is formed in a planar shape so as to come into contact with the polar liquid 16 inside the display space S.

In the movement space K, the guide portion 21 is provided with one end portion side and the other end portion side on the effective display region P1 side and the non-effective display region P2 side, respectively, and oil 17 according to the movement of the polar liquid 16. Is guided to the effective display area P1 side or the non-effective display area P2 side. In the display element 10 of the present embodiment, for example, as shown in FIG. 8B, the movement space K for moving the oil (insulating fluid) 17 in each pixel region P is the display space S. Is formed on the upper substrate 2 side of the space in which the polar liquid 16 moves.

Each rail member 21a protrudes from the upper substrate 2 side to the inside of the display space S, and connects the effective display area P1 and the ineffective display area P2 on the upper substrate 2 side. It is provided in a straight line. Further, the flat plate member 21b is connected to the tip portions of the two rail members 21a so that a tunnel-like movement space K is formed between the two rail members 21a and the upper substrate 2. ing. For example, an epoxy resin resist material is used for each rail member 21a and flat plate member 21b. Further, since each rail member 21a and the flat plate member 21b are not provided on the lower substrate 3 side where the signal electrode 4, the reference electrode 5, the scanning electrode 6, and the dielectric layer 13 are installed, each rail member 21a and the flat plate member 21b are provided. The member 21b is configured not to inhibit the movement of the polar liquid 16 due to the electrowetting phenomenon.

Further, in the two rail members 21a and the flat plate member 21b, as shown in FIGS. 8A and 8B, between the rib member 14a and the rail member 21a and the flat plate member 21b adjacent to the rib 14a. The dimension h2 and the dimension h3 between the rib 14b and the rail member 21a and the flat plate member 21b adjacent to the rib 14b are larger than the dimension H of the polar liquid 16 in the direction perpendicular to the upper substrate 2 and the lower substrate 3, respectively. Small dimensions are set. Specifically, in the present embodiment, the dimensions h2 and h3 are each set to 10 μm, for example, and the dimension H is set to 40 μm, for example. The dimension h1 between the two adjacent rail members 21a is set to 50 μm, for example, but the gap between the two rail members 21a is covered with the flat plate member 21b, so that the polar liquid 16 does not enter.

As described above, by using the dimensions h2 and h3 smaller than the dimension H, in this embodiment, it is possible to prevent the operation (movement) of the polar liquid 16 from becoming unstable. That is, according to the experiment by the inventors of the present invention, the polar liquid 16 is applied between the rib 14a and the rail member 21a and the flat plate member 21b adjacent to the rib 14a, and between the rib 14b and the rib 14b. It can prevent entering between each between the member 21a and the flat plate member 21b. As a result, in this embodiment, it is possible to prevent the operation of the polar liquid 16 from becoming unstable. According to an experiment by the inventors of the present invention, for example, when the dimension h2 between the rib 14a and the rail member 21a and the flat plate member 21b adjacent to the rib 14a is equal to or larger than the dimension H of the polar liquid 16, The polar liquid 16 entered between the rib 14a and the rail member 21a and the flat plate member 21b adjacent to the rib 14a, and the operation of the polar liquid 16 was not stable.

In the above description, the pixel region P is hermetically separated by the ribs 14 and the moving space K is provided by installing the guide portion 21 to smoothly move the oil (insulating fluid) 17. . However, the display element 10 according to the present embodiment is not limited to this, and the upper substrate 2 and the lower substrate 3 (at least one side of the first and second substrates) are provided in accordance with the plurality of pixel regions P. Any rib that can easily prevent the polar liquid 16 from being coalesced between the adjacent pixel regions P by providing ribs that divide the interior of the display space S may be used.

Specifically, for example, ribs 14a and 14b are provided on the lower substrate 3 side so that a gap is generated between the upper substrate 2 and the non-display surface side, or gaps are generated at the four corners of the pixel region P. As described above, the configuration may be such that the ends of the ribs 14a and 14b are provided on the lower substrate 3 side in a state of being separated from each other. When such a gap is provided, the installation of the moving space K for the insulating fluid can be omitted.

Next, the display operation of the image display device 1 of the present embodiment configured as described above will be specifically described with reference to FIGS.

FIG. 10 is a diagram for explaining an operation example of the image display device. FIG. 11 is a diagram for explaining specific operations of the signal driver, the reference driver, and the scan driver shown in FIG. 1 in two consecutive frames, and FIG. 11A and FIG. FIG. 11C is a diagram showing a specific display image of two consecutive frames, and FIG. 11C is a diagram showing a difference image of the two frames. FIG. 12A to FIG. 12D are diagrams for explaining a specific voltage application operation of the signal driver. FIGS. 13A to 13B are diagrams for explaining another specific voltage application operation of the signal driver.

First, with reference to FIG. 10, the basic display operation of the image display apparatus 1 of the present embodiment will be specifically described.

In FIG. 10, the reference driver 8 and the scanning driver 9 select the reference voltage Vr and the scanning voltage Vs as the reference voltage Vr and the scanning voltage Vs, respectively, for the reference electrode 5 and the scanning electrode 6 in a predetermined scanning direction from the left side to the right side in FIG. Apply voltage sequentially. Specifically, the reference driver 8 and the scan driver 9 sequentially apply an H voltage (first voltage) and an L voltage (second voltage) as selection voltages to the reference electrode 5 and the scan electrode 6, respectively. The scanning operation for selecting the line is performed. In this selection line, the signal driver 7 applies the H voltage or the L voltage as the signal voltage Vd to the corresponding signal electrode 4 according to the image input signal from the outside. Thereby, in each pixel of the selection line, the polar liquid 16 is moved to the effective display area P1 side or the non-effective display area P2 side, and the display color on the display surface side is changed. At this time, the oil 17 passes through the inside of the movement space K in accordance with the movement of the polar liquid 16, and the ineffective display area P2 side or the effective display area on the side opposite to the movement destination of the polar liquid 16. Moved to the P1 side.

On the other hand, the reference driver 8 and the scan driver 9 apply the non-selection voltage as the reference voltage Vr and the scan voltage Vs to the non-selected lines, that is, all the remaining reference electrodes 5 and scan electrodes 6, respectively. Specifically, the reference driver 8 and the scan driver 9 apply an intermediate voltage (Middle) that is, for example, an intermediate voltage between the H voltage and the L voltage to the remaining reference electrodes 5 and scan electrodes 6 as non-selection voltages. Voltage, hereinafter referred to as “M voltage”). Thereby, in each pixel of the non-selected line, the polar liquid 16 is stopped without causing unnecessary fluctuation on the effective display region P1 side or the non-effective display region P2 side, and the display color on the display surface side is not changed.

When performing the display operation as described above, combinations of voltages applied to the reference electrode 5, the scan electrode 6, and the signal electrode 4 are as shown in Table 1. Further, as shown in Table 1, the behavior of the polar liquid 16 and the display color on the display surface side are in accordance with the applied voltage. In Table 1, the H voltage, L voltage, and M voltage are abbreviated as “H”, “L”, and “M”, respectively (the same applies to Table 2 described later). Specific values of the H voltage, the L voltage, and the M voltage are, for example, + 16V, 0V, and + 8V, respectively.

<Operation on selected line>
In the selection line, for example, when an H voltage is applied to the signal electrode 4, an H voltage is applied between the reference electrode 5 and the signal electrode 4. There is no potential difference with the electrode 4. On the other hand, since the L voltage is applied to the scan electrode 6 between the signal electrode 4 and the scan electrode 6, a potential difference is generated. Therefore, the polar liquid 16 moves in the display space S toward the scanning electrode 6 where a potential difference is generated with respect to the signal electrode 4. As a result, as illustrated in FIG. 9B, the polar liquid 16 is moved to the ineffective display area P <b> 2 side, and the oil 17 is moved to the reference electrode 5 side to illuminate light from the backlight 18. Is allowed to reach the color filter portion 11r. As a result, the display color on the display surface side is in a red display (CF color display) state by the color filter unit 11r. In the image display device 1, in all three adjacent RGB pixels, when the polar liquid 16 moves to the ineffective display area P <b> 2 side and CF colored display is performed, from the RGB pixels. The red light, green light, and blue light are mixed with white light, and white display is performed.

