JP2007147867A - Self emitting display device, light emitting condition controller, light emitting condition control method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a proper technique capable of effectively suppressing an overcurrent flowing to a display panel. <P>SOLUTION: A light emission condition controller which freely variably controls peak luminance of the display panel per frame is mounted with: (a) an average gray value calculation part which calculates an average gray value of an image signal per frame; (b) a gray scale change detecting part which detects appearance of a frame of which the gray scale has been largely changed from that of the preceding frame, on the basis of a difference between an average gray value of the preceding frame and that of the current frame; (c) a light emission condition control part which sets the immediately preceding frame as a reference frame in response to detecting the frame of which the gray scale has been largely changed, and controls a light emission condition of the display panel so that the peak luminance of display frames within a prescribed period following the reference frame is gradually approximated from a peak luminance value of the reference frame to a peak luminance value of each following frame; and (d) a frame delay part which delays the image signal so that a control of the light emission condition control part agrees with a phase of the image signal outputted to the display panel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The invention described in this specification relates to a technique for suppressing an overcurrent phenomenon (a phenomenon in which a current suddenly changes) accompanying screen switching.
The invention proposed by the inventors has aspects such as a self-luminous display device, a light emission condition control device, a light emission condition control method, and a program.

The organic EL display not only has excellent wide viewing angle characteristics, response speed, wide color reproducibility range, and high contrast performance, but also allows the display panel itself to be formed thin. Because of these advantages, organic EL displays are attracting attention as the most promising candidates for next-generation flat panel displays.
On the other hand, in order to use the organic EL display for viewing television programs, it is necessary to further extend the product life.

One of the technical issues required to realize this requirement is to suppress the overcurrent phenomenon that accompanies scene switching.
This overcurrent phenomenon occurs due to a current difference between a large current that flows when the entire screen is bright and a small current that flows when the entire screen is dark or only part of the screen is bright.

That is, the overcurrent phenomenon occurs when the entire screen suddenly switches from a bright screen to a dark screen, or vice versa. The overcurrent gives a sudden load to the power source of the organic EL panel. Therefore, for stable driving of the display panel, it is necessary to perform control so that an abrupt load is not applied to the power supply as much as possible.
However, as far as the inventors know, no technology for realizing overcurrent suppression has been proposed with respect to flat panel drive technology in which self-emitting elements are arranged in a matrix.

For reference, examples of existing technologies related to peak luminance control are listed.
For example, Patent Document 1 discloses a technique for determining the luminance of one pixel based on the average luminance obtained for a plurality of subframes.
Further, for example, Patent Document 2 discloses a method of dividing the light emission period of one frame into a plurality of subframe periods and controlling the light emission luminance in units of subframes.
Further, for example, Patent Document 3 discloses a method of limiting the current flowing through each light emitting element in accordance with the total current value flowing through the plurality of light emitting elements.
JP 2003-015605 A JP 2001-343941 A JP 2002-132218 A

  Although all of Patent Documents 1 to 3 can be used for controlling the peak luminance, the phase relationship between the peak luminance and the current to be controlled, the timing, and the like are not described. For this reason, the overcurrent accompanying screen switching cannot be effectively suppressed.

Therefore, the inventors propose a technical method that can effectively suppress the overcurrent phenomenon that accompanies screen switching.
That is, the gradation change with respect to the previous frame is large based on the processing function for calculating the average gradation value of the video signal for each frame and the difference between the average gradation value of the previous frame and the average gradation value of the current frame. A processing function that detects the appearance of a frame and when detecting a frame with a large gradation change, the previous frame is set as a reference frame, and the peak luminance of the display frame within a predetermined period after the reference frame is the peak luminance of the reference frame. The processing function that controls the light emission conditions of the display panel so that it gradually approaches the peak luminance value of each subsequent frame from the value, and the video so that the control of the light emission conditions and the phase of the video signal output to the display panel match We propose a method for executing a processing function for delaying a signal.

  In the invention proposed by the inventors, the peak luminance of the display panel within a predetermined period from detection of screen switching is controlled so as to gradually approach the peak luminance value of each subsequent frame from the peak luminance value of the reference frame. The As a result, it is possible to change the current change so as to be gentle even when the screen is switched with a luminance change that would normally cause overcurrent. As a result, the overcurrent phenomenon can be effectively suppressed and stable current driving of the display panel can be realized.

