JP5240534B2 - Display device and drive control method thereof - Google Patents

Display device and drive control method thereof Download PDF

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JP5240534B2
JP5240534B2 JP2005122061A JP2005122061A JP5240534B2 JP 5240534 B2 JP5240534 B2 JP 5240534B2 JP 2005122061 A JP2005122061 A JP 2005122061A JP 2005122061 A JP2005122061 A JP 2005122061A JP 5240534 B2 JP5240534 B2 JP 5240534B2
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display
gradation
data
light emission
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JP2006301250A (en
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友之 白嵜
潤 小倉
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カシオ計算機株式会社
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The present invention relates to a display device and a drive control method thereof, and more particularly, a plurality of current control type (or current drive type) light emitting elements that emit light at a predetermined luminance gradation by supplying a current according to display data. The present invention relates to a display device including an arrayed display panel (display pixel array) and a drive control method for the display device.

  In recent years, display devices that are light and thin and have low power consumption have been widely used as monitors and displays for personal computers and video equipment. In particular, a liquid crystal display device (LCD) is widely applied as a display device for portable devices (mobile devices) such as mobile phones, digital cameras, personal digital assistants (PDAs), and electronic dictionaries that have been popular in recent years.

  As a next-generation display device following such a liquid crystal display device, an organic electroluminescence element (organic EL element), an inorganic electroluminescence element (inorganic EL element), or a light emitting element such as a light emitting diode (LED) (self Research and development for full-scale popularization of light-emitting element type display devices (light-emitting element type displays) having a display panel in which light-emitting optical elements) are arranged in a matrix are actively performed.

  In particular, a light-emitting element type display using an active matrix driving method has a higher display response speed than the above-described liquid crystal display device, and has no viewing angle dependency, and has high luminance and high contrast, and display image quality. A feature that is extremely advantageous for application to portable devices that enables high definition, etc., and does not require a backlight like a liquid crystal display device, and can be further reduced in thickness and weight and power consumption. have.

  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, Patent Document 1 discloses a drive circuit (light emission drive circuit) including a plurality of switching elements for controlling light emission of the light emitting elements in addition to the light emitting elements, for each display pixel constituting the display panel. A configuration with is described.

Hereinafter, a display pixel having a light emission driving circuit in the prior art will be briefly described.
FIG. 35 is a schematic configuration diagram showing a main part of a light emitting element type display according to the prior art, and FIG. 36 is a main part of a display pixel (light emission drive circuit and light emitting element) applicable to the light emitting element type display according to the prior art. It is an equivalent circuit diagram showing a configuration example.

  As shown in FIG. 35, an active matrix light-emitting element type display (organic EL display device) according to the prior art is roughly composed of a plurality of scanning lines (selection lines) SLp and data lines (data lines) arranged in the row and column directions. Signal line) In the vicinity of each intersection of DLp, a display panel 110P in which a plurality of display pixels EMp are arranged in a matrix, a scanning driver (scanning line driving circuit) 120P connected to each scanning line SLp, and each data line DLp And a data driver (data line driving circuit) 130P connected to each other, and the data driver 130P generates a gradation signal (a gradation current Ipix, which will be described later) corresponding to the display data, via each data line DLp. Each display pixel EMp is configured to be supplied.

  Here, as shown in FIG. 36, the display pixel EMp described in Patent Document 1 or the like is near each intersection of the pair of scanning lines SLp1 and SLp2 and the data line DLp arranged in parallel to each other. A thin film transistor Tr111 having a gate terminal connected to the scanning line SLp1, a source terminal and a drain terminal connected to the data line DLp and the contact N111, a gate terminal connected to the scanning line SLp2, and a source terminal and a drain terminal connected to the contact N111 and a contact N122, respectively. The connected thin film transistor Tr112, the gate terminal connected to the contact N112, the drain terminal connected to the contact N111, the thin film transistor Tr113 applied with the high power supply voltage Vdd to the source terminal, the gate terminal connected to the contact N112, the source terminal Thin film transistor with high power supply voltage Vdd applied to And a light emitting drive circuit DP1 having a transistor Tr114, and an organic EL element OEL having an anode terminal connected to the drain terminal of the thin film transistor Tr114 of the floor light emission drive circuit DP1 and a ground potential applied to the cathode terminal. Has been.

  Here, in FIG. 36, the thin film transistor Tr111 is composed of an n-channel field effect transistor, and the thin film transistors Tr112 to Tr114 are composed of p-channel field effect transistors. CP1 is a parasitic capacitance formed between the gate and source of the thin film transistors Tr113 and Tr114.

  In the light emission driving circuit DP1 having such a configuration, the four transistors (switching means) including the thin film transistors Tr111 to Tr114 are controlled to be turned on and off at a predetermined timing. The element OEL is controlled to emit light.

  That is, in the light emission drive circuit DP1, when the scanning driver 120P applies the high level scanning signal Vsel1 to the scanning line SLp1 and the low level scanning signal Vsel2 to the scanning line SLp2, respectively, the display pixel is set in the selected state. Tr111, Tr112, and Tr113 are turned on, and the gradation current Ipix corresponding to the display data supplied to the data line DLp by the data driver 130P flows through the thin film transistors Tr111 and Tr113. At this time, since the gate and drain of Tr113 are electrically short-circuited by Tr112, Tr113 operates in the saturation region. As a result, the current level of the gradation current Ipix is converted to a voltage level by the thin film transistor Tr113, and a predetermined voltage is generated between the gate and the source (writing operation). The thin film transistor Tr114 is turned on according to the voltage generated between the gate and source of the thin film transistor Tr113, and a predetermined light emission drive current flows from the high power supply voltage Vdd to the ground potential via the thin film transistor Tr114 and the organic EL element OEL. The EL element OEL emits light (light emission operation).

  Next, for example, when a high level scanning signal Vsel2 is applied to the scanning line SLp2, the thin film transistor Tr112 is turned off, whereby the voltage generated between the gate and the source of the thin film transistor Tr113 is held by the parasitic capacitance CP1, and then the scanning is performed. When the low level scanning signal Vsel1 is applied to the line SLp1, the thin film transistor Tr111 is turned off, thereby electrically disconnecting the data line DLp and the light emission drive circuit DP1. Thereby, the thin film transistor Tr114 is continuously turned on by the potential difference based on the voltage held in the parasitic capacitance CP1, and a predetermined light emission drive current is supplied from the high power supply voltage Vdd to the ground potential via the thin film transistor Tr114 and the organic EL element OEL. The organic EL element OEL continues to emit light.

  Here, the light emission drive current supplied to the organic EL element OEL via the thin film transistor Tr114 is controlled to have a current value based on the luminance gradation of the display data, and this light emission operation is performed according to the next display data. Until the gradation current is written to each display pixel, for example, control is performed so as to continue for one frame period.

  The drive control method in the light emission drive circuit DP1 having such a circuit configuration supplies a gradation current Ipix that specifies a current value corresponding to display data to each display pixel EMp (between the source and drain of the thin film transistor Tr113). Based on the voltage held according to the current value, 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. This is called a gradation application method.

JP 2001-147659 A (pages 7 to 8, FIG. 1)

However, the light emission drive circuit adopting the current gradation designating method as described above has the following problems.
(1) That is, when a gradation current corresponding to display data having the lowest or relatively low luminance is written to each display pixel (at the time of low gradation display), a signal having a small current value corresponding to the luminance gradation of the display data It is necessary to supply current to each display pixel.

  Here, the operation of writing display data (gradation current) to each display pixel is equivalent to charging a capacitance component parasitic in the data line (a wiring capacitor and a storage capacitor constituting the display pixel) to a predetermined voltage. For example, when the wiring length of the data line is increased due to an increase in the size of the display panel and the number of display pixels connected to the data line is increased, the current value of the gradation current becomes smaller (that is, the lower order). The data line charging time becomes longer and the writing operation to the display pixel takes a long time, and the display written to the display pixel at a preset (specified) writing time. Insufficient writing occurs, in which data does not reach a sufficiently stable state (saturated state). As a result, a display pixel that cannot emit light with an appropriate luminance gradation according to display data is generated, and there is a problem in that a luminance difference occurs in the display panel, resulting in deterioration of display image quality.

(2) Further, in order to increase the definition of the display panel, the number of scanning lines arranged on the display panel is increased and the selection period (ie, writing time) of each scanning line is set short. However, as the current value of the gradation current becomes smaller, the sufficient writing operation to each display pixel will not be performed, resulting in insufficient writing, resulting in deterioration of display image quality, and high definition of the display panel is restricted. Had the problem of being.

(3) In addition to the circuit configuration described above, various types of light emission drive circuits employing the current gradation designation method are known. For example, all the switching elements constituting the light emission drive circuit are connected to a single light emission drive circuit. When a channel type thin film transistor is used, an amorphous silicon thin film transistor with a simple manufacturing process and uniform operating characteristics (electron mobility) can be applied. However, an amorphous silicon thin film transistor generally has a threshold voltage based on a driving history. It is known that the fluctuation (Vth shift) of the above occurs remarkably.

  As a result, the current value of the light emission drive current supplied to the light emitting element does not correspond to the display data due to the fluctuation of the threshold voltage of the light emitting driving switching element, and the light emission operation can be performed with an appropriate luminance gradation. Disappear. This variation in threshold voltage is due to the light emission history (thin film transistor drive history) of each display pixel (light emitting element), so that the light emission characteristics vary from display pixel to display pixel and display image quality deteriorates. It had the problem of inviting.

The present invention has been made in view of the problems described above, by supplying the light emission drive current having an appropriate current value corresponding to display data, a light emitting device was driven to emit light at appropriate luminance gradation corresponding to display data An object of the present invention is to provide a display device with good and uniform display image quality and a drive control method thereof.

According to the first aspect of the present invention, a current control type light emitting element and a light emitting driving element for supplying a light emitting driving current to the light emitting element at each intersection of a plurality of selection lines and data lines arranged in a row direction and a column direction. In a display device having a display panel in which each of a plurality of display pixels is arranged, a selection signal is sent to each display pixel in each row of the display panel through the selection line at a predetermined timing. A selection driving unit that sequentially applies and sets each display pixel of each row to a selected state for each predetermined selection period, and a gradation signal corresponding to the luminance gradation of display data for displaying desired image information A data driving unit that generates and supplies the display pixels in the row set in the selected state, and a first voltage and non-light emitting operation for setting the display pixels in the light emitting operation state in the plurality of display pixels. Any of the second voltages to set the state A power supply drive unit that applies as a supply voltage, and the data drive unit includes at least a threshold voltage detection unit that individually detects a threshold voltage specific to the light emission drive element of each display pixel; Storage means for storing threshold data corresponding to the threshold voltage detected by the threshold voltage detection means for each display pixel; and the threshold value stored in the storage means Compensation voltage generating means for generating a compensation voltage for compensating the threshold voltage of the light emitting drive element of each display pixel based on the data, and a predetermined for causing the light emitting element to emit light at a predetermined luminance gradation And a voltage component based on the gradation voltage and the compensation voltage as the gradation signal via the data lines. Set to Gradation signal generating means for individually supplying each display pixel in a row, and the power supply driver supplies the selection period to each display pixel in the row to which the gradation signal is supplied. In addition, the second voltage is applied as the supply voltage for a period longer than the selection period, and the display pixels in the row are set in the non-light emitting operation state for a period longer than the selection period. The plurality of display pixels arranged in the display panel are divided into a plurality of groups for each of a plurality of rows, and any one of the display pixels included in each group is assigned to each display pixel in each group. Over the period set in the selected state, the second voltage is commonly applied to the display pixels in the group, and the display pixels included in the group are set in the non-light emitting operation state. And included in the group The first voltage is commonly applied to the display pixels in the group during a period when the display pixels are not set in the selection period, and the display pixels included in the group are in the light emitting operation state. It is characterized by setting to.

According to a second aspect of the invention, in the display device according to claim 1, wherein the data driver, the voltage for the detection threshold of the higher potential than the threshold voltage to the light emission drive element of the display pixel And further comprising a detection voltage applying means for individually applying the threshold voltage detecting means, wherein the threshold voltage detecting voltage is applied to the light emitting drive element, and the threshold voltage detecting voltage is applied. A voltage after a part of the charge corresponding to is discharged and converged is individually detected as a threshold voltage of the light emitting drive element.

According to a third aspect of the present invention, in the display device according to the second aspect , the light emission drive element provided in each of the display pixels includes a current path through which the light emission drive current flows and the light emission drive current of the light emission element. A control terminal for controlling a supply state, wherein the detection voltage applying means applies the threshold detection voltage between the control terminal of the light emitting drive element and one end of the current path; The threshold voltage detection means detects, as the threshold voltage, a potential difference between the control terminal of the light emission drive element and one end side of the current path when no current flows in the current path. It is characterized by that.

According to a fourth aspect of the present invention, in the display device according to the second or third aspect , the threshold voltage detecting means converts the threshold voltage of the light emitting drive element detected as an analog signal into a digital signal. Means for generating the threshold data,
The compensation voltage generating means generates the compensation voltage composed of an analog signal for compensating the threshold voltage of the light emitting drive element based on the threshold data stored as a digital signal in the storage means. It is characterized by having.

According to a fifth aspect of the present invention, in the display device according to any one of the second to fourth aspects, the gradation voltage generating means is configured to provide the gradation voltage when the luminance gradation of the display data is the lowest gradation. And a means for generating a non-light-emitting display voltage having a predetermined voltage value for causing the light-emitting element to perform a non-light-emitting operation.
According to a sixth aspect of the present invention, in the display device according to any one of the second to fifth aspects, the data driving unit includes the threshold value corresponding to the threshold voltage detected from each of the display pixels. Threshold acquisition means for individually capturing and sequentially transferring data, and data acquisition for sequentially capturing and holding brightness gradation data for generating the gradation voltage for each of the display pixels. And means for individually storing the threshold value data for each of the plurality of display pixels transferred from the threshold value acquisition unit in correspondence with each of the plurality of display pixels. And the gradation voltage generation means generates the gradation voltage corresponding to the luminance gradation data for each of the plurality of display pixels held in the data acquisition means, and the gradation signal generation means In the selected state For the display pixels of the constant row, and supplying individually the gradation signal consisting of the voltage component based on the gradation voltage and said compensation voltage.

According to a seventh aspect of the present invention, in the display device according to the sixth aspect , the data acquisition unit and the threshold value acquisition unit sequentially capture the luminance gradation data individually, and the threshold data individually. And the configuration for sequentially transferring the data to each other is shared.

The invention according to claim 8 is the display device according to any one of claims 2 to 7 , wherein the data driver detects at least the threshold voltage of the display pixel by the threshold voltage detection means. A signal path for supplying the gradation signal to the display pixel by the gradation signal generation means, and a single data line provided corresponding to the display pixel are selectively connected. And a signal path switching means for performing switching control.

According to a ninth aspect of the present invention, in the display device according to the eighth aspect , the data driver further includes a signal path for applying the threshold detection voltage to the display pixel by the detection voltage applying unit. The single data line is configured to be selectively connected to the single data line.

According to a tenth aspect of the present invention, in the display device according to any one of the second to ninth aspects, the display device supplies a timing control signal, so that at least the selection driving unit, the data driving unit, and the power source are provided. A drive control unit that causes each of the drive units to operate at a predetermined timing is further provided, and the drive control unit applies all of the display pixels arranged in the display panel by the selection drive unit and the data drive unit. The gradation signal corresponding to the display data is individually supplied, and the light emitting element provided in each of the display pixels is operated to emit light at a predetermined timing with a luminance gradation corresponding to the display data. And means for generating the timing control signal for detecting a threshold voltage specific to the light emission drive element in a specific row of the display panel. To.

According to an eleventh aspect of the present invention, in the display device according to the tenth aspect , the drive control unit is configured to drive the light emission for the display pixels in different rows for each operation period by the selection driving unit and the data driving unit. It has means for generating the timing control signal for detecting a threshold voltage specific to the element.

According to a twelfth aspect of the present invention, in the display device according to the tenth aspect , the drive control unit is configured to emit the light for the display pixels in adjacent rows for each operation period by the selection drive unit and the data drive unit. It has means for generating the timing control signal for sequentially repeating the operation of detecting the threshold voltage specific to the drive element.

According to a thirteenth aspect of the present invention, in the display device according to any one of the second to twelfth aspects, each of the display pixels includes a light emission driving circuit that controls a light emission operation of the light emitting element. at least a first current path and a first control terminal, wherein the supply voltage to one end of the first current path is applied, the connection between the light emitting element to the other end of the first current path A transistor element connected to a contact; a second current path; and a second control terminal, wherein the second control terminal is connected to the selection line, and the supply voltage is connected to one end of the second current path. There is applied, has a said first switch means of the first control terminal of said transistor element to the other end of the second current path is connected, a third current path of the third control terminal of It said third control terminal is connected to the selection line, one end of the third current path Wherein the data lines are connected, said second switch means a third the connection contact to the other end of the current path of which is connected, wherein the light emission drive device is the transistor device, the detection voltage The applying means applies the threshold detection voltage between the first control terminal of the transistor element and the connection contact, and the threshold voltage detecting means is configured to apply the threshold voltage detecting means to the transistor element . A potential between one control terminal and the connection contact is detected as the threshold voltage, and the gradation signal generating means is connected between the first control terminal of the transistor element and the connection contact. A voltage component based on the gradation voltage and the compensation voltage is applied as the gradation signal.

A fourteenth aspect of the present invention is the display device according to any one of the first to thirteenth aspects, wherein the light emitting element is an organic electroluminescence element.

The invention according to claim 15 is a current-controlled light-emitting element and a light-emitting drive element that supplies a light-emission driving current to each intersection of a plurality of selection lines and data lines arranged in a row direction and a column direction. And a display panel in which each of the plurality of display pixels is arranged, and a selection signal is sequentially applied to the display pixels in each row of the display panel via the selection lines at a predetermined timing. In synchronization with the timing of setting each display pixel to the selected state for each predetermined selection period, the level corresponding to the luminance gradation of the display data for displaying desired image information via each data line is set. By supplying a tone signal to each display pixel in the row set to the selected state, each display pixel is caused to emit light at a predetermined luminance gradation, and the desired image information is displayed on the display panel. Each of the plurality of display pixels In a drive control method for a display device in which one of a first voltage that sets a display pixel in a light emitting operation state and a second voltage that sets a display pixel in a non-light emitting operation state is applied as a supply voltage, at least the plurality of display pixels A light emission driving element provided in each of the light emission driving elements that supplies a light emission driving current having a predetermined current value to the light emitting element based on the gradation signal has a potential higher than a threshold voltage unique to the light emission driving element. A detection voltage applying step for individually applying a threshold detection voltage, and a voltage after a portion of the charge corresponding to the threshold voltage detection voltage is discharged and converged, Threshold voltage detection step for detecting individually as the threshold voltage and storing the threshold voltage corresponding to the threshold voltage in the storage means for each display pixel; and the threshold voltage detection step stored in the storage means A compensation voltage generating step for individually generating a compensation voltage for compensating the threshold voltage of the light emission drive element for each display pixel based on the threshold value data; and A gradation voltage generation step for individually generating gradation voltages having a predetermined voltage value for light emission operation at a luminance gradation; and the gradation signal comprising voltage components based on the gradation voltage and the compensation voltage. And individually supplying each display pixel of the row set to the selected state via each data line, and holding the voltage component based on the gradation signal in the light emission driving element of each display pixel. A data writing step; and supplying the light emission drive current generated based on the voltage component held in the light emission drive element of each display pixel to each of the light emission elements, thereby setting the light emission element to a predetermined value. A gradation light emission step for performing light emission operation at the luminance gradation, and the display pixels of the row to which the gradation signal is supplied include the selection period and the supply voltage as the supply voltage over a period longer than the selection period. and applying a second voltage, seen containing a non-light emitting operation step of setting the non-light emitting operation state over the respective display pixels in the row in a period longer than the selection period, the said non-light emitting operation step Further, the plurality of display pixels arranged in the display panel are divided into a plurality of groups for each of a plurality of rows, and for each display pixel of each group, any one of the display pixels included in the group. Over the period set in the selected state, the second voltage is commonly applied to the display pixels of the group, and the display pixels included in the group are put into the non-light emitting operation state. Set, In a period when each display pixel included in the group is not set as the selection period, the first voltage is commonly applied to each display pixel of the group, and each display pixel included in the group the step of setting the light emission operation state characterized by containing Mukoto.

