JP5279096B2 - Display intensity estimation method and computer program - Google Patents

Description

  The present invention relates to a display intensity estimation method, a display apparatus, and a computer program that estimate display intensity such as luminance or chromaticity of a display surface of a display apparatus for calibration or display characteristic check.

  The display intensity such as the luminance or chromaticity of the display device changes with age. In printing and medical settings where high display quality is required, a sensor that measures the display intensity on the user side after shipment is used to check whether the display intensity maintains the ideal value, and the ideal value is not maintained. In this case, a so-called calibration operation is performed in which the display device is calibrated so that the display intensity becomes an ideal value. As the display device, not only a liquid crystal display device currently generally used, but also a PDP (Plasma Display Panel) display device, an OLED (Organic light-Emitting Diode) display device, a CRT (Cathode Ray Tube) display device, etc. Those with different driving methods are also included.

  In Patent Document 1, image quality data is measured by a photometry unit provided opposite to the liquid crystal display unit, and predetermined ideal registered image quality data is stored. A self-adjusting display system has been proposed in which the difference data is extracted and the liquid crystal display unit is controlled so that the difference data becomes a predetermined value or less. Since this self-adjusting display system can perform photometry without human intervention, there is an advantage that calibration can be performed by remote operation via a network or automatically when necessary.

However, when the photometric unit is configured to be accommodated in the bezel of the liquid crystal display device, the range in which photometry can be performed by the photometric unit is only the periphery of the liquid crystal display surface. Since the display panel is more likely to have uneven brightness or color unevenness at the periphery of the display surface, display is performed with optimal gradation characteristics when calibration is performed based on the photometric results at the periphery of the display surface. There is a fear that you can not. Patent Document 1 proposes a technique for estimating the display intensity at the center of the display surface from the display intensity such as luminance acquired by a sensor at the periphery of the display surface of the display device. Briefly described. FIG. 14 is a schematic diagram for explaining one method for estimating the display intensity of the central portion from the display intensity of the peripheral portion of the display surface of the conventional display panel. In the figure, reference numeral 101 denotes a display device, and an optical sensor 102 capable of automatically measuring the luminance of the peripheral portion of the display surface of the display panel is mounted on the display device 101. In addition, an external light sensor 103 is provided for the user to manually measure the luminance of the central portion of the display surface. When the calculation unit 100 calculates based on the following formula, a so-called correlation operation for creating a relative ratio LUT (Look up Table) as illustrated is performed.

(Relative ratio) = (Measurement value of optical sensor) / (Measurement value of external optical sensor)

The relative ratio LUT illustrated as an example is that in which the display device 101 can perform display with 256 gradations. In order to create the relative ratio LUT, display on the display surface of the display device 101 may be switched and displayed in 256 steps for each gradation, and measurement by the optical sensor 102 and the external light sensor 103 may be performed at each gradation. However, as shown in the figure, only a specific measurement gradation may be measured. When the display device 101 is calibrated, the measurement of only the optical sensor 102 is performed to obtain the measured value of the peripheral portion of the display surface, and the estimated measurement of the central portion of the display surface is performed by referring to the relative ratio LUT. The value can be calculated, and calibration can be performed based on the calculated estimated measurement value at the center.
Japanese Patent No. 4393433

  It is known that a substance constituting a display surface for displaying an image (in the case of a liquid crystal display device, a liquid crystal material, a fluorescent tube used in a backlight, etc.) has a characteristic change due to temperature. FIG. 15 is a temperature characteristic diagram showing a change in luminous efficiency due to a characteristic change depending on the temperature of the liquid crystal material. The X axis indicates the ambient temperature of the display surface, and the Y axis indicates the light emission efficiency of the display surface, that is, the amount of light transmitted to the display surface when the backlight light amount is the same and the drive voltage to the liquid crystal material is the same. According to FIG. 14, the light emission efficiency peaks at around 35 ° C., the light emission efficiency deteriorates as the temperature decreases from 35 ° C., and the light emission efficiency deteriorates as the temperature rises from 35 ° C. Yes.

