JP2003308046A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep the display quality of an organic EL (electroluminescence) display constant in a portable terminal and the like to be utilized in the outdoor. <P>SOLUTION: In the display device 10, the relation among the luminance of a display surface, luminance data to be inputted and an amount of a current to be made to flow through optical element at that time are preliminarily stored in a relation holding part 21. An amount of current measuring part 32 detects the amount of a current made to flow through the optical element and the luminance data inputted to pixels of the optical element and detects the current luminance of the display surface based these data and the data stored in the relation holding part 21. Then, the display device enhances the display quality by adjusting intensity of light emission in accordance with the detected luminance. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a display device. The present invention particularly relates to a technique for improving the display quality of an active matrix type display device.

[0002]

2. Description of the Related Art Notebook type personal computers and portable terminals are becoming widespread. Currently, liquid crystal displays are mainly used in these display devices, and organic EL (El
ectro Luminescence) display. The active matrix drive system is central to the display method of these displays. A display using this method is called an active matrix type display, in which a large number of pixels are arranged vertically and horizontally to form a matrix, and a switch element is arranged in each pixel. Video data is sequentially written for each scanning line by the switch element.

[0003]

Here, in order to keep the display quality of the organic EL display constant, it is necessary to consider the influence of ambient brightness and the like. In particular, it is expected that the outdoor use such as the display screen of a mobile phone will increase in the future, and the improvement of the visibility in various usage situations can be one of the keys to popularize the organic EL display. On the other hand, even for the purpose of maintaining the display quality, it is desirable to avoid adding a new configuration to the device.
Especially in devices such as mobile terminals, there is a strong demand for downsizing.

The present invention has been made in view of such a situation, and an object thereof is to improve the visibility of a display screen. Another object of the present invention is to improve display quality with a simple configuration. Still another object is to reduce deterioration of the optical element.

[0005]

One embodiment of the present invention is a display device. This device includes a light emitting unit including a plurality of optical elements that form pixels for displaying an image, a brightness control unit that detects the environment of the light emitting unit and adjusts the light emission intensity of each pixel according to the environment. With. At least some of the plurality of optical elements are used by the brightness control unit to detect the environment. "Environment of the light emitting part" here
May be the illuminance of the display surface of the light emitting unit or the temperature around the light emitting unit. The "temperature around the light emitting part" is
The ambient temperature around the light emitting unit may be used, or the temperature of the light emitting unit itself increased by light emission may be used. Since a new structure for detecting the environment of the light emitting unit is not added, the visibility of the display screen can be improved or the deterioration of the optical element can be prevented with a simple structure.

As an "optical element", an organic light emitting diode (Organic Light Emitting Diode).
Abbreviated as "D". ) Can be assumed, but is not limited to this. This optical element is included in each pixel, and a display panel in which a plurality of pixels are arranged vertically and horizontally is included in the light emitting unit. The light emitting unit may include a circuit that drives the display panel.

When an OLED is used as this optical element, when light is incident on the organic layer, carriers are generated by the light, so that the current value flowing when a voltage is applied is increased. By utilizing this characteristic, the illuminance at the time of measurement can be calculated by measuring the amount of current flowing through the OLED and comparing it with the current value under the dark room and under the specific illuminance. Further, when the temperature around the OLED changes, the amount of current flowing through the OLED also changes. The temperature around the OLED can be detected by detecting the difference in the amount of current.

The "light emission intensity" may be set for each of RGB in the case of a device for displaying a color image, and the optical element emits light with a brightness corresponding to the intensity. The adjustment of the light emission intensity may be performed by processing such as gamma correction, gain adjustment, white balance adjustment, and light emission time adjustment.

