JP2006323234A - ELECTRO-OPTICAL DEVICE, CIRCUIT AND METHOD FOR DRIVING THE SAME, AND ELECTRONIC DEVICE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress both moving image blur and flicker.
Each pixel circuit P constituting a pixel unit 10 controls a period during which an electro-optic element is driven based on a light emission control signal C. The detection circuit 50 detects a change in an image displayed on the pixel unit 10. The light emission control circuit 30 instructs each pixel circuit P corresponding to the region in which the detection circuit 50 has detected a change to drive the electro-optical element in a driving period Pa of a predetermined time length in one frame period. While the first control signal Ca instructing to stop driving in the remaining period is output as the light emission control signal C, each pixel circuit P corresponding to the area where the detection circuit 50 does not detect a change is included in one frame period. A second control signal Cb instructing driving of the electro-optic element in each of a plurality of driving periods spaced apart from each other and instructing stop of driving in the remaining period is output as the light emission control signal C.
[Selection] Figure 1

Description

  The present invention relates to a technique for controlling the behavior of an electro-optical element such as an organic light emitting diode (hereinafter referred to as “OLED (Organic Light Emitting Diode)”) element.

  Conventionally, an electro-optical device has been proposed in which a plurality of pixel circuits each including an electro-optical element are arranged in a planar shape. In this type of electro-optical device, a plurality of pixel circuits are sequentially selected in each frame period, and a data signal is supplied to the selected pixel circuit. An electro-optical device in which the electro-optical element is maintained at a gradation corresponding to the data signal for one frame period from when the data signal is supplied to each pixel circuit until the pixel circuit is selected next is called a hold type. .

As disclosed in Non-Patent Document 1, the hold-type electro-optical device is used due to the difference between the movement of the subject included in the image and the movement of the viewpoint of the observer who follows the movement. A phenomenon (hereinafter referred to as “moving image blur”) in which the contour of the subject perceived by a person becomes unclear occurs. As a measure for solving the motion blur, each electro-optic element is not maintained for the gray scale of each electro-optic element over the frame period, but is used for each electro-optic like an impulse display device represented by CRT (Cathode Ray Tube). There is a method of intermittently driving (lighting) the element.
Shingaku Techniques, EID2001-84 (2002-01) p13-p18 “Time Response of Display and High Quality of Video”, Yashiro Kurita / The Institute of Electronics, Information and Communication Engineers (especially Figure 3)

  However, if there is an interval between the periods in which the electro-optic elements are driven, a phenomenon called flicker in which the brightness of the entire image fluctuates periodically becomes significant. The present invention has been made in view of such circumstances, and aims to solve the problem of suppressing both moving image blur and flicker.

  In order to solve this problem, an electro-optical device according to the present invention controls an electro-optical element driven to a gradation corresponding to a data signal and a period during which the electro-optical element is driven based on a control signal. A pixel unit that displays an image by a plurality of pixel circuits each including a control unit (for example, the light emission control transistor Tel in each embodiment), and a driving unit that supplies a data signal to each of the plurality of pixel circuits for each frame period A detection unit that detects a change in an image displayed by the pixel unit, and each pixel circuit corresponding to a first region (for example, a variation region in each embodiment) in which a change is detected by the detection unit, includes one frame period. Outputs a first control signal instructing driving of the electro-optic element in a driving period of a predetermined time length and instructing stop of driving in the remaining period On the other hand, drive control for outputting a second control signal having a waveform different from that of the first control signal to each pixel circuit corresponding to a second region (for example, a stationary region in each embodiment) in which no change is detected by the detection unit. Means.

  According to this configuration, the pixel circuit corresponding to the first region where the image changes is instructed to drive the electro-optic element in the driving period in one frame period and stop driving in the remaining period. Is done. Therefore, in this first region, moving image blur can be suppressed as compared with a hold-type display device in which the electro-optic element is driven over the entire one frame period. On the other hand, a second control signal having a waveform different from that of the first control signal is output to the pixel circuit corresponding to the second region where the image does not change. Therefore, flicker in the second region can be suppressed by using the second control signal having a waveform that prioritizes flicker suppression. As described above, according to the present invention, both moving image blur and flicker can be suppressed.

  From the viewpoint of effectively suppressing moving image blur, it is desirable that the driving period indicated by the first control signal of the present invention is a single period in one frame period. However, the mode of the drive period indicated by the first control signal (number per frame period and time length) is arbitrary (for example, see FIG. 14).

  In order to suppress flicker, it is desirable that the period of light emission and extinction of each electro-optical element is short. Therefore, in a preferred aspect of the present invention, the second control signal instructs driving of the electro-optic element in each of a plurality of driving periods spaced apart from each other in one frame period, and driving in the remaining period. It is a signal instructing to stop. In order to suppress flicker more effectively, it is desirable that the period for driving each electro-optical element is dispersed as much as possible on the time axis. Therefore, in another aspect of the present invention, one drive control unit is provided. The second frame period includes a first drive period and a second drive period, and the time length from the start point of the first drive period to the start point of the second drive period is substantially half of the frame period. Generate and output a control signal. According to this aspect, since the drive period indicated by the second control signal is evenly distributed on the time axis, flicker can be effectively suppressed.

  However, in the present invention, the mode of the drive period (number per frame period and time length) designated by the second control signal is arbitrary. For example, the second control signal instructs driving of the electro-optical element in a single driving period in one frame period and instructs to stop driving in the remaining period (that is, a signal instructing hold-type driving). ). However, since the flicker is suppressed as the interval between the drive periods is shorter, the interval between the drive periods indicated by the first control signal may be longer than the interval between the drive periods indicated by the second control signal. desirable.

  In a preferred aspect of the present invention, the drive control means includes a sum of time lengths of drive periods defined by the first control signal in one frame period and a drive defined by the second control signal in one frame period. Each control signal is generated and output so that the sum of the time lengths of the periods substantially matches. According to this aspect, when the same gradation is specified for each pixel circuit in the first region and the second region (even if the level of the data signal supplied to each pixel circuit is the same), The gradation of the pixel circuit can be made substantially the same. A specific example of this aspect will be described later as the first embodiment.

  However, the moving image blur is effectively suppressed as the time length in which each pixel circuit in the first region is driven is shorter. Therefore, in a preferred aspect of the present invention, the drive control means is configured such that the total length of the drive periods defined by the first control signal in one frame period is defined by the second control signal in one frame period. Each control signal is generated and output so as to be shorter than the total time length of the driving period. In this aspect, when one gradation is designated for each pixel circuit corresponding to the first area, the gradation of the electro-optic element of the pixel circuit is one level for each pixel circuit corresponding to the second area. It is desirable to provide adjustment means for adjusting the level of the data signal output from the drive means so that the gradation is higher than the gradation of the electro-optical element of the pixel circuit when the key is designated. According to this configuration, although the time lengths of the drive periods of the first region and the second region in one frame are different, the difference in gradation in both regions is suppressed. A specific example of this aspect will be described later as a second embodiment.

