JP2011022342A - Display device, method of driving the same and electronics device - Google Patents

Abstract

A display device, a driving method thereof, and an electronic apparatus capable of improving low gradation image quality when signal writing is performed in two steps.
A After performing the tone complement writing, when it begins bootstrap operation, is stopped bootstrap operation immediately, the mobility correction is started (T ₆ ~T _8). When the bootstrap operation is started after the mobility correction is completed, the bootstrap operation is immediately stopped and the signal voltage is written (T _{9 to} T ₁₁ ). As described above, the mobility correction is performed before the second signal writing, so that the mobility correction is performed regardless of the value of the second signal voltage V _sig2 .
[Selection] Figure 3

Description

  The present invention relates to a display device that displays an image with a light emitting element arranged for each pixel and a driving method thereof. Moreover, this invention relates to the electronic device provided with the said display apparatus.

  In recent years, in the field of display devices that perform image display, display devices that use current-driven optical elements, such as organic EL (electroluminescence) elements, whose light emission luminance changes according to the value of a flowing current are used as light emitting elements of pixels. Developed and commercialized.

  Unlike a liquid crystal element or the like, the organic EL element is a self-luminous element. Therefore, a display device (organic EL display device) using an organic EL element does not require a light source (backlight), and thus has higher image visibility and lower power consumption than a liquid crystal display device that requires a light source. And the response speed of the element is fast.

  In the organic EL display device, similarly to the liquid crystal display device, there are a simple (passive) matrix method and an active matrix method as its driving method. Although the former has a simple structure, there is a problem that it is difficult to realize a large-sized and high-definition display device. For this reason, active matrix systems are currently being actively developed. In this method, a current flowing in a light emitting element arranged for each pixel is controlled by an active element (generally a TFT (Thin Film Transistor)) in a drive circuit provided for each light emitting element.

  By the way, in general, the current-voltage (IV) characteristics of the organic EL element deteriorate (deteriorate with time) as time elapses. In a pixel circuit that current-drives an organic EL element, when the IV characteristic of the organic EL element changes with time, the current value that flows through the drive transistor changes, so the current value that flows through the organic EL element also changes, and the current value Accordingly, the light emission luminance also changes.

Further, the threshold voltage V _th and the mobility μ of the driving transistor may change with time, or the threshold voltage V _th and the mobility μ may be different for each pixel circuit due to variations in manufacturing processes. When the threshold voltage V _th and the mobility μ of the driving transistor are different for each pixel circuit, the current value flowing through the driving transistor varies for each pixel circuit. Therefore, even if the same voltage is applied to the gate of the driving transistor, the organic EL The light emission luminance of the elements varies, and the uniformity of the screen is lost.

Therefore, in order to keep the light emission luminance of the organic EL element constant, a compensation function for fluctuations in the IV characteristics of the organic EL element and a correction function for fluctuations in the threshold voltage _Vth and mobility μ of the driving transistor are incorporated. Display devices have been developed (see, for example, Patent Documents 1 to 4). These Patent Documents 1 to 4 describe performing μ correction and signal writing at the same time, or performing μ correction in parallel with signal writing during the last period while performing signal writing.

JP 2007-171827 A JP 2007-108381 A JP 2007-133283 A JP 2007-133284 A

  In the past, there has been proposed a method of increasing the video gradation by performing signal writing in two steps after performing threshold correction by applying the driving methods described in Patent Documents 1 to 4. However, in this method, after the first signal writing, the bootstrap occurs until the second signal writing. For this reason, the signal voltage value for the first time cannot be increased, and the mobility correction cannot be sufficiently performed at the time of the first signal writing. Accordingly, when the signal voltage value for the second time is small, the mobility correction cannot be sufficiently performed even in the second signal writing, and there is a problem that the image quality of low gradation is deteriorated. .

  The present invention has been made in view of such problems, and an object of the present invention is to provide a display device, a driving method thereof, and an electronic device capable of improving low gradation image quality when signal writing is performed twice. To provide equipment.