On the other hand, when the L voltage is applied to the signal electrode 4 in the selection line, a potential difference is generated between the reference electrode 5 and the signal electrode 4, and between the signal electrode 4 and the scanning electrode 6. No potential difference has occurred. Accordingly, the polar liquid 16 moves in the display space S toward the reference electrode 5 where a potential difference is generated with respect to the signal electrode 4. As a result, as illustrated in FIG. 9A, the polar liquid 16 is moved to the effective display area P1 side, and the illumination light from the backlight 18 is prevented from reaching the color filter unit 11r. Thereby, the display color on the display surface side is in a black display (non-CF color display) state by the polar liquid 16.

<Operation on unselected lines>
In the non-selected line, for example, when the H voltage is applied to the signal electrode 4, the polar liquid 16 is maintained in a stationary state at the current position and is maintained at the current display color. That is, since the M voltage is applied to both the reference electrode 5 and the scan electrode 6, the potential difference between the reference electrode 5 and the signal electrode 4 and the potential difference between the scan electrode 6 and the signal electrode 4 are This is because the same potential difference occurs in both cases. As a result, the display color is maintained unchanged from the current black display or CF color display.

Similarly, even when the L voltage is applied to the signal electrode 4 in the non-selected line, the polar liquid 16 is maintained in a stationary state at the current position and is maintained in the current display color. That is, since the M voltage is applied to both the reference electrode 5 and the scan electrode 6, the potential difference between the reference electrode 5 and the signal electrode 4 and the potential difference between the scan electrode 6 and the signal electrode 4 are This is because the same potential difference occurs in both cases.

As described above, in the non-selected line, even if the signal electrode 4 is at either the H voltage or the L voltage, the polar liquid 16 does not move but remains stationary and the display color on the display surface side. Does not change.

On the other hand, in the selection line, the polar liquid 16 can be moved according to the voltage applied to the signal electrode 4 as described above, and the display color on the display surface side can be changed.

Further, in the image display device 1, the display color at each pixel on the selected line is applied to the signal electrode 4 corresponding to each pixel, for example, as shown in FIG. 10 by the combination of applied voltages shown in Table 1. Depending on the voltage, the color filter portions 11r, 11g, and 11b are CF colored (red, green, or blue) or the non-CF colored (black) by the polar liquid 16. Further, when the reference driver 8 and the scanning driver 9 perform the scanning operation of the selection lines of the reference electrode 5 and the scanning electrode 6 from the left to the right in FIG. 10, for example, The display color also changes sequentially from left to right in FIG. Therefore, by performing the scanning operation of the selected line by the reference driver 8 and the scanning driver 9 at high speed, the display color of each pixel on the display unit can be changed at high speed in the image display device 1. Furthermore, by applying the signal voltage Vd to the signal electrode 4 in synchronization with the scanning operation of the selected line, the image display apparatus 1 can perform various information including moving images based on an external image input signal. Can be displayed.

Further, the combinations of voltages applied to the reference electrode 5, the scan electrode 6, and the signal electrode 4 are not limited to Table 1 but may be those shown in Table 2.

That is, the reference driver 8 and the scan driver 9 are, for example, in a predetermined scanning direction from the left side to the right side in the figure, with respect to the reference electrode 5 and the scan electrode 6 as L voltage (second voltage) and H as selection voltages. A scanning operation is performed in which a voltage (first voltage) is sequentially applied to select lines. In this selection line, the signal driver 7 applies the H voltage or the L voltage as the signal voltage Vd to the corresponding signal electrode 4 according to the image input signal from the outside.

On the other hand, the reference driver 8 and the scan driver 9 apply the M voltage as the non-selection voltage to the non-selected lines, that is, all the remaining reference electrodes 5 and scan electrodes 6.

<Operation on selected line>
In the selection line, for example, when the L voltage is applied to the signal electrode 4, the L voltage is applied between the reference electrode 5 and the signal electrode 4. There is no potential difference with the electrode 4. On the other hand, since the H voltage is applied to the scanning electrode 6 between the signal electrode 4 and the scanning electrode 6, a potential difference is generated. Accordingly, the polar liquid 16 moves in the display space S toward the scanning electrode 6 where a potential difference is generated with respect to the signal electrode 4. As a result, as illustrated in FIG. 9B, the polar liquid 16 is moved to the ineffective display area P <b> 2 side, and the oil 17 is moved to the reference electrode 5 side to illuminate light from the backlight 18. Is allowed to reach the color filter portion 11r. As a result, the display color on the display surface side is in a red display (CF color display) state by the color filter unit 11r. Similarly to the case shown in Table 1, when CF colored display is performed on all three adjacent RGB pixels, white display is performed.

On the other hand, when the H voltage is applied to the signal electrode 4 in the selection line, a potential difference is generated between the reference electrode 5 and the signal electrode 4, and between the signal electrode 4 and the scanning electrode 6. No potential difference has occurred. Accordingly, the polar liquid 16 moves in the display space S toward the reference electrode 5 where a potential difference is generated with respect to the signal electrode 4. As a result, as illustrated in FIG. 9A, the polar liquid 16 is moved to the effective display area P1 side, and the illumination light from the backlight 18 is prevented from reaching the color filter unit 11r. Thereby, the display color on the display surface side is in a black display (non-CF color display) state by the polar liquid 16.

<Operation on unselected lines>
In the non-selected line, for example, when the L voltage is applied to the signal electrode 4, the polar liquid 16 is maintained in a stationary state at the current position and is maintained at the current display color. That is, since the M voltage is applied to both the reference electrode 5 and the scan electrode 6, the potential difference between the reference electrode 5 and the signal electrode 4 and the potential difference between the scan electrode 6 and the signal electrode 4 are This is because the same potential difference occurs in both cases. As a result, the display color is maintained unchanged from the current black display or CF color display.

Similarly, even when the H voltage is applied to the signal electrode 4 in the non-selected line, the polar liquid 16 is maintained in a stationary state at the current position and is maintained at the current display color. That is, since the M voltage is applied to both the reference electrode 5 and the scan electrode 6, the potential difference between the reference electrode 5 and the signal electrode 4 and the potential difference between the scan electrode 6 and the signal electrode 4 are This is because the same potential difference occurs in both cases.

As described above, even in the case shown in Table 2, as in the case shown in Table 1, in the non-selected line, even if the signal electrode 4 is either the H voltage or the L voltage, the polar liquid 16 does not move and is stationary, and the display color on the display surface side does not change.

On the other hand, in the selection line, the polar liquid 16 can be moved according to the voltage applied to the signal electrode 4 as described above, and the display color on the display surface side can be changed.

Further, in the image display device 1 of the present embodiment, in addition to the combinations of applied voltages shown in Tables 1 and 2, the applied voltage to the signal electrode 4 is not limited to the binary value of the H voltage or the L voltage. The voltage between the H voltage and the L voltage can be changed according to information displayed on the display surface side. In other words, the image display device 1 can perform gradation display by controlling the signal voltage Vd. Thereby, the display element 10 excellent in display performance can be configured.

Next, specific operation examples of the difference information acquisition unit 71 and the scanning time determination unit 53 in the image display apparatus 1 of the present embodiment will be mainly described with reference to FIGS.

In FIGS. 11 (a) to 11 (c), the lower left hatching indicates that non-CF colored display, that is, black display is performed, and the lower right hatching indicates CF colored display, for example, red display. Indicates that it will be done. Further, in these black display and red display, the gradation value for each pixel region P included in the image input signal is the minimum value and the maximum value (for example, when performing gradation display of 256 gradations, It is assumed that the gradation values are “0” and “255”. Further, in FIGS. 11A to 11C, it is assumed that the scanning operation for each line is performed along the arrows in the figure.