  The temperature of the display surface varies depending on the content of the display image and the display time. Further, the temperature distribution on the display surface is not uniform, varies depending on the arrangement of the circuit board and the shape of the casing, and the distribution changes with time. Variation in temperature distribution causes variation in luminance values on the display surface, so-called luminance unevenness. Further, if the display device is moved to another environment after the relative ratio LUT is created, or if the season changes, the room temperature naturally changes, and brightness unevenness different from that at the time of creating the relative ratio LUT may occur during calibration. There is also. As described above, by acquiring and storing the relative ratio LUT in advance, it is possible to accurately estimate the estimated measured value at the center of the display surface from the measured value of the optical sensor 102. When the temperature of the display surface and its distribution fluctuate between the time of creation and the time of estimating the measured value at the center, the optimal relative ratio will be different, so the measured value at the center of the display surface should be estimated accurately. There is a problem that can not be.

  The present invention has been made in view of such circumstances, and the object of the present invention is to measure the display intensity for a plurality of display areas in advance and relate the display intensities of the measured display areas to each other. Is stored, the temperature of the display surface at the time of storing the display intensity is also stored, the display intensity of the display surface is measured, and the response is based on the stored display intensity related value. Estimate the display intensity of the other display area, further measure the temperature of the display surface at the time of estimating the display intensity of the other display area, from the comparison with the temperature of the display surface stored in advance and the measured display surface temperature It is an object of the present invention to provide a display intensity estimation method and a computer program for correcting the estimated display intensity of another display area.

According to a first aspect of the present invention, there is provided a display intensity estimation method for a display device comprising: a display panel; display intensity measuring means for measuring display intensity of a display surface of the display panel; and temperature measuring means for measuring temperature. In the display intensity estimation method for estimating the display intensity of the display area not facing the display intensity measuring means, the display efficiency of the display area facing the display intensity measuring means, and the display efficiency of the display area not facing the display intensity measuring means, and a display efficiency group display area of the display surface for different temperatures is stored pre Me, the display intensity of the display area that faces the display intensity measuring means, the display region not facing the display intensity measuring means Correlation that stores in advance a related value that correlates with the display intensity of the image and measures the temperature of an arbitrary display area of the display surface when the related value is stored After the step and the correlation step, the temperature measuring means measures the temperature of an arbitrary display area of the display surface, and the display intensity measuring means measures the display intensity of the display area facing the display intensity measuring means. Then, based on the display intensity of the display area facing the measured display intensity measuring means and the previously stored related value, the display intensity of the display area not facing the display intensity measuring means is estimated, and during the correlation step wherein the first display efficiency and a display efficiency corresponding to the temperature of the display region not facing to the temperature and the display intensity measuring means of the display area facing the display intensity measuring means obtained from the temperature of any display area previously stored in advance temperature and table display area determined from the stored display efficiency group, facing the display intensity measuring means obtained from the temperature of any of the display area that the measured Obtains a second display efficiency and a display efficiency corresponding to the temperature of the display region not facing the intensity measuring means from the pre-stored display efficiency group, determine the rate of change from a comparison of these first, second display efficiency, A calibration step for correcting the display intensity of the display area that does not face the estimated display intensity measuring means based on the obtained change rate is provided.

The display intensity estimation method according to the second aspect of the present invention relates to a display device comprising a display panel, display intensity measuring means for measuring the display intensity of the display surface of the display panel, and temperature measuring means for measuring temperature. In the display intensity estimation method for estimating the display intensity of the display area that does not face the display intensity measuring means, the display efficiency of the display area that faces the display intensity measuring means, and the display of the display area that does not face the display intensity measuring means and efficiency, and display efficiency group display area of the display surface for different temperatures is stored pre Me, the display intensity of the display area that faces the display intensity measuring means, not facing the display intensity measuring means A related value that associates the display intensity of the display area is stored in advance, and the temperature of an arbitrary display area on the display surface when the related value is stored is measured in advance and stored. A first display efficiency corresponding to the temperature is obtained from the display efficiency group, and a correlation step for storing the first display efficiency, and after the correlation step, an arbitrary display area of the display surface is displayed by the temperature measuring means. Measure the temperature, measure the display intensity of the display area facing the display intensity measuring means with the display intensity measuring means, the display intensity of the display area facing the measured display intensity measuring means, and the previously stored relation Based on the value, the display intensity of the display area not facing the display intensity measuring means is estimated, and the temperature of the display area facing the display intensity measuring means obtained from the temperature of an arbitrary display area stored in advance during the correlation step any of the display area where the display intensity corresponding to the temperature of the display region not facing the measuring means obtains a first display efficiency and a display efficiency and the measured Determined from the display efficiency group the second display efficiency and a display efficiency corresponding to the temperature of the display region not facing to the temperature and the display intensity measuring means of the display area facing the display intensity measuring means to be determined from the temperature and the pre-stored, A calibration step for obtaining a change rate from the comparison between the first and second display efficiencies and correcting the display intensity of the display area that does not face the estimated display intensity measuring means based on the obtained change rate is provided. Features.

