JP2013186446A - Display panel, driving method thereof, display device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display panel capable of correcting variations between panels without using a dummy pixel or a luminance sensor, a driving method thereof, and a display device and an electronic apparatus including such a display panel.SOLUTION: A display panel includes plural luminous pixels arranged in matrix, and one or plural non-luminous pixels. The luminous pixel includes a luminous element, and a drive transistor for driving the luminous element. The non-luminous pixel does not include the luminous element, and includes a transistor with the same configuration as the drive transistor.

Description

  The present technology relates to a display panel including a light emitting element such as an organic EL (Electro Luminescence) element for each light emitting pixel and a driving method thereof. The present technology also relates to a display device and an electronic device that include the display panel.

  In recent years, in the field of display devices that perform image display, display devices that use current-driven light-emitting elements, such as organic EL elements, whose light emission luminance changes according to the value of a flowing current have been developed as light-emitting elements for pixels. Is being promoted. 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), so that it can be made thinner and brighter than a liquid crystal display device that requires a light source. .

  In general, the organic EL element is deteriorated by light emission, and the light emission efficiency is lowered and the drive voltage is raised. As a result, the light emission luminance of the organic EL element is lowered. In addition, the transistor built in the pixel circuit that drives the organic EL element also deteriorates when a negative bias is continuously applied to the gate-source voltage, causing a shift in threshold and a change in mobility. Since these fluctuation amounts vary greatly depending on the element characteristics, even if the light emission conditions and bias conditions are the same, the deterioration amounts may vary from panel to panel. Therefore, it has been proposed to use dummy pixels in order to correct variations between panels (see, for example, Patent Document 1).

JP 2011-128443 A

  By the way, when using a dummy pixel, the dummy pixel is caused to emit light, and its luminance is measured by a luminance sensor. However, in such a case, since it is necessary to cause the dummy pixel to emit light, power consumption increases. In addition, it is necessary to prevent light emitted from the dummy pixels from leaking to the outside, which limits the panel design. In addition, an IC for driving the dummy pixels is required separately. Furthermore, since a brightness sensor is used, the system becomes complicated and the cost increases. As described above, in the conventional method, various problems arise due to the use of dummy pixels and luminance sensors.

  The present technology has been made in view of such problems, and an object of the present technology is to provide a display panel capable of correcting variations between panels without using dummy pixels or luminance sensors, a driving method thereof, and such a method. It is an object of the present invention to provide a display device and an electronic device including a display panel.

  The display panel of the present technology includes a plurality of light emitting pixels arranged in a matrix and one or a plurality of non-light emitting pixels. The light emitting pixel includes a light emitting element and a driving transistor that drives the light emitting element. The non-light emitting pixel does not have a light emitting element and has a transistor having the same configuration as the driving transistor.

  The display device of the present technology includes the display panel and a drive circuit that drives the display panel.

  An electronic apparatus of the present technology includes the display device described above.

  In the display panel, the display device, and the electronic device of the present technology, one or a plurality of non-light emitting pixels are provided in addition to the plurality of light emitting pixels arranged in a matrix. The non-light emitting pixel is not provided with a light emitting element, and is provided with a transistor having the same configuration as the driving transistor included in the light emitting pixel. Accordingly, for example, it is possible to measure a current flowing through a transistor included in a non-light emitting pixel or a physical quantity corresponding to the current and correct the video signal using the measurement result.

  The display panel driving method of the present technology is a driving method of a display panel including a plurality of light emitting pixels arranged in a matrix and one or a plurality of non-light emitting pixels. In a display panel to which this driving method is applied, the light emitting pixel has a light emitting element and a driving transistor for driving the light emitting element, and the non-light emitting pixel has no light emitting element and is the same as the driving transistor. A correcting transistor having the configuration is included. The display panel drive method of the present technology includes a step of measuring the current flowing through the correction transistor or the physical quantity corresponding thereto in the display panel having such a configuration, and correcting the video signal using the measurement result. Contains.

  In the display panel driving method of the present technology, in a display panel provided with one or a plurality of non-light-emitting pixels in addition to the plurality of light-emitting pixels arranged in a matrix, the correction transistor included in the non-light-emitting pixels flows. The current or the physical quantity corresponding to the current is measured, and the video signal is corrected using the measurement result.

  According to the display panel, the display device, and the electronic device of the present technology, it is possible to measure the current flowing through the transistor included in the non-light-emitting pixel or a physical quantity corresponding thereto, and correct the video signal using the measurement result. As a result, variations between panels can be corrected without using dummy pixels or luminance sensors.