As shown in FIG. 11A, among the two consecutive frames, the display image F1 of the previous frame is included from line A to line B on the display surface and from pixel area E to pixel area F. In all the pixel areas P, red display is performed, and in all other pixel areas P, black display is performed. Further, the image input signal data including the gradation value for each pixel region P of the display image F1 is held in the frame memory 71a in the difference information acquisition unit 71.

In addition, as shown in FIG. 11B, the display image F2 of the subsequent frame of the two consecutive frames is included in the display surface from line C to line D, and from the pixel region E to the pixel region. In all the pixel regions P up to F, red display is performed, and in all other pixel regions P, black display is performed. The image input signal data including the gradation value for each pixel region P of the display image F 2 is held in the frame buffer 52 in the display control unit 50. Then, the display control unit 50 outputs the data of the image input signal of the display image F <b> 2 held in the frame buffer 52 to the difference information acquisition unit 71 of the signal driver 7.

Subsequently, the difference information acquisition unit 71 stores the image input signal data (tone value) of the display image F1 held in the frame memory 71a and the image input signal data (display value F2) from the display control unit 50 ( The difference between the gradation values in two consecutive frames is obtained for each pixel region P and obtained as difference information. Then, the difference information acquisition unit 71 outputs the acquired difference information to the scanning time determination unit 53 in the display control unit 50.

Thereafter, the scanning time determination unit 53 determines the scanning time in the scanning operation based on the difference information from the difference information acquisition unit 71. Specifically, as shown in FIG. 11C, the scanning time determination unit 53 is included in the difference image F3 of two consecutive frames from the line A to the line C on the display surface, and the pixels In all the pixel areas P from the area E to the pixel area F, it is determined that the red display is changed to the black display based on the difference information (that is, the gradation value difference is 255 (= 255-0)). .

Further, the scanning time determination unit 53 includes the difference information (that is, the difference information (that is, the pixel area P from the pixel area E to the pixel area F) in the difference image F3 from the line B to the line D on the display surface). Based on the difference between the gradation values of −255 (= 0−255), it is determined that the black display is changed to the red display.

Further, the scanning time determination unit 53 does not hatch the pixel area P other than the pixel area P that is changed from the red display to the black display or changed from the black display to the red display in the difference image F3 (ie, FIG. 11C). In the pixel region P), the display of the same color as the display image F1, that is, the display color, based on the difference information (that is, the gradation value difference is 0 = (255-255 or = 0-0)) Determine that is not changed.

Then, the scanning time determination unit 53 determines from the line A to the line C determined to be changed from the red display to the black display, and from the line B to the line D determined to be changed from the black display to the red display. In the line, the scanning operation is determined to be performed at a predetermined scanning time. Further, the predetermined scanning time is a time required to move the polar liquid 16 to the maximum extent, that is, a state where the polar liquid 16 is located at the leftmost end in the display space S of the pixel region P (FIG. 9). (See (a)) and the state in which the polar liquid 16 is located at the rightmost end in the display space S of the pixel region P (see FIG. 9B) from one state to the other state. It is defined by the voltage application time required to move to.

On the other hand, the scanning time determination unit 53 determines that the display color is not changed, that is, the line from the first line below the line C to the line B from the first line at the top to the line one above the line A. The scanning time is set to a value of “0” from the predetermined scanning time up to the line one above and from the line below the line D to the last line at the bottom. That is, the scanning time determination unit 53 does not perform the scanning operation on the line for which it is determined that the display color is not changed, and the reference driver 5 and the scanning driver 9 respectively apply the corresponding reference electrode 5 and scanning electrode 6 to the corresponding line. It is determined to maintain the application of the non-selection voltage without applying the selection voltage.

Subsequently, the scanning time determination unit 53 notifies the image processing unit 51 of the determined scanning time for each line along with the difference information from the difference information acquisition unit 71.

Thereafter, the difference acquired by the difference information acquisition unit 71 for each instruction signal to the signal driver 7, the reference driver 8, and the scanning driver 9 generated by the image processing unit 51 based on the image input signal from the outside. The correction is performed using the information and the scanning time determined by the scanning time determination unit 53, and each corrected instruction signal is output to the corresponding signal driver 7, reference driver 8, and scanning driver 9. Thereby, the signal driver 7, the reference driver 8, and the scan driver 9 allow the signal electrode 4, the reference electrode 5, and the scan electrode 6 so that the scanning operation is performed with a predetermined scanning time in the line where the display color is changed. A voltage is applied to each.

Specifically, as shown in FIG. 12A, in the pixel region P that is changed from red display to black display, for example, the pixel region E of the line A, the signal driver 7 corresponds to the pixel region E. An L voltage is applied to the signal electrode 4 to move the polar liquid 16 to the effective display region P1 side during a predetermined scanning time from the time point T1 to the time point T2.

Further, in this line A, the pixel area P whose display color is not changed, that is, the pixel area P from the left end pixel area LE (FIG. 11) to the pixel area E to the left of the pixel area E, and the display area In the pixel region P from the pixel region right next to the pixel region F to the rightmost pixel region RE (FIG. 11), the signal driver 7 applies the M voltage to the signal electrode 4 corresponding to each pixel region P. (Intermediate voltage) is applied. That is, as described above, in the display control unit 50, in the plurality of pixel regions P in which the image processing unit 51 is symmetric with respect to one scanning operation, the difference value of the gradation value in two consecutive frames is 0. When it is determined that a value is included, an intermediate voltage in the middle of the predetermined voltage range is applied to the signal electrode 4 corresponding to the pixel region P whose difference value is 0. ing.

Specifically, as shown in FIG. 12B, in the plurality of pixel regions P in which the display color is not changed, the signal driver 7 performs a predetermined scanning time (from time T1 to time) in the scanning operation for the line A. (Up to T2), an M voltage (intermediate voltage) is applied to the signal electrode 4 corresponding to each of the pixel regions P.

Further, as shown in FIG. 12C, in the pixel region P that is changed from black display to red display, for example, the pixel region F of the line D, the signal driver 7 applies the signal electrode 4 corresponding to the pixel region F. On the other hand, during a predetermined scanning time from the time point T3 to the time point T4, an H voltage that moves the polar liquid 16 to the ineffective display region P2 side is applied.

Further, in this line D, the pixel area P from which the display color is not changed, that is, the pixel area P from the left end pixel area LE (FIG. 11) to the pixel area E to the left of the pixel area E, and the display area In the pixel region P from the pixel region right next to the pixel region F to the rightmost pixel region RE (FIG. 11), the signal driver 7 applies the M voltage to the signal electrode 4 corresponding to each pixel region P. (Intermediate voltage) is applied.

Specifically, as shown in FIG. 12D, in the plurality of pixel regions P in which the display color is not changed, the signal driver 7 performs a predetermined scanning time (from time T3 to time) in the scanning operation for the line D. In the period up to T4), an M voltage (intermediate voltage) is applied to the signal electrode 4 corresponding to each of the pixel regions P.

Next, in the image display device 1 of the present embodiment, red display (gradation value, 255) to black display (gradation value, 0) or black display (gradation value, 0) to red display (gradation value, A case where gradation display other than 255) is performed will be described.

First, for example, in line A, an operation in the pixel region P1 in which gradation display of halftone between red display and black display is performed from red display will be described.

In such a pixel region P1, when the difference information acquisition unit 71 acquires, for example, a value of 180 (= 255-75) as the difference information, that is, the value of the gradation value difference, the scanning time determination unit 53 Based on the difference value (180) in the pixel region P1, the voltage application time (that is, the signal corresponding to the signal driver 7) is a substantial scanning time for moving the polar liquid 16 in a predetermined scanning time. Time for applying the L voltage to the electrode 4) is determined. Specifically, the voltage application time is obtained by a ratio of the difference value of the gradation value with respect to the predetermined scanning time, that is, the predetermined scanning time × 180 ÷ 255.