According to a sixteenth aspect of the present invention, in the display device drive control method according to the fifteenth aspect , the detection voltage application step and the threshold voltage detection step include at least all the displays arranged in the display panel. A specific row of the display panel is supplied during a certain operation period in which the gradation signals are individually supplied to the pixels and the display pixels emit light at a luminance gradation corresponding to the display data at a predetermined timing. This display pixel is executed for the display pixels.

According to a seventeenth aspect of the present invention, in the display device drive control method according to the sixteenth aspect , the detection voltage application step and the threshold voltage detection step are performed in the display pixels in different rows for each predetermined operation period. It is performed about.

According to an eighteenth aspect of the present invention, in the drive control method for a display device according to the sixteenth aspect , the detection voltage applying step and the threshold voltage detection step include the display of adjacent rows for each predetermined operation period. It is characterized in that it is sequentially executed for pixels.

According to a nineteenth aspect of the present invention, in the display device drive control method according to any one of the fifteenth to eighteenth aspects, the data writing step has a predetermined value when the luminance gradation of the display data is the lowest gradation. By generating the gradation signal including a non-light emitting display voltage having a voltage value and supplying it to the display pixel, the light emission driving element of the display pixel holds at least the voltage component equal to or lower than the threshold voltage. It is characterized by making it.

According to the display device and the drive control method thereof according to the present invention , all the display pixels arranged in the display panel are inherent to the light emission driving switching element (thin film transistor) provided in the display pixel (light emission drive circuit). , The threshold voltage of the switching element (threshold data) detected in advance for each display pixel at the time of writing the display data to each display pixel. Based on the compensation voltage for holding the voltage component corresponding to the threshold voltage unique to the switching element of each display pixel, and the gradation effective voltage corresponding to the luminance gradation of the display data to the display pixel by applying a write voltage (gradation designating voltage) to each of the display pixels in the selected state, the threshold voltage of the switching element (thin film transistor) is to change over time or the drive history or the like Therefore, even when it is changed (Vth shift), it is possible to suppress the influence and hold the appropriate voltage component (gradation effective voltage) corresponding to the display data in the switching element. Can be emitted with an appropriate luminance gradation.

  As a result, even an amorphous silicon thin film transistor that is susceptible to threshold voltage fluctuations due to changes over time, drive history, etc., can be favorably applied as a switching element for light emission drive. A display pixel (light emission drive circuit) with uniform mobility can be realized by a simple manufacturing process.

Further, in the gradation signal writing operation, the voltage component corresponding to the display data is set by adding the voltage component corresponding to the threshold voltage specific to the switching element provided in each display pixel. A voltage gradation designation type drive control method that applies a built-in voltage can be applied, so that a sufficient voltage component according to display data can be quickly written during a predetermined writing period, and insufficient writing Occurrence can be prevented.
In the non-light-emitting display in which the luminance gradation of the display data is the lowest gradation, a non-light-emitting display voltage having a predetermined voltage value is applied as a gradation signal so that the switching element for light emission driving holds the display data. The voltage component (charge) can be discharged and set to a voltage sufficiently lower than the threshold voltage, so that the unstable state in which the switching element is turned on under the influence of a slight voltage fluctuation is eliminated. And the light-emitting element can be favorably held in a non-light-emitting state (black display state).

  Further, according to the display device and the drive control method thereof according to the present invention, the operation of detecting the threshold voltage specific to the light emission drive switching element (thin film transistor) provided in the display pixel (light emission drive circuit), By executing the display pixels in different specific rows arranged in the display panel for each frame period, either during the display period of the image information (during the display drive control period of the display device) or any one arranged in the display panel Since the threshold voltage (Vth shift state) at the time of execution of the threshold voltage detection operation can be constantly monitored for the display pixels in this row, the writing applied to each display pixel during the display data writing operation The compensation voltage included in the voltage can be set to a voltage value appropriately corresponding to the state of occurrence of the Vth shift, and the switching element (thin film transistor) of each display pixel can be set. The influence of the Vth shift of the threshold voltage can be satisfactorily suppressed, and the display pixel (light emitting element) can be operated to emit light at an appropriate luminance gradation.

In the display device and the drive control method thereof according to the present invention, each display pixel is supplied with either the first voltage that sets the display pixel in the light emitting operation state or the second voltage that sets the non-light emitting operation state. A power supply driving unit that applies a voltage, and each display pixel in a row to which the grayscale signal is supplied from the power supply driving unit includes a selection period and includes a second period as a supply voltage over a period longer than the selection period. It is longer than the selection period during each frame period during the display operation by applying a voltage and setting the display pixels in the row to the non-light emitting operation state for a period longer than the selection period. An appropriate period of black display period can be inserted, and the display quality of moving images can be improved. When a plurality of display pixels arranged on the display panel are divided into a plurality of groups for each of a plurality of rows, a period during which at least a writing operation is performed for each group of display pixels in a row included in the group. During the time when all display pixels in the group are set to the non-light emitting display state (black display state) without performing the light emitting operation, and when the writing operation is completed for the display pixels of all the rows included in the group. In a display operation of moving images realized by continuously displaying a plurality of pieces of image information (still images) by executing display drive control for causing all display pixels of the group to emit light simultaneously Therefore, it is possible to realize a display device having a clear display image quality by suppressing the occurrence of blurring and blurring of the moving image.

Hereinafter, a display device and a drive control method thereof according to the present invention will be described in detail with reference to embodiments.
First, a display driving device and a driving control method applied to a display device according to the present invention will be described with reference to the drawings.

FIG. 1 is a main part configuration diagram showing an embodiment of a display driving device applied to the present invention and a display pixel driven and controlled by the display driving device. Here, the relationship between a specific display pixel arranged on the display panel of the display device and a display drive device that controls the light emission drive of the display pixel will be described.

<Display drive device>
As shown in FIG. 1, the display driving apparatus 100 according to the present embodiment generally includes a shift register / data register unit 110, a display data latch unit 120, a gradation voltage generation unit 130, and a threshold detection voltage analog. -Digital converter (hereinafter abbreviated as "detection voltage ADC", and in the figure abbreviated as "Vth ADC") 140, and threshold compensation voltage digital-analog converter (hereinafter abbreviated as "compensation voltage DAC"). In the drawing, it is expressed as “VthDAC” 150, a threshold data latch unit (in the drawing, expressed as “Vth data latch unit”) 160, a frame memory 170, and a voltage adding unit 180. And a data line input / output switching unit 190.

  The shift register / data register unit (data acquisition means, threshold value acquisition means) 110 is a shift register that sequentially outputs shift signals, not shown, and a digital signal supplied at least from the outside based on the shift signals And a data register for sequentially taking in luminance gradation data. More specifically, an operation of sequentially fetching display data (luminance gradation data) corresponding to the display pixels PX for one row of the display panel, which is sequentially supplied from the outside, and transferring the display data to the display data latch unit 120 described later. Alternatively, the threshold voltage (threshold detection data) of the display pixels PX for one row, which is converted into a digital signal by the detection voltage ADC 140 and held in the threshold data latch unit 160, is sequentially fetched, and a frame memory to be described later The operation of transferring to 170 or the operation of sequentially fetching the threshold compensation data of the display pixels PX for one specific row from the frame memory 170 and transferring them to the threshold data latch unit 160 is selectively executed. To do. Each of these operations will be described in detail later.

The display data latch unit 120 holds the display data (luminance gradation data) of the display pixels PX for one row that is taken in and transferred from the outside by the shift register / data register unit 110.
The gradation voltage generation unit (gradation voltage generation means) 130 is a gradation for causing the organic EL element (current-controlled light emitting element) OEL to perform a light emission operation or a non-light emission operation with a luminance gradation corresponding to display data. As a signal, a gray scale effective voltage (gray scale voltage) Vreal having a predetermined voltage value for causing the organic EL element OEL to emit light at a predetermined luminance gradation, or black without causing the organic EL element OEL to emit light. A function of selectively supplying any one of the non-light emitting display voltages Vzero having a predetermined voltage value for setting the display (minimum luminance gradation) state is provided.

  Here, as a configuration for supplying a gradation effective voltage Vreal having a voltage value corresponding to display data as a gradation signal, for example, based on a gradation reference voltage supplied from power supply means (not shown), A digital-analog converter (D / A converter) that converts a digital signal voltage of each display data held in the display data latch unit 120 into an analog signal voltage, and the analog signal voltage is converted to the above-mentioned gradation effective at a predetermined timing. It is possible to apply a configuration including an output circuit that outputs the voltage Vreal. Details of the gradation effective voltage Vreal will be described later.

  The detection voltage ADC (threshold voltage detection means) 140 is a threshold of a switching element (thin film transistor Tr13) that supplies a light emission driving current to a light emitting element (for example, an organic EL element OEL) provided in each display pixel PX described later. A value voltage (or a voltage component corresponding to the threshold voltage) is taken (measured) as an analog signal voltage and converted into threshold detection data composed of a digital signal voltage.

  A compensation voltage DAC (compensation voltage generation means, detection voltage application means) 150 receives threshold compensation data including digital signal voltages for compensating the threshold voltage of the switching element provided in each display pixel PX. Then, it is converted into a compensation voltage (threshold compensation voltage) Vpth composed of an analog signal voltage. Further, as shown in a drive control method described later, in the operation of measuring the threshold voltage of the switching element by the detection voltage ADC 140 (threshold voltage detection operation), between the gate and the source of the thin film transistor constituting the switching element ( A predetermined detection voltage Vpv can be output so that a potential difference higher than the threshold voltage of the switching element is set (a voltage component is maintained) at both ends of the capacitor Cs. .

  The threshold data latch unit 160 captures and holds threshold detection data converted and generated by the detection voltage ADC 140 for each display pixel PX for one row, and stores the threshold detection data. An operation of sequentially transferring to a frame memory 170 (to be described later) via the shift register / data register unit 110, or a threshold value for each display pixel PX for one row corresponding to the threshold detection data from the frame memory 170 One of the operations of sequentially acquiring and holding the compensation data and transferring the threshold compensation data to the compensation voltage DAC 150 is selectively executed.

  Further, the frame memory (storage means) 170 includes the detection voltage ADC 140 and the threshold data latch unit prior to the writing operation of the display data (luminance gradation data) to each display pixel PX arranged on the display panel. The threshold detection data based on the threshold voltage detected for each display pixel PX for one row by 160 is sequentially taken in via the shift register / data register unit 110 to display one display panel (one frame). Are stored individually for each display pixel PX, and the threshold detection data is used as threshold compensation data, or threshold compensation data corresponding to the threshold detection data is used as a shift register / data register. The data are sequentially output via the unit 110 and transferred to the threshold data latch unit 160 (compensation voltage DAC 150).

  A voltage adding unit (grayscale signal generating means) 180 adds the voltage component output from the grayscale voltage generating unit 130 and the voltage component output from the compensation voltage DAC 150 to a data line input / output switching unit described later. A function of outputting to a data line DL arranged in the column direction of the display panel via 190 is provided. Specifically, in the threshold voltage detection operation for detecting the threshold voltage in each display pixel PX, the detection voltage Vpv output from the compensation voltage DAC 150 is output, and the display pixel PX (light emitting element) At the time of the gradation display operation accompanied by the light emission operation, the gradation effective voltage Vreal output from the gradation voltage generation unit 130 and the compensation voltage Vpth output from the compensation voltage DAC 150 are added together to obtain a total voltage. The component is output as the gradation designation voltage Vdata, and the non-light emitting display operation (black display operation) that does not involve the light emitting operation of the display pixel PX (light emitting element) is output from the gradation voltage generating unit 130. A function of outputting a gradation designation voltage Vdata (0) (or a non-light emission display voltage Vzero) obtained by adding the light emission display voltage Vzero and the compensation voltage Vpth is provided.

  The data line input / output switching unit (signal path switching means) 190 takes in the threshold voltage of the switching element (thin film transistor) provided in each display pixel PX to the detection voltage ADC 140 via the data line DL. The detection voltage Vpv, the gradation effective voltage Vreal, or the non-light emitting display voltage Vzero (or the gradation designation voltage Vdata () selectively output from the voltage detection side switch 191 and the voltage adding unit 180 for measurement. 0)) is provided with a voltage application side switch 192 for supplying each display pixel PX via the data line DL.

  Here, the voltage detection side switch 191 and the voltage application side switch 192 can be configured by, for example, thin film transistors (field effect transistors) having different channel polarities, and as shown in FIG. A channel thin film transistor can be used, and an n channel thin film transistor can be used as the voltage application switch 192. The gate terminals (control terminals) of these thin film transistors are connected to the same signal line, and the ON and OFF states are controlled based on the signal level of the switching control signal AZ applied to the signal line.

<Display pixel>
Further, as shown in FIG. 1, the display pixels PX according to the present embodiment are arranged in the column direction (vertical direction in the drawing) and the selection line SL arranged in the row direction (horizontal direction in the drawing) of the display panel. A current-controlled light-emitting element that is arranged near each intersection with the data line DL, for example, each composed of an organic EL element OEL, and a light-emitting drive current having a current value corresponding to display data is supplied to the light-emitting element. And a light emission drive circuit DC.

In the light emission driving circuit DC, for example, a gate terminal ( second control terminal) is applied to the selection line SL, and a drain terminal and a source terminal (one end and the other end of the second current path) are applied with a predetermined supply voltage Vsc. The thin film transistor ( first switch means) Tr11 connected to the supply voltage line VL and the contact N11, and the gate terminal ( third control terminal) are connected to the selection line SL, and the source terminal and drain terminal ( third current path of the third current path). A thin film transistor ( second switch means) Tr12 having one end and the other end connected to the data line DL and the contact N12, respectively, and a gate terminal ( first control terminal) to the contact N11 and a drain terminal and a source terminal ( first A thin film transistor (light emitting drive element) Tr13 having one end and the other end of the current path connected to the supply voltage line VL and a contact (connection contact) N12; Between 11 and contacts N12 (thin film transistor Tr13 gate - between the source terminal) has a capacitor Cs connected, the configuration with. Here, the thin film transistor Tr13 corresponds to a transistor element for light emission driving that is a target whose threshold voltage is measured by the detection voltage ADC 140 and the threshold data latch unit 160 in the display driving device 100 described above.

  The organic EL element (light emitting element) OEL has an anode terminal connected to the contact N12 of the light emission drive circuit DC, and a common voltage Vcom applied to the cathode terminal. Here, the common voltage Vcom is used in a write operation period in which a grayscale signal (grayscale current or non-light emitting display voltage) corresponding to display data is supplied to the light emission drive circuit DC in a display drive operation described later. The light emission driving current is supplied to the organic EL element (light emitting element) OEL which is equal to or higher than the supply voltage Vsc set to the low potential (Vs). In the light emission operation period in which the light emission operation is performed at a predetermined luminance gradation, the potential is set to an arbitrary potential (for example, ground potential GND) that is lower than the supply voltage Vsc set to the high potential (Ve). (Vs ≦ Vcom <Ve).

  Here, the capacitor Cs may be a parasitic capacitance formed between the gate and the source of the thin film transistor Tr13. In addition to the parasitic capacitance, a capacitor is further connected in parallel between the contact N11 and the contact N12. There may be. The thin film transistors Tr11 to Tr13 are not particularly limited. For example, by forming all the thin film transistors Tr11 to Tr13 with n channel thin film transistors, the n channel amorphous silicon thin film transistors can be favorably applied. . In this case, by applying an already established amorphous silicon manufacturing technique, a light emission driving circuit composed of an amorphous silicon thin film transistor having stable element characteristics (such as electron mobility) can be manufactured by a relatively simple manufacturing process. In the following description, a case where all the thin film transistors Tr11 to Tr13 are configured by n-channel thin film transistors will be described. In the above description, the light emitting element driven to emit light by the light emission driving circuit DC is the organic EL element OEL. However, the light emitting element in the present invention is not limited to the organic EL element OEL, and is a current control type light emitting element. Any other light emitting element such as a light emitting diode may be used.

<Display Drive Device / Display Pixel Drive Control Method>
Next, a drive control method (drive control operation) in a case where gradation display is performed by causing the light emitting elements of the display pixels to perform a light emission operation in the display driving device having the above-described configuration will be described with reference to the drawings.

  The drive control operation in the display drive device 100 according to the present embodiment is roughly divided into display pixels PX (light emission) arranged on the display panel at an arbitrary timing prior to a display drive operation (writing operation, light emission operation) described later. Threshold voltage detection operation (threshold voltage detection period; first time) for measuring and storing the threshold voltage of the thin film transistor Tr13 for light emission driving (switching element; light emission driving element) provided in the drive circuit DC) Step), and after completion of the threshold voltage detection operation, the light emission driving thin film transistor Tr13 provided in each display pixel PX has a voltage component (compensation voltage) corresponding to the threshold voltage unique to the thin film transistor Tr13. Then, a gradation designation voltage obtained by adding the gradation signal corresponding to the display data (gradation effective voltage having a predetermined voltage value) is written, and the gradation signal corresponding to the gradation signal is written. Display drive operation for light emission operation of the organic EL element OEL at Nozomu luminance gradation (the display drive period), is configured to include a.

Hereinafter, each control operation will be described.
(Threshold voltage detection operation)
FIG. 2 is a timing chart showing the threshold voltage detection operation in the display driving apparatus according to the present embodiment. 3 is a conceptual diagram illustrating a voltage application operation in the display driving apparatus according to the present embodiment, and FIG. 4 is a conceptual diagram illustrating a voltage convergence operation in the display driving apparatus according to the present embodiment. These are the conceptual diagrams which show the voltage reading operation | movement in the display drive device which concerns on this embodiment. FIG. 6 is a diagram illustrating an example of drain-source current characteristics when the gate-source voltage is set to a predetermined condition and the drain-source voltage is modulated in an n-channel thin film transistor. .

  As shown in FIG. 2, the threshold voltage detection operation in the display drive device according to the present embodiment is performed by displaying pixels from the display drive device 100 via the data line DL within a predetermined threshold voltage detection period Tdec. A threshold voltage detection voltage (detection voltage Vpv) is applied to PX, and the detection voltage Vpv is applied between the gate and the source of the light emission driving thin film transistor Tr13 provided in the light emission driving circuit DC of the display pixel PX. A voltage application period (detection voltage application step) Tpv that holds the corresponding voltage component (that is, charges corresponding to the detection voltage Vpv are accumulated in the capacitor Cs), and the gate-source of the thin film transistor Tr13 in the voltage application period Tpv A part of the voltage component (charge accumulated in the capacitor Cs) held therebetween is discharged, and the drain-source current of the thin film transistor Tr13 is discharged. Only a voltage component (charge) corresponding to the threshold voltage Vth13 of Ids is held between the gate and source of the thin film transistor Tr13 (remains in the capacitor Cs), and after the elapse of the voltage convergence period Tcv, the thin film transistor The voltage component (voltage value based on the charge remaining in the capacitor Cs; threshold voltage Vth13) held between the gate and source of Tr13 is measured, converted into digital data, and stored in a predetermined storage area of the frame memory 170. And a voltage reading period (threshold voltage detection step) Trv to store (store) (Tdec ≧ Tpv + Tcv + Trv).

  Here, the threshold voltage Vth13 of the drain-source current Ids of the thin film transistor Tr13 is an operating boundary where the drain-source current Ids of the thin film transistor Tr13 starts to flow when a slight voltage is further applied between the drain and source. The gate-source voltage Vgs of the thin film transistor Tr13. In particular, the threshold voltage Vth13 measured in the voltage reading period Trv according to the present embodiment varies with the driving history (light emission history), usage time, and the like with respect to the threshold voltage in the initial manufacturing state of the thin film transistor Tr13 ( The threshold voltage at the time of execution of the threshold voltage detection operation after occurrence of (Vth shift) is shown.