  In addition, the moving image blur becomes more prominent as the image changes greatly. Therefore, in another aspect of the present invention, the detection unit specifies the degree of change in the image displayed by the pixel unit (for example, the amount of movement of the subject included in the image per unit time), and the drive control unit includes: The first control signal is generated and output so that the greater the change detected by the detection means, the shorter the total length of the drive period defined by the first control signal. According to this aspect, it is possible to efficiently suppress moving image blur according to the content of the image.

  Further, flicker is suppressed as the distribution area of each pixel circuit driven by the first control signal is smaller. Therefore, in order to reliably suppress both moving image blur and flicker, it is desirable that the detection unit detects a change in the image so that the first region does not exceed a specific area in the pixel portion.

  In another aspect of the present invention, the pixel unit includes a group of a predetermined number of pixel circuits (for example, a group of n pixel circuits belonging to one row) arranged along a first direction (for example, the X direction in each embodiment). ) Arranged in a second direction intersecting the first direction, the detecting means detects the presence / absence of a change of the image for each group, and the drive control means includes each of the first control signal and the second control signal. A control signal corresponding to the detection result regarding the group is output in common to each of the pixel circuits belonging to the group. According to this aspect, since detection of an image change by the detection unit and control of driving based on the result are performed for each group of pixel circuits, for example, a configuration in which an image change is detected for each pixel, The configuration of the electro-optical device is simplified compared to a configuration in which each control signal is supplied separately for each pixel circuit.

  More specifically, the drive control means corresponds to one group (row), each of first signal generation means for generating a first control signal and second signal generation means for generating a second control signal. A plurality of selection circuits (for example, the selector 35 in FIG. 9) and instruction means (for example, FIG. 9) for instructing each of the plurality of selection circuits to select one of the first control signal and the second control signal according to the detection result by the detection means. Each of the selection circuits selects the control signal designated by the instruction means from the first control signal generated by the first signal generating means and the second control signal generated by the second signal generating means. Then, the data is output to each pixel circuit of the group corresponding to the selection circuit. In a more desirable mode, a plurality of selection circuits are divided into blocks every predetermined number, and the instruction means gives a common instruction to the selection circuits belonging to one block (see, for example, FIG. 16). According to this aspect, the configuration for the instruction circuit to control each selection circuit can be simplified (for example, the number of wires from the instruction circuit to the selection circuit can be reduced).

  The electro-optical device according to the invention is used in various electronic apparatuses. A typical example of this electronic apparatus is an apparatus using an electro-optical device as a display device. Examples of this type of electronic device include a personal computer and a mobile phone.

  The present invention is also specified as a method and a circuit for driving an electro-optical device. The driving method according to the present invention includes a plurality of electro-optical elements that are driven to a gray level according to a data signal and a period control unit that controls a period during which the electro-optical elements are driven based on a control signal. A method of driving an electro-optical device that displays an image by a pixel circuit, and supplying a data signal to each of a plurality of pixel circuits for each frame period while detecting a change in an image displayed by the plurality of pixel circuits Each pixel circuit corresponding to the region where the change is detected is instructed to drive the electro-optical element in a driving period of a predetermined time length in one frame period and to stop driving in the remaining period. While outputting a 1st control signal, the 2nd control signal from which a waveform differs from a 1st control signal is output to each pixel circuit corresponding to the area | region where the change of an image is not detected.

  Each of the driving circuits according to the present invention includes an electro-optical element driven to a gradation corresponding to a data signal and a period control unit that controls a period during which the electro-optical element is driven based on a control signal. A circuit for driving an electro-optical device that displays an image by a plurality of pixel circuits, and a driving unit that supplies a data signal to each of the plurality of pixel circuits for each frame period; and an image displayed by the plurality of pixel circuits Each pixel circuit corresponding to the region in which the change is detected by the detecting means for detecting the change is instructed to drive the electro-optic element in a drive period of a predetermined time length in one frame period and the remaining period While outputting a first control signal instructing stop of driving in the pixel circuit corresponding to a region where no change is detected by the detecting means, Comprising a drive control means for outputting a second control signal shape are different. The detection means may be built in the drive circuit or may be arranged as a circuit separate from the drive circuit. Each aspect illustrated about the electro-optical device of this invention can be applied similarly to the drive method and drive circuit which concern on this invention.

<A: First Embodiment>
FIG. 1 is a block diagram showing the configuration of the electro-optical device according to the first embodiment of the invention. As shown in the figure, the electro-optical device D includes a pixel unit 10 in which a plurality of pixel circuits P are arranged in a plane, and a drive circuit 20 that drives each pixel circuit P to control gradation. A control circuit 40 that controls the operation of the drive circuit 20 and a detection circuit 50 that detects a change in an image displayed on the pixel unit 10 are provided. The drive circuit 20, the control circuit 40, and the detection circuit 50 may be mounted in the form of an IC chip on the surface of a substrate on which each pixel circuit P is arranged or on a wiring substrate bonded to the substrate. May be configured by a switching element (typically a TFT (Thin Film Transistor)) formed on the surface of the substrate.

  The pixel unit 10 includes m scanning lines 11 extending in the X direction, m light emission control lines 12 paired with the scanning lines 11 and extending in the X direction, and Y orthogonal to the X direction. N data lines 14 extending in the direction are formed (m and n are both natural numbers). Each pixel circuit P is arranged at a position corresponding to each intersection of the pair of scanning lines 11 and light emission control lines 12 and the data lines 14. Accordingly, these pixel circuits P are arranged in a matrix of m rows × n columns.

  The drive circuit 20 includes a selection circuit 21, a data line drive circuit 23, and a light emission control circuit 30. The control circuit 40 controls each of these circuits by supplying various signals (for example, a horizontal synchronization signal HSYNC described later) that defines the operation timing of the electro-optical device D to the drive circuit 20. Further, the control circuit 40 outputs image data G designating the gradation of each pixel circuit P to the data line driving circuit 23 and the detection circuit 50.

  The selection circuit 21 outputs a scanning signal Y (Y [1], Y [2],..., Y [m]) for sequentially selecting each of the m scanning lines 11 to each scanning line 11. Circuit. That is, as shown in FIG. 2, the selection circuit 21 selects one of the scanning lines 11 for each horizontal scanning period (1H) defined by the horizontal synchronization signal, and is supplied to the selected scanning line 11. While the scanning signal Y is transited to a high level, the scanning signal Y supplied to each unselected scanning line 11 is maintained at a low level. In the present embodiment, a period required to select a total of m scanning lines 11 from the first row to the m-th row is referred to as a “frame period”. The scanning signal Yi (i is 1 ≦ i ≦ m) is at a high level in the i-th horizontal scanning period in one frame period (1F).

