JP2021089355A - Display device - Google Patents

Abstract

To realize a display device, of which the accuracy of luminance correction is improved, and with which it is possible to estimate the temperature of an image display region with higher accuracy than before.SOLUTION: An image display region 21a out of an OLED panel 21 is covered with a heat-equalizing part 22 equipped with a heat diffusion part of 0.23 kW/m°C or greater in thermal conductivity, and the temperature of the heat-equalizing part 22 is measured by a temperature acquisition part 3. A display control part 4 estimates, on the basis of the temperature information acquired by the temperature acquisition part 3, the degradation amount of each pixel due to the temperature of the image display region 21a and the OLED, and executes luminance correction. As the heat-equalizing part 22 is approximately at the same temperature as the image display region 21a, it is possible to estimate the temperature of the image display region 21a with higher accuracy than before, resulting in a display device, of which the accuracy of luminance correction is improved.SELECTED DRAWING: Figure 1

Description

The present invention relates to a display device including an organic light emitting diode (OLED) panel.

Conventionally, in electronic devices such as displays, a method of measuring the temperature of a heat generating member and performing drive correction based on the temperature information is known for the purpose of suppressing deterioration and reducing heat generation. Further, in recent years, electronic devices have been made smaller and thinner, and it may not be possible to directly measure the temperature of a specific member or region such as a heat generating member or a region affected by the heat generating member due to a problem of space or the like. In such an electronic device, as a method of indirectly estimating the temperature information of a target member or region, for example, the method described in Patent Document 1 can be mentioned.

The method described in Patent Document 1 includes a first temperature sensor for measuring a reference temperature of a control substrate and a second temperature sensor for measuring a temperature in the vicinity of a heat generating member mounted on the control substrate. The surface temperature of the electronic device is estimated based on the temperature information acquired by the second temperature sensor. This makes it possible to estimate the temperature of a part where direct temperature measurement by a temperature sensor is difficult due to space problems.

JP-A-2018-81467

By the way, in recent years, a display device in which each pixel is composed of an OLED is known. This type of display device is regarded as promising in the field of display devices because the display quality can be improved by using the OLED of the self-luminous element.

The OLED exhibits a characteristic that the luminous efficiency is lowered due to the influence of the cumulative light emitting time, the amount of driving current, the environmental temperature, etc., and the light emitting brightness is gradually lowered even if the driving conditions are the same. Further, since the display device using the OLED displays various images, the drive history of each pixel varies. Further, if the temperature distribution varies on the surface on which the image is displayed, the temperature history of each pixel also varies. When the degree of decrease in the brightness of the OLEDs constituting each pixel varies due to these effects, the pixel group having a large degree of decrease in brightness has a higher degree of decrease in brightness than the other pixel groups even under the same driving conditions. However, the brightness becomes low and it appears to be burnt, which causes so-called "burning".

In order to suppress seizure in a display device using an OLED, the degree of brightness reduction of each pixel, that is, the degree of deterioration is estimated, and then the difference in brightness of each pixel is suppressed to a predetermined value or less based on the estimated degree of deterioration. Luminance correction that controls the amount of current in each pixel is effective. In order to improve the accuracy of this brightness correction, it is necessary to improve the accuracy of temperature measurement of each pixel. However, it is difficult to spread the temperature sensors over the entire area of the image display area, and it is not possible to directly measure the temperature of the image display area of the OLED panel composed of each pixel.

Therefore, it is conceivable to indirectly acquire the temperature of the image display region as in the method described in Patent Document 1. In this case, for example, the temperature sensor is arranged on the control board used for the drive control of the OLED panel, and the temperature of the image display area is estimated based on the information of the environmental temperature in which the OLED panel is placed.

However, when the OLED panel is placed in a situation where the temperature of the image display area changes locally or in an environment, it is difficult to accurately estimate the temperature of the image display area by the temperature sensor on the control board. .. In the above situation or environment, for example, only a part of the pixel group emits light, the heat of another heat generating member is locally transferred to the OLED panel, and only a part of the OLED panel is illuminated by sunlight. And so on. In such a situation or environment, the estimated deterioration degree of the OLED and the actual deterioration degree deviate from each other, and the accuracy of the correction is lowered.

