JP2007240799A - Spontaneous light emission display device, white balance adjusting device, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust white balance without any dedicated tool. <P>SOLUTION: A spontaneous light emission display device comprises a display panel which has dummy pixels by basic light emission colors arranged outside an effective display area, a dummy pixel data determination section which supplies gray scale values for light emission characteristic detection to the respective dummy pixels by the basic light emission colors when the white balance is automatically adjusted, a luminance detection sensor which detects light emission luminances of the dummy pixels by the basic light emission colors when the white balance is automatically adjusted, a luminance characteristic detection section which detects gamma characteristics relating to the light emission luminances of the dummy pixels by the basic light emission colors based upon the light emission luminances detected by the basic light emission colors, a gamma setting section which updates gamma conversion tables corresponding to the respective basic light emission colors so that the detected gamma characteristics by the basic light emission colors meet proper white balance, and a gamma conversion section which gamma-converts an input video signal by referring to the gamma conversion table. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The invention described in this specification relates to a white balance automatic adjustment technique.
The invention proposed by the inventors has aspects such as a self-luminous display device, a white balance adjustment device, and a program.

Flat panel displays are widely used in products such as computer displays, portable terminals, and televisions. Currently, many liquid crystal display panels are mainly used. However, the narrow viewing angle and slow response speed continue to be pointed out.
On the other hand, an organic EL display formed of a self-luminous element can overcome the above-described viewing angle and responsiveness problems, and can achieve a thin form, high brightness, and high contrast that do not require a backlight. Therefore, it is expected as a next-generation display device that replaces the liquid crystal display.

By the way, it is generally known that organic EL elements and other self-light-emitting elements have a property of deteriorating depending on the light emission amount and the light emission time.
On the other hand, the content of the image displayed on the display is not uniform. For this reason, the deterioration of the self-luminous element is likely to proceed partially. For example, the self-light-emitting element in the time display area (fixed display area) progresses more rapidly than the self-light-emitting elements in other display areas (moving image display areas).
The luminance of the self-luminous element that has deteriorated is relatively lowered as compared with the luminance of other display areas. In general, this phenomenon is called “burn-in”. Hereinafter, partial deterioration of the self-luminous element is referred to as “burn-in”.

In addition, when a plurality of types of self-luminous elements are used for each basic emission color, or when a light-emitting element that can generate a plurality of types of basic emission colors is used, the deterioration characteristics of the respective emission colors often do not match.
In this case, in the “burn-in” portion, a phenomenon occurs in which the white balance is shifted and the color appears to be colored or dark.
In order to maintain a good image quality in which such a color shift phenomenon is not perceived, it is necessary to suppress or improve the burn-in phenomenon.
JP 2000-356981 A

However, many of the existing inventions mainly focus on extending the light emission lifetime from the viewpoint of the material constituting the light emitting element and the signal processing, and the occurrence of the color shift phenomenon cannot be solved in principle.
In addition, processing for adjusting white balance may be executed as part of the manufacturing process, but a special jig for generating a special drive waveform or the like is required.

  Therefore, the inventors propose a mechanism that can autonomously adjust the white balance deviation. It is assumed that dummy pixels for each basic light emission color and a luminance detection sensor for detecting the light emission luminance for each basic light emission color are arranged outside the effective display area.

(A) Mechanism 1
As one mechanism, the inventors propose the adoption of the processing function unit shown below.
(A) Dummy pixel data determination processing for providing a gradation value for detecting the light emission characteristics to each dummy pixel for each basic light emission color during automatic white balance adjustment (b) Based on the light emission luminance detected for each basic light emission color, Luminance characteristic detection processing for detecting the gamma characteristic related to the light emission luminance of the dummy pixel for each basic light emission color (c) Update the gamma conversion table corresponding to each basic light emission color so that the detected gamma characteristic satisfies an appropriate white balance. Gamma setting processing (d) Gamma conversion processing for gamma converting the input video signal with reference to the gamma conversion table

(B) Mechanism 2
As one mechanism, the inventors propose the adoption of the processing function unit shown below.
(A) Dummy pixel data determination processing for providing a gradation value for detecting the light emission characteristics to each dummy pixel for each basic light emission color during automatic white balance adjustment (b) Based on the light emission luminance detected for each basic light emission color, Luminance characteristic detection processing for detecting the gamma characteristic related to the emission luminance of the dummy pixel for each basic emission color (c) The data line driving unit corresponding to each basic emission color is given so that the detected gamma characteristic satisfies an appropriate white balance. Driver reference voltage calculation process for calculating the reference voltage value (d) Driver voltage adjustment process for supplying the calculated reference voltage value or the corresponding reference voltage to the data line driver

  According to the invention proposed by the inventors, the white balance can be corrected to an appropriate state without using a dedicated jig. As a result, it is possible to suppress or improve the coloring phenomenon caused by the loss of white balance.