Hereinafter, each operation period related to the threshold voltage detection operation will be described in more detail.
(Voltage application period)
First, in the voltage application period Tpv, as shown in FIGS. 2 and 3, an on-level (high level) selection signal Ssel is applied to the selection line SL of the light emission drive circuit DC, and the supply voltage line VL is applied to the supply voltage line VL. A low-potential supply voltage Vsc (= Vs) is applied. Here, the low potential supply voltage Vsc (= Vs) may be a voltage equal to or lower than the common voltage Vcom, and may be, for example, the ground potential GND.

  On the other hand, in synchronization with this timing, the switching control signal AZ is set to the high level, the voltage application side switch 192 is set to the on state, the voltage detection side switch 191 is set to the off state, and the gradation voltage generating unit 130 Is stopped or cut off, the threshold voltage detection voltage Vpv output from the compensation voltage DAC 150 is converted into a voltage adding unit 180 and a data line input / output switching unit 190 (voltage application side switch 192). And applied to the data line DL.

  Thereby, the thin film transistors Tr11 and Tr12 provided in the light emission drive circuit DC constituting the display pixel PX are turned on, and the supply voltage Vsc is supplied to the gate terminal of the thin film transistor Tr13 and one end side of the capacitor Cs (contact N11) via the thin film transistor Tr11. The detection voltage Vpv applied to the data line DL is applied to the source terminal of the thin film transistor Tr13 and the other end side (contact N12) of the capacitor Cs via the thin film transistor Tr12.

  Here, in the display pixel PX (light emission drive circuit DC), with respect to the n-channel type thin film transistor Tr13 that supplies the light emission drive current to the organic EL element OEL, the drain-source voltage at the predetermined gate-source voltage Vgs. When the change characteristic of the drain-source current Ids when Vds is modulated is verified, it can be represented by a characteristic diagram as shown in FIG.

  In FIG. 6, the horizontal axis represents the partial pressure of the thin film transistor Tr13 and the partial pressure of the organic EL element OEL connected in series thereto, and the vertical axis represents the current value of the drain-source current Ids of the thin film transistor Tr13. A one-dot chain line in the figure is a boundary line of the threshold voltage between the gate and the source of the thin film transistor Tr13, the left side of the boundary line is an unsaturated region, and the right side is a saturated region. The solid line shows the gate-source voltage Vgs of the thin film transistor Tr13, the voltage Vgsmax at the time of light emission operation at the maximum luminance gradation, and the voltage Vgs1 at the time of light emission operation at any (different) luminance gradation below the maximum luminance gradation. The graph shows the change characteristics of the drain-source current Ids when the drain-source voltage Vds of the thin film transistor Tr13 is modulated when fixed to (<Vgsmax) and Vgs2 (<Vgs1). A broken line is a load characteristic line (EL load line) when the organic EL element OEL is caused to emit light, and a voltage on the right side of the EL load line is a voltage between the supply voltage Vsc and the common voltage Vcom (as an example, in the drawing). 20V), and the left side of the EL load line corresponds to the drain-source voltage Vds of the thin film transistor Tr13. The partial pressure of the organic EL element OEL gradually increases as the luminance gradation increases, that is, as the current value of the drain-source current Ids (light emission drive current≈gradation current) of the thin film transistor Tr13 increases.

  In FIG. 6, in the unsaturated region, even if the gate-source voltage Vgs of the thin film transistor Tr13 is set constant, the drain-source current Ids is increased as the drain-source voltage Vds of the thin film transistor Tr13 increases. The value is significantly increased (changes). On the other hand, in the saturation region, when the gate-source voltage Vgs of the thin film transistor Tr13 is set constant, even if the drain-source voltage Vds increases, the drain-source current Ids of the thin film transistor Tr13 does not increase so much and is substantially constant. It becomes.

  Here, in the voltage application period Tpv, the detection voltage Vpv applied from the compensation voltage DAC 150 to the data line DL (further, the source terminal of the thin film transistor Tr13 of the display pixel PX (light emission drive circuit DC)) has a low potential. In the characteristic diagram shown in FIG. 6 which is sufficiently lower than the set supply voltage Vsc (= Vs), the drain-source voltage Vds in the region where the gate-source voltage Vgs of the thin film transistor Tr13 exhibits saturation characteristics is obtained. Is set to such a voltage value. In the present embodiment, the detection voltage Vpv may be set to a maximum voltage that can be applied from the compensation voltage DAC 150 to the data line DL, for example.

Further, the detection voltage Vpv is set so as to satisfy the following expression (1).
| Vs-Vpv |> Vth12 + Vth13 (1)
In the above equation (1), Vth12 is a threshold voltage between the drain and source of the thin film transistor Tr12 when the on-level selection signal Ssel is applied to the gate terminal of the thin film transistor Tr12. In addition, since a low-potential supply voltage Vsc (= Vs) is applied to both the gate terminal and the drain terminal of the thin film transistor 13 and are substantially equal to each other, Vth13 is a voltage between the drain and source of the thin film transistor Tr13. It is a threshold voltage, and is also a threshold voltage between the gate and source of the thin film transistor Tr13. Although Vth12 + Vth13 gradually increases with time, the potential difference of (Vs−Vpv) is set large so as to always satisfy the equation (1).

  Thus, by applying a potential difference Vcp (both end potential Vc) larger than the threshold voltage Vth13 of the thin film transistor Tr13 between the gate and the source of the thin film transistor Tr13 (that is, both ends of the capacitor Cs), the voltage Vcp is applied. A corresponding large current Ipv for detection flows forcibly from the supply voltage line VL toward the compensation voltage DAC 150 via the drain-source of the thin film transistor Tr13. Therefore, electric charges corresponding to the potential difference based on the detection current Ipv are quickly accumulated at both ends of the capacitor Cs (that is, the voltage Vcp is charged in the capacitor Cs). In the voltage application period Tpv, not only charges are accumulated in the capacitor Cs, but also the detection current Ipv flows through other capacitance components in the current route from the supply voltage line VL to the data line DL, so Accumulation is performed.

  At this time, since the common voltage Vcom (= GND) higher than the low-potential supply voltage Vsc (= Vs) applied to the supply voltage line VL is applied to the cathode terminal of the organic EL element OEL, the organic EL element The anode-cathode is set between the anode and the cathode of the element OEL, and the light emission drive current does not flow through the organic EL element OEL, and the light emission operation is not performed.

(Voltage convergence period)
Next, in the voltage convergence period Tcv after the end of the voltage application period Tpv, as shown in FIGS. 2 and 4, an on-level selection signal Ssel is applied to the selection line SL, and a low potential is applied to the supply voltage line VL. When the switching control signal AZ is switched to the low level while the supply voltage Vsc (= Vs) is applied, the voltage detection side switch 191 is set to the on state and the voltage application side switch 192 is Set to off state. Further, the output of the detection voltage Vpv from the compensation voltage DAC 150 is stopped. Accordingly, since the thin film transistors Tr11 and Tr12 are kept on, the display pixel PX (light emission drive circuit DC) is electrically connected to the data line DL, but the voltage application to the data line DL is performed. Therefore, the other end side (contact N12) of the capacitor Cs is set to a high impedance state.

  At this time, the gate voltage of the thin film transistor Tr13 is held by the electric charge (both-end potential Vc = Vcp> Vth13) accumulated in the capacitor Cs in the voltage application period Tpv described above, and the thin film transistor Tr13 is held in the ON state. Since the current continues to flow between the drain and source, the potential on the source terminal side (contact N12; the other end side of the capacitor Cs) of the thin film transistor Tr13 gradually increases so as to approach the potential on the drain terminal side (supply voltage line VL side). I will do it.

  As a result, a part of the electric charge accumulated in the capacitor Cs is discharged, the gate-source voltage Vgs of the thin film transistor Tr13 is lowered, and finally converges on the threshold voltage Vth13 of the thin film transistor Tr13. Change. Along with this, the drain-source current Ids of the thin film transistor Tr13 decreases, and the current flow finally stops.

  Even during this voltage convergence period Tcv, the potential of the anode terminal (contact N12) of the organic EL element OEL is equal to or less than the common voltage Vcom on the cathode terminal side. No voltage or reverse bias voltage is still applied to the organic EL element OEL, and the organic EL element OEL does not perform light emission.

(Voltage reading period)
Next, in the voltage reading period Trv after the lapse of the voltage convergence period Tcv, as shown in FIGS. 2 and 5, an on-level selection signal Ssel is applied to the selection line SL as in the voltage convergence period Tcv. , The detection voltage ADC 140 electrically connected to the data line DL and the threshold in the state where the low-potential supply voltage Vsc (= Vs) is applied to the supply voltage line VL and the switching control signal AZ is set to the low level. The value data latch unit 160 measures the potential (detection voltage Vdec) of the data line DL.

  Here, the data line DL after the lapse of the voltage convergence period Tcv is in a state of being connected to the source terminal (contact N12) side of the thin film transistor Tr13 through the thin film transistor Tr12 set in the ON state. Thus, the potential on the source terminal (contact N12) side of the thin film transistor Tr13 corresponds to the potential on the other end side of the capacitor Cs in which charges corresponding to the threshold voltage Vth13 of the thin film transistor Tr13 are accumulated.

  On the other hand, the potential on the gate terminal (contact N11) side of the thin film transistor Tr13 is a potential on one end side of the capacitor Cs in which electric charges corresponding to the threshold voltage Vth13 of the thin film transistor Tr13 are accumulated, and at this time, it is set to the on state. The thin film transistor Tr11 is connected to a low potential supply voltage Vsc.

  As a result, the potential of the data line DL measured by the detection voltage ADC 140 corresponds to the potential on the source terminal side of the thin film transistor Tr13 or the potential corresponding to the potential, so the detection voltage Vdec and the preset voltage Is determined based on the difference (potential difference) from the low-potential supply voltage Vsc (for example, the ground potential GND), that is, the gate-source voltage Vgs of the thin film transistor Tr13 (the potential Vc across the capacitor Cs), that is, the thin film transistor Tr13. Threshold voltage Vth13 or a voltage corresponding to the threshold voltage Vth13 can be detected.

  Then, the threshold voltage Vth13 (analog signal voltage) of the thin film transistor Tr13 detected in this way is converted into threshold detection data composed of a digital signal voltage by the detection voltage ADC 140, and the threshold data latch unit 160 is converted. The threshold detection data of each display pixel PX for one row is sequentially read out by the shift register / data register unit 110 and stored (stored) in a predetermined storage area of the frame memory 170. Here, the threshold voltage Vth13 of the thin film transistor Tr13 provided in the light emission drive circuit DC of each display pixel PX has a different degree of variation (Vth shift) depending on the drive history (light emission history) in each display pixel PX. The frame memory 170 stores threshold value detection data unique to each display pixel PX.

  Such a series of threshold voltage detection operations are executed at an arbitrary timing prior to a display driving operation described later, for example, when the system (display device) is started up or resumed from a hibernation state. As will be described in the drive control method of the apparatus, all the display pixels arranged in the display panel are executed within a predetermined threshold voltage detection period.

(Display drive operation: gradation display operation)
First, a drive control method in a case where a light emitting element emits light with a desired luminance gradation (gradation display operation) in the display driving device and the display pixel having the above-described configuration will be described with reference to the drawings.

  FIG. 7 is a timing chart showing a drive control method when performing a gradation display operation in the display drive apparatus according to the present embodiment. FIG. 8 is a conceptual diagram showing a data writing operation in the drive control method (gradation display operation) according to the present embodiment, and FIG. 9 is a drive control method (gradation display operation) according to the present embodiment. It is a conceptual diagram which shows light emission operation | movement.

  As shown in FIG. 7, the display driving operation in the display driving apparatus according to the present embodiment is performed by displaying pixels from the display driving apparatus 100 via the data line DL within a predetermined display driving period (one processing cycle period) Tcyc. A voltage based on a predetermined compensation voltage Vpth and a grayscale effective voltage Vreal corresponding to display data, for example, a voltage that is the sum of the compensation voltage Vpth and the grayscale effective voltage Vreal is added to PX as a grayscale designation voltage Vdata. Voltage component corresponding to the threshold voltage Vth13 of the drain-source current Ids of the thin film transistor Tr13 between the gate and the source of the light emission driving thin film transistor Tr13 provided in the light emission drive circuit DC of the display pixel PX. And a writing operation period (second to fourth steps, data writing step) for holding (writing) a voltage component corresponding to display data (gradation effective voltage). Based on Twrt and the total voltage component (total charge accumulated in the capacitor Cs) held between the gate and source of the thin film transistor Tr13, an emission driving current having a current value corresponding to display data is organically generated. It is set so as to include a light emission operation period (gradation light emission step) Temp that causes the EL element OEL to emit light at a predetermined luminance gradation (Tcyc ≧ Twrt + Tem).

  Here, the one processing cycle period applied to the display driving period Tcyc according to the present embodiment is set to a period required for the display pixel PX to display image information for one pixel in one frame image, for example. Is done. That is, as described in the drive control method for the display device to be described later, when one frame image is displayed on a display panel in which a plurality of display pixels PX are arranged in a matrix in the row direction and the column direction, the one processing cycle period. Tcyc is set to a period required for the display pixels PX for one row to display one row of images in one frame image.

Hereinafter, each operation period related to the display driving operation will be described in more detail.
(Write operation period)
First, in the write operation period Twrt, as shown in FIGS. 7 and 8, an on-level (high level) selection signal Ssel is applied to the selection line SL of the light emission drive circuit DC, and the supply voltage line VL is also applied. Is applied with a low-potential supply voltage Vsc (= Vs; for example, ground potential GND).

  Thereby, the thin film transistors Tr11 and Tr12 provided in the light emission drive circuit DC are turned on, and the supply voltage Vsc is applied to the gate terminal (contact N11; one end side of the capacitor Cs) of the thin film transistor Tr13 through the thin film transistor Tr11. The source terminal (contact N12) of the thin film transistor Tr13 is electrically connected to the data line DL via the thin film transistor Tr12.

  On the other hand, in synchronization with this timing, the switching control signal AZ is set to the high level, the voltage application side switch 192 is set to the on state, the voltage detection side switch 191 is set to the off state, and the voltage adding unit 180 is The compensation voltage Vpth generated by the compensation voltage DAC 150 is output (second step, compensation voltage generation step), and the gradation effective voltage Vreal generated by the gradation voltage generator 130 is output (third). Step, gradation voltage generation step).

  In the voltage adding unit 180, the compensation voltage Vpth output from the compensation voltage DAC 150 and the grayscale effective voltage Vreal output from the grayscale voltage generation unit 130 are added together, and the total voltage component is the grayscale designation voltage Vdata. Is applied to the data line DL via the data line input / output switching unit 190 (voltage application side switch 192). Here, the voltage polarity of the gradation designation voltage Vdata is set to a polarity in which a current flows from the supply voltage line VL through the thin film transistor Tr13, the contact N12, the thin film transistor Tr12, and the data line DL in the direction of the voltage adding unit 180.

  As a result, the thin film transistor Tr11 provided in the display pixel PX (light emission drive circuit DC) is turned on, and the low-potential supply voltage Vsc (= Vs) is connected to the gate of the thin film transistor Tr13 and one end side of the capacitor Cs via the thin film transistor Tr11. In addition to being applied to (contact N11), the thin film transistor Tr12 is turned on, and the gradation designation voltage Vdata set at a low potential with respect to the supply voltage Vsc is supplied via the data line DL to the source terminal side of the thin film transistor Tr13 ( By being applied to the contact N12; the other end of the capacitor Cs), it corresponds to the difference between the gradation designation voltage Vdata and the low potential supply voltage Vsc between the gate and source of the thin film transistor Tr13 (both ends of the capacitor Cs). Voltage component (when the supply voltage Vsc is the ground potential GND, Voltage component corresponding to the pressure Vdata) is held (fourth step, data writing step).

  That is, a potential difference corresponding to the sum (Vth13 + Vreal) of the threshold voltage Vth13 inherent to the thin film transistor Tr13 and the gradation effective voltage Vreal is generated at both ends of the capacitor Cs connected between the gate and the source of the thin film transistor Tr13. Charges corresponding to the potential difference are accumulated. Since the potential difference formed between the gate and the source of the thin film transistor Tr13 by this writing operation becomes a voltage value exceeding the threshold voltage Vth13 inherent to the thin film transistor Tr13, the thin film transistor Tr13 is turned on and the supply voltage line VL is turned on. Current flows through the thin film transistor Tr13, the contact N12, the thin film transistor Tr12, and the data line DL in the direction of the display driving device 100 (voltage adding unit 180).

  Here, in the write operation period Twrt, the compensation voltage Vpth output from the compensation voltage DAC 150 is detected for each display pixel PX by the detection voltage ADC 140 and the threshold data latch unit 160 in the threshold voltage detection operation described above. Based on threshold detection data detected and individually stored for each display pixel PX in the frame memory 170, the threshold voltage Vth13 specific to the thin film transistor Tr13 of each display pixel PX (light emission drive circuit DC) is compensated. The voltage value is such that a voltage component corresponding to the threshold voltage Vth13 can be held between the gate and source of the thin film transistor Tr13 (both ends of the capacitor Cs) by applying the compensation voltage Vpth. Is set.

  More specifically, as described above, when n-channel amorphous silicon thin film transistors are applied as the thin film transistors Tr11 to Tr13 constituting the light emission drive circuit DC provided in the display pixel PX, the threshold voltage of the amorphous silicon thin film transistor is applied. Has a device characteristic that a phenomenon (Vth shift) is likely to occur. Here, the variation amount of the threshold voltage in the Vth shift is caused by the driving history, the usage time, and the like of the thin film transistor. Therefore, the variation amount is different for each thin film transistor.

  Therefore, in this embodiment, the threshold voltage detection operation is performed after the Vth shift for the thin film transistor Tr13 for light emission driving that sets the light emission luminance of the organic EL element (light emitting element) OEL in each display pixel PX. A threshold voltage at the time of executing the threshold voltage detection operation is individually detected and stored as threshold detection data in the frame memory 170, and when writing the display data for the display pixel, a threshold unique to each thin film transistor. By holding the voltage component corresponding to the voltage, the fluctuation of the threshold voltage due to the Vth shift is compensated.

  Therefore, even when the threshold voltage Vth13 of the thin film transistor Tr13 is shifted by Vth due to the light emission history (driving history) or the like, the voltage component (grayscale effective voltage Vreal) corresponding to the grayscale signal (display data) appropriately. Writing can be performed quickly and sufficiently within the writing operation period Twrt.

  At this time, a supply voltage Vsc (= Vs) having a low potential is applied to the supply voltage line VL, and a gradation designation voltage Vdata lower than the supply voltage Vsc is applied to the contact N12. Therefore, since the potential applied to the anode terminal (contact N12) of the organic EL element OEL is equal to or lower than the potential Vcom (GND) of the cathode terminal, a reverse bias voltage is applied to the organic EL element OEL. A light emission drive current does not flow through the element OEL, and no light emission operation is performed.

(Light emission operation period)
Next, in the light emission operation period Tem after the end of the write operation period Twrt, as shown in FIGS. 7 and 9, an off level (low level) selection signal Ssel is applied to the selection line SL, and the supply voltage line VL is applied. A high potential supply voltage Vsc (= Ve) is applied. In synchronism with this timing, the output operation of the gradation effective voltage Vreal by the gradation voltage generator 130 and the compensation voltage Vpth by the compensation voltage DAC 150 is stopped.

  Thereby, the thin film transistors Tr11 and Tr12 provided in the light emission drive circuit DC are turned off, and the supply voltage Vsc to the gate terminal (contact N11; one end side of the capacitor Cs) and the drain terminal of the thin film transistor Tr13 is cut off. At the same time, since the electrical connection between the data line DL and the source terminal of the thin film transistor Tr13 (contact N12; the other end of the capacitor Cs) is cut off, the charge accumulated in the capacitor Cs during the write operation period Twrt described above. Retained.