The scanning time determination unit 53 notifies the image processing unit 51 of the determined voltage application time and the difference information from the difference information acquisition unit 71. Thereafter, the image processing unit 51 applies to the signal driver 7 a voltage application time for applying the L voltage in the pixel region P <b> 1 and a voltage application for applying the M voltage that stops the polar liquid 16 during a predetermined scanning time. A time (= predetermined scanning time−voltage application time for applying the L voltage) is included in the instruction signal and designated. Accordingly, as shown in FIG. 13A, the signal driver 7 in the pixel region P <b> 1 has a predetermined time from time T <b> 1 to time T <b> 2 with respect to the signal electrode 4 corresponding to the pixel region P <b> 1. In the scanning time, the L voltage is applied from the time point T1 to the time point T2 ′, the polar liquid 16 is moved, and then the M voltage is applied from the time point T2 ′ to the time point T2. The liquid 16 is stopped at the moved position.

Next, for example, in line D, an operation in the pixel region P2 in which the gray scale display from the black display to the black display and the red display is performed will be described.

In such a pixel region P2, when the difference information acquisition unit 71 acquires, for example, a value of −120 (= 0−120) as the difference information, that is, the value of the gradation value difference, the scanning time determination unit 53 Based on the difference value (−120) in the pixel region P1, the voltage application time (that is, the signal driver 7) corresponds to a substantial scanning time for moving the polar liquid 16 in a predetermined scanning time. The time during which the H voltage is applied to the signal electrode 4 is determined. Specifically, the voltage application time is obtained by a ratio of the difference value of the gradation value with respect to the predetermined scanning time, that is, the predetermined scanning time × 120 ÷ 255.

The scanning time determination unit 53 notifies the image processing unit 51 of the determined voltage application time and the difference information from the difference information acquisition unit 71. Thereafter, the image processing unit 51 applies to the signal driver 7 a voltage application time for applying the H voltage in the pixel region P2 and a voltage application for applying the M voltage for stopping the polar liquid 16 within a predetermined scanning time. A time (= predetermined scanning time−voltage application time for applying the H voltage) is included in the instruction signal and designated. Accordingly, as shown in FIG. 13B, the signal driver 7 in the pixel region P2 has a predetermined time from time T3 to time T4 with respect to the signal electrode 4 corresponding to the pixel region P2. The H voltage is applied from the time point T3 to the time point T4 ′ and the polar liquid 16 is moved, and then the M voltage is applied from the time point T4 ′ to the time point T4. The liquid 16 is stopped at the moved position.

In addition to the above description, after the M voltage that does not move the polar liquid 16 is applied first in a predetermined scanning time, the H voltage or the L voltage that moves the polar liquid 16 is applied, or the M voltage is applied. The time and the application time for applying the H voltage or the L voltage may be divided into a plurality of times, and the time for applying the M voltage, the H voltage, or the L voltage may be alternately provided within a predetermined scanning time.

Further, gradation display from a gradation value other than the maximum value (255) or minimum value (0) of the gradation value to a different gradation value is similarly performed based on the difference value of the gradation value. The application time of the H voltage or the L voltage and the M voltage is obtained and performed.

On the other hand, in the line where the display color is not changed, the signal driver 7, the reference driver 8, and the scanning driver 9 operate only the shift registers 72, 81, and 91, respectively, and perform the following operation without performing the scanning operation. Perform an operation to select a line.

In the display element 10 of the present embodiment configured as described above, the difference information acquisition unit 71 uses the image input signal from the outside to calculate the difference between the tone values in two consecutive frames for each pixel region P. Obtained and acquired as difference information. The scanning time determination unit 53 determines the scanning time for the scanning operation based on the difference information from the difference information acquisition unit 71. Further, in the display control unit 50, the image processing unit 51 uses the difference information from the difference information acquisition unit 71 and the scanning time from the scanning time determination unit 53 to use the signal driver (signal voltage application unit) 4 and the reference driver (reference). Each instruction signal to the voltage application unit 5 and the scan driver 6 is generated, and a scanning operation corresponding to the scanning time is performed. Thus, in the present embodiment, unlike the conventional example, it is possible to configure the display element 10 that can perform a display operation at high speed even when performing gradation display. That is, as illustrated in FIG. 11, in the display element 10 of the present embodiment, the display color in each pixel region P of one line is not changed (the gradation value is the same) in two consecutive frames. Since the scanning operation is not performed on that line, the display operation can be performed at high speed even when gradation display is performed. In addition, since the display operation can be performed at a high speed as described above, the display element 10 according to the present embodiment can change the display color at a high speed even when the display surface is enlarged.

Further, in the display element 10 of the present embodiment, the display control unit 50 sets a value of 0 to the difference value of the gradation values in two consecutive frames in a plurality of pixel regions P that are symmetric with respect to one scanning operation. Is determined, the intermediate voltage in the middle of the predetermined voltage range is applied to the signal electrode 4 corresponding to the pixel region P whose difference value is 0. Accordingly, in the present embodiment, the polar liquid 16 can be reliably stopped in the pixel region P where the difference value is 0, and the display quality of the display element 10 can be reliably prevented from deteriorating. .

In the display element 10 of the present embodiment, the difference information acquisition unit 71 uses a frame memory 71a capable of storing image input signal data for at least one frame, so that accurate difference information can be reliably obtained. And can be easily obtained.

In the image display device (electrical device) 1 of the present embodiment, the display element 10 capable of performing a display operation at high speed even when performing gradation display is used for the display unit. It is possible to easily configure a high-performance image display device (electrical device) 1 including a display unit that can be changed.

[Second Embodiment]
FIG. 14 is a block diagram showing a specific configuration of the display control unit of the display element according to the second embodiment of the present invention. In the figure, the main difference between the present embodiment and the first embodiment is that the scanning time depends on the maximum absolute value of the difference between the gradation values included in the difference information from the difference information acquisition unit. The determination unit determines the scanning time in the scanning operation. In addition, about the element which is common in the said 1st Embodiment, the same code | symbol is attached | subjected and the duplicate description is abbreviate | omitted.

That is, as shown in FIG. 14, in the display element 10 of the present embodiment, a scanning time determination unit 53 ′ is provided in the display control unit 50. The scanning time determination unit 53 ′ determines the scanning time in the scanning operation according to the maximum absolute value of the difference between the gradation values included in the difference information from the difference information acquisition unit 71. In other words, in the display element 10 of this embodiment, unlike the first embodiment using the predetermined scanning time defined by the time required to move the polar liquid 16 to the maximum, the difference information acquisition is performed. Using the difference information acquired by the unit 71, the scanning time in the scanning operation is appropriately determined.

Here, with reference to FIG. 15 as well, the display operation in the image display device 1 of the present embodiment will be specifically described. In the following description, a case where the difference values of the gradation values are, for example, 240, 175, -185, and 0 in the pixel regions P3, P4, P5, and P6 included in one line is illustrated. I will explain.

FIGS. 15A to 15D are diagrams for explaining a specific voltage application operation of the signal driver of the display element according to the second embodiment.

In the present embodiment, first, the difference information acquisition unit 71 acquires 240, 175, -185, and 0 as the difference values of the gradation values in the pixel regions P3, P4, P5, and P6, and the difference information To the scanning time determination unit 53 ′. The scanning time determination unit 53 ′ determines 240, which is the maximum absolute value of the difference between the gradation values, from the difference information from the difference information acquisition unit 71, and uses the determined maximum value for the pixel region P3. , P4, P5, and P6, the scanning time in the scanning operation of the line is determined. That is, the scanning time determination unit 53 'determines the scanning time for moving the polar liquid 16 on the line including the pixel regions P3, P4, P5, and P6 based on the determined maximum value. Specifically, this scanning time is obtained by a ratio of the determined maximum value to the maximum time of the absolute difference with respect to the time required to move the polar liquid 16 to the maximum, that is, a predetermined scanning time × 240 ÷ 255. It is done.

Thereafter, the scanning time determination unit 53 'determines a voltage application time for moving the polar liquid 16 in the pixel regions P4, P5, and P6 with reference to the determined scanning time. Specifically, when the predetermined scanning time is TW, the voltage application time for moving the polar liquid 16 in the pixel region P4 is determined by TW × 175 ÷ 240. The voltage application time for moving the polar liquid 16 in the pixel region P5 is determined by TW × | −185 | ÷ 240, and the voltage application time for moving the polar liquid 16 in the pixel region P6 is It is determined by TW × 0 ÷ 240.