Hereinafter, a self-luminous display device will be described using an organic EL panel module equipped with a processing function according to the invention as an example.
In addition, the well-known or well-known technique of the said technical field is applied to the part which is not specifically illustrated or described in this specification.
Moreover, the form example demonstrated below is one form example of invention, Comprising: It is not limited to these.

(A) Adjustment of peak luminance The peak luminance of the display panel can be adjusted by controlling the output voltage (output current) or the light emission time length applied to the display element when the maximum data is input.
FIG. 1A shows the relationship between the output voltage and the light emission luminance, and FIG. 1B shows the relationship between the light emission time and the light emission luminance. Note that FIG. 1B illustrates a case where a linear relationship is established between the light emission time and the light emission luminance.

Here, the peak luminance of the display panel is given by the product S of the maximum output voltage Vmax (maximum output current Imax) applied to the display element when the maximum data is input and the light emission time.
Therefore, if the light emission time or the maximum output voltage Vmax (maximum output current Imax) is individually variably controlled, the peak luminance of the display panel can be variably controlled while maintaining the gradation information.

(B) Structural Example of Organic EL Panel Next, a structural example of an organic EL panel module that enables variable control of peak luminance will be described.
FIG. 2 shows a structural example of the organic EL panel module 1. The organic EL panel module 1 includes a light emitting region 3A (a region where organic EL elements are arranged in a matrix) and a panel drive circuit that controls image display.
The panel drive circuit includes a data driver 5, a maximum output voltage control driver 7A, a gate scan driver 7B, and a lighting time control gate driver 7C. The panel drive circuit is formed in the periphery of the light emitting region 3A.

The organic EL element 3B corresponding to each pixel and its drive circuit (pixel drive circuit) 3C are disposed at the intersection of the data line 3D and the scanning line 3E. The pixel drive circuit 3C includes a data switch element T1, a capacitor C1, a current drive element T2, and a lighting switch element T3.
Among these, the data switch element T1 is used to control the timing of taking in the voltage value given through the data line 3D. The capture timing is given line-sequentially through the scanning line 3E.

The capacitor C1 is used to hold the acquired voltage value for one frame. By using the capacitor C1, frame sequential driving is realized.
The current driving element T2 is used to supply a current corresponding to the voltage value of the capacitor C1 to the organic EL element 3B. The drive current is supplied through the current supply line 3F. The maximum output voltage Vmax is applied to the current supply line 3F through the maximum output voltage control driver 7A.

The lighting switch element T3 is used to control the supply of drive current to the organic EL element 3B. The lighting switch element T3 is arranged in series with respect to the drive current supply path. While the lighting switch element T3 is closed, the organic EL element 3B is lit. On the other hand, the organic EL element 3B is turned off while the lighting switch element T3 is open.
The lighting control line 3G supplies a duty pulse (FIG. 3B) for controlling the opening / closing operation of the lighting switch element T3. Note that FIG. 3A illustrates one frame period as a reference period.

Here, variable control of the voltage applied to the current supply line 3F is executed by the maximum output voltage control driver 7A. Further, the light emission time variable control is executed by the lighting time control gate driver 7C. These driver control signals are supplied from a light emission condition control device to be described later.
When the peak luminance is controlled by the light emission time length, the maximum output voltage control driver 7A supplies a fixed voltage for all frames. On the other hand, when the peak luminance is controlled by the maximum output voltage Vmax, the lighting time control gate driver 7C supplies duty pulses having a fixed ratio for all frames.

FIG. 4 shows a structural example of the organic EL panel module 1 on which the light emitting region 3A in which the pixel driving circuit 3C is formed is mounted. In the case of FIG. 4, the light emission condition control device 11 is mounted as a part of the timing generator 9.
The peripheral circuit (panel drive circuit) of the light emitting region 3A may be mounted on the panel substrate as a semiconductor integrated circuit, or may be directly formed on the panel substrate using a semiconductor process.

