TWI470334B - Light sensitive display apparatus and operating method thereof - Google Patents

Description

Photosensitive display device and method of operating same

The present invention relates to a display device and a method of operating the same, and more particularly to a photosensitive display device and a method of operating the same.

With the development of electronics and display technology, a variety of different types of display devices have been widely used in various fields, including computers, mobile phones or tablet devices. Display devices with sensing capabilities and no need to use keyboard input information, such as touch panels, are popular among consumers and become mainstream consumers' electronic products.

Traditional display devices with sensing capabilities are mostly touch panels. However, the touch panel needs to detect the touch point, which is a defect that is easy to interfere or poorly positioned. When the touch panel is applied to a display device with a writing function, such as an electronic blackboard or an electronic paper device, the touch panel cannot provide contrast such as a conventional blackboard or paper, and the screen cannot be permanently saved. . In addition, if the touch panel is used under a long time display, for example, in a school, it may cause waste of energy.

In view of this, there is a need to find other practices regarding a display device having a writing function.

One aspect of the present invention provides a photosensitive display device for receiving external light to change its display state, which can be applied to a writing function. Display device, such as an electronic blackboard or an electronic paper device.

According to an embodiment of the invention, a photosensitive display device includes a display panel, a plurality of data lines, a plurality of gate lines, a data driving circuit, and a gate driving circuit. The display panel includes a plurality of pixels. The data line is connected to the pixel. The gate line is connected to the pixel. The data driving circuit is connected to the data line for transmitting the first data voltage to the pixels in the writing state, and in the erased state, transmitting the second data voltage to the pixels through the data line. The gate driving circuit is connected to the gate line for transmitting the first gate voltage to the pixels through the gate line in the writing state, and providing the second gate through the gate line in the erase state The voltage is given to the pixels. In the write state, the pixels illuminated by the light in the pixels are switched to or remain in the first display state, and in the erased state, the pixels illuminated by the light in the pixels are switched to or remain the second. Display state.

According to an embodiment of the present invention, in the writing state, after the pixel illuminated by the light is switched to or maintained in the first display state, the gate driving circuit transmits the pulse pulse to the pixels through the gate line. To preserve the first display state of the pixel illuminated by the light.

According to an embodiment of the invention, each of the pixels comprises a bistable metal oxide transistor connected to each other and a display unit, each display unit having a first display state and a second display state. In the write state, the bistable metal oxide transistor illuminated by the light is switched to or remains at the first steady state and is turned on by the first gate voltage to cause the bistable metal oxide to be connected to the conduction. The display unit of the transistor receives the first data voltage, further switches the display unit to the first display state, and when the display unit switches to the first display state, the bistable metal oxide transistor receives the voltage pulse wave Switch to or remain at the second steady state and turn off.

According to an embodiment of the present invention, in the erased state, after the pixel illuminated by the light is switched to or maintained in the second display state, the gate driving circuit transmits the pulse pulse to the pixels through the gate line. To save the second display state of the pixel illuminated by the light.

According to an embodiment of the invention, each of the pixels comprises a bistable metal oxide transistor connected to each other and a display unit, each display unit having a first display state and a second display state. In the erased state, the bistable metal oxide transistor illuminated by the light is switched to or remains at the first steady state and is turned on by the second gate voltage to cause the bistable metal oxide to be connected to the conduction. The display unit of the transistor receives the second data voltage, further switches the display unit to the second display state, and when the display unit switches to the second display state, the bistable metal oxide transistor receives the voltage pulse and switches to or remains It is the second steady state and is cut off.

According to an embodiment of the invention, the display panel is a bistable electrophoretic display panel.

One aspect of the present invention is to provide a method of operating a photosensitive display device, wherein the photosensitive display device includes a display panel including a plurality of pixels. According to an embodiment of the invention, the method of operation comprises the following steps.

In the write state, the first data voltage and the first gate voltage are supplied to the pixels, and the pixels illuminated by the light are switched to or remain in the first display state.

