JP2005173184A - Display device and method for controlling drive of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device and its drive controlling method by which each light emitting element can be allowed to emit light at a suitable luminance gradation corresponding to display data independently of the deterioration or dispersion of light emitting characteristics of respective display pixels due to changes in external environments or secular change and image information can be effectively displayed. <P>SOLUTION: The display device 100 is provided with at least a display panel 110 on which a plurality of display pixels are arrayed like a matrix, a light guide plate 140 arranged on the rear side of the display panel 110, a light receiving sensor part 150 stuck to the side end face of the light guide plate 140 and capable of detecting specific quantity corresponding to the light emitting characteristic of each display pixel, a correction control circuit 160 for correcting display data so as to maintain the light emitting characteristic of each display pixel at a fixed state, and a data driver 130 for setting gradation signal voltage Vdata to be supplied to each display pixel on the basis of the corrected display data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display device and a drive control method thereof, and in particular, a current control type (or current drive type) light emitting element that emits light at a predetermined luminance gradation by supplying a drive current according to display data. The present invention relates to a display device including a plurality of arrayed display panels (pixel arrays) and a drive control method thereof.

  In recent years, organic electroluminescence elements (hereinafter abbreviated as “organic EL elements”) are being used as next-generation display devices (displays) following liquid crystal display devices (LCDs) that are widely used as monitors and displays for personal computers and video equipment. And an inorganic electroluminescent element (hereinafter abbreviated as “inorganic EL element”) or a self-luminous optical element (light emitting element) such as a light emitting diode (LED) is provided in a two-dimensional array. Research and development for full-scale practical application of light emitting element type displays has been actively conducted.

  In particular, a light-emitting element type display using an active matrix driving method has a faster display response speed, no viewing angle dependency, higher luminance and higher contrast, and higher display image quality than liquid crystal display devices. In addition to being able to achieve finer and lower power consumption, it does not require a backlight unlike a liquid crystal display device, and thus has an extremely advantageous feature that it can be made thinner and lighter.

  In such a light emitting element type display, various drive control mechanisms and control methods for controlling the operation (light emission state) of the light emitting element have been proposed. For example, as described in Patent Document 1, Patent Document 2, and the like, each display pixel constituting the display panel includes a plurality of light emitting elements for driving and controlling the light emitting state of the light emitting element in addition to the light emitting element. 2. Description of the Related Art A configuration including a drive circuit composed of switching elements (hereinafter referred to as a “light emission drive circuit” for the sake of convenience and equivalent to a “pixel drive circuit” described later) is known.

FIG. 22 is an equivalent circuit diagram illustrating a configuration example of a main part of each display pixel of a light emitting element type display including an organic EL element according to a conventional technique.
As shown in FIG. 22A, the display pixel described in Patent Document 1 is near each intersection of a plurality of scanning lines SL and data lines DL arranged in a matrix on a display panel (not shown). A thin film transistor (TFT) Tr61 whose gate terminal is connected to the scanning line SL, whose source terminal and drain terminal are connected to the data line DL and the contact N61, and whose gate terminal is the contact N61 and whose source terminal (S) is the ground potential Vgnd. A light emitting drive circuit DP1 having a connected thin film transistor Tr62, and an anode terminal connected to the drain terminal (D) of the thin film transistor Tr62 provided in the light emission drive circuit DP1, and a cathode terminal lower than the ground potential Vgnd It has an organic EL element OEL connected to a constant power supply voltage (low potential power supply) Vss composed of a negative voltage. That.

In FIG. 22A, CP1 is a parasitic capacitance (retention capacitance) formed between the gate and source of the thin film transistor Tr62. The thin film transistor Tr61 is formed of an n-channel field effect transistor, and the thin film transistor Tr62 is formed of a p-channel field effect transistor.
In the light emission drive circuit DP1 having such a configuration, as shown below, two field effect transistors (switching means) composed of thin film transistors Tr61 and Tr62 are controlled to be turned on and off at a predetermined timing. The organic EL element OEL is controlled to emit light.

  That is, in the light emission drive circuit DP1, when the high-level scanning signal Vsel is applied to the scanning line SL to set the display pixel to a selected state, the thin film transistor Tr61 is turned on. ) Is applied to the gate terminal (contact N61) of the thin film transistor Tr62 through the thin film transistor Tr61. As a result, the thin film transistor Tr62 is turned on in a conductive state corresponding to the gradation signal voltage Vpix, and a predetermined light emission drive current flows from the ground potential Vgnd through the thin film transistor Tr62 in the direction of the constant power supply voltage Vss. Emits light with a luminance gradation corresponding to the display data (gradation signal voltage Vpix).

Next, when the low-level scanning signal Vsel is applied to the scanning line SL to set the display pixel to a non-selected state, the thin film transistor Tr61 is turned off, thereby electrically disconnecting the data line DL and the light emission driving circuit DP1. The As a result, the voltage applied to the gate terminal of the thin film transistor Tr62 is held by the parasitic capacitance CP1, and the thin film transistor Tr62 is maintained in the on state. The ground potential Vgnd is applied to the organic EL element OEL via the thin film transistor Tr62. The state in which the light emission drive current flows is maintained, and the light emission operation is continued. This light emission operation is controlled so as to be continued, for example, for one frame period until the gradation signal voltage Vpix corresponding to the next display data is written to each display pixel.
Such a drive control method adjusts the voltage applied to each display pixel (the gradation signal voltage Vpix applied to the gate terminal of the thin film transistor Tr62), thereby adjusting the current value of the light emission drive current that flows through the organic EL element OEL. Since it is controlled to emit light at a predetermined luminance gradation, it is called a voltage designation method or a voltage application method.

  On the other hand, as shown in FIG. 22B, the display pixel described in Patent Document 2 and the like includes first and second scanning lines SL1 and SL2 and a data line DL arranged in parallel to each other. Near each intersection, a thin film transistor Tr71 having a gate terminal connected to the first scan line SL1, a source terminal and a drain terminal connected to the data line DL and the contact N71, and a gate terminal connected to the second scan line SL2, respectively. And a thin film transistor Tr72 having a drain terminal connected to the contact N71 and the contact N72, a gate terminal connected to the contact N72, a drain terminal connected to the contact N71, and a high power supply voltage Vdd applied to the source terminal, A thin film transistor Tr74 having a gate terminal connected to the contact N72 and a high power supply voltage Vdd applied to the source terminal And the organic EL element OEL in which the anode terminal is connected to the drain terminal of the thin film transistor Tr74 of the lower pixel driving circuit DP2 and the ground potential is applied to the cathode terminal. .

In FIG. 22B, the thin film transistor Tr71 is composed of an n-channel field effect transistor, and the thin film transistors Tr72 to Tr74 are composed of p-channel field effect transistors. CP2 is a parasitic capacitance formed between the gate and source of the thin film transistors Tr73 and Tr74.
In the light emission driving circuit DP2 having such a configuration, the four transistors (switching means) composed of the thin film transistors Tr71 to Tr74 are controlled to be turned on and off at a predetermined timing, so that an organic EL can be obtained as shown below. The element OEL is controlled to emit light.

  That is, in the light emission drive circuit DP2, a high-level scanning signal Vsel1 is applied to the scanning line SL1 and a low-level scanning signal Vsel2 is applied to the scanning line SL2 by a gate driver (not shown) to set the display pixel in a selected state. Then, the thin film transistors Tr71 and Tr72 are turned on, and the gradation current Ipix corresponding to the display data supplied to the data line DL by the data driver (not shown) is taken into the contact N72 via the thin film transistors Tr71 and Tr72. The current level of the gradation current Ipix is converted to a voltage level by the thin film transistor Tr73, and a predetermined voltage is generated between the gate and the source (writing operation).

  Next, for example, when a high level scanning signal Vsel2 is applied to the scanning line SL2, the thin film transistor Tr72 is turned off, whereby the voltage generated between the gate and the source of the thin film transistor Tr73 is held by the parasitic capacitance CP2, and then the scanning is performed. When the low level scanning signal Vsel1 is applied to the line SL1, the thin film transistor Tr71 is turned off, thereby electrically disconnecting the data line DL and the pixel driving circuit DP2. Thereby, the thin film transistor Tr74 is turned on by the potential difference based on the voltage held in the parasitic capacitance CP2, and a predetermined light emission drive current flows from the high power supply voltage Vdd to the ground potential via the thin film transistor Tr74 and the organic EL element OEL. The organic EL element OEL emits light with a luminance gradation corresponding to display data (light emission operation).

Here, the light emission drive current supplied to the organic EL element OEL via the thin film transistor Tr74 is controlled to have a current value based on the luminance gradation of the display data, and this light emission operation depends on the next display data. Until the gradation current Ipix is written to each display pixel, for example, control is performed so as to continue for one frame period.
In such a drive control method, each display pixel (the gate terminal of the thin film transistor Tr73; the contact N72) supplies a gradation current Ipix designating a current value according to display data, and a voltage held according to the current value. On the basis of the above, the light emission drive current that flows through the organic EL element OEL is controlled to perform the light emission operation at a predetermined luminance gradation, and therefore, this is called a current designation method or a current application method.

JP 2002-156923 A (page 4, FIG. 2) JP 2001-147659 A (pages 7 to 8, FIG. 1)

However, the display device provided with the light emission drive circuit as shown in the prior art in the display pixel has the following problems.
That is, in the display pixel including the light emission drive circuit DP1 adopting the voltage specifying method as shown in FIG. 22A, the organic EL element OEL is set according to the gradation signal voltage Vpix applied to each display pixel. Therefore, the element characteristics (channel resistance, etc.) of the thin film transistors Tr61 and Tr62 constituting the light emission drive circuit DP1 and the element characteristics (resistance, etc.) of the organic EL element OEL are controlled. ), However, when there are variations or fluctuations (deterioration) depending on the external environment such as the ambient temperature and the usage time, the adverse effect of changing the current value of the light emission drive current supplied to the organic EL element OEL. Therefore, it has been difficult to stably realize desired light emission characteristics (light emission operation at a predetermined luminance gradation) over a long period of time.
In addition, if each display pixel constituting the display panel is miniaturized in order to improve the display image quality, the variation in element characteristics of the thin film transistors Tr61 and Tr62 constituting the light emission drive circuit DP1 increases. As a result, there is a problem that the gradation control cannot be performed, and the display characteristics of each display pixel vary, resulting in deterioration of image quality.

On the other hand, in the display pixel having the light emission drive circuit DP2 adopting the current designating method as shown in FIG. 22B, the current level of the gradation current Ipix corresponding to the display data supplied to each display pixel is set. A thin film transistor Tr73 (current / voltage conversion transistor) that converts to a voltage level and a thin film transistor Tr74 (light emission drive transistor) that supplies a drive current of a predetermined current value to the organic EL element OEL are provided and supplied to the organic EL element OEL. Therefore, the thin film transistors Tr73 and Tr74 are compared with the light emission drive circuit DP1 (FIG. 22A) employing the voltage designation method. This has the advantage that the influence of variations in the operating characteristics can be suppressed to some extent.
However, in each thin film transistor and organic EL element OEL constituting the light emission drive circuit DP2 as described above, the deterioration of element characteristics due to changes in the external environment, changes with time, etc. can be completely (more appropriately and satisfactorily) suppressed. However, it still has a problem that it is difficult to realize stable light emission characteristics over a long period of time, and further, good display image quality.

  Therefore, in view of the various problems described above, the present invention emits light with an appropriate luminance gradation according to display data regardless of deterioration or variation in the light emission characteristics of each display pixel due to changes in the external environment or changes over time. It is an object of the present invention to provide a display device that can be operated and can display image information satisfactorily over a long period of time and a drive control method thereof.

  The invention according to claim 1 selects the display pixels for each row of a display panel in which a plurality of display pixels are two-dimensionally arranged on a transparent insulating substrate, and applies a gradation signal according to display data. Thus, in the display device that causes the display pixels to emit light at a luminance gradation corresponding to the display data and displays desired image information on the display surface side of the display panel, the display device includes: A light guide plate disposed on the back side, and a correction circuit unit that corrects the gradation signal applied to each of the display pixels according to the light emission characteristics of the display pixel, and the correction circuit unit includes: A specific amount detection means for detecting a specific amount according to the light emission characteristics of the display pixel when a light receiving surface is provided opposite to at least one side end surface of the light guide plate and a specific gradation signal is applied; At least the detected feature An initial value based on an initial value of the specific amount corresponding to the specific gradation signal in the display pixel, and a storage means for holding detected gradation data based on the amount; the detected gradation data stored in the storage means; Based on the comparison result with the gradation data, a correction signal for correcting the gradation signal applied to the display pixel so that the relationship between the display data and the specific amount is close to the relationship in the initial state of the display pixel. And a signal correction means for generating.

  According to a second aspect of the present invention, in the display device according to the first aspect, the display panel extends in the column direction and a plurality of scanning lines arranged in the row direction on the insulating substrate. The display pixels are arranged at intersections of the plurality of scanning lines and the plurality of data lines, and the display device is arranged for each row of the display panel at a predetermined timing. A scanning drive circuit that sequentially applies a scanning signal to the display pixels of the display pixel to set the selected state, and generates a gradation signal according to the display data, and applies the gradation signal to the display pixels in the row set to the selected state And a signal driving circuit.

  According to a third aspect of the present invention, in the display device according to the first or second aspect, the specific amount detection unit applies the specific gradation signal to at least the display pixel. A light receiving element that measures the luminance corresponding to the light emission luminance of the light guide plate, and the light receiving element includes the light guide plate out of light emitted from the display pixel when the specific gradation signal is applied to the display pixel. A part of the light extracted to the side is detected.

According to a fourth aspect of the present invention, in the display device according to any one of the first to third aspects, at least one of the specific amount detecting means is provided in close contact with only one side end surface of the light guide plate. It is characterized by being.
According to a fifth aspect of the present invention, in the display device according to any one of the first to third aspects, at least one of the specific amount detection means is in close contact with each of a plurality of different side end surfaces of the light guide plate. It is provided.

According to a sixth aspect of the present invention, in the display device according to any one of the first to fifth aspects, the display device is configured to transmit light emitted from the display pixels between the display pixels and the light guide plate. Among these, it is characterized by comprising a light collecting means for condensing the light extracted to the light guide plate side and guiding it to the light guide plate.
A seventh aspect of the present invention is the display device according to any one of the first to sixth aspects, wherein the light guide plate emits light extracted from the display pixels to the light guide plate side. A light guide means for guiding light in the installation direction of the specific amount detection means is provided.

According to an eighth aspect of the present invention, in the display device according to any one of the first to seventh aspects, the storage unit holds the initial gradation data in addition to the detected gradation data.
According to a ninth aspect of the present invention, in the display device according to any one of the first to eighth aspects, the specific amount is detected by the specific amount detecting means when the display panel is powered on and the display panel. It is executed at least at any timing after elapse of a predetermined time or more after the power is turned on.

  According to a tenth aspect of the present invention, in the display device according to any one of the third to ninth aspects, the display data includes digital data, and the correction circuit unit has the specific amount output from the light receiving element. Signal conversion means for converting the signal level into digital data and generating at least the detected gradation data is provided.

According to an eleventh aspect of the present invention, in the display device according to any one of the third to tenth aspects, the light receiving element is a photodiode.
According to a twelfth aspect of the present invention, in the display device according to any one of the third to tenth aspects, the light receiving element is a photoconductive sensor.
According to a thirteenth aspect of the present invention, in the display device according to any one of the third to tenth aspects, the light receiving element is a photosensor having a double-gate transistor structure.

