JP2013047717A - Driving circuit, driving method, electronic apparatus and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress variation in luminance of each pixel constituting a display.SOLUTION: A first drive transistor supplies a first current from a drain to a source; and a second drive transistor supplies a second current from a drain to a source, in response to an increase in a source potential of the first drive transistor at a speed corresponding to the first current, in a correction period when a gate potential of the first drive transistor is set to be a signal potential of a video signal, and a voltage between the gate and the source of the first drive transistor is corrected; and a light emitting device emits light with brightness corresponding to the corrected voltage in the correction period, by the first current supplied from the source of the first drive transistor and the second current supplied from the source of the second drive transistor. This disclosure can be applied to e.g., a driving circuit as each pixel constituting an organic EL panel.

Description

  The present disclosure relates to a drive circuit, a drive method, an electronic device, and a display device, and in particular, for example, a drive circuit, a drive method, an electronic device, and a display device that can suppress variations in luminance of pixels included in a display. About.

  2. Description of the Related Art In recent years, development of flat self-luminous panels (hereinafter referred to as organic EL panels) using organic EL (Electro Luminescent) elements as light emitting elements has become active (see, for example, Patent Documents 1 to 5).

  This organic EL element is a light emitting element utilizing a phenomenon that emits light when an electric field is applied to an organic thin film, and is driven at an applied voltage of 10 V or less, and thus has low power consumption.

  In addition, since the organic EL element is a self-luminous element that emits light by itself, an illumination member such as a backlight is not required unlike a liquid crystal display, and thus it is easy to reduce the weight and thickness.

  Furthermore, since the organic EL element has a very high response speed of about several μs, an afterimage does not occur when displaying a moving image.

JP 2003-255856 A JP 2003-271095 A JP 2004-133240 A JP 2004-029791 A Japanese Patent Laid-Open No. 2004-093682

  However, in the above-described organic EL panel, the luminance of each pixel may vary.

  This indication is made in view of such a situation, and makes it possible to control the variation in the brightness of each pixel which constitutes a display.

  The driving circuit according to the first aspect of the present disclosure includes a first driving transistor that supplies a first current from a drain to a source, a gate potential of the first driving transistor being a signal potential of a video signal, The source potential of the first driving transistor rises at a rate corresponding to the first current during the correction period in which the voltage between the gate and source of the first driving transistor is corrected. Correspondingly, a second driving transistor for supplying a second current from the drain to the source, the first current supplied from the source of the first driving transistor, and the second driving transistor. And a light emitting element that emits light with brightness according to the voltage corrected in the correction period by the second current supplied from the source of the driving circuit.

  The gate of the first driving transistor and the gate of the second driving transistor are connected, and the source of the first driving transistor and the source of the second driving transistor are connected. Can be.

  A switching element that is turned from an off state to an on state in response to the source potential of the first driving transistor rising at a speed corresponding to the first current during the correction period; In the second drive transistor, the second current is supplied from the drain connected to the power supply line through the switching element to the source in response to the switching element being turned on. can do.

  The first driving transistor and the second driving transistor may be arranged such that directions of a gate, a drain, and a source coincide with each other.

  A driving method according to a first aspect of the present disclosure is a driving method of a driving circuit including a first driving transistor, a second driving transistor, and a light emitting element, and is based on the first driving transistor. A first supply step of supplying a first current from the drain to the source; and a gate potential of the first driving transistor by the second driving transistor is set as a signal potential of a video signal, Corresponding to the source potential of the first driving transistor rising at a rate corresponding to the first current during the correction period in which the voltage between the gate and source of the driving transistor is corrected. , A second supply step of supplying a second current from the drain to the source, the first current supplied from the source of the first driving transistor by the light emitting element, and the second driving G By the second current supplied from the source of Njisuta a driving method and a light emitting step of emitting light at brightness in accordance with the corrected the voltage at the correction period.

  The electronic device according to the first aspect of the present disclosure includes a first driving transistor that supplies a first current from a drain to a source, and a gate potential of the first driving transistor as a signal potential of a video signal. The source potential of the first driving transistor rises at a rate corresponding to the first current during the correction period in which the voltage between the gate and source of the first driving transistor is corrected. Correspondingly, a second driving transistor for supplying a second current from the drain to the source, the first current supplied from the source of the first driving transistor, and the second driving transistor. And a light emitting element that emits light with brightness according to the voltage corrected in the correction period by the second current supplied from the source.

  A display device according to a first aspect of the present disclosure includes a display panel that displays an image by causing a plurality of pixel units to emit light, and the pixel unit supplies a first current from a drain to a source. The first driving is performed during a correction period in which the gate potential of the transistor and the first driving transistor is set as the signal potential of the video signal, and the voltage between the gate and the source of the first driving transistor is corrected. A second driving transistor for supplying a second current from the drain to the source in response to the source potential of the transistor for use rising at a speed corresponding to the first current; and the first driving Brightness according to the voltage corrected in the correction period by the first current supplied from the source of the driving transistor and the second current supplied from the source of the second driving transistor. Depart A display device having a light emitting element for.

  According to the first aspect of the present disclosure, a first current is supplied from the drain to the source by the first driving transistor, and the gate of the first driving transistor is supplied by the second driving transistor. During the correction period in which the potential is the signal potential of the video signal and the voltage between the gate and the source of the first driving transistor is corrected, the source potential of the first driving transistor is the first current. And a second current is supplied from the drain to the source, and the light emitting element is supplied with the first current supplied from the source of the first driving transistor. The second current supplied from the source of the second driving transistor emits light with brightness according to the voltage corrected in the correction period.

  A drive circuit according to a second aspect of the present disclosure includes a first drive transistor, a second drive transistor, a switching transistor, a sampling transistor, a storage capacitor, and a light emitting element. One end is supplied with a video signal from a signal line via the sampling transistor, and the video signal is supplied to one end of the storage capacitor from a first power source via the first driving transistor. A correction period for supplying a current to the other end of the storage capacitor to correct a voltage between both ends of the storage capacitor, and from the first power source through the first driving transistor according to the corrected voltage. And a first current supplied from a second power source via the switching transistor and the second driving transistor in accordance with the corrected first voltage and the corrected voltage. By a current which is a driving circuit and a light emission period for light emitting the light emitting element.

  The switching transistor may be turned off during the correction period.

  The first power source and the second power source may be the same power source.

