JP5373570B2 - Vehicle display device - Google Patents

Description

  The present invention relates to a display device for a vehicle that displays a display pattern on a self-luminous display at a gradation determined by image information.

  In general, a display device for a vehicle provided in a passenger compartment of a vehicle is provided in an instrument panel in front of the driver's seat so that a driver seated in the driver's seat can visually recognize the display of each instrument device via the steering wheel. Has been placed. This vehicular display device has a plurality of display areas indicating the traveling speed of the vehicle, the number of revolutions of the engine per unit time, the remaining amount of fuel in the fuel tank, the temperature of engine coolant, and the like. . These display areas are arranged efficiently in the same case so that the driver can understand the vehicle state at a glance.

  The vehicle display device includes a self-luminous display such as an organic EL (Electro Luminescence) element, an inorganic EL element, a fluorescent display tube (VFD), a field discharge display (FED), and the like. Some display devices display a display pattern such as a speedometer or a tachometer. In such a self-luminous display, as disclosed in Patent Document 1 and the like, the light emission characteristics of the light emitting element deteriorate with the lapse of the light emission time, and the luminance obtained by the same input current decreases. Therefore, when an icon is always displayed at a certain position on the screen, when a certain pixel has a high emission luminance, a problem of “burn-in” occurs in which the emission characteristics of these pixels are significantly deteriorated compared to other pixels. It is known to do.

  In the matrix drive type display shown in Patent Document 1, input data for each pixel is integrated for each pixel at a fixed period in a state where the display panel is driven, and the integrated value for all the pixels in a non-use state thereafter. Describes a technical idea of generating correction data for aligning the pixels with the same value and causing each pixel to emit light based on the correction data.

JP 2003-228329 A

  However, in the display shown in Patent Document 1, since it is necessary to monitor each pixel based on input data, a circuit or the like for monitoring the input signal to the light emitting element and storing the accumulation is necessary. Measures were necessary. Therefore, when the light emitting element to be used is changed, the correction method, the circuit configuration, and the like must be changed, which is not versatile.

  When a vehicle display device is mounted on a vehicle, for example, a guarantee period of 10 years (3500 hours) is required. However, if the display is displayed with high brightness, the brightness of the display is kept constant over the guarantee period. There is a problem that it is difficult to maintain, and the display screen becomes darker over the years. Therefore, when the luminance of the display is greatly deteriorated, the display or the vehicle display device itself has to be replaced.

  Therefore, in view of the above-described problems, an object of the present invention is to provide a vehicle display device that can continue to display at a constant luminance without complicating the device configuration.

In order to solve the above problems, the vehicle display device according to claim 1, which is made according to the present invention, has a self-luminous display 15 having a display screen 15 a composed of a plurality of pixels, as shown in the basic configuration diagram of FIG. 1, Image information storage means D1 for storing image information for determining the gradation of each of the plurality of pixels corresponding to the display pattern, and the image information at a luminance corresponding to an initial gradation lower than the gradation determined by the image information. Based on the first display control means P1 to be displayed on the display screen 15a, the display time measuring means P2 for measuring the display time of the self-luminous display 15, and the display time measured by the display time measuring means P2. a luminance degradation amount estimation means P3 to infer the luminance degradation of each of the plurality of pixels, according to the luminance degradation amount increases to the luminance degradation amount estimation means P3 is guessed, the from the initial grayscale A second display control means P4 for displaying the image information on the display screen 15a in the corrected correction gradation so as to approach toward the gradation image information stipulated, and having a.

  According to the vehicle display device of the present invention described in claim 1, the self-luminous display 15 displays the image information with the luminance corresponding to the initial gradation lower than the gradation determined by the first display control means P1. Are displayed on the display screen 15a. Based on the display time of the self light emitting display 15 measured by the display time measuring means P2, the luminance deterioration amount of the self light emitting display 15 is estimated by the luminance deterioration amount estimating means P3. Then, the second display control means P4 displays the image information on the display screen 15a with a corrected gradation that has been corrected from the initial gradation toward the gradation set by the image information in accordance with the luminance deterioration amount. That is, first, when the display of the self light emitting display 15 is controlled by the first display control means P1, and the correction according to the luminance deterioration amount is performed, the display of the self light emitting display 15 is controlled by the second display control means P4. To do.