Hereinafter, embodiments of an organic EL display device equipped with the white balance adjustment function according to the invention will be described.
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) Form example 1
(A) Schematic Configuration FIG. 1 shows a system configuration example of an organic EL display device. The organic EL display device 1 includes an organic EL panel module 3 and a gamma adjustment unit 5.

(B) Configuration of Organic EL Panel Module FIG. 2 shows a planar structure example of the organic EL panel module 3. The organic EL panel module 3 includes an effective display area 31, a dummy pixel area 33, a luminance detection sensor, a drive circuit, and other peripheral circuits.

  The dummy pixel region 33 is a gamma characteristic detection region of the organic EL element, and is disposed outside the effective display region 31. Note that a method of detecting the gamma characteristic of the organic EL element by arranging a light detection sensor in the pixel in the effective display area can be considered, but the pixel structure becomes complicated. Therefore, in this embodiment, the dummy pixel area 33 is arranged separately from the effective display area 31.

The effective display area 31 is formed so that the emitted light can be observed from the outside, whereas the dummy pixel area 33 is formed of an impermeable material housing or the like so that the emitted light cannot be observed from the outside. Covered.
In the case of this embodiment, a plurality of dummy pixels are arranged in the dummy pixel region 33. In the case of FIG. 2, P (natural numbers greater than or equal to 2) dummy pixels are arranged.
Incidentally, the same structure as one pixel on the display arranged in a matrix in the effective display area 31 is adopted for the dummy pixel.

FIG. 3 shows a pixel arrangement example of the effective display area 31 and the dummy pixel area 33. In the case of FIG. 3, the effective display area 31 is from the first line to the Nth line, and the dummy pixel area 33 is the N + 1th line. Accordingly, the data in the dummy pixel region 33 is updated using the blanking period.
In the case of this example, one pixel on the display is composed of three unit light emitting areas corresponding to the basic light emission colors red (R), green (G), and blue (B). In this specification, a unit light emission region corresponding to the basic light emission color is also referred to as a dummy pixel.

The organic EL panel module 3 can be realized by adding only one selection line (gate drive line) to a general display panel. In other words, existing drive circuits (data line drive circuit and selection line drive circuit) can be used for driving the dummy pixels. Therefore, a circuit dedicated to driving the dummy pixels or a large-scale driving circuit is not necessary.
The light emission luminance of these dummy pixels is detected by a luminance detection sensor (not shown).

FIG. 4 shows an arrangement example of the luminance detection sensor 35. The luminance detection sensor 35 is arranged at a ratio of one for one dummy pixel. The luminance detection sensor 35 is disposed so as to face the light emitting surface of the dummy pixel and cover the whole. The dummy pixel is composed of three types of unit light emitting areas. For this reason, the luminance detection sensor 35 performs luminance detection of each emission color in a time division manner.
The luminance detection sensor 35 detects visible light output from the dummy pixel and converts it into an electrical signal.

An arbitrary detection sensor is applied to the light detection element. For example, a visible light sensor composed of an amorphous silicon semiconductor is used.
The light amount information detected as a current value is amplified and converted into a voltage value, and is output to the gamma adjustment unit 5 as a dummy pixel light detection signal.

(B) Configuration of Gamma Adjustment Unit The gamma adjustment unit 5 detects gamma characteristics for each basic emission color based on the dummy pixel detection signal, and gammas the input display signal (tone value) so that the white balance is appropriate. The processing device to convert.
FIG. 5 shows an internal configuration example of the gamma adjustment unit 5. The gamma adjustment unit 5 includes a gamma conversion unit 501, a gamma conversion table 503, a panel drive signal generation unit 505, a luminance characteristic detection unit 507, a gamma setting unit 509, a dummy pixel data determination unit 511, and a dummy pixel data multiplexing unit 513. .