  The data line driving circuit 23 generates a data signal X (X [1], X [2],..., X [n]) corresponding to the image data G of each pixel circuit P belonging to the selected row by the selection circuit 21. And output to each data line 14. The data signal X is a current signal (current amount Idata) corresponding to the gradation specified for each pixel circuit P by the image data G. On the other hand, the light emission control circuit 30 defines a light emission control signal C (C [1], C [2],..., C [] that defines a period during which the pixel circuits P in each row actually have gradation according to the image data G. m]) is generated and output to each light emission control line 12. A specific example of the configuration of the light emission control circuit 30 will be described later. The selection circuit 21 and the light emission control line 12 constitute a so-called scanning line driving circuit (Y driver).

  Next, FIG. 3 is a circuit diagram showing a configuration of one pixel circuit P. In the drawing, only the pixel circuit P in the j-th column (j is an integer satisfying 1 ≦ j ≦ n) belonging to the i-th row (i is an integer satisfying 1 ≦ i ≦ m) is illustrated. However, the other pixel circuits P have the same configuration.

  As shown in FIG. 3, the pixel circuit P of the present embodiment includes a p-channel type drive transistor Tdr, three n-channel type transistors (light emission control transistor Tel, selection transistor Tsel, and switching transistor Tsw), It includes a capacitive element C that holds a voltage, and an electro-optic element 17 interposed between a power supply line to which a higher potential Vdd of the power supply is supplied and a ground line to which a lower potential Gnd is supplied. The electro-optic element 17 in this embodiment is an OLED element in which a light emitting layer made of an organic EL material is interposed in a gap between an anode and a cathode, and emits light with a gradation (luminance) corresponding to the amount of drive current Iel. .

  The drive transistor Tdr is an element for controlling the amount of the drive current Iel. The source is connected to the power supply line to which the higher potential Vdd of the power supply is supplied, and the drain is connected to the drain of the light emission control transistor Tel. Is done. The light emission control transistor Tel is a switching element for defining a period during which the drive current Iel is actually supplied to the electro-optical element 17 (that is, a period during which the electro-optical element 17 actually emits light), and a source is the electro-optical element. The anode is connected to the anode 17 and the gate is connected to the light emission control line 12.

  On the other hand, the switching transistor Tsw is a switching element interposed between the gate and drain of the driving transistor Tdr, and the gate thereof is connected to the scanning line 11 together with the gate of the selection transistor Tsel. When the switching transistor Tsw is turned on, the drive transistor Tdr is diode-connected. The selection transistor Tsel is a switching element that is inserted between the drain of the drive transistor Tdr and the data line 14 and switches between conduction and non-conduction of the two.

  In the above configuration, when the scanning signal Y [i] transitions to a high level in the i-th horizontal scanning period in each frame period (see FIG. 2), the switching transistor Tsw is turned on and the driving transistor Tdr is turned on by the diode. Function as. At this time, since the selection transistor Tsel is in the on state, the current Idata of the data signal X [j] flows into the data line 14 from the power supply line via the driving transistor Tdr and the selection transistor Tsel. Therefore, a charge corresponding to the potential of the gate of the drive transistor Tdr (that is, a charge corresponding to the current Idata) is accumulated in the capacitive element C.

  Next, when the i-th horizontal scanning period elapses and the scanning signal Y [i] becomes low level, both the switching transistor Tsw and the selection transistor Tsel are turned off. Therefore, the voltage between the gate and the source of the driving transistor Tdr is maintained at a voltage corresponding to the charge accumulated in the capacitive element C in the immediately preceding horizontal scanning period. In this state, when the light emission control signal C [i] transitions to a high level, the light emission control transistor Tel transitions to the on state, and as a result, a drive current (that is, the data signal X [j]) corresponding to the gate potential of the drive transistor Tdr. Current) Iel is supplied from the power supply line to the electro-optical element 17 via the drive transistor Tdr. The electro-optical element 17 emits light with a luminance proportional to the drive current Iel.

  By the way, from the viewpoint of sufficiently ensuring the luminance of each electro-optic element 17, it is desirable that the period during which each electro-optic element 17 actually emits light is long. However, for example, when a hold-type display in which the light emission of the electro-optic element 17 is maintained over one frame period, a subject (object) that moves with time in an image displayed by the pixel unit 10. The moving image blur in which the outline of the image becomes unclear becomes remarkable. The principle of this moving image blur will be described as follows.

  FIG. 4 shows a temporal change in the image displayed in one row of the pixel unit 10 under the hold-type display (FIG. 4A) and the image actually perceived by the observer ( It is explanatory drawing which shows (b)). In FIG. 5A, the vertical axis represents time, and the horizontal axis represents the position in the X direction. In the figure, it is assumed that a black subject B displayed with white as a background moves to the right by three pixels every frame period. As shown in the figure, in the hold-type display, each electro-optic element 17 is maintained at a substantially constant gradation from the start point to the end point of each frame period.

  An observer who visually recognizes this image moves the viewpoint so as to follow the movement of the subject B. Assuming that the viewpoint follows the movement of the subject B accurately and smoothly, the observer's viewpoint is substantially constant so as to follow the subject B as represented by the arrow V in FIG. Move continuously to the right at a speed of. As described above, the subject B that is actually displayed moves to the right discretely in each frame period, whereas the observer's viewpoint smoothly follows the movement of the subject B.

  Here, FIG. 4B shows the position of the subject B0 formed at a specific part on the retina of the observer who visually recognizes the above image (subject B) as a relative position with this part as a reference. It is explanatory drawing shown in figure. As described above, since the viewpoint of the observer moves to the right at a substantially constant speed, the subject B moves to the right discretely for each frame period, so the relative position of the subject B with respect to the viewpoint Shifts to the left as it approaches the end of one frame period. That is, as shown in FIG. 4B, the contour of the subject B0 that is actually perceived by the observer varies over a range Δ in one frame period. As a result, the outline of the subject B is perceived unclearly by the user. In other words, it can be explained that the end of the subject B becomes unclear because the black of the subject B and the white of the region adjacent thereto are averaged (integrated) over one frame period.

  In order to suppress such blurring of moving images, in this embodiment, as will be described in detail below with reference to FIG. 5, the electro-optic element 17 is selectively used in only a part of one frame period. Is to be driven. FIG. 5A is an explanatory diagram corresponding to FIG. 4A, and shows how the image displayed in one row of the pixel unit 10 of the present embodiment changes over time. Also in the figure, it is assumed that the black subject B moves to the right by 3 pixels every frame period with white as the background. FIG. 6 is a timing chart showing the waveform of the light emission control signal C [i] and the state of the electro-optic element 17 at that time (a distinction between light emission and non-light emission).