  Note that, during the light emission operation period Tem, the high-potential supply voltage Vsc (= Ve) applied to the supply voltage line VL is an anode necessary for causing the organic EL element OEL to perform light emission operation at the maximum luminance gradation (MSB). The voltage value is set to be equal to or higher than the voltage (a positive voltage that is forward biased with respect to the voltage Vcom connected to the cathode side of the organic EL element OEL).

Specifically, the high-potential supply voltage Vsc (= Ve) is set to a voltage value that satisfies the following expression (2).
| Ve-Vcom |> Vdsmax + Velmax (2)
In the above equation (2), Vdsmax is the saturation shown in FIG. 6 between the drain and source of the thin film transistor Tr13 when the gradation designation voltage Vdata for performing the light emission operation at the maximum luminance gradation is applied. This is the maximum voltage value between the drain and source of the thin film transistor Tr13 that reaches the region. Velmax is a partial pressure of the organic EL element OEL at the maximum luminance gradation.

  Thus, the sum (Vth13 + Vreal) of the voltage components charged in the capacitor Cs during the write operation is held as the potential Vc across the capacitor Cs, whereby the gate-source voltage Vgs of the thin film transistor Tr13 (ie, the contact N11). The thin film transistor Tr13 is kept on.

  Therefore, during the light emission operation period Tem, as shown in FIG. 10, the light emission drive current Iem flows from the supply voltage line VL to the organic EL element OEL through the thin film transistor Tr13 and the contact N12, and the organic EL element OEL is driven to emit light. Light is emitted at a predetermined luminance gradation corresponding to the current value of the current Iem. Here, since the electric charge (both-end potential Vc) held in the capacitor Cs during the light emission operation period Tem corresponds to a potential difference corresponding to the gradation designation voltage Vdata (Vth13 + Vreal) in the thin film transistor Tr13, the organic EL element The light emission drive current Iem flowing through the OEL has a current value (Iem≈Idata) corresponding to a predetermined light emission state (luminance gradation) based on the gradation effective voltage Vreal included in the gradation designation voltage Vdata. The organic EL element OEL continuously emits light with a luminance gradation corresponding to display data (gradation effective voltage).

  As described above, according to the display drive device and the display pixel according to the present embodiment, the display data is written according to the voltage component corresponding to the threshold voltage Vth13 between the gate and the source of the thin film transistor Tr13 and the display data. By maintaining the sum of the voltage components corresponding to the grayscale effective voltage Vreal, the organic EL element (light emitting element) OEL is substantially based on the voltage component (grayscale voltage Vdata) corresponding to the grayscale effective voltage Vreal. It is possible to apply a voltage gradation designation type drive control method in which the light emission drive current Iem to be flown is controlled to emit light at a predetermined luminance gradation.

  Therefore, compared to the current gray scale designation method in which insufficient writing of display data (gray scale signal) occurs depending on the luminance gray scale (particularly low gray scale operation) when the light emitting element is operated to emit light. Even during the gradation operation, a gradation signal (gradation designation voltage) can be quickly written to each display pixel, and an appropriate light emitting operation according to display data can be realized in all luminance gradations.

  In particular, in writing operation, in addition to the gradation effective voltage for setting the light emission luminance of the light emitting element, the voltage component corresponding to the threshold voltage specific to the switching element of each display pixel acquired by the threshold voltage detecting operation Even when a Vth shift in which the threshold voltage fluctuates due to the driving history or usage time of the switching element occurs, the switching element is reliably set near the operation boundary. In addition, since the voltage component corresponding to the display data can be added and held, the influence of the Vth shift can be suppressed even when the amorphous silicon thin film transistor is applied to the switching element. It is possible to realize an appropriate light emission operation according to the above.

  Further, since the gradation effective voltage can be set to a voltage value obtained by adding the gradation effective voltage and the threshold voltage specific to the switching element of each display pixel, the gradation effective voltage is Without considering the threshold voltage of the switching element, it can be set to a voltage value corresponding only to display data (luminance gradation data). Therefore, the processing load for generating the gradation effective voltage in the gradation voltage generating unit is reduced.

  In the present embodiment, in the threshold voltage detection operation that is performed prior to the display drive operation, the voltage is applied to the light emission drive circuit DC (on the source terminal side of the thin film transistor Tr13) of each display pixel PX during the voltage application period Tpv. Although the configuration of the display driving device and the driving control method for applying the detection voltage Vpv to the data line DL from the compensation voltage DAC 150 via the voltage adding unit 180 and the voltage application side switch 192 have been shown, the present invention is not limited to this. For example, as shown below, a dedicated power source for applying the detection voltage Vpv to the data line DL may be provided.

FIG. 10 is a main part configuration diagram showing another configuration example of the display driving apparatus according to the present embodiment. Here, the description of the same configuration as the above-described embodiment is omitted.
As shown in FIG. 10, the display driving device according to this configuration example includes a detection voltage Vpv that outputs a detection voltage Vpv separately from the compensation voltage DAC 150 in addition to the above-described configuration of the display driving device 100 (see FIG. 1). The voltage power supply 151 has a configuration, and the compensation voltage DAC 150 (compensation voltage Vpth) and the gradation voltage generation unit 130 (gradation effective voltage Vreal, no light emission) are input sources of voltage components to the voltage addition unit 180. In addition to the display voltage Vzero), the detection voltage power supply 151 (detection voltage Vpv) is connected.

  According to this, in the above-described voltage application period Tpv, only the control for setting the output from the compensation voltage DAC 150 and the gradation voltage generation unit 130 to the stopped state or the cutoff state is performed, and the detection voltage from the detection voltage power source 190 is detected. Since the voltage Vpv can be applied to the data line DL via the voltage adder 180, the processing load for the output operation of the detection voltage Vpv in the compensation voltage DAC 150 can be reduced.

(Display drive operation: Non-light emitting display operation)
Next, a driving control method in the case of performing a non-light emitting display (black display) operation in which the light emitting element does not perform a light emitting operation in the display driving device and the display pixel having the above-described configuration will be described with reference to the drawings.

  FIG. 11 is a timing chart showing an example of a drive control method when performing a non-light emitting display operation in the display drive device according to the present embodiment. FIG. 12 is a conceptual diagram showing a data writing operation in the drive control method (non-light emitting display operation) according to the present embodiment, and FIG. 13 is a drive control method (non-light emitting display operation) according to the present embodiment. It is a conceptual diagram which shows non-light-emission operation | movement. Here, the description of the drive control equivalent to the gradation display operation described above is simplified or omitted.

  As shown in FIG. 11, the drive control operation in the display drive device according to the present embodiment is the light emission provided in each display pixel PX after the above-described threshold voltage detection operation (threshold voltage detection period Tdec). A compensation voltage Vpth for holding a voltage component corresponding to the threshold voltage Vth13 inherent in the driving thin film transistor Tr13 and a non-light emission for discharging a voltage component corresponding to the threshold voltage Vth13 and holding a sufficiently low voltage It is configured by a control method for executing a display driving operation (display driving period) for setting the organic EL element OEL to a non-light emitting state by applying a gradation designation voltage Vdata (0) obtained by adding the display voltage Vzero.

  As the gradation designation voltage Vdata (0) for setting the organic EL element OEL to the non-light emitting state, a voltage component obtained by adding the compensation voltage Vpth and the non-light emitting display voltage Vzero by the voltage adding unit 180 described above is used. In addition to the technique, for example, a non-light emitting display voltage having a certain voltage value capable of holding a voltage component sufficiently lower than the threshold voltage Vth13 inherent in the light emission driving thin film transistor Tr13 provided in each display pixel PX. A method using only Vzero may be applied.

  That is, in the drive control operation when performing the above-described gradation display operation, the supply voltage Vsc is changed when the write operation period Twrt in the display drive operation (display drive period Tcyc) shifts to the light emission operation period Temp. It is set to be displaced from a low potential (Vs) to a high potential (Ve). For this reason, a phenomenon occurs in which the potential (gate potential) applied to the gate terminal (contact N11) of the thin film transistor Tr13 rises due to the displacement of the charge held in the capacitive component parasitic on the thin film transistor Tr11.

  Here, when the luminance gradation based on the display data is the lowest gradation (black display state), the gradation designation is performed when the voltage value of the gradation effective voltage is set to a minute state or 0 V corresponding to the luminance gradation. The voltage Vdata is substantially equal to the compensation voltage Vpth, and the voltage (both end potential Vc) charged in the capacitor Cs in the write operation period Twrt is in the vicinity of the threshold voltage Vth13 unique to the thin film transistor Tr13. For this reason, even when a slight change in gate potential occurs due to the transition from the write operation period Twrt to the light emission operation period Tem, the thin film transistor Tr13 is turned on and the light emission drive current Iem flows, and the display is performed. There is a possibility that the non-light emitting display (black display) operation corresponding to the data may not be realized (that is, the non-light emitting display operation becomes unstable).

  In order to stabilize such a non-light emitting display operation, the voltage component charged in the capacitor Cs is discharged in the light emitting operation period Tem, and the gate-source voltage Vgs of the thin film transistor Tr13 (the potential Vc across the capacitor Cs). ) Is set sufficiently lower than the threshold voltage Vth13 inherent to the thin film transistor Tr13, more preferably, 0 V (that is, the contact N11 and the contact N12 are set to the same potential).

  In order to realize such a voltage state, when the current gray scale designation type drive control method as shown in the prior art is applied, the gray scale current (gray scale signal) of a minute current value corresponding to black display is applied. Is required to perform a write operation, and a relatively long time is required to discharge the charge accumulated in the capacitor Cs to make the gate-source voltage Vgs a desired charge amount (voltage value). To do. In particular, in the writing operation period Twrt of the previous display driving period (one processing cycle period) Tcyc, the closer the voltage component (both end potential Vc) charged to the capacitor Cs is to the maximum luminance gradation voltage, Since the amount of stored charge is large, it takes a longer time to discharge the charge to a desired voltage value.

  Therefore, in the display drive device according to the present embodiment, as shown in FIG. 1, the gradation voltage generation unit 130 causes the organic EL element (light emitting element) OEL to emit light with a predetermined luminance gradation according to display data. In addition to the means for generating and supplying the gradation effective voltage Vreal for generating, the non-light emitting display voltage Vzero for generating the darkest display (black display) operation without causing the organic EL element OEL to perform the light emission operation is generated and supplied. And a voltage component (gradation designation voltage Vdata (0)) based on the compensation voltage Vpth generated by the compensation voltage DAC 150 and the non-light emitting display voltage Vzero at the lowest luminance gradation (black display state). It is configured to apply to the line DL or to directly apply the non-light emitting display voltage Vzero.

  In the present embodiment, the case where the gradation voltage generation unit 130 generates and outputs the non-light emitting display voltage Vzero is shown, but the present invention is not limited to this, and for example, the gradation voltage generation unit A dedicated power supply for outputting the non-light emitting display voltage Vzero may be provided separately from 130.

  Then, the drive control method in the display drive device having such a configuration is as shown in FIG. 11, in the display drive operation after the above-described threshold voltage detection operation, as shown in FIG. (Period) Within Tcyc, a voltage based on the compensation voltage Vpth and the non-light emitting display voltage Vzero (corresponding to the above-mentioned gradation effective voltage Vreal), for example, the compensation voltage Vpth and the non-light emitting display voltage Vzero is added to the display pixel PX The summed voltage is applied as the gradation designation voltage Vdata (0) and held between the gate and the source of the light emission driving thin film transistor Tr13 provided in the light emission driving circuit DC (at both ends of the capacitor Cs) ( A discharge operation period Twrt for setting the gate-source voltage Vgs of the thin film transistor Tr13 to 0 V and the organic EL element OEL are discharged by discharging almost all of the remaining charge. Not operated is set to include a (non-light emitting operation is allowed) light emitting operation period Tem, the (Tcyc ≧ Twrt + Tem).

  That is, in the writing operation period Twrt, as shown in FIG. 12, from the display drive device 100 (gradation voltage generation unit 130), for example, as in the drive control operation when the gradation display operation described above is performed, for example, The low potential supply voltage Vsc (= Vs) and the equipotential gradation designation voltage (the sum of the compensation voltage and the non-light emitting display voltage) are displayed via the data line input / output switching unit 190 and the data line DL through the display pixel PX ( The gate-source (capacitor Cs) of the thin-film transistor Tr13 for driving light emission provided in the light-emitting driver circuit DC) is applied directly to the source terminal side (contact N12) of the thin-film transistor Tr13, and the gate- The source voltage Vgs (the potential Vc across the capacitor Cs) is set to 0V.

  In this way, almost all of the electric charge accumulated in the capacitor Cs is discharged, and the gate-source voltage Vgs of the thin film transistor Tr13 becomes a voltage value (substantially 0 V) sufficiently lower than the threshold voltage Vth13 inherent to the thin film transistor Tr13. Therefore, when the write operation period Twrt shifts to the light emission operation period Temp, the supply voltage Vsc shifts from the low potential (Vs) to the high potential (Ve), and the gate potential of the thin film transistor Tr13 (the potential of the contact N11) ) Slightly increases, as shown in FIG. 13, the thin film transistor Tr13 does not operate (holds off), the light emission drive current Iem is not supplied to the organic EL element OEL, and the light emission operation is not performed. Not performed (becomes a non-light emitting state).

  As a result, during a non-light emitting display operation, a gray scale signal (gray scale current) having a current value corresponding to the non-light emitting display data is supplied via the data line DL and connected between the gate and source of the thin film transistor Tr13. Compared to the case where almost all of the electric charge accumulated in the capacitor Cs is discharged, the time required for writing the non-light emitting display data is shortened, and the non-light emitting state (non-light emitting display operation) of the organic EL element OEL is reduced. It can be realized reliably. Therefore, in addition to the display driving operation for performing the normal gradation display described above, the display driving operation for performing the non-light emitting display is switched and controlled in accordance with the display data (luminance gradation data), so that the desired display operation can be performed. The light emission operation with the number of gradations (for example, 256 gradations) can be realized with relatively high brightness and clarity.

  In the display pixel PX according to the present embodiment, as shown in FIG. 1, an n-channel amorphous silicon thin film transistor is applied as the thin film transistors Tr11 to Tr13 provided in the light emission drive circuit DC. However, a polysilicon thin film transistor may be applied, or a p-channel amorphous silicon thin film transistor may be applied. Here, when the p-channel type is applied to all, the signal on level and off level high and low are set to be inverted.

  Here, when an amorphous silicon thin film transistor is applied as the thin film transistors Tr11 to Tr13 provided in the display pixel PX (light emission drive circuit DC), as described above, the already established amorphous silicon manufacturing technology is applied, and element characteristics ( A light emission driving circuit made of an amorphous silicon thin film transistor with uniform electron mobility can be manufactured by a relatively simple manufacturing process.

In this case, in the amorphous silicon thin film transistor, the threshold voltage fluctuation (Vth shift) due to the drive history is remarkable. However, according to the display drive device and the drive control method applied to the present invention, the display data In the writing operation, the threshold voltage (threshold voltage after fluctuating due to the Vth shift) inherent to the light emission driving thin film transistor Tr13 provided in each display pixel PX (light emission drive circuit DC) is detected, Since the voltage component corresponding to the threshold voltage is controlled so as to be applied and held together with the gradation effective voltage, it always operates regardless of the fluctuation state of the threshold voltage of the thin film transistor Tr13 in each display pixel PX. The gradation effective voltage corresponding to the display data is added to the boundary state (the state in which the fluctuating threshold voltage is compensated) and held. The organic EL element can be caused to emit light at a luminance gradation corresponding to the gradation effective voltage.

Further, in the present embodiment, as shown in FIG. 1, the circuit configuration is such that the light emission drive current generated by the light emission drive circuit DC provided in each display pixel PX flows into the organic EL element OEL that is a light emitting element. However, the present invention is not limited to this.
FIG. 14 is a main part configuration diagram showing another embodiment of a display pixel that is driven and controlled by a display driving device applied to the present invention. Here, components equivalent to those in the above-described embodiment will be described with the same or equivalent symbols.

  For example, as shown in FIG. 14, as the display pixel PX2, a thin film transistor Tr21 having a gate terminal connected to the selection line SL, a source terminal and a drain terminal connected to the contact N21 and the contact N22, and a gate terminal to the selection line SL. A thin film transistor Tr22 having a source terminal and a drain terminal connected to the data line DL and the contact N22, a gate terminal connected to the contact N21, a drain terminal connected to the contact N22, and a common voltage Vcom (for example, ground potential GND) connected to the source terminal ) Applied to the thin film transistor Tr23, a light emitting drive circuit DC2 having one end connected to the contact N21 and a common voltage Vcom applied to the other end, and a predetermined supply voltage Vsc at the anode terminal. Connected to the supply voltage line VL to be applied, the cathode terminal It can be applied to configurations with respectively connected organic EL element OEL to point N21.

  In the display pixel PX2, a voltage component corresponding to the gradation designation voltage is held between the gate and source of the light emission driving thin film transistor Tr23 (both ends of the capacitor Cs) during the write operation period, and the voltage is applied during the light emission operation period. The thin film transistor Tr23 is turned on based on the component, and a light emission drive current having a predetermined current value flows in the common voltage Vcom direction from the supply voltage line VL via the organic EL element OEL, the contact N22, and the thin film transistor Tr23 (light emission drive). The organic EL element OEL can be made to emit light with a predetermined luminance gradation corresponding to display data (gradation designation voltage).

  Furthermore, in the present embodiment, as illustrated in FIGS. 1 and 14, the circuit configuration including the three thin film transistors Tr11 to Tr13 is described as the light emission drive circuit DC provided in each display pixel PX. However, the present invention is not limited to this. That is, a light emission driving circuit corresponding to a voltage gradation designation method, using a single thin film transistor, and applying a voltage component (charge) corresponding to a gradation designation voltage applied according to display data to a capacitor or parasitic capacitance Other than the voltage holding function for holding (accumulating) and the light emission driving function for controlling the light emission driving current supplied to the light emitting element (organic EL element) based on the held voltage component. Needless to say, it may have a circuit configuration.

<Display device>
Next, a display device and a drive control method thereof according to the present invention will be described with reference to the drawings.
FIG. 15 is a schematic block diagram showing an example of the overall configuration of the display device according to the present invention, and FIG. 16 shows a display panel and its peripheral circuits (selection driver, power driver) applied to the display device according to the present embodiment. It is a schematic block diagram which shows an example. Here, components equivalent to those of the display drive device and the display pixel (light emission drive circuit) shown in the above-described embodiment are denoted by the same or equivalent reference numerals, and will be described with reference to the above-described drawings as appropriate.

  As shown in FIGS. 15 and 16, the display device 200 according to the present embodiment roughly includes a plurality of selection lines (selection lines) SL arranged in the row direction and a plurality of data lines arranged in the column direction. A plurality of display pixels PX having a light emission driving circuit DC and an organic EL element (light emitting element) OEL having a circuit configuration equivalent to the above-described embodiment are arranged in the vicinity of each intersection with the (data line) DL in n rows × m columns. (N and m are arbitrary positive integers) arranged in a matrix and connected to a selection line SL of the display panel 210, and a selection signal sequentially at a predetermined timing for each selection line SL A selection driver (selection drive unit) 220 for applying Ssel and a supply voltage line VL arranged in the row direction in parallel with each of the selection lines SL are connected to each supply voltage line VL in order for a predetermined timing. Are connected to a power source driver (power source driving unit) 230 for applying a supply voltage Vsc of a predetermined voltage level and the data line DL of the display panel 210, and each data line DL is connected during the threshold voltage detection period Tdec described above. In addition, the threshold voltage at the time of the light emission driving switching element (thin film transistor) provided in the display pixel PX (light emission drive circuit DC) of each column is detected, and each data line DL is set in the display drive period Tcyc. Through the display pixels PX of each column, the compensation voltage Vpth corresponding to the threshold voltage unique to the switching element of the display pixel PX and the gradation effective voltage Vreal corresponding to each display data (or non-light-emitting display) A data driver that supplies a voltage based on the voltage Vzero), for example, a voltage composed of the sum of the compensation voltage Vpth and the gradation effective voltage Vreal as the gradation designation voltage Vdata. A data driver) 240 and a selection control signal and a power control signal for controlling at least the operation state of the selection driver 220, the power driver 230, and the data driver 240 based on a timing signal supplied from a display signal generation circuit 260 described later. The system controller 250 that generates and outputs a data control signal (timing control signal), and display data (luminance gradation data) including a digital signal based on, for example, a video signal supplied from the outside of the display device 200 A timing signal (system clock or the like) for displaying predetermined image information on the display panel 210 is extracted or generated based on the display data and generated and supplied to the data driver 240 to the system controller 250. A display signal generation circuit 260 for supplying, It has been made.