  The gamma conversion unit 501 is a processing device that performs gamma conversion of an input display signal with reference to the gamma conversion table 503. The input display signal after the gamma conversion is output as an adjusted display signal. Note that gamma conversion is executed as gradation conversion of the input display signal (RGB data). The adjusted display signal after conversion reflects the actual light emission luminance characteristic of each pixel constituting the effective display area.

  The gamma conversion table 503 is a storage area or storage device that stores input / output relationships for each basic emission color as table data. Note that the number of input / output relationships can be stored in the number corresponding to all the gradation values, or only some input / output relationships can be stored. For example, when the input gradation value of RGB data is given by 8 bits, all the gradation values are given by 256. Therefore, it is possible to store input / output relationships corresponding to all of them, or to store only some of the input / output relationships. Note that when only a part of input / output relations are stored, the gamma conversion unit 501 interpolates other input / output relations.

The panel drive signal generation unit 505 is a processing device that generates signals necessary for driving the display panel (organic EL panel module 3) (signals corresponding to all pixels in the effective display area) even when there is no input display signal. is there. By mounting this processing device, it is possible to eliminate the need to connect to a dedicated external jig when adjusting the white balance.
The luminance characteristic detection unit 507 is a processing device that detects a gamma characteristic related to the light emission luminance of the dummy pixel based on the light emission luminance detected for each basic light emission color through the luminance detection sensor 35. Since the structure of the dummy pixel is the same as that of each pixel in the effective display area, this detection result indirectly represents the gamma characteristic in the effective display area.

  The gamma setting unit 509 is a processing device that performs processing for calculating a white balance adjustment value (gamma conversion data) based on the detected gamma characteristic and processing for controlling the white balance adjustment processing operation. The gamma setting unit 509 executes processing for registering the calculated adjustment value in the gamma conversion table 503. Also, the gamma setting unit 509 checks whether or not gamma conversion data is registered in the gamma conversion table 503. If the gamma conversion data is not registered, the panel drive signal generation unit 505 and dummy pixel data determination are determined. The operation start of the unit 511 is instructed. This operation start is executed regardless of the presence or absence of the input display signal.

  The dummy pixel data determination unit 511 is a processing device that generates dummy pixel data (RGB data) to be given to the dummy pixels. The dummy pixel data is generated so that the light emission luminance corresponding to the input gradation value can be detected for each basic light emission color. For example, for the red (R) dummy pixel, the dummy pixel data determination unit 511 sequentially generates all the gradation values or a part of the gradation values selected in advance. In addition, the dummy pixel data determination unit 511 sequentially generates all gradation values or some gradation values selected in advance for the green (G) dummy pixel. In addition, the dummy pixel data determination unit 511 sequentially generates all gradation values or a part of gradation values selected in advance for the blue (B) dummy pixel.

  The dummy pixel data multiplexing unit 513 is a processing device that multiplexes dummy pixel data with input display data or a panel drive signal. Specifically, the dummy pixel data multiplexing unit 513 executes a process of multiplexing dummy pixel data at a position corresponding to the (N + 1) th line outside the effective display area.

(C) White Balance Adjustment Operation Hereinafter, the white balance automatic adjustment operation executed in the organic EL display device 1 will be described.
Immediately after the display panel is manufactured, no value is set in the gamma conversion table 503. The gamma setting unit 509 recognizes this state and instructs the panel drive signal generation unit 505 to generate a panel drive signal. The panel drive signal generation unit 505 does not generate a drive signal unless instructed by the gamma setting unit 509.

Next, the gamma setting unit 509 measures gamma characteristics for each basic light emitting area (red (R), green (G), and blue (B)) of the dummy pixel in order to adjust the white balance of the display panel. At this time, the dummy pixel data determination unit 511 sequentially changes the gradation value so that the emission luminance for each gradation value can be measured for each basic emission color.
The dummy pixel data multiplexing unit 513 multiplexes the dummy pixel data generated in this way on the (N + 1) th line corresponding to the external area of the video signal in the effective display area.

At this time, the luminance characteristic detection unit 507 detects the gamma curve shown in FIG. 6 for each basic emission color. FIG. 6 shows a change in detected luminance when the gradation value is changed from 0% to 100% for each basic emission color.
At this stage where the white balance is not adjusted, the detected luminance value of the basic emission color at each gradation value does not satisfy the desired luminance ratio x: y: z.
Therefore, the gamma setting unit 509 calculates the adjustment values a, b, and c so as to satisfy the luminance ratio x: y: z where the detected luminance value between the basic emission colors should be.