  In the display intensity estimation method according to the third aspect of the invention, the temperature of any one of the display areas on the display surface is measured, and the temperature of the other display area is determined from the measured temperature of the display area. It is characterized by estimating.

A computer program according to a fourth invention is a computer connected to a display device comprising a display panel, display intensity measuring means for measuring the display intensity of the display surface of the display panel, and temperature measuring means for measuring temperature. is installed on, the computer program for estimating the display intensity of the display area does not face before Symbol table intensive measurement means to the computer, the computer, the display efficiency of the display area facing the display intensity measuring means, said display and display efficiency of the display area not facing the intensity measuring means, allowed to pre Me stored in the display efficiency group display area of the display surface for different temperatures, the display facing the display intensity measuring means of the display surface A related value that associates the display intensity of the area with the display intensity of the display area that does not face the display intensity measuring means is stored in advance. And a correlation step for preliminarily storing the temperature of an arbitrary display area of the display surface at the time when the related value is stored in advance, and after the correlation step, the temperature measurement means can arbitrarily store the display surface. Measuring the display intensity of the display area facing the display intensity measuring means, and measuring the display intensity of the display area facing the display intensity measuring means. Based on the pre-stored related value, the display intensity of the display area not facing the display intensity measuring means is estimated, and the display intensity measuring means obtained from the temperature of an arbitrary display area stored in advance during the correlation step is faced. before the first display efficiency and a display efficiency corresponding to the temperature of the display region not facing to the temperature and the display intensity measuring means of the display area Let determined from pre-stored display efficiency group, the display efficiency corresponding to the temperature of the display region not facing to the temperature and the display intensity measuring means of the display area facing the display intensity measuring means obtained from the temperature of any of the display area that the measured let determined from the second display efficiency group display efficiency and the prestored consisting these first, let obtains the change rate from the comparison of the second display efficiency, the display intensity above is estimated based on the change ratio obtained A calibration step for correcting the display intensity of the display area that does not face the measuring means is executed.

  In the case of the first invention, the second invention, the fourth invention, and the fifth invention, the temperature characteristics of the display efficiency in the display area of the display surface are stored in advance, and the central portion or the peripheral portion of the display surface of the display device, etc. Display intensities such as luminance or chromaticity of different display areas are measured in advance, and associations such as the measured display intensities or relative ratios between the display intensities are stored in a memory or a hard disk as related values. At the same time, the temperature of an arbitrary display area is also measured, and display characteristics such as display efficiency that follows each measured temperature or temperature are stored in a memory or a hard disk. The above is the correlation step performed before the calibration step described later. In the calibration step that is executed on the assumption that the correlation step has been completed, first, the display intensity in which the related value is stored in advance in the correlation step, for example, the display intensity only in the periphery of the display surface is measured. Based on the related value stored in advance, the display intensity of another display area, for example, the central part of the display surface is estimated. Next, the temperature of an arbitrary display area is measured, and the display efficiency corresponding to the measured temperature is obtained from the temperature characteristics of the display efficiency stored in advance. For each display region, how much the display efficiency has changed over time from the correlation step to the calibration step is determined for each display area, and the display intensity estimated using the change rate is corrected.

  In the case of the third invention, the temperature of one of the display areas, for example, one of the different display areas such as the central part and the peripheral part of the display surface is measured, and the other display area is measured. Estimate from the measured temperature.