The scanning time determination unit 53 ′ notifies the image processing unit 51 of the determined voltage application time and the difference information from the difference information acquisition unit 71. Thereafter, the image processing unit 51 instructs the signal driver 7 by including the voltage application time for applying the H voltage in the pixel region P3 in the instruction signal. Thereby, as shown in FIG. 15A, the signal driver 7 in the pixel region P3, the signal driver 7 applies the signal electrode 4 corresponding to the pixel region P3 from the time T5 to the time T6. The polar liquid 16 is moved by applying an H voltage. In the figure, time T5 to time T7 correspond to the predetermined scanning time. That is, in the present embodiment, unlike the first embodiment, the scanning time in the scanning operation for each line can be shortened depending on the difference value of the gradation values.

Further, the image processing unit 51 applies a voltage application time (= TW × 175 ÷ 240) for applying the H voltage in the pixel region P4 to the signal driver 7 and a voltage for applying the M voltage that causes the polar liquid 16 to stop. An application time (= voltage application time (TW × 175 ÷ 240) for applying the TW−H voltage) is included in the instruction signal and instructed. Accordingly, as shown in FIG. 15B, the signal driver 7 in the pixel region P4 has a time from the time T5 to the time T6 with respect to the signal electrode 4 corresponding to the pixel region P4. Among these, the H voltage is applied from time T5 to time T6 ′ to move the polar liquid 16, and then the M voltage is applied from time T6 ′ to time T6 to cause the polar liquid 16 to flow. Stop at the moved position.

Further, the image processing unit 51 applies a voltage application time (= TW × | −185 | ÷ 240) for applying the L voltage in the pixel region P5 to the signal driver 7 and an M voltage for causing the polar liquid 16 to stop. A voltage application time to be applied (= voltage application time to apply a TW−L voltage (TW × | −185 | ÷ 240)) is included in the instruction signal and designated. Thereby, as shown in FIG. 15C, the signal driver 7 causes the signal driver 7 to perform the signal electrode 4 corresponding to the pixel region P5 from the time T5 to the time T6 ″ in the pixel region P5. After the polar liquid 16 is moved by applying the L voltage, the M voltage is applied from the time T6 ″ to the time T6 and stopped at the position where the polar liquid 16 is moved.

Further, the image processing unit 51 instructs the signal driver 7 by including the time for applying the M voltage in the pixel region P6 in the instruction signal. Thereby, as shown in FIG. 15D, the signal driver 7 in the pixel region P6, the signal driver 7 applies the signal electrode 4 corresponding to the pixel region P6 between time T5 and time T6. The polar liquid 16 is not moved by applying the M voltage.

With the above configuration, the present embodiment can achieve the same operations and effects as the first embodiment. Further, in the present embodiment, the scanning time determination unit 53 ′ determines the scanning time in the scanning operation according to the maximum absolute value of the gradation value difference included in the difference information from the difference information acquisition unit 71. Has been decided. Thereby, in this embodiment, it is possible to determine by shortening the scanning time in the scanning operation in accordance with the display information in two consecutive frames, and even when performing gradation display, the display operation can be performed at a higher speed. Can be made.

[Third Embodiment]
FIG. 16 is a plan view for explaining a display element and an image display apparatus according to the third embodiment of the present invention. FIG. 17 is a block diagram showing a specific configuration of the display control unit shown in FIG. FIG. 18 is a block diagram showing a specific configuration of the signal driver shown in FIG. In the figure, the main difference between the present embodiment and the second embodiment is that a difference information acquisition unit is provided in the display control unit. In addition, about the element which is common in the said 2nd Embodiment, the same code | symbol is attached | subjected and the duplicate description is abbreviate | omitted.

That is, as shown in FIGS. 16 to 18, in the display element 10 of the present embodiment, a difference information acquisition unit 54 is provided inside the display control unit 50 ′. In the display control unit 50 ′, a frame buffer 52 that can store image input signal data for at least two frames is used.

The difference information acquisition unit 54 obtains the difference between the gradation values in two consecutive frames for each pixel area, and acquires it as difference information, as in the second embodiment. Specifically, the difference information acquisition unit 54 compares the image input signal data (gradation values) of two consecutive frames stored in the frame buffer 52 as a memory for each pixel region. The difference information is obtained. Then, the difference information acquisition unit 54 outputs the obtained difference information to the scanning time determination unit 55.

The scanning time determination unit 55 determines the scanning time in the scanning operation based on the difference information from the difference information acquisition unit 54, as in the second embodiment.

On the other hand, the signal driver 7 'is configured by using a general-purpose driver, and the signal driver 7' is provided with a shift register 74 and a level shifter 75 as shown in FIG. Based on the instruction signal from the image processing unit 51, the shift register 74 supplies the corresponding signal voltage Vd from the level shifter 75 to the plurality of signal electrodes 4 according to the scanning operation. More specifically, the shift register 74 is supplied with a start pulse and a clock signal included in the instruction signal from the image processing unit 51. The shift register 74 receives the input start pulse and Based on the clock signal, the level shifter 75 is operated in units of scanning operation for each line. In addition, a plurality of (all) signal electrodes 4 are connected to the level shifter 75, and in response to an operation instruction from the shift register 74, an instruction signal from the image processing unit 51 is sent to all the signal electrodes 4. The corresponding signal voltage Vd is applied to the corresponding signal electrodes 4 all at once.

With the above configuration, the present embodiment can achieve the same operations and effects as those of the second embodiment. In the present embodiment, the difference information acquisition unit 54 is provided in the display control unit 50 ′. Thereby, in this embodiment, unlike the case where the difference information acquisition unit 71 is provided in the signal driver (signal voltage application unit) 7, a general-purpose voltage application unit (driver) is used for the signal driver 7 ′. it can. Further, it is possible to easily output instruction signals from the display control unit 50 ′ to the signal driver 7 ′, the reference driver 8, and the scanning driver 9.

[Fourth Embodiment]
FIG. 19 is a plan view for explaining a display element and an image display apparatus according to the fourth embodiment of the present invention. FIG. 20 is a block diagram showing a specific configuration of the display control unit shown in FIG. FIG. 21 is a block diagram showing a specific configuration of the signal driver shown in FIG. 22 is a block diagram showing a specific configuration of the reference driver shown in FIG. FIG. 23 is a block diagram showing a specific configuration of the scan driver shown in FIG. In the figure, the main difference between the present embodiment and the third embodiment is that scanning that determines whether or not to perform a scanning operation in the display control unit based on the scanning time from the scanning time determination unit. This is the point that an operation determining unit is provided. In addition, about the element which is common in the said 3rd Embodiment, the same code | symbol is attached | subjected and the duplicate description is abbreviate | omitted.

That is, as shown in FIGS. 19 to 23, in the display element 10 of the present embodiment, a scanning operation determining unit 56 is provided inside the display control unit 50 ″. It is configured to determine whether or not to perform a scanning operation based on the scanning time from the time determining unit 55. Specifically, the scanning operation determining unit 56 scans from the scanning time determining unit 55. Using the time, it is determined whether or not the scanning operation is performed, and the address of the line determined to perform the scanning operation is acquired.

Then, the scanning operation determination unit 56 notifies the image processing unit 51 of the acquired address. The image processing unit 51 performs scanning determined by the scanning time determining unit 55 for each instruction signal to the signal driver 7 ″, the reference driver 8 ″, and the scanning driver 9 ″ that has been generated based on an image input signal from the outside. In addition, the image processing unit 51 includes the address of the line determined to perform the scanning operation from the scanning operation determining unit 56 in each instruction signal described above, and the corresponding signal driver 7 ″, Output to the reference driver 8 "and the scanning driver 9".