(C) Example of Light-Emitting Condition Control Device Hereinafter, an example of the light-emitting condition control device 11 (FIG. 4) that can effectively suppress overcurrent associated with scene switching will be described.

(C-1) Form example 1
(A) Device Configuration FIG. 5 shows an example of a light emission condition control device that suppresses overcurrent by variable control of the light emission time length.
The light emission condition control device 11 includes an average gradation value calculation unit 13, a gradation change detection unit 15, a duty ratio control unit 17, and a frame delay unit 19.
The average gradation value calculation unit 13 is a processing device that calculates the average gradation value APLn of the video signal for each frame. Here, the subscript n means time (for example, frame number). FIG. 6 shows an example of calculating the average gradation value APLn.

The gradation change detection unit 15 is a processing device that detects the appearance of a frame having a large gradation change with respect to the previous frame based on the difference between the average gradation value of the previous frame and the average gradation value of the current frame. .
Specifically, when the difference calculated as a result of detection is equal to or greater than threshold value B, gradation change detection unit 15 sets the peak luminance control mode to the on state. On the other hand, when the difference calculated as a result of the detection is less than the threshold value B, the gradation change detection unit 15 controls the peak luminance control mode to be in the off state.

Here, when the threshold value B is set to a very small value, the peak luminance is controlled even with a slight luminance change. That is, it is not preferable because the control is executed even when there is no possibility that an overcurrent flows.
On the other hand, if the threshold value B is set to a very large value, the peak luminance control is not executed even if a considerably large current change occurs, and the effect of suppressing the overcurrent cannot be fully exhibited. Therefore, the magnitude of the threshold value B needs to be set to an appropriate value in consideration of the control result.

The duty ratio controller 17 calculates an average gradation value OTn for determining peak luminance according to the state of the control mode, and controls the light emission time length of the organic EL panel.
Specifically, the gradation change detection unit 15 sets the immediately preceding frame as a reference frame when the control mode is on (when a frame with a large gradation change is detected), and within a predetermined period after the reference frame. The light emission time length (light emission condition) of the organic EL panel is controlled so that the peak luminance of the display frame gradually approaches the average gradation value of each subsequent frame with the average gradation value of the reference frame. The duty ratio control unit 17 functions as a “light emission condition control unit” in the claims.
A method for calculating the average gradation value OTn for determining the peak luminance will be described later.

Hereinafter, a period until the peak luminance is changed from the reference frame to the peak luminance of the current frame is referred to as a “buffer period”. The buffer period is set from the viewpoint of the response speed of the screen. For example, it is set in the range of 2 to 10 frames. However, it is possible to set a period of 10 frames or more depending on the display program (content).
Further, the duty ratio control unit 17 performs the above determination processing in synchronization with the vertical synchronization signal Vsync, and emits light that gives the output peak luminance of the next frame based on the calculated average luminance value OTn for determining peak luminance. The time length (ie, duty ratio) is determined.

The determined duty ratio is output to the organic EL panel module 1 as a duty ratio control signal (peak luminance control signal).
The duty ratio control signal (peak luminance control signal) is given by the ratio (= OTn / APLn) of the average gradation value OTn for determining peak luminance to the average gradation value APLn of the next frame.
Therefore, the peak luminance of the output frame is OTn / APLn with respect to the peak luminance of the input frame.
Controlled twice.

The frame delay unit 19 is a buffer memory that delays the video signal so that the control of the duty ratio control unit 17 and the phase of the video signal output to the organic EL panel coincide. The delay time is arbitrary.
FIG. 7 shows the phase relationship between the input and output frames. FIG. 7A shows the frame number (phase) of the video signal VS. FIG. 7B is a diagram showing the number (phase) of image data input to the frame delay unit 19.

FIG. 7C is a diagram showing the number (phase) of the average gradation value APL output from the average gradation value calculation unit 13. FIG. 7D is a diagram showing the number (phase) of image data output from the frame delay unit 19.
As can be seen by comparing FIGS. 7B and 7D, the frame delay unit 19 delays the image data by one frame. Therefore, as shown in FIGS. 7C and 7D, synchronization between the average gradation value APL and the output phase of the frame delay unit 19 is ensured. Strictly speaking, the output phase of the frame delay unit 19 is required to be synchronized with the duty ratio control signal.