In view of the above points, the present invention provides a display device capable of estimating the temperature of the image display area with higher accuracy than before and improving the accuracy of luminance correction regardless of the situation or environment in which the OLED panel is placed. The purpose is to do.

In order to achieve the above object, the display device according to claim 1 is arranged so as to be superimposed on the OLED panel (21) and at least the image display area (21a) of the OLED panel, and diffuses the heat of the OLED panel. The temperature of the image display area is estimated from the heat unit (22), the temperature acquisition unit (3) attached to the heat equalization unit and outputting a signal corresponding to the temperature of the heat equalization unit, and the output signal from the temperature acquisition unit. After that, a display control unit (4) that estimates the amount of deterioration of each pixel constituting the OLED panel and corrects the driving conditions is provided, and the heat equalizing unit has a protruding portion (221) that protrudes from the image display area. In addition to having, it has a heat diffusion part made of a material having a heat conductivity of 0.23 kW / m ° C. or more, the plane size of the heat equalizing part is larger than the plane size of the image display area, and the temperature acquisition part has. It is attached to the protrusion.

As a result, the heat in the image display area of the OLED panel is diffused and equalized by the heat diffusion part of the heat equalizing part, so that the temperature variation in the image display area is suppressed regardless of the environment in which the OLED panel is placed. .. Since the temperature of this image display area can be accurately estimated based on the temperature information of the temperature acquisition parts arranged in the protruding parts protruding from the image display area of the heat equalizing part, it is necessary to arrange a large number of temperature sensors. Is gone. Therefore, regardless of the situation or environment in which the OLED panel is placed, the temperature of the image display area can be estimated with higher accuracy than before, and the display device has improved brightness correction accuracy.

The reference reference numerals in parentheses attached to each component or the like indicate an example of the correspondence between the component or the like and the specific component or the like described in the embodiment described later.

It is a figure which shows the display device of 1st Embodiment. It is a block diagram which shows the structure of the display device of FIG. It is a figure which shows an example of the deterioration curve of OLED. It is a figure which shows the state of the temperature measurement in the conventional display device. It is a figure which shows an example of the situation where a local heat is generated in an OLED panel. It is a figure which shows an example of the environment where the heat from the outside is locally applied to the OLED panel. It is a figure which shows another example of the environment where the heat from the outside is locally applied to the OLED panel. It is a figure which shows the image when the discrepancy between the assumed degree of deterioration of OLED and the actual degree of deterioration occurs. It is a figure which shows the display device of 2nd Embodiment. It is a figure which shows the display device of 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the following embodiments, parts that are the same or equal to each other will be described with the same reference numerals.

(First Embodiment)
The display device 1 of the first embodiment will be described with reference to FIGS. 1 to 3. The display device 1 of the present embodiment is preferably mounted on a vehicle such as an automobile and is preferably applied as an in-vehicle display device capable of displaying various images corresponding to other in-vehicle devices, but of course, other in-vehicle display devices. It can also be used for applications.

In FIG. 1, in order to make it easier to see, the outer shell of the image display area 21a, which will be described later, is shown by a thick solid line in the OLED panel 21. Further, in FIG. 1, in order to make it easy to understand the arrangement relationship of the OLED panel 21, the heat equalizing unit 22, and the temperature acquiring unit 3, which will be described later, a cross section is not shown, but hatching is performed on the heat equalizing unit 22 and the temperature acquiring unit 3. A part of the outer shell of the heat equalizing portion 22 is shown by a broken line.

As shown in FIG. 1, for example, the display device 1 includes a display unit 2 having an OLED panel 21 and a heat equalizing unit 22, a temperature acquisition unit 3 for measuring a part of the temperature of the heat equalizing unit 22, and a temperature. A display control unit 4 that controls the drive of the OLED panel 21 based on the temperature information from the acquisition unit 3 is provided. In the display device 1, for example, as shown in FIG. 2, the display control unit 4 to which the output signal from the temperature acquisition unit 3 and the video signal from the outside are input is various in the OLED panel 21 based on these various signals. It is configured to execute image display control and correction control of its driving conditions.

In the case of in-vehicle use, the video signal from the outside is input from other in-vehicle devices such as a navigation device, a car air conditioner, an in-vehicle camera, and a vehicle body ECU (abbreviation of Electronic Control Unit), for example. ..