  An electronic apparatus according to a second aspect of the present disclosure includes a first driving transistor, a second driving transistor, a switching transistor, a sampling transistor, a storage capacitor, and a light emitting element, One end is supplied with a video signal from a signal line via the sampling transistor, and the video signal is supplied to one end of the storage capacitor from a first power source via the first driving transistor. A correction period for supplying a current to the other end of the storage capacitor to correct a voltage between both ends of the storage capacitor, and from the first power source through the first driving transistor according to the corrected voltage. And a first current supplied from a second power source via the switching transistor and the second driving transistor in accordance with the corrected first voltage and the corrected voltage. By the current is an electronic device having a light emission period for light emitting the light emitting element.

  According to the second aspect of the present disclosure, a video signal is supplied to one end of the storage capacitor from a signal line via the sampling transistor, and the video signal is supplied to one end of the storage capacitor during the correction period. In this state, a current is supplied from the first power supply to the other end of the storage capacitor via the first driving transistor, and the voltage across the storage capacitor is corrected. In the light emission period, A first current supplied from the first power supply via the first driving transistor according to the corrected voltage, and a switching transistor and the first current from a second power supply according to the corrected voltage. The light emitting element emits light by the second current supplied through the two driving transistors.

  According to the present disclosure, it is possible to suppress variation in luminance of each pixel constituting the display.

It is a block diagram which shows the structural example of the organic electroluminescent panel to which the basic drive method was applied. It is a block diagram which shows the detailed structural example of each pixel part which comprises the organic electroluminescent panel of FIG. It is a timing chart for explaining an example of operation of each pixel part. It is a figure which shows an example of the pixel part in light emission period T0. It is a figure which shows an example of the pixel part in the light extinction period T1. It is a figure which shows an example of the pixel part in threshold value correction preparation period T2. It is a figure which shows an example of the pixel part in threshold value correction period T3. It is a figure which shows an example of the pixel part in the writing + mobility correction period T4. It is a figure which shows an example of the pixel part in light emission period T5. It is a figure which shows an example in case the waveform of a scanning line electric potential changes according to the position of a pixel part. It is a figure which shows an example in case the nonuniformity arises in the brightness | luminance of each pixel part. It is a figure for demonstrating the outline | summary of this indication. It is a block diagram which shows the structural example of the organic electroluminescent panel in this indication. 6 is a timing chart for explaining an example of an operation of each pixel unit in the present disclosure. It is a figure which shows an example of the television receiver in this indication.

Hereinafter, embodiments of the present disclosure (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. 1. Background Description This embodiment (an example in which the driving transistor is divided and configured)
3. Modified example

<1. Background explanation>
First, in order to facilitate understanding of the present disclosure and to clarify the background, an organic EL panel to which a basic driving method (hereinafter referred to as a basic driving method) is applied will be described with reference to FIGS. I will explain.

  FIG. 1 shows a configuration example of an organic EL panel 11 to which the basic driving method is applied.

  The organic EL panel 11 is an active matrix organic EL panel, and includes a pixel array unit 21 and a data driver 41 and a gate driver 42 as a driving unit that drives the pixel array unit 21.

  In the pixel array unit 21, N × M pixel units 31- (1, 1) to 31- (N, M) are arranged in a matrix. N and M are integer values of 1 or more independent of each other.

  The data driver 41 and the gate driver 42 are configured by, for example, a driver IC (Integrated Circuit). In this example, the gate driver 42 is arranged on one side outside the pixel array unit 21. However, the arrangement of the gate driver 42 is not particularly limited. For example, the gate driver 42 may be arranged on both sides outside the pixel array unit 21.

  The gate driver 42 includes DS drivers 51-1 to 51-N and WS drivers 52-1 to 52-N.

  The organic EL panel 11 also has N scanning lines WSL-1 to WSL-N, N power supply lines DSL-1 to DSL-N, and M video signal lines DTL-1 to DTL-M. doing.

  In the case where there is no need to particularly distinguish each of the scanning lines WSL-1 to WSL-N, the video signal lines DTL-1 to DTL-M, and the power supply lines DSL-1 to DSL-N, hereinafter, the scanning lines WSL are simply referred to. These are referred to as a video signal line DTL and a power supply line DSL, respectively.

  In addition, it is not necessary to particularly distinguish each of the pixel units 31- (1, 1) to 31- (N, M), the DS drivers 51-1 to 51-N, and the WS drivers 52-1 to 52-N. In this case, they are simply referred to as the pixel unit 31, the DS driver 51, and the WS driver 52, respectively.

  As shown in FIG. 1, the pixel units 31- (1,1) to 31- (1, M) in the first row are composed of the WS driver 52-1 on the scanning line WSL-1 and the power line DSL-1. Each is connected to the DS driver 51-1. The pixel units 31- (N, 1) to 31- (N, M) in the Nth row include a WS driver 52-N on the scanning line WSL-N and a DS driver 51-N on the power line DSL-N, respectively. It is connected. Although not shown, the same connection is made for the pixel portions 31 in the other rows.

  Further, the pixel portions 31- (1,1) to 31- (N, 1) in the first column are connected to the data driver 41 through the video signal line DTL-1. The pixel units 31- (1,2) to 31- (N, 2) in the second column are connected to the data driver 41 through the video signal line DTL-2. The pixel units 31- (1, M) to 31- (N, M) in the M-th column are connected to the data driver 41 through video signal lines DTL-M. Although not shown, the same connection is made for the pixel units 31 in other columns.

  The gate driver 42 sequentially drives the WS drivers 52-1 to 52 -N, thereby sequentially switching the potentials of the scanning lines WSL- 1 to WSL-N in a horizontal period (hereinafter referred to as 1H) to thereby change the pixel unit 31. Line-sequential scanning is performed line by line. Further, the gate driver 42 drives the DS drivers 51-1 to 51-N to switch the potentials of the power supply lines DSL-1 to DSL-N to a high potential or a low potential in accordance with the line sequential scanning. The data driver 41 switches the potentials of the video signal lines DTL-1 to DTL-M between the video signal signal voltage Vsig and the reference voltage Vofs within each 1H in accordance with the line sequential scanning.

[Detailed Configuration Example of Pixel Unit 31]
Next, FIG. 2 shows a detailed configuration example of each pixel unit 31 constituting the organic EL panel 11.

  In FIG. 2, one of the N × M pixel units 31 included in the organic EL panel 11 is enlarged and drawn.

  The pixel unit 31 includes a sampling transistor 91, a driving transistor 92, a storage capacitor 93, a light emitting element 94 that is an organic EL element, and an auxiliary capacitor 95. An equivalent circuit of the EL element ELP97 can be represented by a light emitting element 94 and an auxiliary capacitor 95.

  The pixel unit 31 includes two transistors, a sampling transistor 91 and a driving transistor 92. The drive circuit having such a configuration is referred to as a 2Tr (transistor) drive circuit. The pixel unit 31 is not limited to the 2Tr drive circuit.