In the erased state, the second data voltage and the second gate voltage are supplied to the pixels, and the pixels illuminated by the light are switched to or remain as the second display. status.

According to an embodiment of the invention, the step in a write state further comprises the following steps. A voltage pulse is provided to the pixels to preserve a first display state of the pixel illuminated by the light.

According to an embodiment of the invention, each of the pixels includes a bistable metal oxide transistor connected to each other and a display unit, each display unit having a first display state and a second display state. The step in a write state further includes the following steps. Providing a first data voltage and a first gate voltage to the bistable metal oxide transistor, so that the bistable metal oxide transistor irradiated by the light is switched to or maintained at the first steady state and is blocked by the first gate The voltage is turned on, and the display unit connected to the turned-on bistable metal oxide transistor receives the first data voltage, further switching the display unit to or maintaining the first display state. A voltage pulse is applied to the bistable metal oxide transistor to switch the bistable metal oxide transistor to or remain at a second steady state and to turn off the bistable metal oxide transistor.

According to an embodiment of the invention, the step in an erased state further comprises the following steps. A voltage pulse is supplied to the pixels to preserve a second display state of the pixels illuminated by the light.

According to an embodiment of the invention, each of the pixels includes a bistable metal oxide transistor connected to each other and a display unit, each display unit having a first display state and a second display state. The step in an erased state further includes the following steps. Providing a second data voltage and a second gate voltage to the bistable metal oxide transistor to switch the light-irradiated bistable metal oxide transistor to or remain at a first steady state and be etched by the second gate The voltage is turned on, and the bistable metal oxide transistor connected to the conduction is connected The display unit receives the second data voltage to further switch the display unit to or remain in the second display state. A voltage pulse is applied to the bistable metal oxide transistor to switch the bistable metal oxide transistor to or remain at a second steady state and to turn off the bistable metal oxide transistor.

In summary, an embodiment of the present invention can realize a photosensitive display device. The bistable metal oxide transistor is exposed to light to change the conduction state, so that the display unit can switch the display state during illumination, and further achieve the action of writing or erasing with light. Moreover, the use of the pixel to change the display state when illuminated by the light can avoid the disadvantage that the touch panel is easy to interfere and the positioning is poor. The display panel further utilizes the bistable display panel to make the photosensitive display device have permanent storage and low power consumption.

The spirit and scope of the present disclosure will be apparent from the following description of the preferred embodiments of the present disclosure. Modifications do not depart from the spirit and scope of the disclosure.

As used herein, "connected", if not specified in the specification, may be a direct connection or an indirect connection, that is, one end is connected to the other end, with or without an intermediary.

As used herein, "first source/drain" and "second source/drain" mean the source or drain of the transistor, when the "first source/drain" is the source "second source" / Bungee is the bungee, and when the "first source / bungee" is the bungee, the "second source / bungee" is the source.

An aspect of the present invention is to provide a photosensitive display device, which can Writing or erasing with light is a display device that can be applied to a writing function, such as an electronic blackboard or an electronic paper device.

1 is a schematic view of a photosensitive display device 100 in accordance with an embodiment of the present invention. As shown in FIG. 1, the photosensitive display device 100 includes a display panel 110, a plurality of data lines 130, a plurality of gate lines 140, a data driving circuit 150, and a gate driving circuit 160. In this embodiment, the display panel 110 can be a bistable electrophoretic display panel, but is not limited thereto.

Structurally, the display panel 110 includes a plurality of pixels 120, the data line 130 is connected to the pixel 120, the gate line 140 is connected to the pixel 120, the data driving circuit 150 is connected to the data line 130, and the gate driving circuit 160 is connected to the gate line 140. It should be understood that the data driving circuit 150 and the gate driving circuit 160 can be implemented by electronic components and circuits, which can also be different electronic chips, or integrated into a single electronic chip.