A relationship holding unit may be further provided for storing the relationship between the environment of the light emitting unit, the value of the brightness data to be input to each pixel, and the amount of current flowing through the optical element at that time.
In that case, the brightness control unit detects the value of the brightness data and the current amount in the pixels of some of the optical elements, and based on the relationship between these values and the environment, the brightness data, and the current amount stored in the relationship holding unit, the light emitting unit. Environment may be detected. In this relationship holding unit, data according to a test measurement result before shipment of this device is preset, but it is configured so that data corrected according to the degree of deterioration of the optical element can be reset after shipment. Good.

When the illuminance on the display surface is detected as the environment of the light emitting unit, the relationship holding unit determines the relationship between the brightness data and the amount of current in a dark room and the relationship between the brightness data and the amount of current under a specific illuminance. May be stored. In that case, the brightness control unit compares the current amount corresponding to the value of the specific brightness data in the pixels of some of the optical elements and the current amount corresponding to the value of the specific brightness data under the dark room and under the specific illuminance. The illuminance of the display surface may be detected according to the difference. "Under the darkroom"
Indicates that the illuminance is zero or is sufficiently dark.

The relationship holding unit in another form stores the relationship between the environment of the light emitting unit, the value of the brightness data when the light emitting unit displays a predetermined reference image, and the amount of current flowing through the optical element at that time. May be. In that case, the brightness control unit
The value of the luminance data and the current amount in the pixels of some optical elements when the light emitting unit actually displays the reference image is detected, and the relationship between the environment, the luminance data, and the current amount stored in the relation holding unit is detected. The environment of the light emitting unit may be detected based on the above.

The relationship holding unit in another form may store the relationship between the environment of the light emitting unit, the value of the brightness data, the amount of current, and the target value for adjusting the emission intensity under the environment. In that case, the brightness control unit detects the value of the brightness data and the amount of current in the pixels of some of the optical elements, and determines the relationship between these values and the environment, the brightness data, the amount of current, and the adjustment target value stored in the relationship holding unit. An actual adjustment target value may be set based on the adjustment target value, and the emission intensity of each pixel may be adjusted based on the adjustment target value. The “adjustment target value” indicates the adjusted value of the brightness data to be input to each pixel.

When the ambient temperature is detected as the environment of the light emitting section, the temperature may be detected when the light emitting section is shielded from light. The image pickup unit further includes an optical element for image pickup,
The brightness control unit detects the amount of current affected by the illuminance component by using a part of the imaging optical element, and detects the illuminance component and the temperature component by using a part of the optical element for displaying an image. The affected current amount may be detected, and the current amount affected only by the temperature component may be detected based on the difference between these two current amounts. It should be noted that any combination or rearrangement of the above components is also effective as an aspect of the present invention.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A display device according to the present embodiment is a mobile communication device such as a mobile phone having an active matrix organic EL display as a display section. This display device detects the illuminance of the display surface as the environment of the display, and adjusts the emission intensity according to the illuminance. An OLED included in the display panel is used to detect the illuminance. That is, this OLED is used for both image display on the display screen and illuminance detection.

FIG. 1 shows the configuration of the display device according to this embodiment. The display device 10 includes a drive unit 20, a light emitting unit 30,
It has a communication unit 40 and an antenna 42. Light emitting unit 30
Has a display panel 34 including a plurality of pixels for displaying an image, and a current amount measuring unit 32 for detecting the amount of current flowing through each OLED. OLED of at least a part of the plurality of OLEDs forming each pixel in the display panel 34
Although the ED is also used for illuminance detection, the OLED will be referred to as “measuring OLED” for convenience hereinafter. The current amount measuring unit 32 detects the amount of current flowing through the measurement OLED and outputs it to the drive unit 20.