(B) Flow of Processing Operation (b-1) Outline FIG. 8 shows an outline of the processing operation executed by the light emission condition control device 11 described above.
The light emission condition control device 11 generates an average gradation value APLn (FIG. 7C) of each frame (S1), and an average gradation value APLn-1 of the previous frame.
And a difference between the average gradation value APLn of the current frame and the threshold value B (S2). The threshold value B is given by a gradation difference that allows overcurrent to flow.
When a positive result is obtained, the light emission condition control device 11 controls the peak luminance control function to be in an on state (S3). On the other hand, if a negative result is obtained, the light emission condition control device 11 controls the peak luminance control function to be in an off state (S4).

Thereafter, the light emission condition control device 11 generates an average gradation value OTn for peak luminance control according to each control mode (S5). Incidentally, when the peak luminance control function is on, the average gradation value OTn for determining the peak luminance is the average gradation value APLn of the previous frame in which the scene change is detected.
Are generated so as to gradually approach the average gradation value of each subsequent frame. On the other hand, when the peak luminance control function is in the off state, the average gradation value OTn for determining the peak luminance is always the average gradation value APLn of the current frame.
Set to

When the average gradation value OTn for determining the peak luminance is generated, the light emission condition control device 11 calculates the average gradation value calculated for the display frame (the frame corresponding to the image data output from the frame delay unit 19). APLn
The ratio is obtained, and this value is output to the organic EL panel module 1 as a duty ratio control signal (peak luminance control signal) (S6).
The above is the outline of peak luminance control for suppressing overcurrent.

(B-2) Details FIG. 9 shows detailed processing contents after the average gradation value APL of each frame is calculated.
As described above, the light-emission condition control device 11 uses the average gradation value APLn-1 of the previous frame and the average gradation value APLn of the current frame.
Is compared with the threshold value B (S11).
Here, when the difference between the average gradation values is small (when a negative result is obtained), the light emission condition control device 11 uses the average gradation value APLn of the current frame as the average gradation value OTn for determining the peak luminance. Set (S12).

Thereafter, the light emission condition control device 11 sets the peak luminance control mode to OFF (S13).
Next, the light emission condition control device 11 sets “1” (= OTn / APLn) as the peak luminance control value.
) And output to the organic EL panel module 1 as a duty ratio control signal (peak luminance control signal). In this case, the peak luminance of the output frame matches the original peak luminance of the input frame.

On the other hand, when the difference between the average gradation values is large (when a positive result is obtained), the light emission condition control device 11 determines whether or not the peak luminance control mode is off (S15).
Here, if a positive result is obtained, the light emission condition control device 11 proceeds to step S16. An affirmative result is obtained when a large gradation difference appears at the first activation or when peak luminance control has already been completed.

In step S16, the light emission condition control device 11 sets the peak luminance control mode to ON, and simultaneously sets the average gradation value APLn-1 of the previous frame as the average gradation value APL of the reference frame. In addition, the light emission condition control device 11 sets the processing count c within the buffer period (the number of frames d) set to “1” in order to moderately control the change in peak luminance.
Note that the buffer period is provided not only to moderate the change in peak luminance, but also to prevent the original video output from being affected by the continued control of peak luminance.

When the necessary setting is completed, the light emission condition control device 11 proceeds to step S17, and calculates the average gradation value OTn for determining the peak luminance based on the following equation. That is, the calculation is performed so that the peak luminance of the reference frame and the peak luminance of the output frame are internally divided at an internal ratio determined by the processing count c.
OTn = (APL × (dc) + APLn
× c) / d

For example, when the number of frames d giving the buffer period is 3, the average gradation value OTn when the processing count c is “1” is given by (APL × 2 + APLn) / 3.
Thereafter, the light emission condition control device 11 calculates a control value of peak luminance based on OTn / APLn, and outputs it to the organic EL panel module 1 as a duty ratio control signal (peak luminance control signal) (S14).