In operation, the data driving circuit 150 is configured to supply the first and second data voltages to the pixels 120. The gate driving circuit 160 is configured to supply the first and second gate voltages and the voltage pulse to the pixel 120. Wherein the pixel 120 has a first display state and a second display state, for example, the first display state can be displayed as black, and the second display state can be displayed as white, in addition, in another embodiment, the above 1. The second display state may also be illuminated or not illuminated, or expressed in other display manners, and is not limited to the above examples.

2 is a circuit diagram of a pixel 120 in accordance with an embodiment of the present invention. In the present embodiment, each of the pixels 120 includes a bistable metal oxide transistor 170 and a display unit 180 that are connected to each other.

Structurally, the first source/汲 of the bistable metal oxide transistor 170 The pole is connected to the data line 130, the second source/drain is connected to the first end of the display unit 180, and the gate of the bistable metal oxide transistor 170 is connected to the gate line 140. The second end of the display unit 180 is grounded.

In operation, the bistable metal oxide transistor 170 has a large amount of free electrons due to its metal oxide semiconductor layer being irradiated with light, and its threshold voltage is significantly lowered and switched to another steady state, so that it has illumination. The first first steady state and the second steady state before illumination, and the threshold voltage of the bistable metal oxide transistor 170 in the first steady state is much larger than the bistable metal oxide in the second steady state The threshold voltage of the transistor 170 is low. The display unit 180 has a first display state and a second display state, that is, a first display state and a second display state of the pixel 120.

In practice, the bistable metal oxide transistor 170 may be a metal oxide such as indium gallium zinc oxide or zinc oxide as its semiconductor layer. The display unit 180 can be a simple light-emitting element, such as a light-emitting diode, or a bistable display element, such as an electrophoretic display element or a cholesteric display element. In the present embodiment, the display unit 180 can be realized particularly by a bistable electrophoretic display unit, which has the advantages of high contrast, low reaction time, and low operating voltage.

Figure 3 is a schematic diagram of a write state in accordance with an embodiment of the present invention showing four steps 310-340 in the write state.

In step 310, it is assumed that all of the display units 180 in the display panel 110 at the beginning are in the second display state, for example, white. The data driving circuit 150 transmits the first data voltage to all of the bistable metal oxide transistors 170 through the data line 130, and the gate driving circuit 160 transmits the first gate voltage to all of the bistable metals through the gate line 140. Oxide crystal Body 170. At this time, the first gate voltage does not turn on the bistable metal oxide transistor 170, and thus the first data voltage is not supplied to the display unit 180. The first data voltage is used to switch the display unit 180 from the second display state to the first display state, for example, white is switched to black. For example, the first data voltage can be 20V. The first gate voltage can be used to illuminate the bistable metal oxide transistor 170 after the bistable metal oxide transistor 170 is applied to the first data voltage, but does not conduct bistable metal oxidation prior to illumination. The transistor 170. For example, the first gate voltage can be 0-20V. It should be noted that the voltage values described above can be adjusted according to practical applications, and are not limited to the embodiment.

In step 320, the light emitted by the light pen 10 is written on the display panel 110, and the bistable metal oxide transistor 170 illuminated by the light is switched to or maintained as the first steady state after illumination. When the bistable metal oxide transistor 170 is in the first steady state, it is turned on by the first gate voltage, and the display unit 180 connected to the turned-on bistable metal oxide transistor 170 receives the first data. The voltage further causes the display unit 180 to switch to or remain in the first display state, such as black. The light pen 10 emits light to turn some of the pixels 120 black, that is, as the light pen 10 writes a mark on the display panel 110.

Step 330 is for saving the trace of the write after writing. When the display unit 180 is switched to the first display state, the gate driving circuit 160 can supply a voltage pulse to all of the bistable metal oxide transistors 170 through the gate line 140, so that the bistable metal oxide transistor 170 receives The voltage pulse 332 is switched to or remains at the second steady state, and the bistable metal oxide transistor 170 is turned off and is no longer turned on, thus preserving the pixel 120 illuminated by the light. The first display state. It should be noted that the voltage pulse 332 is used to switch the bistable metal oxide transistor 170 from the first steady state to the second steady state, and the voltage thereof may be, for example, 40V, but is not limited thereto.