The drive unit 20 for setting the intensity of light emission according to the input video signal level has a relationship holding unit 21, a brightness control unit 22, a D / A converter 24, an MPU 25, a memory 26, and a timing signal generation circuit 27. including. The relationship holding unit 21 stores the relationship between the illuminance of the display surface, the value of the brightness data to be input to each pixel, and the amount of current that should flow through the OLED at that time. These relations are measured before shipment before and after the shipment in a dark room and a specific illuminance, and the illuminance y can be calculated if the current amount x is known.
It is stored in the relationship holding unit 21 in the form of (x). By the calculation using this function, the illuminance on the display surface is calculated according to the difference between the amount of current detected from the measurement OLED and the amount of current corresponding to the same luminance data under a dark room and under a specific illuminance.

The brightness control section 22 detects the illuminance on the display surface of the light emitting section 30 by using the measuring OLED and adjusts the luminescence intensity of each pixel according to the illuminance. The brightness control unit 22
The video signal is adjusted based on the result analyzed by the MPU 25. The memory 26 is used as a buffer for the input video signal. The MPU 25 and the memory 26 are connected to the brightness control unit 22 via the bus 28. In addition, MP
U25 and memory 26 are shown in FIG.
Although it is expressed as being connected only to, it may actually be connected to other circuits and used for its processing. However,
The description and description in the drawings are omitted for convenience.

The D / A converter 24 includes a brightness control section 22.
The video signal adjusted by is converted into an analog signal and output to the light emitting unit 30. Timing signal generation circuit 27
Generates a timing signal and outputs it to the D / A converter 24 and the light emitting unit 30. The communication unit 40 includes the antenna 4
The video signal received via 2 is output to the drive unit 20 as a digital signal for each RGB.

FIG. 2 is a functional block diagram showing a detailed structure of the brightness control section. The brightness control unit 22 uses the illuminance detection unit 5
0, an adjustment processing unit 52, a correspondence holding unit 56, and an adjustment value calculation unit 58. The illuminance detection unit 50 detects the value of the brightness data input to the pixel of the measurement OLED and the amount of current flowing in the measurement OLED. The brightness data is acquired from the communication unit 40 or the memory 26, and the current amount is acquired from the current amount measuring unit 32. The illuminance detection unit 50 detects the illuminance of the display surface based on these data and the function y = f (x) stored in the relationship holding unit 21.

The correspondence holding unit 56 stores the relationship between the illuminance of the display surface and the adjustment target value of the emission intensity under the illuminance. These relationships are stored in the form of a function z = g (y) so that the adjustment target value z can be calculated if the illuminance y is known.
The adjustment value calculation unit 58 uses the illuminance y detected by the illuminance detection unit 50 and the function z = g stored in the correspondence holding unit 56.
An adjustment target value z of the emission intensity is calculated based on (y).
The adjustment processing unit 52 adjusts the video signal input from the communication unit 40 or the memory 26 according to the adjustment target value calculated by the adjustment value calculation unit 58, and outputs the adjusted video signal to the D / A converter 24. Adjust.

FIG. 3 illustrates a circuit configuration included in the pixel. This figure shows a circuit configuration for one pixel. Power supply line Vd
d supplies power to each pixel. The selection line SL propagates a selection signal that determines the timing of writing luminance data to each pixel. The data line DL propagates the luminance data input to each pixel.

The pixel Pix has a first transistor Tr.
10, a second transistor Tr20, an OLED, a resistor R, and a voltmeter 60 are included. The first transistor Tr10 is a switch element that turns on / off the luminance data writing to the pixel Pix, and its gate electrode is the selection line SL.
, The drain electrode (or source electrode) is connected to the data line, and the source electrode (or drain electrode) is connected to the gate electrode of the second transistor Tr20. The second transistor Tr20 is a driving element that drives the OLED, and its source electrode is the power supply line Vdd.
And the drain electrode is connected to the anode electrode of the OLED. A resistor R is connected between the cathode electrode of the OLED and the ground potential. The resistance R is, for example, a resistance of 1Ω, and the voltmeter 60 measures the voltage across the resistance. Since the voltage value and the resistance value are known, the current amount is obtained, and this is detected by the current amount measuring unit 32.