  As shown in FIGS. 5A and 6, the electro-optical element 17 has a luminance corresponding to the data signal X in a period Pa (hereinafter referred to as “driving period”) Pa of one frame period. The light is emitted during the remaining period. That is, the light emission control signal C [i] supplied to each pixel circuit P via the light emission control line 12 maintains a high level (a level at which the light emission control transistor Tel is turned on) in the driving period Pa and It becomes a waveform signal Ca (hereinafter referred to as “first control signal”) Ca that maintains a low level in the remaining period. According to such a driving method (hereinafter referred to as “first light emission control method”), as shown in FIG. 5B, a deviation in the X direction occurs in the subject B0 perceived by the observer in each frame period. Therefore, the end of the subject B displayed on the pixel unit 10 is clearly perceived by the user. That is, according to the first light emission control method, moving image blur can be effectively suppressed.

  On the other hand, in the first light emission control method, the time length of the period for stopping the light emission of the electro-optical element 17 (that is, the interval between the driving periods Pa that follow each other) is relatively long. Therefore, if the first light emission control method is applied to all the pixel circuits P of the pixel unit 10, flicker in which the brightness of the image perceived by the user fluctuates periodically may become apparent. Therefore, in this embodiment, in addition to the first light emission control method, a method capable of effectively suppressing flicker (hereinafter referred to as “second light emission control method”) is used in combination.

  As shown in FIG. 6B, in the second light emission control method, the electro-optical element 17 is provided in each of two drive periods Pb (Pb1 and Pb2) spaced apart from each other in one frame period. While emitting light, the light is extinguished during the remaining period. That is, the light emission control signal C [i] supplied to each pixel circuit P via the light emission control line 12 is set to the high level for turning on the light emission control transistor Tel in each of the driving periods Pb (Pb1 and Pb2). The waveform signal (hereinafter referred to as “second control signal”) Cb is maintained and maintained at the low level in the remaining period. As described above, flicker can be effectively suppressed by reducing the light emission and extinguishing periods by dispersing the light emission timing of the electro-optical element 17.

  Each drive period Pb in the second light emission control method is set to a time length “L” that is approximately half of the drive period Pa in the first light emission control method. Therefore, the total time length of the electro-optic element 17 emitting light in one frame period under the first light emission control method and the time length of the electro-optic element 17 emitting light in one frame period under the second light emission control method. Is approximately equal to (2L). The time length from the start point of one drive period Pb1 to the start point of the next drive period Pb2 is approximately half (1 / 2F) of one frame period.

  By the way, moving image blurring occurs in an area of the image where the content has changed (for example, an area where the subject has moved). Therefore, in the present embodiment, an area (hereinafter referred to as “variable area”) in which the content (the gradation of each electro-optical element 17) has changed from the image in the immediately preceding frame period of the image displayed on the pixel unit 10 in the present embodiment. While the first light emission control method effective for suppressing moving image blur is applied, a portion in which the content of the image does not change or a change is small compared to the immediately preceding frame period (hereinafter, these are collectively referred to as “static The second light emission control method is applied to the “region”. The detection circuit 50 shown in FIG. 1 is a means for distinguishing one image into a still region and a variation region by detecting a change in the contents of each image that is temporally adjacent. The detection circuit 50 according to the present embodiment divides the image into a still area and a fluctuation area in units of rows.

  FIG. 7 is a block diagram showing a specific configuration of the detection circuit 50, and FIG. 8 is an explanatory diagram showing the operation of the detection circuit 50. As shown in FIG. 7, the detection circuit 50 of this embodiment includes a buffer 51, a comparison circuit 52, and a signal generation circuit 53. The image data G for one image supplied from the control circuit 40 is supplied to the buffer 51 and the comparison circuit 52. The buffer 51 is means (so-called frame memory) for storing image data G for one image composed of pixels of vertical m rows × horizontal n columns. Accordingly, the comparison circuit 52 is supplied with the image data G of the (k + 1) th frame from the control circuit 40 and the image data G of the immediately preceding kth frame from the buffer 51 (k is a natural number). .

  The comparison circuit 52 is means for detecting a difference between the image data G of the kth frame and the image data G of the (k + 1) th frame. More specifically, as shown in FIG. 8, the comparison circuit 52 determines the gradation value of each pixel constituting the (k + 1) th frame image and the gradation of each pixel constituting the kth frame image. The values are compared, and as shown in part (a) of the figure, the number of pixels that do not match (hereinafter referred to as “degree of change”) is counted for each row of the image. The count result is output to the signal generation circuit 53. FIG. 8 illustrates a case where the circular subject Ob moves diagonally downward to the right from the kth frame to the (k + 1) th frame. In this case, each row belonging to the range A1 from the upper end of the subject Ob in the j-th frame to the lower end of the subject Ob in the (k + 1) -th frame exceeds zero, while each row belonging to the other range ( That is, the frequency of change in each row in which the gradation does not change between the kth frame and the (k + 1) th frame is zero. However, in FIG. 8A, it is assumed that the frequency of change exceeds zero for each row belonging to the range A2 in addition to the range A1 due to an accidental cause such as noise.

  The signal generation circuit 53 generates and outputs a detection signal M based on the comparison result by the comparison circuit 52. This detection signal M is a signal that designates the number of a row to be classified as a fluctuation region in one image. More specifically, the signal generation circuit 53 first executes a filter (low-pass filter) process in order to remove an error caused by noise from the comparison result by the comparison circuit 52. By this processing, for example, the change frequency of each row belonging to the range A2 in FIG. 8A is updated to zero. Furthermore, the signal generation circuit 53 compares the change frequency of each row with a predetermined threshold TH, and outputs the number of the row determined that the change frequency exceeds the threshold TH as the detection signal M. For example, in the case illustrated in FIG. 8A, the number of each row belonging to the range A1 (that is, each row classified into the fluctuation region) is output as the detection signal M. A region not specified by the detection signal M is a still region.

  As shown in FIG. 1, the detection signal M is supplied from the detection circuit 50 to the light emission control circuit 30. The light emission control circuit 30 drives the electro-optic elements 17 in each row specified by the detection signal M as the fluctuation region by the first light emission control method, and the second light emission control method for the electro-optic elements 17 in each row divided into the stationary regions. It is means for driving by. More specifically, the light emission control circuit 30 selects the first control signal Ca shown in FIG. 6A as the light emission control signal C [i] for the pixel circuits P in each row classified as the fluctuation region. And the second control signal Cb shown in FIG. 6B is selected as the light emission control signal C [i] for the pixel circuits P in each row classified as the still region. Output to the light emission control line 12.