That is, adjustment values a, b, and c that satisfy aRa: bGa: cBa = x: y: z are calculated. The adjustment value a is for red (R) data, the adjustment value b is for green (G) data, and the adjustment value c is for blue (B) data.
However, the adjusted RGB data aRa, bGa, and cBa are all calculated so as not to exceed the maximum gradation value. Desirably, the output gradation value bGa for the green (G) data is set to be output up to a predetermined absolute luminance, and this is used as a reference value for the other two-color red (R) data aRa and blue (B). The adjustment values a and c of the data cBa are calculated.

FIG. 7 shows an example of gamma conversion data that makes it possible to adjust the white balance to an appropriate state. FIG. 7 is an example of gamma conversion data when the gradation value of the display signal after gamma conversion is given by 10 bits when the gradation value of the input display signal is given by 8 bits.
Of course, the gamma conversion processing is not limited to the case where the gradation value is converted from 8 bits to 10 bits, and it is only necessary to select the optimum number of bits for the display panel drive system for both input and output. For example, it may be converted into different values having the same number of bits.

(D) Effect By mounting the white balance adjustment function described above, the white balance of the display panel can be adjusted without using a special adjustment jig.
The white balance adjustment process can be executed in parallel with the aging process or the like. For this reason, processing time can be used effectively.

Further, in the case of the white balance adjustment function proposed by the inventors, a necessary adjustment value can be calculated for each gradation value only by giving the initial setting ratio x: y: z. That is, the white balance can be adjusted even if the absolute gradation value cannot be set individually.
In addition, in the case of the white balance adjustment function proposed by the inventors, it is only necessary to mount some simple functional blocks, and it is easy to mount on the display panel.

(B) Embodiment 2
(A) Schematic Configuration FIG. 8 shows another system configuration example of the organic EL display device. The organic EL display device 11 includes an organic EL panel module 13, a gamma adjustment unit 15, and a data line driving unit 17.

(B) Configuration of Organic EL Panel Module As the organic EL panel module 13, a display panel having the same structure as that of Embodiment 1 is used. That is, a display panel in which the dummy pixel area 33 and the luminance detection sensor 35 are arranged outside the effective display area 31 is used.

(C) Configuration of Gamma Adjustment Unit 15 The gamma adjustment unit 15 used in this embodiment detects the gamma characteristic for each basic emission color based on the dummy pixel detection signal, and drives the data lines so that the white balance is appropriate. It functions as a processing device that automatically adjusts the reference voltage Vref of the unit 17.

FIG. 9 shows an internal configuration example of the gamma adjustment unit 15. The gamma adjustment unit 15 includes a panel drive signal generation unit 1501, a luminance characteristic detection unit 1503, a driver reference voltage calculation unit 1505, a dummy pixel data determination unit 1507, a dummy pixel data multiplexing unit 1509, and a driver voltage adjustment unit 1511.
The panel drive signal generation unit 1501 generates a signal (a signal corresponding to all the pixels in the effective display area) necessary for driving the display panel (organic EL panel module 13) even when there is no input display signal. By mounting this processing device, it is possible to eliminate the need to connect to a dedicated external jig when adjusting the white balance.

  The luminance characteristic detection unit 1503 detects a gamma characteristic related to the emission luminance of the dummy pixel based on the emission luminance detected for each basic emission color through the luminance detection sensor 35. Since the structure of the dummy pixel is the same as that of each pixel in the effective display area, this detection result indirectly represents the gamma characteristic in the effective display area.

  The driver reference voltage calculation unit 1505 calculates a reference voltage value Vref to be given to the drive circuit that drives the data line corresponding to each basic emission color so that the detected gamma characteristic for each basic emission color satisfies an appropriate white balance. And processing for controlling the white balance adjustment processing operation.

  The driver reference voltage calculation unit 1505 executes a process of supplying the calculated reference voltage value Vref to the driver voltage adjustment unit 1511. Also, the driver reference voltage calculation unit 1505 checks whether or not the white balance adjusted reference voltage is registered in the driver voltage adjustment unit 1511. If gamma conversion data is not registered, the driver reference voltage calculation unit 1505 generates a panel drive signal. Processing for instructing the operation start of the unit 1501 and the dummy pixel data determination unit 1507 is executed. This operation start is executed regardless of the presence or absence of the input display signal.