  In the first invention, the second invention, the fourth invention, and the fifth invention, the time when the display intensity is measured (correlation step and calibration step) is not estimated using only the display intensity measured as in the prior art. ) Is measured in each area, and the estimated display intensity is corrected based on the measured temperature. Therefore, the display intensity can be estimated without depending on the temperature characteristics of the display surface during calibration. Therefore, even when there is a large temperature difference between the display area for measuring the display intensity and the display area for estimating the display intensity at the time of calibration, the display intensity can be estimated with high accuracy. Furthermore, after the related values are stored in advance, the display intensity can be accurately estimated even when the room temperature fluctuates due to relocation of the display device to another environment or seasonal changes.

  In the third invention, it is not necessary to provide a temperature measuring unit for each display area, the parts cost and the manufacturing cost can be reduced, and the display intensity can be estimated with an inexpensive apparatus.

It is a typical perspective view which shows the external appearance of the display apparatus which concerns on this invention. It is typical sectional drawing which shows the structure of the apparatus for performing the display intensity estimation method which concerns on this invention. It is a circuit block diagram which shows the structure of the apparatus for performing the display intensity estimation method which concerns on this invention. It is a schematic diagram which shows an example of display intensity related data. It is the schematic diagram which showed display efficiency temperature characteristic data. It is the schematic diagram which showed display efficiency temperature characteristic data as a graph. It is a flowchart which shows the procedure of the process which produces or updates display intensity related data. It is a flowchart which shows the procedure of a calibration process. It is a flowchart which shows the procedure of the update process of LUT. It is a schematic diagram which shows an example of the display intensity related data which concerns on the modification of this Embodiment. It is a block diagram which shows the structure of the apparatus for performing the display intensity estimation method which concerns on this invention. It is a schematic diagram which shows an example of temperature related data. It is the schematic diagram which showed display efficiency temperature characteristic data. It is a schematic diagram for demonstrating one method of estimating the display intensity of a center part from the display intensity of the peripheral part of the display surface of a display panel. It is a schematic diagram for demonstrating the temperature characteristic of the display efficiency in a display panel.

1. First Embodiment Hereinafter, a specific description will be given based on the drawings showing an embodiment of the present invention.
1-1. Mechanism FIG. 1 is a schematic perspective view showing an appearance of a display device according to the present invention. In the figure, reference numeral 1 denotes a display device, which displays an image on a display surface 2 by a display panel provided in front of a main body portion having a substantially rectangular plate shape. The main body portion of the display device 1 is supported by a stand provided on the back so that the display surface 2 is substantially vertical on a desk or on the floor, and the display surface 1 is provided above the main body portion of the display device 1. A sensor unit 4 for measuring display intensity such as brightness and chromaticity of the peripheral part 2 and ambient temperature is built in and attached.

  FIG. 2 is a cross-sectional view taken along the line A-A ′ of the display device 1 shown in FIG. 1. In the figure, a display panel 3 having a display surface 2 displays an image in the direction of the arrow shown, and is supported by a housing 5 that covers a part of the display surface 2 and the back surface of the display panel 3. The shaded area at the top of the display panel 3 is a frame material that reinforces the display panel 3, and no image is displayed in this area. The sensor unit 4 includes an optical sensor 4 a corresponding to the display intensity measuring unit of the present invention and a temperature sensor 4 b corresponding to the temperature measuring unit of the present invention. At least the optical sensor 4 a is attached to the housing 5 of the display surface 2. It is installed to face the part to be covered. The optical sensor 4a measures the display intensity such as the luminance and chromaticity of the display surface 2 facing, and the temperature sensor 4b measures the surrounding ambient temperature. The optical sensor 4a and the temperature sensor 4b are provided on the circuit board 4c, and measurement information is sent to an MPU (Micro-Processing Unit) 7 described later via the signal line 4d. In addition, a part of the display surface 2 facing the sensor unit 4 is covered with the housing 5 in order to block outside light that becomes measurement noise. With this configuration, the sensor unit 4 is operated. Not only does the mechanism material become unnecessary, but it is also possible to eliminate that the sensor unit 4 obstructs the visibility of the user by hiding the image displayed on the display surface 2. In FIG. 2, the optical sensor 4a and the temperature sensor 4b are provided on the same circuit board. However, the present invention is not limited to this, and a temperature approximating the temperature of the display area that the optical sensor 4a faces is measured. What is necessary is just to install the temperature sensor 4b in the position which can do.