  FIG. 9 is a block diagram showing a specific configuration of the light emission control circuit 30. As shown in the figure, the light emission control circuit 30 includes a first signal generation circuit 311 and a second signal generation circuit 312, a first shift register 331 and a second shift register 332, each having a separate light emission control line. 12 and a decoder 37 that controls the operation of each selector 35 based on the detection signal M supplied from the detection circuit 50.

  The first signal generating circuit 311 is means for generating and outputting a first control signal Ca having the waveform shown in FIG. The first shift register 331 disposed in the subsequent stage of the first signal generation circuit 311 includes a plurality of unit circuits (FFs) whose operation timings are defined by the horizontal synchronization signal HSYNC supplied from the control circuit 40 in multiple stages. It is the structure connected to. As shown in FIG. 2, the first shift register 331 sequentially shifts the first control signal Ca output from the first signal generation circuit 311 at a timing synchronized with the horizontal synchronization signal HSYNC. The signals Ca [1] to Ca [m] are output. On the other hand, the second signal generation circuit 312 is means for generating the second control signal Cb having the waveform shown in FIG. As shown in FIG. 2, the second shift register 332 sequentially shifts the second control signal Cb generated by the second signal generation circuit 312 in synchronization with the horizontal synchronization signal HSYNC to thereby generate the second control signal Cb [ 1] to Cb [m].

  The first control signal Ca [i] and the second control signal Cb [i] are input to the i-th selector 35. Each selector 35 is means for selecting either the first control signal Ca [i] or the second control signal Cb [i] in accordance with an instruction from the decoder 37. The signal selected here is output as the light emission control signal C [i] to the light emission control line 12 in the i-th row. On the other hand, the decoder 37 instructs the selector 35 corresponding to each row designated by the detection signal M (that is, each row belonging to the fluctuation region) to select the first control signal Ca [i], while each row not designated here ( That is, the selector 35 corresponding to each row belonging to the still area is instructed to select the second control signal Cb [i].

  With the above configuration, the pixel circuits P in each row belonging to the variable region are driven by the first light emission control method, while the pixel circuits P in each row belonging to the still region are driven by the second light emission control method. For example, when the i-th row is classified as a static region and the (i + 1) -th row is classified as a variable region (that is, the boundary between the variable region and the static region is the i-th row and (i) +1) if it is between the first line). In this case, as shown in FIG. 10, the second control signal Cb [i] output from the second shift register 332 is supplied to each pixel circuit P in the i-th row as the light emission control signal C [i]. Is done. Therefore, the electro-optic element 17 of each pixel circuit P in the i-th row has a luminance corresponding to the data signal X in two drive periods Pb (Pb1 and Pb2) spaced apart from each other in one frame period. It emits light and turns off during other periods. On the other hand, the electro-optical element 17 of each pixel circuit P in the (i + 1) -th row emits light with a luminance corresponding to the data signal X in a single drive period Pa in one frame period, and other periods. The light goes off.

  As described above, in the present embodiment, the first light emission control method effective for suppressing moving image blur is applied to each pixel circuit P belonging to the fluctuation region, and flicker is applied to each pixel circuit P belonging to the still region. Since the second light emission control method that is effective in suppressing the image is applied, both moving image blur and flicker can be suppressed. Note that, in the variable region to which the first light emission control method is applied, the light emission interval of the electro-optical element 17 becomes longer, and therefore flicker may become apparent as compared with the hold type display. However, under the general tendency that the area where the subject of the image moves or changes is relatively narrow, the area of the area classified as the fluctuation area by the detection circuit 50 is often small. Since flicker is difficult to be perceived by the user when the area is small, in the present embodiment, even if flicker occurs in the fluctuation region, this is hardly perceived by the user.

  By the way, as a configuration for suppressing flicker in the still region, a configuration in which a sufficient time length is secured in the drive period Pb in the second light emission control method (for example, the drive period Pb is about one frame period as in the hold type). A configuration secured for a long time) is also conceivable. However, in this case, since the time length of the period during which the electro-optic element 17 emits light is greatly different between the stationary region and the varying region, the luminance varies between the stationary region and the varying region, and display unevenness is displayed to the user. May be perceived. On the other hand, in the present embodiment, the sum of the time lengths of the drive periods Pa per frame period in the first light emission control method and the sum of the time lengths of the drive periods Pb per frame period in the second light emission control method Are approximately the same. Accordingly, display brightness can be suppressed by equalizing the brightness of the still area and the brightness of the fluctuation area.

<B: Second Embodiment>
Next, the configuration of the electro-optical device D according to the second embodiment of the invention will be described. In addition, the same code | symbol is attached | subjected about the element similar to 1st Embodiment among this embodiment, and the description is abbreviate | omitted suitably.

  As described with reference to FIGS. 4 and 5, the motion blur is suppressed as the period during which the electro-optic element 17 emits light is shorter in one frame period. Accordingly, it is desirable that the driving period Pa is short in the first light emission control method. However, simply shortening the driving period Pa may result in insufficient luminance of the electro-optic element 17 in the fluctuation region, and unevenness in luminance may occur between the fluctuation region and the stationary region. This problem will be described in detail as follows.

  FIG. 11 is a timing chart for explaining operations in each of the first light emission control method and the second light emission control method. As shown in FIG. 5A, the first control signal Ca supplied to each pixel circuit P as the light emission control signal C [i] under the first light emission control method is shorter than that in the first embodiment. The high level is maintained in the driving period Pa of the time length “L”. On the other hand, as shown in FIG. 11A, the waveform of the second control signal Cb is the same as that of the first embodiment. That is, the total time length for causing each electro-optical element 17 to emit light in one frame period under the second light emission control method is “2L”, whereas each electro-optical element 17 is changed in the first light emission control method. The total length of time for light emission is “L”. Therefore, if the data signal X of the same level corresponding to one gradation is supplied to the pixel circuit P in the static region and the pixel circuit P in the variable region, one frame of each electro-optic element 17 located in the variable region. The total light emission amount during the period is approximately half of the total light emission amount of each electro-optic element 17 located in the stationary region. This difference in the amount of emitted light is perceived as uneven display by the user.

  In order to solve this problem, in the present embodiment, the sum of the light emission amounts of the electro-optic element 17 in one frame period when the same gradation is specified is substantially the same in the stationary region and the fluctuation region. The level (current Idata) of the data signal X supplied to each pixel circuit P in the fluctuation region is appropriately adjusted. More specifically, as shown in FIG. 11, the current amount Ia of the drive current Iel supplied to the electro-optic element 17 in the fluctuation region when a certain gradation is specified is specified for that gradation. The level of the data signal X supplied to each pixel circuit P is adjusted so as to be approximately twice the amount of current Ib supplied to the electro-optic element 17 in the stationary region. The adjustment circuit 60 shown in FIG. 12 is means for executing this adjustment.