The display unit 2 includes an OLED panel 21 and a heat equalizing unit 22 attached to the OLED panel 21 via an adhesive or an adhesive material (not shown). The display unit 2 displays various images corresponding to other in-vehicle devices and the like on the OLED panel 21, and the heat of the OLED panel 21 is transmitted and diffused to the heat equalizing unit 22.

The OLED panel 21 is a known OLED display, and is also referred to as an "organic EL (abbreviation of electro-luminescence) display". The OLED display is, for example, a TFT (thin film transistor) and an OLED stacked in this order on an arbitrary substrate. The TFT is an element that includes a gate electrode, a gate insulating layer, a semiconductor layer, a source electrode, and a drain electrode, and can control current on / off by adjusting the voltage of the gate electrode. A plurality of TFTs are formed, for example, and are used for driving control of each pixel composed of an OLED. For example, an OLED is configured such that a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like are sequentially laminated between a pair of electrodes, and emit light by applying a voltage. To. In an OLED display, a main pixel composed of OLEDs, for example, having three sub-pixels having different emission colors of red, green, and blue, is in one direction in a plan view and in an orthogonal direction orthogonal to the one direction. It is repeatedly arranged along.

Since the configurations of OLEDs, TFTs, and OLED displays, their materials, and the like are known, detailed description thereof will be omitted in this specification. Further, the configuration of the OLED is not limited to the above-mentioned example, and any configuration can be adopted.

The heat equalizing portion 22 covers the front surface, which is the surface of the OLED panel 21 on the image display side, or the back surface on the opposite side, via an adhesive or an adhesive material (not shown), and disperses the heat of the OLED panel 21. It is a member whose overall temperature is substantially uniform. The heat equalizing unit 22 includes a heat diffusion unit made of any material having a thermal conductivity of at least 0.23 kW / m ° C. or higher. The heat equalizing portion 22 becomes equal to the surface temperature of the OLED panel 21 in the thermal equilibrium state. The heat equalizing unit 22 receives heat from the OLED panel 21 which is a heat source and diffuses it by the heat diffusion unit, and by equalizing the heat itself, the OLED panel 21 is also heat-equalized, and the temperature of each pixel in the OLED panel 21 varies. Plays a role in reducing.

For the purpose of increasing the thermal conductivity from the OLED panel 21 which is a heat source to the heat equalizing portion 22, the adhesive or the adhesive material may be configured to contain a filler made of any material having high thermal conductivity. In this case, the heat equalizing unit 22 becomes substantially the same as the temperature of the OLED panel 21 earlier, and the accuracy of temperature measurement by the temperature acquisition unit 3 described later becomes higher.

Hereinafter, for the sake of simplification of the description, the state in which the display device 1 is viewed from the normal direction with respect to the surface of the OLED panel 21 is referred to as “front view”. Further, as shown in FIG. 1, the area for displaying an image in the OLED panel 21 when viewed from the front is referred to as an "image display area 21a", and the plane size of the image display area 21a at this time is referred to as an "image display size". It is called. The image display area 21a can also be said to be an area in the OLED panel 21 in which pixels made of OLEDs are arranged.

As shown in FIG. 1, the heat equalizing portion 22 has a plane size that is at least larger than the image display size of the OLED panel 21 when viewed from the front. The heat equalizing portion 22 may be arranged on either the front surface side or the back surface side of the OLED panel 21, but when it is arranged on the front surface side which is the light extraction surface of each pixel made of the OLED, it has a transparent configuration. Will be done.

When the heat equalizing portion 22 is arranged on the surface side of the OLED panel 21, for example, a high thermal conductivity material having a thermal conductivity of 0.23 kW / m ° C. or higher is placed on an arbitrary light-transmitting base material. The heat diffusing portion is formed in a mesh shape having an aperture ratio of a predetermined value or more. Specifically, the heat equalizing portion 22 is formed of, for example, a silver mesh, a copper mesh, carbon nanowires, silver nanowires, or the like on a translucent substrate such as polyethylene terephthalate (PET) or cycloolefin polymer (COP). It may have a configuration in which a heat diffusion portion is arranged. In this case, it is preferable that the heat diffusion portions are uniformly arranged on any light-transmitting base so that the degree of heat diffusion does not become uneven.