  According to the display panel driving method of the present technology, the current flowing through the transistor included in the non-light emitting pixel or the physical quantity corresponding thereto is measured, and the video signal is corrected using the measurement result. And variations between panels can be corrected without using a brightness sensor.

It is a figure showing an example of the composition of the display concerning an embodiment of this art. It is a figure showing the other example of a structure of the display apparatus of FIG. It is a figure showing an example of the circuit structure of the light emission pixel of FIG. 1, FIG. It is a figure showing an example of the circuit structure of the non-light-emitting pixel of FIG. 1, FIG. It is a figure showing the other example of a circuit structure of the non-light-emitting pixel of FIG. 1, FIG. FIG. 3 is a diagram illustrating another example of the circuit configuration of the non-light emitting pixel in FIGS. 1 and 2. It is a figure showing an example of the connection mode of each pixel and wiring when a non-light-emitting pixel has the circuit configuration shown in FIGS. FIG. 6 is a diagram illustrating another example of a connection mode between each pixel and a wiring when a non-light-emitting pixel has the circuit configuration illustrated in FIGS. 4 and 5. It is a figure showing an example of the connection mode of each pixel and wiring when a non-light-emitting pixel has the circuit configuration shown in FIG. It is a figure showing the other example of the connection mode of each pixel and wiring of each pixel when a non-light-emitting pixel has the circuit configuration shown in FIG. FIG. 3 is a diagram illustrating an example of a circuit configuration of a display control circuit in FIGS. 1 and 2. It is a figure showing an example of the table contained in the memory of FIG. FIG. 3 is a diagram illustrating an example of a circuit configuration of a measurement circuit in FIGS. 1 and 2. It is a figure showing the modification of a structure of the display apparatus of FIG. It is a figure showing the other example of a structure of the display apparatus of FIG. FIG. 16 is a diagram illustrating an example of a circuit configuration of the measurement circuit in FIGS. 14 and 15. It is a figure showing the modification of a structure of the display apparatus of FIG. FIG. 18 is a diagram illustrating another example of the configuration of the display device in FIG. 17. FIG. 19 is a diagram illustrating a modification of the circuit configuration of the light emitting pixel in FIGS. 1, 2, 14, 15, 17, and 18. FIG. 19 is a diagram illustrating a modification of the circuit configuration of the non-light-emitting pixels in FIGS. 1, 2, 14, 15, 17, and 18. FIG. 19 is a diagram illustrating another modification of the circuit configuration of the non-light-emitting pixel in FIGS. 1, 2, 14, 15, 17, and 18. It is a perspective view showing the external appearance of the application example 1 of the said display apparatus. (A) is a perspective view showing the external appearance seen from the front side of the application example 2 of the said display apparatus, (B) is a perspective view showing the external appearance seen from the back side. It is a perspective view showing the external appearance of the example 3 of application of the said display apparatus. It is a perspective view showing the external appearance of the application example 4 of the said display apparatus. (A) is the front view of the application example 5 of the said display apparatus in the open state, (B) is the side view, (C) is the front view of the closed state, (D) is a left side view, (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 (display device)
2. Modified example (display device)
3. Application example (electronic equipment)

<1. Embodiment>
[Constitution]
FIG. 1 illustrates a schematic configuration of a display device 1 according to an embodiment of the present technology. The display device 1 includes a display panel 10 and a drive circuit 20 that drives the display panel 10 based on a video signal 20A and a synchronization signal 20B input from the outside. The drive circuit 20 includes, for example, a display control circuit 21, a signal line drive circuit 22, a write line drive circuit 23, a power supply line drive circuit 24, and a measurement circuit 25.

(Display panel 10)
The display panel 10 includes a plurality of light emitting pixels 11 and one or a plurality of non-light emitting pixels 14 arranged in a matrix. FIG. 1 illustrates a case where one non-light emitting pixel 14 is provided in the display panel 10. The display panel 10 displays an image based on the video signal 20 </ b> A input from the outside as each light emitting pixel 11 is driven in an active matrix by the drive circuit 20. That is, in the display panel 10, an area where each light emitting pixel 11 is arranged is a display area 10 </ b> A that performs video display. In the display panel 10, the periphery of the display area 10A is covered with a light shielding member. Therefore, the frame region 10B corresponding to the periphery of the display region 10A is a non-display region where no video is displayed on the display panel 10.