By the way, when a negative result is obtained in process S15, the light emission condition control apparatus 11 proceeds to process S18. A negative result is obtained when the peak luminance control mode is on and peak luminance control has already been started.
At this time, the light emission condition control device 11 determines whether or not the peak luminance control period has ended. That is, it is determined whether or not the buffer period has ended. Specifically, it is determined whether or not the parameter c exceeds the maximum value cmax (the number of frames d giving the buffer period). That is, it is determined whether c> d.

If an affirmative result is obtained, the average gradation value APLn of the corresponding frame is set as the average gradation value OTn for determining the peak luminance as in the case described above (S12).
Thereafter, the light emission condition control device 11 uses the average gradation value APLn of the corresponding frame as the average gradation value OTn for determining the peak luminance.
And set the peak brightness control mode to off. As a result, the control value of the peak luminance is “1” (= OTn / APLn), and the output peak luminance matches the peak luminance of the input video signal. .

On the other hand, if a negative result is obtained in step S18, the light emission condition control device 11 updates the value of the parameter c to c + 1 (S19), and then calculates an average gradation value OTn for determining peak luminance. .
For example, when updated to c = 2, the average gradation value OTn is given by (APL + APLn × 2) / 3.
As a result, the peak brightness control value OTn / APLn calculated in step S14 changes to a value closer to the actual brightness of the current frame than the reference frame, as compared with the case of c = 1.
When the number of frames d giving the buffer period is 3 and c = 3, the peak luminance control value calculated in step S14 is OTn / APLn is "1", and the peak luminance converges to the actual luminance of the current frame. .

FIG. 10 shows how the average luminance value OTn for determining the peak luminance is switched at the time point t1 by the peak luminance control process.
10A to 10D correspond to FIGS. 7A to 7D. FIG. 10E shows the average gradation value OTn calculated for determining the peak luminance. However, in FIG. 10E, the average gradation value OTn in the period when the control mode is OFF is represented by the average gradation value APL of each frame.
In FIG. 10, the ON state of the control mode continues for at least 5 frames.

FIG. 11 shows an example of how the peak luminance corresponding to the video signal changes by controlling the peak luminance. FIG. 11 shows the case where the number of frames d giving the buffer period is three.
FIG. 11A shows changes in actual peak luminance (indicated by black circles) when the peak luminance (indicated by white circles) of the input frame changes stepwise at a certain step.

In the case of this example, it changes by 1/3 of the original luminance change to the next frame of the reference frame, and changes by 2/3 of the original luminance change to the second frame.
This means that the luminance change (current change) that normally occurs in one frame period is averaged over two frames.

FIG. 11B shows a change in actual peak luminance (indicated by a black circle) when a large change in peak luminance (indicated by a white circle) of the input video signal continues for about three frames at a certain step.
In this case as well, the next frame after the reference frame changes by one third of the original luminance change. The second frame from the reference frame changes by two thirds of the luminance change that originally occurs between the reference frame and the second frame. It is only the difference from the reference frame.
Then, in the third frame from the reference frame, the frame converges to the original peak luminance.

FIG. 11C shows a control example in the case where the peak luminance rapidly decreases, unlike the two examples described above.
Also in this case, a large change in peak luminance that would have occurred if the peak luminance (indicated by white circles) of the input video signal is followed is averaged over a period of three frames.
In addition, each example illustrates an example in which the change in peak luminance after the buffer period is small. For this reason, in FIG. 11, the peak luminance of the input frame and the peak luminance of the output frame (shown by black circles) match in any case. However, when the peak luminance of the input frame changes greatly thereafter, the same operation is repeated again.

(C) Realized Effect As described above, the average gradation value of each frame is calculated from the input video signal, and when the change of the average gradation value with respect to the previous frame is large, the previous frame is set as the reference frame. By adopting a mechanism that controls the peak luminance of the display frame so that it gradually approaches the peak luminance value of each subsequent frame from the peak luminance value of the reference frame, there is a possibility that overcurrent may flow. Even when the screen changes with a change in luminance, the current change can be changed gradually.

As a result, the overcurrent phenomenon can be effectively suppressed and stable current driving of the display panel can be realized.
Note that the above-described variable control function of peak luminance has a small calculation load even when implemented by software processing, and can be implemented by a very small circuit even when implemented by an integrated circuit. It is advantageous for mounting on a panel module.