FIG. 4 shows the relationship between the illuminance, the brightness data, and the current amount stored in the relationship holding unit. In the figure, the horizontal axis represents the brightness data and the vertical axis represents the current amount. A line 90 shows the relationship between the luminance data and the amount of current in a dark room. Line 9
2 shows the relationship between the luminance data and the amount of current measured in advance under a specific illuminance. The line 94 indicates the illuminance detection unit 5
The relationship between the luminance data actually detected by 0 and the amount of current is shown. Regarding the amount of current corresponding to specific brightness data a,
The illuminance corresponding to the line 94 can be obtained based on the ratio of the current amount difference d1 between the specific illuminance and the dark room and the difference amount d2 between the actually detected current amount and the current amount under the dark room. However, the relationship holding unit 21 does not necessarily need to store the data itself shown in the lines 90 and 92, but stores the characteristics shown in FIG. 4 in the form of a function that obtains the illuminance if the brightness data and the current amount are known. It's enough.

With the above structure, the emission intensity can be adjusted according to the illuminance, and the visibility of the displayed contents can be improved.
Further, since a new configuration such as an illuminometer is not added for measuring the illuminance, the configuration can be simplified, which contributes to downsizing of the device.

(Second Embodiment) In the present embodiment,
The process from obtaining the adjustment target value of the video signal from the detected brightness data and the amount of current is different from that of the first embodiment.
That is, in the first embodiment, the illuminance is obtained from the detected luminance data and the current amount, and then the adjustment target value is obtained from the illuminance. However, in the present embodiment, the adjustment target value is directly obtained from the detected luminance data and the current amount. The difference is that the value is obtained.

Referring to FIG. 1 of the first embodiment,
The relationship holding unit 21 stores the relationship between the illuminance of the display surface, the value of the brightness data to be input to each pixel, the amount of current that should flow through the optical element at that time, and the adjustment target value of the emission intensity under that illuminance. That is, the function y = f (x) stored in the relationship holding unit 21 and the correspondence holding unit 5 in the first embodiment.
Both of the functions z = g (y) stored by 6 are combined functions z = g
It is stored in the relationship holding unit 21 of the present embodiment in the form of (f (x)).

FIG. 5 is a functional block diagram showing a detailed structure of the brightness control section in the second embodiment. The adjustment value calculation unit 58 in FIG. 5 detects the value of the luminance data and the current amount in the pixel of the measurement OLED, and based on these and the combined function z = g (f (x)) stored in the relationship holding unit 21. The actual adjustment target value z is set. The adjustment processing unit 52 is the communication unit 4
0 or the video signal input from the memory 26 is adjusted based on the set adjustment target value and is output to the D / A converter 24, whereby the emission intensity of each pixel is adjusted.

With the above structure, the emission intensity can be adjusted according to the illuminance, and the visibility of the displayed contents can be improved. Further, the process of obtaining the adjustment target value from the detected brightness data and the amount of current can be simplified.

(Third Embodiment) In the present embodiment,
The relationship between the brightness data when a predetermined reference image is displayed and the amount of current flowing at that time is stored in advance,
The first point is that the emission intensity is adjusted based on the relationship between the luminance data and the current amount when the same reference image is actually displayed.
Different from the embodiment. Hereinafter, the description will be focused on the differences from the first embodiment, and the description of the common configurations will be omitted.

Referring to FIG. 1 of the first embodiment,
The relationship holding unit 21 stores the relationship between the illuminance of the display surface, the value of the brightness data when the light emitting unit 30 displays a predetermined reference image, and the amount of current flowing through the OLED at that time.
These relationships are measured and recorded in advance before the display device 10 is shipped. Even if the same reference image is displayed, the illuminance is calculated from the brightness data and the current amount when the reference image is actually displayed, paying attention to the fact that the relationship between the brightness data and the current amount is different if the illuminance is different. It is the purpose.