  By the way, the display panel 10 is configured to drive one or a plurality of non-light emitting pixels 14 together with each light emitting pixel 11 in an active matrix. For example, one or a plurality of non-light emitting pixels 14 are arranged in the display area 10A. However, the non-light emitting pixels 14 do not contribute to image display because they do not have the organic EL elements 13 described later. Note that the non-light emitting pixels 14 may be arranged in the frame region 10B, for example, as illustrated in FIG.

  Here, the video signal 20 </ b> A is, for example, a digital signal of video displayed on the display panel 10 for each field, and includes a digital signal for each light emitting pixel 11. The light emitting pixel 11 corresponds to a minimum unit point constituting a screen on the display panel 10. When the display panel 10 is a color display panel, the light emitting pixels 11 correspond to subpixels that emit light of a single color such as red, green, or blue, and when the display panel 10 is a monochrome display panel, The light emitting pixel 11 corresponds to a pixel that emits monochromatic light (white light).

  FIG. 3 illustrates an example of a circuit configuration of the light emitting pixel 11. The light emitting pixel 11 includes, for example, a pixel circuit 12 and an organic EL element 13. The organic EL element 13 has, for example, a configuration in which an anode electrode, an organic layer, and a cathode electrode are sequentially stacked.

  For example, the pixel circuit 12 includes a drive transistor Tr1, a write transistor Tr2, and a storage capacitor Cs, and has a circuit configuration of 2Tr1C. The write transistor Tr2 controls application of a signal voltage corresponding to the video signal 20A to the gate of the drive transistor Tr1. Specifically, the write transistor Tr2 samples a voltage of a signal line DTL described later and writes it to the gate of the drive transistor Tr1. The drive transistor Tr1 drives the organic EL element 13. Specifically, the drive transistor Tr1 controls the current flowing through the organic EL element 13 in accordance with the magnitude of the voltage written by the write transistor Tr2. The holding capacitor Cs holds a predetermined voltage between the gate and source of the driving transistor Tr1. Note that the pixel circuit 12 may have a circuit configuration different from the above-described 2Tr1C circuit configuration.

  The drive transistor Tr1 and the write transistor Tr2 are, 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). The drive transistor Tr1 or the write transistor Tr2 may be a p-channel MOS type TFT. Further, the material of the TFT is not particularly limited. The TFT may be, for example, a low-temperature polysilicon TFT or an oxide TFT.

  The display panel 10 further includes a plurality of write lines WSL extending in the row direction, a plurality of signal lines DTL extending in the column direction, and a plurality of power supply lines DSL extending in the row direction. Yes. The write line WSL supplies a scanning signal. The power supply line DSL supplies a current for driving the organic EL element 13. The signal line DTL supplies a signal voltage corresponding to the video signal 20A. A light emitting pixel 11 is provided in the vicinity of an intersection between the signal line DTL and the writing line WSL. Each signal line DTL is connected to the output end (not shown) of the signal line drive circuit 22 and the source or drain of the write transistor Tr2. Each write line WSL is connected to the output terminal (not shown) of the write line drive circuit 23 and the gate of the write transistor Tr2. Each power supply line DSL is connected to the output end (not shown) of the power supply line drive circuit 24 and the source or drain of the drive transistor Tr1.

  The gate of the write transistor Tr2 is connected to the write line WSL. The source or drain of the write transistor Tr2 is connected to the signal line DTL, and the terminal not connected to the signal line DTL among the source and drain of the write transistor Tr2 is connected to the gate of the drive transistor Tr1. The source or drain of the drive transistor Tr1 is connected to the power supply line DSL, and the terminal not connected to the power supply line DSL among the source and drain of the drive transistor Tr1 is connected to the anode of the organic EL element 13. One end of the storage capacitor Cs is connected to the gate of the drive transistor Tr1, and the other end of the storage capacitor Cs is connected to the source of the drive transistor Tr1 (terminal on the organic EL element 13 side in FIG. 3). That is, the storage capacitor Cs is inserted between the gate and source of the drive transistor Tr1. The organic EL element 13 has an element capacitance Coled.

  The display panel 10 further includes a ground line GND connected to the cathode of the organic EL element 13, as shown in FIG. The ground line GND is connected to an external circuit having a ground potential. The ground line GND is constituted by, for example, a strip-like electrode formed in a strip shape corresponding to the pixel column.

  FIG. 4 illustrates an example of a circuit configuration of the non-light emitting pixel 14. The non-light-emitting pixel 14 has a configuration in which, for example, a diode-connected transistor Tr3 is provided instead of the organic EL element 13 in the light-emitting pixel 11. The transistor Tr3 is a transistor having the same configuration as that of the drive transistor Tr1, and is, for example, an n-channel MOS type TFT. When the driving transistor Tr1 is a p-channel MOS type TFT, the transistor Tr3 may also be a p-channel MOS type TFT. That is, the non-light emitting pixel 14 does not have the organic EL element 13 and has a transistor having the same configuration as that of the driving transistor Tr1.