  According to a second aspect of the present invention, as shown in the basic configuration diagram of FIG. 1, in the vehicle display device according to the first aspect, the initial gradation is the image information within a warranty period of the vehicle display device. The gradation level is smaller than the gradation determined by the above.

  According to the vehicle display device of the present invention described in claim 2 above, even if the second display control means P4 corrects the gradation higher than the initial gradation in accordance with the luminance deterioration amount, the image is displayed within the guarantee period. It is possible to prevent the information from exceeding the gradation determined by the information.

  As shown in the basic configuration diagram of FIG. 1, the invention described in claim 3 has a temperature measuring means 18 for measuring the temperature of the self-luminous display in the vehicle display device according to claim 1 or 2. The brightness deterioration amount estimating means P3 corrects the display time from the relationship between the temperature measured by the temperature measuring means 18 and the lifetime of the self-luminous display 15, and based on the corrected display time, It is a means for estimating the luminance deterioration amount of the light emitting display.

  According to the vehicle display device of the present invention described in claim 3, when the temperature of the self-luminous display 15 is measured by the temperature measuring means 18, the measured temperature and the lifetime of the self-luminous display 15 are calculated. From the relationship, the actually measured display time is corrected. The relationship between the temperature and the lifetime of the self-luminous display 15 has been found to be longer when the temperature is used at a low temperature than when the temperature is used at a high temperature. Correct the display time so that Then, the luminance deterioration amount of the self-luminous display 15 based on the corrected display time is estimated by the luminance deterioration amount estimating means P3.

  According to a fourth aspect of the present invention, as shown in the basic configuration diagram of FIG. 1, in the vehicle display device according to any one of the first to third aspects, the image information is a fixed display of a desired display pattern. The first display unit G11 and the second display unit G12 having a lower luminance than the first display unit G11 formed in a region different from the first display unit G11, and the second display control means P4 Transmissive image information transmitted through a portion corresponding to the first display portion G11 and the image information G1 so as to achieve the correction gradation, and semi-transparent composition to display on the self-luminous display 15 It is characterized by.

  According to the vehicle display device of the present invention described in claim 4 above, the transmission image information and the image information G1 having the correction gradation corresponding to the first display portion G11 of the image information G1 are subjected to the second display control. The brightness of the light-emitting display 15 is corrected by being translucently combined by the means P4 and displayed on the image information G1 displayed on the self-light-emitting display 15.

  As described above, according to the vehicle display device of the present invention described in claim 1, the display screen is displayed with the initial gradation lower than the gradation indicated by the image information, and the luminance deterioration amount is based on the display time. Since the image information is displayed on the display screen with a corrected gradation that is corrected to be higher than the initial gradation according to the luminance deterioration amount, the gradation is adjusted according to the luminance deterioration amount of the self-luminous display. Since the luminance can be kept constant by increasing, even if the luminance of the self-luminous display deteriorates due to secular change or the like, it can be displayed with the same luminance from the start of use. Therefore, without complicating the apparatus configuration, deterioration can be delayed by suppressing the gradation at the start of use of the self-luminous display, and the display screen can be continuously displayed with a constant luminance. In addition, since the device configuration is not complicated, the cost of the device can be prevented, which can contribute to the spread of low-priced vehicles and the like.

  According to the vehicle display device of the present invention described in claim 2, in addition to the effect of the invention described in claim 1, the gradation is corrected to be higher than the initial gradation in accordance with the luminance deterioration amount of the self-luminous display. Even so, since it is possible to prevent the gradation determined by the image information from exceeding the gradation determined during the guarantee period, it is possible to reliably continue to display the display screen with a constant luminance within the guarantee period.