On the other hand, when the heat equalizing portion 22 is arranged on the back surface side of the OLED panel 21 opposite to the front surface, all of the heat equalizing portion 22 is made of a highly thermally conductive material (heat diffusion portion) and has translucency. It may not have a configuration. In this case, the heat equalizing unit 22 may have a heat pipe (not shown) built in in order to make the temperature of the entire heat equalizing unit 22 more uniform. As a result, the heat equalizing portion 22 has a structure in which the heat transport efficiency in the in-plane direction is higher.

As shown in FIG. 1, for example, the heat equalizing portion 22 is a protruding portion 221 whose part protrudes from the image display area 21a of the OLED panel 21 when viewed from the front. The protruding portion 221 is a region for attaching the temperature acquisition portion 3, and is formed at an arbitrary position in the heat equalizing portion 22.

It is sufficient that the temperature acquisition unit 3 can be attached to the projecting portion 221, and the shape, dimensions, projecting direction, and the like thereof are appropriately changed. Further, the protruding portion 221 may be formed so as to protrude from the portion of the heat equalizing portion 22 that overlaps the image display region 21a of the OLED panel 21, and does not necessarily protrude from the outer shell of the image display region 21a in front view. You may.

The temperature acquisition unit 3 is a known temperature sensor, and is, for example, a thermistor. The temperature acquisition unit 3 is arranged at the protruding portion 221 of the heat equalizing unit 22, and outputs an electric signal corresponding to the temperature of the heat equalizing unit 22. The temperature acquisition unit 3 is connected to the display control unit 4 via a flexible wiring 5 such as an FPC. The output signal from the temperature acquisition unit 3 is transmitted to the display control unit 4 and used for temperature estimation of the image display surface of the OLED panel 21.

The display control unit 4 is an electronic control unit in which a CPU, ROM, RAM, I / O, etc. are mounted on an arbitrary circuit board (not shown), and is, for example, a control ECU. The display control unit 4 is connected to an external power source and an electronic device (for example, an in-vehicle device) (not shown), and a video signal from the outside is input. As shown in FIG. 1, for example, the display control unit 4 is connected to the OLED panel 21 by a communication harness 6, and outputs an electric signal to the OLED panel 21 based on a video signal input from the outside. The display control unit 4 acquires the temperature information of the OLED panel 21 from the temperature acquisition unit 3 and executes the current control of the OLED panel 21 in consideration of the temperature information. That is, the display control unit 4 displays various images on the OLED panel 21 based on the video signals from other electronic devices, and the deterioration amount of each pixel is based on the temperature information acquired from the temperature acquisition unit 3. Is estimated, and two controls of drive control for correcting the brightness are executed.

As shown in FIG. 2, the display control unit 4 includes a video signal acquisition unit 41, a temperature information acquisition unit 42, a deterioration amount estimation unit 43, a storage unit 44, and a correction unit 45, and performs the above display control and drive control. Execute.

The video signal acquisition unit 41 acquires, for example, a video signal from an external electronic device, and outputs a drive signal corresponding to the video signal to the correction unit 45. Further, the video signal acquired by the video signal acquisition unit 41 is also used, for example, for calculating the drive current amount and the cumulative drive time of each pixel. The drive current amount and cumulative drive time of each pixel, that is, the drive history of each pixel is used for estimating the deterioration amount of each pixel in the deterioration amount estimation unit 43, and is stored in the storage unit 44 as needed.

The temperature information acquisition unit 42 acquires temperature information of the heat equalizing unit 22 to which the temperature acquisition unit 3 is attached based on the output signal from the temperature acquisition unit 3. The temperature information of the heat equalizing unit 22 acquired by the temperature information acquisition unit 42 is stored in the storage unit 44 as a temperature history of each pixel, and is also used for estimating the deterioration amount of each pixel by the deterioration amount estimation unit 43.

The deterioration amount estimation unit 43 calculates the deterioration amount of each pixel by the drive history and temperature history of each pixel and the program for estimating the deterioration amount of the OLED stored in the storage unit 44. The amount of deterioration of each pixel can be calculated, for example, by applying the acquired drive history and temperature history to the data of the deterioration curve shown in FIG. 3, which plots the relationship between the relative brightness and time. The data of the deterioration curve is obtained by, for example, separately manufacturing an OLED element having the same configuration as the pixel and measuring the brightness, and a plurality of data are prepared for each current amount and each temperature. The estimated deterioration amount of each pixel by the deterioration amount estimation unit 43 is used for the correction of the video signal by the correction unit 45, and is stored in the storage unit 44 as needed.