Hereafter, each said structure is demonstrated concretely.
(Display panel)
Each display pixel PX arranged in the display panel 210 shown in FIG. 15 is applied from the selection driver 220 via the selection line SL, similarly to the display pixel shown in the above-described embodiment (see FIGS. 1 and 14). Display data based on the selection signal Ssel, the supply voltage Vsc applied from the power supply driver 230 via the supply voltage line VL, and the gradation designation voltage Vdata supplied from the data driver 240 via the data line DL. A light emission drive circuit DC that generates a light emission drive current Iem corresponding to the light emission, and an organic EL element (light emission element) that emits light with a predetermined luminance gradation according to the current value of the light emission drive current Iem supplied from the light emission drive circuit DC ) OEL. Note that, in the present embodiment, as in the above-described embodiment (see FIG. 1), the case where the organic EL element OEL is applied as the light emitting element is shown, but a predetermined luminance gradation according to the current value of the light emission driving current. Other light-emitting elements may be used as long as they are current-controlled light-emitting elements that perform a light-emitting operation.

(Selected driver)
The selection driver 220 applies an on-level (high level in the above-described display pixel) selection signal Ssel to each selection line SL based on a selection control signal supplied from the system controller 250, thereby The display pixel PX is set to the selected state. Specifically, with respect to the display pixels PX in each row, an operation of applying the selection signal Ssel to the selection line SL in the row during the threshold voltage detection period Tdec and the writing operation period Twrt in the display drive period Tcyc, By sequentially executing each row at a predetermined timing, the display pixels PX for each row are sequentially set to a selected state.

  Here, for example, as shown in FIG. 16, the selection driver 220 corresponds to the selection line SL of each row based on a selection clock signal SCK and a selection start signal SST supplied as a selection control signal from a system controller 250 described later. A known shift register 221 that sequentially outputs shift signals to be output, and an output supplied as a selection control signal from the system controller 250 by converting the shift signal output from the shift register 221 to a predetermined signal level (on level) An output circuit unit (output buffer) 222 that outputs a selection signal Ssel to each selection line SL based on the control signal SOE is provided.

(Power supply driver)
Based on the power supply control signal supplied from the system controller 250, the power supply driver 230 applies the high potential supply voltage Vsc (= Ve) to the supply voltage line VL of the row for the display pixels PX of each row only during the light emission operation period. The low-potential supply voltage Vsc (= Vs) is applied during an operation period other than the light emission operation period (the threshold voltage detection period Tdec and the writing operation period Twrt in the display drive period Tcyc).

  Here, for example, as shown in FIG. 16, the power supply driver 230 is based on the clock signal VCK and the start signal VST supplied as the power supply control signal from the system controller 250, as in the selection driver 220 described above. A known shift register 231 that sequentially outputs a shift signal corresponding to the supply voltage line VL, and an output control signal VOE that is converted into a predetermined voltage level (voltage values Ve and Vs) and is supplied as a power control signal. And an output circuit section 232 for outputting the supply voltage Vsc to each supply voltage line VL.

(Data driver)
Similar to the display driving device 100 described in the above-described embodiment, the data driver 240 includes at least the shift register / data register unit 110, the display data latch unit 120, the gradation voltage generation unit 130, and the like illustrated in FIG. , A detection voltage ADC 140, a compensation voltage DAC 150, a threshold data latch unit 160, a frame memory 170, a voltage addition unit 180, and a data line input / output switching unit 190.

  In FIG. 1, a configuration corresponding to a single display pixel PX is shown. However, in the data driver 240 according to the present embodiment, for each data line DL arranged in the column direction of the display panel 210, The data line input / output switching unit 190 is provided, and the voltage detection side switch 191 and the voltage application side switch 192 constituting the data line input / output switching unit 190 are switched and controlled based on the drive control method described above. The operation of applying either the detection voltage Vpv or the gradation designation voltage Vdata to the display pixels PX in the column simultaneously in parallel or sequentially for each column via the data lines DL, or detection An operation of measuring the voltage Vdec is selectively executed.

That is, the shift register / data register unit 110 provided in the data driver (display driving device) 240 according to the present embodiment is based on the data control signal (shift clock signal, sampling start signal) supplied from the system controller 250. The display for one row supplied from the display signal generation circuit 260 based on the output timing of the shift signal generated corresponding to the display pixel PX (or the data line DL for each column) for one row. Capture data sequentially.
Based on the data control signal (data latch signal), the display data latch unit 120 transfers the display data for one row taken in by the shift register / data register unit 110, and displays the data for each display pixel PX in each column. Retained.

  The gradation voltage generation unit 130 generates the gradation effective voltage Vreal having a voltage value corresponding to the display data or the non-light emitting display voltage Vzero based on each display data held in the display data latch unit 120. And output to the voltage adder 180.

  Specifically, in the case where the display data is gradation display data for performing normal gradation display accompanied by the light emission operation of the organic EL element (light emitting element) OEL, for example, based on the gradation reference voltage, The analog data is converted into an analog signal voltage having a voltage value corresponding to the display data (digital-analog conversion processing), and is output to the voltage adding unit 180 as the gradation designation voltage Vdata, while the display data is converted into an organic EL element (light emitting element). ) In the case of non-light emitting display data not accompanied by the OEL light emitting operation, a predetermined non-light emitting display voltage Vzero is output to the voltage adding unit 180.

  Note that the non-light emitting display voltage Vzero is, as shown in the drive control method (non-light emitting display operation) described above, the gradation designation voltage Vdata (0) generated by the summation with the compensation voltage Vpth in the voltage adding unit 180 described later. ) Sufficiently discharges the electric charge accumulated between the gate and the source (capacitor Cs) of the light emission driving switching element (thin film transistor Tr13) provided in the light emission driving circuit DC constituting the display pixel PX. Therefore, it is necessary to set the gate-source voltage Vgs (the potential Vc across the capacitor Cs) to at least the threshold voltage Vth13 inherent to the thin film transistor Tr13, preferably 0V (or approximate to 0V). It is set to an arbitrary voltage value. Here, the non-light emitting display voltage Vzero and the gradation reference voltage for generating the gradation current Idata are supplied from, for example, power supply means (not shown).

  The detection voltage ADC 140 is used for each row set in the selected state in the threshold voltage detection operation prior to the writing operation of the display data (gradation designation voltage) to the display pixels PX of each row in the display panel 210 and the light emission operation. The threshold voltage at the time of execution of the threshold voltage detection operation (or the threshold voltage) of the light emission driving switching element (thin film transistor Tr13) provided in the column display pixel PX (light emission drive circuit DC). The voltage component corresponding to) is simultaneously measured in parallel as the detection voltage Vdec via each data line DL, or sequentially measured, and converted into threshold detection data consisting of digital signal voltage, and the threshold data latch Output to the unit 160.

  In the threshold voltage detection operation, the compensation voltage DAC 150 is applied to the display pixels PX (the light emission driving switching elements provided in the light emission drive circuit DC) in each column of the row set in the selected state. The voltage Vpv is output simultaneously or sequentially via each data line DL.

  Further, the compensation voltage DAC 150 is provided to the display pixels PX of the respective columns of the rows set to the selected state in the writing operation of the display data (gradation designation voltage) to the display pixels PX of the respective rows in the display panel 210. A compensation voltage Vpth is generated based on threshold compensation data for compensating a threshold voltage specific to the switching element, and is output to the voltage adder 180.

  In the threshold voltage detection operation, the threshold data latch unit 160 converts the threshold detection data converted and generated by the detection voltage ADC 140 for each display pixel PX in each column of the row set in the selected state. Then, the shift register / data register unit 110 takes out the threshold detection data for one row and sequentially transfers it to the frame memory 170.

  In addition, the threshold data latch unit 160 sequentially extracts from the frame memory 170 by the shift register / data register unit 110 for each display pixel PX in each column of the row set in the selected state in the above write operation. The threshold compensation data corresponding to the threshold detection data is fetched and held, and transferred to the compensation voltage DAC 150 for each column.

  Then, in the writing operation, the voltage adding unit 180 applies the grayscale effective voltage Vreal generated by the grayscale voltage generating unit 130 for the display pixel PX in each column of the row set to the selected state, or none. The light emission display voltage Vzero and the compensation voltage Vpth generated by the compensation voltage DAC 150 are added together, and the total voltage component is simultaneously or in parallel via the data line DL of each column or sequentially. Output to the display pixel PX.

(System controller)
The system controller 250 generates and outputs a selection control signal, a power supply control signal, and a data control signal for controlling the operation state to each of the selection driver 220, the power supply driver 230, and the data driver 240, thereby outputting each driver. By operating at a predetermined timing, a selection signal Ssel having a predetermined voltage level, a supply voltage Vsc, and a gradation designation voltage Vdata (or a non-light emitting display voltage Vzero) are generated and output, and each display pixel PX (light emission driving) is generated. Predetermined voltage information based on the video signal by executing a threshold voltage detection operation (voltage application operation, voltage convergence operation, voltage reading operation) and display drive operation (writing operation, light emission operation) in the circuit DC). Is displayed on the display panel 210.

(Display signal generation circuit)
For example, the display signal generation circuit 260 extracts a luminance gradation signal component from a video signal supplied from the outside of the display device 200, and converts the luminance gradation signal component from a digital signal for each row of the display panel 210. Is supplied to the shift register / data register unit of the data driver 240 as display data (luminance gradation data). Here, when the video signal includes a timing signal component that defines the display timing of the image information, such as a television broadcast signal (composite video signal), the display signal generation circuit 260 displays the luminance gradation signal component. In addition to the function of extracting the timing signal component, the timing signal component may be extracted and supplied to the system controller 250. In this case, the system controller 250 generates control signals to be individually supplied to the selection driver 220, the power supply driver 230, and the data driver 240 based on the timing signal supplied from the display signal generation circuit 260. .

  Note that the display device according to the present embodiment has a configuration in which the selection driver 220 connected to the selection line SL and the power supply driver 230 connected to the supply voltage line VL are individually provided around the display panel 210. As shown in the drive control method (see FIGS. 7 and 11) of the display drive device (corresponding to the data driver 240) described above, the display pixels PX in a specific row (from the selection driver 220) Since the selection signal Ssel applied to the selection line SL and the supply voltage Vsc applied to the supply voltage line VL (from the power supply driver 230) are set so that the signal levels are in an inverted relationship with each other, the display panel When the display drive operation (particularly, the light emission operation) is performed for each display pixel PX arranged in 210 independently in a row unit (specifically, a display device described later). In the case of the first example of the driving control method 200, the signal level of the selection signal Ssel generated by the selection driver 220 is inverted (level inversion processing), and further, the level conversion is performed so as to have a predetermined voltage level. Thus (level conversion processing), the configuration in which the power supply driver 230 is eliminated can be applied by applying the voltage to the supply voltage line VL of the row.

<Display Device Driving Control Method (Part 1)>
Next, a drive control method (drive control operation) in the display device according to the present embodiment will be described.
FIG. 17 is a timing chart schematically showing a first example of the drive control method for the display device according to the present embodiment. Here, the description of the drive control method (see FIGS. 2 and 7) equivalent to that in the display drive device and the display pixel (light emission drive circuit) shown in the above-described embodiment will be simplified. In the present embodiment, for convenience of explanation, it is assumed that display pixels of 12 rows (n = 12; 1st to 12th rows) are arranged on the display panel for convenience. To do.

  A first example of the drive control operation of the display device 200 according to the present embodiment is schematically shown in FIG. 17, first, a display drive operation for displaying image information on the display panel 210 (FIGS. 2 and 7). Prior to the display driving period), for all the display pixels PX arranged in the display panel 210, the light emission state of the organic EL element (light emitting element) OEL is changed in the light emission driving circuit DC provided in each display pixel PX. Executes a threshold voltage detection operation (threshold voltage detection period Tdec) for detecting a threshold voltage (or a voltage component corresponding to the threshold voltage) of a switching element (thin film transistor) for driving light emission to be controlled. Then, within one frame period Tfr (about 16.7 msec), the threshold voltage of the switching element is applied to the display pixel PX (light emission drive circuit DC) for each row of the display panel 210. A voltage component composed of the compensation voltage and the gradation effective voltage corresponding to the display data is held (display data is written by compensating the threshold voltage), and the display pixels PX (organic EL elements OEL) in each row are displayed as described above. A display driving operation (display driving period Tcyc) in which light emission is performed at a luminance gradation corresponding to data (gradation effective voltage) is sequentially repeated for all rows, and image information for one screen of the display panel 210 is displayed.

  Here, the threshold voltage detection operation (threshold voltage detection period Tdec) is a predetermined value for the display pixel PX (light emission drive circuit DC) for each row of the display panel 210, as in the above-described embodiment. Voltage application operation for applying the detection voltage Vpv (voltage application period Tpv), and voltage convergence for converging the voltage component based on the detection voltage Vpv to the threshold voltage at the detection time of each switching element (thin film transistor Tr13). Operation (voltage convergence period Tcv) and threshold voltage Vth13 after voltage convergence in each display pixel PX is measured (read) and stored as threshold detection data for each display pixel PX (voltage reading) A series of drive control consisting of (period) is sequentially executed at a predetermined timing for each row.

  Here, in the timing chart shown in FIG. 17, hatched portions indicated by hatching in each row of the threshold voltage detection period Tdec are the voltage application operation, the voltage convergence operation, and the voltage reading operation described in the above-described embodiment, respectively. A series of threshold voltage detection operations consisting of the above is represented, and the threshold voltage detection operations for each row are sequentially executed at different timings so that they do not overlap in time.

  As for the display driving operation (display driving period Tcyc), the display pixel PX (light emission driving circuit DC) for each row of the display panel 210 is also applied to the display panel 210 within one frame period Tfr as in the above-described embodiment. The threshold value of each display pixel PX is detected based on the threshold detection data (threshold compensation data) detected for each display pixel PX (light emission driving switching element) by the threshold voltage detection operation. A compensation voltage Vpth for compensating the voltage is generated, and a voltage component based on the compensation voltage Vpth and the gradation effective voltage Vreal according to the display data, for example, a voltage component that is a sum of the compensation voltage Vpth and the gradation effective voltage Vreal ( Each display pixel P has a luminance gradation corresponding to the display data (gradation effective voltage) at a predetermined timing and a writing operation (writing operation period Twrt) for writing gradation designation voltages VIdata and Vdata (0)). Light emitting operation for emitting the (organic EL element OEL) and (light emitting operation period Tem), a series of drive control consisting sequentially performed at predetermined timing for each row.

  Here, in the timing chart shown in FIG. 17, the hatched portions indicated by the cross mesh in each row of the display drive period Tcyc each represent the display data writing operation shown in the above-described embodiment. In the present embodiment, the writing operation for each row is sequentially executed at different timings so as not to overlap in time, and the light emitting operation is executed sequentially from the display pixel PX of the row for which the writing operation has been completed. That is, among the display driving operations for each row, only the light emitting operation is executed so as to overlap each other in time (partially in parallel).

Hereinafter, the first example of the display driving operation according to the present embodiment will be described in more detail.
As shown in FIG. 17, in the writing operation period Twrt (displayed by cross mesh in the figure) of the display driving operation (display driving period Tcyc), a specific row (for example, i row) of the display panel 210 from the selection driver 220 is displayed. As shown in FIGS. 7 and 11, by applying an on-level (high level) selection signal Ssel to the selection line SL of the first; 1 ≦ i ≦ 12), the display pixels PX in the i-th row Set to the selected state. In the write operation period Twrt, the low-potential supply voltage Vsc (= Vs) is applied from the power supply driver 230 to the i-th supply voltage line VL.

  In synchronization with this timing (hereinafter referred to as “selection timing” for the sake of convenience), a switching element provided in each display pixel PX (light emission drive circuit DC) from a compensation voltage DAC 150 provided in the data driver 240. An individual compensation voltage Vpth for compensating the threshold voltage of the (thin film transistor) is generated and output to the voltage adder 180. On the other hand, the grayscale voltage generator 130 supplies each display pixel PX (light emission drive circuit DC). The grayscale effective voltage Vreal (or the non-light emitting display voltage Vzero) corresponding to the display data is generated and output to the voltage adding unit 180.

  As a result, the voltage adding unit 180 adds (adds) the compensation voltage Vpth and the grayscale effective voltage Vreal (or the non-light emitting display voltage Vzero), and the voltage component that is the sum total is added to the grayscale specified voltage Vdata (or , The gradation designation voltage Vdata (0)) is applied to each data line DL, whereby the control terminal of the switching element of each display pixel PX in the i row (specifically, the gate-source of the thin film transistor Tr13) A voltage component corresponding to a threshold voltage specific to the switching element (thin film transistor Tr13) and a voltage component corresponding to the gradation effective voltage (display data) are held between terminals (both ends of the capacitor Cs) (charge is accumulated). Or discharge).

  Here, as in the drive control method described above, the display data supplied from the display signal generation circuit 260 to the data driver 240 is gray scale display data (other than 0 bits) accompanied by the light emitting operation of the organic EL element (light emitting element) OEL. Gradation value; gradation display operation), the gradation voltage generation unit 130 generates a gradation effective voltage Vreal corresponding to the display data, while the display data is converted into an organic EL element (light emitting element). ) In the case of non-light-emitting display data not accompanied by OEL light-emitting operation (0-bit gradation value; non-light-emitting display operation)), a predetermined non-light-emitting display voltage Vzero is generated by the gradation voltage generation unit 130.

  Therefore, in the display pixel PX to which the voltage component (Vdata) including the gradation effective voltage Vreal is supplied as the gradation designation voltage, a threshold specific to the display pixel PX (between the gate and the source of the thin film transistor for light emission driving). In addition to the voltage component corresponding to the value voltage (Vth13), a voltage component based on the gradation effective voltage Vreal is added and charged.

  Further, in the display pixel PX to which the voltage component (Vdata (0)) including the non-light emitting display voltage Vzero is supplied as the gradation designation voltage, the voltage component corresponding to the threshold voltage (Vth13) unique to the display pixel PX. Almost all voltage components including (charge) are discharged, and as a result, a voltage (0 V) corresponding to the non-light emitting display data is set in the switching element for driving light emission (between the gate and the source of the thin film transistor). become.

  Next, as shown in FIG. 17, in the light emission operation period Tem (indicated by dot hatching in the figure) of the display drive operation (display drive period Tcyc), as shown in FIGS. By applying an off level (low level) selection signal Ssel to the selection line SL of the i row, each display pixel PX of the i row is set to a non-selection state. Further, the application of the gradation designation voltage to each data line DL from the gradation voltage generator 130 provided in the data driver 240 is cut off.

  In synchronism with this timing, a high-potential supply voltage Vsc (= Ve) is applied from the power supply driver 230 to the supply voltage line VL of the i row, whereby each display pixel PX of the i row. A light emission drive current Iem corresponding to display data (gradation effective voltage) is supplied to the organic EL element OEL based on a voltage component charged between the gate and the source of the light emission drive thin film transistor, and a predetermined luminance level is obtained. The light emission operation or the non-light emission operation is performed at the key.