(C-2) Embodiment 2
FIG. 12 shows an example of a light emission condition control device that suppresses overcurrent by variable control of the maximum output voltage Vmax applied to the current supply line 3F. In FIG. 12, the same reference numerals are given to the portions corresponding to Embodiment 1 (FIG. 5).

  The light emission condition control device 11 shown in FIG. 14 includes an average gradation value calculation unit 13, a gradation change detection unit 15, a frame delay unit 19, and a maximum output voltage control unit 21. Except for the maximum output voltage control unit 21, the configuration is the same as that of the first embodiment. In the case of this example, the maximum output voltage control unit 21 functions as a “light emission condition control unit” in the claims.

  In other words, the peak luminance control value calculated by the gradation change detection unit 15 is given to the maximum output voltage control unit 21. Then, the maximum output voltage control unit 21 generates a maximum reference voltage control signal at a timing synchronized with the vertical synchronization signal Vsync of the input video signal, and supplies this to the organic EL panel module 1 (maximum output voltage control driver 7A). To do.

However, as shown in FIG. 1A, when the light emission luminance of the display element is not proportional to the maximum output voltage, a value varied in consideration of these is output as the maximum output voltage control signal.
As described above, the same effect as in the first embodiment can be realized even if a method of variably controlling the maximum output voltage Vmax while keeping the light emission time within one frame period constant.

(D) Other Embodiments (a) In the embodiment described above, the organic EL panel module 1 has been described as having both the maximum output voltage control driver 7A and the lighting time control gate driver 7C.
However, the variable control function of peak luminance can be realized by variably controlling either the light emission time or the maximum output voltage. Therefore, when adopting a method for variably controlling the light emission time, a configuration without the maximum output voltage control driver 7A is adopted, and when adopting a method for variably controlling the maximum output voltage, a gate driver for lighting time control. You may employ | adopt the structure which does not mount 7C.

(B) In the embodiment described above, the case where the peak luminance is variably controlled by variably controlling either one of the light emission time and the maximum output voltage has been described. It is also possible to reduce the luminance.
(C) Although the organic EL display panel has been described in the above-described embodiments, it can also be applied to an inorganic EL display panel.

(D) In the above-described embodiment, the case where the light emission condition control device 11 is mounted on the organic EL display panel has been described.
However, this organic EL display panel and other display devices may be in the form of a single product or may be mounted as part of another image processing device. For example, video cameras, digital cameras and other imaging devices (including not only camera units but also those integrated with a recording device), information processing terminals (portable computers, mobile phones, portable game machines) , Electronic notebook, etc.) and display devices for game machines.

(E) In the above-described embodiment, the case where the light emission condition control device 11 is mounted on the organic EL display panel has been described.
However, the light emission condition control device 11 may be mounted on the image processing device side that supplies the input video signal to the organic EL display panel or other display device. In this case, a method of supplying duty pulses and voltage values from the image processing device to the display device may be adopted, or a method of giving information indicating these values from the image processing device to the display device may be adopted. .

(F) In the above-described embodiment, the light emission condition control device 11 has been described from the viewpoint of the functional configuration. Needless to say, an equivalent function can be realized as hardware or software.
Further, not only all of these processing functions are realized by hardware or software, but some of them may be realized by using hardware or software. That is, a combination of hardware and software may be used.
(G) Various modifications can be considered for the above-described embodiments within the scope of the gist of the invention. Various modifications and applications created or combined based on the description of the present specification are also conceivable.

It is a figure explaining the relationship between light emission time and light emission luminance, and the relationship between a maximum output voltage and light emission luminance. It is a figure which shows the structural example of an organic electroluminescent panel module. It is a figure which shows the example of a duty pulse which controls light emission time length. It is a figure which shows the structural example of an organic electroluminescent panel module. It is a figure which shows the example 1 of a light emission condition control apparatus. It is a figure which shows the example of calculation of an average gradation value. It is a figure explaining the phase synchronization by a frame delay part. It is a figure which shows the schematic example of the processing operation which a light emission condition control apparatus performs. It is a figure which shows the detailed example of the processing operation which a light emission condition control apparatus performs. It is a figure which shows the example of an output of the average gradation value for peak luminance control. It is a figure which shows the example of a luminance change by peak luminance control. It is a figure which shows the example 2 of a light emission condition control apparatus.