The deterioration amount calculation of each pixel by the OLED in the deterioration amount estimation unit 43 may be performed by another known method for calculating the deterioration amount of the OLED, and is not limited to the above method.

The storage unit 44 is, for example, a storage medium such as a ROM or RAM, and stores various data and programs for estimating the amount of deterioration such as a deterioration curve of pixels made of OLED.

The correction unit 45 corrects the video signal output to the OLED panel 21 based on the estimated deterioration amount of the deterioration amount estimation unit 43. The correction amount in the correction unit 45 is determined so that the difference in relative luminance of each pixel is equal to or less than a predetermined value, for example, the difference in luminance cannot be recognized by human vision.

The above is the basic configuration of the display device 1 of the present embodiment.

Next, in the display device 1 of the present embodiment, the reason why the accuracy of temperature estimation of the image display area 21a is improved by having the heat equalizing unit 22 is different from that of the conventional display device with reference to FIGS. 4 to 8. It will be explained by the comparison of.

As shown in FIG. 4, for example, a conventional display device includes an OLED panel 21 and a control unit 102 on which a temperature sensor 101 is mounted, and the control unit 102 is connected by a communication harness 6. In a conventional display device, the temperature sensor 101 is used to measure the temperature of the environment in which the display unit 100 is placed. Then, the control unit 102 uses the temperature acquired by the temperature sensor 101 as the temperature of the environment in which the OLED panel 21 is placed, and based on the temperature of the environment, the image display area 21a of the OLED panel 21 in the display unit 100. Estimate the temperature.

However, in a conventional display device having such a configuration, when the OLED panel 21 is placed in a situation or environment where local heat is generated or external heat is locally applied, the image display area 21a The accuracy of temperature estimation is reduced.

Specifically, for example, as shown in FIG. 5, when only a part of the pixel groups of the OLED panel 21 emits light, only a part of the pixel groups generates heat, so that the OLED panel 21 is mounted on the control unit 102. The temperature sensor 101 cannot measure the temperature effect due to such local heat generation. Further, for example, as shown in FIG. 6, a part of the OLED panel 21 is arranged adjacent to another heat generating member, or as shown in FIG. 7, for example, only a part of the OLED panel 21 is exposed to sunlight. The same applies to the case where the solar radiation is illuminated.

When the OLED panel 21 is placed in the above situation or environment, some of the pixel groups have a higher temperature than the other pixel groups, and the degree of deterioration due to the temperature influence is larger than that of the other pixel groups.

However, the temperature sensor 101 arranged in the control unit 102 cannot acquire the temperature information of some of the pixel groups and cannot be reflected in the estimation of the amount of deterioration due to the temperature effect in the part of the pixel groups. As a result, the control unit 102 The accuracy of the brightness correction in is reduced. For example, as shown in FIG. 8, the degree of deterioration due to the temperature effect in the part of the pixel group can actually be B, which is more advanced than A, when the estimation based on the temperature information of the temperature sensor 101 is A.

On the other hand, the brightness correction performed by the control unit 102 is performed based on the degree of deterioration of A estimated based on the temperature information obtained by the temperature sensor 101. However, since the actual degree of deterioration is B, the amount of current is insufficient in the luminance correction assuming A, and the relative luminance after the luminance correction is lower than 1. As a result, some of the pixel groups become darker than the other pixel groups, and the suppression of seizure becomes insufficient.

As described above, the temperature estimation method of the image display area 21a based on the temperature of the environment in which the OLED panel 21 is placed does not reflect the temperature change due to local heat in the above situation or environment, and its accuracy. Is reduced, which causes a decrease in the accuracy of brightness correction.

On the other hand, in the display device 1 of the present embodiment, the front surface side or the back surface side of the image display area 21a of the OLED panel 21 is covered with a heat equalizing portion 22 made of a highly thermally conductive material to equalize the heat. The temperature acquisition unit 3 measures the temperature of the heat unit 22. The heat equalizing unit 22 transfers heat from the OLED panel 21 which is a heat source, diffuses the heat at a high thermal conductivity of 0.23 kW / m ° C. or higher, and is abbreviated as the image display area 21a of the OLED panel 21 in a thermal equilibrium state. It will be the same temperature.