  The display device of the present invention includes a pixel circuit array section, a scanning line driving circuit, and a signal line driving circuit. The pixel circuit array section is arranged in a matrix corresponding to a plurality of scanning lines arranged in rows, a plurality of signal lines arranged in columns, and intersections of the scanning lines and signal lines. A plurality of light emitting elements and a plurality of pixel circuits are included. The signal line driving circuit applies a gradation complementary voltage corresponding to the video signal, a fixed mobility correction voltage, and a signal voltage corresponding to the video signal to each signal line in this order to select a pixel circuit to be selected. To write to. The scanning line driving circuit sequentially applies selection pulses to a plurality of scanning lines to sequentially select a plurality of light emitting elements and a plurality of pixel circuits. The scanning line driving circuit further applies a selection pulse to one scanning line during a period in which the signal line driving circuit applies the mobility correction voltage to the plurality of signal lines.

  An electronic apparatus according to the present invention includes the display device.

The display device driving method of the present invention includes the following two steps.
(A) Step of preparing a display device having the following configuration (B) Using the scanning line driving circuit, the signal line driving circuit applies a mobility correction voltage to a plurality of signal lines within one period. Applying a selection pulse to the scanning line

  A display device using the above driving method includes a pixel circuit array section, a scanning line driving circuit, and a signal line driving circuit. The pixel circuit array section is arranged in a matrix corresponding to a plurality of scanning lines arranged in rows, a plurality of signal lines arranged in columns, and intersections of the scanning lines and signal lines. A plurality of light emitting elements and a plurality of pixel circuits are included. The scanning line driving circuit sequentially applies selection pulses to a plurality of scanning lines to sequentially select a plurality of light emitting elements and a plurality of pixel circuits. The signal line driving circuit applies a gradation complementary voltage corresponding to the video signal, a fixed mobility correction voltage, and a signal voltage corresponding to the video signal to each signal line in this order to select a pixel circuit to be selected. To write to.

  In the display device, the driving method thereof, and the electronic device of the present invention, the selection pulse is applied to one scanning line during the period in which the signal line driving circuit applies the mobility correction voltage to the plurality of signal lines. Thereby, the mobility of the pixel circuit can be corrected regardless of the magnitude of the signal voltage.

  According to the display device, the driving method thereof, and the electronic apparatus of the present invention, the mobility of the pixel circuit can be corrected regardless of the magnitude of the signal voltage. Thereby, when signal writing is performed twice, the image quality of low gradation can be improved.

It is a block diagram showing an example of the display apparatus which concerns on one embodiment of this invention. FIG. 2 is a configuration diagram illustrating an example of an internal configuration of a pixel circuit array unit in FIG. 1. It is a wave form diagram for demonstrating an example of the line operation | movement of the display apparatus of FIG. It is a wave form diagram for demonstrating an example of operation | movement of the display apparatus which concerns on a comparative example. It is a top view showing schematic structure of the module containing the display apparatus of the said embodiment. It is a perspective view showing the external appearance of the application example 1 of the display apparatus of the said embodiment. (A) is a perspective view showing the external appearance seen from the front side of the application example 2, (B) is a perspective view showing the external appearance seen from the back side. 12 is a perspective view illustrating an appearance of application example 3. FIG. 14 is a perspective view illustrating an appearance of application example 4. FIG. (A) is a front view of the application example 5 in an open state, (B) is a side view thereof, (C) is a front view in a closed state, (D) is a left side view, and (E) is a right side view, (F) is a top view and (G) is a bottom view.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings. The description will be given in the following order.

1. Embodiment
1.1 Schematic configuration of display device
1.2 Operation of display device
1.3 Actions and effects Modules and application examples

<1. Embodiment>
(1.1 Schematic configuration of display device)
FIG. 1 shows a schematic configuration of a display device 1 according to an embodiment of the present invention. The display device 1 includes a display panel 10 and a drive circuit 20. The display panel 10 includes, for example, a pixel circuit array unit 13 in which a plurality of organic EL elements 11R, 11G, and 11B (light emitting elements) are arranged in a matrix. In the present embodiment, for example, three organic EL elements 11R, 11G, and 11B adjacent to each other constitute one pixel 12. Hereinafter, the organic EL element 11 is appropriately used as a general term for the organic EL elements 11R, 11G, and 11B. The drive circuit 20 drives the pixel circuit array unit 13, and includes, for example, a video signal processing circuit 21, a timing generation circuit 22, a signal line drive circuit 23, a scanning line drive circuit 24, and a power supply line drive circuit 25. ing.