Step 340 is a state in which writing is ended, at which time the trace written by the light pen 10 on the display panel 110 has been saved, and the first data voltage or the first gate electrode of the pixel 120 need not be given again.

Figure 4 is a schematic diagram of the erased state in accordance with an embodiment of the present invention showing four steps 410-440 in the erased state.

In step 410, it is assumed that the display unit 180 at the beginning is in the first display state, for example, black, and the remaining display unit 180 is in the second display state, for example, white. The data driving circuit 150 transmits the second data voltage to all the display units 180 through the data line 130, and the gate driving circuit 160 transmits the second gate voltage to all the display units 180 through the gate lines 140. At this time, the second gate voltage does not turn on the bistable metal oxide transistor 170, and thus the second data voltage is not supplied to the display unit 180. The second data voltage is used to switch the display unit 180 from the first display state to the second display state, for example, black is switched to white. For example, the second data voltage can be -20V. The second gate voltage can be used to illuminate the bistable metal oxide transistor 170 after the bistable metal oxide transistor 170 is applied to the second data voltage, but does not conduct bistable metal oxidation prior to illumination. The transistor 170. For example, the first gate voltage can be from 0 to -20V. It should be noted that the voltage values described above can be adjusted according to practical applications, and are not limited to the embodiment.

In step 420, the bistable metal oxide transistor 170 is exposed to light by using a squeegee 20 to emit light onto the display panel 110. Switch to or remain the first steady state after illumination. When the bistable metal oxide transistor 170 is in the first steady state, it is turned on by the second gate voltage, and the display unit 180 connected to the turned-on bistable metal oxide transistor 170 receives the second data. The voltage further causes the display unit 180 to switch or remain in a second display state, such as white. Therefore, the wipe 20 emits light to make the partial pixels 120 white, as the eraser 20 erases the trace on the display panel 110.

Step 430 can save the second display state of the pixel 120 after erasing. When the display unit 180 is switched to the second display state, the gate driving circuit 160 can supply the voltage pulse 432 to all the bistable metal oxide transistors 170 through the gate line 140 to make the bistable metal oxide transistor 170 The voltage pulse is received to switch to or remain at the second steady state, and the bistable metal oxide transistor 170 is turned off and no longer turned on to preserve the second display state of the pixel 120 illuminated by the light. It should be noted that the voltage pulse 432 is used to switch the bistable metal oxide transistor 170 from the first steady state to the second steady state, and the voltage thereof may be, for example, 40V, but is not limited thereto.

Step 440 is to end the erased state, at which time the second display state of the pixel 120 after erasing has been saved, and the second data voltage or the second gate electrode of the pixel 120 need not be given.

The light pen 10 and the wiper 20 mentioned in the above paragraph are light-emitting devices that emit light. The light emission area of the eraser 20 can be larger than the light emission area of the light pen 10 to facilitate erasing, as shown in FIG. It is worth noting that the energy carried by the light emitted by the light pen 10 and the eraser 20 must be capable of exciting the electrons of the metal oxide semiconductor layer. In an embodiment, since the work function of the general metal is above 2.8 eV, the energy carried by the light should be greater than 2.8 eV, ie its wavelength must be less than 443 nm. The light may be a near-ultraviolet light having a wavelength between 300 and 400 nanometers, but the wavelength of the photosensitive display device 100 is not limited, and the wavelength may be determined depending on the actual application.

Moreover, in the present embodiment, since the signals on all of the data lines 130 are the same, the data lines 130 can be connected to each other to simplify the circuit. In addition, the signals on all of the gate lines 140 are also the same, so that the gate lines 140 can also be connected to each other to simplify the circuit. It should be noted that in other embodiments, the signals carried by the data line 130 or the gate line 140 are not necessarily the same, and the data lines 130 or the gate lines 140 are not necessarily connected to each other, so the connection relationship is not This embodiment is limited.