Further, the temperature of the OLED panel 21 itself is also homogenized by the heat equalizing unit 22, and the temperature variation in the image display area 21a is reduced. Therefore, even if the OLED panel 21 is placed in the situation or environment as shown in FIGS. 5 to 7, it is possible to prevent the OLED panel 21 from becoming locally hot due to the action of the heat equalizing unit 22. Further, the temperature may be measured at one place of the heat equalizing unit 22, and the temperature of the image display area 21a can be estimated more accurately without arranging the temperature sensor in the entire area of the image display area 21a. As a result, the accuracy of estimating the amount of deterioration due to the influence of the temperature of each pixel is improved, the deviation between the actual amount of deterioration and the estimated amount of deterioration is suppressed, and the accuracy of the luminance correction is improved as compared with the conventional case.

According to the present embodiment, by providing the heat equalizing unit 22 and the temperature acquisition unit 3 for measuring the temperature thereof, the temperature of the image display area 21a can be changed from the conventional value regardless of the situation or environment in which the OLED panel 21 is placed. The display device 1 can be estimated with high accuracy, and the accuracy of brightness correction is improved.

(Second Embodiment)
The display device 1 of the second embodiment will be described with reference to FIG.

In FIG. 9, in order to make the configuration of the heat equalizing portion 22 easy to understand, the cross section is not shown, but the first heat equalizing portion 22A, the second heat equalizing portion 22B, and the temperature acquiring portion 3 which will be described later are hatched to form a first. A part of the outer shell of the first heat equalizing portion 22A and the second heat equalizing portion 22B is shown by a broken line. Further, in FIG. 9, for convenience of explanation, the left-right direction of the paper surface is defined as the “horizontal direction”, the direction orthogonal to the horizontal direction on the paper surface is defined as the “vertical direction”, and these directions are indicated by arrows.

The display device 1 of the present embodiment is different from the first embodiment in that the heat equalizing portion 22 includes the first heat equalizing portion 22A and the second heat equalizing portion 22B, as shown in FIG. 9, for example. In this embodiment, this difference will be mainly described.

In the present embodiment, the OLED panel 21 has a rectangular shape in which the horizontal dimension is larger than the vertical dimension when viewed from the front.

In the present embodiment, as shown in FIG. 9, for example, the heat equalizing portion 22 has a first heat equalizing portion 22A arranged so as to overlap a part of the image display area 21a in a front view, and the image display area 21a. It has a second heat equalizing portion 22B arranged so as to be superimposed on the remaining portion of the above. That is, the heat equalizing portion 22 has a configuration in which a part and the remaining portion when the image display area 21a is divided into two are covered with two members, the first heat equalizing portion 22A and the second heat equalizing portion 22B. In the present embodiment, the plane size of the heat equalizing portion 22 is the total of the plane sizes of the first heat equalizing portion 22A and the second heat equalizing portion 22B.

For example, the first heat equalizing unit 22A covers the right half of the image display area 21a in front view, receives heat from the right half of the image display area 21a and diffuses it, and equalizes itself and the right half area. It plays a role of heating. The first heat equalizing portion 22A includes a first protruding portion 221A that protrudes from the image display area 21a. A temperature acquisition unit 3 is attached to the first protrusion 221A, and a signal from the temperature acquisition unit 3 is transmitted to the display control unit 4 via the flexible wiring 5, and the temperature of the right half of the image display area 21a is reached. Used for estimation and brightness correction.

For example, the second heat equalizing unit 22B covers the left half of the image display area 21a and plays a role of heat diffusion and heat equalization of the left half of the image display area 21a in a front view. Similar to the first heat equalizing portion 22A, the second heat equalizing portion 22B includes a second protruding portion 221B protruding from the image display area 21a in a front view, and the temperature acquisition portion 3 is attached to the second protruding portion 221B. Has been done. The output signal from the temperature acquisition unit 3 attached to the second protrusion 221B is transmitted to the display control unit 4 via the flexible wiring 5 and used for temperature estimation and brightness correction of the left half of the image display area 21a.