  In the non-light emitting pixel 14, a terminal not connected to the driving transistor Tr1 among the source and drain of the transistor Tr3 is connected to the cathode line CTL. The cathode line CTL is composed of strip-like electrodes formed in a strip shape corresponding to the pixel columns, and is connected to an input end (not shown) of the measurement circuit 25.

  In the non-light emitting pixel 14, the transistor Tr3 can be omitted as necessary, for example, as shown in FIG. Further, in the non-light emitting pixel 14, the writing transistor Tr2 and the storage capacitor Cs can be omitted as necessary as shown in FIG. 6, for example. Note that the connection between the non-light-emitting pixel 14 and the write line WSL in the case where the non-light-emitting pixel 14 has the configuration shown in FIGS. 4 and 5 and the case where the non-light-emitting pixel 14 has the configuration shown in FIG. The aspect changes. Therefore, in the following, a connection mode when the non-light-emitting pixel 14 has the configuration shown in FIGS. 4 and 5 will be described first, and then the non-light-emitting pixel 14 has the configuration shown in FIG. A connection mode in the case of being configured will be described.

  7A and 7B show an example of a connection mode when the non-light emitting pixel 14 has the configuration shown in FIGS. 4 and 5. As described above, each light emitting pixel 11 is disposed in the vicinity of the intersection of the signal line DTL and the write line WSL. Each light emitting pixel 11 is connected to a common write line WSL and power supply line DSL for each pixel row, and is connected to a common signal line DTL for each pixel column. On the other hand, the non-light emitting pixels 14 are arranged following the arrangement of the light emitting pixels 11. Specifically, the non-light emitting pixels 14 are arranged following the arrangement of the light emitting pixels 11 in the row direction, and are connected to a writing line WSL common to the light emitting pixels 11 adjacent to the non-light emitting pixels 14. Further, the non-light emitting pixels 14 are connected to a power supply line DSL common to the light emitting pixels 11 adjacent to the non-light emitting pixels 14. That is, the total number of the write lines WSL and the power supply lines DSL is not changed by providing the non-light emitting pixels 14. The non-light emitting pixels 14 are connected to a signal line DTL different from the light emitting pixels 11 adjacent to the non-light emitting pixels 14. Therefore, the total number of signal lines DTL is increased by one by providing the non-light emitting pixels 14.

  FIGS. 8A and 8B show other examples of connection modes in the case where the non-light emitting pixel 14 has the configuration shown in FIGS. 4 and 5. Here, the non-light emitting pixels 14 are arranged following the arrangement of the light emitting pixels 11 in the column direction, and are connected to a signal line DTL common to the light emitting pixels 11 adjacent to the non-light emitting pixels 14. That is, the total number of signal lines DTL does not change due to the provision of the non-light emitting pixels 14. Note that the non-light emitting pixels 14 are connected to a writing line WSL and a power supply line DSL that are different from those of the light emitting pixels 11 adjacent to the non-light emitting pixels 14. Therefore, by providing the non-light emitting pixels 14, the total number of the write lines WSL and the power supply lines DSL is increased by one each.

  9A and 9B show an example of a connection mode in the case where the non-light emitting pixel 14 has the configuration shown in FIG. As described above, each light emitting pixel 11 is disposed in the vicinity of the intersection of the signal line DTL and the write line WSL. Each light emitting pixel 11 is connected to a common write line WSL and power supply line DSL for each pixel row, and is connected to a common signal line DTL for each pixel column. On the other hand, the non-light emitting pixels 14 are arranged following the arrangement of the light emitting pixels 11. Specifically, the non-light emitting pixels 14 are arranged following the arrangement of the light emitting pixels 11 in the row direction, and are connected to a power supply line DSL common to the light emitting pixels 11 adjacent to the non-light emitting pixels 14. That is, the total number of power supply lines DSL is not changed by providing the non-light emitting pixels 14. Note that the non-light-emitting pixels 14 are not connected to the write line WSL. Further, the non-light emitting pixels 14 are connected to a signal line DTL different from the light emitting pixels 11 adjacent to the non-light emitting pixels 14. Therefore, the total number of signal lines DTL is increased by one by providing the non-light emitting pixels 14.