In summary, the photosensitive display device 100 provided by the embodiment of the present invention has a writing state and an erasing state, and the operation method thereof includes the following steps.

(a) In the write state, the data driving circuit 150 transmits the first data voltage to all of the pixels 120 through the data line 130, and the gate driving circuit 160 transmits the first gate voltage to all of the pixels 120 through the gate line 140. The pixel 120 illuminated by the light is switched to or maintained in the first display state. In addition, after the pixel 120 illuminated by the light is switched to or maintained in the first display state, the gate driving circuit 160 supplies a voltage pulse wave to the pixels 120 through the gate line 140, and can store the pixel 120 illuminated by the light. The first display state.

(b) In the erased state, the data driving circuit 150 transmits the second data voltage to all of the pixels 120 through the data line 130, and the gate driving circuit 160 transmits the second gate voltage to all of the pixels 120 through the gate line 140. Switching the pixel 120 illuminated by the light into or holding the second display state. In addition, after the pixel 120 illuminated by the light is switched to or maintained in the second display state, the gate driving circuit 160 supplies a voltage pulse to the pixels 120 through the gate line 140, and can store the pixel 120 illuminated by the light. The second display state.

Through the display device and the method of operating the same as described above, a photosensitive display device having light writing properties and utilizing light for writing or erasing can be realized. The photosensitive display device is different in structure and operation from the conventional touch panel, and does not need to detect the touch position, but can directly change the display state of the pixel by illumination, unlike the conventional touch panel. The complicated configuration, and can also avoid the shortcomings of the touch panel being easy to interfere and poorly positioned. In addition, the photosensitive display device has the characteristics of low energy consumption and permanent image storage, and is advantageous for a display device having a writing function, such as an electronic blackboard or an electronic paper device.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and retouched without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

10‧‧‧ light pen

20‧‧‧Erasing

100‧‧‧Photosensitive display device

110‧‧‧ display panel

120‧‧ ‧ pixels

130‧‧‧Information line

140‧‧ ‧ gate line

150‧‧‧Data Drive Circuit

160‧‧ ‧ gate drive circuit

170‧‧‧Bistable Metal Oxide Transistor

180‧‧‧Display unit

310‧‧‧Steps

320‧‧‧Steps

330‧‧‧Steps

332‧‧‧Voltage pulse

340‧‧‧Steps

410‧‧‧Steps

420‧‧ steps

430‧‧ steps

432‧‧‧Voltage pulse

440‧‧‧Steps

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt;

2 is a circuit diagram of a pixel in accordance with an embodiment of the present invention.

Figure 3 is a diagram of a write state in accordance with an embodiment of the present invention. intention.

Fig. 4 is a schematic view showing the erasing state in accordance with an embodiment of the present invention.

Figure 5 is a schematic view of a light pen and a wiper in accordance with an embodiment of the present invention.

100‧‧‧Photosensitive display device

110‧‧‧ display panel

120‧‧ ‧ pixels

130‧‧‧Information line

140‧‧ ‧ gate line

150‧‧‧Data Drive Circuit

160‧‧ ‧ gate drive circuit

Claims (9)