  According to a fourteenth aspect of the present invention, in the display device according to any one of the first to thirteenth aspects, the display pixel is applied from the signal driving circuit at least by the scanning signal applied from the scanning driving circuit. A light emitting drive switch that picks up the gradation signal, a light emission drive switch that passes a drive current having a current value corresponding to the gradation signal, and a storage capacitor that stores a voltage component corresponding to the gradation signal. A drive circuit and a current control type light emitting element that emits light with a luminance gradation corresponding to the current value of the drive current.

  According to a fifteenth aspect of the present invention, in the display device according to the fourteenth aspect, the light emitting element is an organic electroluminescent element, and the organic electroluminescent element is configured to perform the predetermined light emitting operation. To extract a part of light emitted by the organic electroluminescent element to the light guide plate side at an arbitrary position of the electrode on the light guide plate side among the pair of electrodes for supplying a drive current An opening is provided.

  According to a sixteenth aspect of the present invention, the display pixels for each row of the display panel in which a plurality of display pixels are two-dimensionally arranged on a transparent insulating substrate are selected and a gradation signal corresponding to display data is applied. Thus, in the display device drive control method for causing the display pixels to emit light at a luminance gradation corresponding to the display data and displaying desired image information on the display surface side of the display panel, A step of applying a specific gradation signal, and a light receiving element provided with a light receiving surface opposite to at least one side end surface of a light guide plate disposed on the back side of the display panel. A step of detecting a specific amount according to the light emission characteristic, a step of holding detection gradation data based on the detected specific amount, the held detection gradation data, and the specific pixel in the display pixel Based on the comparison result with the initial gradation data based on the initial value of the specific amount corresponding to the tone signal, the relationship between the display data and the specific amount is close to the relationship in the initial state of the display pixel. Correcting the gradation signal applied to the display pixel.

According to a seventeenth aspect of the present invention, in the display device drive control method according to the sixteenth aspect, the step of detecting the specific amount is radiated in a state where a specific gradation signal is applied to the display pixel. Of the light, after being extracted to the light guide plate side, it propagates through the light guide plate, and a part of the light emitted from the side end surface is detected by the light receiving element.
According to an eighteenth aspect of the present invention, in the display device drive control method according to the sixteenth or seventeenth aspect, the step of detecting the specific amount is performed when the display panel is turned on and when the display panel is turned on. It is characterized in that it is performed at least at any timing after a predetermined time has elapsed.

According to a nineteenth aspect of the present invention, in the display device drive control method according to any one of the sixteenth to eighteenth aspects, the specific gradation signal is used for causing the display pixel to perform a light emission operation at a maximum luminance gradation. The signal level is set.
According to a twentieth aspect of the present invention, in the display device drive control method according to any one of the sixteenth to eighteenth aspects, the specific gradation signal causes the display pixel to emit light at a plurality of different luminance gradations. It is characterized by being set to the signal level.

  In accordance with a twenty-first aspect of the present invention, in the drive control method for a display device according to any of the sixteenth to twentieth aspects, the display pixel passes a drive current having a current value corresponding to the gradation signal, and A step of detecting the specific amount, comprising: a light emission driving circuit that accumulates a voltage component according to a gradation signal; and a current control type light emitting element that emits light at a luminance gradation according to a current value of the driving current. Measuring the luminance corresponding to the light emission luminance of the light emitting element when the specific gradation signal is applied to the light emission driving circuit provided in each of the display pixels. It is characterized by.

  That is, the display device and the drive control method thereof according to the present invention configure the display pixel by applying a gradation signal (gradation signal voltage or gradation signal current) corresponding to the display data to each display pixel. In a display device that displays desired image information on a display panel by causing a light emitting element such as an organic EL element to emit light at a predetermined luminance gradation, a gradation applied to the display pixel according to the light emission characteristics of the display pixel By providing a correction circuit unit that corrects the signal level (voltage value or current value) of the signal, each time the power is turned on to the display panel or after a predetermined time has elapsed after the power is turned on to the display panel, When a specific gradation signal based on luminance detection data (for example, a signal level for light emission operation at the highest luminance gradation; highest gradation voltage or highest gradation current) is applied to the display pixel Departure The luminance (a specific amount corresponding to the light emission characteristics) is measured by a light receiving element provided so that the light receiving surface faces the side end surface of the light guide plate disposed on the back side of the display panel, and the level based on the detected data is measured. Based on the comparison between the tone data (detected tone data) and the tone data (initial tone data) in the initial state of the display pixel, the tone signal applied to each display pixel during the display operation of the image information An operation of correcting the signal level (voltage value or current value) so as to approach the initial state of the display pixel is performed.

  Here, at least one of the correction circuit units according to the present invention is provided in close contact with at least one side end surface of the light guide plate arranged on the back side of the display panel so that the light receiving surface is opposed. A light receiving sensor unit (a specific amount) that detects a part of the back light that is extracted from the opening formed on the back side of the display panel and propagates in the light guide plate out of the light emitted from the display pixel. Detection unit), a storage unit (storage unit) that holds detected gradation data based on the light emission luminance of the display pixel when a specific gradation signal is applied, detected by the light receiving sensor unit, and held in the storage unit Correcting the display data based on a correction value obtained by comparing the detected gradation data of each display pixel and the initial gradation data based on the initial value of the emission luminance when a specific gradation signal is applied, Data after correction (correction signal It has compared correcting unit for generating a (signal correction means), a a.

  As a result, the specific amount detection operation is executed at a predetermined timing prior to the normal image display operation, and the detected gradation data based on the emission luminance of the display pixel when the specific gradation signal is applied is retained. In the image display operation, the detected gradation data is compared with the initial gradation data based on the light emission luminance when a specific gradation signal in the initial state (initial characteristic) of the display pixel is applied. A correction value (digital value) is generated for each display pixel according to the result, and a data correction operation is performed to correct the display data for each display pixel based on the correction value. By supplying to the driver (signal driving circuit), the gradation signal (gradation signal voltage or gradation signal current) applied to each display pixel is corrected.

  In particular, in the present invention, the light receiving element constituting the light receiving sensor unit is provided so as to be in close contact with an arbitrary position on the side end surface of the light guide plate, and the light receiving surface of the light receiving element is provided on the side end surface of the light guide plate. By providing them so as to face each other, one or a plurality of light receiving elements are extracted from the light emitted from each display pixel (light emitting element) to the back side of the display panel, propagate in the light guide plate, and beside. The back light emitted from the end face can be favorably detected as a specific amount according to the light emission characteristics of the display pixel.

  In addition, an opening for taking out part of light emitted from each display pixel (light emitting element) as back light on the back side of the display panel, and further, between the light emitting element and the light guide plate constituting each display pixel. Condensing means such as a condensing lens and a light guide that collects the extracted back light and guides it to the light guide plate, or a light receiving sensor unit provided on the side end surface of the back light incident on the surface of the light guide plate By providing light guide means such as a wedge-shaped groove (prism array) that guides light in the direction, even if the back light extracted from each display pixel is very small, a specific amount corresponding to the light emission characteristics of the display pixel can be obtained. It can be detected well.

  Therefore, based on a specific amount detected by the light receiving sensor unit according to the light emission characteristics of the display pixel, the display pixel (light emitting element) with respect to the display data always displays the light emission luminance so as to approximate the initial light emission luminance. Since the data (that is, the gradation signal) can be corrected, even if the element characteristics of the light emitting element and the functional element (thin film transistor) constituting each display pixel change with time, the display data For each display pixel, an appropriately corrected gradation signal is applied to each display pixel so that each display pixel (light-emitting element) can emit light with a light emission luminance that approximates the initial state, and image information is good and stable over a long period of time. Can be displayed with image quality.

  In addition, for example, a photodiode, a photoconductive sensor, a double gate type photo sensor, or the like can be applied as a light receiving element provided in the light receiving sensor unit. By applying the light receiving element used, the structure of the light receiving sensor portion can be simplified and thinned, so that the manufacturing process can be simplified and the yield can be reduced while reducing the device scale of the correction circuit portion and the display device. And a variation in sensor characteristics can be reduced, and a display device having a small size, low cost, and good display quality can be realized.

  Further, the correction circuit unit includes conversion means for generating the gradation data by converting a specific amount of signal level obtained from each display pixel into digital data, so that it is held in advance as digital data in the data correction operation. A method for comparing the initial gradation data based on the light emission luminance corresponding to the specific gradation signal in the initial state of the light emitting element and the detected gradation data composed of digital data acquired by the specific amount detection operation. Can be applied.

  Here, as described above, a specific display pixel (light emitting element) is applied by applying a configuration in which a plurality of light receiving sensor portions (light receiving elements) are provided on the side end surface of the light guide plate disposed on the back side of the display panel. Of the light radiated from the light, it can capture more back light (through the number of light receiving elements) extracted through the opening and convert it into detection gradation data consisting of digital data. The reliability of detected gradation data can be improved by suppressing the influence of noise other than light radiated from a specific display pixel, and more accurate display data correction processing can be realized. .

Hereinafter, a display device and a drive control method thereof according to the present invention will be described in detail with reference to embodiments.
<Display device>
First, a configuration of a display device according to the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating an embodiment of the overall configuration of a display device according to the present invention, and FIG. 2 is a schematic configuration diagram illustrating an exemplary configuration of a main part of the display device according to the present embodiment. Here, in the following description, a circuit configuration including a voltage-designated pixel driving circuit (light-emitting driving circuit) shown in the related art and an organic EL element as a light-emitting element is used as a display pixel constituting the display panel. However, the display device according to the present invention is not limited to this, and the current value of the light emission drive current (drive current) is set based on the gradation signal voltage at least in each display pixel, and the display device according to the current value. Any device including other light-emitting elements such as a light-emitting diode can be suitably applied as long as the current-controlled light-emitting element is driven and controlled with luminance gradation. In FIGS. 1 and 2, for convenience of illustration, the light guide plate is shown to be displaced from the display panel. However, as shown in FIGS. 4A and 4B described later, A light guide plate is disposed so as to face (align) the entire area of the display panel. Further, the same components as those in the conventional technology are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  As shown in FIG. 1 and FIG. 2, the display device 100A according to the present embodiment is roughly composed of a plurality of scanning lines SL1, SL2,. (Hereinafter collectively referred to as “scan line SL”) and a plurality of data lines DL1, DL2,... (For convenience, hereinafter referred to as “data line DL”). A display panel 110A in which a plurality of display pixels EMA each including at least a pixel driving circuit (corresponding to the above-described light emission driving circuit) DCA and an organic EL element (current control type light emitting element) OEL are arranged in the vicinity of each intersection , Connected to each scanning line SL of the display panel 110A, and sequentially scanning the high-level scanning signals Vscan1, Vscan2,... (Hereinafter also collectively referred to as “scanning signal Vscan”) at a predetermined timing. Is applied to the gate driver (scanning drive circuit) 120A for setting (scanning) the display pixel EMA group for each row to the selected state, and to each data line DL of the display panel 110A, and display data (specifically, Is a grayscale signal voltage Vdata1, Vdata2,... (Hereinafter also collectively referred to as “grayscale signal voltage Vdata”; grayscale signal) based on corrected data (to be described later). A data driver (signal drive circuit) 130A supplied to the display panel, a light guide plate 140 disposed on the opposite side (rear side) of the display panel 110A, and a side end surface of the light guide plate 140 A specific amount (light emission luminance) corresponding to the light emission characteristic (or element characteristic) of the organic EL element OEL provided in each display pixel EMA of the display panel 110A is detected at a predetermined timing. Based on the light receiving sensor unit (specific amount detecting means) 150 and the specific amount detected by the light receiving sensor unit 150, the light emission characteristics in each display pixel EMA (organic EL element OEL) are maintained in a constant state. A correction control circuit 160 that corrects display data supplied to the data driver 130A, and at least a scanning control signal, a data control signal, and a correction control for controlling the operation state of the gate driver 120A, the data driver 130A, and the correction control circuit 160 Based on a system controller 170 that generates and outputs a signal, and a video signal supplied from the outside of the display device 100A, display data (display signal) including a digital signal is generated, and the correction control circuit 160 is used to generate display data. The display data is supplied to the data driver 130A and the display data is displayed on the display panel 110. Timing signal for displaying an image (system clock or the like) extract, or is configured to include a display signal generating circuit 180 supplies the generated by the system controller 170, to. Here, the light receiving sensor unit 150 and the correction control circuit 160 according to the present embodiment constitute a correction circuit unit according to the present invention.

Hereafter, each said structure is demonstrated.
(Display panel 110A)
A display panel 110A applicable to the display device 100A according to the present embodiment includes, for example, each data line DL in addition to the scanning lines SL and the data lines DL arranged so as to be orthogonal to each other, as shown in FIG. Are arranged in parallel with each other, and each intersection of the scanning line SL, the data line DL, and the power supply line VL is provided with the power supply lines VL1, VL2,. In addition, a display pixel EMA having a pixel drive circuit DCA and an organic EL element OEL having a circuit configuration equivalent to that of the light emission drive circuit DP1 (see FIG. 22A) corresponding to the voltage specifying method shown in the above-described prior art is provided. It has a connected configuration. Here, the power supply line VL is connected to a constant power supply voltage (high potential power supply) Vdd having a positive voltage at one end side.

  That is, as shown in FIG. 2, each display pixel EMA includes an n-channel thin film transistor (selection transistor; selection transistor) having a gate terminal connected to the scanning line SL and a source terminal and a drain terminal connected to the data line DL and the contact N11. A pixel drive circuit DCA having a switch Tr11, and a p-channel thin film transistor (light emission drive transistor; light emission drive switch) Tr12 having a gate terminal connected to the contact N11 and a source terminal connected to the power supply line VL, and an anode The organic EL element OEL has a terminal connected to the drain terminal of the thin film transistor Tr12 of the pixel drive circuit DCA and a cathode terminal connected to the ground potential (Vgnd). In the pixel driving circuit DCA shown in FIG. 2, Ca is a parasitic capacitance (holding capacitance) formed between the gate and the source of the thin film transistor Tr12 or an auxiliary capacitance additionally formed between the gate and the source. is there.

  In the display pixel EMA having such a configuration, the scanning signal Vscan applied to the scanning line SL from the gate driver 120A at a predetermined timing and the gradation signal voltage Vdata applied to the data line DL from the data driver 130A. Based on this, the light emission drive current flowing through the organic EL element OEL is controlled by the pixel drive circuit DCA, and the light emission operation and the luminance gradation during light emission are controlled. A specific circuit layout and cross-sectional configuration of the display pixel EMA formed on the display panel 110A will be described in detail later.

  In the present embodiment, as the pixel driving circuit DCA constituting the display pixel EMA, the n-channel type thin film transistor (selection transistor) Tr11 and the p-channel type thin film transistor (light emission driving) are provided as in the configuration shown in the prior art. The case where the circuit configuration including the transistor Tr12 is applied has been described. According to such a circuit configuration, a p-channel type and an n-channel type thin film transistor are mixed, so that a thin film transistor having good operating characteristics can be manufactured by applying a polysilicon manufacturing process. Thus, it is possible to realize a pixel driving circuit in which variation in light emission characteristics of display pixels is suppressed.

  Further, the pixel driving circuit applicable to the present invention is not limited to the circuit configuration in which the p-channel type and the n-channel type thin film transistor are mixed as described above, but has a circuit configuration including a single-channel type thin film transistor. It can also be applied. That is, in the present embodiment, only an example applicable as a pixel driving circuit is shown, and at least a selection transistor that sets a display pixel (pixel driving circuit) to a selected state based on a scanning signal, and the selection If the pixel drive circuit includes a light emission drive transistor that generates a predetermined light emission drive current based on display data and supplies the light emission element based on the grayscale signal voltage applied in the state, other circuit configurations It may have.

(Gate driver 120A)
Based on the scanning control signal supplied from the system controller 170, the gate driver 120A sequentially applies the high level scanning signal Vscan to each scanning line SL, thereby setting the display pixel EMA group for each row to the selected state. Then, control is performed so that a predetermined grayscale signal voltage Vdata applied by the data driver 130A via the data line DL is written to the pixel driving circuit DCA.