  Here, when the gradation designation voltage written in each display pixel PX is based on gradation display data (gradation value other than 0 bit) accompanied by the light emitting operation of the organic EL element OEL, the organic EL element OEL is applied. A light emission driving current Iem having a current value corresponding to the gradation effective voltage is supplied, and the organic EL element OEL emits light (gradation display operation) at a predetermined luminance gradation corresponding to the display data. When the modulation signal is based on non-light emitting display data (0-bit gradation value) that does not involve the light emission operation of the organic EL element OEL, the light emission drive current Iem is not supplied to the organic EL element OEL, and the light emission operation is performed. Not performed (non-light emitting display operation; black display operation).

  Such a light emission operation (or no light emission operation) is started in synchronization with the end timing of the write operation (immediately after the end) in the display pixel PX of the i row, and the next write operation is performed for the i row. For example, one frame period Tfr is continuously executed until the operation start timing (immediately before the start).

  In addition, in synchronization with the end timing of the writing operation for the i-th display pixel PX (from immediately after the end), the same writing operation is started for the adjacent (i + 1) -th display pixel PX. Then, in synchronization with the end timing of the write operation (immediately after the end), the light emission operation for the (i + 1) row is started.

  As a result, as shown in FIG. 17, within one frame period Tfr, display data (display data (PX) for each row of the display panel 210 is displayed on each display pixel PX by writing operation) The operation of charging an appropriate voltage component according to the gradation effective voltage) is executed sequentially at different timings so that the rows do not overlap each other in time, and the operation of the row where the writing operation is completed A drive control operation is executed in which a light emission operation (or no light emission operation) is sequentially performed from the display pixels PX at a predetermined luminance gradation so as to partially overlap each other in time.

  Thus, according to the display device and the drive control method thereof according to the present embodiment, the display drive device and the display pixel corresponding to the above-described drive control method of the current gradation designation method are applied to the data driver and the display panel, respectively. Thus, in a normal gradation display operation (other than a non-light emission display operation), the light emitting element (organic EL element) is based on the voltage value of the gradation effective voltage corresponding to the display data. ) Can be controlled, and a voltage component corresponding to a threshold voltage specific to a light emission driving switching element provided in each display pixel (light emission drive circuit) can be represented by display data (level). And the threshold voltage after the fluctuation due to the Vth shift in each display pixel. Regardless of the voltage), it is possible to set the state where the gradation effective voltage according to the display data is added and held in the state that always becomes the operation boundary (the state in which the threshold voltage is compensated). Display data can be displayed stably over a long period of time without being affected by variations in element characteristics (threshold voltage) of the light emission driving switching element (thin film transistor) provided in the display pixel (light emission driving circuit) or changes with time. The light emitting element (organic EL element) can be operated to emit light at a luminance gradation corresponding to the above.

  Further, according to the display device and the drive control method thereof according to the present embodiment, in the writing operation of the display data to each display pixel, it is inherent to the light emission driving switching element provided in each display pixel (light emission drive circuit). Switching element (thin film transistor) for driving light emission provided in each display pixel with a gradation designation voltage based on a voltage component corresponding to the threshold voltage of the pixel and a voltage component corresponding to display data (gradation effective voltage) It is possible to apply a voltage gradation designation type drive control method in which the voltage is directly applied to the voltage and held.

  Therefore, compared to the drive control method of the current gradation designation method, the voltage component according to the display data can be written quickly and appropriately, so that the occurrence of insufficient writing in each display pixel can be suppressed, Further, since it is not affected by the Vth shift of the light emission driving switching element (thin film transistor) provided in each display pixel, desired image information can be obtained over a long period of time with an appropriate luminance gradation according to the video signal. It can be displayed well.

  Further, during non-light-emitting display, light is emitted by supplying a gradation designation voltage Vdata (0) including a predetermined non-light-emitting display voltage Vzero corresponding to display data (0-bit gradation value) to each display pixel. Since almost all voltage components held in the driving switching element (between the gate and source of the thin film transistor) can be discharged quickly, the supply of the light emission driving current to the light emitting element (organic EL element) is reliably cut off. Thus, a non-light emitting display operation can be stably realized.

  Furthermore, according to the display device and the drive control method thereof according to the present embodiment, in each row of the display panel, in one frame period other than the write operation period, until the start timing of the next write operation period, Since the drive control is performed so that the light emission operation continues, the light emission time of each display pixel (light emitting element) can be set sufficiently long, and the image information can be displayed with high light emission luminance. In other words, this means that image information can be displayed with sufficient luminance even when the light emission luminance of each display pixel is reduced, and therefore, power consumption for displaying image information is reduced. be able to.

Next, a second example of the drive control method applicable to the display device according to the present embodiment will be described with reference to the drawings.
FIG. 18 is a timing chart schematically showing a second example of the drive control method for the display device according to the present embodiment. Here, the description of the drive control method equivalent to the above-described first example (see FIG. 17) is simplified. In addition, each hatching portion in the drawing shows an operation state equivalent to that of the first example described above. Moreover, FIG. 19 is a principal part block diagram which shows an example of the display apparatus for implement | achieving the 2nd example of the drive control method of the display apparatus which concerns on this embodiment. Here, the same components as those of the display device described in the above-described embodiment will be described with the same reference numerals.

  As shown in FIG. 18, in the second example of the drive control operation of the display device 200 according to the present embodiment, first, as in the first example described above, all the display pixels PX arranged in the display panel 210. Accordingly, the threshold voltage detection operation is sequentially executed for each row at a predetermined timing, and after the threshold voltage detection period Tdec ends, the display pixels PX (for each row of the display panel 210 within one frame period Tfr). The operation of writing the gradation designation voltage composed of the compensation voltage and the gradation effective voltage to the light emission drive circuit DC) is sequentially repeated for all the rows, and the display pixels PX (groups of rows PX (grouped in advance) at a predetermined timing). By executing a display driving operation (display driving period Tcyc) in which the organic EL elements OEL) simultaneously emit light at a luminance gradation corresponding to the display data (gradation effective voltage), the display panel Image information 10 one screen is displayed.

  Here, in the second example of the display drive operation according to the present embodiment, specifically, first, all the display pixels PX arranged in the display panel 210 are grouped in advance for each of a plurality of rows. For example, as shown in FIG. 18, 12 rows of display pixels PX constituting the display panel 210 are arranged in 4 rows such as the 1st to 4th rows, the 5th to 8th rows, and the 9th to 12th rows adjacent to each other. Minute display pixels PX are grouped as a set.

  Then, within one frame period Tfr, the above writing operation is sequentially performed at different timings on the display pixels PX (light emission drive circuit DC) for each row of the display panel 210. Next, in each of the above groups, the light emission operation is performed for the group in which the writing operation to the display pixels PX of all the rows included in the group is completed.

  For example, in a group in which the display pixels PX in the first to fourth rows are set as one set, the writing operation is executed in order from the display pixels PX in the first row, and the writing operation is performed on the display pixels PX in the fourth row. At the end timing, based on the display data (gradation effective voltage) written to each display pixel PX, the display pixels PX for the four rows of the group simultaneously emit light. This light emission operation is continued until the next writing operation is started for the display pixels PX in the first row.

  In addition, at the timing when the writing operation is completed for the display pixels PX in the fourth row, the writing operations are sequentially performed from the display pixels PX in the fifth row in a group including the display pixels PX in the fifth to eighth rows as a set. The action is executed. Thereafter, the same operation is repeatedly executed until the writing operation is completed for the display pixels PX in the 12th row of the next group.

  In this way, the writing operation is sequentially executed for each row at a predetermined timing, and for each preset group, when the writing operation is completed on the display pixels PX of all the rows included in the group, Drive control is performed so that all the display pixels PX of the group are caused to emit light at the same time. Therefore, in the display driving operation according to the second example, during the period in which the writing operation is being performed on the display pixels PX in other rows of the same group, all the display pixels in the group are not present. Control is performed so that the light emission operation is performed and the non-light emission display state (black display state) is set.

  For example, as shown in FIGS. 7 and 11, such a display driving operation is performed by supplying a low potential applied to the supply voltage line VL of the row by the power supply driver 230 in the writing operation. The voltage Vsc (= Vs) is continuously applied during the period in which the writing operation is performed on the display pixels PX in the rows included in the same group, and the writing operation for all the rows included in the group is completed. After that, it can be realized by controlling so that the supply voltage Vsc (= Ve) having a high potential is applied to the supply voltage lines VL of all the rows in the group.

  Further, the same drive control is performed by branching a single supply voltage line VL, for example, as shown in FIG. 19 so that a single supply voltage Vsc is simultaneously applied to each group. A configuration in which the display pixels PX in the rows (or the 5th to 8th rows and the 9th to 12th rows) are connected in common is applied, and the single supply voltage Vsc applied from the power supply driver 230 is in the same group. It can also be realized by being applied to the display pixels PX in all the included rows. Also in this embodiment, as in the case shown in FIG. 16, individual selection lines SL are provided for each row of the display panel 210, and individual selection signals Ssel are applied from the selection driver 220 at different timings. The

  Therefore, according to the drive control method (display drive operation) of such a display device, it is possible to obtain the same operation effect as the drive control method according to the first example described above, and display of each row in the same group. During the period in which the writing operation is performed on the pixels, the light emitting operation of the display pixels (light emitting elements) is not performed, and the pixel can be set to the non-light emitting state (black display state).

  Here, in the timing chart shown in FIG. 18, the 12 rows of display pixels PX constituting the display panel 210 are grouped into three groups, and the light emission operation is executed simultaneously at different timings for each group. Therefore, the ratio (black insertion rate) of the black display period by the non-light emission operation in one frame period Tfr can be set to approximately 33%. Here, in order to visually recognize a moving image clearly without blurring or blurring in human vision, it is generally a guideline that the black insertion rate is approximately 30% or more. Therefore, a display device having a good display image quality can be realized.

Next, a third example of the drive control method applicable to the display device according to the present embodiment will be described with reference to the drawings.
FIG. 20 is a timing chart schematically showing a third example of the drive control method for the display device according to the present embodiment. Here, the description of the drive control method equivalent to the above-described second example (see FIG. 18) is simplified.

  As shown in FIG. 20, the third example of the drive control operation of the display device 200 according to the present embodiment is arranged on the display panel 210 prior to the display drive operation, as in the second example described above. For all the display pixels PX, the threshold voltage detection operation is sequentially performed for each row at a predetermined timing, and then, within one frame period Tfr, the display pixels PX are arranged in the display panel 210 and are not adjacent to each other. In each group, the display driving operation for sequentially executing the above writing operation at different timings is sequentially executed for each group on the display pixels PX in each row included in the group.

  Here, in the display driving operation according to the present embodiment, specifically, all the display pixels PX arranged in the display panel 210 are, for example, arranged in 12 rows constituting the display panel 210 as shown in FIG. Display pixels PX, a set of four rows of display pixels PX, such as rows 1, 4, 7, 10, 2, 5, 8, 11, 11, 3, 6, 9, 12 Divided into three groups.

  For example, in the group including the display pixels PX in the first, fourth, seventh and tenth rows as a set, the writing operation is executed in order from the display pixel PX in the first row, and the display pixels PX in the tenth row are written. Based on the display data (gradation signal) written in each display pixel PX, the display pixels PX for the four rows in the group simultaneously emit light at the timing when the loading operation is completed. This light emission operation is continued until the next writing operation is started for the display pixels PX in the first row.

  In addition, at the timing when the writing operation is completed for the display pixel PX on the 10th row, in the group including the display pixels PX on the 2nd, 5th, 8th, and 11th rows, the display pixels PX on the 2nd row are sequentially arranged. The above writing operation is executed. Thereafter, the same operation is repeatedly executed until the writing operation is completed for the display pixels PX in the 12th row of the next group.

  As described above, the writing operation is sequentially executed at a predetermined timing for each row of each group, and when the writing operation is completed on the display pixels PX of all the rows included in the group, all of the groups in the group are performed. The display pixels PX are driven and controlled so as to simultaneously emit light. Therefore, also in the display driving operation according to the third example, during the period in which the writing operation is performed on the display pixels PX in other rows of the same group, as in the second example described above. All display pixels in the group are set to a non-light emitting display state (black display state).

  Further, like the second example described above, such a display drive operation is performed, for example, during the period in which the write operation is being performed on the display pixels PX in other rows of the same group. The supply voltage Vsc applied to the supply voltage line VL of each row in the group is held at a low potential (Vs), and after the writing operation to the display pixels PX in all rows of the same group is completed, the group Can be realized by applying a high potential supply voltage Vsc (= Ve) to the supply voltage lines VL of all the rows included in. As in the second example (see FIG. 19) described above, the supply voltage line VL is applied so that the single supply voltage Vsc is applied to the display pixels PX in all rows included in each group. A configuration may be applied in which these are branched and arranged.

  Therefore, according to the drive control method (display drive operation) of such a display device, similarly to the drive control method according to the second example described above, a plurality of 12 rows of display pixels PX constituting the display panel 210 are provided. The group is divided into groups and controlled so that the light emission operation is executed simultaneously at different timings for each group. Therefore, the non-light emission operation (black display operation) is executed for a predetermined period during one frame period Tfr. . In particular, in the present drive control method, the ratio of black display period (black insertion rate) by the non-light emitting operation can be set to approximately 33%, so that blur and blur of moving images are suppressed and sharpness is improved. A display device can be realized.

  In the drive control methods according to the second and third examples described above, the case where the display pixels PX constituting the display panel 210 are grouped into three groups has been described, but the present invention is limited to this. Needless to say, for example, the number of groups may be appropriately increased or decreased.

Below, the modification of the drive control method which concerns on the 2nd, 3rd example mentioned above is shown.
FIG. 21 is a timing chart schematically showing a modification (No. 1) of the second example of the drive control method for the display device according to the present embodiment, and FIG. 22 is a display according to the present embodiment. 6 is a timing chart schematically showing a modification (No. 1) of the third example of the drive control method of the apparatus. FIG. 23 is a timing chart schematically showing a modification (No. 2) of the second example of the drive control method for the display device according to the present embodiment, and FIG. 12 is a timing chart schematically showing a modification (No. 2) of the third example of the drive control method of the display device.

  In the modification (part 1) of the drive control method for the display device according to the second and third examples described above, for example, as shown in FIGS. 21 and 22, the display pixels PX constituting the display panel 210 are Divided into 4 groups (4 groups of 1st to 3rd lines, 4th to 6th lines, 7th to 9th lines, 10th to 12th lines in FIG. 21, 1st, 5th, 9th lines, 2 , 6, 10th row, 3rd, 7th, 11th row, 4th, 8th, and 12th row), the light emission operation is controlled at different timings for each group. In this case, the ratio (black insertion rate) of the black display period due to the non-light emission operation in one frame period Tfr is 25%, which is slightly less than 30%, which is a guideline for preventing the blurring and blurring of the moving image as described above. Thus, a display device having a relatively good display image quality can be realized.

  Further, in the modification (No. 2) of the drive control method for the display device according to the second and third examples described above, for example, as shown in FIGS. 23 and 24, the display pixel PX constituting the display panel 210 is displayed. Are divided into two groups (in FIG. 23, 2 groups in the 1st to 6th rows and 7th to 12th rows, in FIG. 24, 2 groups in the odd and even rows) at different timings for each group. Control to execute the light emission operation all at once. In this case, the ratio (black insertion rate) of the black display period due to the non-light emission operation in one frame period Tfr is 50%, which exceeds 30%, which is a guideline for preventing the above-described blur and blur of moving images from being visually recognized. Since the light emission operation period is only half of one frame period Tfr, the image information cannot be displayed with sufficient light emission luminance. Thus, by appropriately increasing the light emission luminance of each display pixel, the image information can be displayed with sufficient luminance and good display image quality.

Next, a fourth example of the drive control method applicable to the display device according to the present embodiment will be described with reference to the drawings.
FIG. 25 is a timing chart schematically showing a fourth example of the drive control method for the display device according to the present embodiment. Here, the description of the drive control method equivalent to the above-described first to third examples (see FIGS. 17 to 24) is simplified. FIG. 26 is a main part configuration diagram showing an example of a display device for realizing a fourth example of the display device drive control method according to the present embodiment. Here, the same components as those of the display device described in the above-described embodiment will be described with the same reference numerals.

  As shown in FIG. 25, the fourth example of the drive control operation of the display device 200 according to the present embodiment is performed on the display panel 210 prior to the display drive operation, as in the first to third examples described above. For all the display pixels PX arranged, the threshold voltage detection operation is sequentially executed for each row at a predetermined timing, and then in the first half of one frame period Tfr (for example, a half period of one frame period Tfr). The writing operation is sequentially performed on the display pixels PX in each row arranged in the display panel 210 at different timings, and the latter half of one frame period Tfr (for example, a period half of one frame period Tfr). ), A display driving operation is performed for causing the display pixels PX in all rows arranged on the display panel 210 to perform a light emission operation at a luminance gradation according to display data all at once.

  In this way, when the writing operation is completed on the display pixels PX in all rows, the drive control is performed so that all the display pixels PX emit light all at once, so that the writing operation is performed. Is controlled so that no light emission operation is performed in any row of display pixels PX, and all the display pixels PX perform a non-light emission display operation (black display operation).

  Such a display driving operation is performed, for example, by applying the supply voltage Vsc applied to the supply voltage lines VL of all the rows from the power supply driver 230 during the period in which the write operation is performed on the display pixels PX of each row. After maintaining the low potential (Vs) state and completing the writing operation on the display pixels PX in all rows, the high potential supply voltage Vsc (= Ve) is applied to the supply voltage lines VL in all rows. It can be realized by controlling to.

  Similar drive control is performed so that a single supply voltage Vsc is applied to all the display pixels PX at the same time. For example, as shown in FIG. 26, a single supply voltage line VL corresponds to all rows. A configuration in which all the display pixels PX arranged in the display panel 210 are shared and connected is applied, and a single supply voltage Vsc applied from the power supply driver 230 is applied to the display pixels PX in all rows. It can also be realized by being applied to. In this case, the configuration of the power supply driver 230 is such that a high-potential supply voltage Vsc (= Ve) and a low-potential supply voltage Vsc (= Vs) are determined at a predetermined timing based on, for example, a power supply control signal supplied from the system controller 250. Therefore, at least the shift register circuit as shown in FIG. 16 is not necessarily provided. Also in this embodiment, as in the case shown in FIG. 16, individual selection lines SL are provided for each row of the display panel 210, and individual selection signals Ssel are applied from the selection driver 220 at different timings. The

  Therefore, according to the drive control method (display drive operation) of such a display device, the display drive period (one frame period Tfr) is divided into the first half and the second half, and the display pixels in each row are sequentially written in the first half. Since the operation is executed and all display pixels are controlled to perform the light emission operation at the same time in the latter half, the ratio of the black display period (black insertion rate) by the non-light emission operation in one frame period Tfr is 50%. Although it exceeds 30%, which is a guideline that the moving image blur and blur are not visually recognized as described above, the light emission operation period is only half of one frame period Tfr, so that the image information can be displayed with sufficient light emission luminance. In addition, since the writing operation period in each row is shortened, there is a possibility that sufficient time for writing display data (grayscale signal) may not be secured. However, the emission luminance of each display pixel is increased appropriately. It is allowed, further, by increasing the current value of the gradation current, the image information with sufficient luminance, and can be displayed with good display quality.

<Display Device Drive Control Method (Part 2)>
In the display device drive control methods shown in the first to fourth examples described above, a gradation designation voltage (a voltage component based on the compensation voltage and the gradation effective voltage) is applied to the display pixels in each row arranged in the display panel. ) Is written and the threshold voltage detection operation is executed for all the display pixels arranged in the display panel prior to the display driving operation for emitting light at a predetermined luminance gradation. The drive control method according to the present invention is not limited to this, and the threshold voltage is applied during the display drive period while causing each display pixel (light emitting element) to perform a light emission operation to display desired image information. A detection operation may be executed.