  FIGS. 10A and 10B show other examples of connection modes in the case where the non-light-emitting pixels 14 have the configuration shown in FIG. Here, the non-light emitting pixels 14 are arranged following the arrangement of the light emitting pixels 11 in the column direction, and are connected to a signal line DTL common to the light emitting pixels 11 adjacent to the non-light emitting pixels 14. That is, the total number of signal lines DTL does not change due to the provision of the non-light emitting pixels 14. Note that the non-light-emitting pixels 14 are not connected to the write line WSL. Further, the non-light emitting pixels 14 are connected to a power supply line DSL different from that of the light emitting pixels 11 adjacent to the non-light emitting pixels 14. For this reason, the total number of power supply lines DSL is increased by one by providing the non-light emitting pixels 14.

(Drive circuit 20)
Next, the drive circuit 20 will be described. As described above, the drive circuit 20 includes the display control circuit 21, the signal line drive circuit 22, the write line drive circuit 23, the power supply line drive circuit 24, and the measurement circuit 25, for example. The display control circuit 21 includes, for example, a conversion circuit 31, a controller 32, and a memory 33 as shown in FIG.

  The memory 33 stores, for example, a table 33A as shown in FIG. The table 33A corresponds to, for example, a description of the relationship between the current I and the correction coefficient α as shown in FIG. Here, the current I is compared with the current value measured by the measurement circuit 25. The correction coefficient α is for correcting the light emission luminance of the light emitting pixel 11 that varies due to the deterioration of the element characteristics of the drive transistor Tr1 in the light emitting pixel 11. By performing a predetermined calculation on the video signal 20A using the correction coefficient α, it is possible to obtain the video signal 20A in which deterioration of element characteristics of the drive transistor Tr1 is taken into consideration.

  For example, the controller 32 controls the control signals 32A, 21B, which control the operation timing of the conversion circuit 31, the signal line drive circuit 22, the write line drive circuit 23, and the power supply line drive circuit 24 from the synchronization signal 20B supplied from the outside. 21C and 21D are generated. Examples of the synchronization signal 20B include a vertical synchronization signal, a horizontal synchronization signal, and a dot clock signal.

  The controller 32 corrects the video signal 20A using the measurement signal 25A input from the measurement circuit 25 and the table 33A. The controller 32 includes the corrected video signal 20 </ b> A in the control signal 21 </ b> C and outputs it to the write line drive circuit 23.

  The conversion circuit 31 includes, for example, a frame memory, a write circuit, a read circuit, and a decoder. The frame memory is a video display memory having a storage capacity that is at least larger than the resolution of the display area 10A. For example, the row address, the column address, and the gradation of each light emitting pixel 11 associated with the row address and the column address. Data can be stored. The writing circuit uses the synchronization signal 20B to generate a write address of the video signal 20A and outputs it to the frame memory in synchronization with the synchronization signal 20B. The write address includes, for example, a row address and a column address. The read circuit generates a read address based on the control signal 32A and outputs it to the frame memory. The decoder outputs the gradation data output from the frame memory as signal data 21A.

  For example, the signal line driving circuit 22 applies an analog signal voltage corresponding to the signal data 21A input from the conversion circuit 31 to each signal line DTL in response to the input of the control signal 21B. The signal line drive circuit 22 can output, for example, two types of voltages (Vofs, Vsig). For example, the signal line driving circuit 22 supplies two types of voltages (Vofs, Vsig) to the light emitting pixels 11 or the non-light emitting pixels 14 selected by the writing line driving circuit 23 via the signal line DTL. ing. Here, Vsig is a signal voltage corresponding to the video signal 20A. Vofs is a constant voltage unrelated to the video signal 20A. The minimum voltage of Vsig is a voltage value lower than Vofs, and the maximum voltage of Vsig is a voltage value higher than Vofs.

  The write line drive circuit 23 writes a scan pulse for selecting each light emitting pixel 11 (and non-light emitting pixel 14) in a predetermined unit (for example, row unit) based on the address data specified from the control signal 21C. It outputs to the incoming line WSL. For example, the write line drive circuit 23 sequentially selects a plurality of write lines WSL for each predetermined unit (for example, row unit) in accordance with the input of the control signal 21C. The write line drive circuit 23 can output, for example, two types of voltages (Von, Voff). The write line drive circuit 23 supplies, for example, two types of voltages (Von, Voff) to the light emitting pixel 11 or the non-light emitting pixel 14 to be driven via the write line WSL, and controls the on / off of the write transistor Tr2. Is supposed to do. Here, Von has a value equal to or higher than the ON voltage of the write transistor Tr2. The off voltage Voff is lower than the on voltage of the write transistor Tr2.