  According to the vehicle display device of the present invention described in claim 3, in addition to the effect of the invention of claim 1 or 2, the display time of the self-luminous display is corrected to a display time suitable for the temperature, Since the luminance deterioration amount is estimated based on the corrected display time, it is possible to estimate the luminance deterioration amount of the self-luminous display more accurately, which is suitable for the use environment of the self-luminous display. The correction gradation can be corrected.

  According to the vehicle display device of the present invention described in claim 4, in addition to the effect of the invention of any one of claims 1 to 3, the transparent image information and the image information are semitransparently combined to form a pixel. Thus, the gradation corresponding to the first display unit can be set as the correction gradation by translucent synthesis of the image information. For example, the gradation can be adjusted using a function of a graphic controller or the like. Since the tone can be corrected, the apparatus can be prevented from becoming complicated and the existing functions can be effectively used to reduce the cost.

It is a block diagram which shows the basic composition of the display apparatus for vehicles of this invention. It is a block diagram which shows schematic structure of the display apparatus for vehicles to this invention. It is a figure which shows the example of a display of the image information of this invention. It is a figure which shows the example of a display of 2nd image information. It is a graph which shows the deterioration relationship between the brightness | luminance and display time in a self-light-emitting display. It is a flowchart which shows an example of the luminance adjustment process which concerns on this invention which CPU of FIG. 2 performs. It is a graph which shows the relationship between the brightness | luminance and display time of the 1st display area in a display screen.

  Hereinafter, an embodiment of a display device for a vehicle according to the present invention will be described below with reference to the drawings of FIGS.

  In FIG. 2, the vehicle display device 1 is incorporated in a vehicle as a graphic meter or the like, for example. The vehicular display device 1 includes a central processing unit (CPU) 11 that performs various processes and controls according to a predetermined program, a ROM 12 that is a read-only memory storing a program for the CPU 11, and the like. A RAM 13 that is a readable / writable memory that stores data and has an area necessary for processing operations of the CPU 11, a graphics controller (GC) 14, a self-luminous display (also referred to as a display) 15, A VRAM (Video Random Access Memory) 16, an EEPROM (electrically erasable programmable read-only memory) 17, and a temperature sensor 18 are included.

  In the CPU 11, a ROM 12, a RAM 13, a GC 14, and a temperature sensor 18 are electrically connected to each other. The CPU 11 is communicably connected to a vehicle-mounted LAN of the vehicle on which the vehicle display device 10 is mounted via a communication device (not shown). The display 14 and the VRAM 16 are connected to the GC 14 via a bus 18 so that various data can be input and output.

  The ROM 12 stores a program for controlling the entire processing in the vehicle display device 1, and the CPU 11 executes the program to output a display request for a desired display image to the GC 14. 15 displays are controlled. That is, the ROM 12 stores various programs for causing the CPU 11 to function as various means such as the display time measuring means P2 and the luminance deterioration amount estimating means P3 in the claims shown in FIG.

  Upon receiving a display request from the CPU 11, the GC 14 causes the display 15 to draw the first image information G1 shown in FIG. 3 and the second image information G2 shown in FIG. 4 based on various information (data) in the VRAM 16. Thus, the first image information G1 and the second image information G2 are switched and displayed on the display 15. In this embodiment, the case where the GC 14 is caused to function as the first display control means P1 and the second display control means P4 in the claims shown in FIG. 1 will be described. However, the CPU 11 is connected to the first display control means P1 and the second display control means P1. Various embodiments can be made such as functioning as at least one of the display control means P4.

  The display 15 has a display screen 15a on which various image information shown in FIGS. 3 and 4 are displayed, and the display screen 15a is provided on the instrument panel of the vehicle so as to be visible from the driver. The display device 15 functions as a known meter by displaying the first image information G1 shown in FIG. 3 on the display screen 15a at the normal time. The display unit 15 is configured to be capable of dot matrix display that can turn on / off display units (pixels) arranged in a vertical and horizontal matrix and draw characters and figures on the display screen 15a. A display device such as an EL (Electro Luminescence) element is arbitrarily used. The display 15 is configured to turn on / off each pixel under the control of the GC 14 to switch the first image information G1, the second image information G2, and the like to the display screen 15a.