  Here, specifically, the gate driver 120A, for example, as shown in FIG. 2, includes a plurality of stages of shift blocks SB each composed of a shift register and a buffer corresponding to each scanning line SL. The shift signal is sequentially shifted from the upper side to the lower side of the display panel 110A by the shift register based on the scanning control signals (scanning start signal SST, scanning clock signal SCK, etc.) supplied from the buffer, and the generated shift signal is buffered. Then, it is converted to a predetermined voltage level (high level) and is output to each scanning line SL as a scanning signal Vscan (Vscan1 to VscanN).

(Data driver 130A)
FIG. 3 is a block diagram illustrating a configuration example of a main part of a data driver applied to the display device according to the present embodiment.
Based on the data control signal supplied from the system controller 170, the data driver 130A outputs display data (after-correction data) that is output from the display signal generation circuit 180 and is supplied via a correction control circuit 160 described later. ) At a predetermined timing, an analog signal voltage corresponding to the display data is generated, and applied to each data line DL as a gradation signal voltage Vdata.

Here, specifically, the data driver 130A sequentially shifts the shift signal based on the data control signals (shift clock signal CLK, sampling start signal STR) supplied from the system controller 170, for example, as shown in FIG. , And data for sequentially fetching display data (corrected data) for one row supplied from the display signal generation circuit 180 via the correction control circuit 160 based on the input timing of the shift signal. Based on the register circuit 132, the data latch circuit 133 that collectively holds display data for one row fetched by the data register circuit 132 based on the data control signal (data latch signal STB), and the gradation reference voltages V0 to Vp. Based on this, the stored display data is changed to a predetermined analog signal voltage. Output circuit that applies the analog signal voltage as the gradation signal voltage Vdata (Vdata1 to VdataM) to each data line DL at a timing based on the D / A converter 134 and the data control signal (output enable signal OE). 135.
By such a data driver 130A, a gradation signal voltage (analog signal) Vdata corresponding to corrected data of display data composed of a digital signal supplied from the display signal generation circuit 180 via the correction control circuit 160 is generated. Thus, the data lines DL are output collectively or sequentially at a predetermined timing.

(Light guide plate 140, light receiving sensor unit 150)
FIG. 4 is a schematic configuration diagram showing a relationship between a display panel (display pixel) applied to the display device according to the present embodiment, a light guide plate, and a light receiving sensor unit. Here, in FIG. 4B, in order to clarify the optical path of the back light propagating through the light guide plate, a part of the hatching is omitted.
Specifically, each display pixel EMA arranged two-dimensionally on the display panel 110A is arranged on one surface side (lower side of the drawing) of a transparent insulating substrate 111 such as a glass substrate, as shown in FIG. In general, an anode electrode 112 made of a transparent electrode material such as ITO (Indium Thin Oxide), an organic EL layer 113 made of a light emitting material such as an organic compound, and a cathode electrode 114 made of a metal material and having a reflective property are sequentially laminated. A configuration in which a plurality of display pixels each including an organic EL element OEL and a pixel driving circuit (not shown) formed in a thin film for each organic EL element OEL are two-dimensionally arranged (for example, arranged in a matrix) have. In FIG. 4B, only one of the plurality of organic EL elements OEL formed on the insulating substrate 111 is shown for convenience of illustration.

  Here, for example, as shown in FIG. 4B, the organic EL layer 113 includes a hole transport layer (hole injection layer) 113a made of a polymer hole transport material and a polymer electron transporting light emission. An electron transporting light emitting layer (light emitting layer) 113b made of a material is laminated. Although not shown, such an organic EL element OEL (display pixel) is sealed and sealed with, for example, an epoxy-based sealing layer or a sealing substrate (sealing glass or sealing film), It has a configuration that is cut off from the outside air.

  In the display pixel EMA applied to this embodiment, at least the organic EL layer 113 is exposed at an arbitrary position of the cathode electrode 114 constituting the organic EL element OEL, as shown in FIG. 4B. An opening HLa is provided, and in the light emission operation described later, a part of the light hν emitted from the organic EL layer 113 (mostly emitted toward the front surface of the display panel 110) (back light LTb) Via HLa, the light is emitted to the back side (downward in the drawing) opposite to the visual field side. A specific configuration example of the display pixel EMA (particularly, the organic EL element OEL) will be described in detail later.

  The light guide plate 140 is made of a light-transmitting insulating flat plate such as glass or acrylic, and is on the back side of the display panel 110A as shown in FIGS. It has a configuration in which the OEL is sealed or in close contact with a sealing layer or a sealing substrate (not shown). Here, the display panel 110 </ b> A and the light guide plate 140 are configured such that the back light LTb emitted from at least the organic EL element OEL and emitted through the opening HLa provided in the cathode electrode 114 is the incident surface of the light guide plate 140. In order to reach the inside of the light guide plate 140 in a state in which reflection and scattering are suppressed as much as possible, a member having a refractive index continuous (optically continuous) is interposed between the display panel 110A and the light guide plate 140. The configuration can be applied.

In addition, the light receiving sensor unit 150 has a configuration installed so as to be in close contact with the side surface (side end surface) 140s of the light guide plate 140 described above, for example, as shown in FIGS. 4 (a) and 4 (b). Yes.
Here, the light receiving sensor unit 150 applied to the present embodiment particularly has a specific amount corresponding to the light emission characteristics of each display pixel EMA, that is, the light emitted from the organic EL element OEL provided in each display pixel EMA. A sensor substrate having a light receiving element such as a photodiode for measuring the light emission luminance of each organic EL element OEL by receiving a part of the light is formed on a silicon substrate or a glass substrate and cut. For example, an adhesive 141 is applied so that the light receiving surface of the light receiving element faces the side end surface 140s of a transparent insulating flat plate such as a glass substrate constituting the light guide plate 140 as shown in FIG. It has the structure provided by adhering through and closely contacting. The connection wiring 151 is a wiring for connecting the correction control circuit 160 and the light receiving sensor unit 150, and for example, a flexible wiring is applied. A specific circuit configuration of the light receiving sensor unit 150 will be described later in detail.

  In the display panel 110A (organic EL element OEL) having such a configuration, by applying a positive voltage from the DC voltage source 115 to the anode electrode 112 and a negative voltage to the cathode electrode 114, as shown in FIG. The light hν is emitted based on the energy when the holes injected into the hole transport layer 113a and the electrons injected into the electron transport light emitting layer 113b are recombined in the organic EL layer 113. The light hν is transmitted through the transparent anode electrode 112 or reflected by the cathode electrode 114, and is emitted to the other surface side (viewing side; upper side in the drawing) of the insulating substrate 111. A part of the light hν is emitted as back light LTb into the light guide plate 140 provided on the back side of the display panel 110A through the opening HLa provided in the cathode electrode 114. At this time, the emission intensity of the light hν is controlled according to the amount of current flowing between the anode electrode 112 and the cathode electrode 114.

(Correction control circuit 160)
For example, as shown in FIG. 2, the correction control circuit 160 has a specific amount corresponding to the light emission characteristic in each display pixel EMA (organic EL element OEL), specifically, a grayscale signal corresponding to a specific grayscale level. An amplifier (amplifier) AMP to which detection data (analog signal level) output from the light receiving sensor unit 150 that measures the light emission luminance of the organic EL element OEL in a state where a voltage is applied is input, and a predetermined signal level by the amplifier AMP Analog-to-digital converter (hereinafter abbreviated as “A / D converter”; signal conversion means) ADC that converts the detected data amplified to analog to digital gradation data by analog-to-digital conversion processing, and each display A storage unit (recording unit) including a buffer memory or the like that sequentially captures the digital gradation data (detection gradation data) for each pixel and temporarily stores it. Means) Each display stored in the storage unit BM with respect to display data (digital signal) provided between the BM and the display signal generation circuit 180 and the data driver 130A and supplied from the display signal generation circuit 180. A correction value is generated by comparing digital gradation data for each pixel EMA (organic EL element OEL) with digital gradation data (initial gradation data) based on light emission luminance in the initial state of each display pixel EMA stored in advance. Then, based on the correction value, correction processing is performed in a direction in which the light emission luminance in the display data of the specific gradation level is always equal to the light emission luminance in the initial state, and the correction value is sent to the data driver 130A after correction data ( And a comparison correction unit (signal correction means) CMR supplied as a correction signal).

  Here, the correction control circuit 160 configured as described above captures the operation state (at least detection data based on the emission luminance detected in each display pixel) based on a correction control signal output from the system controller 170 described later. Whether or not to perform the specific amount detection operation to be held is controlled. The digital gradation data based on the light emission luminance in the initial state of each display pixel may be stored in the storage unit BM at the time of shipment of the display device from the factory, for example, and is not limited thereto. Instead, it may be stored in a storage unit different from the storage unit BM.

(System controller 170)
The system controller 170 scans at least the gate driver 120A, the data driver 130A, and the correction control circuit 160 with a scanning control signal (such as the above-described scanning start signal SST and scanning clock signal SCK) and data control. By outputting signals (the above-described output enable signal OE, data latch signal STB, sampling start signal STR, shift clock signal CLK, etc.) and correction control signals, each driver and control circuit are operated at a predetermined timing to display The display data output from the signal generation circuit 180 is corrected based on the correction value generated by the correction control circuit 160, and the scanning signal Vscan and the gradation signal voltage Vdata are generated, and each scanning line SL and data are generated. Each display by applying to line DL The light emitting operation in the element EMA are continuously executed, performs control to display on the display panel 110A of image information based on a predetermined video signal.

(Display signal generation circuit 180)
For example, the display signal generation circuit 180 extracts a luminance gradation signal component from a video signal supplied from the outside of the display device 100A, and converts the luminance gradation signal component into a digital signal for each row of the display panel 110A. Is supplied to the data register circuit 132 of the data driver 130A through the correction control circuit 160. Here, when the video signal includes a timing signal component that defines the display timing of image information, such as a television broadcast signal (composite video signal), the display signal generation circuit 180 is configured as shown in FIG. In addition to the function of extracting the luminance gradation signal component, a function of extracting the timing signal component and supplying it to the system controller 170 may be provided. In this case, the system controller 170 scans signals and data supplied individually to the gate driver 120A, the data driver 130A, and the correction control circuit 160 based on the timing signal supplied from the display signal generation circuit 180. A control signal and a correction control signal are generated.

  When the video signal supplied from the outside of the display device 100A is formed by a digital signal and the timing signal is supplied separately from the video signal, the video signal (digital signal) is used as display data as it is. The display signal generation circuit 180 may be omitted by supplying the data driver 130A via the correction control circuit 160 and supplying the timing signal directly to the system controller 170. In the display device drive control method to be described later, as shown in FIG. 1, display data is generated by the display signal generation circuit 180 based on the video signal, and is supplied to the data driver 130A via the correction control circuit 160. A description will be given of the case.

Next, the display pixel portion applied to the display device according to the present embodiment described above will be described in more detail with reference to the drawings.
FIG. 5 is a configuration diagram showing a specific example (circuit layout and cross-sectional structure) of a display pixel portion applied to the display device according to the present embodiment.
In the layout design process using CAD or the like, the display pixel EMA having an equivalent circuit as shown in FIG. 2 is specifically arranged in the row direction, for example, as shown in FIG. A pixel formation region is formed in a rectangular region surrounded by the scanning line SL, the data line DL disposed orthogonal to the scanning line SL, and the power supply line VL disposed in parallel to the data line DL. It is prescribed. The thin film transistors Tr11 and Tr12, the capacitor Ca, and the inter-element wiring portion for connecting the thin film transistors Tr11 and Tr12 are arranged along substantially the outer edge (scanning line SL, data line DL, and power supply line VL) of the pixel formation region. (Refer to the pixel drive circuit DCA shown in FIG. 2).

  Further, the organic EL element OEL is formed on the insulating substrate 111 in the area (organic EL element formation area) ARel excluding the formation areas such as the thin film transistors Tr11 and Tr12 and the inter-element wiring portion in the pixel formation area shown in FIG. As shown in b), a transparent anode electrode 112 such as ITO connected to the drain electrode of the thin film transistor Tr12 through the insulating film (gate insulating film of the thin film transistor Tr12), the hole transport layer 113a, and the electron transport light emission The layer 113b and an opaque cathode electrode 114 such as a metal layer are sequentially stacked.

  Here, a partition 116 made of an insulating material that separates both regions is provided at a boundary portion between the adjacent display pixels EMA and the organic EL element formation region ARel, and insulation of the region where the partition 116 is formed is provided. On the conductive substrate 111, thin film transistors Tr11 and Tr12, an inter-element wiring portion, and the like constituting the pixel driving circuit DCA are formed. In addition, an opening HLa is provided at an arbitrary position of the cathode electrode 114 in each layer constituting the organic EL element OEL. Further, the entire region on the insulating substrate 111 including the organic EL element OEL in which the opening HLa is formed and the partition wall 116 is sealed by the sealing layer 117 and the sealing substrate 118, and separated from the sealing substrate 118. Then, a light guide plate (not shown) 140 is arranged or bonded so as to be in close contact with the sealing substrate 118.

  In FIG. 5A, only the scanning line SL, the data line DL, the power supply line VL, the thin film transistors Tr11, Tr12, and the anode electrode 112 formed on the insulating substrate 111 are laid out in order to simplify the illustration. In FIG. 5B, only the organic EL element OEL (each layer of the organic EL element formation region ARel), the thin film transistor Tr12, the partition wall 116, the sealing layer 117, and the sealing substrate 118 are shown. Further, in FIG. 5A, HLa illustrated in the organic EL element formation region ARel indicates an example of an opening formed at an arbitrary position of the cathode electrode 114 which is not illustrated, and EG1, ES1, ED1 represents a gate electrode, a source electrode, and a drain electrode of the thin film transistor Tr11, and EG2, ES2, and ED2 represent a gate electrode, a source electrode, and a drain electrode of the thin film transistor Tr12, respectively.

Next, a method for manufacturing a display pixel unit including the organic EL element OEL as described above will be briefly described.
FIG. 6 is a cross-sectional configuration diagram illustrating an example of a method for manufacturing a display pixel portion applied to the display device according to the present embodiment. Here, for the sake of illustration, only the cross section of the organic EL element formation region ARel and the thin film transistor Tr12 is shown.

  As shown in FIG. 6A, the manufacturing method of the display pixel unit according to the present embodiment is performed on the one surface side of a transparent insulating substrate 111 such as glass to be a panel substrate of the display panel 110A. Thin film transistors Tr11 and Tr12 constituting the pixel drive circuit DCA are formed in the pixel formation region. Here, an electrode layer to be the anode electrode 112 is formed in the organic EL element formation region ARel so as to be electrically connected to the drain electrode of the thin film transistor Tr12.

  Next, as shown in FIG. 6B, a partition wall 116 made of an insulating material is included so as to expose the anode electrode 112 formed in the organic EL element formation region ARel including the boundary region between adjacent display pixels EMA. Form. Here, the partition wall 116 is baked after a polyimide resin is applied to the entire area of one surface of the insulating substrate 111 on which the thin film transistor Tr12 and the anode electrode 112 are formed by a spin coating method, for example. . Thereafter, exposure, development, and cleaning are performed so that at least the anode electrode 112 in the organic EL element formation area ARel is exposed. Thereby, for example, a partition wall having a thickness of 7 μm is formed in the boundary region between the display pixels.