  For example, the power supply line driving circuit 24 sequentially selects a plurality of power supply lines DSL for each predetermined unit (for example, for each row) in accordance with the input of the control signal 21D. The power line drive circuit 24 can output, for example, two types of voltages (Vcc, Vss). For example, the power supply line driving circuit 24 supplies two types of voltages (Vcc, Vss) to the light emitting pixels 11 or the non-light emitting pixels 14 selected by the writing line driving circuit 23 via the power supply line DSL. ing. Here, Vss is a voltage value lower than a voltage (Vel + Vcath) obtained by adding the threshold voltage Vel of the organic EL element 13 and the cathode voltage Vcath of the organic EL element 13. Vcc is a voltage value equal to or higher than the voltage (Vel + Vcath).

  The measurement circuit 25 measures the current flowing through the drive transistor Tr1 included in the non-light emitting pixel 14. For example, as shown in FIG. 13, the measurement circuit 25 includes an ammeter, and outputs a current value of the cathode line CTL measured by the ammeter as a measurement signal 25A.

  Note that the measurement circuit 25 may measure a physical quantity corresponding to the current flowing through the driving transistor Tr1 included in the non-light emitting pixel 14. For example, the measurement circuit 25 may be configured to include a voltmeter and output a voltage value measured by the voltmeter as the measurement signal 25A. The voltage value is, for example, the source-drain voltage of the drive transistor Tr1. The measurement circuit 25 may output a measurement value measured by an ammeter or a voltmeter as a measurement signal 25A. However, the measurement circuit 25 can obtain the measurement value by performing a predetermined calculation on the measurement value. The obtained value may be output as the measurement signal 25A.

[Operation]
Next, an example of operation | movement of the display apparatus 1 of this Embodiment is demonstrated.

  In the display device 1, a signal voltage (voltage Vsig) corresponding to the video signal 20A is applied to each signal line DTL by the signal line driving circuit 22, and a selection pulse corresponding to the control signal 21A is applied to the writing line driving circuit 24 and The power supply line drive circuit 24 sequentially applies the plurality of write lines WSL and power supply lines DSL. Thereby, the pixel circuit 12 is controlled to be turned on / off in each light emitting pixel 11, and a driving current is injected into the organic EL element 13 of each light emitting pixel 11, whereby holes and electrons are recombined, and light emission occurs. Light is extracted outside. As a result, an image is displayed in the display area 10 </ b> A of the display panel 10.

  Further, in the display device 1, the measurement circuit 25 measures the current flowing through the drive transistor Tr included in the non-light emitting pixel 14 or the physical quantity corresponding thereto. Then, the video signal 20A is corrected using the measurement result. Specifically, a predetermined calculation is performed on the video signal 20A using the measurement signal 25A obtained by the measurement circuit 25 and the table 33A in the memory 33. As a result, a video signal 20A in which deterioration of element characteristics of the drive transistor Tr1 is taken into consideration is obtained. As a result, display quality deterioration due to deterioration of element characteristics of the drive transistor Tr1 is reduced.

[effect]
Next, the effect in the display apparatus 1 of this Embodiment is demonstrated.

  In general, the organic EL element is deteriorated by light emission, and the light emission efficiency is lowered and the drive voltage is raised. As a result, the light emission luminance of the organic EL element is lowered. In addition, the transistor built in the pixel circuit that drives the organic EL element also deteriorates when a negative bias is continuously applied to the gate-source voltage, causing a shift in threshold and a change in mobility. Since these fluctuation amounts vary greatly depending on the element characteristics, even if the light emission conditions and bias conditions are the same, the deterioration amounts may vary from panel to panel. For this reason, dummy pixels have been conventionally used to correct variations between panels.

  By the way, when using a dummy pixel, the dummy pixel is caused to emit light, and its luminance is measured by a luminance sensor. However, in such a case, since it is necessary to cause the dummy pixel to emit light, power consumption increases. In addition, it is necessary to prevent light emitted from the dummy pixels from leaking to the outside, which limits the panel design. In addition, an IC for driving the dummy pixels is required separately. Furthermore, since a brightness sensor is used, the system becomes complicated and the cost increases. As described above, in the conventional method, various problems arise due to the use of dummy pixels and luminance sensors.