[Pixel circuit array section]
FIG. 2 illustrates an example of a circuit configuration of the pixel circuit array unit 13. The pixel circuit array unit 13 is formed in the display area of the display panel 10. For example, as illustrated in FIGS. 1 and 2, the pixel circuit array unit 13 includes a plurality of scanning lines WSL arranged in rows, a plurality of signal lines DTL arranged in columns, and scanning lines WSL. And a plurality of power supply lines PSL arranged in rows. A plurality of organic EL elements 11 and pixel circuits 14 are arranged in a matrix (two-dimensional arrangement) corresponding to the intersections of the scanning lines WSL and the signal lines DTL. The pixel circuit 14 is configured by, for example, a drive transistor Tr ₁ , a write transistor Tr _2, and a storage capacitor C _s , and has a circuit configuration of 2Tr1C. The drive transistor Tr ₁ and the write transistor Tr ₂ are formed by, for example, n-channel MOS type thin film transistors (TFTs). Note that the type of TFT is not particularly limited, and may be, for example, an inverted staggered structure (so-called bottom gate type) or a staggered structure (top gate type). Further, the drive transistor Tr ₁ or the write transistor Tr ₂ may be a p-channel MOS type TFT.

In the pixel circuit array section 13, the signal line DTL, the output terminal of the signal line drive circuit 23 (not shown) is connected to the drain electrode of the writing transistor Tr ₂ (not shown). Each scanning line WSL is the output terminal of the scanning line drive circuit 24 (not shown) is connected to the gate electrode of the writing transistor Tr ₂ (not shown). Each power line PSL, the output terminal of the power source line drive circuit 25 (not shown) is connected to the drain electrode of the driving transistor Tr ₁ (not shown). The source electrode (not shown) of the write transistor Tr ₂ is connected to the gate electrode (not shown) of the drive transistor Tr ₁ and one end of the storage capacitor C _s . The source electrode (not shown) of the drive transistor Tr ₁ and the other end of the storage capacitor C _s are connected to the anode electrode (not shown) of the organic EL element 11. A cathode electrode (not shown) of the organic EL element 11 is connected to the ground line GND, for example. The cathode electrode is used as a common electrode for each organic EL element 11, and is formed continuously over the entire display region of the display panel 10, for example, and has a flat plate shape.

[Drive circuit]
Next, each circuit in the drive circuit 20 provided around the pixel circuit array unit 13 will be described with reference to FIG. The video signal processing circuit 21 performs predetermined correction on the digital video signal 20 </ b> A input from the outside and outputs the corrected video signal to the signal line driving circuit 23. Examples of the predetermined correction include gamma correction and overdrive correction. The timing generation circuit 22 controls the signal line driving circuit 23, the scanning line driving circuit 24, and the power supply line driving circuit 25 to operate in conjunction with each other. The timing generation circuit 22 outputs a control signal 22A to these circuits, for example, in response to (in synchronization with) a synchronization signal 20B input from the outside.

The signal line driving circuit 23 applies an analog video signal corresponding to the video signal 20A input from the video signal processing circuit 21 to each signal line DTL in response to (in synchronization with) the input of the control signal 22A. An analog video signal or a signal corresponding thereto is written to the pixel circuit 14 to be selected. Specifically, the signal line driving circuit 23 outputs the gradation complementary voltage V _sig1 corresponding to the video signal 20A, the fixed mobility correction voltage V _ofs2, and the signal voltage V _sig2 corresponding to the video signal in this order. By applying to each signal line DTL, writing to the pixel circuit 14 to be selected is performed. Note that writing refers to applying a predetermined voltage between the gate and source of the driving transistor Tr ₁ . For example, the signal line driving circuit 23 _generates a signal voltage V _sig2 and a gradation complementary voltage V _sig1, and a voltage V _ofs1 and a mobility correction voltage V _ofs2 applied to the gate of the driving transistor Tr ₁ when the organic EL element 11 is extinguished. It is possible to output. Here, the gradation complementary voltage V _sig1 is in the signal voltage V _sig2 a predetermined relationship, for example, has a signal voltage V _sig2 following voltage values. The voltage V _ofs1 is a voltage (V _el) obtained by adding (V _ofs1 −V _th ) the threshold voltage V _el of the organic EL element 11 and the cathode voltage V _ca when the threshold voltage of the driving transistor Tr ₁ is V _th. It is set to be a voltage value (constant value) lower than + V _ca ). The voltage V _ofs2 is a voltage used when correcting the mobility of the drive transistor Tr ₁ . The voltage V _ofs2 is _expressed as (V _ofs1 −V _th + ΔV ₁ + ΔV ₂ ) as voltage (V _el + V _ca ) where ΔV _{1 is} the increase in source potential in gradation complementary writing and ΔV ₂ is the increase in source potential in mobility correction. Is set to be a lower voltage value (a constant value).