The second heat equalizing portion 22B is arranged, for example, separated from the first heat equalizing portion 22A by separating an arbitrary material having a low thermal conductivity, and transfers and receives heat to and from the first heat equalizing portion 22A. It is not configured. Further, the protruding portions 221A and 221B may be attached to the temperature acquisition portion 3, and their shapes, dimensions, protruding directions and the like are arbitrary.

Hereinafter, for convenience of explanation, the temperature acquisition unit 3 attached to the first protrusion 221A will be referred to as a “first temperature acquisition unit 3”, and the temperature acquisition unit 3 attached to the second protrusion 221B will be referred to as a “second temperature acquisition unit 3”. It is referred to as "temperature acquisition unit 3".

In the present embodiment, the display control unit 4 executes temperature estimation and brightness correction of a part of the image display area 21a based on the temperature information acquired from the first temperature acquisition unit 3. Further, the display control unit 4 executes temperature estimation and brightness correction of the remaining portion of the image display area 21a based on the temperature information acquired from the second temperature acquisition unit 3.

That is, the display device 1 of the present embodiment has a configuration in which the image display area 21a is divided into two areas, temperature information of each area is acquired, and brightness correction of each area is individually executed. As a result, even when the area of the OLED panel 21 is increased, the temperature of the image display area 21a can be estimated accurately by acquiring the temperature of the heat equalizing unit 22 divided into a plurality of areas. The accuracy of brightness correction is also improved.

According to this embodiment, even when the area of the OLED panel 21 is increased, the display device 1 can obtain the effect of the first embodiment.

(Modified example of the second embodiment)
A modified example of the display device 1 of the second embodiment will be described with reference to FIG.

Although the cross section of FIG. 10 is not shown as in FIG. 9, the first heat equalizing portion 22A, the second heat equalizing portion 22B, and the temperature acquisition portion 3 are hatched, and the first heat equalizing portion 22A and the first heat equalizing portion 22A and the first 2 A part of the outer shell of the heat equalizing portion 22B is shown by a broken line. Further, in FIG. 10, similarly to FIG. 9, the horizontal direction and the vertical direction are indicated by arrows for convenience of explanation.

In the display device 1 according to the present modification, the first heat equalizing portion 22A and the second heat equalizing portion 22B are, for example, as shown in FIG. 10, a plurality of elongated extending portions extending in the lateral direction when viewed from the front. Are arranged with a gap between them, and these are formed in a comb-teeth shape in which they are connected at the ends in the vertical direction. In this modification, the heat equalizing portions 22 are staggered so as to fill the gap between the comb teeth (extended portion) of the second heat equalizing portion 22B with the comb teeth portion (extended portion) of the first heat equalizing portion 22A. It is arranged in the shape of a rectangle as a whole. The first heat equalizing portion 22A is configured such that the comb tooth portion is in contact with the comb tooth portion of the second heat equalizing portion 22B when viewed from the front, and heat is exchanged with the second heat equalizing portion 22B. There is.

That is, the heat equalizing portion 22 is arranged so that the gap between one comb tooth member is filled with the other comb tooth member, and the two regions are equalized while the two regions constituting the image display region 21a are equalized. It is configured to equalize heat between each other. As a result, even when the area of the OLED panel 21 is increased, the temperature equalizing portion 22 suppresses the temperature variation in the image display area 21a.

In this modification, the display control unit 4 is from each of the first temperature acquisition unit 3 attached to the first heat equalizing unit 22A and the second temperature acquisition unit 3 attached to the second heat equalizing unit 22B. The temperature information is acquired, and the temperature of the image display region 21a is estimated based on these average temperatures. As a result, even when the area of the OLED panel 21 is increased, the temperature variation of the heat equalizing portion 22 in the plane of the image display region 21a is further suppressed, and the accuracy of the temperature measurement of the heat equalizing portion 22 and thus the image display. The accuracy of temperature estimation in the region 21a is further improved.

According to this modification as well, even when the area of the OLED panel 21 is increased, the display device 1 can obtain the effect of the first embodiment. Further, the image display area 21a is further heat-equalized as compared with the second embodiment, and the effect that the accuracy of temperature estimation of the image display area 21a by the temperature measurement by the heat equalizing unit 22 is further improved can be obtained.