  On the other hand, in the present embodiment, in addition to the plurality of light emitting pixels 11 arranged in a matrix, one or a plurality of non-light emitting pixels 14 are provided. The non-light emitting pixel 14 is not provided with the organic EL element 13, and is provided with a transistor having the same configuration as the driving transistor Tr 1 included in the light emitting pixel 11. Accordingly, it is possible to measure the current flowing through the transistor included in the non-light emitting pixel 14 or the physical quantity corresponding thereto, and correct the video signal 20A using the measurement result. As a result, the video signal 20A in which the deterioration of the element characteristics of the drive transistor Tr1 is taken into consideration can be obtained, so that the display quality deterioration due to the deterioration of the element characteristics of the drive transistor Tr1 can be reduced. Therefore, variations between panels can be corrected.

  By the way, in the present embodiment, dummy pixels and luminance sensors are not used, and the non-light emitting pixels 14 are arranged following the arrangement of the light emitting pixels 11. Therefore, there are no problems such as an increase in power consumption, panel design restrictions, addition of IC, system complexity, and cost increase as in the case of using dummy pixels or a luminance sensor. From the above, in this embodiment, variations between panels can be corrected without using dummy pixels or luminance sensors.

<2. Modification>
[Modification 1]
In the above embodiment, the measurement circuit 25 is inserted into the cathode line CTL. However, for example, as shown in FIGS. 14 and 15, it may be inserted into the power supply line DSL. In such a case, the measurement circuit 25 outputs the current value of the power supply line DSL measured by the ammeter as the measurement signal 25A as shown in FIG. Here, the current value measured by the measurement circuit 25 is equivalent to the current flowing through the drive transistor Tr <b> 1 included in the non-light emitting pixel 14. Therefore, even in such a case, variations between panels can be corrected.

  Note that in order for the measurement circuit 25 to be inserted into the power supply line DSL, it is necessary that the power supply line DSL has a margin enough to allow the measurement circuit 25 to be inserted into the power supply line DSL. If the power line drive circuit 24 and the display panel 10 are connected by FPC (Flexible printed circuits), it is necessary that the above-described margin exists in the FPC. However, if the above-described margin does not exist in the FPC, for example, as illustrated in FIGS. 17 and 18, one or more power supply lines DSL connected to the non-light emitting pixels 14 are separately provided from the display panel 10. Alternatively, an FPC to be drawn out may be provided, and the measurement circuit 25 may be provided in the FPC.

[Modification 2]
Although the case where the light emitting pixel 11 has a 2Tr1C circuit configuration has been exemplified in the above embodiment and Modification 1, the circuit configuration may be other than that. For example, as shown in FIG. 19, the light emitting pixel 11 may include a pixel circuit 12 including six transistors (Tr1, Tr2, Tr4, Tr5, Tr6, Tr7). Similarly, for example, as illustrated in FIGS. 20 and 21, the non-light emitting pixel 14 includes a pixel circuit 12 including six transistors (Tr1, Tr2, Tr4, Tr5, Tr6, Tr7). Also good.

<3. Application example>
Hereinafter, application examples of the display device 1 described in the above embodiment and the modifications thereof will be described. The display device 1 according to the above-described embodiment or the like receives a video signal input from the outside or a video signal generated inside, such as a television device, a digital camera, a notebook personal computer, a mobile terminal device such as a mobile phone, or a video camera. The present invention can be applied to display devices of electronic devices in various fields that display as images or videos.

(Application example 1)
FIG. 22 illustrates an appearance of a television device to which the display device 1 according to the above-described embodiment or the like is applied. This television apparatus has, for example, a video display screen unit 300 including a front panel 310 and a filter glass 320, and the video display screen unit 300 is configured by the display device 1 according to the above-described embodiment or the like. .

(Application example 2)
FIG. 23 illustrates an appearance of a digital camera to which the display device 1 according to the above-described embodiment or the like 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-described embodiment or the like. Yes.

(Application example 3)
FIG. 24 illustrates an appearance of a notebook personal computer to which the display device 1 according to the above-described embodiment or the like is applied. The notebook personal computer includes, 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 device such as the above-described embodiment. 1.

(Application example 4)
FIG. 25 illustrates an appearance of a video camera to which the display device 1 according to the above-described embodiment or the like 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 the above-described embodiment or the like.

(Application example 5)
FIG. 26 illustrates an appearance of a mobile phone to which the display device 1 according to the above-described embodiment and the like 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 the above-described embodiment or the like.

  As described above, the present technology has been described with reference to the embodiment and its modified examples and application examples, but the present technology is not limited to the above-described embodiment and the like, and various modifications are possible.

  For example, in the above embodiment and the like, the configuration of the pixel circuit 12 for active matrix driving is not limited to that described in the above embodiment and the like, and a capacitor and a transistor may be added as necessary. In that case, in addition to the display control circuit 21, the signal line drive circuit 22, the write line drive circuit 23, the power supply line drive circuit 24, the measurement circuit 25, and the like according to the change of the pixel circuit 12, necessary drive is performed. A circuit may be added.