  The dummy pixel data determination unit 1507 executes a process of giving a gradation value for detecting a light emission characteristic to each dummy pixel for each basic light emission color when automatic white balance adjustment is executed. Also in this case, the dummy pixel data is generated so that the emission luminance corresponding to the input gradation value can be detected for each basic emission color.

  The dummy pixel data determination unit 1507 sequentially generates all gradation values or a part of gradation values selected in advance for, for example, a red (R) dummy pixel. Further, the dummy pixel data determination unit 1507 sequentially generates all gradation values or a part of gradation values selected in advance for the green (G) dummy pixel. Further, the dummy pixel data determination unit 1507 sequentially generates all gradation values or a part of the gradation values selected in advance for the blue (B) dummy pixel.

  The dummy pixel data multiplexing unit 1509 is a processing device that generates dummy pixel data (RGB data) to be given to the dummy pixels. Specifically, at the time of executing white balance, the dummy pixel data multiplexing unit 1509 executes a process of multiplexing dummy pixel data at a position corresponding to the (N + 1) th line outside the effective display area. Therefore, when the white balance is not executed, the dummy pixel data multiplexing process is not executed.

  The driver voltage adjustment unit 1511 is a processing device that supplies the calculated reference voltage value or the corresponding reference voltage to the data line driving unit (driver) 17. The driver voltage adjustment unit 1511 supplies the initially set reference voltage value or reference voltage until the white balance adjustment operation is executed.

(D) Configuration of Data Line Driver 17 FIG. 10 shows an arrangement example of the data line driver 17. FIG. 10 shows a case where the data line driving unit 17 is formed on the same substrate as the effective display area 31. The data line driving unit 17 can be externally attached to the base of the organic EL panel module 11.

  FIG. 11 shows a schematic configuration of the data line driving unit 17. In the data line driving unit 17 shown in FIG. 11, one D / A conversion circuit 171 is connected to one data line. The data lines here are data lines in RGB data units. In other words, the D / A conversion circuit 171 is one for converting red (R) data, for converting green (G) data, and for converting blue (B) data. Which color the D / A conversion circuit 171 corresponds to depends on the dot pattern on the display. FIG. 11 shows an example in which red (R), green (G), and blue (B) repeatedly appear on one line (on the scanning line).

A wiring pattern 173 that provides a reference voltage Vref is connected to the group of D / A conversion circuits 171. The reference voltage Vref is given from the gamma adjustment unit 15. For example, a group of D / A conversion circuits 171 corresponding to red (R) data has a reference voltage Vref-R.
Are connected to the wiring pattern 173. Similarly, the wiring pattern 173 corresponding to the reference voltage Vref-G is connected to the group of D / A conversion circuits 171 corresponding to the green (G) data. Similarly, a group of D / A conversion circuits 171 corresponding to blue (B) data has a reference voltage Vref-B.
Are connected to the wiring pattern 173.

  In this embodiment, the white voltage is adjusted while maintaining the resolution by individually adjusting the reference voltage applied to the wiring pattern 173. For example, only the luminance range of red (R) color is adjusted independently. By executing this adjustment for all or part of the basic emission colors, the perceptual hue can be moved, and the white balance is adjusted to an appropriate state.

  FIG. 12 shows a basic configuration example of the ladder resistance type D / A conversion circuit 171. FIG. 12 shows a basic circuit called 2R-R type. This indicates that the resistance value at the branch destination is 2R (2 × R), and the overall resistance value is R. In the case of this configuration, the current flowing at each branching in turn from the branch point on the reference power supply (maximum output voltage) side is halved. The branched current flows into the input terminals of the switches S1 to S4 (in the case of 4 bits). The reference power supply corresponds to the above-described reference voltages Vref-R, Vref-G, and Vref-B.

The switches S1 to S4 are on / off controlled by the main switch 175 in accordance with the gradation value (n bits) of each pixel. Each of the switches S1 to S4 applies an inflow current to the operational amplifier 179 when turned on, and allows an inflow current to flow through the ground line when off. As a result, a current corresponding to the gradation value (current sum from each switch) flows into the output resistance r of the operational amplifier. At this time, the voltage appearing at both ends of the output resistor r becomes the output voltage.
FIG. 13 shows changes in the output voltage when the reference voltage Vref is variably controlled. It can be seen that by variably controlling the maximum reference voltage, the output voltage is variably controlled even at the same gradation value.