  A circuit board 6b provided with a temperature sensor 6a is provided almost at the center of the back surface of the display panel 3, and measurement information is sent to an MPU 7 to be described later via a signal line 6c. Considering the visibility of the user, the temperature sensor 6a and the circuit board 6b are provided on the back surface of the display panel 3. However, if the temperature sensor 6a and the circuit board 6b are configured so as not to disturb the visibility of the user such as a transparent material. It may be provided on the display surface 2.

1-2. Circuit Block FIG. 3 is a circuit block diagram showing the configuration of an apparatus for executing the display intensity estimation method according to the present invention. The display intensity estimation method according to the present invention includes the display device 1, the optical sensor 4a, the temperature sensor 4b, and the temperature sensor 6a described above, and the external optical sensor 30 for manually measuring the display intensity at the center of the display surface 2. The information processing apparatus 20 such as a personal computer for controlling these devices can be used.

  The display device 1 includes a display panel 3, an MPU 7, an image signal input unit 9, a data communication unit 10, a drive circuit 8, and the like. The image signal input unit 9 of the display device 1 has a connection terminal connected to the information processing device 20 via a cable, acquires an image signal corresponding to the input intensity from the information processing device 20, and the display device 1 An image is displayed on the display surface 2 of the display panel 3 based on the image signal. The image signal input to the image signal input unit 9 may be either an analog or digital signal format. Further, the data communication unit 10 of the display device 1 has a connection terminal connected to the information processing device 20 via a cable such as a USB (Universal Serial Bus), and a measurement command input from the information processing device 20. The data such as the measured value is output to the information processing device 20.

  The MPU 7 is connected to each part in the display device 1 via a bus and controls these operations to execute various processes such as image display. The drive circuit 8 is controlled by the MPU 7 and drives the display panel 3 based on the image signal input to the image signal input unit 9. The sensor unit 4 attached to the display device 1 includes an optical sensor 4a, a temperature sensor 4b, and the like. The optical sensor 4a includes a light receiving element such as a phototransistor, an A / D conversion circuit, and the like, and the light receiving element outputs in accordance with display intensity such as luminance or chromaticity at the periphery of the display surface 2 of the display panel 3. The voltage to be converted is converted into a digital electric signal by an A / D conversion circuit and output. The temperature sensor 4b includes a semiconductor element such as a thermistor, an A / D conversion circuit, and the like, and the semiconductor element outputs according to the ambient temperature of the display surface 2 around the optical sensor 4a or the optical sensor 4a. The voltage is converted into a digital electric signal by an A / D conversion circuit and output.

  The external light sensor 30 measures display intensity such as luminance or chromaticity of the display surface 2 in the same manner as the light sensor 4 a of the sensor unit 4. However, it is not always attached to the display device 1 like the optical sensor 4a, but is used by being fixed to the approximate center of the display surface 2 only when measurement is performed. It is additionally used when the user periodically acquires related information such as a relative ratio between the display intensity at the center portion of the display surface 2 and the display intensity at the peripheral portion. The external light sensor 30 is connected to the data communication unit 24 of the information processing device 20 only when in use, and the display intensity measured by the external light sensor 30 is given to the information processing device 20 as digital data.

  The information processing device 20 includes a storage unit 21, a CPU (Central Processing Unit) 22, an image signal output unit 23, a data communication unit 24, and the like. The image signal output unit 23 of the information processing device 20 has a connection terminal connected to the display device 1 via a cable, and outputs an image signal corresponding to the input intensity to the display device 1. In addition, the data communication unit 24 of the information processing device 20 has a connection terminal connected to the display device 1 via a cable such as a USB, and transmits and receives data to and from the display device 1. The CPU 22 is connected to each unit in the information processing device 20 via a bus, and controls the operation of each unit.