  As is well known, the VRAM 16 shown in FIG. 2 is a memory that retains and stores the contents displayed on the display unit 15, and includes the first image information G1 and the second image information G2 described above, and the transmission image. Various information such as information is stored. Therefore, in this embodiment, the VRAM 16 functions as the image information storage means D1 in the claims shown in FIG.

  The first image information G1 is image information that determines the gradation of each of a plurality of pixels constituting the display unit 15 corresponding to a desired display pattern. As shown in FIG. 3, the first image information G1 includes a first display part G11 for fixedly displaying the display pattern, and the first display part G11 formed in a region different from the first display part G11. It has a low-luminance second display unit G12 and an instruction unit G13 that is displayed so as to be rotated to an index indication position corresponding to the measurement amount. In this embodiment, the case where a desired display pattern is a design pattern of a speedometer will be described. However, the present invention is not limited to this, and the display form of the embodiment such as a tachometer, a fuel gauge, etc. It is determined arbitrarily.

  The first display unit G11 is a region where a plurality of scales and indices such as numbers, units, etc. are fixed and displayed at a desired luminance. The second display unit G12 is a background of the display pattern, and is a dark color system having a luminance lower than that of the index such as black, dark gray, and amber. The second display unit G12 can also use a plurality of display colors, for example, a background region corresponding to the danger range of the indicator is used as a warning color. The instruction unit G13 corresponds to a known pointer such as a speedometer, and a predetermined rotation range is updated in accordance with a change in the measurement amount, and the first display unit starts from the center of the first image information G1. It is displayed in a straight line toward G11.

  When the first image information G1 is displayed on the display screen 15a of the display device 15, the portion displaying the first display portion G11 is the first display region 15b, and the portion displaying the second display portion G12 is the second display region 15c. It becomes. The display 15 controls the display of the corresponding pixel elements in the first display area 15b and the second display area 15c. When displaying the first image information G1, the first display area The pixel 15b is displayed with high luminance, and the pixel in the second display area 15c is displayed or turned off with low luminance.

  The second image information G2 is an image that can be switched at a switching request from a user or at a predetermined switching timing from the first display unit G1 that is normally displayed on the display unit 15. That is, the second screen information G2 is displayed in the same area as the first screen information G1 on the display screen 15a of the display 15. As shown in FIG. 4, the second image information G2 is image information indicating a menu screen for selecting “NAVI (navigation)”, “AUDIO”, and “A / C (air conditioner)”.

  The transmissive image information is information that transmits the portion of the first image information G1 corresponding to the second display unit G12 so that the corrected gradation is obtained. The transmission image information indicates an area (display pattern) of the display screen 15a where the luminance is deteriorated due to secular change or the like, and the first display portion G11 of the first image information G1 has a correction gradation corresponding to the luminance deterioration amount. It is a transparent mask image. The transmission image information is information that can specify a part for which the gradation is to be corrected, that is, an image that defines the first display unit G11 corresponding to a display pattern such as a speedometer. ) Used in function.

  As is well known, alpha blending is a function of translucently combining two images using a coefficient (alpha value). The alpha value means the transparency information set for each pixel (point) in the digital image data handled by the computer, and is completely transparent (colorless) to incompletely opaque (not passing the background color at all). ) Can be set. When the computer handles an image, the color information includes information on the three primary colors R (red), G (green), and B (blue) for each pixel, and the color is expressed by a combination thereof (CMYK). 4 colors for mode). When expressing the transparency of a pixel, an alpha value is added to it, and one pixel is displayed by combining four pieces of information.