Explanation of symbols

1 Organic EL Panel Module 3A Light Emitting Area 5 Data Driver 7A Maximum Output Voltage Control Driver 7A
7B Gate scan driver 7C Gate driver for lighting time control 9 Timing generator 11 Light emission condition control device 13 Average gradation value calculation unit 15 Gradation change detection unit 17 Duty ratio control unit 19 Frame delay unit 21 Maximum output voltage control unit

Claims (7)

In a self-luminous display device capable of variably controlling the peak luminance of the display panel in units of one frame,
An average gradation value calculating unit for calculating an average gradation value of the video signal for each frame;
A gradation change detection unit that detects the appearance of a frame with a large gradation change relative to the previous frame based on the difference between the average gradation value of the previous frame and the average gradation value of the current frame;
When a frame with a large gradation change is detected, the previous frame is set as the reference frame, and the peak luminance of the display frame within the predetermined period after the reference frame is the peak luminance value of each frame that follows the peak luminance value of the reference frame. A light emission condition control unit for controlling the light emission conditions of the display panel so as to gradually approach
A self-luminous display device comprising: a frame delay unit that delays the video signal so that the control by the light emission condition control unit and the phase of the video signal output to the display panel coincide with each other. The self-luminous display device according to claim 1,
The light emission condition control unit variably controls the light emission time length of the display panel within one frame period. The self-luminous display device according to claim 1,
The light emitting condition control unit variably controls a maximum value of a current value that can be applied to a light emitting element according to an image data value in units of frames. The self-luminous display device according to claim 1,
The self-luminous display device, wherein the light emission condition control unit cancels the control of the peak luminance when a frame having a small gradation change relative to the previous frame appears even during a predetermined period after the reference frame. In the light emission condition control device that variably controls the peak luminance of the display panel in units of one frame,
An average gradation value calculating unit for calculating an average gradation value of the video signal for each frame;
A gradation change detection unit that detects the appearance of a frame with a large gradation change relative to the previous frame based on the difference between the average gradation value of the previous frame and the average gradation value of the current frame;
When a frame with a large gradation change is detected, the previous frame is set as the reference frame, and the peak luminance of the display frame within the predetermined period after the reference frame is the peak luminance value of each frame that follows the peak luminance value of the reference frame. A light emission condition control unit for controlling the light emission conditions of the display panel so as to gradually approach
A light emission condition control apparatus comprising: a frame delay unit that delays the video signal so that the phase of the video signal output to the display panel matches the control by the light emission condition control unit. In the light emission condition control method for variably controlling the peak luminance of the display panel in units of one frame,
A process of calculating an average gradation value of the video signal for each frame;
A process of detecting the appearance of a frame with a large gradation change relative to the previous frame based on the difference between the average gradation value of the previous frame and the average gradation value of the current frame;
When a frame with a large gradation change is detected, the previous frame is set as the reference frame, and the peak luminance of the display frame within the predetermined period after the reference frame is the peak luminance value of each frame that follows the peak luminance value of the reference frame. Processing to control the lighting conditions of the display panel so as to gradually approach
A light emission condition control method comprising: controlling the light emission condition and processing for delaying the video signal so that the phases of the video signals output to the display panel coincide with each other. A computer that variably controls the peak brightness of the display panel in units of one frame.
A process of calculating an average gradation value of the video signal for each frame;
A process of detecting the appearance of a frame with a large gradation change relative to the previous frame based on the difference between the average gradation value of the previous frame and the average gradation value of the current frame;
When a frame with a large gradation change is detected, the previous frame is set as the reference frame, and the peak luminance of the display frame within the predetermined period after the reference frame is the peak luminance value of each frame that follows the peak luminance value of the reference frame. Processing to control the lighting conditions of the display panel so as to gradually approach
A program for executing the control of the light emission condition and the process of delaying the video signal so that the phase of the video signal output to the display panel matches.

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