FIG. 6 is a functional block diagram showing a detailed structure of the brightness control section in the third embodiment. The brightness control unit 22 of FIG. 6 differs from the brightness control unit 22 of FIG. 2 of the first embodiment in that it further includes a reference image holding unit 54. The reference image holding unit 54 stores the reference image. The adjustment processing unit 52 outputs the reference image stored in the reference image holding unit 54 to the D / A converter 24 when the current amount is detected. At this time, the illuminance detection unit 50 detects the value of the luminance data and the current amount in the pixel of the measurement OLED when the light emitting unit 30 actually displays the reference image, and the function y = stored in the relationship holding unit 21 with them. The illuminance on the display surface is detected based on f (x). The adjustment value calculator 58 calculates the illuminance and the function z = g.
The adjustment target value is detected based on (y), and the adjustment processing unit 52 adjusts the video signal according to the detected value. Also with the above configuration, the emission intensity can be adjusted according to the illuminance, and the visibility of the display content can be improved.

(Fourth Embodiment) A display device according to the present embodiment is a television receiver having an active matrix type organic EL display as a display section.
This is realized as a mobile information terminal. This display device
Although the configuration of the drive unit is different from that of the first to third embodiments,
The procedure for detecting the brightness data and the amount of current and the procedure for adjusting the emission intensity according to the detection result are common to the first to third embodiments. The difference will be mainly described below.

FIG. 7 shows the structure of the display device according to the fourth embodiment. The tuner 80 receives the video signal and the sync signal via the antenna 42 and outputs them to the sync separation circuit 70.
Separates. The timing signal generation circuit 27 generates a timing signal based on the synchronization signal. The Y / C separation circuit 72 separates the video signal into a luminance signal and a color signal and
It is converted into a B signal, and this is converted to the brightness control unit 22, the MPU 25,
And adjusted by the memory 26. Adjusted RG
The B signal is divided into a plurality of RGB signals by the multi-phase conversion circuit 74, and these signals are converted into analog signals by the D / A converter 24. The polyphase circuit 74 is
For example, when the display panel 34 is divided into four and the display is processed, the RGB signals may be divided into four. The multi-phase conversion circuit 74 and the D / A converter 24 are the timing signal generation circuit 2
It operates based on the timing signal generated by 7.

The structure of the brightness controller 22 and the method of adjusting the light emission intensity may be the same as in any of the first to third embodiments. With the above configuration, the light emission intensity can be adjusted according to the illuminance, and the visibility of the display content can be improved, as in the first embodiment.

(Fifth Embodiment) The display device according to the fifth embodiment detects the ambient temperature as the environment of the display and adjusts the light emission intensity according to the temperature.
Different from the embodiment. Hereinafter, differences from the first to fourth embodiments will be mainly described. First, the OLED included in the display panel is used to detect the temperature. That is, this OLED
Is used for both image display on the display screen and temperature detection. This display device is also a mobile communication device such as a mobile phone as in the first embodiment.

FIG. 8 shows the configuration of the display device according to this embodiment. The light-shielding detection unit 98 detects whether the display panel 34 of the light emitting unit 30 is in a light-shielded state. The light-shielding detection unit 98 detects whether or not the mobile phone including this display device is folded, and thus the display panel 3 is detected.
It is detected whether or not 4 is shielded from light. This detection method may be a mechanical method, an optical method, or an electrical method for detecting the folded state.

The relationship holding unit 21 includes an ambient temperature, a value of brightness data to be input to each pixel, and an OLED at that time.
The relationship between the amounts of currents that should flow is stored. These relationships are measured at a specific temperature before shipment, and are stored in the relationship holding unit 21 in the form of a function y = f (x) so that the temperature y can be calculated if the current amount x is known. By the calculation using this function, the ambient temperature is calculated according to the difference between the amount of current detected from the measurement OLED and the amount of current corresponding to the same brightness data under the specific temperature. Brightness control unit 22
Detects the ambient temperature of the light emitting section 30 by using the measuring OLED and adjusts the light emission intensity of each pixel according to the temperature. The other configuration and operation of this figure are similar to those of the first embodiment.