  The adjustment circuit 60 is supplied with the detection signal M for instructing the distinction between the fluctuation region and the still region from the detection circuit 50, and the image data G of each pixel circuit P is sequentially supplied from the control circuit 40. The adjustment circuit 60 converts the image data G of the pixel circuits P in each row specified in the fluctuation region by the detection signal M from the image data G of each pixel circuit P into image data Gnew having a numerical value larger than this. Output to the line drive circuit 23. The adjustment circuit 60 outputs the image data G of the pixel circuits P in each row belonging to the still region to the data line driving circuit 23 without executing any processing. Specific contents of the operation of the adjustment circuit 60 converting the image data G into the image data Gnew are as follows.

  For example, assume that the gradation value specified by the image data G is proportional to the actual luminance of the electro-optic element 17 as illustrated as the characteristic Fa in FIG. In this case, when the image data G designating the gradation value g is supplied to the pixel circuit P belonging to the fluctuation region, the adjustment circuit 60 sets the gradation value g1 (= 2g) that is approximately twice the gradation value g. The designated image data Gnew is generated and output to the data line driving circuit 23. The image data Gnew may be calculated by a predetermined calculation including the image data G, or generated based on a lookup table in which the image data G and the image data Gnew input to the adjustment circuit 60 are associated in advance. May be. On the other hand, when the image data G specifying the gradation value g is supplied to the pixel circuit P belonging to the still region, the adjustment circuit 60 outputs the image data G to the data line driving circuit 23 as it is. Then, the data line driving circuit 23 generates a data signal X based on the image data G and the image data Gnew supplied from the adjustment circuit 60 and outputs the data signal X to each data line 14.

  With the above processing, the current amount Ia of the drive current Iel supplied to the electro-optical element 17 in the fluctuation region becomes approximately twice the current amount Ib supplied to the electro-optical element 17 in the stationary region. As a result, as shown in FIG. 13, the luminance La of the fluctuation region is approximately twice the luminance Lb of the still region. In other words, the total amount of light emission of the electro-optic element 17 in one frame period is substantially the same between the fluctuation region and the stationary region. Therefore, according to the present embodiment, the time length of the driving period Pa in the first light emission control method is approximately half of the total time length of the driving period Pb in the second light emission control method in order to realize effective suppression of moving image blur. Despite being shortened, the difference in luminance between the fluctuation region and the still region can be suppressed.

  By the way, depending on the input / output characteristics of the data line driving circuit 23 and the characteristics of each pixel circuit P (characteristics of each transistor and the electro-optical element 17), it is designated by the image data G as illustrated as the characteristic Fb in FIG. In some cases, the luminance of the electro-optic element 17 changes nonlinearly with respect to a certain gradation value. Under this configuration, even if the gradation value g of the image data G is simply doubled by the adjustment circuit 60, the luminance of the electro-optical element 17 does not reach double (it remains at the luminance La '). That is, in order to make the luminance of the electro-optical element 17 twice that of the second light emission control method, it is necessary to generate image data Gnew specifying the gradation value g2 shown in FIG. In such a case, it is difficult to calculate the image data Gnew by a predetermined calculation based on the image data G. Therefore, a configuration in which the adjustment circuit 60 specifies the image data Gnew based on a table (lookup table) in which the image data G and the image data Gnew are associated in advance is desirable.

<C: Modification>
Various modifications can be made to the embodiments described above. An example of a specific modification is as follows. In addition, you may combine each following aspect suitably.

(1) Modification 1
In each embodiment, the case where the driving period Pa is a single period continuous in one frame period is exemplified, but the mode of the driving period Pa in the first light emission control method is not limited to this. For example, as shown in FIG. 14, also in the first light emission control method, the electro-optical element 17 is caused to emit light in each of a plurality of drive periods Pa (Pa1 · Pa2) spaced from each other within one frame period. Also good. FIG. 15 is a drawing corresponding to FIG. 4 and FIG. 5, and shows how the image displayed in one row of the pixel unit 10 changes over time under the present modification (FIG. 15A). The mode of the image perceived by the observer ((b) in the figure) is shown. When the electro-optic element 17 is caused to emit light in each of the plurality of driving periods Pa as shown in FIGS. 14 and 15 (a), the retina of the observer is displayed in the driving period Pa1 as shown in FIG. 15 (b). An image of the displayed subject B and an image of the subject B displayed during the driving period Pa2 are formed. Therefore, as compared with the case where the hold-type display is adopted (in the case of FIG. 4), the shift amount Δ of the end of the subject B0 perceived by the user is reduced. As described above, in the present invention, each electro-optical element 17 in the region where the image change is detected (variable region) is driven in a part of one frame period (driving period Pa). At the same time, it is sufficient that the driving is stopped in the remaining period, and the number of driving periods Pa included in one frame period and the length of each time are not critical.

  In the second light emission control method of each embodiment, the configuration in which the electro-optic element 17 emits light in each of the two drive periods Pb (Pb1 and Pb2) in one frame period is exemplified. The number of drive periods Pb and the respective time lengths are arbitrarily changed. For example, in the second light emission control method, the electro-optic element 17 may be driven in three or more driving periods Pb set in one frame period, or the time length of each driving period Pb included in one frame period May be different from each other. In addition, since the second light emission control method prioritizes flicker suppression, it is not always necessary to set a plurality of drive periods Pb for one frame period. The electro-optic element 17 may be driven in a single driving period Pb occupying all the sections.

(2) Modification 2
As understood from the description of FIG. 4, the degree of moving image blur (amount of deviation Δ) perceived by the user becomes more prominent as the amount of movement of the subject for each frame period (that is, the speed of movement of the subject) increases. . On the other hand, as described with reference to FIGS. 5 and 11, the amount of deviation Δ of the end of the subject B0 perceived by the user is reduced as the drive period Pa in the first light emission control method is shorter. The Therefore, the light emission control signal C [i] (more precisely, the first control signal Ca [i] is set so that the time length of the driving period Pa in the first light emission control method becomes shorter as the moving speed of the subject B of the image increases. ]) May be adjusted by the light emission control circuit 30.

(3) Modification 3
As described in the first embodiment, flicker may become more prominent under the first light emission control method than in the second light emission control method. On the other hand, the user perceives flicker more clearly as the area of the region where the brightness of the image fluctuates periodically is larger. Therefore, the area of the area designated as the variable area may be limited. More specifically, even when a change in content is detected over the entire image, the area of the region designated as the variable region may be limited to about 30% of the image. In order to realize this function, the signal generation circuit 53 appropriately adjusts the threshold value TH so that, for example, the ratio of rows in which the frequency of change exceeds the threshold value TH (that is, the number of rows determined to be a fluctuation region) falls below a predetermined value. To do. According to this modification, the area of the region to which the first light emission control method is applied is limited, so that flicker can be effectively suppressed.