Next, as shown in FIG. 6C, a polymer-based hole transport material is laminated on the entire area of one surface of the insulating substrate 111 including the partition wall 116 and the anode electrode 112. As a result, a hole transport layer 113a having a thickness of, for example, 55 nm (550 mm) is formed on the anode electrode 112.
Furthermore, on the hole transport layer 113a of the organic EL element formation region 116 surrounded by the partition wall 116, for example, a polymer electron transporting light emitting material is applied by an ink jet method, and an electron having a thickness of 70 nm (700 mm) is applied. The transporting light emitting layer 113b is formed.

Next, as illustrated in FIG. 6D, a non-light-transmitting metal layer that becomes the cathode electrode 114 is stacked over the entire surface of the one surface of the insulating substrate 111. Here, the metal layer is formed by forming a barium (Ba) layer to a thickness of 1.5 nm (15 mm) by sputtering or the like, and then laminating an aluminum (Al) layer to a thickness of 500 nm (5000 mm). Thereafter, the metal layer is etched to form a cathode electrode 114 in the organic EL element formation region ARel, and a wiring portion (ground wiring) connected to the ground potential is formed integrally with the cathode electrode 114.
Thus, the anode electrode 112, the organic EL layer 113 (the hole transport layer 113a and the electron transport light emitting layer 113b), and the cathode electrode 114 were sequentially stacked in the organic EL element formation region ARel surrounded by the partition wall 116. An organic EL element OEL is formed.

  Next, an opening HLa is formed by etching so that the organic EL layer (electron transporting light emitting layer 113b) is exposed at an arbitrary position of the cathode electrode 114, and further, a translucent material is formed on the entire surface of the insulating substrate 111. After the sealing layer 117 made of a resin material is formed, the sealing pixel 118 is closely bonded to obtain a display pixel portion as shown in FIG. Here, as the sealing layer 117, for example, an epoxy-based light-transmitting resin material is laminated with a thickness of 0.05 mm, and as the sealing substrate 118, for example, a glass flat plate with a thickness of 0.1 mm is used. Join.

In the above-described manufacturing method, the case where a polyimide resist material is applied as the insulating material constituting the partition wall 116 has been described. However, the present invention is not limited to this, and a fluororesin, Other resin materials and the like can also be applied favorably.
Further, the partition wall 116 provided at the boundary portion between adjacent pixel formation regions is formed by using a light emitting material sprayed and applied by an ink jet method when forming the above-described electron transporting light emitting layer 113b. A process role for ensuring good formation (ie, the cathode electrode 114 is laminated with good consistency with respect to the anode electrode 112) without protruding, and extending on the partition wall 116; The cathode electrode 114 (including the ground wiring) formed in this manner and the thin film transistors Tr11 and Tr12 that form the pixel driving circuit DCA have a role in electrical characteristics that suppress capacitance components generated between the wiring layers.

  Further, the sealing layer 117 and the sealing substrate 118 are both those having a light transmittance of approximately 100%, so that a part of the light emitted from the organic EL layer 113 (back light LTb) is applied. Then, it can be taken out to the back side of the display panel 110 through the opening HLa provided in the cathode electrode 114, can be transmitted through the sealing layer 117 and the sealing substrate 118, and can be favorably propagated to the light guide plate 140. Here, the present invention is not limited to this configuration, and a chemical etching method or a laser processing method is applied to the sealing layer 117 and the sealing substrate 118 that are stacked on the opening HLa provided in the cathode electrode 114. Etc. is applied to form an opening and penetrate the opening HLa so that the organic EL layer 113 (electron transporting light-emitting layer 113b) is exposed on the back side of the display panel 110 through the opening. A configuration may be applied. According to this, the extraction efficiency of the back light LTb can be further improved. Note that in this case, the light-transmitting material does not have to be applied to the sealing layer 117 and the sealing substrate 118, and the degree of freedom in selecting materials and members can be improved.

  Here, in the configuration of the display pixel unit according to the present embodiment, in order to detect the light emission characteristic in each display pixel EMA (organic EL element), as described above, the opening HLa is formed at an arbitrary position of the cathode electrode 114. And a part of the light hν (back light LTb) is extracted on the back side of the display panel 110A. , It decreases according to the size and shape of the opening HLa.

  Therefore, in the present embodiment, by applying a configuration that improves the back light extraction efficiency as described below, the size of the opening provided in the cathode electrode is reduced and the amount of light emitted to the visual field side ( A small part of the light emitted from each display pixel can reach the light receiving sensor portion satisfactorily through the light guide plate provided on the back side of the display panel while suppressing the decrease in display light extraction efficiency as much as possible ( Incident). Here, as a technique for improving the extraction efficiency of light emitted from the organic EL layer, a structure based on the cathode electrode side in the organic EL element of the display pixel unit and a structure of the light guide plate disposed on the back side of the display panel Indicates that. These methods may be applied independently to the display device according to the present embodiment described above, or may be applied in combination.

  FIG. 7 is a schematic cross-sectional view showing a specific configuration example of the display pixel unit for improving the radiation light extraction efficiency according to the present embodiment. Here, about the structure equivalent to the display pixel part (refer FIG. 5) mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Further, in FIG. 7, the hatching of the sealing material is omitted in order to simplify the schematic optical path of the back light. In FIG. 7, the light guide plate is not shown, but is located above each figure. FIG. 8 is a schematic configuration diagram illustrating a specific configuration example of the light guide plate for improving the radiation light extraction efficiency according to the present embodiment.

  The first example of the display pixel unit for improving the extraction efficiency of the emitted light in the present embodiment is, for example, as shown in FIG. 7A, in the display pixel unit shown in FIG. On the back side (opposite side of the visual field side; upper side in the drawing) of the cathode electrode 114 constituting the light-transmitting resin material such as acrylic on the opening HLa formed in the cathode electrode 114 described above It has the structure which provided the condensing lens (condensing means) 119a formed by this.

  According to the display pixel unit having such a configuration, the back light LTb diffused and emitted to the back side of the display panel 110A through the opening HLa formed in the cathode electrode 114 of the organic EL element OEL is collected. Since the light can be converged by the optical lens 119a and incident on the light guide plate 140, even if the back light LTb extracted through the opening HLa is a small part of the light emitted from the organic EL element OEL, The back light LTb can efficiently reach the light receiving sensor unit 150 via the light guide plate 140 (with high extraction efficiency).

  Further, a second example of the display pixel unit for improving the extraction efficiency of the emitted light in the present embodiment is, for example, as shown in FIG. 7B, the back surface of the cathode electrode 114 constituting the organic EL element OEL. The non-translucent metal layer 119b is stacked and filled in a region on the side and surrounded by the partition wall 116 except for the top of the opening HLa formed in the cathode electrode 114, thereby forming the opening HLa. The light guide path (light collecting means) GHL is provided on the top.

  According to the display pixel portion having such a configuration, the back light LTb diffused and emitted to the back side of the display panel 110A through the opening HLa formed in the cathode electrode 114 is converted into a non-transparent metal. Since the light can be incident on the light guide plate 140 through the light guide path GHL formed in the layer 119b, the back light LTb radiated from the organic EL element OEL through the opening HLa can be efficiently passed through the light guide plate 140. Through the light receiving sensor unit 150.

  Furthermore, a third example of the display pixel unit for improving the extraction efficiency of the emitted light in the present embodiment is, for example, between the sealing substrate 118 and the light guide plate 140 (here, as shown in FIG. 7C). , A condensing lens (condensing light) formed of a light-transmitting resin material such as acrylic on at least a region on the opening HLa formed in the cathode electrode 114 on the upper surface of the sealing substrate 118. Means) It has a configuration provided with 119c.

  According to the display pixel unit having such a configuration, the back light LTb diffused and emitted to the back side of the display panel 110A through the opening HLa formed in the cathode electrode 114 is converged by the condenser lens 119c. Therefore, the back light LTb radiated from the organic EL element OEL through the opening HLa can efficiently reach the light receiving sensor unit 150 through the light guide plate 140. Can do. Here, FIG. 7C shows a configuration in which the condensing lens 119c having a projecting cross-sectional shape is individually provided corresponding to the formation region of each display pixel EMA (organic EL element OEL). The present invention is not limited to this, and applies a configuration in which a planar lens having a condensing function is interposed between the sealing substrate 118 and the light guide plate 140 (not shown). Also good.

  Moreover, the light guide plate for improving the extraction efficiency of the radiated light in the present embodiment is, for example, as shown in FIG. 8A, a light guide plate 140 disposed on the back side (downward in the drawing) of the display panel 110A. On the other side (the side opposite to the display panel 110A side), a plurality of micron-order groove portions (microprism array; light guide means) μPA having a wedge-shaped cross-sectional shape are formed in a predetermined arrangement pattern. Yes. Here, the wedge-shaped cross section constituting the groove μPA generally has a surface (vertical surface) PLa perpendicular to the other surface side of the light guide plate 140 and an inclined surface (inclined surface) PLb. As shown in FIG. 8B, each groove portion μPA corresponds to, for example, the arrangement of the display pixels EM arranged on the display panel 110A described above, and the inclined surface PLb of each groove portion μPA corresponds to the groove portion. In μPA, the light guide plate 140 is disposed so as to be perpendicular to the direction of the light receiving sensor unit 150 provided on the side end surface 140s of the light guide plate 140. The groove μPA is formed with a size of 3 μm, for example.

  According to the light guide plate 140 having such a configuration, the light is emitted from the display panel 110A to the back side (through the opening HLa formed in the cathode electrode 114 of the organic EL element OEL) and is incident on the light guide plate 140. The back light LTb is reflected in the direction of the light receiving sensor unit 150 on the inclined surface PLb of the groove μPA provided corresponding to each display pixel EMA, for example, and is repeatedly reflected in the light guide plate 140, so that the light guide plate 140 side Since the light is incident on the light receiving sensor unit 150 provided on the end surface 140s, a part of the light emitted from each display pixel EMA (organic EL element OEL) can reach the efficient light receiving sensor unit 150. The light emission characteristics of the organic EL element OEL can be detected well.

  Therefore, in the display device according to the present embodiment, as shown in FIG. 4, the light receiving surface is located on the side end surface at an arbitrary position on the side end surface 140 s of the light guide plate 140 disposed on the back side of the display panel 110 </ b> A. By providing the light receiving sensor part (light receiving element) 150 so as to oppose 140s, a part of the light emitted from the organic EL element OEL is displayed through the opening HLa formed in the cathode electrode 114. 110A is extracted as back light LTb on the back side of 110A, propagates in the light guide plate 140 (in the direction of the light receiving sensor unit 150), and is emitted from the organic EL element OEL by the light receiving sensor unit 150 provided on the side end surface 140s. It can be detected as an electrical signal corresponding to light.

  Here, as described above, the light receiving surface of the light receiving element is provided so as to oppose the side end surface 140s of the light guide plate 140, and as an adhesive that adheres and bonds the light guide plate 140 and the light receiving sensor unit 150 together. For example, an adhesive material having a refractive index continuous (optically continuous) is used at least. Accordingly, the light is preferably incident on the light receiving element from the light guide plate 140 through the side end face 140s. That is, the light receiving plate 140 and the light receiving sensor unit 150 are configured so that the light to be emitted from the side end surface 140s of the light guiding plate 140 can reach the light receiving sensor unit 150 side without reflection. Has been.

Next, a specific example of the light receiving sensor unit applicable to the above-described embodiment will be described.
FIG. 9 is a circuit diagram showing a specific example of the light receiving sensor unit applied to the display device according to the present embodiment.
For the light receiving sensor unit 150 applied to the present embodiment, for example, a configuration including a photodiode as a light receiving element can be applied.

  Specifically, as shown in FIG. 9, one end is connected to a high potential power supply (power supply voltage Vdd), the other end is connected to a contact N21, and one end is connected to a contact N21, and the other end is connected. A resistor Rp whose side is connected to the ground potential Vgnd, a reset signal Vreset, which will be described later, is applied to the gate terminal, an n-channel thin film transistor Tr23 whose source terminal and drain terminal are respectively connected to the contact N21 and the ground potential, and a gate terminal Is applied to the contact N21, the n-channel thin film transistor Tr21 having the source terminal connected to the high-potential power supply (Vdd), and the pixel selection signal Vdc described later is applied to the gate terminal, and the source terminal and drain terminal are the drain of the thin film transistor Tr21. An n-channel type thin film transistor Tr22 connected to each of the terminal and the detection terminal TMf, Can be applied to the example was circuitry.

  Here, the pixel selection signal Vdc is a control signal that is set to a high level state in synchronization with at least the timing at which the display pixel EMA (organic EL element OEL), which is a measurement target of light emission luminance, enters a light emission state. The reset signal Vreset is set to a high level every time the light emission luminance measurement operation in each display pixel EMA is completed (or prior to the light emission luminance measurement operation), and the charge accumulated at the contact N21 is set to the ground potential. This is a control signal that is discharged to Vgnd and initialized. These control signals Vdc and Vreset are generated by, for example, the correction control circuit 160 or the system controller 170 described above and applied to the light receiving sensor unit 150 at a predetermined timing. The detection terminal TMf is connected to an amplifier AMP provided in a correction control circuit 160 described later.

<Display device drive control method>
Next, a drive control operation (drive control method) in the display device having the above-described configuration will be specifically described with reference to the drawings.
FIG. 10 is a timing chart showing an example of the specific amount detection operation applied to the display device drive control method according to the present embodiment.

  The drive control method in the display device according to the present embodiment includes an image display operation for displaying desired image information on the display panel 110A and a normal image display operation based on a video signal supplied from the outside of the display device 100A. Prior to, for example, a specific amount corresponding to the light emission characteristics of each display pixel EM (at the time of turning on the power to the display panel 110A or at an appropriate timing after the image display operation has elapsed for a predetermined time) (Luminance Luminance) is detected and held as digital gradation data, and the correction value is based on the digital gradation data (detection gradation data) acquired by the specific amount detection operation during the image display operation. Correction operation for correcting display data (digital signal) supplied from the display signal generation circuit 160 to the data driver 130A , It contains. Hereinafter, each operation will be described. The execution timing of the specific amount detection operation will be described later.

(Specific amount detection operation)
First, in the specific amount detection operation according to the present embodiment, at least a correction control signal for executing a specific amount capturing and holding operation in the correction control circuit 160 is supplied from the system controller 170, and the gate driver 120A and the data driver In 130A, it is executed by supplying a scanning control signal and a data control signal for executing the following operation.

  In the specific amount detection operation, as shown in FIG. 10, the reset signal Vreset is first received based on the correction control signal supplied from the system controller 170 to the correction control circuit 160 at a timing prior to the supply of the scanning control signal. Applied to the sensor unit 150. Accordingly, the thin film transistor Tr23 provided in the light receiving sensor unit 150 illustrated in FIG. 9 is turned on, and a reset operation is performed in which the potential of the gate terminal (contact N21) of the thin film transistor Tr21 is set to the ground potential Vgnd.

  Next, at a timing based on the scan control signal supplied from the system controller 170, the gate driver 120A continues the high level scan signal Vscan1 to the first scan line SL1 for a predetermined period (for example, one horizontal scan period). By applying, the thin film transistor (select transistor) Tr11 provided in the pixel drive circuit DCA of each display pixel EMA connected to the scanning line SL1 is turned on, and the display pixel group in the row is set to the selected state. At this time, the pixel selection signal Vdc is applied to the light receiving sensor unit 150 in synchronization with the timing at which the scanning signal Vscan1 is applied to the scanning line SL1, so that the thin film transistor Tr22 provided in the light receiving sensor unit 150 is also turned on. The detection standby state in which the detection data from the photodiode PD can be taken out is set.