FIG. 9 is a functional block diagram showing a detailed structure of the brightness control section. The temperature detection unit 96 includes the light shielding detection unit 9
When 8 detects the light shielding state, the value of the brightness data input to the pixel of the measurement OLED and the amount of current flowing through the measurement OLED are detected. The temperature detecting unit 96 uses the detected data and the function y = f (x) stored in the relationship holding unit 21.
The ambient temperature is detected based on.

The correspondence holding unit 56 stores the relationship between the ambient temperature and the target value for adjusting the emission intensity under that temperature.
These relationships are stored in the form of a function z = g (y) that allows the adjustment target value z to be calculated if the temperature y is known. The adjustment value calculation unit 58 calculates the adjustment target value z of the emission intensity based on the temperature y detected by the temperature detection unit 96 and the function z = g (y) stored in the correspondence holding unit 56. The other configuration and operation of this figure are similar to those of the first embodiment.

The relationship between the temperature, the brightness data, and the amount of current stored in the relationship holding unit 21 is shown in FIG. The relationship between the brightness data and the amount of current under a specific temperature is shown by lines 90 and 92, respectively. The line 94 indicates the temperature detection unit 9
6 shows the relationship between the luminance data actually detected and the amount of current. Point to detect temperature based on these differences,
The point that these relationships are stored in the form of a function is the same as in the first embodiment. However, although the lines are drawn linearly in FIG. 4, the lines may be curved depending on the material characteristics and the like.

With the above structure, the emission intensity can be adjusted according to the temperature. Even when an OLED that deteriorates at high temperatures is adopted, it is possible to suppress heat generation during light emission and reduce deterioration by adjusting the light emission intensity. Moreover, since a new configuration such as a thermometer is not added for temperature measurement, the configuration can be simplified, which contributes to downsizing of the device.

(Sixth Embodiment) The present embodiment is common to the second embodiment in the process of obtaining the adjustment target value of the video signal from the detected luminance data and current amount. However,
The relationship holding unit 21 of the present embodiment combines the function y = f (x) described in the fifth embodiment and the function z = g (y) stored in the correspondence holding unit 56 into a combined function z = g (f (X))
Memorize in the form of. The other configuration and its operation are similar to those of the second embodiment. This can simplify the process of obtaining the adjustment target value from the detected brightness data and the amount of current.

(Seventh Embodiment) In this embodiment, the relationship between the brightness data when a predetermined reference image is displayed and the current amount is stored in advance, and the brightness data when the same reference image is actually displayed is stored. Is common to the third embodiment in that the emission intensity is adjusted based on the relationship between the current amount and the current amount. However, the present embodiment is different in that even when the same reference image is displayed, it is premised that the amount of current is different if the ambient temperature is different.

FIG. 10 is a functional block diagram showing the detailed structure of the brightness control section in the seventh embodiment. The functions of the temperature detection unit 96, the correspondence holding unit 56, and the adjustment value calculation unit 58 are the same as those in the fourth embodiment. Other configurations in this figure are the same as those in the third embodiment. Also with the above configuration, the deterioration of the OLED can be reduced with a simple configuration.

(Eighth Embodiment) This embodiment is a fourth embodiment in that it is a portable information terminal having a function of a television receiver.
It is common to the embodiments. However, as shown in FIG.
The drive unit 20 of this embodiment is different from that of the fourth embodiment in that it further includes a light-shielding detection unit 98. The function of the light shielding detection unit 98 is similar to that of the fifth to seventh embodiments. The functions of the relationship holding unit 21 and the brightness control unit 22 can employ any of the fifth to seventh embodiments.