  Each of the sampling transistor 91 and the driving transistor 92 is composed of an N-channel transistor. The gate of the sampling transistor 91 is connected to the scanning line WSL. The drain of the sampling transistor 91 is connected to the video signal line DTL. The source of the sampling transistor 91 is connected to the gate G of the driving transistor 92.

  The drain of the driving transistor 92 is connected to the power supply line DSL. The source S of the driving transistor 92 is connected to the anode of the light emitting element 94. The gate G of the driving transistor 92 is connected to the source of the sampling transistor 91.

  The storage capacitor 93 is connected between the gate G and the source S of the driving transistor 92. Hereinafter, the capacitance value of the storage capacitor 93 is described as Cs. The cathode of the light emitting element 94 is connected to the wiring 96. Therefore, the value of the cathode potential of the light emitting element 94 becomes the potential Vcath of the wiring 96.

  The auxiliary capacitor 95 is connected between the anode of the light emitting element 94 (source S of the driving transistor 92) and the wiring 96. The capacitance value of the auxiliary capacitor 95 is hereinafter referred to as Csub.

  Since the light-emitting element 94 is a current light-emitting element, the gradation of light emission luminance can be varied by controlling the current value. In the pixel portion 31, the current value of the light emitting element 94 is controlled by changing the potential of the gate G of the driving transistor 92 (hereinafter referred to as the gate potential), and as a result, the gradation of the light emission luminance is varied.

  The driving transistor 92 is designed to operate in a saturation region. That is, the drain of the driving transistor 92 is connected to the power supply line DSL, and the driving transistor 92 operates in the saturation region by setting the potential of the power supply line DSL to a high potential.

  Note that the saturation region is a region where Vgs−Vth <Vds is satisfied. Vds indicates a voltage between the drain and source S of the driving transistor 92 (hereinafter referred to as a drain-source voltage). Vth represents the threshold voltage of the driving transistor 92. Vgs represents a voltage between the gate G and the source S of the driving transistor 92 (hereinafter referred to as a gate-source voltage).

The driving transistor 92 operating in the saturation region functions as a constant current source for flowing a constant current between the drain and the source S. The current flowing between the drain and the source S of the driving transistor 92 is hereinafter referred to as a drain-source current, and the current value is described as Ids. This drain-source current Ids can be expressed by the following equation (1).
Ids = (1/2) × μ × (W / L) × Cox × (Vgs-Vth) ² (1)

  In equation (1), μ represents mobility, W represents gate width, L represents gate length, and Cox represents gate oxide film capacitance per unit area.

  The sampling transistor 91 is turned on (conductive) in accordance with the potential of the control signal supplied from the WS driver 52 via the scanning line WSL. When the sampling transistor 91 is turned on, the holding capacitor 93 holds the signal potential Vsig of the video signal supplied from the data driver 41 via the video signal line DTL.

  The driving transistor 92 is supplied with a current from the power supply line DSL at a high potential, and causes a drain-source current corresponding to the signal potential Vsig held in the holding capacitor 93 to flow through the light emitting element 94. Hereinafter, the drain-source current flowing through the light emitting element 94 is also referred to as a driving current as appropriate. When a drive current of a certain level or more flows through the light emitting element 94, the light emitting element 94 (pixel unit 31) emits light.

  The pixel unit 31 has a threshold correction function. The threshold correction function is a function for holding the voltage corresponding to the threshold voltage Vth of the driving transistor 92 in the holding capacitor 93. By this threshold value correction function, the influence of the variation in the threshold voltage Vth of the driving transistor 92 can be canceled. The variation in the threshold voltage Vth of the driving transistor 92 is one of the causes of variation in the light emission luminance for each pixel unit 31. Therefore, the threshold correction function can suppress variations in the light emission luminance of each pixel unit 31 to some extent.

  The pixel unit 31 further has a mobility correction function in addition to the threshold correction function described above. The mobility correction function is a function of correcting the mobility μ of the driving transistor 92 with respect to the signal potential Vsig when the signal potential Vsig is held in the holding capacitor 93.

  The pixel unit 31 further has a bootstrap function. The bootstrap function is a function that links the potential of the gate G with the fluctuation of the potential of the source S of the driving transistor 92. In other words, the bootstrap function is a function for maintaining the gate-source voltage of the driving transistor 92 constant.

[Description of Operation of Pixel Unit 31]
Next, an operation example of the pixel unit 31 will be described with reference to the timing chart of FIG.

  4 to 9 show the state of the driving transistor 92 in a light emission period T0, a quenching period T1, a threshold correction preparation period T2, a threshold correction period T3, a writing + mobility correction period T4, and a light emission period T5, which will be described later. An example is shown.

  FIG. 3 shows the potential of the video signal line DTL (hereinafter also referred to as video signal line potential DT), the potential of the power supply line DSL (hereinafter also referred to as power supply line potential DS), and the scanning line with respect to the time axis in the horizontal direction in the figure. An example of changes in the potential of WSL (hereinafter also referred to as a scanning line potential WS), the gate potential Vg of the driving transistor 92, and the source potential Vs of the driving transistor 92 is shown.

In FIG. 3, the period up to time t1 is a light emission period T0 in which the light emitting element 94 emits light. In the light emission period T0, as shown in FIG. 4, the power supply line potential DS of the power supply line DSL is set to the high potential V _{CC — H,} and the sampling transistor 91 is turned off.

  Further, since the driving transistor 92 is set to operate in the saturation region in the light emission period T0, the current Ids ′ flowing through the EL element ELP97 is a value calculated by the equation (1).

In FIG. 3, a period from time t1 to time t3 is an extinction period T1 in which the light emitting element 94 is extinguished. At time t1, the data driver 41 switches the video signal line potential DT from the reference potential Vofs to the signal potential Vsig. At time t1, the DS driver 51 switches the power supply line potential DS from the high potential V _{CC_H} to the low potential V _{CC_L} so that the pixel unit 31 is in the state shown in FIG.

As a result, the gate potential Vg decreases during the period from time t1 to time t2, and the source potential Vs also decreases due to coupling via the storage capacitor 93. As shown in FIG. 3, the source potential Vs drops to the low potential V _{CC_L} .

At this time, the source potential Vs (= V _CC — _L ) ≦ Vthel + Vcath is satisfied, the driving transistor 92 is cut off, and the light emitting element 94 stops emitting light. That is, the light emitting element 94 is quenched. Note that Vthel represents an EL threshold voltage of the light emitting element 94.

Further, in the extinguishing period T1, the scanning line potential WS is set to the low potential V _{WS_L} .

  A period from time t3 to time t4 is a threshold correction preparation period T2 in which preparation for threshold correction is performed. In order to perform threshold correction, the gate-source voltage Vgs of the driving transistor 92 needs to be larger than the threshold voltage Vth.