(E) White Balance Adjustment Operation Hereinafter, the white balance automatic adjustment operation executed in the organic EL display device 11 will be described.
Immediately after the manufacture of the display panel, only the initial value of the reference voltage is set in the driver voltage adjustment unit 111. The driver reference voltage calculation unit 1505 recognizes this state and instructs the panel drive signal generation unit 1501 to generate a panel drive signal. Panel drive signal generation section 1501 does not generate a drive signal unless instructed by driver reference voltage calculation section 1505.

Next, the driver reference voltage calculation unit 1505 measures gamma characteristics for each basic light emitting region (red (R), green (G), and blue (B)) of the dummy pixel in order to adjust the white balance of the display panel. . At this time, the dummy pixel data determination unit 1507 sequentially changes the gradation value so that the emission luminance for each gradation value can be measured for each basic emission color.
The dummy pixel data multiplexing unit 1509 multiplexes the dummy pixel data generated in this way on the (N + 1) th line corresponding to the external area of the video signal in the effective display area.

At this time, the luminance characteristic detection unit 1503 detects the gamma curve shown in FIG. 6 for each basic emission color, as in the first embodiment. FIG. 6 shows the relationship of detected luminance when the gradation value is changed from 0% to 100% for each basic emission color.
At this stage where the white balance is not adjusted, the detected luminance value of the basic emission color at each gradation value does not satisfy the desired luminance ratio x: y: z.
Therefore, the driver reference voltage calculation unit 1505 calculates adjustment values a, b, and c (corresponding reference voltage values Vref) so as to satisfy the luminance ratio x: y: z where the detected luminance value between the basic emission colors should be. To do.

That is, the reference voltage values Vref-R, Vref-G, and Vref-B that satisfy aRa: bGa: cBa = x: y: z are calculated. The reference voltage value Vref-R is for red (R) data, the reference voltage value Vref-G is for green (G) data, and the reference voltage value Vref-B
Is for blue (B) data.
Also in this case, the adjusted reference voltage values Vref-R, Vref-G, and Vref-B are all calculated so as not to exceed the maximum voltage value on the system.

This reference voltage is applied to the D / A conversion circuit 171 of the data line driving unit 17, and the white balance adjustment operation is completed.
FIG. 14 shows a white balance adjustment image. FIG. 14 shows a state where the maximum reference voltage corresponding to each basic emission color is appropriately set.
As a result, even when the input display signal is input to the organic EL panel module 13 without adjustment, the actual light emission luminance corresponding to each basic light emission color is emitted with the white balance adjusted.

(D) Effect With the above-described white balance adjustment function, the white balance of the display panel can be adjusted even when the gamma curve cannot be digitally processed. Of course, no special adjustment jig is required.
The white balance adjustment process can be executed in parallel with the aging process or the like. That is, the processing time can be effectively utilized.

In this case as well, necessary adjustment values can be calculated for each gradation value simply by giving the initial setting ratio x: y: z that defines the white balance. That is, the white balance can be adjusted even if the absolute reference voltage value cannot be set individually.
In addition, in the case of the white balance adjustment function proposed by the inventors, it is only necessary to mount some simple functional blocks, and it is easy to mount on the display panel.

(C) Other Embodiments (a) In the case of the above-described Embodiment 2, the case where the maximum reference voltage of the D / A conversion circuit 171 is set for each basic light emission color has been described.
However, a method of setting the intermediate voltage value used when the D / A conversion circuit 171 converts the gradation value (digital value) into an analog voltage may be adopted. In this case, the white balance can be set in a favorable state for a wider gradation range.

FIG. 15 shows an application example to a ladder resistance type D / A conversion circuit 171. FIG. 15 is a diagram in which parts corresponding to those in FIG. The difference between FIG. 15 and FIG. 12 is that four reference voltage values Vref1 to Vref4 are applied to four intermediate points of the ladder resistor circuit. FIG. 16 shows a white balance adjustment image. As shown in FIG. 16, the reference voltage value corresponding to the intermediate gradation value corresponding to each basic light emission color is appropriately set.
As a result, it is possible to adjust the white balance to a good state for a gradation range wider than that of the second embodiment.

(B) In the above-described embodiment, the case where the white balance adjustment process is executed immediately after the display panel is manufactured has been described.
However, white balance adjustment processing can be executed using the same mechanism during use. However, in this case, it is necessary for the dummy pixels to practically reflect the light emission characteristics of the effective display area when executing the white balance adjustment. Therefore, except when adjusting the white balance, a mechanism for controlling the light emission of each dummy pixel with a gradation value that gives an overall deterioration tendency of the effective display area, for example, an average gradation value of the entire screen may be adopted.