  Next, in this selection state (selection period), for example, the highest gradation display (light emission operation at the highest gradation level) is performed only for the display pixels in the first column as luminance detection data for the data driver 130A. In addition, for display pixels in other columns, for example, serial data (display data) composed of digital signals for performing the lowest gradation display (light emission operation at the optimum gradation level; black display operation) Is supplied. As a result, the data driver 130A has a gradation based on the maximum gradation voltage (MSB) at the timing based on the data control signal supplied from the system controller 170, as shown in FIG. One row set to a selected state via each data line DL by generating the signal voltage (specific gradation signal) Vdata1 and gradation signal voltages Vdata2 to VdataM composed of the lowest gradation voltage (Vgnd). Applied to the display pixel group of the eye all at once.

  Thereby, the gradation signal voltages Vdata1 to VdataM applied to each data line DL are applied to the gate terminal of the thin film transistor Tr12 via the thin film transistor Tr11 of the pixel drive circuit DCA provided in each display pixel. Only the thin film transistor Tr12 provided in the pixel driving circuit DCA of the display pixel in the first row and first column is turned on in a conductive state according to the gate voltage (that is, the gradation signal voltage Vdata1), and the display pixels in other columns The thin film transistor Tr12 is turned off.

  Accordingly, only in the thin film transistor Tr12 provided in the pixel driving circuit DCA of the display pixel in the first row and first column, the potential difference between the high potential power supply (power supply voltage Vdd) and the ground potential Vgnd and the voltage value of the gradation signal voltage Vdata1. Accordingly, a light emission driving current flows from the high potential constant power supply (power supply voltage Vdd) side to the ground potential Vgnd through the thin film transistor Tr12 and the organic EL element OEL, and the organic EL element OEL has a luminance level corresponding to the highest gradation level. The organic EL elements OEL of the display pixels in other columns maintain a non-light emitting state.

  In the display pixel EMA in the first row and first column, the light of the highest gradation level emitted from the organic EL element OEL is transmitted through the transparent insulating substrate 111 constituting the display panel 110A and displayed on the view side. While being emitted as light LTf, it is emitted as back light LTb through the opening HLa formed in the cathode electrode 114 of the organic EL element OEL, and propagates through the light guide plate 140 disposed on the back side of the display panel 110A. Then, the light enters the light receiving sensor unit 150 (photodiode PD) installed so that the light receiving surface faces the side end surface 140s of the light guide plate 140. As a result, a signal current corresponding to the intensity of the light (light receiving intensity; corresponding to the light emission luminance of the organic EL element OEL) flows from the power supply voltage Vdd to the ground potential Vgnd via the photodiode PD and the resistor Rp, and the contact N21 ( That is, a voltage corresponding to the received light intensity is generated at the gate electrode of the thin film transistor Tr21 functioning as an amplification transistor.

As a result, the thin film transistor Tr21 is turned on in a conductive state corresponding to the voltage (light receiving intensity), so that the photodiode is supplied from the power supply voltage Vdd to the correction control circuit 160 via the thin film transistors Tr21 and Tr22 and the detection terminal TMf. Detection data (analog signal current) having a signal level corresponding to the light reception intensity of the PD, that is, the light emission luminance of the organic EL element OEL is input.
As described above, this detection data is amplified to a predetermined signal level by the amplifier AMP, then converted to a digital signal by the A / D converter ADC, and the digital gradation data is stored in a predetermined storage area of the storage unit BM. Stored as (detected gradation data).

Next, as in the case of the luminance detection operation in the display pixel in the first row and first column described above, the potential of the gate terminal (contact N21) of the thin film transistor Tr21 is grounded by applying the reset signal Vreset to the light receiving sensor unit 150. The potential is reset to Vgnd.
Next, in the display pixel group set in the selected state, the highest gradation display is performed only for the display pixels in the second column, and the lowest gradation display is performed for the display pixels in the other columns. By supplying the luminance detection data to be performed to the data driver 130A, as shown in FIG. 10, only the second column data line DL2 is the same as the first column display pixel as described above. A gradation signal voltage Vdata2 composed of a gradation voltage (MSB) is applied, and gradation signal voltages Vdata1, Vdata3 to VdataM composed of a minimum gradation voltage (Vgnd) are applied to the other data lines. .

As a result, the organic EL element OEL provided in the pixel drive circuit DCA of the display pixel EMA in the first row and second column emits light at the highest gradation level based on the gradation signal voltage Vdata2, and other columns. Since the organic EL element OEL of the display pixel EMA maintains the non-light emission state, the light emission luminance of the organic EL element OEL in the display pixel EMA in the first row and the second column is detected by the light receiving sensor unit 150. Detection data having a signal level corresponding to the signal level is output to the correction control circuit 160 via the detection terminal TMf, converted into a digital signal, and stored as digital gradation data in a predetermined storage area of the storage unit BM.
Hereinafter, the specific amount detection operation (reset operation, light emission operation, and luminance detection operation) in each display pixel is sequentially repeated for the display pixels EMA in each row and each column, whereby all of the display panel 110A is configured. A specific amount corresponding to the light emission characteristic in the display pixel EMA (organic EL element OEL) can be acquired as digital gradation data.

Here, the specific amount detection operation shown in the present embodiment may be executed in advance at an arbitrary timing prior to an image display operation to be described later, or when the display device is activated or terminated, an image display is performed. It may be executed regularly or irregularly, such as during a standby time other than when the operation is executed. An example of the execution timing of the specific amount detection operation will be described later.
Further, in the present embodiment, a case has been described in which display data corresponding to the highest gradation level is supplied to the data driver 130A as luminance detection data, and the corresponding gradation signal voltage Vdata is supplied to each display pixel. However, the present invention is not limited to this, and the organic EL element OEL of each display pixel is caused to emit light at a luminance gradation corresponding to another gradation level, and the emission luminance is detected. May be.

  Furthermore, in the present embodiment, the configuration for supplying the luminance detection data to the data driver 130 during the specific amount detection operation is not particularly limited, but for example, a predetermined value of the storage unit BM provided in the correction control circuit 160 The luminance detection data may be stored in the storage area in advance and read as appropriate, or the luminance detection data may be read by the display signal generation circuit 180 or from the outside of the display device 100A via the display signal generation circuit 180. It may be supplied.

(Execution timing of specific amount detection operation)
Next, timing for executing the above-described specific amount detection operation will be described.
FIG. 11 is a flowchart illustrating an example of a drive control operation related to the specific amount detection operation according to the present embodiment.
For example, as illustrated in FIG. 11, the specific amount detection operation according to the present embodiment is performed immediately after the power is turned on to the display panel 110A and at a timing prior to the subsequent normal image display operation. (S101, S102). In this case, for example, it is performed at a timing prior to the start of use of an electronic device or the like provided with the display panel 110A (display device 100A). The timing is not limited to when the power to the electronic device main body is turned on. For example, the power supply to the display panel 110A is cut off when the electronic device is in use, and the display is turned off. It may be a timing immediately after the display is started after the power supply to the display panel 110A is turned on again after entering the use state. By performing the specific amount detection operation at these timings, it is possible to perform the specific amount detection operation without hindering the usability of the electronic device, and to favorably correct the gradation signal voltage Vdata.

Next, as shown in FIG. 10, the specific amount detection operation according to the present embodiment is also executed at a timing after a normal image reading device display operation by the display panel 110A is performed (S103) and a predetermined time has elapsed. You may make it do (S104, S105). That is, the specific amount detection operation is performed at predetermined time intervals during the image display operation, and the gradation signal voltage is corrected as needed (S103 to S105). Here, the time interval for executing the specific amount detection operation Is set to an appropriate time according to the degree of deterioration of the characteristics of the light emitting element (organic EL element OEL) used for the display pixel. Further, in this case, in order to avoid switching to the specific amount detection operation state during use of the electronic device or the like provided with the display panel 110A, for example, the electronic device is in a standby state after a predetermined time has elapsed. Sometimes, a specific amount detection operation may be performed.
In the execution timing, the specific amount detection operation is performed immediately after the power is turned on to the display panel 110A (display device 100A) and after a predetermined time elapses after the normal image display operation is performed. However, it may be executed only at one of the timings.

(Image display operation / data correction operation)
Next, the normal image information display operation and data correction operation in the present embodiment will be described.
FIG. 12 is a timing chart illustrating an example of an image display operation applied to the display device drive control method according to the present embodiment. Here, the operation equivalent to the above-described specific amount detection operation will be described in a simplified manner.

  In the normal image display operation in the present embodiment, at least the specific amount detection operation from the system controller 170 to the correction control circuit 160 is stopped in the display device shown in FIGS. A correction control signal for executing a data correction operation for correcting display data from 180 is supplied, and a scan control signal for executing the following operation for the gate driver 120A and the data driver 130A. And a data control signal is supplied.

  In the image display operation, first, display data for one row is displayed by the display signal generation circuit 180 (display data corresponding to the display pixel group in the i-th row of the display panel 110A having n rows × m columns; 1 ≦ i ≦ n). ) Is supplied to the data driver 130 </ b> A via the comparison correction unit CMR of the correction control circuit 160. Here, the display data output from the display signal generation circuit 180 is, for example, serial data including a digital signal generated based on a video signal supplied from the outside of the display device 100A. Degradation of light emission characteristics of the display pixels EMA constituting the display panel 110A (that is, due to temporal changes and variations in element characteristics of the thin film transistors Tr11 and TR12 and the organic EL elements OEL constituting the pixel drive circuit DCA provided in each display pixel EMA) This does not take into account the resulting variation in emission luminance of the organic EL element OEL.

  Therefore, in the image display operation according to the present embodiment, after an arbitrary time has elapsed after the factory shipment of the electronic apparatus or the like to which the display device is applied, the specific amount detection operation described above acquires and is stored in the storage unit BM. A specific amount according to the light emission characteristics of each display pixel EMA (digital gradation data according to the light emission luminance of the organic EL element OEL when a specific gradation signal voltage is applied; detection gradation data), for example, a factory The initial value obtained by the above-described specific amount detection operation at the time of shipment and stored in the storage unit BM in advance, and the organic EL element OEL at the gradation signal voltage corresponding to the display data supplied in the image display operation. A specific amount corresponding to the light emission characteristic (initial value of light emission luminance of the organic EL element OEL when a specific gradation signal voltage is applied; initial gradation data) Based on the comparison result, a correction value (digital value) is generated so that the light emission luminance of each display pixel EMA (organic EL element OEL) approximates the initial light emission luminance. A process of correcting display data for each display pixel EMA to be supplied is executed based on the correction value and supplied to the data driver 130 as corrected data (data correction operation).

The data driver 130A generates a gradation signal voltage Vdata corresponding to each display pixel EMA in the i-th row based on the corrected data supplied via the correction control circuit 160 (comparison correction unit CMR), It is applied simultaneously to the data lines DL in each column.
At this time, as shown in FIG. 12, by applying a high level scanning signal Vscani to the i-th scanning line SLi by the gate driver 120A, the pixel driving of each display pixel EMA in the row shown in FIG. The thin film transistor (selection transistor) Tr11 provided in the circuit DCA is turned on, and a gate voltage based on the gradation signal voltage Vdata applied to each data line DL is applied to the gate terminal of the thin film transistor (light emission drive transistor) Tr12. Then, it is turned on in a conductive state corresponding to the gate voltage.

  Thereby, the thin film transistor Tr12 of the display pixel group in the i-th row (for example, the display pixel EMA in the i-th row and j-th column; 1 ≦ j ≦ m) from the high potential power supply (power supply voltage Vdd) side through the power supply line VL A light emission driving current having a current value based on the gradation signal voltage Vdataj flows through the organic EL element OEL, and the organic EL element OEL has a predetermined luminance based on display data (strictly, corrected data obtained by correcting display data). The light emission operation is performed (selection period Tse). At this time, the gate-source parasitic capacitance Ca is charged by the potential difference generated between the gate and the source of the thin film transistor Tr12. Here, since the gradation signal voltage Vdata applied to each display pixel EMA is set (corrected) based on the initial light emission luminance of the light emitting element by the data correction operation, each organic EL element. The OEL emits light with a luminance gradation approximate to the initial state.

Next, as shown in FIG. 12, a low-level scanning signal Vscani is applied to the i-th scanning line SLi by the gate driver 120A, and the thin film transistor Tr11 provided in the pixel driving circuit DCA of the display pixel group in the row is changed. By turning off, the application of the gradation signal voltage Vdatai to the gate terminal of the thin film transistor Tr12 is cut off. At this time, the potential difference applied between the gate and the source of the thin film transistor Tr12 during the selection period Tse is held as a voltage component in the parasitic capacitance Ca, so that the thin film transistor Tr12 maintains the on state by this voltage component, The light emission drive current equivalent to the selection period Tse flows through the thin film transistor Tr12 and the organic EL element OEL of each display pixel in the i-th row, and continues the operation of emitting light with a luminance gradation approximate to the initial state (non-selection period Tnse). .
The selection period Tse and non-selection period Tnse set in such an image display operation have a sum (total time) of, for example, one frame period that is an operation period for displaying image information for one screen on the display panel 110A. It is set to be Tcyc.

Hereinafter, similarly, as for the display pixel group in the (i + 1) th row, as shown in FIG. 12, the scanning signal Vscan (i + 1) is applied to the scanning line SL (i + 1) in the selection period Tse. Thus, the gradation signal voltage Vdata based on the corrected display data (corrected data) is applied to each display pixel in the row via the data line DL in each column, and the organic EL element OEL performs a light emission operation. At the same time, the voltage component accompanying the light emission operation is held in the parasitic capacitance Ca. In the non-selection period Tnse, an operation in which each display pixel EMA (organic EL element OEL) in the row emits light with a predetermined luminance gradation based on the voltage held in the parasitic capacitance Ca of each display pixel EMA. Maintained.
By sequentially repeating a series of image display operations including such a data correction operation for each row, image information for one screen is displayed on the display panel 110.

  Therefore, according to the display device and the drive control method thereof according to the present embodiment, prior to the normal image display operation, or at any timing other than the image display operation (when the display device is activated, at the standby time, etc.) By executing a specific amount measurement operation, digital gradation data corresponding to light emission characteristics (light emission luminance) in each display pixel (organic EL element) with respect to application of a specific gradation signal voltage based on luminance detection data And a correction value corresponding to the light emission characteristic of each display pixel is generated as needed based on the digital gradation data (that is, generated based on the corrected data corrected based on the correction value). With the gradation signal voltage, a correction value can be set in advance so that the light emission luminance obtained when the light emitting element of each display pixel performs a light emission operation approximates the initial light emission luminance.

  Thus, in a normal image display operation, the display data supplied to the data driver is subjected to correction processing based on the correction value, and the light emission characteristics of each display pixel (that is, the pixel driving circuit provided in each display pixel) The data correction operation is performed to correct the digital data (corrected data) according to the change in the light emission luminance of the organic EL element due to the time-dependent changes and variations in the element characteristics of the thin film transistors and organic EL elements that constitute the gray scale signal. Since a voltage can be generated and applied to each display pixel, the relationship of the light emission luminance of the organic EL element (light emitting element) to the luminance gradation specified by the display data is always maintained in a state that approximates the initial state. It is possible to correct the deterioration and variation of the light emission characteristics of each display pixel (light emitting element), and to make the image information good and stable over a long period of time. It can be displayed.

  In the present embodiment, as the specific amount detection operation, the case where the light emission luminance in each display pixel is detected by the luminance detection data having only a single gradation level (maximum gradation level) has been described. The present invention is not limited to this. For example, by supplying luminance detection data corresponding to a plurality of gradation levels, the organic EL element of each display pixel is caused to emit light at different luminance gradations. The luminance in the light emission state (luminance gradation) is detected, and the detected gradation data under a plurality of gradation conditions is acquired for each display pixel (organic EL element) and held in the correction control circuit (storage unit). It may be.

  As a result, in the image display operation and data correction operation described above, the light emission characteristics of the display pixel (organic EL element) can be displayed regardless of the temporal changes and variations in the element characteristics of the thin film transistors and organic EL elements constituting the pixel drive circuit. The relationship of the light emission luminance of the organic EL element (light emitting element) to the luminance gradation specified by the data can always be maintained close to the initial state, and the image information can be displayed with good and stable image quality over a long period of time. Can do.