The scanning line drive circuit 24 sequentially selects the plurality of organic EL elements 11 and the plurality of pixel circuits 14 by sequentially applying selection pulses to the plurality of scanning lines WSL in response to (in synchronization with) the input of the control signal 22A. To do. Scanning line drive circuit 24, for example, it is possible to output a voltage V _on is applied when turning on the writing transistor Tr _2, and a voltage V _off to be applied when turning off the write transistor Tr ₂ . Here, the voltage V _on is a value (a constant value) equal to or higher than the on-voltage of the write transistor Tr ₂ . The voltage V _off is a value (constant value) lower than the ON voltage of the write transistor Tr ₂ .

The power supply line drive circuit 25 controls the light emission and quenching of the organic EL element 11 by sequentially applying control pulses to the plurality of power supply lines PSL in response to (in synchronization with) the input of the control signal 22A. Power line drive circuit 25, for example, a voltage V _ccH applied when supplying a current to the driving transistor Tr _1, and it is possible to output a voltage V _ccL applied when no current is supplied to the drive transistor Tr ₁ It has become. Here, the voltage V _ccL is a voltage value (constant value) lower than a voltage (V _el + V _ca ) obtained by adding the threshold voltage V _el of the organic EL element 11 and the voltage V _ca of the cathode of the organic EL element 11. It is. V _ccH is a voltage value (constant value) equal to or higher than the voltage (V _el + V _ca ).

(1.2 Operation of display device)
FIG. 3 shows an example of various waveforms when the display device 1 is driven. FIG 3 (A) ~ (C) , V ofs1 to the signal line _{DTL, V sig1, V ofs2,} V sig2 are periodically applied, V _ccL, V _ccH is applied at a predetermined timing to the power supply line PSL The state in which V _on and V _off are applied to the scanning line WSL at a predetermined timing is shown. 3D and 3E, the gate voltage V _g and the source voltage V _{s of} the drive transistor Tr ₁ change from moment to moment in response to voltage application to the signal line DTL, the scanning line WSL, and the power supply line PSL. Is shown.

[V _th correction preparation period]
First, preparation for V _th correction is performed. Specifically, the power supply line drive circuit 25 lowers the voltage of the power line PSL from V _ccH the V _ccL (T _1). Then, the source voltage V _s becomes V _ccL , the organic EL element 11 is extinguished, and the gate voltage V _g becomes (V _ccL + V _gs0 ) when V _gs at the time of light emission is V _gs0 . Next, while the voltage of the signal line DTL is V _ofs1 and the voltage of the power supply line PSL is V _ccL , the scanning line driving circuit 24 changes the voltage of the scanning line WSL from V _off to V _on . increase.

[First V _th correction period]
Next, V _th is corrected. Specifically, while the voltage of the signal line DTL is V _ofs1, power line drive circuit 25 raises the voltage of the power supply line PSL from V _ccL the V _ccH (T _2). Then, a current I _d flows between the drain and source of the driving transistor Tr ₁ and the source voltage V _s rises. Thereafter, before the signal line driving circuit 23 switches the voltage of the signal line DTL from V _ofs1 to V _sig1 , the scanning line driving circuit 24 reduces the voltage of the scanning line WSL from V _on to V _off (T ₃ ). Then, the gate of the drive transistor Tr ₁ becomes floating, and the correction of V _th is temporarily stopped.