(Ninth Embodiment) This embodiment differs from the first to eighth embodiments in that it has an image pickup section. In the present embodiment, it is assumed that the current amount measured by the current amount measuring unit 32 is affected by both the illuminance component and the temperature component on the display panel 34. Then, the current amount measured by the current amount measuring unit 32 is compared with the current amount affected by only the illuminance component to obtain the current amount affected by only the temperature component.

FIG. 12 shows the structure of a display device according to the ninth embodiment. The image capturing section 100 includes a CCD 102 and an illuminance measuring section 104. The CCD 102 is composed of a plurality of optical elements such as photodiodes. The illuminance measuring unit 104 measures the illuminance on the imaging surface using the optical element of the CCD 102. The measured illuminance is the brightness control unit 22.
Sent to. The other configuration of this figure is basically the same as that of the fifth embodiment. However, the brightness control unit 22 uses the illuminance measurement unit 1
Current amount measuring unit 3 based on the illuminance measured by 04.
The influence of the illuminance component is excluded from the amount of current measured in 2. As a result, the amount of current affected only by the temperature component can be obtained, and the emission intensity can be adjusted with high accuracy even under the above assumption.

The relationship holding unit 21 stores in advance both the relationship between the illuminance, the brightness data, and the current amount, and the relationship between the temperature, the brightness data, and the current amount. Brightness control unit 22
Is the relationship between the illuminance measured by the illuminance measuring unit 104 and the relationship holding unit 21.
The amount of current that should flow to the pixel of the display panel 34 under the illuminance is calculated based on the data stored by the. When there is a difference between the current amount and the current amount measured by the current amount measuring unit 32, it is considered that the difference is due to the temperature component. The brightness control unit 22 detects the temperature based on the difference between the current amounts and the data stored in the relationship holding unit 21. The emission intensity is adjusted according to the temperature detected here.

The present invention has been described above based on the embodiments. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications can be made to the combination of each constituent element and each processing process, and such modifications are also within the scope of the present invention. . Some modifications will be described below.

In each of the embodiments, the relationship holding unit 21 stores the relationship between the illuminance, the brightness data, and the current amount in the form of a function, but in the modification, these are stored in the form of a table. Also by the above, the display quality can be improved with a simple configuration. Further, although the illuminance and the adjustment target value are detected separately in the third embodiment, the adjustment target value may be directly calculated from the brightness data and the current amount as in the second embodiment. Similarly, although the temperature and the adjustment target value are detected separately in the seventh embodiment, the adjustment target value may be directly calculated as in the sixth embodiment.

[0051]

According to the present invention, it is possible to adjust the display state according to the environment in the display device using the optical element.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a display device according to a first embodiment.

FIG. 2 is a functional block diagram showing a detailed configuration of a brightness control unit in the first embodiment.

FIG. 3 is a diagram illustrating a circuit configuration included in a pixel.

[FIG. 4] Illuminance and luminance data stored in a relationship holding unit,
It is a figure which shows the relationship of a current amount.

FIG. 5 is a functional block diagram showing a detailed configuration of a brightness control unit in the second embodiment.

FIG. 6 is a functional block diagram showing a detailed configuration of a brightness control unit in the third embodiment.

FIG. 7 is a diagram showing a configuration of a display device according to a fourth embodiment.

FIG. 8 is a diagram showing a configuration of a display device according to a fifth embodiment.

FIG. 9 is a functional block diagram showing a detailed configuration of a brightness control unit in the fifth embodiment.

FIG. 10 is a functional block diagram showing a detailed configuration of a brightness control unit in the seventh embodiment.

FIG. 11 is a diagram showing a configuration of a display device according to an eighth embodiment.

FIG. 12 is a diagram showing a configuration of a display device in a ninth embodiment.