  Further, in the present embodiment, a specific amount detection operation for detecting light emission luminance by specific luminance detection data is sequentially executed for all the display pixels constituting the display panel, and each display pixel is held in the storage unit. The case where the detected gradation data and the initial gradation data previously stored for each display pixel are compared, and a correction value is generated for each display pixel to execute a data correction operation for correcting the display data is described. However, the present invention is not limited to this.

For example, when the change tendency (deterioration tendency) of the element characteristics of the light emitting elements (organic EL elements) of each display pixel is almost uniform, for example, every other pixel or every few pixels, The specific amount detection operation and the data correction operation described above may be executed only for the selected display pixel, or the detected gradation data and the initial gradation obtained for the appropriately selected display pixel. A data correction operation is performed so as to correct display data supplied to each of all the display pixels constituting the display panel based on an average value or a change tendency of correction values obtained based on the data. There may be.
According to this, during the specific amount detection operation and the data correction operation, the amount of data to be processed can be greatly reduced, so that the processing load on the correction control circuit, the system controller, etc. is reduced, and the correction processing is performed. It is possible to reduce the time involved in

  Furthermore, in the above-described embodiment, the light receiving sensor unit (light receiving element) is disposed only in the vicinity of the approximate center of one side end surface of the transparent insulating flat plate constituting the light guide plate disposed on the back side of the display panel. Although the configuration (see FIG. 4A) is shown, the present invention is not limited to this, and a light guide plate formed by any position of the side end surfaces, for example, two adjacent side end surfaces. You may arrange | position in the position of the corner | angular part vicinity, etc.

  In short, the present invention detects a part of the back light which is taken out from the back side of the display panel and propagates in the light guide plate among the light emitted from the organic EL layer by the light receiving sensor unit (light receiving element). Since a specific amount related to the light emission characteristics of the organic EL element (light emitting element) is detected, the light receiving surface is provided at an arbitrary position where the back light can be favorably received. I just need it. In particular, as shown in FIG. 8, in the case of applying a configuration in which minute grooves (prism arrays) are arranged on the light guide plate, the shape and arrangement pattern of the grooves can be set as appropriate. The back light can be efficiently propagated to the light receiving sensor unit disposed at an arbitrary position on the end face.

(Another configuration example of the display pixel portion)
Next, another configuration example of the display pixel portion (opening) applied to the display device according to the present invention will be described with reference to the drawings.
FIG. 13 is a configuration diagram showing another configuration example (circuit layout and cross-sectional structure) of the display pixel portion applied to the display device according to the present invention. Here, about the structure equivalent to the display pixel part shown in FIG. 5, the same code | symbol is attached | subjected and the description is simplified or abbreviate | omitted.

  Another configuration example of the display pixel EMA ′ applicable to the display device according to the present invention is surrounded by the scanning line SL, the data line DL, and the power supply line VL as shown in FIGS. In the pixel formation region, an anode electrode 112, an organic EL layer 113 (a hole transport layer 113a, an electron transport light emitting layer 113b), and a cathode electrode 114 are sequentially stacked on the organic EL element formation region ARel defined by the partition wall 116. The cathode electrode 114 and the partition wall 116 in a part of the region where the partition wall 116 is formed are etched away from a partial region of the edge portion of the organic EL element OEL to be a part of the organic EL layer 113 and the partition wall 116. The opening HLb from which a part of the thin film transistor Tr12 formed in the lower layer is exposed is formed. That is, a part of the light directly emitted from the organic EL layer 113 and a part of the light emitted toward the side surface of the organic EL layer 113 and diffused to the thin film transistor Tr12 side are taken out through the opening HLb. It is comprised as follows.

  Similarly to the display pixel portion shown in FIG. 5, the entire region on the insulating substrate 111 including the organic EL element OEL in which the opening HLb is formed and the partition wall 116 is formed with a light-transmitting sealing layer 117 and A light guide plate (not shown) 140 is disposed by being sealed by the sealing substrate 118 and spaced apart from the sealing substrate 118, or the light guide plate (not shown) 140 is in close contact with the sealing substrate 118. It is joined.

  According to the display pixel unit having such a configuration, a part of light emitted from the organic EL layer 113 of the organic EL element OEL is separated from the cathode electrode 114 into the partition wall, as in the above-described embodiment (see FIG. 5). 116 can be extracted as back light through an opening HLb formed to extend to the formation region 116 and can enter the light guide plate 140 disposed on the back side of the display panel 110A. Light corresponding to the light emission luminance of the display pixel EMA ′ (organic EL element OEL) can be detected by the light receiving sensor unit 150 provided so that the light receiving surface faces the end surface 140s. In this case, since a part of the light directly emitted from the organic EL layer 113 and a part of the light diffused in the side surface direction of the organic EL layer 113 are taken out, the structure shown in FIG. As compared with the above, the area of the organic EL layer 113 exposed through the opening HLb can be further reduced, and the reduction in display light extraction efficiency can be further suppressed.

Next, still another relationship between the light guide plate and the light receiving sensor portion applied to the display device according to the present invention will be described with reference to the drawings.
In each of the above-described embodiments, as shown in FIG. 4, the configuration in which the only light receiving sensor unit (light receiving element) 150 is provided in close contact with the one side end surface 140 s of the light guide plate 140 is shown. The present invention is not limited to this, and may include a plurality of light receiving sensor portions (light receiving elements) as shown below.

  FIG. 14 is a schematic perspective view showing another relationship between the display panel and the light receiving sensor unit applied to the display device according to the present invention. Here, regarding the relationship between the light guide plate and the light receiving sensor unit, the schematic cross-sectional view shown in FIG. FIG. 15 is a schematic perspective view showing another relationship between the display panel, the light guide plate, and the light receiving sensor unit applied to the display device according to the present invention.

  In the configuration example shown in FIG. 14A, two opposing side end surfaces (the right and left end surfaces in the drawing) of the light guide plate 140 (see FIG. 4B) disposed on the back side of the display panel 110A. ) Has a configuration including two light receiving sensor portions 150a and 150b, one each. In addition, in the configuration example shown in FIG. 14B, a total of four light receiving sensor portions 150c to 150f, one for each side end surface (left and right side in the drawing and front and rear end surfaces) of the light guide plate 140, one each. It has the composition provided with.

  In this way, by installing the light receiving sensor part (light receiving element) in close contact with each of a plurality of different side end surfaces, the back light from the light emitted from the specific display pixel (organic EL element) is more Since many (that is, the number of light receiving sensor units installed) can be captured and detected, the influence of noise other than light emitted from the specific display pixel being measured is suppressed, and a correction control circuit Thus, the reliability of the detection data captured in the image data can be increased, and more accurate display data correction processing can be realized.

  In the configuration example shown in FIG. 14C, the light receiving sensor unit 150g formed of a sensor substrate in which a plurality of light receiving elements are arranged in a one-dimensional array is connected to a specific side end face ( It has a configuration in which it is installed in close contact only with the front end face of the drawing. Here, in the plurality of light receiving elements provided in the light receiving sensor unit 150g, each light receiving surface is opposed to a specific side end surface of the light guide plate 140, as in the configuration shown in FIG. In addition to being formed, the light receiving sensor unit 150g and the light guide plate 140 are configured to be optically continuous by being bonded via a predetermined adhesive.

  In this way, a specific display pixel (organic EL) can be formed in the same manner as in the configuration example described above by closely attaching a light receiving sensor unit in which a plurality of light receiving elements are formed in an array only on a specific side end surface. Since more light emitted from the element) can be detected, the reliability of detection data taken into the correction control circuit can be improved, and more accurate display data correction processing can be executed. In addition, since a plurality of light receiving elements are formed in an array, it is possible to simplify the work of attaching the light receiving sensor part to the side end face of the insulating substrate and reduce the number of parts and reduce the product cost. Can be achieved.

  FIG. 14C shows a configuration in which a light receiving sensor unit in which a plurality of light receiving elements are arranged one-dimensionally is provided only on a specific side end surface. Similarly to the case, it may have a configuration in which an equivalent light receiving sensor portion is provided on each of two opposing surfaces or all side end surfaces. Further, in FIG. 14C, the case where a plurality of light receiving elements are formed in an array on a substrate by applying thin film technology has been described, but the present invention is not limited to this. Individual light receiving sensor parts (substrates) having a single light receiving element as shown in FIG. 4 (a) or FIG. 14 (a) are spaced apart from each other on the same side end surface, or A plurality may be arranged in close contact with each other.

  In the configuration shown in FIGS. 14A to 14C, a plurality of light receiving sensor portions are arranged on the side end surface of the light guide plate, so that more back light emitted from a specific display pixel is received. Therefore, the structure of the light guide plate 140 is a normal insulating flat plate (that is, a groove (prism array) μPA as shown in FIG. 8 is not formed. A light guide plate as shown in FIG. 4 can be applied.

  Furthermore, in the relationship between the display panel shown in FIGS. 4 and 14 described above, the light guide plate, and the light receiving sensor unit, the light receiving sensor unit 150 is formed in a substrate shape by applying thin film technology, and a predetermined side of the light guide plate Although the configuration provided so as to be in close contact with the side end surface is shown, the present invention is not limited to this. For example, as shown in FIG. An arcuate recess 142a is formed, or as shown in FIG. 15 (b), an arcuate recess 142b is formed at a corner formed by any side end surfaces of the light guide plate 140, and the recess 142a, A configuration in which a light receiving sensor unit (light receiving element) 150 formed in a columnar shape is provided so as to face 142b may be applied. Here, the light-receiving surface of the light-receiving sensor unit (light-receiving element) 150 is disposed so as to face the end surfaces of the arc-shaped concave portions 142a and 142b.

  According to this, a part of the light radiated from the organic EL layer 113 and extracted as back light through the opening provided in the cathode electrode 114 and reflected and propagated in the light guide plate 140 is arc-shaped. The light is emitted from the end surfaces of the recesses 142a and 142b toward the light receiving sensor unit 150 disposed at the center of the arc, so that more light is received from the light guide plate 140 and the organic EL element OEL emits light. Detection data corresponding to brightness can be obtained, and more appropriate display data correction processing can be performed.

  In addition, in the above-described embodiment and each configuration example, only the circuit configuration in which the photodiode PD as shown in FIG. 14 is applied as the light receiving element is shown as the light receiving sensor unit 150. However, the present invention is not limited to this. As long as the electrical signal to be output changes depending on the intensity and the amount of light received, for example, other photoconductive sensors and double gate type photo sensors as shown below It goes without saying that a light receiving element may be applied.

Hereinafter, a light receiving element (photoconductive sensor, double gate type photosensor) applicable to the display device according to the present invention will be briefly described with reference to the drawings.
FIG. 16 is a cross-sectional configuration diagram of a light receiving element and a circuit diagram of the light receiving sensor portion showing another specific example of the light receiving sensor portion applied to the display device according to the present invention. In FIG. 16, the case where a photoconductive sensor is applied as a light receiving element which comprises a light receiving sensor part is demonstrated.

  The light receiving element applied to the light receiving sensor unit according to this specific example is a well-known photoconductive sensor, and schematically shows a light-shielding lower electrode layer 31 and a light-transmissive upper part as shown in FIG. The photoconductive layer 32 has a structure in which the photoconductive layer 32 is interposed between the photoconductive layer 32 and the photoconductive layer 32 is irradiated with light through the upper electrode layer 33. The resistance value changes (decreases) and the current value flowing between the electrode layers 31 and 33 changes. The photoconductive sensor PR is set so that the translucent upper electrode layer 33 side is in close contact with the light receiving surface facing the side end surface 140s of the light guide plate 140 disposed on the back side of the display panel 110A. Yes.

  Here, as the photoconductive layer 32 constituting the photoconductive sensor PR, for example, an amorphous silicon-based material, a selenium-based material, or the like can be favorably applied. In addition, as other photoconductive materials, organic materials obtained by doping (mixing) photoconductive dyes into materials such as polyvinyl carbazole and host polymers can be favorably applied. The photoconductive sensor PR as described above is laminated on the light-shielding substrate 34, and the periphery of the photoconductive sensor PR is covered with the light-transmitting insulating layers 35 and 36. Yes.

  Then, as shown in FIG. 16B, for example, the light receiving sensor unit according to this specific example includes the photoconductive sensor PR as described above between the voltage source of the predetermined sense voltage Vsens and the detection terminal TMf. The current path of the n-channel type thin film transistor Tr31 is connected in series, and the gate terminal of the thin film transistor Tr31 is controlled in synchronization with the light emission state of the display pixel (light emitting element) whose light emission luminance is to be measured. A circuit configuration to which the selection signal Vdc is applied can be applied.

  Thereby, a part of the light emitted by the light emitting operation of the specific display pixel (light emitting element) is extracted to the back side of the display panel 110A, propagates in the light guide plate 140, and is lateral to the light guide plate 140. By making the light receiving sensor unit 150 (the photoconductive layer 32 through the upper electrode of the photoconductive sensor PR) provided as the light receiving surface facing the end surface 140s as the back light LTb, the intensity of the incident light ( The resistance value of the photoconductive sensor PR decreases in accordance with the (received light intensity). At this time, the high-level pixel selection signal Vdc is applied in synchronization with the light emission operation of the specific display pixel, so that the thin film transistor Tr31 of the light receiving sensor unit 150 is turned on, so that light from the voltage source of the sense voltage Vsens is emitted. The current flowing through the conductive sensor PR and the thin film transistor Tr31 is output as detection data to the correction control circuit 160 (amplifier AMP) through the detection terminal TMf. Here, the current output as detection data has a current value corresponding to the light emission luminance in a specific display pixel.

  Therefore, according to the display device provided with the light receiving sensor unit having such a configuration, the structure of the light receiving element constituting the light receiving sensor unit can be simplified and thinned. Compared to the configuration of a sensor unit (see FIG. 9) and a light receiving sensor unit (see FIG. 17) to which a double gate type photosensor described later is applied, the size of the apparatus is greatly reduced and the manufacturing process is simplified. , Improvement in yield, and reduction in variation in sensor characteristics can be achieved, and a display device with good display quality can be realized with a small size and low cost.

  FIG. 17 is a cross-sectional configuration diagram of a light receiving element and a circuit diagram of the light receiving sensor unit showing still another specific example of the light receiving sensor unit applied to the display device according to the present invention. In FIG. 17, a case where a double gate type photosensor is applied as a light receiving element constituting the light receiving sensor unit will be described. FIG. 18 is a timing chart showing a basic drive control method of the light receiving sensor unit (light receiving element) in this specific example.

The light receiving element applied to the light receiving sensor unit according to this specific example is a photosensor having a so-called double gate type transistor structure (double gate type photosensor). As schematically shown in FIG. Here, a semiconductor layer (channel region) 41 such as amorphous silicon in which electron-hole pairs are generated by incidence of visible light, and an impurity layer (ohmic contact layer) made of n ⁺ silicon on both ends of the semiconductor layer 41, respectively. ) 47, 48, and made of a conductive material selected from chromium, chromium alloy, aluminum, aluminum alloy, etc., and is opaque to visible light source electrode 42 (source terminal S) and drain electrode 43 ( The drain terminal D) and the semiconductor layer 41 (above the drawing) with a block insulating film (stopper film) 44 and a top gate insulating film 45 interposed therebetween. A top gate electrode TG (first gate electrode; top gate terminal) which is formed of a transparent electrode layer such as a tin oxide film or an ITO film (indium-tin oxide film) and is transparent to visible light; The bottom is formed below the semiconductor layer 41 (downward in the drawing) via the bottom gate insulating film 46, and is made of a conductive material selected from chromium, chromium alloy, aluminum, aluminum alloy, etc., and is opaque to visible light. And a gate electrode BG (second gate electrode; bottom gate terminal). The double-gate photosensor PW having such a configuration is formed on an insulating substrate SUB as shown in FIG. A protective insulating film (passivation film) 49 is formed on the entire surface of the one surface side of the insulating substrate SUB including the double-gate photosensor PW.