[First stop period]
During the period in which the V _th correction is paused, the voltage of the signal line DTL is sampled in another row (pixel) different from the row (pixel) on which the previous V _th correction has been performed. In the case V _th correction is insufficient, i.e., the gate of the drive transistor Tr ₁ - when the potential difference V _gs between the source is larger than the threshold voltage V _th of the drive transistor Tr ₁ is as follows. Even during the V _th correction pause period, the current I _d flows between the drain and source of the drive transistor Tr ₁ in the row (pixel) in which the previous V _th correction has been performed, the source voltage V _s rises, and the storage capacitor C Coupling through _s also increases the gate voltage V _g .

[Second V _th correction period]
After the V _th correction pause period ends, the V _th correction is performed again. Specifically, when the voltage of the signal line DTL is V _ofs1 and V _th correction is possible, the scanning line driving circuit 24 increases the voltage of the scanning line WSL from V _off to V _on (T ₄ ) The gate of the driving transistor Tr ₁ is connected to the signal line DTL. At this time, when the source voltage V _s is lower than (V _ofs1 −V _th ) (when V _th correction is not yet completed), the drive transistor Tr ₁ is cut off (the potential difference V _gs is V _th). Until the current I _d flows between the drain and source of the drive transistor Tr ₁ . As a result, the holding capacitor C _s is charged to V _th, the potential difference V _gs becomes V _th. Thereafter, before the signal line driving circuit 23 switches the voltage of the signal line DTL from V _ofs1 to V _sig1 , the scanning line driving circuit 24 lowers the voltage of the scanning line WSL from V _on to V _off (T ₅ ). Then, since the gate of the drive transistor Tr ₁ becomes floating, the potential difference V _gs can be maintained at V _th regardless of the voltage level of the signal line DTL. In this way, by setting the potential difference V _gs to V _{th, even} when the threshold voltage V _th of the drive transistor Tr ₁ varies for each pixel circuit 14, the emission luminance of the organic EL element 11 varies. Can be eliminated.

[Second pause]
Thereafter, during the rest period V _th correction, the signal line drive circuit 23 changes the voltage of the signal line DTL from V _ofs to V _sig1.

[Gradation complementary writing period]
After the _Vth correction pause period ends, gradation complementary writing is performed. Specifically, while the voltage of the signal line DTL is V _sig1 , the scanning line driving circuit 24 increases the voltage of the scanning line WSL from V _off to V _on (T ₆ ), and the gate of the driving transistor Tr ₁ Is connected to the signal line DTL. Then, the gate voltage of the drive transistor Tr ₁ becomes V _sig1 . At this time, the anode voltage of the organic EL element 11 is still lower than the voltage (V _el + V _ca ) of the threshold voltage V _el and the cathode voltage V _ca of the organic EL element 11 at this stage, and the organic EL element 11 is cut. Is off. Therefore, the current I _d flows through the element capacitance (not shown) of the organic EL element 11 and the element capacitance is charged. Therefore, the source voltage V _s increases by ΔV ₁ , and the potential difference V _gs eventually becomes V _sig1 + V _th −. ΔV ₁ is obtained. In this way, mobility correction is performed simultaneously with gradation complementary writing.

[First bootstrap period]
Next, the scanning line driving circuit 24 lowers the voltage of the scanning line WSL from V _on to V _off (T ₇ ). Then, the gate of the drive transistor Tr ₁ becomes floating, the gate of the drive transistor Tr ₁ - a voltage V _gs between the source while maintaining constant, the drain of the drive transistor Tr ₁ - current I _d flows between the source. As a result, the source voltage V _s increases, and the gate of the drive transistor Tr ₁ also increases in conjunction with it.