  Therefore, in the threshold correction preparation period T2, preparation for threshold correction is performed so that the gate-source voltage Vgs of the driving transistor 92 is larger than the threshold voltage Vth (Vgs> Vth).

  The threshold correction preparation period T2 may be divided into a plurality of divided periods (for example, a period from time t3 to time t4 and a period from time t5 to time t6), as shown in FIG. One continuous period (for example, only a period from time t3 to time t4) may be used.

  In other words, when Vgs> Vth is established by preparation for threshold correction performed between time t3 and time t4, it is not necessary to prepare for threshold correction during the period from time t5 to time t6. In addition, when Vgs> Vth is not satisfied due to threshold correction preparation performed between time t3 and time t4, preparation for threshold correction needs to be performed in a period from time t5 to time t6.

Immediately before time t3, the data driver 41 switches the video signal line potential DT from the signal potential to Vsig from the reference potential Vofs. At time t3, the WS driver 52 _changes the scanning line potential WS from the low potential V _{WS_L} to the high potential. _Switch to potential V _{WS_H} .

As a result, as shown in FIG. 6, the sampling transistor 91 is turned on at time t3 when the scanning line potential WS is switched to the high potential V _{WS_H} , and the gate potential Vg becomes higher than the reference potential Vofs. Is done.

As a result, the gate-source voltage Vgs is set to the voltage (Vofs−V _CC — _L ), rises by the reference potential Vofs from the voltage during the extinguishing period T1, and Vgs> Vth.

A period from time t7 to time t8 is a threshold correction period T3 in which the first threshold correction is performed. Time t7 is time indicating the timing after the video signal line potential DT is switched to the reference potential Vofs and the scanning line potential WS is switched to the high potential V _{WS_H} .

At time t7, the DS driver 51 switches the power supply line potential DS from the low potential V _{CC_L} to the high potential V _{CC_H} .

At time t7, since the scanning line potential WS is set to the high potential V _{WS_H} , the sampling transistor 91 is turned on. In addition, since the power supply line potential DS is switched to the high potential V _{CC_H} , the anode of the light emitting element 94 becomes the source of the driving transistor 92.

  Then, as shown in FIG. 7, a current flows from the drain of the driving transistor 92 to the source S, and the source potential Vs rises.

  For this reason, as long as Vs ≦ Vthel + Vcath, that is, if the leakage current of the EL element ELP97 is sufficiently smaller than the current flowing through the driving transistor 92, the current flowing through the driving transistor 92 will be Used to charge the capacitor 95.

  Thus, the source potential Vs rises as time passes from time t7 to time t8 as shown in FIG.

  From time t7 to time t8, the gate potential Vg is constant. As a result, the gate-source voltage Vgs decreases, and the threshold voltage Vth is written to the storage capacitor 93.

At time t8, the WS driver 52 switches the scanning line potential WS from the high potential V _{WS_H} to the low potential V _{WS_L} to turn off the sampling transistor 91. As a result, the state of the gate G of the driving transistor 92 becomes a floating state.

  In the example shown in FIG. 3, the threshold correction from time t7 to time t8 is insufficient. That is, Vgs> Vth at time t8. In this case, during the period from time t8 to time t9, current flows from the drain to the source S, and the gate voltage Vg and the source voltage Vs rise simultaneously. During this period, the gate-source voltage Vgs is maintained.

  As long as Vs ≦ Vthel + Vcat, the EL element ELP97 is reverse-biased and therefore does not emit light.

  In this example, threshold correction is performed four times within one frame period (hereinafter referred to as 1F) in which one frame is displayed. However, the number of threshold corrections within 1F is not limited to four.

  A period from time t9 to time t10 is a threshold correction period T3 in which the second threshold correction is performed. Time t9 is time indicating the timing after the video signal line potential DT is switched to the reference potential Vofs.

At time t9, the WS driver 52 switches the scanning line potential WS from the low potential V _{WS_L} to the high potential V _{WS_H} and turns on the sampling transistor 91. At time t9, the video signal line potential DT is the reference potential Vofs.

  As a result, the gate potential Vg of the driving transistor 92 is set to the reference potential Vofs. Further, a current flows from the drain of the driving transistor 92 to the source S, and the source potential Vs rises. As a result, the gate-source voltage Vgs decreases, and writing to the storage capacitor 93 is performed.

Time t10 is a timing before the video signal line potential is switched to the signal potential Vsig. At time t10, the WS driver 52 switches the scanning line potential WS from the high potential V _{WS_H} to the low potential V _{WS_L} to turn off the sampling transistor 91.

  As a result, the state of the gate G of the driving transistor 92 becomes a floating state. In this example, the second threshold correction is insufficient. That is, Vgs> Vth at time t10. In this case, during the period from time t10 to time t11, current flows from the drain to the source S, and the gate potential Vg and the source potential Vs rise. During this period, the gate-source voltage Vgs is maintained.

  A period from time t11 to time t12 is a threshold correction period T3 in which the third threshold correction is performed, and the same threshold correction is performed as in the threshold correction period T3 in which the second threshold correction is performed.

  In this example, the third threshold correction is insufficient. That is, Vgs> Vth at time t12. In this case, during the period from time t12 to time t13, current flows from the drain to the source S, and the gate potential Vg and the source potential Vs rise. During this period, the gate-source voltage Vgs is maintained.

A period from time t13 to time t14 is a threshold correction period T3 in which the fourth threshold correction is performed. Time t13 is time indicating the timing after the video signal line potential is switched to the reference potential Vofs. At time t13, the WS driver 52 switches the scanning line potential WS from the low potential V _{WS_L} to the high potential V _{WS_H} and turns on the sampling transistor 91.

  As a result, the gate potential Vg of the driving transistor 92 becomes the reference potential Vofs. Further, a current flows from the drain of the driving transistor 92 to the source S, and the source potential Vs rises. As a result, the gate-source voltage Vgs decreases, and writing to the storage capacitor 93 is performed. This writing is performed until the driving transistor 92 is cut off, that is, until Vgs = Vth is satisfied. In the example of FIG. 3, Vgs = Vth is satisfied between time t14 and time t15.

  A period from time t15 to time t16 is a writing + mobility correction period T4 in which video signal writing and mobility correction are performed. Time t15 is a time indicating the timing after the video signal line potential DT is switched to the signal potential Vsig.

At time t15, the WS driver 52 switches the scanning line potential WS from the low potential V _{WS_L} to the high potential V _{WS_H} and turns on the sampling transistor 91 as shown in FIG. As a result, the gate potential Vg rises from the reference potential Vofs to the signal potential Vsig as shown in FIG. The signal potential Vsig is supplied (applied) to one end of the storage capacitor 93 (one end connected to the gate side of the driving transistor 92) via the sampling transistor 91.