[Explanation of symbols]

10 display device, 20 drive unit, 21 relationship holding unit, 22 brightness control unit, 30 light emitting unit, 32 current amount measuring unit, 34 display panel, 96 temperature detecting unit, 98 light shielding detecting unit, 100 image pickup unit.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/14 H05B 33/14 A (72) Inventor Yukio Mori 2-5 Keihanhondori, Moriguchi-shi, Osaka No. 5 In Sanyo Electric Co., Ltd. (72) Inventor Atsuhiro Yamashita 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture No. 5-5 Sanyo Electric Co., Ltd. (72) Inventor Shin Tanase 2-chome, Keihan Hondori, Moriguchi City, Osaka Prefecture 5-5 Sanyo Electric Co., Ltd. (72) Inventor Shigeo Kinoshita 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. F-term (reference) 3K007 AB11 AB17 DB03 GA04 5C080 AA06 BB05 CC03 DD04 DD29 EE29 FF11 GG08 GG12 JJ02 JJ05

Claims (9)

[Claims] 1. A light emitting unit including a plurality of optical elements that constitute a pixel for displaying an image, and a brightness control unit that detects the environment of the light emitting unit and adjusts the light emission intensity of each pixel according to the environment. And at least a part of the optical elements of the plurality of optical elements is used for detecting the environment by the brightness control unit. 2. A relationship holding unit for storing the relationship between the environment of the light emitting unit, the value of the brightness data to be input to each pixel, and the amount of current that should flow through the optical element at that time, the brightness control unit further comprising: Detecting the value of the brightness data and the amount of current in the pixels of the part of the optical elements, and detecting the environment of the light emitting unit based on the relationship between these values and the environment stored in the relationship holding unit, the brightness data, and the amount of current The display device according to claim 1, wherein: 3. A relationship holding unit for storing the relationship between the environment during light emission, the value of the brightness data when the light emitting unit displays a predetermined reference image, and the amount of current flowing through the optical element at that time. However, the brightness control unit detects a value and a current amount of brightness data in pixels of the some optical elements when the light emitting unit actually displays the reference image, and the relationship holding unit stores them. The display device according to claim 1, wherein the environment of the light emitting unit is detected on the basis of the relationship among the environment, the brightness data, and the amount of current. 4. The environment of the light emitting portion, the value of luminance data to be input to each pixel, the amount of current flowing through the optical element at that time,
And a relationship holding unit that stores a relationship between the adjustment target values of the light emission intensity under the environment, and the brightness control unit detects a value of brightness data and a current amount in pixels of the some optical elements. , The actual adjustment target value is set based on the relationship among these and the environment, the brightness data, the current amount, and the adjustment target value stored in the relationship holding unit, and the emission intensity of each pixel is adjusted based on the adjustment target value. The display device according to claim 1, wherein: 5. The environment stored in the relationship holding unit and the environment detected by the brightness control unit are illuminance on the display surface of the light emitting unit. Display device. 6. The relationship holding unit stores a relationship between brightness data and a current amount under a dark room, and a relationship between brightness data and a current amount under a specific illuminance, and the brightness control unit includes: The display surface according to the difference between the amount of current corresponding to the value of specific luminance data in the pixels of some optical elements and the amount of current corresponding to the value of specific luminance data under the dark room and under specific illuminance. The display device according to claim 5, wherein the illuminance is detected. 7. The display device according to claim 1, wherein the environment stored in the relationship holding unit and the environment detected by the brightness control unit are temperatures around the light emitting unit. . 8. A light-shielding detector for detecting whether or not the one part of the optical elements is in a light-shielded state, wherein the brightness controller is configured to detect the light-shielded state when the light-shielded state is detected. The display device according to claim 7, wherein the temperature is detected by using some optical elements. 9. The image pickup unit further includes an image pickup optical element, wherein the brightness control unit is configured to detect the illuminance of the image pickup surface based on a part of the image pickup optical element. The display device according to claim 1, wherein an influence of an illuminance component is excluded from the amount of current detected by using a part of an optical element for displaying an image.