  Therefore, in this embodiment, it is set as the structure which can specify the 1st display area 15b of the display screen 15a corresponding to the 1st display part G11 with transparent image information, an alpha value is calculated based on luminance degradation amount, A case where the transparency for each pixel in the first display area 15b is defined based on the alpha value will be described. When the alpha value is input from the CPU 11, the GC 14 creates or extracts transparent image information in which the portion corresponding to the first display unit G 11 has the alpha value and stores it in the VRAM 16. One image information G1 is alpha blended and displayed on the display 15. Accordingly, the display 15 displays the gradation of the first display unit G11 with the corrected gradation that is corrected according to the luminance deterioration amount of the first display area 15b, so that the first display area 15b of the display screen 15a is displayed. The brightness at is kept constant. Further, when the GC 14 receives a switching request from the CPU 11, the GC 14 alpha-blends the second image information G 2 and the transmission image information in the VRAM 16 and causes the display 15 to display them.

  The VRAM 16 stores various types of information such as alpha information having an alpha value corresponding to the first image information G1, luminance degradation estimation information, and the like. Then, the CPU 11 accesses the VRAM 16 via the GC 14. The EEPROM 17 stores the display time of the display device 10 and the like.

  The temperature sensor 18 has a sensor element provided in the display 15. The sensor element outputs a temperature signal corresponding to the temperature of the installation location to the CPU 11. The CPU 11 is configured to detect the temperature of the display 15 based on the temperature signal from the temperature sensor 18 and use the temperature for the deterioration determination (estimation) of the display 15 or the like. In addition, when not using temperature for determination of brightness | luminance degradation, it can also delete from the structure of the display apparatus 1 for vehicles.

  Next, an example of a method for setting the corrected luminance for the guarantee period of the vehicle display device 1 will be described below with reference to the drawing of FIG. In FIG. 5, the vertical axis represents the luminance, and the horizontal axis represents the display time of the display 15.

  As shown in the graph L1, the first display area 15b of the display 15 gradually decreases from the initial luminance Bs to the luminance Bm with respect to a time corresponding to the guarantee period T of the vehicle display device 1 such as 10 years. When the luminance characteristic to be displayed is indicated, correction for reducing the gradation of the first display portion G11 of the first image information G1 by the luminance deterioration amount Bd is performed. Therefore, the luminance obtained by subtracting the luminance deterioration amount Bd from the initial luminance Bs is set as the corrected luminance at the start of the vehicle display device 1. Then, in the graph L1, luminance degradation estimation information is created based on the luminance degradation amounts Bd1 and Bd2 corresponding to arbitrary display times T1 and T2 retroactive to the correction period T, and stored in the ROM 12 or the like in advance.

  Note that the luminance deterioration estimation information may be variously different embodiments such as a calculation formula for calculating an alpha value corresponding to the luminance deterioration amount from the display time, and a conversion table. In the present embodiment, in order to simplify the description, a case will be described in which the gradation of only the first display portion G11 of the first image information G1 is corrected, but the present invention is not limited to this. For example, various embodiments can be made such as correcting the gradation of the second display unit G12 described above.

  Next, the CPU 11 described above executes a display time measurement processing program stored in advance in the ROM 12 and functions as the display time measurement means P2 in the claims shown in FIG. The display time information indicating the display time, the counter value, and the like is periodically stored in the EEPROM 17.

  Next, an example of the brightness adjustment processing according to the present invention executed by the CPU 11 of the vehicle display device 1 described above will be described below with reference to the flowchart shown in FIG. Note that this brightness adjustment processing is premised on being called from the upper module when the system of the vehicle display device 1 is activated, for example.

  When the system of the vehicle display device 1 is activated and the luminance adjustment processing program is executed by the CPU 11, the display time is acquired from the EEPROM 17 and stored in the RAM 13 in step S11 shown in FIG. 6, and then the process proceeds to step S12.

  In step S12, a cumulative deterioration amount corresponding to each of the cumulative deterioration amounts of a plurality of pixels is estimated for each display region from the display time of the RAM 13 and the luminance deterioration estimation information, and an alpha value is calculated from the cumulative deterioration amount. Is stored as alpha value information in the VRAM 16, and then the process proceeds to step S13. By this processing, based on the display time and the accumulated deterioration amount, the second display unit G12 and the third display unit G13 in which the first display unit G11, the second display unit G12, and the third display unit G13 have the same brightness. The second alpha value and the third alpha value are specified (calculated) and stored in the VRAM 16. In the present embodiment, since the luminance deterioration estimation information is prepared in advance so that the alpha value can be specified from the display time, the processing is simplified by using the information.