(Other embodiments)
Although the present invention has been described in accordance with Examples, it is understood that the present invention is not limited to the Examples and structures. The present invention also includes various modifications and modifications within a uniform range. In addition, various combinations and forms, as well as other combinations and forms including only one element thereof, more or less, are also within the scope and ideology of the present invention.

(1) For example, in the second and third embodiments described above, when the OLED panel 21 has a vertically long rectangular shape in a front view, the first heat equalizing portion 22A and the second heat equalizing portion 22B are arranged. And dimensions may be appropriately changed according to the image display area 21a. Further, the first heat equalizing portion 22A and the second heat equalizing portion 22B are not limited to examples having substantially the same plane size, and may have significantly different plane sizes.

(2) In the second and third embodiments described above, depending on the area of the OLED panel 21, the heat equalizing portion 22 is divided into three or more regions, each of which is provided with a protruding portion 221 and each projecting. The temperature acquisition unit 3 may be arranged in the unit 221. Even in this case, it is possible to accurately estimate the temperature of the image display area 21a without laying out the temperature sensor so as to cover the entire area of the image display area 21a, and the accuracy of the brightness correction is improved.

(3) In each of the above embodiments, the protrusion 221 may be covered with a cover made of an arbitrary heat insulating material in order to suppress a decrease in accuracy of temperature measurement due to heat from the outside being applied to the protrusion 221 or sunlight. The protrusion 221 may be housed inside the display 2 so as not to be exposed to the sun.

21 OLED panel 21a Image display area 22 Heat equalizing part 22A 1st heat equalizing part 22B 2nd heat equalizing part 221 Protruding part 221A 1st protruding part 221B 2nd protruding part 3 Temperature acquisition unit 4 Display control unit

Claims (6)

With the OLED panel (21)
A heat equalizing portion (22) that is arranged so as to be superimposed on at least an image display area (21a) of the OLED panel and diffuses heat of the OLED panel, and a heat equalizing portion (22).
A temperature acquisition unit (3) attached to the heat equalizing unit and outputting a signal corresponding to the temperature of the heat equalizing unit, and a temperature acquisition unit (3).
A display control unit (4) that estimates the temperature of the image display region based on the output signal from the temperature acquisition unit, then estimates the deterioration amount of each pixel constituting the OLED panel and corrects the driving conditions. Prepare,
The heat equalizing portion has a protruding portion (221) protruding from the image display region, and also has a heat diffusing portion made of a material having a thermal conductivity of 0.23 kW / m ° C. or higher.
The plane size of the heat equalizing portion is larger than the plane size of the image display area.
The temperature acquisition unit is a display device attached to the protrusion. The first aspect of the present invention, wherein the heat equalizing portion is arranged on the side of the surface of the OLED panel which is a light extraction surface, and the mesh-shaped heat diffusing portion is arranged on a translucent base material. Display device. The display device according to claim 1, wherein the heat equalizing portion is composed of only the heat diffusing portion and is arranged on the back surface side of the OLED panel opposite to the front surface which is the light extraction surface. The heat equalizing portion has a first heat equalizing portion (22A) that covers only a part of the image display region and a second heat equalizing portion (22B) that covers the rest of the image display region. And
The first heat equalizing portion has a first protruding portion (221A) protruding from the image display area, and has a first protruding portion (221A).
The second heat equalizing portion has a second protruding portion (221B) protruding from the image display area.
The display device according to any one of claims 1 to 3, wherein the temperature acquisition unit is attached to each of the first protrusion and the second protrusion. The first heat equalizing portion is arranged so as not to come into contact with the second heat equalizing portion.
Based on the temperature information acquired from the first protruding portion, the display control unit corrects the brightness of the portion of the image display region that overlaps with the first heat equalizing portion, and acquires the brightness from the second protruding portion. The display device according to claim 4, wherein the brightness of the portion of the image display area that is superimposed on the second heat equalizing portion is corrected based on the temperature information. The first heat equalizing portion and the second heat equalizing portion have a comb tooth shape, and are arranged so as to be in contact with each other so that the gap between one comb tooth is filled with the other comb tooth portion.
According to claim 4, the display control unit corrects the brightness of the image display area based on the temperature information obtained by averaging the temperature information acquired from the first protruding portion and the temperature information acquired from the second protruding portion. The display device described.

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