Further, the signal driver 7 ″ is configured by using a general-purpose driver, and the signal driver 7 ″ is provided with a decoder 76 and a level shifter 77 as shown in FIG. The decoder 76 extracts an address included in the instruction signal from the image processing unit 51 and determines a line on which a scanning operation is performed. Then, the decoder 76 instructs the level shifter 77 to apply the signal voltage Vd corresponding to the instruction signal from the image processing unit 51 to the corresponding signal electrode 4 for the determined line. In addition, a plurality of (all) signal electrodes 4 are connected to the level shifter 77, and in accordance with an operation instruction from the decoder 76, an image processing unit is provided for all the signal electrodes 4 for each line in which a scanning operation is performed. A signal voltage Vd corresponding to the instruction signal from 51 is applied.

Further, the reference driver 8 ″ is configured by using a general-purpose driver, and the reference driver 8 ″ is provided with a decoder 83 and a level shifter 84 as shown in FIG. The decoder 83 extracts an address included in the instruction signal from the image processing unit 51 and discriminates a line on which a scanning operation is performed. Then, the decoder 83 instructs the level shifter 84 to apply the selection voltage as the reference voltage Vr to the corresponding reference electrode 5 so that the scanning operation is performed on the determined line. In addition, a plurality of (all) reference electrodes 5 are connected to the level shifter 84, and the reference voltage Vr (selection) is applied only to the reference electrodes 5 included in the scanning line according to the operation instruction from the decoder 83. Voltage).

Further, the scanning driver 9 ″ is configured by using a general-purpose driver, and the scanning driver 9 ″ is provided with a decoder 93 and a level shifter 94 as shown in FIG. The decoder 93 extracts an address included in the instruction signal from the image processing unit 51 and determines a line on which a scanning operation is performed. Then, the decoder 93 instructs the level shifter 94 to apply the selection voltage as the scanning voltage Vs to the corresponding scanning electrode 6 so that the scanning operation is performed on the determined line. Further, a plurality of (all) scanning electrodes 6 are connected to the level shifter 94, and the scanning voltage Vs (selection) is applied only to the scanning electrodes 6 included in the line where the scanning operation is performed in accordance with the operation instruction from the decoder 93. Voltage).

Next, specific operation examples of the difference information acquisition unit 54, the scanning time determination unit 55, and the scanning operation determination unit 56 in the image display apparatus 1 of the present embodiment will be mainly described with reference to FIG.

FIG. 24 is a diagram illustrating specific operations of the signal driver, the reference driver, and the scan driver shown in FIG. 19 in two consecutive frames. FIGS. 24 (a) and 24 (b) FIG. 24C is a diagram showing a specific display image of two consecutive frames, and FIG. 24C is a diagram showing a difference image of the two frames.

In FIGS. 24 (a) to 24 (c), the lower left hatching indicates that non-CF colored display, that is, black display is performed, and the lower right hatching indicates CF colored display, for example, red display. Indicates that it will be done. Further, in these black display and red display, the gradation value for each pixel region P included in the image input signal is the minimum value and the maximum value (for example, when performing gradation display of 256 gradations, It is assumed that the gradation values are “0” and “255”. Further, in FIGS. 24A to 24C, it is assumed that the scanning operation for each line is performed along the arrows in the figure.

As shown in FIG. 24A, among the two consecutive frames, the display image F4 of the previous frame is included from the line G to the line H on the display surface and from the pixel region K to the pixel region L. In all the pixel areas P, red display is performed, and in all other pixel areas P, black display is performed. The image input signal data including the gradation value for each pixel area P of the display image F4 is held in the frame buffer 52 in the display control unit 50 ″.

In addition, as shown in FIG. 24B, the display image F5 of the subsequent frame of the two consecutive frames is included in the display surface from line I to line J, and from the pixel region K to the pixel region. In all the pixel areas P up to L, red display is performed, and in all other pixel areas P, black display is performed. The image input signal data including the gradation value for each pixel region P of the display image F5 is held in the frame buffer 52 in the display control unit 50 ″.

Subsequently, the difference information acquisition unit 54 stores the data (tone value) of the image input signal of the display image F4 held in the frame buffer 52 and the image input signal of the display image F5 held in the frame buffer 52. By comparing with data (gradation value), a difference between gradation values in two consecutive frames is obtained for each pixel region P and obtained as difference information. Then, the difference information acquisition unit 54 outputs the acquired difference information to the scanning time determination unit 55.

Thereafter, the scanning time determination unit 55 determines the scanning time in the scanning operation based on the difference information from the difference information acquisition unit 54. Specifically, as shown in FIG. 24C, the scanning time determination unit 53 is included in the difference image F6 of two consecutive frames from the line G to the line I on the display surface, and the pixels In all the pixel regions P from the region K to the pixel region L, it is determined that the red display is changed to the black display based on the difference information (that is, the gradation value difference is 255 (= 255-0)). .

The scanning time determination unit 55 includes difference information (that is, the difference information (that is, the pixel area P from the pixel area K to the pixel area L) included in the difference image F6 from the line H to the line J on the display surface. Based on the difference between the gradation values of −255 (= 0−255), it is determined that the black display is changed to the red display.

Further, the scanning time determination unit 55 does not hatch the pixel area P other than the pixel area P that is changed from red display to black display or changed from black display to red display in the difference image F6 (that is, FIG. 24C is not hatched). Is displayed in the same color as the display image F4 based on the difference information (that is, the difference of the gradation value is 0 = (255-255 or = 0-0)), that is, the display color. Determine that is not changed.

The scanning time determination unit 55 then determines the line from line G to line I that has been determined to be changed from red display to black display, and the line H to line J that has been determined to be changed from black display to red display. In the line, as in the second embodiment, the scanning operation is determined to be performed at the scanning time determined according to the maximum absolute value of the gradation value difference, and the determined scanning time and line are determined. This is notified to the scanning operation determination unit 56. Thereafter, the scanning operation determination unit 56 determines whether or not to perform the scanning operation based on the scanning time and the line determined from the scanning time determination unit 55, and further determines the address of the line determined to perform the scanning operation. The acquired line is output to the image processing unit 51.

On the other hand, the scanning time determination unit 55 determines that the display color is not changed, that is, the line from the first line below the line I to the line H from the first line at the top to the line immediately above the line G. The scanning time is set to a value of “0” up to the line one above and from the line below the line J to the last line at the bottom. That is, the scanning time determination unit 55 does not perform the scanning operation on the line for which it is determined that the display color is not changed, and the reference driver 5 and the scanning driver 9 respectively apply the corresponding reference electrode 5 and scanning electrode 6 to the corresponding line. It is determined to maintain the application of the non-selection voltage without applying the selection voltage. Then, the scanning time determination unit 55 notifies the scanning operation determination unit 56 of the determined scanning time and line. Thereafter, the scanning operation determination unit 56 determines the address of the line on which the scanning operation is not performed based on the scanning time and line determined from the scanning time determination unit 55.

After that, the image processing unit 51 acquires the instruction signals to the signal driver 7 ″, the reference driver 8 ″, and the scanning driver 9 ″ that have been generated based on the image input signal from the outside, by the difference information acquisition unit 54. Correction is performed using the difference information thus obtained and the scanning time determined by the scanning time determination unit 55. Further, the image processing unit 51 determines that the scanning operation from the scanning operation determination unit 56 is performed on each instruction signal described above. The address of the selected line is output to the corresponding signal driver 7 ″, reference driver 8 ″, and scan driver 9 ″. Thus, in the signal driver 7 ″, the reference driver 8 ″, and the scanning driver 9 ″, the display colors of the decoders 76, 83, and 93 are changed based on the address included in the instruction signal from the image processing unit 51. The detected line is notified to the level shifters 77, 84, and 94, respectively.

The level shifters 77, 84, and 94 use the lines from the decoders 76, 83, and 93, respectively, to the corresponding signal electrode 4, reference electrode 5, and scan electrode 6, and the signal voltage Vd and reference voltage. Vr (selection voltage) and scanning voltage Vs (selection voltage) are applied.