  In step S13, alpha value information indicating the second alpha value, the third alpha value, and the like is output to the GC 14, whereby the alpha value information is stored in the VRAM 16, and control based on the alpha value information of the GC 14 is performed. As a result, the display 15 is displayed, and then the process proceeds to step S14. Accordingly, the GC 14 creates or extracts transmission image information in which the portion corresponding to the first display unit G11 has an alpha value based on the input alpha value, and stores it in the VRAM 16, and stores the transmission image information and the VRAM 16 in the VRAM 16. One image information G1 is alpha blended and displayed on the display 15. In addition, since the luminance degradation of the display unit 15 proceeds slowly, the alpha value information may be output to the GC 14 once at the time of starting the system, but the alpha value information may be output to the GC 14 at an arbitrary timing. Can do.

  In step S14, it is determined whether a system down request has been received. If it is determined that the system down request has not been received (N in S14), it is determined in step S15 whether or not a predetermined time has elapsed. The predetermined time is a predetermined sampling time. In the present embodiment, the predetermined time is determined using a clock function, a timer function, or the like that the CPU 11 has. If it is determined that the predetermined time has not elapsed (N in S15), the process returns to step S14, and a series of processes is repeated. On the other hand, if it is determined that the predetermined time has elapsed (Y in S15), the process proceeds to step S16.

  In step S16, it is determined whether or not the first image information G1 is being displayed based on whether or not the first image information G1 is being displayed on the display 15. When it is determined that the first image information G1 is not being displayed (N in S16), the process returns to step S14, and a series of processes is repeated. On the other hand, if it is determined that the first image information G1 is being displayed (Y in S16), the display time in the RAM 13 is counted up by a predetermined time in step S17, and then the process returns to step S14.

  On the other hand, if it is determined in step S14 that a system down request has been received (Y in S14), the display time of the RAM 13 is stored and saved (stored) in the EEPROM 17 in step S18, and then the process ends. By storing the display time in the EEPROM 17 in this way, it is not necessary to store the deterioration amount for each display unit, so that the processing can be simplified and the capacity of the storage area can be reduced.

  As is apparent from the above description, in the present best mode, the CPU 11 executes the above-described brightness adjustment processing program, whereby the display time measuring means P2 and the brightness deterioration amount estimating means P3 in the claims shown in FIG. Will function as.

  Next, an example of the operation (action) of the vehicular display device 1 according to the present invention will be described below with reference to the drawings of FIGS.

  When the system is activated in response to turning on of an ignition switch of the vehicle, the vehicle display device 1 estimates the luminance deterioration amount based on the display time of the EEPROM 17 and the luminance deterioration estimation information, and determines the luminance deterioration amount. The corresponding initial gradation is specified. Then, the transmission image information corresponding to the initial gradation is created in the VRAM 16, and the transmission image information and the first image information G1 are semitransparently synthesized to correspond to the design pattern of the speedometer on the display screen 15a of the display 15. By displaying the first display part G11 to be displayed, the display of the first image information G1 shown in FIG. 3 is started. At that time, the first display area 15b displays the first image information G1 at a gradation (luminance) corrected to be lower than the gradation determined by the first image information G1.

  When the vehicle display device 1 continues to display the first image information G1 as described above, the first display area 15b in the display screen 15a corresponding to the first display unit G11 corresponds to the display time of the display 15. Luminance deteriorates. Therefore, the vehicle display device 1 measures the display time, estimates the luminance deterioration amount corresponding to the display time, and specifies the alpha value corresponding to the luminance deterioration amount. Then, the transparent image information corresponding to the alpha value and the first image information G1 are translucently combined to display the first image information G1 on the display screen 15a. As a result, the luminance of each pixel in the first display area 15b on the display screen 15a is deteriorated according to the display time, but the gradation of the first display portion G11 of the first image information G1 by the luminance deterioration amount. Therefore, the first display area 15b of the display screen 15a has the same luminance as before. As described above, the vehicular display device 1 corrects the gradation of the first display unit G11 according to the display time, so that the display luminance of the first display region 15b is kept uniform at least during the correction period T. be able to.