Hereinafter, with respect to each of the drive control methods according to the first to fourth examples described above, a drive control operation in which a threshold voltage detection operation is performed during the display drive period (the threshold voltage detection period is not provided in advance). Will be described.
FIG. 27 is a timing chart schematically showing a fifth example of the drive control method for the display device according to the present invention. Here, the description of the drive control method equivalent to the above-described first example (see FIG. 18) is simplified.

  A fifth example of the drive control operation of the display device 200 according to the present invention is roughly arranged on the display panel 210 within one frame period (about 16.7 msec; constant operation period) as shown in FIG. For the display pixels in a specific row among the display pixels PX, the light emission drive switching element (thin film transistor; thin film transistor; which controls the light emission state of the organic EL element (light emission element) OEL in the light emission drive circuit DC provided in each display pixel PX. A threshold voltage detection operation (threshold voltage detection period Tdec) for detecting a threshold voltage (or a voltage component corresponding to the threshold voltage) of the light emission driving element), and each row of the display panel 210 For the display pixel PX (light emission drive circuit DC), a voltage component corresponding to a threshold voltage specific to the light emission drive switching element and a voltage corresponding to the display data (gradation effective voltage) A display drive operation (display drive period Tcyc) in which a gradation designation voltage based on the minute is written and the display pixel PX (organic EL element OEL) in each row is caused to emit light at a luminance gradation corresponding to the display data (gradation effective voltage). ) Is sequentially repeated for all lines, and image information for one screen of the display panel 210 is displayed.

Here, the threshold voltage detection operation (threshold voltage detection period Tdec) is performed in the same manner as the drive control method (see FIG. 2) in the display drive device described above. A series of drive control operations including a voltage application operation (voltage application period Tpv), a voltage convergence operation (voltage convergence period Tcv), and a voltage reading operation (voltage reading period) are executed on the light emission drive circuit DC). .
In particular, in the drive control operation of the display device according to the fifth example, the threshold voltage composed of the above-described series of drive controls for a specific row of display pixels PX for each frame period in successive frame periods. The detection operation is executed sequentially.

  Specifically, as shown in FIG. 27, in the display panel 210 in which 12 rows of display pixels PX are arranged, a threshold voltage detection operation is performed on the first row of display pixels PX in the first frame. After the threshold detection data is stored in the corresponding storage area of the frame memory, the above-described writing is performed for each row from the first row to the twelfth row for all the display pixels PX arranged in the display panel 210. A display drive operation including an operation and a light emission operation is sequentially executed.

  Next, in the second frame, the display drive operation (write operation) is performed for the display pixels PX in the first row, and then the threshold voltage detection operation is performed for the display pixels PX in the second row. For the display pixels PX from the second row to the twelfth row of the display panel 210, the display drive operation (write operation, light emission operation) is sequentially executed for each row.

  Next, in the third frame, the display drive operation (write operation) is performed for the display pixels PX in the first row and the second row, and then the threshold voltage detection operation is performed for the display pixels PX in the third row. Thereafter, the display driving operation (writing operation, light emitting operation) is sequentially executed for each row of the display pixels PX from the third row to the twelfth row of the display panel 210.

Similarly, the threshold voltage detection operation is sequentially repeated for the display pixels PX in the corresponding row up to the 12th frame, whereby all the display pixels PX arranged in one frame of the display panel 210 are displayed in the frame memory. Threshold data (threshold voltage) is stored.
That is, in the display device drive control method (threshold voltage detection operation) according to the present invention, the threshold voltage detection operation is executed for the display pixels PX in any row of the display panel 210 in each frame period. The latest threshold voltage is always detected (monitored) with the frame period for the number of rows of the display panel 210 as one cycle.

  As for the display drive operation (display drive period Tcyc), as shown in FIG. 27, as in the drive control method for the display device according to the first example (see FIG. 17), A series of drive control including a writing operation (writing operation period Twrt) and a light emitting operation (light emitting operation period Tem) is performed on the display pixels PX (light emission driving circuit DC) for each row of the display panel 210. Each row is sequentially executed at a predetermined timing.

  In particular, in the drive control operation of the display device according to the fifth example, the threshold voltage detection operation is performed for the display pixels PX in a specific row within one frame period, and the threshold voltage detection is performed. The operation and the writing operation for each row are sequentially executed at different timings so as not to temporally overlap each other, and the light emitting operation is executed sequentially from the display pixel PX of the row where the writing operation is completed. That is, among the display driving operations for each row, only the light emitting operation is executed so as to overlap each other in time (partially in parallel).

  Here, in the writing operation (writing operation period Twrt) of each row, similarly to the drive control method according to the first example described above, each display pixel PX (light emission drive circuit) is compared with the display pixel PX of each row. The gradation designation voltage Vdata based on the compensation voltage Vpth for compensating the threshold voltage of the switching element (thin film transistor) provided in the DC) and the gradation effective voltage Vreal corresponding to the display data is written. As described in the threshold voltage detection operation, the threshold voltage of the switching elements of the display pixels PX arranged in the display panel 210 is detected for a specific row of display pixels PX for each frame period. Therefore, the display pixel PX detected last time is detected and stored in the frame memory immediately after system start-up or immediately after recovery from the hibernation state. Based on 憶 threshold voltage, said compensation voltage Vpth is generated.

  Therefore, also in the drive control operation of the display device according to the fifth example, in the display pixel PX to which the gradation designation voltage Vdata is supplied, each display pixel PX in the row (between the gate and the source of the thin film transistor for driving light emission). Is added to a voltage component corresponding to the threshold voltage (Vth13) inherent to the light emission driving switching element, and the voltage component based on the gradation effective voltage Vreal is charged. In the light emission operation (light emission operation period Tem), the light emission drive current corresponding to the display data (gradation effective voltage) based on the voltage component charged in each display pixel PX (between the gate and the source of the thin film transistor for light emission drive). Iem is supplied to the organic EL element OEL, and a light emission operation or a non-light emission operation is performed at a predetermined luminance gradation.

  Such a light emitting operation (or non-light emitting operation) is started in synchronization with the end timing of the write operation in the display pixels PX of each row (immediately after the end), and the next write operation starts for the row. Until the timing (immediately before the start), for example, it is continuously executed for one frame period. Further, in synchronization with the end timing of the writing operation for the display pixels PX in each row (for example, the i-th row; 1 ≦ i ≦ 12) (immediately after the end), the display pixels in the adjacent row (i + 1-th row) A write operation is started for PX. As described above, in the row (for example, the i-th row) in which the threshold voltage detection operation (threshold detection period Tdec) is executed, the previous row (i-1th row). After the write operation for) is completed, the threshold voltage detection operation is executed for the row, and then the write operation is executed.

  Therefore, according to the drive control method (display drive operation) of such a display device, it is possible to obtain the same operational effects as those of the drive control method according to the first example described above, and each row arranged in the display panel. Prior to the writing operation of the display data to the display pixels and the light emitting operation of the light emitting elements, the threshold is set for the display pixels in any row (specific row) arranged on the display panel every frame period. Since the threshold voltage (Vth shift state) of the switching element for light emission driving at the time of execution of the value voltage detection operation can always be monitored, each of the normal display driving operations (writing operation and light emission operation) is specified. There is no need to provide a special threshold voltage detection period prior to the frame period, and the display drive operation (frame period) can be started immediately after the system is started.

  Therefore, even in the case of applying a display panel including a display pixel (light emission drive circuit) made of an amorphous silicon thin film transistor in which a Vth shift is likely to occur in a display device to which a voltage gradation designation type drive control method is applied, The influence of the Vth shift of the switching element (thin film transistor) for driving light emission provided in the display pixel can be suppressed, and writing shortage does not occur at the time of low gradation display. Desired image information can be satisfactorily displayed over a long period of time with luminance gradation.

Next, a sixth example of the drive control method in the display device according to the present invention will be described with reference to the drawings.
FIG. 28 is a timing chart schematically showing a sixth example of the display device drive control method according to the present invention, and FIG. 29 shows a seventh example of the display device drive control method according to the present invention. 2 is a timing chart schematically showing an example. Here, the description of the drive control method equivalent to the above-described second and third examples (see FIGS. 18 and 20) is simplified.

  In the sixth and seventh examples of the drive control operation of the display device 200 according to the present invention, as shown in FIG. 28 and FIG. 29, the display pixels PX arranged in the display panel 210 are arranged for a plurality of adjacent rows. Alternatively, the threshold voltages are set for the switching elements (thin film transistors) for driving light emission of the display pixels PX in a specific row in a specific group within one frame period. Threshold voltage detection operation to be detected (threshold voltage detection period Tdec), and a compensation voltage for compensating the threshold voltage for the display pixels PX for each row of the display panel 210 within one frame period A writing operation (writing operation period Twrt) for writing the gradation designation voltage Vdata based on the gradation effective voltage corresponding to the display data is sequentially repeated for all the rows, and each group has a predetermined timing. Display information for one screen of the display panel 210 by performing a display driving operation for simultaneously emitting light at a luminance gradation corresponding to display data in a plurality of rows of display pixels PX (organic EL elements OEL). Is displayed.

  Here, specifically, in the drive control operations according to the sixth and seventh examples, similarly to the drive control methods according to the second and third examples described above, the display pixels PX constituting the display panel 210 are controlled. Grouped into 3 groups (in FIG. 28, 3 groups of 1st to 4th rows, 5th to 8th rows, 9th to 12th rows, 1st, 4th, 7th, 10th rows, 2, 5th, 8th, 11th, 3rd, 6th, 9th, and 12th rows), a threshold voltage detection operation is performed for display pixels PX in a specific row in a specific group for each frame period, and each group After performing the writing operation on the display pixels PX in each row at different timings, the light emitting operation is performed on all the groups in which the writing operations to the display pixels PX in all the rows included in the group are completed. To control.

  As described above, in the drive control methods according to the sixth and seventh examples, as in the drive control method according to the fifth example described above, the threshold value for the display pixels PX in a specific row for each frame period. By sequentially repeating the voltage detection operation, the threshold voltage detection operation is performed for the display pixels PX in any row of the display panel 210 in each frame period, and the frame period corresponding to the number of rows of the display panel is 1 As a cycle, the latest threshold voltage is always detected (monitored). Further, during the period in which the threshold voltage detection operation and the write operation are performed on the display pixels PX in other rows of the same group, all the display pixels in the group do not emit light and do not emit light. Control is performed so that the light emission display state (black display state) is set.

  In addition, such a display driving operation is similar to the second and third examples described above, for example, with respect to the display pixels PX in other rows included in the same group, the threshold voltage detection operation and the writing. During the period in which the operation is being performed, the supply voltage Vsc applied from the power supply driver 230 to the supply voltage line VL of each row of the group is kept at a low potential (Vs), and the display pixels of all rows of the same group This can be realized by controlling the supply voltage Vsc (= Ve) having a high potential to be applied to the supply voltage lines VL of all the rows included in the group after the writing operation on the PX is completed. As in the second and third examples (see FIG. 19) described above, supply is performed so that a single supply voltage Vsc is applied to the display pixels PX in all rows included in each group. A configuration in which the voltage line VL is branched and disposed may be applied.

  Therefore, according to the drive control method (display drive operation) of such a display device, it is possible to obtain the same operation and effect as the drive control method according to the fifth example described above, and to display each row in the same group. During the period when the threshold voltage detection operation and the writing operation are performed on the pixel, the light emission operation of the display pixel (light emitting element) is not performed, and the non-light emission operation (black display operation) is performed. In this case, in one frame period Tfr The ratio of the black display period by the non-light emitting operation (black insertion rate) is approximately 33%, and is set to approximately 30% or more, which is a guideline for the black insertion rate for clearly viewing a moving image without blurring or blurring. Thus, a display device having a good display image quality can be realized.

  The display device drive control method according to the present invention is limited to the case where the display pixels PX constituting the display panel 210 are grouped into three groups as shown in the sixth and seventh examples. Instead of this, the number of groups may be appropriately increased or decreased as in the second and third examples described above.

  FIG. 30 is a timing chart schematically showing a modified example (No. 1) of the sixth example of the drive control method for the display device according to the present invention, and FIG. 31 shows the display device according to the present invention. 12 is a timing chart schematically showing a modification (No. 1) of the seventh example of the drive control method. FIG. 32 is a timing chart schematically showing a modification (No. 2) of the seventh example of the drive control method for the display device according to the present invention, and FIG. 33 is a display according to the present invention. 10 is a timing chart schematically showing a modification (No. 2) of the seventh example of the drive control method of the apparatus.

  In the modified example (part 1) of the drive control method for the display device according to the sixth and seventh examples described above, for example, as shown in FIGS. 30 and 31, the display pixels PX constituting the display panel 210 are Grouped into 4 groups (in FIG. 30, 4 groups of 1st to 3rd lines, 4th to 6th lines, 7th to 9th lines, 10th to 12th lines, 1st, 5th, 9th lines, 2 , 6, 10th row, 3rd, 7th, 11th row, 4th, 8th, 12th row), a threshold voltage detection operation is performed for display pixels PX in a specific row for each frame period. Then, after performing the writing operation on the display pixels PX in each row at different timings for each group, control is performed so that the light emitting operations are performed all at once. In this case, the ratio (black insertion rate) of the black display period due to the non-light emission operation in one frame period is approximately 25%, which is slightly less than 30%, which is a standard for preventing the above-described blurring and blurring of moving images from being visually recognized. Thus, a display device having a relatively good display image quality can be realized.

  Further, in the modified example (No. 2) of the drive control method of the display device according to the sixth and seventh examples described above, for example, as shown in FIGS. 32 and 33, the display pixel PX constituting the display panel 210. Are grouped into two sets (two groups in the first to sixth rows and the seventh to twelfth rows in FIG. 32, two groups in the odd and even rows in FIG. 33), and each frame period is specified. Control is performed so that the threshold voltage detection operation is performed for the display pixels PX in the row, and the writing operation is performed for the display pixels PX in each row at different timings for each group, and then the light emission operation is performed all at once.

  In this case, the ratio of the black display period by the non-light emission operation in one frame period (black insertion rate) is approximately 50%, which exceeds 30%, which is a guideline for preventing the above-described blur and blur of the moving image from being visually recognized. Since the light emission operation period is only half of one frame period, the image information cannot be displayed with sufficient light emission luminance. Thus, by appropriately increasing the light emission luminance of each display pixel, the image information can be displayed with sufficient luminance and good display image quality.

Next, an eighth example of the drive control method for the display device according to the present invention will be described with reference to the drawings.
FIG. 34 is a timing chart schematically showing an eighth example of the drive control method for the display device according to the present invention. Here, the description of the drive control method equivalent to the above-described fourth example (see FIG. 25) is simplified.

  As shown in FIG. 34, the eighth example of the drive control operation of the display device 200 according to the present invention is the first half of one frame period (for example, half of one frame period). After the threshold voltage detection operation (threshold voltage detection period Tdec) is performed on the switching elements (thin film transistors) for driving the light emission of the display pixels PX in a specific row arranged in FIG. For all the display pixels PX in all rows, the writing operation is sequentially executed for each row at different timings. The display operation is performed on the display panel 210 in the second half of one frame period (for example, a half of one frame period). By executing a display driving operation in which the display pixels PX of all the rows arranged are simultaneously light-emitted with luminance gradations according to display data, image information for one screen of the display panel 210 is displayed. It is.

  As described above, the threshold voltage detection operation is executed for the display pixels PX in a specific row for each frame period, and the drive control is performed so that all the display pixels PX are simultaneously lit in the second half of each frame period. Thus, in the first half of each frame period in which the threshold voltage detection operation and the writing operation are performed, no light emission operation is performed in any row of the display pixels PX, and all the display pixels PX are displayed in a non-light emitting display. It is controlled to operate (black display operation).

  In addition, such a display driving operation is performed in the same way as the fourth example described above, for example, during a period in which the threshold voltage detection operation and the writing operation are performed on the display pixels PX in each row. The supply voltage Vsc applied from the driver 230 to the supply voltage line VL of all rows is held at a low potential (Vs), and the threshold voltage detection operation and the write operation for the display pixels PX of all rows are completed. After that, it can be realized by controlling so as to apply a high-potential supply voltage Vsc (= Ve) to the supply voltage lines VL of all rows. As in the fourth example (see FIG. 26) described above, the supply voltage line VL is branched and arranged so that the single supply voltage Vsc is applied to the display pixels PX in all rows. A configuration that is provided may be applied.

  Therefore, according to the drive control method (display drive operation) of such a display device, each frame period is divided into two parts, the first half and the second half, as in the drive control method according to the fourth example described above. After the threshold voltage detection operation is performed on the display pixels in a specific row, the writing operation is sequentially performed on the display pixels in each row, and in the latter half, all the display pixels simultaneously perform the light emission operation. Therefore, the ratio of the black display period (black insertion ratio) by the non-light emission operation in one frame period Tfr is approximately 50%, and 30%, which is a guideline for the above-described blurring and blurring of moving images not being visually recognized. However, since the light emission operation period is only half of one frame period Tfr, the image information cannot be displayed with sufficient light emission luminance, and the write operation period in each row is shortened. Floor There is a possibility that sufficient time for writing the adjustment signal) is not secured, but by appropriately increasing the light emission luminance of each display pixel and further increasing the current value of the gradation current, the image information can be displayed with sufficient luminance, In addition, it is possible to display with good display image quality.

1 is a main part configuration diagram showing an embodiment of a display driving device applied to the present invention and a display pixel driven and controlled by the display driving device. 6 is a timing chart showing a threshold voltage detection operation in the display driving apparatus according to the embodiment. It is a conceptual diagram which shows the voltage application operation | movement in the display drive device which concerns on this embodiment. It is a conceptual diagram which shows the voltage convergence operation | movement in the display drive device which concerns on this embodiment. It is a conceptual diagram which shows the voltage reading operation | movement in the display drive device which concerns on this embodiment. FIG. 6 is a diagram illustrating an example of a drain-source current characteristic when an n-channel thin film transistor has a gate-source voltage set to a predetermined condition and a drain-source voltage is modulated. 4 is a timing chart showing a drive control method when performing a gradation display operation in the display drive device according to the present embodiment. It is a conceptual diagram which shows data write-in operation | movement in the drive control method (gradation display operation) which concerns on this embodiment. It is a conceptual diagram which shows light emission operation | movement in the drive control method (gradation display operation | movement) which concerns on this embodiment. It is a principal part block diagram which shows the other structural example of the display drive device which concerns on this embodiment. 5 is a timing chart showing an example of a drive control method when performing a non-light emitting display operation in the display drive device according to the present embodiment. It is a conceptual diagram which shows data write-in operation | movement in the drive control method (non-light emission display operation | movement) concerning this embodiment. It is a conceptual diagram which shows a non-light-emission operation | movement in the drive control method (non-light-emitting display operation) which concerns on this embodiment. It is a principal part block diagram which shows other embodiment of the display pixel which is drive-controlled by the display drive apparatus applied to this invention. It is a schematic block diagram which shows an example of the whole structure of the display apparatus which concerns on this invention. It is a schematic block diagram which shows an example of the display panel applied to the display apparatus which concerns on this embodiment, and its peripheral circuit (selection driver, power supply driver). 3 is a timing chart schematically showing a first example of a display device drive control method according to the present embodiment; 6 is a timing chart schematically showing a second example of the drive control method for the display device according to the embodiment. It is a principal part block diagram which shows an example of the display apparatus for implement | achieving the 2nd example of the drive control method of the display apparatus which concerns on this embodiment. 12 is a timing chart schematically showing a third example of the drive control method for the display device according to the embodiment. It is the timing chart which showed typically the modification (the 1) of the 2nd example of the drive control method of the display apparatus which concerns on this embodiment. 12 is a timing chart schematically showing a modification (No. 1) of the third example of the drive control method for the display device according to the embodiment. 12 is a timing chart schematically showing a modification (No. 2) of the second example of the drive control method for the display device according to the embodiment. 12 is a timing chart schematically showing a modification (No. 2) of the third example of the drive control method for the display device according to the embodiment. 10 is a timing chart schematically showing a fourth example of the display device drive control method according to the embodiment. It is a principal part block diagram which shows an example of the display apparatus for implement | achieving the 4th example of the drive control method of the display apparatus which concerns on this embodiment. It is the timing chart which showed typically the 5th example of the drive control method of the display apparatus which concerns on this invention. It is the timing chart which showed typically the 6th example of the drive control method of the display apparatus which concerns on this invention. It is the timing chart which showed typically the 7th example of the drive control method of the display apparatus which concerns on this invention. It is the timing chart which showed typically the modification (the 1) of the 6th example of the drive control method of the display apparatus which concerns on this invention. It is the timing chart which showed typically the modification (the 1) of the 7th example of the drive control method of the display apparatus which concerns on this invention. It is the timing chart which showed typically the modification (the 2) of the 7th example of the drive control method of the display apparatus which concerns on this invention. It is the timing chart which showed typically the modification (the 2) of the 7th example of the drive control method of the display apparatus which concerns on this invention. It is the timing chart which showed typically the 8th example of the drive control method of the display apparatus which concerns on this invention. It is a schematic block diagram which shows the principal part of the light emitting element type display in a prior art. It is an equivalent circuit diagram which shows the principal part structural example of the display pixel (light emission drive circuit and light emitting element) applicable to the light emitting element type display in a prior art.