(4) Modification 4
In each embodiment, the configuration in which the image displayed on the pixel unit 10 is divided into one of a static region and a variable region one row at a time is illustrated. However, the static region is a block obtained by dividing m rows into predetermined numbers. And it is good also as a structure by which a fluctuation area is recognized. For example, when the total number of image changes in a plurality of rows belonging to one block exceeds a threshold value, all rows belonging to that block are designated as a variable region and the first light emission control method is applied. It is.

  In such a configuration in which light emission is controlled in units of blocks, the configuration of FIG. 16 is preferably employed instead of the configuration of FIG. In this configuration, m selectors 35 are divided into blocks B every predetermined number (here, “12”) so as to correspond to the blocks of each pixel circuit P. A common instruction is input from the decoder 37 to each selector 35 belonging to one block B. According to this configuration, the first light emission control method or the second light emission control method can be selectively applied to each block of each pixel circuit P. Further, as compared with the light emission control circuit 30 illustrated in FIG. 9, there is an advantage that the number of wirings extending from the decoder 37 to each selector 35 can be reduced.

  Also, as shown in FIG. 17, the first control signal Ca [i] output from the first shift register 331 and the second control signal Cb [i] output from the second shift register 332 are combined into one block. It is good also as a structure shared by several rows (here "12 rows") to which it belongs. In the configuration shown in the drawing, twelve light emission control lines 12 belonging to one block are connected in common to the output terminal of one selector 35. According to this configuration, as in the configuration of FIG. 16, the first light emission control method or the second light emission control method can be selectively applied to each block in which each pixel circuit P is divided. However, in the configuration of FIG. 17, after the data signal X is supplied to all the pixel circuits P belonging to one block, the light emission control transistor Tel of each pixel circuit P belonging to that block is turned on. Is desirable. When the light emission control transistor Tel is turned on before the voltage corresponding to the data signal X is applied to the gate of the driving transistor Tdr, each electro-optical element 17 is caused to emit light with the intended luminance corresponding to the data signal X. It is because it is not possible.

(5) Modification 5
In the second embodiment, the configuration in which the adjustment circuit 60 processes the image data G has been exemplified. However, the method for suppressing unevenness in luminance between the stationary region and the fluctuation region is not limited to this. For example, the image data G may be supplied to the data line driving circuit 23 without any processing, while the level of the data signal X generated by the data line driving circuit 23 is different between the stationary region and the fluctuation region. Good. For example, the level of the data signal X supplied to each pixel circuit P in the fluctuation region when a certain gradation is specified is changed to the level of the data signal X supplied to each pixel circuit in the still region where the gradation is specified. For example, the level is adjusted to approximately twice the level. Thus, in the present invention, it is sufficient if the level of the data signal X supplied to each pixel circuit P is consequently different between the fluctuation region and the still region, and the object to be actually processed is the image data. It does not matter whether it is G or data signal X. In the second embodiment, the configuration in which the level of the data signal X supplied to each pixel circuit P in the fluctuation region is increased is illustrated. Conversely, the level is supplied to each pixel circuit P in the still region. The level of the data signal may be reduced.

(6) Modification 6
The configuration of the pixel circuit P is not limited to the example shown in FIG. For example, instead of the pixel circuit P of the current programming method illustrated in FIG. 3 (the method in which the gradation of the electro-optic element 17 is adjusted according to the current Idata of the data line 14), the electric current is determined according to the voltage of the data line 14. A voltage programming pixel circuit in which the gradation of the optical element 17 is adjusted may be employed. In each embodiment, the OLED element is exemplified as the electro-optical element 17, but the electro-optical element in the present invention is not limited to this. For example, instead of OLED elements, liquid crystal elements, inorganic EL elements, field emission (FE) elements, surface-conduction electron (SE) elements, ballistic electron surface emitting (BS) Various electro-optical elements such as an element and an LED (Light Emitting Diode) element can be used. As described above, the electro-optical element in the present invention may be an element whose gradation changes with the application of electric energy. In the pixel circuit of the present invention, an electro-optical element (typically a light-emitting element that emits light with a luminance corresponding to a data signal) driven to a gradation corresponding to a data signal, and the electro-optical element are actually driven. It is only necessary to include means for controlling the period (more specifically, the period during which the electro-optic element actually emits light) (for example, the light emission control transistor Tel in each embodiment), and the specific configuration is not limited. is there.

<D: Application example>
Next, an electronic apparatus using the electro-optical device D according to the present invention will be described. FIG. 18 is a perspective view showing a configuration of a mobile personal computer that employs the electro-optical device D according to any one of the embodiments described above as a display device. The personal computer 2000 includes an electro-optical device D as a display device and a main body 2010. The main body 2010 is provided with a power switch 2001 and a keyboard 2002. Since the electro-optical device D uses an OLED element as the electro-optical element 17, it is possible to display an easy-to-see screen with a wide viewing angle.

  FIG. 19 shows a configuration of a mobile phone to which the electro-optical device D according to the embodiment is applied. A cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and an electro-optical device D as a display device. By operating the scroll button 3002, the screen displayed on the electro-optical device D is scrolled.

  FIG. 20 illustrates a configuration of a personal digital assistant (PDA) to which the electro-optical device D according to the embodiment is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and an electro-optical device D as a display device. When the power switch 4002 is operated, various types of information such as an address book and a schedule book are displayed on the electro-optical device D.

  Electronic devices to which the electro-optical device D according to the present invention is applied include those shown in FIGS. 18 to 20, digital still cameras, televisions, video cameras, car navigation devices, pagers, electronic notebooks, and electronic papers. Calculators, word processors, workstations, videophones, POS terminals, printers, scanners, copiers, video players, devices with touch panels, and the like.