In the present embodiment, the signal driver 7 ″, the reference driver 8 ″, and the scanning driver 9 ″ are different from those in the third embodiment in that decoders 76, 83, and 93 are used instead of the shift register. Therefore, the operation time of the shift register in the line where the display color is not changed can be omitted, and the display operation on the display element 10 can be easily speeded up.

With the above configuration, the present embodiment can achieve the same operations and effects as the third embodiment. In the present embodiment, the scanning operation determination unit 56 is provided in the display control unit 50 ″, and the signal driver 7 ″, the reference driver 8 ″, and the scanning driver 9 ″ correspond to the determination result of the scanning operation determination unit 56. The voltage is applied to the signal electrode 4, the reference electrode 5, and the scanning electrode 6, respectively. Thereby, in this embodiment, even when performing gradation display, the display operation can be performed at higher speed.

It should be noted that all of the above embodiments are illustrative and not restrictive. The technical scope of the present invention is defined by the claims, and all modifications within the scope equivalent to the configurations described therein are also included in the technical scope of the present invention.

For example, in the above description, the case where the present invention is applied to an image display apparatus provided with a display unit has been described. However, the present invention is an electric device provided with a display unit that displays information including characters and images. The present invention is not limited in any way. For example, it can be suitably used for a portable information terminal such as a PDA such as an electronic notebook, a display device attached to a personal computer, a television, or the like, or an electronic paper or other electric device including various display units. it can.

In the above description, the case where an electrowetting type display element that moves the polar liquid in accordance with the application of an electric field to the polar liquid has been described. However, the display element of the present invention is not limited to this. It is not limited as long as it is an electric field induction type display element that can change the display color on the display surface side by operating a polar liquid inside the display space using an external electric field. Instead, the present invention can be applied to other types of electric field induction display elements such as an electroosmosis method, an electrophoresis method, and a dielectrophoresis method.

However, when the electrowetting type display element is configured as in the above embodiments, the polar liquid can be moved at a high speed with a low driving voltage. Further, in the electrowetting type display element, the display color is changed according to the movement of the polar liquid, and unlike a liquid crystal display device using a birefringent material such as a liquid crystal layer, it is used for information display. It is also preferable in that a high-luminance display element that is excellent in light utilization efficiency of light from the backlight and external light can be easily configured. Furthermore, since it is not necessary to provide a switching element for each pixel, it is also preferable in that a high-performance matrix driving display element having a simple structure can be configured at low cost.

Further, in the above description, the configuration using the signal electrode, the scan electrode, and the reference electrode, the signal driver (signal voltage application unit), the scan driver (scan voltage application unit), and the reference driver (reference voltage application unit). Explained. However, according to the present invention, a difference information acquisition unit that obtains, as difference information, a difference between gradation values in two consecutive frames by using an image input signal from the outside, and obtains the difference information as a difference information. A scanning time determination unit that determines the scanning time in the scanning operation based on the difference information from the display, and the display control unit uses the difference information from the difference information acquisition unit and the scanning time from the scanning time determination unit, There is no limitation as long as each instruction signal to the signal voltage applying unit and the scanning voltage applying unit is generated and a scanning operation corresponding to the scanning time is performed.

Specifically, a plurality of signal electrodes and a plurality of scanning electrodes are provided in a matrix so as to cross each other, and for each of a plurality of pixel regions provided in units of intersections between the signal electrodes and the scanning electrodes, A switching element such as a thin film transistor (TFT) is installed. Then, the scanning electrode is connected to the gate of the thin film transistor, and the voltage is applied from the scanning voltage application unit. Further, the signal electrode is connected to the source of the thin film transistor and voltage is applied from the signal voltage application unit, and the drain of the thin film transistor is connected to the pixel electrode provided for each pixel region to supply the voltage from the signal electrode. In this way, the polar liquid is moved.

Further, in the case of such a configuration, as in the fourth embodiment, the display control is performed on the scanning operation determining unit that determines whether or not to perform the scanning operation based on the scanning time from the scanning time determining unit. The provision in the unit is preferable in that the display operation can be performed at a higher speed even when gradation display is performed.

However, in the case where the reference electrode and the reference driver (reference voltage application unit) are provided as in the above embodiments, the display operation is performed even when gradation display is performed without providing a switching element for each pixel region. This is preferable in that a matrix-driven display element capable of performing the above operation at high speed can be configured.

In the above description, the case where a transmissive display element including a backlight is configured has been described. However, the present invention is not limited to this, and a reflective type having a light reflecting portion such as a diffuse reflector. In addition, the present invention can also be applied to a transflective display element in which the light reflecting portion and the backlight are used in combination.

In the above description, the case where an aqueous solution of potassium chloride is used as a polar liquid has been described, but the polar liquid of the present invention is not limited to this. Specifically, polar liquids include zinc chloride, potassium hydroxide, sodium hydroxide, alkali metal hydroxide, zinc oxide, sodium chloride, lithium salt, phosphoric acid, alkali metal carbonate, oxygen ion conductivity. Those containing an electrolyte such as ceramics can be used. In addition to water, organic solvents such as alcohol, acetone, formamide, and ethylene glycol can also be used as the solvent. Furthermore, the polar liquid of the present invention includes an ionic liquid containing a cation such as pyridine, alicyclic amine, or aliphatic amine, and an anion such as fluoride such as fluoride ion or triflate ( Room temperature molten salt) can also be used.

The polar liquid of the present invention includes a conductive liquid having conductivity and a liquid having a high dielectric constant having a specific dielectric constant of a predetermined value or higher, preferably 15 or higher.

However, as in each of the above embodiments, the use of an aqueous solution in which a predetermined electrolyte is dissolved in a polar liquid is superior in handleability and can easily constitute a display element that is easy to manufacture. Is preferable.

In the above description, the case where nonpolar oil is used has been described. However, the present invention is not limited to this, and any insulating fluid that does not mix with polar liquid may be used. Air may be used. Moreover, silicone oil, aliphatic hydrocarbons, etc. can be used as oil. The insulating fluid of the present invention includes a fluid having a relative dielectric constant of not more than a predetermined value, preferably not more than 5.

However, as in each of the above-described embodiments, the use of nonpolar oil that is not compatible with polar liquid is more polar in the nonpolar oil than when air and polar liquid are used. It is preferable in that the liquid droplets can be moved more easily, the polar liquid can be moved at high speed, and the display color can be switched at high speed.

In the above description, the case where the signal electrode, the reference electrode, and the scanning electrode are provided on the lower substrate (second substrate) side has been described. However, in the present invention, the scanning electrode and the reference electrode are connected to the first and second electrodes in a state in which the signal electrode is disposed inside the display space so as to be in contact with the polar liquid and electrically insulated from each other. What is necessary is just to provide in the one side of a 2nd board | substrate. Specifically, for example, the signal electrode may be provided in the middle portion of the first and second substrates, and the reference electrode and the scan electrode may be provided on the first substrate side.

Further, in the above description, the case where the reference electrode and the scan electrode are respectively installed on the effective display area side and the non-effective display area side has been described, but the present invention is not limited to this, and the reference electrode and the scan electrode May be installed on the non-effective display area side and the effective display area side, respectively.

In the above description, the case where the reference electrode and the scanning electrode are provided on the display surface side surface of the lower substrate (second substrate) has been described. However, the present invention is not limited to this, and the insulating material It is also possible to use a reference electrode and a scan electrode embedded in the second substrate. In such a configuration, the second substrate can be used as a dielectric layer, and the installation of the dielectric layer can be omitted. Furthermore, the signal electrode may be directly provided on the first and second substrates also serving as the dielectric layer, and the signal electrode may be installed inside the display space.

Further, in the above description, the case where the reference electrode and the scan electrode are configured using a transparent electrode material has been described, but the present invention is installed so as to face the effective display area of the pixel among the reference electrode and the scan electrode. It is sufficient that only one of the electrodes is made of a transparent electrode material, and an opaque electrode material such as aluminum, silver, chromium, or other metal can be used for the other electrode that is not opposed to the effective display area. .