[Mobility correction period]
Once started bootstrap operation, immediately, the signal line drive circuit 23 changes the voltage of the signal line DTL from V _sig1 to V _ofs2. Subsequently, the scanning line driving circuit 24 raises the voltage of the scanning line WSL from V _off to V _on (T ₈ ), and connects the gate of the driving transistor Tr ₁ to the signal line DTL. Then, the gate voltage of the drive transistor Tr ₁ becomes V _{ofs 2} and the bootstrap operation stops. At this time, the anode voltage of the organic EL element 11 is still smaller than the voltage (V _el + V _ca ) at this stage, and the organic EL element 11 is cut off. Therefore, the current I _d flows through the element capacitance (not shown) of the organic EL element 11 and the element capacitance is charged. Therefore, the source voltage V _s increases by ΔV ₂ and the potential difference V _gs eventually becomes V _ofs 2 + V _th −. ΔV ₁ −ΔV ₂ . In this way, mobility correction is performed separately (independently) from the writing of the signal voltage V _sig2 .

[Second bootstrap period]
Next, the scanning line driving circuit 24 lowers the voltage of the scanning line WSL from V _on to V _off (T ₉ ). Then, the gate of the drive transistor Tr ₁ becomes floating, the gate of the drive transistor Tr ₁ - a voltage V _gs between the source while maintaining constant, the drain of the drive transistor Tr ₁ - current I _d flows between the source. As a result, the source voltage V _s increases, and the gate of the drive transistor Tr ₁ also increases in conjunction with it.

[Writing period]
Once started bootstrap operation, immediately, the signal line drive circuit 23 changes the voltage of the signal line DTL from V _ofs2 to V _sig2. Subsequently, the scanning line driving circuit 24 raises the voltage of the scanning line WSL from V _off to V _on (T ₁₀ ), and connects the gate of the driving transistor Tr ₁ to the signal line DTL. Then, the gate voltage of the drive transistor Tr ₁ becomes V _sig2 and the bootstrap operation stops. At this time, the anode voltage of the organic EL element 11 is smaller than the voltage (V _el + V _ca ) even at this stage, and the organic EL element 11 is cut off. Therefore, the current I _d flows through the element capacitance (not shown) of the organic EL element 11 and the element capacitance is charged. Therefore, the source voltage V _s rises by ΔV ₃ and the potential difference V _gs eventually becomes V _sig2 + V _th −. ΔV ₁ −ΔV ₂ −ΔV ₃ . In this way, the signal voltage V _sig2 is written.

[Flash duration]
Next, the scanning line driving circuit 24 lowers the voltage of the scanning line WSL from V _on to V _off (T ₁₁ ). Then, the gate of the drive transistor Tr ₁ becomes floating, the gate of the drive transistor Tr ₁ - a voltage V _gs between the source while maintaining constant, the drain of the drive transistor Tr ₁ - current I _d flows between the source. As a result, the source voltage V _s rises, and the gate of the drive transistor Tr ₁ rises in conjunction with it, and the organic EL element 11 emits light with a desired luminance.

[repetition]
Next, after a predetermined period has elapsed, the light emission period is ended. Specifically, the power supply line drive circuit 25 lowers the voltage of the power line PSL from V _ccH the V _ccL (T _1). Then, the source voltage V _s becomes V _ccL and the organic EL element 11 is quenched. Thereafter, driving corresponding to each of the above-described periods is executed. In this manner, the drive circuit 20 repeats the light emission period and the extinction period (V _th correction preparation period to writing period) for each frame period, and scans in the row direction for each horizontal line, for example.

  In the display device 1 of the present embodiment, as described above, the pixel circuit 14 is controlled to be turned on / off in each pixel 12, and a driving current is injected into the organic EL element 11 of each pixel 12. And recombine to emit light. This light is multiple-reflected between the anode and the cathode, passes through the cathode, etc., and is extracted outside. As a result, an image is displayed on the display panel 10.

(1.3 Action and effect)
By the way, in this embodiment, when the bootstrap operation is started after the gradation complementary writing is performed, the bootstrap operation is immediately stopped and the mobility correction is started. For example, when the voltage of the signal line DTL is V _sig1 and the voltage of the power supply line PSL is V _ccH , if the voltage of the scanning line WSL is lowered from V _on to V _off , the signal immediately The voltage of the line DTL is switched from V _sig1 to V _ofs2, and the voltage of the scanning line WSL is increased from V _off to V _on .