1 is a block diagram illustrating a configuration of an electro-optical device according to a first embodiment. It is a timing chart which shows the waveform of the signal in connection with the drive of each pixel circuit. It is a circuit diagram which shows the structure of one pixel circuit. It is a figure for demonstrating the principle in which animation blur occurs. It is a figure for demonstrating the principle by which moving image blurring is eliminated by this embodiment. It is a timing chart for demonstrating a 1st light emission control system and a 2nd light emission control system. It is a block diagram which shows the structure of a detection circuit. It is a figure for demonstrating operation | movement of a detection circuit. It is a block diagram which shows the structure of the light emission control circuit. 6 is a timing chart for explaining a specific example of the operation of the electro-optical device. 12 is a timing chart for explaining the operation of the electro-optical device according to the second embodiment. FIG. 6 is a block diagram illustrating a configuration of an electro-optical device according to a second embodiment. It is a graph for demonstrating operation | movement of an adjustment circuit. 10 is a timing chart for explaining the contents of a first light emission control method according to Modification 1. FIG. 10 is a diagram for explaining moving image blurring that occurs in modification example 1; FIG. 10 is a block diagram showing a configuration of a light emission control circuit in Modification 4. It is a block diagram which shows the other structure of the light emission control circuit in the modification 4. It is a perspective view which shows the specific form of the electronic device which concerns on this invention. It is a perspective view which shows the specific form of the electronic device which concerns on this invention. It is a perspective view which shows the specific form of the electronic device which concerns on this invention.

Explanation of symbols

D: Electro-optical device, 10: Pixel section, 11: Scan line, 12: Light emission control line, 14: Data line, 17: Electro-optical element, 20: Drive circuit, 21: Selection circuit , 23... Data line drive circuit, 30... Light emission control circuit, 311... First signal generation circuit, 312... Second signal generation circuit, 331. 35... Selector, 37... Decoder, 40... Control circuit, 50 .. Detection circuit, 51... Buffer, 52 .. Comparison circuit, 53.

Claims (15)

Pixels that display an image by a plurality of pixel circuits each including an electro-optic element driven to a gradation corresponding to a data signal and a period control unit that controls a period during which the electro-optic element is driven based on a control signal And
Driving means for supplying a data signal to each of the plurality of pixel circuits every frame period;
Detecting means for detecting a change in an image displayed by the pixel unit;
Each pixel circuit corresponding to the first region in which the change is detected by the detecting unit is instructed to drive the electro-optic element in a driving period having a predetermined time length in one frame period, and in the remaining period A second control signal that outputs a first control signal instructing to stop driving, and that has a waveform different from that of the first control signal, in each pixel circuit corresponding to a second region in which no change is detected by the detection unit. And an electro-optical device. The electro-optical device according to claim 1, wherein the drive control unit generates and outputs the first control signal so that driving of the electro-optical element is instructed in a single drive period of one frame period. . The drive control means instructs each pixel circuit corresponding to the second region to drive the electro-optical element in each of a plurality of drive periods spaced apart from each other in one frame period, and the remainder The electro-optical device according to claim 1, wherein a signal instructing stop of driving in the period is output as the second control signal. In the drive control means, one frame period includes a first drive period and a second drive period, and the time length from the start point of the first drive period to the start point of the second drive period is the frame period. The electro-optical device according to claim 3, wherein the second control signal is generated and output so as to be approximately half. The drive control means includes a sum of time lengths of drive periods defined by the first control signal in one frame period and a time length of drive periods defined by the second control signal in one frame period. The electro-optical device according to any one of claims 1 to 4, wherein each control signal is generated and output so that the total sum of the two substantially matches. The drive control means generates and outputs each control signal such that the interval between the drive periods indicated by the first control signal is longer than the interval between the drive periods indicated by the second control signal. The electro-optical device according to claim 1. The electro-optic element of each pixel circuit is driven to a gradation according to the level of the data signal,
The drive control means is configured such that the sum of the time lengths of the drive periods specified by the first control signal in one frame period is the time length of the drive period specified by the second control signal in one frame period. Generate and output each control signal to be shorter than the sum of
When one gradation is designated for each pixel circuit corresponding to the first area, the gradation of the electro-optic element of the pixel circuit is equal to that for each pixel circuit corresponding to the second area. The electrical apparatus according to claim 1, further comprising an adjusting unit that adjusts a level of the data signal output from the driving unit so that the gray level of the electro-optical element of the pixel circuit when specified is higher. Optical device. The detection means specifies a degree of change of an image displayed by the pixel unit;
The drive control means generates and outputs the first control signal such that the greater the change detected by the detection means, the shorter the total time length of the drive period defined by the first control signal. The electro-optical device according to claim 1. The electro-optical device according to claim 1, wherein the detection unit detects a change in an image so that the first region does not exceed a specific area in the pixel unit. The pixel unit is configured by arranging a group of a predetermined number of pixel circuits arranged along a first direction in a second direction intersecting the first direction,
The detection means detects the presence / absence of an image change for each group,
2. The drive control unit outputs a control signal corresponding to a detection result for each group among the first control signal and the second control signal to each of the pixel circuits belonging to the group. The electro-optical device according to 1. The drive control means includes
First signal generating means for generating the first control signal, second signal generating means for generating the second control signal, a plurality of selection circuits each corresponding to one group, and detection by the detection means Instructing either one of the first control signal and the second control signal to each of the plurality of selection circuits according to a result,
Each of the selection circuits selects a control signal designated by the instruction means from among the first control signal generated by the first signal generation means and the second control signal generated by the second signal generation means, and the selection circuit The electro-optical device according to claim 10, wherein the electro-optical device outputs to each pixel circuit of a group corresponding to. The plurality of selection circuits are divided into blocks every predetermined number,
The electro-optical device according to claim 11, wherein the instruction unit gives a common instruction to each selection circuit belonging to one block.   An electronic apparatus comprising the electro-optical device according to any one of claims 1 to 12. Electricity for displaying an image by a plurality of pixel circuits each including an electro-optical element driven to a gradation corresponding to a data signal and a period control unit for controlling a period during which the electro-optical element is driven based on a control signal A method for driving an optical device comprising:
While supplying a data signal to each of the plurality of pixel circuits every frame period,
A change in an image displayed by the plurality of pixel circuits is detected, and each pixel circuit corresponding to the area in which the change is detected has an electro-optic element in a driving period of a predetermined time length in one frame period. While outputting a first control signal instructing driving and instructing to stop driving in the remaining period, each pixel circuit corresponding to a region where no change in the image is detected has a waveform of the first control signal. A driving method of an electro-optical device that outputs different second control signals. Electricity for displaying an image by a plurality of pixel circuits each including an electro-optical element driven to a gradation corresponding to a data signal and a period control unit for controlling a period during which the electro-optical element is driven based on a control signal A circuit for driving an optical device,
Driving means for supplying a data signal to each of the plurality of pixel circuits every frame period;
Each pixel circuit corresponding to a region in which the change is detected by a detecting unit that detects a change in an image displayed by the plurality of pixel circuits is provided in the driving period of a predetermined time length in one frame period. While outputting the first control signal for instructing the driving of the optical element and instructing the stop of the driving in the remaining period, each pixel circuit corresponding to the region in which no change is detected by the detecting means is provided in the first control signal. And a drive control means for outputting a second control signal having a waveform different from that of the signal.

Images