  In FIG. 17A, at least the top gate insulating film 45, the insulating film constituting the block insulating film 44, and the protective insulating film 49 provided on the top gate electrode TG all excite the semiconductor layer 41. It is made of a material having a high transmittance with respect to visible light, such as silicon nitride or silicon oxide. Here, the double gate type photosensor PW has a light receiving surface on the side end surface 140s of the light guide plate 140 disposed on the back side of the display panel 110 on the top gate electrode TG side (for example, the upper surface of the protective insulating film 49). It is installed so as to be in close contact with each other.

  The light receiving sensor unit 150 according to this specific example includes a double gate as described above between a predetermined power supply voltage (low potential power supply) Vss and the detection terminal TMf, as shown in FIG. The current paths of the photosensor PW and the n-channel thin film transistor Tr41 are connected in series with each other, and a connection point between the double-gate photosensor PW and the n-channel thin film transistor Tr41 and a predetermined precharge voltage Vpg. A circuit configuration in which a current path of an n-channel thin film transistor Tr42 is connected therebetween can be applied.

  Here, the gate terminals of the thin film transistors Tr41 and Tr42 are provided with an output enable signal EN and a precharge for performing a series of control operations (luminance detection operations described later) for detecting the emission luminance of a specific display pixel (light emitting element). Each of the signals φpg is applied, and the top gate control signal φTG and the bottom are applied to the top gate electrode (top gate terminal) TG and the bottom gate electrode (bottom gate terminal) BG of the double gate type photosensor PW. The gate control signal φBG is applied to each. Each control signal will be described in the luminance detection operation described later.

  Thereby, a part of the light emitted by the light emitting operation of the specific display pixel (light emitting element) is extracted to the back side of the display panel 110A, propagates in the light guide plate 140, and is lateral to the light guide plate 140. The incident light is incident on the light receiving sensor unit 150 (the semiconductor layer 41 via the top gate electrode TG of the double gate type photosensor PW) provided so that the light receiving surface faces the end surface 140s as the back light LTb. The amount of carriers accumulated and accumulated in the semiconductor layer changes according to the amount of, and the drain voltage VD changes. At this time, the high-level output enable signal EN is applied in synchronization with the light emission operation of the specific display pixel, so that the thin film transistor Tr41 of the light receiving sensor unit 150 is turned on. Therefore, the drain voltage VD is used as detection data. , And output to the correction control circuit 160 (amplifier AMP) via the detection terminal TMf.

Next, the luminance detection operation (drive control method) of the double-gate photosensor PW having the above-described configuration will be described in detail.
As shown in FIG. 18, the luminance detection operation of the double gate type photosensor PW includes a reset period Trst, a charge accumulation period Ta, a precharge period Tprch, and a readout period Tread in a predetermined processing operation period (processing cycle). This is realized by setting an operation period.

  Specifically, first, in the reset period Trst, as shown in FIG. 18, a reset pulse (for example, + 15V) is applied to the top gate electrode (top gate terminal) TG of the double gate type photosensor PW as the top gate control signal φT. ) Is applied, and a reset operation (initialization operation) for releasing carriers (here, holes) accumulated in the semiconductor layer 41 is executed.

  Next, in the charge accumulation period Ta, by applying a low-level bias voltage (for example, −15 V) as the top gate control signal φT to the top gate electrode TG, the reset operation is completed, and the charge accumulation operation (charge The accumulation period Ta) is started. Here, in the charge accumulation period Ta, the back light LTb emitted from a specific display pixel, extracted to the back side of the display panel 110A, propagated through the light guide plate 140, and emitted from the side end face 140s is transparent. The light passes through the top gate electrode TG made of an electrode layer and enters the semiconductor layer 41. Thereby, electron-hole pairs are generated in the incident effective region (carrier generation region) of the semiconductor layer 41 in accordance with the amount of light incident on the semiconductor layer 41 during the charge accumulation period Ta, and the semiconductor layer 41 and the block insulating film 44 are generated. Holes are accumulated in the vicinity of the interface (around the channel region).

  In the precharge period Tprch set in parallel with the charge accumulation period Ta, the thin film transistor Tr42 is turned on by applying a high level precharge signal φpg, and a high level precharge pulse (precharge voltage) is applied. Vpg is applied to the drain electrode 43 of the double gate type photosensor PW to execute a precharge operation for holding charges.

  Next, in the read period Tread, after the precharge period Tprch has elapsed, a high level read pulse (for example, +10 V) is applied as the bottom gate control signal φB to the bottom gate electrode BG of the double gate type photosensor PW. Thus, a read operation is performed in which a drain voltage VD having a voltage value corresponding to carriers (holes) accumulated in the channel region during the charge accumulation period Ta is generated.

Here, the change tendency of the drain voltage VD shows a tendency that the drain voltage VD sharply decreases when there are many carriers accumulated in the charge accumulation period Ta (bright state), while there are few accumulated carriers. In such a case (dark state), it tends to decrease gradually. For example, by detecting the drain voltage VD (= Vrd) after the elapse of a predetermined time from the start of the read period Tread, the double gate type photosensor PW is detected. Detection data corresponding to the amount of incident light, that is, light emitted from a specific display pixel (light emitting element) constituting the display panel 110A (light emission luminance) is obtained.
In the detection data output period Tout, the thin film transistor Tr41 is turned on by applying a high level output enable signal EN, and the drain voltage VD (= Vrd) is corrected as detection data via the detection terminal TMf. Output to the control circuit 160.

Therefore, according to the display device including the light receiving sensor unit having such a configuration, the functional elements constituting the light receiving sensor unit can be simplified and thinned, and thus the configuration in which the photodiode described above is applied (see FIG. 9), the scale of the device can be reduced, and a small display device with good display quality can be realized.
Note that the light receiving sensor unit including the light receiving element shown in each of the above specific examples is only provided on a specific side end surface of the light guide plate, as shown in FIGS. 14 (a) and 14 (b). Alternatively, a thin film process is applied to form a sensor array in which a plurality of light receiving elements (photoconductive sensors and double gate type photosensors) are arranged one-dimensionally, as shown in FIG. A configuration may be applied in which each light receiving surface is disposed so as to be opposed to and in close contact with each of the side end surfaces or the plurality of side end surfaces.

<Other configuration examples of display device>
Next, another configuration example of the display device (display panel and its peripheral circuit) to which the above-described light guide plate and correction circuit unit according to the present invention can be applied will be described with reference to the drawings.
FIG. 19 is a schematic configuration diagram showing another configuration example of the display device according to the present invention, and FIG. 20 is a block diagram showing a main part of an example of a data driver applied to this configuration example. In addition, about the structure equivalent to embodiment mentioned above, the same code | symbol is attached | subjected and the description is simplified or abbreviate | omitted.

  In the above-described embodiment, the display device to which the light guide plate and the correction circuit unit according to the present invention are applied has a configuration including a display panel, a gate driver, and a data driver corresponding to the voltage designation method. Is a change (deterioration) in light emission characteristics (functional elements constituting the pixel driving circuit and element characteristics of the light emitting elements) depending on the external environment such as the ambient temperature and the usage time. In such a case, it is characterized by suppressing such deterioration of characteristics, and is not limited to the voltage designation method. In this configuration example, a case will be described in which a configuration (display panel, gate driver, and data driver) corresponding to the current designation method as shown in the above-described prior art is provided.

  As shown in FIG. 19, a display device 100B according to this configuration example includes a light guide plate 140, a light receiving sensor unit 150, a correction control circuit 160, a system controller (not shown), and a display that have the same configuration as the above-described embodiment. In addition to the signal generation circuit (not shown), the display panel 110B including a display pixel EMB (details will be described later) having a circuit configuration corresponding to the current designation method, and each display pixel EMB are set to a selected state. A gate driver 120B for supplying predetermined power supply voltages Vsc1, Vsc2,... (Hereinafter collectively referred to as “power supply voltage Vsc”) in a non-selected state of the display pixel EMB, and each display pixel set in the selected state Data for supplying gradation signal currents Idata1, Idata2,... (Hereinafter collectively referred to as “gradation signal current Idata”; gradation signals) according to display data to the EMB. And a driver 130B. Here, description of the light guide plate 140, the light receiving sensor unit 150, the correction control circuit 160, the system controller, and the display signal generation circuit having the same configuration as that of the above-described embodiment is omitted.

(Display panel 110B)
For example, as shown in FIG. 19, the display panel 110 </ b> B according to the present configuration example is arranged in parallel to the scanning lines SL in addition to the scanning lines SL and the data lines DL arranged so as to be orthogonal to each other. Power supply voltage supply lines VL1, VL2,... (Hereinafter collectively referred to as “power supply line VL”), and a current designation method in the vicinity of each intersection of the scan line SL, the power supply line VL, and the data line DL The pixel drive circuit (light emission drive circuit) DCB having a circuit configuration corresponding to the above and the display pixel EMB provided with the organic EL element (current control type light emitting element) OEL are connected.
Here, each display pixel EMB may be provided with the current designation type pixel driving circuit (see FIG. 22B) shown in the prior art, and the thin film transistor of the thin film transistor as compared with the conventional circuit configuration. A circuit configuration (for example, a pixel drive circuit DCB) that can reduce the number and can unify the channel polarity may be used.

  Specifically, in the pixel drive circuit DCB according to this configuration example, as shown in FIG. 19, the gate terminal is connected to the scanning line SL, the source terminal is connected to the power supply line VL, and the drain terminal is connected to the contact N51. A channel type thin film transistor (selection switch) Tr51, an n channel type thin film transistor (selection switch) Tr52 having a gate terminal connected to the scanning line SL, a source terminal and a drain terminal connected to the data line DL and a contact N52, and a gate terminal Is connected to the contact N51, the n-channel thin film transistor (light emission drive switch) Tr53 whose source terminal and drain terminal are connected to the power supply line VL and the contact N52, respectively, and the capacitor Cb connected between the contact N51 and the contact N52. The anode terminal of the organic EL element OEL is a contact N5. The cathode terminal are respectively connected to the ground potential (Vgnd). In the pixel driving circuit DCB shown in FIG. 19, Cb is a parasitic capacitance (holding capacitance) formed between the gate and source of the thin film transistor Tr53, or an auxiliary capacitance additionally formed between the gate and source. is there.

  In the display pixel EMB having such a configuration, the scanning signal Vscan applied from the gate driver 120 to the scanning line SL at a predetermined timing, and the power supply voltage applied to the power supply line VL in synchronization with the scanning signal Vscan. Based on Vsc, the gradation signal current Idata applied from the data driver 130 to the data line DL, the light emission drive current flowing through the organic EL element OEL is controlled by the pixel drive circuit DCB, and the light emission operation and the luminance gradation during light emission are controlled. Be controlled. The specific drive control operation and cross-sectional configuration of the display pixel EMB formed on the display panel 110 will be described in detail later.

(Gate driver 120B)
Similarly to the gate driver (see FIG. 2) shown in the above-described embodiment, the gate driver 120B scans each scanning line SL at a high level based on a scanning control signal supplied from a system controller (not shown). The signal Vscan is sequentially applied, and a power supply voltage Vsc that is an inverted signal of the scanning signal Vscan (having a signal level (low level) having an inverted polarity) is applied to each power supply line VL in synchronization with the scanning signal Vscan. As a result, the display pixel EM group for each row is set to a selected state, and a predetermined gradation signal current Idata applied via the data line DL by the data driver 130B is written to the pixel drive circuit DCB. Control.

  In addition, after the selection state, a low level scanning signal Vscan is applied to each scanning line SL, and a high level power supply voltage Vsc is applied to each power supply line VL in synchronism to thereby display pixels EM for each row. The group is set to a non-selected state, and the organic EL element OEL is controlled to emit light at a luminance gradation based on the gradation signal current Idata written to each pixel driving circuit DCB.

  Here, specifically, for example, as shown in FIG. 19, the gate driver 120B includes a plurality of stages of shift blocks SB ′ including a shift register and a buffer corresponding to each scanning line SL and power supply line VL. Based on a scan control signal (scan start signal SST, scan clock signal SCK, etc.) supplied from a system controller (not shown), the shift register sequentially generates shift signals from the top to the bottom of the display panel 110B. The shifted signal is converted to a predetermined voltage level (high level) through a buffer and output to each scanning line SL as a scanning signal Vscan, and an inverted signal of the scanning signal Vscan, the predetermined signal level being The power supply voltage Vsc is output to each power supply line VL.

  In this configuration example, as shown in FIG. 19, the scanning signal Vscan applied to the scanning line of each row and the power supply line are applied by the shift block SB ′ of each stage provided in the gate driver 120B. A configuration for generating and outputting a power supply voltage Vsc (that is, a configuration in which both a scanning signal generation function and a power supply voltage generation function are integrated) is shown, but the present invention is not limited to this. For example, a gate driver having only a function of generating and outputting a scanning signal Vscan at a position facing the display panel 110B (ie, corresponding to the gate driver 120A shown in the above-described embodiment), and a power supply voltage Vsc The power supply driver having only the function of generating and outputting the power may be provided individually.

(Data driver 130B)
The data driver 130B performs correction control from the display signal generation circuit based on a data control signal supplied from a system controller (not shown), for example, similarly to the data driver (see FIG. 2) shown in the above-described embodiment. The display data (corrected data) supplied via the circuit 160 is captured and held, an analog signal current corresponding to the display data is generated, and applied to each data line DL as a gradation signal current Idata.

  Here, as shown in FIG. 20, the data driver 130B has the same shift register circuit 131, data register circuit 132, data latch circuit 133, D / D as the data driver (see FIG. 3) shown in the above-described embodiment. In addition to the A converter 134, the gradation signal current Idata corresponding to the display data converted into the analog signal voltage by the D / A converter 134 is generated, and based on the output enable signal OE supplied from the system controller, A voltage-current conversion / current conversion circuit 136 that supplies the data line DL.

  By such a data driver 130B, the gradation signal current Idata corresponding to the corrected data of the display data composed of digital signals supplied from the display signal generation circuit via the correction control circuit 160 is generated, and a predetermined timing is generated. Are supplied to the data lines DL all at once or sequentially (when the gradation signal current Idata has a negative polarity, the gradation signal current Idata is drawn in the direction from the data line DL side to the data driver 130B side. Is controlled to flow).

Next, a display pixel portion applied to the display device according to this configuration example will be briefly described with reference to the drawings.
FIG. 21 is a configuration diagram showing a specific example (circuit layout and cross-sectional structure) of a display pixel portion applied to the display device according to this configuration example. About the structure equivalent to embodiment mentioned above, the same code | symbol is attached | subjected and the description is simplified or abbreviate | omitted.

  In the layout design process using CAD or the like, the display pixel EMB having an equivalent circuit as shown in FIG. 19 has, for example, scanning lines SL arranged in the row direction as shown in FIG. A pixel formation region is formed in a rectangular region surrounded by the power supply line VL arranged in parallel with the scan line SL and the data line DL arranged orthogonal to the scan line SL and the power supply line VL. A thin film transistor Tr51 to Tr53, a capacitor Cb, and an inter-element wiring portion that connects between the thin film transistors Tr51 to Tr53 are defined along substantially the outer edges (scanning line SL, data line DL, and power supply line VL) of the pixel formation region. Be placed.