Furthermore, in the present embodiment, after the mobility correction is completed, when the bootstrap operation starts, the bootstrap operation is immediately stopped and the signal voltage is written. For example, when the voltage of the signal line DTL is V _ofs2 and the voltage of the power supply line PSL is V _ccH , if the voltage of the scanning line WSL is lowered from V _on to V _off , the signal immediately The voltage of the line DTL is switched from V _ofs2 to V _sig2, and the voltage of the scanning line WSL is lowered from V _on to V _off .

As described above, in this embodiment, the mobility correction is performed before the second signal writing. Thereby, for example, even after bootstrap operation is started after gradation complementary writing is performed, the bootstrap operation is not stopped and mobility correction and writing are performed simultaneously (see FIG. 4). The mobility correction can be performed reliably. Therefore, for example, _{even when} the value of the second signal voltage V _sig2 is small, the mobility correction can be reliably performed regardless of the value of the second signal voltage V _sig2 , so that the low gradation Image quality can be improved.

<2. Modules and application examples>
Hereinafter, application examples of the display device described in the above embodiment will be described. The display device of the above embodiment is a television device, a digital camera, a notebook personal computer, a mobile terminal device such as a mobile phone, or a video camera, and the like. Alternatively, the present invention can be applied to display devices for electronic devices in various fields that display images.

(module)
The display device 1 according to the above embodiment is incorporated into various electronic devices such as application examples 1 to 5 described later, for example, as a module shown in FIG. In this module, for example, a region 210 exposed from the sealing substrate 32 is provided on one side of the substrate 31, and the wiring of the drive circuit 20 is extended to the exposed region 210 to provide an external connection terminal (not shown). Formed. The external connection terminal may be provided with a flexible printed circuit (FPC) 220 for signal input / output.

(Application example 1)
FIG. 6 illustrates an appearance of a television device to which the display device 1 of the above embodiment is applied. The television apparatus has, for example, a video display screen unit 300 including a front panel 310 and a filter glass 320. The video display screen unit 300 is configured by the display device 1 according to each of the above embodiments. Yes.

(Application example 2)
FIG. 7 shows the appearance of a digital camera to which the display device 1 of the above embodiment is applied. The digital camera includes, for example, a flash light emitting unit 410, a display unit 420, a menu switch 430, and a shutter button 440. The display unit 420 is configured by the display device 1 according to the above embodiment. Yes.

(Application example 3)
FIG. 8 shows the appearance of a notebook personal computer to which the display device 1 of the above embodiment is applied. The notebook personal computer has, for example, a main body 510, a keyboard 520 for inputting characters and the like, and a display unit 530 for displaying an image. The display unit 530 is a display according to each of the above embodiments. The apparatus 1 is configured.

(Application example 4)
FIG. 9 shows the appearance of a video camera to which the display device 1 of the above embodiment is applied. This video camera has, for example, a main body 610, a subject photographing lens 620 provided on the front side surface of the main body 610, a start / stop switch 630 at the time of photographing, and a display 640. Reference numeral 640 denotes the display device 1 according to each of the above embodiments.

(Application example 5)
FIG. 10 shows the appearance of a mobile phone to which the display device 1 of the above embodiment is applied. For example, the mobile phone is obtained by connecting an upper housing 710 and a lower housing 720 with a connecting portion (hinge portion) 730, and includes a display 740, a sub-display 750, a picture light 760, and a camera 770. Yes. The display 740 or the sub-display 750 is configured by the display device 1 according to each of the above embodiments.

  The present invention has been described above with the embodiments and application examples. However, the present invention is not limited to the above-described embodiments and the like, and various modifications can be made.

  For example, in the above-described embodiment, the case where the display device 1 is an active matrix type has been described. However, the configuration of the pixel circuit 14 for driving the active matrix is not limited to that described in the above-described embodiment, and is necessary. Depending on the case, a capacitor or a transistor may be added to the pixel circuit 14. In that case, a necessary drive circuit may be added in addition to the signal line drive circuit 23, the scanning line drive circuit 24, and the power supply line drive circuit 25 described above in accordance with the change of the pixel circuit 14.

  In the above embodiment and the like, the timing generation circuit 22 controls the driving of the signal line driving circuit 23, the scanning line driving circuit 24, and the power supply line driving circuit 25, but other circuits control these driving. You may do it. The control of the signal line drive circuit 23, the scanning line drive circuit 24, and the power supply line drive circuit 25 may be performed by hardware (circuit) or software (program).