(C) In the above-described embodiment, the case where a plurality of dummy pixels are arranged has been described.
However, only one dummy pixel may be arranged, and light emission control may be performed by giving a plurality of gradation values to the dummy pixel in a time division manner.
(D) In the above-described embodiment, a case has been described in which the dummy pixels are controlled to emit light with a plurality of gradation values in order to detect the gamma characteristic for each basic emission color.
However, if the white balance can be adjusted for a specific gradation value, if the deviation of the white balance can be kept within an allowable range for other gradation values, only the specific gradation value is given to the dummy pixel. The light emission can be controlled. The specific gradation value may be one or more.

(E) In the above-described embodiment, the case where the dummy pixel structure is the same as each pixel in the effective display area has been described.
However, the structure of the dummy pixels is not necessarily the same. For example, the dummy pixel may have a structure in which a luminance detection sensor for detecting the light emission luminance of the organic EL element is built in the pixel circuit. Further, the pixel size of the dummy pixel and the size of the basic light emitting area may be changed.

(F) In the above-described embodiment, the case where the basic light emission colors are three colors of RGB has been described, but the basic light emission color can also be applied to a case where there are four or more colors including complementary colors. In this case, as many dummy pixels as the number of the basic emission colors may be prepared.
(G) In the above-described embodiments, the color generation form of the basic emission color has not been described. However, an organic EL element having a different light emitting element material for each basic emission color may be prepared. It may be used to generate a basic emission color.

(H) Although the organic EL display panel is illustrated as an example of the self-luminous display device in the above-described embodiment, the present invention can also be applied to other self-luminous display devices. For example, the present invention can be applied to FED (field emission display), inorganic EL display panel, LED panel, and the like.

(G) In the above-described embodiment, the white balance automatic adjustment function has been described from a functional aspect. 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.
(H) 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 which shows the schematic structural example of an organic electroluminescent display apparatus. It is a figure which shows the plane structural example of an organic electroluminescent panel module. It is a figure which shows the pixel arrangement example of an organic electroluminescent panel module. It is a figure which shows the example of arrangement | positioning of a dummy pixel and a brightness | luminance detection sensor. It is a figure which shows the internal structural example of a gamma adjustment part. It is a figure explaining the relationship of the detection luminance value according to basic luminescent color. It is a figure which shows the relationship between a gamma gradation value and the calculated deterioration rate. It is a figure which shows the schematic structural example of an organic electroluminescent display apparatus. It is a figure which shows the internal structural example of a gamma adjustment part. It is a figure which shows the plane structural example of an organic electroluminescent panel module. It is a figure which shows the example of schematic structure of a data line drive part. It is a figure which shows the internal structural example of a D / A conversion circuit. It is a figure explaining the relationship between the gradation value and output voltage in the case of carrying out variable control of the reference voltage of a D / A converter circuit. It is a figure which shows the adjustment image of the white balance using a reference voltage. It is a figure which shows the internal structural example of a D / A conversion circuit. It is a figure which shows the adjustment image of the white balance using a reference voltage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic EL display apparatus 5 Gamma adjustment part 11 Organic EL display apparatus 15 Gamma adjustment part 17 Data line drive part 507 Luminance characteristic detection part 509 Gamma setting part 1503 Luminance characteristic detection part 1505 Driver reference voltage calculation part 1511 Driver voltage adjustment part

Claims (9)