  Further, the organic EL element OEL is formed on the insulating substrate 111 in the organic EL element formation area ARel excluding the formation areas such as the thin film transistors Tr51 to Tr53 and the inter-element wiring portion in the pixel formation area, as shown in FIG. As shown in FIG. 5B, the transparent anode electrode 112 connected to the drain electrodes of the thin film transistors Tr52 and Tr53 via the insulating film (the gate insulating films of the thin film transistors Tr51 to Tr53), as in the case shown in FIG. The organic EL layer 113 (a hole transport layer 113a and an electron transport light emitting layer 113b) and an opaque cathode electrode 114 are sequentially stacked.

Here, the thin film transistors Tr51 to Tr53, the inter-element wiring portion, and the like are formed at a boundary portion between the adjacent display pixels EMB and the organic EL element formation region ARel, and an organic EL element formation is formed on the upper layer thereof. A partition wall 116 that separates the areas ARel from each other is provided. In addition, an opening HLa is provided at an arbitrary position of the cathode electrode 114.
In FIG. 21A, HLa illustrated in the organic EL element formation region ARel indicates an example of an opening formed at an arbitrary position of the cathode electrode 114 (not illustrated), and EG3, ES3, ED3 represents a gate electrode, a source electrode, and a drain electrode of the thin film transistor Tr51. EG4, ES4, and ED4 represent a gate electrode, a source electrode, and a drain electrode of the thin film transistor Tr52, respectively. EG5, ES5, and ED5 represent a thin film transistor Tr53. The gate electrode, source electrode, and drain electrode are shown.

Next, a driving control method for a display pixel including the above-described pixel driving circuit will be briefly described.
In the drive control operation of the display panel 110B having the display pixels as shown in FIG. 19, first, the scanning signal Vscan of the selection level (high level) is applied from the gate driver 120B to the scanning line SL in the writing operation period. And a low-level power supply voltage Vsc having an inverted polarity is applied to the power supply line VL in synchronization with the scanning signal. In synchronism with this timing, the data driver 130B corresponds to display data (corrected data) or luminance detection data in the same manner as the image display operation or the specific amount detection operation described in the above embodiment. A gradation signal current Idata is generated and supplied to the data line DL. Here, a negative current is supplied as the gradation signal current Idata, and the current is drawn in the direction of the data driver 130B from the display pixel EMB (pixel drive circuit DCB) via the data line DL. Shall. As a result, the thin film transistors Tr51 and Tr52 constituting the pixel drive circuit DCB are turned on, the low level power supply voltage Vsc is applied to the contact N51, and the grayscale signal current Idata is pulled in via the thin film transistor Tr52. A voltage level lower than the level power supply voltage Vsc is applied to the contact N52.

As described above, the potential difference is generated between the contacts N51 and N52 (between the gate and the source of the thin film transistor Tr53), so that the thin film transistor Tr53 is turned on. A write current corresponding to the gradation signal current Idata flows in the line DL direction.
At this time, the capacitor Cb accumulates charges corresponding to the potential difference generated between the contacts N51 and N52 and holds (charges) as a voltage component. At this time, the potential applied to the anode terminal (contact N52) of the organic EL element OEL is lower than the potential of the cathode terminal (ground potential), and a reverse bias voltage is applied to the organic EL element OEL. Therefore, no light emission drive current flows through the organic EL element OEL, and no light emission operation is performed.

Next, in the light emission operation period, the gate driver 120B applies the non-selection level (low level) scanning signal Vscan to the scanning line SL and also applies the high level power supply voltage Vsc to the power supply line VL. To do. Further, in synchronization with this timing, the gradation signal current Idata drawing operation is stopped.
Thereby, the thin film transistors Tr51 and Tr52 are turned off, the application of the power supply voltage Vsc to the contact N51 is cut off, and the application of the voltage level due to the drawing operation of the gradation signal current Idata to the contact N52 is cut off. Therefore, capacitor Cb holds the charge accumulated in the above-described write operation.

  As described above, the capacitor Cb holds the charge (charge voltage) accumulated during the writing operation, whereby the potential difference between the contacts N51 and N52 (between the gate and the source of the thin film transistor Tr53) is held. Tr53 is kept on. Further, since the power supply voltage Vsc having a voltage level higher than the ground potential is applied to the power supply line VL, light emission is driven from the power supply line VL to the organic EL element OEL through the thin film transistor Tr53 and the contact N52 in the forward bias direction. A current flows and a light emitting operation is performed.

Here, the charging voltage held in the capacitor Cb corresponds to a potential difference when a writing current corresponding to the gradation signal current Idata is supplied to the thin film transistor Tr53 during the writing operation, and thus the light emission flowing through the organic EL element OEL. The drive current has a current value equivalent to the write current, and in the light emission operation period, the organic EL element OEL is based on the voltage component corresponding to the gradation signal current written in the write operation period. Continues the operation of emitting light at a desired luminance gradation.
Then, such a series of drive control operations are sequentially repeated for all the display pixels EMB of the display panel 110B, thereby performing the image display operation or the specific amount detection operation as described in the above-described embodiment. Is executed.

  Therefore, even in a display device including a display panel (display pixel) corresponding to a current designation type driving method as shown in this configuration example and its peripheral circuit, display is performed at an arbitrary timing prior to a normal image display operation. After performing a specific amount detection operation for obtaining detected gradation data by causing each display pixel (light emitting element) constituting the panel to perform a light emission operation based on luminance detection data, in the normal image display operation, the specific amount described above is used. The display data supplied from the display signal generation circuit is corrected and supplied to the data driver based on the correction value generated by comparing the detected gradation data and the initial gradation data for each pixel acquired by the detection operation. Therefore, the relationship of the light emission luminance of the light emitting element (organic EL element) to the luminance gradation specified by the display data is always maintained in a state that approximates the initial state. Bets can be, deterioration or fluctuation of the emission characteristics in each display pixel (light emitting element) is corrected, the image information can be displayed with good and stable quality over a long period.

  In this configuration example, a configuration in which the pixel drive circuit DCB including n-channel thin film transistors Tr51 to Tr53 is provided as the display pixel EMB configuring the display panel is shown. According to such a circuit configuration, since only a n-channel type thin film transistor is applied, a thin film transistor with stable operating characteristics can be obtained using an amorphous silicon semiconductor manufacturing technology that has already been established. A pixel driving circuit that can be manufactured at low cost and suppresses variation in light emission characteristics of display pixels can be realized.

  Further, in this configuration example, the current designation type pixel driving circuit including three thin film transistors is shown as the display pixel constituting the display panel, but the display device according to the present invention is not limited to this, and at least In each display pixel, if the current value of the light emission driving current is set based on the gradation signal current and the current control type light emitting element is driven and controlled with the luminance gradation corresponding to the current value, other circuits are used. It may have a configuration.

1 is a block diagram illustrating an embodiment of an overall configuration of a display device according to the present invention. It is a schematic block diagram which shows the principal part structural example of the display apparatus which concerns on this embodiment. It is a block diagram which shows the principal part structural example of the data driver applied to the display apparatus which concerns on this embodiment. It is a schematic block diagram which shows the relationship between the display panel (display pixel) applied to the display apparatus which concerns on this embodiment, a light-guide plate, and a light-receiving sensor part. It is a block diagram which shows the specific example (circuit layout and cross-sectional structure) of the display pixel part applied to the display apparatus which concerns on this embodiment. It is a cross-sectional block diagram which shows an example of the manufacturing method of the display pixel part applied to the display apparatus which concerns on this embodiment. It is a schematic sectional drawing which shows the specific structural example of a display pixel part for improving the extraction efficiency of the emitted light which concerns on this embodiment. It is a schematic block diagram which shows the specific structural example of the light-guide plate for improving the extraction efficiency of the emitted light which concerns on this embodiment. It is a circuit diagram which shows one specific example of the light reception sensor part applied to the display apparatus which concerns on this embodiment. It is a timing chart which shows an example of specific quantity detection operation applied to the drive control method of a display concerning this embodiment. It is a flowchart which shows an example of the drive control operation | movement concerning the specific amount detection operation | movement which concerns on this embodiment. 6 is a timing chart illustrating an example of an image display operation applied to the display device drive control method according to the embodiment. It is a block diagram which shows the other structural example (circuit layout and cross-sectional structure) of the display pixel part applied to the display apparatus which concerns on this invention. It is a schematic perspective view which shows the other relationship between the display panel applied to the display apparatus which concerns on this invention, and a light-receiving sensor part. It is a schematic perspective view which shows the other relationship between the display panel applied to the display apparatus which concerns on this invention, a light-guide plate, and a light-receiving sensor part. It is the cross-sectional block diagram of the light receiving element which shows the other specific example of the light receiving sensor part applied to the display apparatus which concerns on this invention, and the circuit diagram of a light receiving sensor part. It is the cross-sectional block diagram of the light receiving element which shows the other specific example of the light receiving sensor part applied to the display apparatus which concerns on this invention, and the circuit diagram of a light receiving sensor part. It is a timing chart which shows the basic drive control method of the light receiving sensor part (light receiving element) in this example. It is a schematic block diagram which shows the other structural example of the display apparatus which concerns on this invention. It is a block diagram which shows the principal part of the data driver applied to this structural example. It is a block diagram which shows the specific example (circuit layout and cross-sectional structure) of the display pixel part applied to the display apparatus which concerns on this structural example. It is an equivalent circuit diagram which shows the principal part structural example of each display pixel of the light emitting element type display provided with the organic EL element in a prior art.

Explanation of symbols

100A, 100B Display device 110A, 110B Display panel 120A, 120B Gate driver 130A, 130B Data driver 140 Light guide plate 150 Light receiving sensor unit 160 Correction control circuit 170 System controller EMA, EMB Display pixel DCA, DCB Pixel drive circuit OEL Organic EL element ADC A / D converter BM storage unit CMR comparison correction unit

Claims (21)

A display panel in which a plurality of display pixels are two-dimensionally arranged on a transparent insulating substrate is selected for each row, and a grayscale signal corresponding to display data is applied, whereby the display pixels are In a display device that displays a desired image information on a display surface side of the display panel by performing a light emission operation at a luminance gradation according to display data.
The display device includes: a light guide plate disposed on a back side of the display panel; and a correction circuit unit that corrects the gradation signal applied to each of the display pixels according to a light emission characteristic of the display pixel. Have
The correction circuit unit includes:
A specific amount detection means for detecting a specific amount according to the light emission characteristics of the display pixel when a light receiving surface is provided opposite to at least one side end surface of the light guide plate and a specific gradation signal is applied; ,
Storage means for holding detected gradation data based on at least the detected specific amount;
Based on a comparison result between the detected gradation data held in the storage means and initial gradation data based on the initial value of the specific amount corresponding to the specific gradation signal in the display pixel, the display data And a signal correction means for generating a correction signal for correcting the gradation signal applied to the display pixel so that the relationship between the specific amount and the specific amount approaches the relationship in the initial state of the display pixel;
A display device comprising: The display panel includes a plurality of scan lines arranged in a row direction on the insulating substrate and a plurality of data lines arranged in a column direction, and the plurality of display pixels. Are arranged in the vicinity of each intersection of a plurality of scanning lines and a plurality of data lines,
The display device sequentially applies a scanning signal to the display pixels for each row of the display panel at a predetermined timing, and generates a gradation signal corresponding to the display data, and a scanning drive circuit that sets the selected state. The display device according to claim 1, further comprising: a signal driving circuit that applies to the display pixels in the row set in the selected state. The specific amount detection means includes at least a light receiving element that measures luminance corresponding to light emission luminance in the display pixel when the specific gradation signal is applied to the display pixel.
The light receiving element detects a part of light extracted toward the light guide plate among light emitted from the display pixel when the specific gradation signal is applied to each display pixel. The display device according to claim 1 or 2. The display device according to claim 1, wherein at least one of the specific amount detection means is provided in close contact with only one side end surface of the light guide plate. The display device according to claim 1, wherein at least one of the specific amount detection means is provided in close contact with each of a plurality of different side end surfaces of the light guide plate. The display device condenses the light extracted from the display pixels to the light guide plate among the display pixels and the light guide plate, and guides the light to the light guide plate. The display device according to claim 1, further comprising a light collecting unit. The light guide plate includes light guide means that guides light extracted from the display pixel to the light guide plate side in a direction in which the specific amount detection means is installed. The display device according to claim 1. The display device according to claim 1, wherein the storage unit stores the initial gradation data in addition to the detected gradation data. The detection of the specific amount by the specific amount detection means is performed at least at a timing when the power to the display panel is turned on and after a predetermined time or more after the power is turned on to the display panel. The display device according to claim 1, wherein: The display data comprises digital data,
10. The correction circuit unit includes signal conversion means for converting the specific signal level output from the light receiving element into digital data and generating at least the detected gradation data. The display apparatus in any one. The display device according to claim 3, wherein the light receiving element is a photodiode. The display device according to claim 3, wherein the light receiving element is a photoconductive sensor. The display device according to claim 3, wherein the light receiving element is a photosensor having a double gate type transistor structure. The display pixel is at least
A selection switch for taking in the gradation signal applied from the signal driving circuit by the scanning signal applied from the scanning driving circuit; and a light emission driving switch for supplying a driving current having a current value corresponding to the gradation signal; A light-emission driving circuit having a storage capacitor for storing a voltage component corresponding to the gradation signal,
A current-controlled light-emitting element that emits light at a luminance gradation corresponding to the current value of the drive current;
The display device according to claim 1, further comprising: The light emitting element is an organic electroluminescent element,
Among the pair of electrodes that constitute the organic electroluminescent element and supply the driving current for a predetermined light emitting operation, the organic electroluminescent element is disposed at an arbitrary position of the electrode on the light guide plate side. The display device according to claim 14, wherein an opening is provided for extracting a part of light emitted from the cent element to the light guide plate side. A display panel in which a plurality of display pixels are two-dimensionally arranged on a transparent insulating substrate is selected for each row, and a grayscale signal corresponding to display data is applied, whereby the display pixels are In a drive control method of a display device that performs a light emission operation at a luminance gradation according to display data and displays desired image information on the display surface side of the display panel.
Applying a specific gradation signal to the display pixel;
Detecting a specific amount according to the light emission characteristics of the display pixel by a light receiving element provided with a light receiving surface facing at least one side end surface of a light guide plate disposed on the back side of the display panel;
Holding detected gradation data based on the detected specific amount;
Based on the comparison result between the held detected gradation data and the initial gradation data based on the initial value of the specific amount corresponding to the specific gradation signal in the display pixel, the display data and the specific amount Correcting the gradation signal applied to the display pixels so that the relationship between
A drive control method for a display device, comprising: The step of detecting the specific amount propagates through the light guide plate after being extracted to the light guide plate side of the light emitted in a state where a specific gradation signal is applied to the display pixel. The drive control method for a display device according to claim 16, wherein a part of light emitted from the side end face is detected by the light receiving element. The step of detecting the specific amount is performed at least at a timing when the power to the display panel is turned on and after a predetermined time or more after the power is turned on to the display panel. Item 18. A drive control method for a display device according to Item 16 or 17. 19. The display device drive according to claim 16, wherein the specific gradation signal is set to a signal level for causing the display pixel to emit light at a maximum luminance gradation. Control method. 19. The display device according to claim 16, wherein the specific gradation signal is set to a signal level for causing the display pixel to perform a light emission operation at a plurality of different luminance gradations. Drive control method. The display pixel passes a driving current having a current value corresponding to the gradation signal, and accumulates a voltage component corresponding to the gradation signal, and a luminance scale corresponding to the current value of the driving current. A current-controlled light-emitting element that emits light with a tone,
The step of detecting the specific amount measures a luminance corresponding to the light emission luminance of the light emitting element when the specific gradation signal is applied to the light emission driving circuit provided in each of the display pixels. 21. The display device drive control method according to claim 16, wherein the display device drive control method is performed.

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