A photosensitive display device comprises: a display panel comprising a plurality of pixels; a plurality of data lines connecting the pixels; a plurality of gate lines connecting the pixels; and a data driving circuit connecting the data lines Transmitting the data lines to provide the first data voltage to the pixels in a write state, and in an erased state, transmitting the second data voltages to the pixels through the data lines; a gate driving circuit connecting the gate lines for transmitting a first gate voltage to the pixels through the gate lines in the writing state, and in the erased state, transmitting The gate lines are provided with a second gate voltage to the pixels; wherein in the writing state, the pixels illuminated by the light in the pixels are switched to or remain in a first display state, and the pixel The gate driving circuit transmits the voltage pulse to the pixels through the gate lines to save the first display state of the pixel illuminated by the light, and in the erased state, the pixels are received by the light The pixel illuminated Maintained or replaced with a second display state. The photosensitive display device of claim 1, wherein each of the pixels comprises a bistable metal oxide transistor connected to each other and a display unit, each of the display units having the first display state and the a second display state in which the bistable metal oxide is irradiated by light Switching on or maintaining a first steady state, and being turned on by the first gate voltage, causing the display unit connected to the turned-on bistable metal oxide transistor to receive the first data voltage, And further switching the display unit to the first display state, and when the display unit is switched to the first display state, the bistable metal oxide transistors receive the voltage pulse wave and switch to or remain as a first Two steady state and cut off. The photosensitive display device of claim 1, wherein in the erased state, after the pixel illuminated by the light in the pixels is switched to or maintained in the second display state, the gate driving circuit transmits The gate lines provide a voltage pulse to the pixels to preserve the second display state of the pixel illuminated by the light. The photosensitive display device of claim 3, wherein each of the pixels comprises a bistable metal oxide transistor connected to each other and a display unit, each of the display units having the first display state and the a second display state in which the bistable metal oxide transistor illuminated by the light is switched to or maintained at a first steady state and is turned on by the second gate voltage to cause connection The display unit of the bistable metal oxide transistor that is turned on receives the second data voltage, further switches the display unit to the second display state, and when the display unit switches to the second display state, The bistable metal oxide transistors receive the voltage pulse and switch to or remain at a second steady state and are turned off. The photosensitive display device of claim 1, wherein the display panel is a bistable electrophoretic display panel. An operation method for a photosensitive display device, wherein the photosensitive display device comprises a display panel, the display panel comprises a plurality of pixels, and the operation method comprises: providing a first data voltage and a The first gate voltage is applied to the pixels, so that the pixels illuminated by the light in the pixels are switched to or remain in a first display state; in the write state, a voltage pulse is provided to the pixels, And storing the first display state of the pixel illuminated by the light; and in an erased state, providing a second data voltage and a second gate voltage to the pixels, so that the pixels are illuminated by the light The pixel is switched to or remains in a second display state. The method of operating a photosensitive display device according to claim 6, wherein each of the pixels comprises a bistable metal oxide transistor connected to each other and a display unit, each of the display units having the first display a state and the second display state, and wherein the step of the writing state further comprises: providing the first data voltage and the first gate voltage to the bistable metal oxide transistors to The bistable metal oxide transistor illuminated by the light in the steady state metal oxide transistor is switched to or maintained at a first steady state and is turned on by the first gate voltage to cause the pair to be connected to the conduction The display unit of the steady state metal oxide transistor receives the first data a voltage, further switching the display unit to or maintained in the first display state; and providing the voltage pulse to the bistable metal oxide transistors to switch the bistable metal oxide transistors to Or remain at a second steady state and turn off the bistable metal oxide transistors. The method of operating a photosensitive display device according to claim 6, wherein the step of the erasing state further comprises: providing a voltage pulse to the pixels to save the second pixel of the pixel illuminated by the light Display state. The method of operating a photosensitive display device according to claim 8, wherein each of the pixels comprises a bistable metal oxide transistor connected to each other and a display unit, each of the display units having the first display a state and the second display state, and wherein the step of the erasing state further comprises: providing the second data voltage and the second gate voltage to the bistable metal oxide transistors to The bistable metal oxide transistor illuminated by the light in the steady state metal oxide transistor is switched to or maintained at a first steady state and is turned on by the second gate voltage to cause the pair to be connected to the conduction The display unit of the steady state metal oxide transistor receives the second data voltage to further switch the display unit to or remain in the second display state; and provides the voltage pulse wave to the bistable metal oxide a crystal to switch or maintain the bistable metal oxide transistor to a second stable state And turn off the bistable metal oxide transistors.