A display panel in which dummy pixels for each basic emission color are arranged outside the effective display area;
A dummy pixel data determination unit that gives a gradation value for detecting a light emission characteristic to each dummy pixel for each basic light emission color when automatic white balance adjustment is performed;
A luminance detection sensor that detects the emission luminance of the dummy pixels for each basic emission color when automatic white balance adjustment is performed;
A luminance characteristic detection unit for detecting gamma characteristics related to the emission luminance of the dummy pixels for each basic emission color based on the emission luminance detected for each basic emission color;
A gamma setting unit for updating a gamma conversion table corresponding to each basic emission color so that the detected gamma characteristic satisfies an appropriate white balance;
A self-luminous display device comprising: a gamma conversion unit that performs gamma conversion on an input video signal with reference to a gamma conversion table. The self-luminous display device according to claim 1,
The self-luminous display device, wherein the dummy pixel data determination unit sequentially provides a plurality of gradation values for each basic emission color as gradation values for detecting light emission characteristics. The self-luminous display device according to claim 1,
In the case where a plurality of sets of dummy pixels having a set of basic emission colors are arranged on the display panel, the dummy pixel data determining unit is configured to detect a plurality of sets of gradation values for detecting light emission characteristics for the plurality of sets of dummy pixels. A self-luminous display device characterized in that A display panel in which dummy pixels for each basic emission color are arranged outside the effective display area;
A dummy pixel data determination unit that gives a gradation value for detecting a light emission characteristic to each dummy pixel for each basic light emission color when automatic white balance adjustment is performed;
A luminance detection sensor that detects the emission luminance of the dummy pixels for each basic emission color when automatic white balance adjustment is performed;
A luminance characteristic detection unit for detecting gamma characteristics related to the emission luminance of the dummy pixels for each basic emission color based on the emission luminance detected for each basic emission color;
A driver reference voltage calculation unit that calculates a reference voltage value to be applied to the data line driving unit corresponding to each basic emission color so that the detected gamma characteristic satisfies an appropriate white balance;
A self-luminous display device comprising: a driver voltage adjusting unit that supplies the calculated reference voltage value or a corresponding reference voltage to the data line driving unit. The self-luminous display device according to claim 4,
The self-luminous display device, wherein the reference voltage is a maximum reference voltage and an intermediate reference voltage of a data line driving unit. Autonomous adjustment of white balance in the effective display area in a self-luminous display device equipped with a dummy pixel for each basic emission color and a luminance detection sensor that detects the emission luminance for each basic emission color outside the effective display area A white balance adjusting device,
A dummy pixel data determination unit that gives a gradation value for detecting a light emission characteristic to each dummy pixel for each basic light emission color when automatic white balance adjustment is performed;
A luminance characteristic detection unit for detecting gamma characteristics related to the emission luminance of the dummy pixels for each basic emission color based on the emission luminance detected for each basic emission color;
A gamma setting unit that updates a gamma conversion table corresponding to each basic light emission color so that the detected gamma characteristic satisfies an appropriate white balance. Autonomous adjustment of white balance in the effective display area in a self-luminous display device equipped with a dummy pixel for each basic emission color and a luminance detection sensor that detects the emission luminance for each basic emission color outside the effective display area A white balance adjusting device,
A dummy pixel data determination unit that gives a gradation value for detecting a light emission characteristic to each dummy pixel for each basic light emission color when automatic white balance adjustment is performed;
A luminance characteristic detection unit for detecting gamma characteristics related to the emission luminance of the dummy pixels for each basic emission color based on the emission luminance detected for each basic emission color;
A driver reference voltage calculation unit that calculates a reference voltage value to be applied to the data line driving unit corresponding to each basic emission color so that the detected gamma characteristic satisfies an appropriate white balance;
And a driver voltage adjusting unit that supplies the calculated reference voltage value or the corresponding reference voltage to the data line driving unit. Autonomous white balance in the effective display area on the computer of the self-luminous display device equipped with a dummy pixel for each basic emission color and a luminance detection sensor that detects the emission luminance for each basic emission color outside the effective display area A computer program that executes a process of adjusting
A process for providing a gradation value for detecting a light emission characteristic to each dummy pixel for each basic light emission color when automatic white balance adjustment is performed;
Based on the emission luminance detected for each basic emission color, a process for detecting gamma characteristics related to the emission luminance of the dummy pixels for each basic emission color;
Processing to update the gamma conversion table corresponding to each basic emission color so that the detected gamma characteristic satisfies an appropriate white balance;
A computer program that executes a process of gamma-converting an input video signal with reference to a gamma conversion table. Autonomous white balance in the effective display area on the computer of the self-luminous display device equipped with a dummy pixel for each basic emission color and a luminance detection sensor that detects the emission luminance for each basic emission color outside the effective display area A computer program that executes a process of adjusting
A process for providing a gradation value for detecting a light emission characteristic to each dummy pixel for each basic light emission color when automatic white balance adjustment is performed;
Based on the emission luminance detected for each basic emission color, a process for detecting gamma characteristics related to the emission luminance of the dummy pixels for each basic emission color;
A process of calculating a reference voltage value to be given to the data line driving unit corresponding to each basic light emission color so that the detected gamma characteristic satisfies an appropriate white balance;
A computer program for executing a process of supplying a calculated reference voltage value or a corresponding reference voltage to the data line driving unit.

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