  Specifically, as shown in FIG. 7, the vehicle display device 1 has an alpha value of 80% when each pixel in the first display area 15 b of the display 15 at the start of use or replacement has a luminance Bs. The first display portion G11 of the first image information G1 is displayed on the display unit 15 with the initial gradation as described above. When the luminance Bs of the display 15 gradually deteriorates according to the display time as in the graph G2, the alpha value is changed from 80% to 100% so that the first display area 15b in the display screen 15a maintains the luminance Bm. When the display time corresponding to the guarantee period T has elapsed, the alpha value is set to 100%. Accordingly, the vehicle display device 1 can display the first display region 15b with the luminance Bm during the period corresponding to the guarantee period T, as shown in the graph L3.

  In addition, when the vehicle display device 1 samples the speed signal at a predetermined sampling interval and measures the speed (measurement amount) of the vehicle, the second display unit G13 is used to indicate a design pattern corresponding to the speed. Displayed on the display unit G12. That is, the tip of the instruction part G13 is moved and displayed on the second display part G12 according to the measurement amount so as to follow the design pattern. Therefore, since the instruction unit G13 moves according to the measurement amount, the deterioration of the pixel elements corresponding to the movement range of the instruction unit G13 in the second display unit G12 of the display unit 15 is delayed.

  Further, the vehicular display device 1 is configured to display the second image information G2 by the driver or the like via the in-vehicle LAN in a state in which the luminance varies in the first display area 15b and the second display area 15c of the display screen 15a. When the display is requested, the second image information G2 in the VRAM 16 and the transmission image information corresponding to the latest alpha value described above are alpha blended and displayed on the display unit 15. Thereby, since the display 15 adjusts the brightness of the entire screen corresponding to the first display unit G11 and the second display unit G12, the second image information G2 displayed on the display screen 15a is due to burn-in. The brightness variation is not noticeable.

  According to the vehicle display device 1 described above, the display screen 15a is displayed with an initial gradation lower than the gradation indicated by the first image information G1, and the luminance deterioration amount is estimated based on the display time. Since the first image information G1 is displayed on the display screen 15a with a corrected gradation that is corrected to be higher than the initial gradation according to the amount of deterioration, the gradation is increased according to the amount of luminance deterioration of the self-luminous display 15 Since the luminance can be kept constant, even if the luminance of the self-luminous display 15 is deteriorated due to aging or the like, it is possible to display with the same luminance from the start of use. Therefore, without complicating the device configuration, at the start of use of the self-luminous display 15, the deterioration can be delayed by suppressing the gradation, and the display screen 15a can be continuously displayed with a constant luminance. . In addition, since the device configuration is not complicated, the cost of the device can be prevented, which can contribute to the spread of low-priced vehicles and the like.

  Further, according to the vehicle display device 1, even if the gradation is corrected to be higher than the initial gradation according to the luminance deterioration amount of the self-luminous display 15, the floor determined by the first image information G1 is within the guarantee period T. Since it is possible to prevent exceeding the key, the display screen 15a can be reliably displayed with a constant luminance within the guarantee period T.

  Furthermore, according to the vehicular display device 1, since the transmission image information and the first image information G1 are translucently combined to correct the gradation of each pixel, the translucency of the first image information G1 is obtained. The portion corresponding to the first display unit can be set as a correction gradation by combining, and for example, the gradation can be corrected by using a function of a graphic controller or the like. The cost can be reduced by effectively using.

  Further, in the vehicle display device 1 described above, if the luminance deterioration amount is estimated based on the display time of the self-light-emitting display 15 and the temperature at which the light-emitting display 15 is used, a more accurate luminance deterioration amount of the self-light-emitting display can be obtained. Since it can be estimated, the correction gradation can be surely corrected.