  In the above-described embodiment and the like, the pixel circuit 14 has a 2Tr1C circuit configuration. However, if the transistor includes a circuit configuration in which the transistor is connected in series to the organic EL element 11, the 2Tr1C circuit configuration is used. A circuit configuration other than the configuration may be employed.

Further, in the above-described embodiment and the like, the case where the drive transistor Tr ₁ and the write transistor Tr ₂ are formed by n-channel MOS thin film transistors (TFTs) is illustrated, but a p-channel transistor is exemplified. (For example, a p-channel MOS type TFT) may be used. However, in this case, the source and drain of the transistor Tr ₂ that are not connected to the power supply line PSL and the other end of the storage capacitor C _s are connected to the cathode of the organic EL element 11 and the anode of the organic EL element 11 is connected. Is preferably connected to GND or the like.

DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 10 ... Display panel, 11, 11R, 11G, 11B ... Organic EL element, 12 ... Pixel, 13 ... Pixel circuit array part, 14 ... Pixel circuit, 20 ... Drive circuit, 20A ... Video signal, 20B ... synchronizing signal, 21 ... video signal processing circuit, 22 ... timing generator, 22A ... control signal, 23 ... signal line drive circuit, 24 ... scanning-line drive circuit, 25 ... power supply line drive circuit, C _s ... holding capacity, DTL ... Signal line, I _d ... current, PSL ... power supply line, Tr ₁ ... drive transistor, Tr ₂ ... write transistor, V _g ... gate voltage, V _gs ... gate-source voltage, V _s ... source voltage, V _th ... threshold Voltage, WSL ... scanning line.

Claims (3)

A plurality of scanning lines arranged in a row, a plurality of signal lines arranged in a column, a plurality of light emitting elements arranged in a matrix corresponding to the intersection of each scanning line and each signal line, and a plurality of light emitting elements A pixel circuit array unit including a pixel circuit of
A scanning line driving circuit that sequentially applies a selection pulse to the plurality of scanning lines to sequentially select the plurality of light emitting elements and the plurality of pixel circuits;
A signal that applies a gradation complementary voltage corresponding to a video signal, a fixed mobility correction voltage, and a signal voltage corresponding to the video signal to each signal line in this order to write to the pixel circuit to be selected. Line drive circuit and
The scanning line driving circuit applies a selection pulse to one scanning line within a period in which the signal line driving circuit applies the mobility correction voltage to the plurality of signal lines. A plurality of scanning lines arranged in a row, a plurality of signal lines arranged in a column, a plurality of light emitting elements arranged in a matrix corresponding to the intersection of each scanning line and each signal line, and a plurality of light emitting elements A pixel circuit array unit including a pixel circuit of
A scanning line driving circuit that sequentially applies a selection pulse to the plurality of scanning lines to sequentially select the plurality of light emitting elements and the plurality of pixel circuits;
A signal that applies a gradation complementary voltage corresponding to a video signal, a fixed mobility correction voltage, and a signal voltage corresponding to the video signal to each signal line in this order to write to the pixel circuit to be selected. Preparing a display device comprising: a line driving circuit;
Applying a selection pulse to one scanning line during a period in which the signal line driving circuit applies the mobility correction voltage to the plurality of signal lines using the scanning line driving circuit. Device driving method. A display device,
The display device
A plurality of scanning lines arranged in a row, a plurality of signal lines arranged in a column, a plurality of light emitting elements arranged in a matrix corresponding to the intersection of each scanning line and each signal line, and a plurality of light emitting elements A pixel circuit array unit including a pixel circuit of
A scanning line driving circuit that sequentially applies a selection pulse to the plurality of scanning lines to sequentially select the plurality of light emitting elements and the plurality of pixel circuits;
A signal that applies a gradation complementary voltage corresponding to a video signal, a fixed mobility correction voltage, and a signal voltage corresponding to the video signal to each signal line in this order to write to the pixel circuit to be selected. Line drive circuit and
The electronic device, wherein the scanning line driving circuit applies a selection pulse to one scanning line during a period in which the signal line driving circuit applies the mobility correction voltage to the plurality of signal lines.

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