  The driving transistor 92 supplies current from the drain to the source, so that the other end of the storage capacitor 93 (the other end connected to the source side of the driving transistor 92) is connected to the drain of the driving transistor 92. Current is supplied through the source. As a result, the signal potential Vsig is written into the storage capacitor 93 in a form to be added to the threshold voltage Vth, and is written into the storage capacitor 93 in a form in which the mobility correction voltage ΔVμ is subtracted. That is, Vsig + Vth−ΔVμ is written in the storage capacitor 93. As a result, the source potential Vs of the driving transistor 92 rises to VsO, and the gate-source voltage Vgs is corrected to Vsig−Vs0 (= Vsig + Vth−ΔVμ). In other words, the voltage (potential difference) between both ends of the storage capacitor 93 is corrected to Vsig + Vth−ΔVμ.

  After time t16 is a light emission period T5 in which the light emitting element 94 emits light. Time t16 is time indicating the timing before the video signal line potential DT is switched to the reference potential Vofs.

At time t16, as shown in FIG. 9, the WS driver 52 switches the scanning line potential WS from the high potential V _{WS_H} to the low potential V _{WS_L} and turns off the sampling transistor 91. As a result, the state of the gate G of the driving transistor 92 becomes a floating state. Then, the bootstrap operation is performed, and the gate potential Vg and the source potential Vs of the driving transistor 92 rise while the voltage (Vsig + Vth−ΔVμ) written in the storage capacitor 93 is maintained.

  The operation of the pixel unit 31 in the light emission period T5 is as follows in more detail. That is, the driving transistor 92 supplies the light emitting element 94 with a constant driving current Ids corresponding to the voltage (Vsig + Vth−ΔVμ) written in the storage capacitor 93.

As a result, the source potential Vs, that is, the anode potential of the light emitting element 94 (hereinafter referred to as the anode potential) rises to the voltage V _EL (> Vthel + Vcath) through which the drive current Ids flows, and the light emitting element 94 The state 94 shifts to a light emitting state.

Here, since the voltage (Vsig + Vth−ΔVμ) written to the storage capacitor 93 is a voltage across the storage capacitor 93, the gate-source voltage Vgs = Vsig + Vth−ΔVμ. Therefore, the drive current Ids supplied to the light emitting element 94 is (1/2) × μ × (W / L) × Cox × ((1)) according to the gate-source voltage Vgs = Vsig + Vth−ΔVμ. Vsig−ΔVμ) ² .

  That is, in the writing + mobility correction period T4, the voltage across the storage capacitor 93 is corrected to the voltage (Vsig + Vth−ΔVμ), whereby characteristics of the driving transistor 92 (for example, the gate width W and the gate length L) are corrected. The current Ids based on the gate oxide film capacitance Cox) is changed to a constant drive current Ids according to the gate-source voltage (Vsig + Vth−ΔVμ).

Incidentally, in the writing + mobility correction period T4, as shown in FIG. 3, the waveform of the scanning line potential WS changes from the low potential V _{WS_L} to the high potential V _{WS_L} at time t15, and at time t16, the high potential It has been described as changing from V _{WS_L} to the low potential V _{WS_L} .

  However, in practice, the waveform of the scanning line potential WS varies depending on the position of the pixel unit 31.

  Next, FIG. 10 shows an example in which the waveform of the scanning line potential WS differs depending on the position of the pixel portion 31.

  FIG. 10A shows an example of the scanning line potential WS, gate potential Vg, and source potential Vs in the writing + mobility correction period T4 in the pixel unit 31 provided near the WS driver 52 (gate driver 42). Yes.

  FIG. 10B shows an example of the scanning line potential WS, the gate potential Vg, and the source potential Vs in the writing + mobility correction period T4 in the pixel portion 31 provided far from the WS driver 52.

  In the pixel unit 31 provided in the vicinity of the WS driver 52, the waveform of the scanning line potential WS is steep as shown in FIG. 10A. For this reason, in the write + mobility correction period T4, the waveform of the gate potential Vg becomes steep, and the source potential Vs greatly increases due to the mobility correction.

  On the other hand, in the pixel unit 31 provided far from the WS driver 52, the waveform of the scanning line potential WS is distorted as shown in FIG. 10B. For this reason, in the writing + mobility correction period T4, the waveform of the gate potential Vg is lost, and the source potential Vs rises more slowly than in the case of FIG. 10A.

  For this reason, in the pixel unit 31 provided near the WS driver 52, as shown in FIG. 10A, the gate-source voltage Vgs is small, so that the pixel unit 31 has low luminance (the light emitting element 94 has low luminance). ).

  Further, in the pixel unit 31 provided far from the WS driver 52, as shown in FIG. 10B, the gate-source voltage Vgs increases, and thus the pixel unit 31 has high luminance (the light emitting element 94 has high luminance). Light emission).

  Therefore, as shown in FIG. 11, in the organic EL panel 11, unevenness in luminance occurs in each pixel unit 31 constituting the pixel array unit 21.

<2. Embodiment>
[Outline of this disclosure]
Next, FIG. 12 shows an overview of the present disclosure.

  12A and 12B show examples of the scanning line potential WS, the gate potential Vg, and the source potential Vs in the writing + mobility correction period T4 in the pixel unit 31 provided near the WS driver 52 (gate driver 42). This is indicated by a solid line.

  That is, FIG. 12A shows an example in which the gate-source voltage Vgs becomes small and the pixel portion 31 has low luminance in the writing + mobility correction period T4.

  In FIG. 12B, in the writing + mobility correction period T4, the rise of the source potential Vs is moderate, so that the gate-source voltage Vgs becomes large and the pixel portion 31 has high luminance. An example is shown.

  12A and 12B, for comparison, the scanning line potential WS, the gate potential Vg, and the source potential Vs in the writing + mobility correction period T4 in the pixel portion 31 provided far from the WS driver 52 are shown. An example is indicated by a dotted line.

  Here, as the current flowing from the drain to the source S of the driving transistor 92 increases, the charging time t required for charging the storage capacitor 93 becomes shorter.

  This is clear from t = CV / i derived from CV = it. C represents the capacitance of the storage capacitor 93, V represents the voltage across the storage capacitor 93, and current i represents the current flowing through the storage capacitor 93.

  Further, as the charging time t is shorter, the source potential Vs increases more in the writing + mobility correction period T4 as shown in FIG. 12A. In this case, the gate-source voltage Vgs becomes small, and the pixel unit 31 has low luminance.