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 10 ... Display panel, 10A ... Display area, 10B ... Frame area, 11 ... Light-emitting pixel, 12 ... Pixel circuit, 13 ... Organic EL element, 14 ... Non-light-emitting pixel, 20 ... Drive circuit, 20A ... Video signal, 20B ... Synchronization signal, 21 ... Display control circuit, 21A ... Signal data, 21B, 21C, 21D, 32A ... Control signal, 22 ... Signal line drive circuit, 23 ... Write line drive circuit, 24 ... Power line drive Circuit 24 ... Measurement circuit 25A ... Measurement signal 31 ... Conversion circuit 32 ... Controller 33 ... Memory 33A ... Table 300 ... Video display screen part 310 ... Front panel 320 ... Filter glass 410 ... Light emission part 420, 530, 640 ... display section, 430 ... menu switch, 440 ... shutter button, 510 ... main body, 520 ... keyboard, 610 ... main body section 620 ... Lens, 630 ... Start / Stop switch, 710 ... Upper housing, 720 ... Lower housing, 730 ... Connection part, 740 ... Display, 750 ... Sub-display, 760 ... Picture light, 770 ... Camera, Coled ... Element Capacitance, Cs: Retention capacitance, CTL: Cathode line, DTL: Signal line, DSL ... Power supply line, Ids ... Current, Vcc, Vofs, Von, Voff, Vsig, Vss ... Voltage, Vg ... Gate voltage, Vgs ... Gate-source Inter-voltage, Vs ... source voltage, Tr1 ... drive transistor, Tr2 ... write transistor, Tr3-Tr7 ... transistor, WSL ... write line, .alpha .... correction coefficient.

Claims (9)

A plurality of light emitting pixels arranged in a matrix;
One or more non-light emitting pixels,
The light-emitting pixel includes a light-emitting element and a driving transistor that drives the light-emitting element,
The non-light emitting pixel does not have the light emitting element and has a transistor having the same configuration as the driving transistor. The display panel according to claim 1, wherein the one or more non-light emitting pixels are arranged following the arrangement of the light emitting pixels. A plurality of first wirings extending in the column direction and supplying a signal voltage corresponding to the video signal;
The display panel according to claim 2, wherein the non-light-emitting pixels are arranged following the arrangement of the light-emitting pixels in the column direction, and are connected to a first wiring common to the light-emitting pixels adjacent to the non-light-emitting pixels. A plurality of second wirings extending in a row direction and supplying a current for driving the light emitting element;
The display panel according to claim 2, wherein the non-light emitting pixels are arranged following the arrangement in the row direction of the light emitting pixels and are connected to a second wiring common to the light emitting pixels adjacent to the non-light emitting pixels. A plurality of third wirings extending in the row direction and supplying a scanning signal;
The display panel according to claim 4, wherein the non-light emitting pixel is connected to a third wiring common to the light emitting pixel adjacent to the non-light emitting pixel. A display panel and a drive circuit for driving the display panel;
The display panel includes a plurality of light emitting pixels arranged in a matrix and one or a plurality of non-light emitting pixels,
The light-emitting pixel includes a light-emitting element and a driving transistor that drives the light-emitting element,
The non-light emitting pixel does not include the light emitting element, and includes a correction transistor having the same configuration as the driving transistor. The display panel includes a measurement circuit that measures a current flowing through the correction transistor or a physical quantity corresponding to the current.
The display device according to claim 6, wherein the drive circuit corrects the video signal using a measurement result of the measurement circuit. A display device,
The display device includes a display panel and a drive circuit that drives the display panel,
The display panel includes a plurality of light emitting pixels arranged in a matrix and one or a plurality of non-light emitting pixels,
The light-emitting pixel includes a light-emitting element and a driving transistor that drives the light-emitting element,
The non-light emitting pixel does not include the light emitting element, and includes a correction transistor having the same configuration as the driving transistor. A plurality of light-emitting pixels arranged in a matrix, and one or a plurality of non-light-emitting pixels, and the light-emitting pixels include a light-emitting element and a drive transistor that drives the light-emitting element, and the non-light-emitting pixel In a display panel that does not have the light emitting element and has a correction transistor having the same configuration as the drive transistor, the current flowing through the correction transistor or a physical quantity corresponding thereto is measured, and the measurement result is used. A display panel driving method including a step of correcting a video signal.

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