Explanation of symbols

PX display pixel DC light emission drive circuit SL selection line DL data line VL supply voltage line Tr11 to Tr13 thin film transistor Cs capacitor OEL organic EL element 100 display drive device 110 shift register / data register unit 120 display data latch unit 130 gradation voltage generation unit 140 Detection voltage ADC
150 Compensation voltage DAC
160 threshold data latch unit 170 frame memory 180 voltage addition unit 190 data line input / output switching unit 200 display device 210 display panel 220 selection driver 230 power driver 240 data driver 250 system controller 260 display signal generation circuit

Claims (19)

  1. A plurality of display pixels each including a current control type light emitting element and a light emitting driving element for supplying a light emitting driving current to the light emitting element at each intersection of a plurality of selection lines and data lines arranged in a row direction and a column direction In a display device comprising a display panel in which each of the above is arranged,
    At a predetermined timing, a selection signal is sequentially applied to each display pixel in each row of the display panel via each selection line, and each display pixel in each row is set to a selected state for each predetermined selection period. A selection drive unit;
    A data driver that generates a gradation signal corresponding to a luminance gradation of display data for displaying desired image information, and supplies the gradation signal to each display pixel of the row set in the selected state;
    A power supply driver that applies, to the plurality of display pixels, one of a first voltage that sets each display pixel in a light emitting operation state and a second voltage that sets each display pixel in a non-light emitting operation state as a supply voltage;
    With
    The data driver is at least
    Threshold voltage detection means for individually detecting a threshold voltage specific to the light emission drive element of each display pixel;
    Storage means for storing threshold data corresponding to the threshold voltage detected by the threshold voltage detection means in correspondence with each display pixel;
    Compensation voltage generating means for generating a compensation voltage for compensating the threshold voltage of the light emitting drive element of each display pixel based on the threshold data stored in the storage means;
    Gradation voltage generating means for generating a gradation voltage having a predetermined voltage value for causing the light emitting element to emit light at a predetermined luminance gradation;
    A gradation signal that individually supplies a voltage component based on the gradation voltage and the compensation voltage to each display pixel in the selected row as the gradation signal through each data line. Generating means;
    Have
    The power supply driving unit applies the second voltage as the supply voltage to each display pixel in the row to which the grayscale signal is supplied over the period including the selection period and longer than the selection period. The display pixels in the row are set in the non-light emitting operation state for a period longer than the selection period , and the plurality of display pixels arranged in the display panel are divided into a plurality of groups for each of the plurality of rows. In addition, for each display pixel of each group, the display pixels included in each group are common to the display pixels of the group over a period in which any of the display pixels included in the group is set to the selected state. Applying a second voltage to set each display pixel included in the group to the non-light emitting operation state, and during a period when the display pixels included in the group are not set to the selection period, group Said applying said first voltage in common to each display pixel, a display device the display pixels included in the group and setting the light emission operation state.
  2. The data driver further comprises detection voltage applying means for individually applying a threshold detection voltage higher than the threshold voltage to the light emission drive element of the display pixel,
    After the threshold voltage detection means is applied with the threshold voltage detection voltage to the light emission drive element, and a part of the electric charge corresponding to the threshold voltage detection voltage is discharged and converged, The display device according to claim 1, wherein the voltage is individually detected as a threshold voltage of the light emission drive element.
  3. The light emission drive element provided in each of the display pixels includes a current path through which the light emission drive current flows to the light emitting element, and a control terminal for controlling a supply state of the light emission drive current,
    The detection voltage application means applies the threshold detection voltage between the control terminal of the light emission drive element and one end of the current path,
    The threshold voltage detection means detects, as the threshold voltage, a potential difference between the control terminal of the light emission drive element and one end side of the current path when no current flows in the current path. The display device according to claim 2.
  4. The threshold voltage detection means includes means for converting the threshold voltage of the light emitting drive element detected as an analog signal into a digital signal and generating the threshold data,
    The compensation voltage generating means generates the compensation voltage composed of an analog signal for compensating the threshold voltage of the light emitting drive element based on the threshold data stored as a digital signal in the storage means. The display device according to claim 2, further comprising:
  5.   The gradation voltage generating means is a non-light emitting display voltage having a predetermined voltage value for causing the light emitting element to perform a non-light emitting operation as the gradation voltage when the luminance gradation of the display data is the lowest gradation. The display device according to claim 2, further comprising a generating unit.
  6. The data driver is
    Threshold value acquisition means for individually capturing and sequentially transferring the threshold data corresponding to the threshold voltage detected from each of the display pixels;
    Data acquisition means for sequentially capturing and holding brightness gradation data for generating the gradation voltage individually for each of the display pixels;
    Further,
    The storage means individually stores the threshold data for each of the plurality of display pixels transferred from the threshold acquisition means in association with each of the plurality of display pixels,
    The gradation voltage generation means generates the gradation voltage according to the luminance gradation data for each of the plurality of display pixels held in the data acquisition means,
    The gradation signal generating means individually supplies the gradation signal composed of voltage components based on the gradation voltage and the compensation voltage to each display pixel in the row set in the selected state. The display device according to claim 2, wherein:
  7.   The data acquisition means and the threshold acquisition means share a configuration in which the luminance gradation data is sequentially and individually acquired, and a configuration in which the threshold data is individually acquired and sequentially transferred. The display device according to claim 6, wherein:
  8.   The data driver supplies at least a signal path for detecting the threshold voltage of the display pixel by the threshold voltage detection unit, and supplies the gradation signal to the display pixel by the gradation signal generation unit. 8. A signal path switching means for selectively switching control of a connection between a signal path to be transmitted and a single data line provided corresponding to the display pixel. The display device described in 1.
  9.   The data driver may be configured such that a signal path for applying the threshold detection voltage to the display pixel by the detection voltage applying unit is selectively connected to the single data line. The display device according to claim 8, wherein the display device is configured.
  10. The display device further includes a drive control unit that supplies at least a timing control signal to operate at least each of the selection drive unit, the data drive unit, and the power supply drive unit at a predetermined timing,
    The drive control unit individually supplies the gradation signal corresponding to the display data to all the display pixels arranged in the display panel by the selection driving unit and the data driving unit, and the display pixels A threshold value unique to the light emitting drive elements in a specific row of the display panel during an operation period in which the light emitting elements provided in each of the display panels are operated to emit light at a predetermined timing with a luminance gradation corresponding to the display data display device according to claim 2 to 9, characterized by having means for generating the timing control signal for detecting the voltage.
  11. The drive control unit is configured to detect the threshold voltage specific to the light emission drive element for the display pixels in different rows for each operation period by the selection drive unit and the data drive unit. The display device according to claim 10 , further comprising means for generating
  12. The drive control unit sequentially repeats the operation of detecting a threshold voltage specific to the light emission drive element for the display pixels in adjacent rows every operation period by the selection drive unit and the data drive unit. 11. The display device according to claim 10 , further comprising means for generating said timing control signal.
  13. Each of the display pixels includes a light emission driving circuit that controls a light emission operation of the light emitting element,
    The light emitting driving circuit includes at least a first current path and a first control terminal, wherein the supply voltage is applied to one end of the first current path, the other end of said first current path a transistor element connected contacts is connected between the light emitting element, and a second current path a second control terminal, said second control terminal is connected to the selection line, said second current path end the supply voltage is applied to, said first switch means of the first control terminal of said transistor element to the other end of the second current path is connected, a third current path and the third control of has a terminal, said third control terminal is connected to the selection line, said data lines to one end of the third current path is connected, the connection contact is connected to the other end of the third current path Second switch means,
    The light emission driving element is the transistor element ,
    The detection voltage applying means applies the threshold detection voltage between the first control terminal of the transistor element and the connection contact,
    The threshold voltage detection means detects a potential between the first control terminal of the transistor element and the connection contact as the threshold voltage,
    The gradation signal generation means applies a voltage component based on the gradation voltage and the compensation voltage as the gradation signal between the first control terminal of the transistor element and the connection contact. display device according to any one of claims 2 to 12, wherein the.
  14. The light emitting device, a display device according to any one of claims 1 to 13, characterized in that the organic electroluminescent device.
  15. A plurality of display pixels each including a current control type light emitting element and a light emitting driving element for supplying a light emitting driving current to the light emitting element at each intersection of a plurality of selection lines and data lines arranged in a row direction and a column direction Each of the display panels is arranged, and a selection signal is sequentially applied to the display pixels in each row of the display panel via the selection lines at a predetermined timing, and the display pixels in each row are In synchronization with the timing of setting the selected state for each selection period, the gradation signal corresponding to the luminance gradation of the display data for displaying the desired image information is set to the selected state via each data line. By supplying each display pixel in a row, each display pixel is caused to emit light with a predetermined luminance gradation, and the desired image information is displayed on the display panel. Set each display pixel to the light emitting operation state. In the drive control method of a display apparatus for applying a first voltage and supply voltage or a second voltage to be set to a non-light emitting operation state constant,
    at least,
    A threshold voltage specific to the light emission drive element provided in each of the plurality of display pixels and supplying a light emission drive current having a predetermined current value to the light emission element based on the gradation signal. A detection voltage application step for individually applying a voltage for threshold detection of a higher potential than
    A voltage after a part of the electric charge corresponding to the threshold voltage detection voltage is discharged and converged is individually detected as the threshold voltage of the light emitting drive element, and the threshold voltage is supported. Threshold voltage detection step for storing the threshold voltage data in a storage means for each display pixel;
    A compensation voltage generating step for individually generating a compensation voltage for compensating the threshold voltage of the light emitting drive element for each display pixel based on the threshold data stored in the storage unit;
    A gradation voltage generating step for individually generating gradation voltages having a predetermined voltage value for causing the light emitting element for each display pixel to emit light at a predetermined luminance gradation;
    The gradation signal composed of voltage components based on the gradation voltage and the compensation voltage is individually supplied to each display pixel in the row set in the selected state via each data line, and A data writing step of causing the light emission driving element of each display pixel to hold a voltage component based on the modulation signal;
    The light emission drive current generated based on the voltage component held in the light emission drive element of each display pixel is supplied to each of the light emission elements, and the light emission element is caused to emit light at a predetermined luminance gradation. Gradation light emission step,
    The second voltage is applied as the supply voltage to each display pixel in the row to which the grayscale signal is supplied over the period including the selection period and longer than the selection period. A non-light emitting operation step of setting a display pixel in the non-light emitting operation state over a period longer than the selection period;
    Only including,
    The non-light emission operation step further divides the plurality of display pixels arranged in the display panel into a plurality of groups for each of a plurality of rows, and the display pixels included in the groups are included in the groups. Applying the second voltage in common to the display pixels of the group over a period in which any of the display pixels is set in the selected state, the display pixels included in the group are The first voltage is applied in common to the display pixels of the group in a period in which the display pixels included in the group are set to the non-light emitting operation state and the display pixels included in the group are not set to the selection period, drive control method of a display device the step of setting the display pixels included in the group to the light emitting operation condition characterized by containing Mukoto.
  16. In the detection voltage application step and the threshold voltage detection step, at least the display pixels arranged in the display panel are individually supplied with the gradation signals, and the display is performed at a predetermined timing. 16. The display device according to claim 15 , wherein the display device is executed for the display pixels in a specific row of the display panel during a fixed operation period in which the pixels emit light at a luminance gradation corresponding to the display data. Drive control method.
  17. 17. The display device drive control method according to claim 16, wherein the detection voltage application step and the threshold voltage detection step are executed for the display pixels in different rows for each predetermined operation period.
  18. 17. The display device drive control according to claim 16, wherein the detection voltage application step and the threshold voltage detection step are sequentially executed for the display pixels in adjacent rows every fixed operation period. Method.
  19. In the data writing step, when the luminance gradation of the display data is the lowest gradation, the gradation signal including a non-light emitting display voltage having a predetermined voltage value is generated and supplied to the display pixel. the light emission drive element of the display pixel, the drive control method of a display device according to any one of claims 15 to 18, characterized in that to hold the voltage component of the following at least the threshold voltage.
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Families Citing this family (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4935979B2 (en) * 2006-08-10 2012-05-23 カシオ計算機株式会社 Display device and driving method thereof, display driving device and driving method thereof
JP5240542B2 (en) * 2006-09-25 2013-07-17 カシオ計算機株式会社 Display driving device and driving method thereof, and display device and driving method thereof
JP5240538B2 (en) * 2006-11-15 2013-07-17 カシオ計算機株式会社 Display driving device and driving method thereof, and display device and driving method thereof
JP5010949B2 (en) * 2007-03-07 2012-08-29 パナソニック液晶ディスプレイ株式会社 Organic EL display device
JP5317419B2 (en) * 2007-03-07 2013-10-16 株式会社ジャパンディスプレイ organic EL display device
JP5171807B2 (en) * 2007-03-08 2013-03-27 シャープ株式会社 Display device and driving method thereof
JP5240544B2 (en) 2007-03-30 2013-07-17 カシオ計算機株式会社 Display device and driving method thereof, display driving device and driving method thereof
JP2009128523A (en) * 2007-11-21 2009-06-11 Sony Corp Drive circuit, display device, and electronic device
JP2009128524A (en) * 2007-11-21 2009-06-11 Sony Corp Drive circuit, display device, and electronic device
JP2009180765A (en) * 2008-01-29 2009-08-13 Casio Comput Co Ltd Display driving device, display apparatus and its driving method
JP2009192854A (en) * 2008-02-15 2009-08-27 Casio Comput Co Ltd Display drive device, display device, and drive control method thereof
KR101181106B1 (en) 2008-03-06 2012-09-07 샤프 가부시키가이샤 Active matrix display device
JP2009217021A (en) * 2008-03-11 2009-09-24 Fuji Electric Holdings Co Ltd Image display device
JP5073547B2 (en) 2008-03-27 2012-11-14 ラピスセミコンダクタ株式会社 Display drive circuit and display drive method
TWI386904B (en) * 2008-05-12 2013-02-21 Chimei Innolux Corp Flat display
JP5012729B2 (en) 2008-08-08 2012-08-29 ソニー株式会社 Display panel module, semiconductor integrated circuit, pixel array driving method, and electronic apparatus
JP5012728B2 (en) * 2008-08-08 2012-08-29 ソニー株式会社 Display panel module, semiconductor integrated circuit, pixel array driving method, and electronic apparatus
JP5107824B2 (en) * 2008-08-18 2012-12-26 富士フイルム株式会社 Display device and drive control method thereof
JP5157791B2 (en) 2008-09-29 2013-03-06 カシオ計算機株式会社 Display drive device, display device, and drive control method for display device
JP5012775B2 (en) * 2008-11-28 2012-08-29 カシオ計算機株式会社 Pixel drive device, light emitting device, and parameter acquisition method
JP5012774B2 (en) * 2008-11-28 2012-08-29 カシオ計算機株式会社 Pixel drive device, light emitting device, and parameter acquisition method
JP5012776B2 (en) 2008-11-28 2012-08-29 カシオ計算機株式会社 Light emitting device and drive control method of light emitting device
JP5239974B2 (en) * 2009-03-18 2013-07-17 カシオ計算機株式会社 Electronic device and method for driving electronic device
JP2010237362A (en) * 2009-03-31 2010-10-21 Sony Corp Panel, method for controlling the same, display device and electronic device
JP5218222B2 (en) * 2009-03-31 2013-06-26 カシオ計算機株式会社 Pixel driving device, light emitting device, and driving control method of light emitting device
JP5469384B2 (en) * 2009-06-18 2014-04-16 ラピスセミコンダクタ株式会社 Display driving apparatus and driving method thereof
JP4877536B2 (en) * 2009-07-10 2012-02-15 カシオ計算機株式会社 Pixel drive device, light emitting device, drive control method thereof, and electronic apparatus
JP4935920B2 (en) * 2009-07-10 2012-05-23 カシオ計算機株式会社 Pixel drive device, light emitting device, drive control method thereof, and electronic apparatus
JP5146521B2 (en) 2009-12-28 2013-02-20 カシオ計算機株式会社 Pixel drive device, light emitting device, drive control method thereof, and electronic apparatus
JP5240581B2 (en) 2009-12-28 2013-07-17 カシオ計算機株式会社 Pixel drive device, light emitting device, drive control method thereof, and electronic apparatus
KR101065418B1 (en) 2010-02-19 2011-09-16 삼성모바일디스플레이주식회사 Display device and driving method thereof
KR20120060451A (en) 2010-12-02 2012-06-12 삼성모바일디스플레이주식회사 Organic Light Emitting Display Device and Driving Method Thereof
DE102011016308A1 (en) * 2011-04-07 2012-10-11 Osram Opto Semiconductors Gmbh Display device
CN102930813B (en) * 2012-10-23 2016-03-23 京东方科技集团股份有限公司 Pixel-driving circuit, display device and driving method thereof
WO2015012216A1 (en) * 2013-07-23 2015-01-29 凸版印刷株式会社 El display device and drive method for el display device
JP2015043030A (en) * 2013-08-26 2015-03-05 凸版印刷株式会社 Display device and display method
TWI649741B (en) * 2018-01-30 2019-02-01 友達光電股份有限公司 Threshold voltage compensation circuit and a display panel

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4092857B2 (en) * 1999-06-17 2008-05-28 ソニー株式会社 Image display device
KR100445097B1 (en) * 2002-07-24 2004-08-21 주식회사 하이닉스반도체 Flat panel display device for compensating threshold voltage of panel
JP4247660B2 (en) * 2002-11-28 2009-04-02 カシオ計算機株式会社 Current generation supply circuit, its control method, and display device provided with current generation supply circuit
JP4378087B2 (en) * 2003-02-19 2009-12-02 京セラ株式会社 Image display device
WO2004097782A1 (en) * 2003-05-02 2004-11-11 Koninklijke Philips Electronics N.V. Active matrix oled display device with threshold voltage drift compensation
JP4232193B2 (en) * 2003-05-26 2009-03-04 カシオ計算機株式会社 Current generation supply circuit and display device provided with current generation supply circuit
JP4590831B2 (en) * 2003-06-02 2010-12-01 ソニー株式会社 Display device and pixel circuit driving method
JP2004361753A (en) * 2003-06-05 2004-12-24 Chi Mei Electronics Corp Image display device
JP4939737B2 (en) * 2003-08-08 2012-05-30 株式会社半導体エネルギー研究所 Light emitting device
JP4589614B2 (en) * 2003-10-28 2010-12-01 株式会社 日立ディスプレイズ Image display device
GB0400216D0 (en) * 2004-01-07 2004-02-11 Koninkl Philips Electronics Nv Electroluminescent display devices
JP4798342B2 (en) * 2005-03-31 2011-10-19 カシオ計算機株式会社 Display drive device and drive control method thereof, and display device and drive control method thereof
JP4852866B2 (en) * 2005-03-31 2012-01-11 カシオ計算機株式会社 Display device and drive control method thereof

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