  On the other hand, as the charging time t is longer, the source potential Vs becomes smaller in the writing + mobility correction period T4 as shown in FIG. 12B. In this case, the gate-source voltage Vgs becomes large, and the pixel unit 31 has high luminance.

  Therefore, for example, in the pixel unit 31 provided near the WS driver 52, the current flowing from the drain to the source S of the driving transistor 92 is decreased, and the charging time t is lengthened.

  As a result, in the writing + mobility correction period T4, the degree of increase in the source potential Vs becomes as shown in FIG. 12B from that shown in FIG. 12A.

  For this reason, for example, a situation in which the pixel unit 31 provided near the WS driver 52 becomes low in luminance can be suppressed, and therefore, luminance unevenness occurs due to the luminance of each pixel unit 31 being different. Can be suppressed.

[Configuration example of organic EL panel 111]
FIG. 13 shows a configuration example of the organic EL panel 111 according to the present embodiment.

  Note that, in this organic EL panel 111, the same reference numerals are given to portions configured in the same manner as the organic EL panel 11 in FIG.

  That is, the organic EL panel 111 is provided with a gate driver 42 ′ having a new DS driver 131 in addition to the DS driver 51 and the WS driver 52 instead of the gate driver 42.

  The organic EL panel 111 is provided with a pixel unit 31 ′ having a new switching transistor 151 and a driving transistor 152 in addition to the sampling transistor 91 to the EL element ELP 97 instead of the pixel unit 31. . Other than that is the same as the organic EL panel 11 of FIG.

  In order to distinguish the power lines connected to the DS driver 51 and the DS driver 131, the power line connected to the DS driver 51 is hereinafter referred to as DSL1, and the power line connected to the DS driver 131 is referred to as DSL2. .

  The DS driver 131 is driven by the gate driver 42 'and switches the potential of the power supply line DSL2 to a high potential or a low potential.

  Each of the switching transistor 151 and the driving transistor 152 is an N-channel transistor. The gate of the switching transistor 151 is connected to the power supply line DSL2. The drain of the switching transistor 151 is connected to the power supply line DSL1. The source of the switching transistor 151 is connected to the drain of the driving transistor 152.

  In FIG. 13, the drain of the driving transistor 92 is connected to the power supply line DSL1. Therefore, current is supplied from the same power source to the drain of the driving transistor 92 and the drain of the switching transistor 151 via the power supply line DSL1.

  In FIG. 13, the drain of the switching transistor 151 is connected to the power supply line DSL1, but may be connected to another power supply line different from the power supply line DSL1. Then, a current may be supplied to the drain of the switching transistor 151 from another power source that is different from the first power source that supplies current to the drain of the driving transistor 92 via another power supply line. .

  However, in this case, since the first power supply and the second power supply need to supply the same current at the same timing, they must be electrically connected to function as a single power supply. Is desirable.

  The drain of the driving transistor 152 is connected to the source of the switching transistor 151.

  The driving transistor 152 has the same source S and gate G as the driving transistor 92. That is, the source S of the driving transistor 152 is connected to the anode of the light emitting element 94. The gate G of the driving transistor 92 is connected to the source of the sampling transistor 91.

  Similarly to the driving transistor 92, the driving transistor 152 is designed to operate in a saturation region. The driving transistor 152 operating in the saturation region functions as a constant current source that allows a constant current to flow between the drain and the source S.

  Note that in the light emission period T5, the first driving current is supplied from the driving transistor 152 to the light emitting element 94, and the second driving current is supplied from the driving transistor 92 to the light emitting element. In addition, the driving transistor 152 and the driving transistor 92 are configured so that the sum of the first driving current and the second driving current becomes the driving current Ids.

  As is clear from Equation (1), the drive current Ids is a value based on the characteristics of the drive transistor (for example, the gate width W, the gate length L, and the gate oxide film capacitance Cox). For example, the drive current Ids is proportional to the gate width W and inversely proportional to the gate length L. Therefore, for example, in the case of FIG. 13, the driving transistor 92 is configured such that the gate width is W / 2 and the gate length is L. In the driving transistor 152, the gate width is W / 2 and the gate length is L.

  Thus, the first driving current supplied from the driving transistor 152 to the light emitting element 94 and the second driving current supplied from the driving transistor 92 to the light emitting element 94 are configured as shown in FIG. In this case, the drive current Ids that flows through the light emitting element 94 is half of the current. In this case, the driving transistor 92 in FIG. 2 is configured to have a gate width of W and a gate length of L. In Expression (1), mobility μ, gate oxide film capacitance Cox, gate-source voltage Vgs, and threshold voltage Vth are the same in driving transistor 92 in FIG. 2 and driving transistors 92 and 152 in FIG. Suppose that

  Therefore, in the write + mobility correction period T4, the amount of current (drive current) flowing from the drain to the source S of the drive transistor 92 is half that of the configuration shown in FIG. The charging time t required for charging is doubled.

  Therefore, the degree of increase in the source potential Vs can be changed from that shown in FIG. 12A to that shown in FIG. 12B, for example.

[Description of Operation of Pixel Unit 31 ']
Next, an operation example of the pixel unit 31 ′ will be described with reference to the timing chart of FIG.

  In FIG. 14, the processing described in FIG. 3 is performed until the end time t16 of the writing + mobility correction period T4. For this reason, in FIG. 14, only the writing + mobility correction period T4 and the periods before and after the period are simply illustrated.

That is, the DS driver 131 sets the power supply line potential of the power supply line DSL2 to the low potential V _{CC_L} until the end time t16 of the writing + mobility correction period T4, and the switching transistor 151 remains off.

  As a result, when the switching transistor 151 is off, that is, until the end time t16 of the writing + mobility correction period T4, the pixel unit 31 ′ performs FIG. 2 (FIG. 3) in the same manner as the pixel unit 31. It will operate as described with reference to it.

  However, the driving transistor 92 of FIG. 13 is different from the case of FIG. 2 in that it supplies half of the current supplied by the driving transistor 92 of FIG.

  Thereby, in the writing + mobility correction period T4, the rising speed of the source potential Vs is ½ times that of the configuration shown in FIG. 2, and the luminance of the pixel unit 31 is lower than the conventional luminance. can do. Therefore, it is possible to suppress unevenness in luminance in the pixel unit 31.

After the end of the writing + mobility correction period T4, a transition is made to the light emission period T5. At this time, the DS driver 131 switches the power supply line potential of the power supply line _DSL2 from the low potential V _{CC_L} to the high potential V _{CC_H} and turns on the switching transistor 151 as shown in FIG.

Thereby, in the driving transistor 92 and the driving transistor 152, the potentials of the respective drains become the same high potential V _{CC — H.}

  In the driving transistor 92 and the driving transistor 152, the gates are connected to each other and the sources are connected to each other. Therefore, the gate potential Vg of the driving transistor 92 and the driving transistor 152 is the same.