  It is known that the display 15 generally has a longer life when used in a low temperature state such as 25 ° C. than in a high temperature state such as 80 ° C. Therefore, the temperature of the display 15 is measured, and life conversion information for estimating the life of the display 15 from the temperature is created in advance. Then, a brightness deterioration amount suitable for the display 15 is estimated from the lifetime obtained based on the measured temperature and the lifetime conversion information.

  For example, when the display apparatus 1 for vehicles mentioned above measures display time, it acquires the temperature which the temperature sensor 18 detected, and calculates | requires the lifetime of the indicator 15 corresponding to temperature from the said lifetime conversion information. And the display apparatus 1 for vehicles correct | amends display time based on the calculated | required lifetime. Specifically, when it can be estimated that the calculated lifetime is shorter than the actual guarantee period T of the display unit 15, correction is performed to increase the display time, and the luminance deterioration amount of the display unit 15 is calculated from the corrected display time. An alpha value corresponding to the luminance deterioration amount is calculated. And the display apparatus 1 for vehicles performs display control of the indicator 15 based on the calculated alpha value.

  Further, for example, temperature adjustment information in which an adjustment coefficient for adjusting the alpha value is tabulated for a plurality of temperature ranges such as 100 to 40 ° C., 40 to 0 ° C., 0 to −40 ° C. is stored in advance in the ROM 12 or the like. When estimating the above-described luminance deterioration amount, the temperature of the display 15 is measured by the temperature sensor 18, and the alpha value corresponding to the display time is adjusted by the adjustment coefficient of the temperature adjustment information to obtain the alpha value. Moreover, it can also be set as embodiment which measures the display time corresponding to every temperature range.

  In this way, if the display time of the display unit 15 is corrected to a display time suitable for the temperature and the amount of luminance deterioration is estimated based on the corrected display time, the luminance deterioration of the display unit 15 can be made more accurate. Since the amount can be estimated, it is possible to correct to a correction gradation suitable for the use environment of the display 15 or the like.

  As described above, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

1 vehicle display device 11 CPU
14 Graphic controller (GC)
15 Self-luminous display (display)
15a display screen 15b first display area 15c second display area 16 VRAM
G1 1st image information G11 1st display part G12 2nd display part G2 2nd image information P1 1st display control means (GC)
P2 Display time measuring means (CPU)
P3 Adjustment brightness specifying means (CPU)
P4 Second display control means (GC)

Claims (4)

A self-luminous display having a display screen composed of a plurality of pixels;
Image information storage means for storing image information for determining the gradation of each of the plurality of pixels corresponding to a display pattern;
First display control means for displaying the image information on the display screen at a luminance corresponding to an initial gradation lower than the gradation defined by the image information;
Display time measuring means for measuring the display time of the self-luminous display;
A luminance deterioration amount estimating means for estimating a luminance deterioration amount of each of the plurality of pixels based on the display time measured by the display time measuring means;
The following luminance degradation amount luminance degradation amount estimation means is speculated increases, the image information is corrected gradation corrected so as to approach toward the gray level stipulated by the image information from the initial gray level on the display screen Second display control means for displaying;
A vehicle display device characterized by comprising:   The vehicle display device according to claim 1, wherein the initial gradation is a gradation level smaller than a gradation determined by the image information within a guarantee period of the vehicle display device. Having temperature measuring means for measuring the temperature of the self-luminous display,
The luminance degradation amount estimating means corrects the display time from the relationship between the temperature measured by the temperature measuring means and the lifetime of the self-luminous display, and based on the corrected display time, the self-luminous display The vehicle display device according to claim 1, wherein the vehicle display device is means for estimating a luminance deterioration amount. The image information includes a first display unit that fixedly displays a desired display pattern, and a second display unit that has a lower luminance than the first display unit formed in a region different from the first display unit,
The second display control means causes the self-luminous display to display by translucently combining the transmission image information transmitted through the portion corresponding to the first display unit and the image information so as to achieve the correction gradation. The vehicle display device according to claim 1, wherein the vehicle display device is a means.

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