In the above description, the case where the belt-like reference electrode and the scan electrode are used has been described. However, the shapes of the reference electrode and the scan electrode of the present invention are not limited to this. For example, in a reflective display element in which the use efficiency of light used for information display is lower than that of a transmissive type, the shape may be such that light loss such as a line shape or a net shape hardly occurs.

In the above description, the case where a linear wiring is used for the signal electrode has been described. However, the signal electrode of the present invention is not limited to this, and wiring formed in other shapes such as a mesh wiring may also be used. Can be used.

In the above description, the case where the pixels of each color of RGB are provided on the display surface side using the polar liquid colored in black and the color filter layer is described, but the present invention is not limited to this. Alternatively, it is only necessary that the plurality of pixel regions are provided in accordance with a plurality of colors capable of full color display on the display surface side. Specifically, a plurality of polar liquids colored in RGB, cyan (C), magenta (M), yellow (Y), CMY, or RGBYC can be used.

In the above description, the color filter layer is formed on the non-display surface side of the upper substrate (first substrate). However, the present invention is not limited to this, and the first substrate A color filter layer can be provided on the display surface side of the substrate or on the lower substrate (second substrate) side. Thus, the case where the color filter layer is used is preferable in that a display element which is easy to manufacture can be easily configured as compared with the case where a plurality of colors of polar liquids are prepared. In addition, the color filter part (opening part) and the black matrix part (light-shielding film) included in the color filter layer appropriately and reliably provide an effective display area and an ineffective display area with respect to the display space. It is also preferable in that it can be set.

The present invention is useful for a display element capable of performing a display operation at high speed even when gradation display is performed, and an electric device using the display element.

1 Image display device (electric equipment)
2 Upper substrate (first substrate)
3 Lower substrate (second substrate)
4 Signal electrode 5 Reference electrode 6 Scan electrode 7, 7 ', 7 "Signal driver (signal voltage application unit)
8, 8 "reference driver (reference voltage application unit)
9, 9 "scan driver (scan voltage application unit)
DESCRIPTION OF SYMBOLS 10 Display element 11 Color filter layer 11r, 11g, 11b Color filter part (opening part)
11s Black matrix (light shielding film)
13 Dielectric layer 14, 14a, 14b Rib (partition wall)
16 Polar liquid 17 Oil (insulating fluid)
50, 50 ', 50 "display control unit 52 frame buffer (storage medium, memory)
53, 53 ′, 55 Scanning time determination unit 54 Difference information acquisition unit 56 Scanning operation determination unit 71 Difference information acquisition unit 71a Frame memory (memory)
S display space P pixel area P1 effective display area P2 non-effective display area F1, F2, F4, F5 (two consecutive images) (display images)
F3, F6 Difference image

Claims (15)

A second substrate provided on the non-display surface side of the first substrate so that a predetermined display space is formed between the first substrate provided on the display surface side and the first substrate. The effective display area and the ineffective display area that are set with respect to the display space, and the display space, and are movably enclosed in the effective display area side or the ineffective display area side within the display space. A display element configured to change a display color on the display surface side by moving the polar liquid.
A plurality of signal electrodes disposed in the display space so as to be in contact with the polar liquid and provided along a predetermined arrangement direction;
Provided on one side of the first and second substrates in a state of being electrically insulated from the polar liquid so as to be installed on one side of the effective display area side and the non-effective display area side. And a plurality of scanning electrodes provided to intersect with the plurality of signal electrodes,
A plurality of pixel regions provided in a unit of intersection between the signal electrode and the scanning electrode;
A display control unit that controls each drive of the signal electrode and the scanning electrode so that a scanning operation along a predetermined scanning direction is performed based on an image input signal from the outside;
Connected to the plurality of signal electrodes and the display control unit, and in accordance with an instruction signal from the display control unit, for each of the plurality of signal electrodes, a predetermined value corresponding to information displayed on the display surface side A signal voltage application unit for applying a signal voltage within a voltage range;
Connected to the plurality of scan electrodes and the display control unit, and allows the polar liquid to move inside the display space in accordance with the signal voltage with respect to the plurality of scan electrodes. A scanning voltage applying unit that applies one of a selection voltage and a non-selection voltage that prevents the polar liquid from moving inside the display space;
A difference information acquisition unit that obtains a difference between gradation values in two consecutive frames for each pixel area using an image input signal from the outside, and acquires the difference information;
Based on the difference information from the difference information acquisition unit, a scanning time determination unit for determining a scanning time in the scanning operation is provided,
The display control unit generates each instruction signal to the signal voltage application unit and the scanning voltage application unit using the difference information from the difference information acquisition unit and the scanning time from the scanning time determination unit, To perform a scanning operation according to the scanning time,
A display element characterized by the above. The display control unit is provided with a scanning operation determining unit that determines whether to perform a scanning operation based on the scanning time from the scanning time determining unit,
The display element according to claim 1, wherein the signal voltage application unit and the scanning voltage application unit apply voltage to the signal electrode and the scanning electrode, respectively, according to a determination result of the scanning operation determination unit. The first and second substrates are electrically insulated from the polar liquid and the scan electrode so as to be installed on the other side of the effective display area side and the non-effective display area side. A plurality of reference electrodes provided on one side and provided to intersect with the plurality of signal electrodes;
The polar liquid is connected to the plurality of reference electrodes and the display control unit and allows the polar liquid to move in the display space according to the signal voltage with respect to the plurality of reference electrodes. A reference voltage applying unit that applies one voltage of a selection voltage and a non-selection voltage that prevents the polar liquid from moving inside the display space;
The display control unit performs drive control of the signal electrode, the scan electrode, and the reference electrode so that a scanning operation along a predetermined scanning direction is performed based on an external image input signal. ,
The display control unit uses the difference information from the difference information acquisition unit and the scanning time from the scanning time determination unit, to each of the signal voltage application unit, the scanning voltage application unit, and the reference voltage application unit The display element according to claim 1, wherein an instruction signal is generated and a scanning operation corresponding to the scanning time is performed. The display control unit is provided with a scanning operation determining unit that determines whether to perform a scanning operation based on the scanning time from the scanning time determining unit,
The signal voltage application unit, the scan voltage application unit, and the reference voltage application unit apply voltages to the signal electrode, the scan electrode, and the reference electrode, respectively, according to the determination result of the scanning operation determination unit. The display element according to claim 3 which performs. The display element according to claim 3, wherein a dielectric layer is laminated on the surfaces of the reference electrode and the scan electrode. The scanning time determination unit determines a scanning time in the scanning operation according to a maximum absolute value of a difference between gradation values included in difference information from the difference information acquisition unit. The display element according to any one of the above. When the display control unit determines that the difference value of the gradation value in two consecutive frames includes a value of 0 in a plurality of pixel regions that are symmetrical with respect to one scanning operation, the difference 7. The display element according to claim 1, wherein an intermediate voltage in the middle of the predetermined voltage range is applied to a signal electrode corresponding to a pixel region having a value of 0. The display element according to any one of claims 1 to 7, further comprising a storage medium for holding data of an image input signal of the last frame in the previous display operation. The display element according to any one of claims 1 to 8, wherein the difference information acquisition unit uses a memory capable of storing image input signal data for at least one frame. The display element according to any one of claims 1 to 9, wherein the difference information acquisition unit is provided in the display control unit. 11. The rib according to claim 1, wherein a rib that divides the inside of the display space is provided on at least one side of the first and second substrates according to each of the plurality of pixel regions. The display element as described. The display element according to claim 1, wherein the plurality of pixel regions are provided in accordance with a plurality of colors capable of full color display on the display surface side. The display element according to any one of claims 1 to 12, wherein an insulating fluid that does not mix with the polar liquid is sealed in the display space so as to be movable in the display space. The ineffective display area is set by a light shielding film provided on one side of the first and second substrates,
The display element according to any one of claims 1 to 13, wherein the effective display area is set by an opening formed in the light shielding film. An electrical device having a display unit for displaying information including characters and images,
15. An electric device using the display element according to claim 1 for the display portion.

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