  Similarly, the source potential Vs of the driving transistor 92 and the driving transistor 152 is also the same potential.

  Accordingly, in the light emission period T5, the driving transistor 92 supplies a constant drive current (Ids / 2) corresponding to the voltage (Vsig + Vth−ΔVμ) written in the storage capacitor 93 to the light emitting element 94.

  Here, the voltage (Vsig + Vth−ΔVμ) written in the storage capacitor 93 is a voltage across the storage capacitor 93. Therefore, the gate-source voltage Vgs = Vsig + Vth−ΔVμ.

In the driving transistor 92, the gate width is W / 2 and the gate length is L. Therefore, the driving current supplied from the driving transistor 92 to the light emitting element 94 is (Ids / 2) = (1/2) × μ × (W / 2 × 1 / L) × Cox × from the equation (1). (Vsig−ΔVμ) ²

  That is, in the writing + mobility correction period T4, the voltage across the storage capacitor 93 is corrected to the voltage (Vsig + Vth−ΔVμ), whereby the current (amount) based on the characteristics of the driving transistor 92 is changed to the voltage ( It is changed to a constant drive current (Ids / 2) according to Vsig + Vth−ΔVμ. Accordingly, the current based on the characteristics of the driving transistor 152 is similarly changed to a constant driving current (Ids / 2) corresponding to the voltage (Vsig + Vth−ΔVμ).

  In the light emission period T5, the driving transistor 152 emits a constant driving current (Ids / 2) corresponding to the voltage (Vsig + Vth−ΔVμ) written in the storage capacitor 93 in the same manner as the driving transistor 92. 94.

  As a result, the drive current Ids (= (Ids / 2) + (Ids / 2)) similar to that configured as shown in FIG. 2 is supplied to the light emitting element 94.

<3. Modification>
In this embodiment, a driving current (Ids / 2) is supplied from the driving transistor 92 to the light emitting element 94, and a driving current (Ids / 2) is supplied from the driving transistor 152 to the light emitting element 94. To supply.

  However, the driving current supplied from the driving transistor 92 to the light emitting element 94 is not limited to the driving current (Ids / 2), and can be changed by changing the gate width W or the gate length L of the driving transistor 92. Can do.

  Thereby, in the writing + mobility correction period T4, the current used to increase the source potential can be made different depending on the position of the pixel portion 31 ′.

  That is, for example, in the writing + mobility correction period T4, the pixel unit 31 ′ causes a smaller current to flow closer to the WS driver 52 to increase the luminance. Further, for example, as the pixel unit 31 ′ is farther from the WS driver 52, more current is passed so that the luminance is lowered.

  As a result, it is possible to suppress the occurrence of uneven brightness depending on the position of the pixel unit 31 ′.

  In the pixel unit 31 ′, the driving transistor 92 and the driving transistor 152 are arranged so that the directions of the gate, the drain, and the source coincide with each other, and the characteristics of the driving transistor 92 and the driving transistor 152 are the same. It is trying to become.

  Therefore, even when threshold correction or mobility correction is performed using only the driving transistor 92, the same effect as that obtained by correcting the threshold or mobility of the driving transistor 152 can be obtained.

In addition, this indication can also take the following structures.
(1) A first driving transistor that supplies a first current from a drain to a source, and a gate potential of the first driving transistor is set as a signal potential of a video signal, and the gate of the first driving transistor Corresponding to the rise of the source potential of the first driving transistor at a speed corresponding to the first current during the correction period in which the voltage between the source and the source is corrected. A second driving transistor that supplies a second current, the first current supplied from the source of the first driving transistor, and the second current supplied from the source of the second driving transistor. And a light emitting element that emits light with brightness corresponding to the voltage corrected in the correction period.
(2) The gate of the first driving transistor is connected to the gate of the second driving transistor, and the source of the first driving transistor and the source of the second driving transistor are The drive circuit according to (1), which is connected.
(3) A switching element that is turned from an off state to an on state in response to the source potential of the first driving transistor rising at a speed corresponding to the first current during the correction period. In addition, the second driving transistor supplies the second current from the drain connected to the power supply line via the switching element to the source in response to the switching element being turned on. The drive circuit according to (2).
(4) The drive circuit according to any one of (1) to (3), wherein the first drive transistor and the second drive transistor are arranged so that directions of a gate, a drain, and a source thereof coincide with each other. .
(5) In a driving method of a driving circuit including a first driving transistor, a second driving transistor, and a light emitting element, a first current is supplied from the drain to the source by the first driving transistor. The gate potential of the first drive transistor by the first supply step and the second drive transistor is set as the signal potential of the video signal, and between the gate and source of the first drive transistor. The second current is supplied from the drain to the source in response to the source potential of the first driving transistor rising at a speed corresponding to the first current during the correction period in which the voltage is corrected. A second supply step, the first current supplied from the source of the first driving transistor by the light emitting element, and the source supplied from the source of the second driving transistor. Wherein the second current, the driving method including the light emitting step of emitting light at brightness in accordance with the corrected the voltage at the correction period.
(6) A first driving transistor that supplies a first current from the drain to the source, and the gate potential of the first driving transistor is set as the signal potential of the video signal, and the gate of the first driving transistor Corresponding to the rise of the source potential of the first driving transistor at a speed corresponding to the first current during the correction period in which the voltage between the source and the source is corrected. A second driving transistor that supplies a second current, the first current supplied from the source of the first driving transistor, and the second current supplied from the source of the second driving transistor. And a light emitting element that emits light with brightness according to the voltage corrected in the correction period.
(7) A display panel that displays an image by causing a plurality of pixel portions to emit light, the pixel portion including a first driving transistor that supplies a first current from a drain to a source, and the first driving transistor. During the correction period in which the gate potential of the transistor is the signal potential of the video signal and the voltage between the gate and the source of the first driving transistor is corrected, the source potential of the first driving transistor is the first potential. The second driving transistor that supplies the second current from the drain to the source in response to the increase at a speed corresponding to the current of 1, and the source that is supplied from the source of the first driving transistor A table having a light emitting element that emits light with brightness according to the voltage corrected in the correction period by the first current and the second current supplied from the source of the second driving transistor. Apparatus.
(8) A first driving transistor, a second driving transistor, a switching transistor, a sampling transistor, a storage capacitor, and a light emitting element are included. One end of the storage capacitor is connected to the sampling from a signal line. In a state where a video signal is supplied via a transistor and the video signal is supplied to one end of the holding capacitor, a current is supplied from the first power source to the other end of the holding capacitor via the first driving transistor. And a correction period for correcting the voltage across the holding capacitor, and a first current supplied from the first power source via the first driving transistor according to the corrected voltage. The light emitting element is generated by a second current supplied from a second power source via the switching transistor and the second driving transistor in accordance with the corrected voltage. Driving circuit and a light emitting period to emit light.
(9) The drive circuit according to (8), wherein the switching transistor is turned off in the correction period.
(10) The drive circuit according to (8) or (9), wherein the first power source and the second power source are the same power source.
(11) A first drive transistor, a second drive transistor, a switching transistor, a sampling transistor, a storage capacitor, and a light emitting element are included, and one end of the storage capacitor is connected to the sampling from a signal line. In a state where a video signal is supplied via a transistor and the video signal is supplied to one end of the holding capacitor, a current is supplied from the first power source to the other end of the holding capacitor via the first driving transistor. And a correction period for correcting the voltage across the holding capacitor, and a first current supplied from the first power source via the first driving transistor according to the corrected voltage. The light emission by the second current supplied from the second power source via the switching transistor and the second driving transistor according to the corrected voltage Electronic device and a light emission period to emit light children.

  By the way, the organic EL panel 111 described above is also referred to as a panel module. A power supply circuit, an image LSI (Large Scale Integration), and the like are further added to the panel module to constitute a display device.

  A display device using an organic EL panel can be applied to an electronic apparatus such as a television receiver 171 having an organic EL panel 171a as shown in FIG. In addition to the television receiver 171, a digital still camera, a digital video camera, a notebook personal computer, a mobile phone, a television receiver, or the like can be used as the electronic device. In other words, the present disclosure can be applied to displays of electronic devices in various fields that display video signals input to these electronic devices or generated in the electronic devices as images or videos.

  The embodiments according to the present disclosure are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present disclosure.

  11 organic EL panel, 21 pixel array section, 31, 31 ′ pixel section, 41 data driver, 42, 42 ′ gate driver, 51-1-51-N DS driver, 52-1-52-N WS driver, 91 sampling Transistor, 92 driving transistor, 93 holding capacitor, 94 light emitting element, 95 auxiliary capacitor, 96 wiring, 97 EL element ELP, 111 organic EL panel, 131 DS driver, 151 switching transistor, 152 driving transistor, 171 television Receiver, 171a OLED panel

Claims (11)

A first driving transistor for supplying a first current from the drain to the source;
During the correction period in which the gate potential of the first driving transistor is set to the signal potential of the video signal and the voltage between the gate and the source of the first driving transistor is corrected, the first driving transistor A second driving transistor for supplying a second current from the drain to the source in response to the source potential rising at a rate corresponding to the first current;
The voltage corrected in the correction period by the first current supplied from the source of the first driving transistor and the second current supplied from the source of the second driving transistor. And a light-emitting element that emits light with brightness according to. A gate of the first driving transistor and a gate of the second driving transistor are connected;
The drive circuit according to claim 1, wherein a source of the first drive transistor and a source of the second drive transistor are connected. A switching element that is turned from an off state to an on state in response to the source potential of the first driving transistor rising at a speed corresponding to the first current in the correction period;
The second driving transistor supplies the second current from a drain connected to a power supply line through the switching element to a source in response to the switching element being turned on. The drive circuit according to 2. 4. The drive circuit according to claim 3, wherein the first drive transistor and the second drive transistor are arranged so that directions of a gate, a drain, and a source thereof coincide with each other. In a driving method of a driving circuit including a first driving transistor, a second driving transistor, and a light emitting element,
A first supply step of supplying a first current from a drain to a source by the first driving transistor;
During the correction period in which the gate potential of the first driving transistor is set to the signal potential of the video signal and the voltage between the gate and source of the first driving transistor is corrected by the second driving transistor. A second supply step of supplying a second current from the drain to the source in response to the source potential of the first driving transistor rising at a speed corresponding to the first current;
Due to the first current supplied from the source of the first driving transistor and the second current supplied from the source of the second driving transistor by the light emitting element, in the correction period. A light emitting step of emitting light at a brightness corresponding to the corrected voltage. A first driving transistor for supplying a first current from the drain to the source;
During the correction period in which the gate potential of the first driving transistor is set to the signal potential of the video signal and the voltage between the gate and the source of the first driving transistor is corrected, the first driving transistor A second driving transistor for supplying a second current from the drain to the source in response to the source potential rising at a rate corresponding to the first current;
The voltage corrected in the correction period by the first current supplied from the source of the first driving transistor and the second current supplied from the source of the second driving transistor. And a light emitting element that emits light with brightness according to the electronic device. Including a display panel that displays images by emitting light from a plurality of pixel portions;
The pixel portion is
A first driving transistor for supplying a first current from the drain to the source;
During the correction period in which the gate potential of the first driving transistor is set to the signal potential of the video signal and the voltage between the gate and the source of the first driving transistor is corrected, the first driving transistor A second driving transistor for supplying a second current from the drain to the source in response to the source potential rising at a rate corresponding to the first current;
The voltage corrected in the correction period by the first current supplied from the source of the first driving transistor and the second current supplied from the source of the second driving transistor. And a light emitting element that emits light at a brightness according to the display device. A first driving transistor;
A second driving transistor;
A switching transistor;
A sampling transistor;
Holding capacity,
Including a light emitting element and
One end of the holding capacitor is supplied with a video signal from a signal line through the sampling transistor,
In a state where the video signal is supplied to one end of the holding capacitor, a current is supplied from the first power source to the other end of the holding capacitor via the first driving transistor, and between the both ends of the holding capacitor. A correction period for correcting the voltage of
A first current supplied from the first power supply via the first driving transistor according to the corrected voltage, and a switching transistor and the first current from a second power supply according to the corrected voltage. And a light emitting period for causing the light emitting element to emit light by a second current supplied via the two driving transistors. The drive circuit according to claim 8, wherein the switching transistor is turned off in the correction period. The drive circuit according to claim 8, wherein the first power source and the second power source are the same power source. A first driving transistor;
A second driving transistor;
A switching transistor;
A sampling transistor;
Holding capacity,
Including a light emitting element and
One end of the holding capacitor is supplied with a video signal from a signal line through the sampling transistor,
In a state where the video signal is supplied to one end of the holding capacitor, a current is supplied from the first power source to the other end of the holding capacitor via the first driving transistor, and between the both ends of the holding capacitor. A correction period for correcting the voltage of
A first current supplied from the first power supply via the first driving transistor according to the corrected voltage, and a switching transistor and the first current from a second power supply according to the corrected voltage. An electronic device having a light emission period in which the light emitting element emits light by a second current supplied via the two driving transistors.

Images