  The storage unit 21 stores various programs such as an operating system, application programs, and control programs, and data used by these programs or data generated by these programs. In the present embodiment, the storage unit 21 further stores display intensity related data 21a, display efficiency temperature characteristic data 21b, temperature data 21c, a calibration program 21d for calibration processing, and the like. The display intensity related data 21a is data corresponding to the related value of the present invention, and the display efficiency temperature characteristic data 21b is data corresponding to the display efficiency group of the present invention.

  Even if the drive circuit 8 is driven by a preset method when the display panel 1 is changed over time due to continuous use of the display device 1 and the display characteristics of the display panel 3 are slightly changed, it is ideal. An image may not be displayed with the display intensity. For this reason, it is necessary to perform a calibration process for updating the drive circuit 8 in accordance with the display intensity of the display panel 3 that has changed. In the calibration process, the display intensity of the display surface 2 of the display device 1 is measured using the optical sensor 4a, and the drive circuit 8 is updated so as to obtain an ideal display intensity. The calibration process is preferably performed based on the display intensity at the center of the display surface 2, but the optical sensor 4 a can measure only the display intensity at the periphery of the display surface 2. Therefore, the storage unit 21 stores display intensity related data 21a in which the display intensity at the center of the display surface 2 and the display intensity at the peripheral part are stored in association with each other, and the calibration process is performed as follows. Based on the display intensity related data 21a, the display intensity of the central part is obtained or calculated from the display intensity of the peripheral part of the display surface 2 measured by the optical sensor 4a, and is performed based on the display intensity of the central part. .

  FIG. 4 is a schematic diagram showing an example of the display intensity related data 21a. The display intensity related data 21a stores a related value that associates the display intensity of the peripheral portion of the display surface 2 measured by the optical sensor 4a with the display intensity of the central portion of the display surface 2 measured by the external light sensor 30. It is a table. When the display device 1 and the external light sensor 30 are manufactured and sold as a set, the display intensity related data 21a is obtained by surrounding the measurement values by the light sensor 4a and the external light sensor 30 in the development process or the manufacturing process. It may be created in advance in association with the temperature. When the display intensity related data 21a is created in the development process or the manufacturing process, the created display intensity related data 21a may be provided by being recorded on a recording medium such as a CD-ROM, or the display device 1 (not shown). You may make it memorize | store in the storage area. The user can also update the display intensity related data 21a using the optical sensor 4a and the external optical sensor 30.

  In the display intensity related data 21a, the display intensity at the center of the display surface 2 and the display intensity at the periphery are stored as tristimulus values (X, Y, Z values). In the display intensity related data 21a shown in FIG. 4, the tristimulus values of the display intensity measured by the optical sensor 4a are XSn, YSn, ZSn (n = 0 to 8), and the tristimulus of the display intensity measured by the external light sensor 30 is used. Values are described as XRn, YRn, ZRn (n = 0-8). When the display panel 3 displays 256 gradations, the display intensity related data 21a stores the results of discrete measurements in about nine steps as shown in the figure, and stores them in one measurement floor. For each tone level, the ratio of the measured value of the optical sensor 4a to the measured value of the external optical sensor 30 (XRn / XSn, Xsn, YSn, ZSn) for each X, Y, Z value YRn / YSn, ZRn / ZSn) are stored in association with each other. Note that the display intensity related data 21a actually stored in the storage unit 21 may not include the item of the measured gradation level shown in FIG. Further, the ratio (XRn / XSn, YRn / YSn, ZRn / ZSn) of the measured value of the optical sensor 4a with respect to the measured value of the external optical sensor 30 is stored in association with the measured values (XSn, YSn, ZSn) of the optical sensor 4a. However, the present invention is not limited to this, and the measurement value (XRn, YRn, ZRn) of the external optical sensor 30 is simply associated with the measurement value (XSn, YSn, ZSn) of the optical sensor 4a and stored. Also good.

  When the calibration process is performed using the calibration program 21d, the display intensity of the peripheral part of the display surface 2 is measured by the optical sensor 4a, and the measured display intensity is converted into tristimulus values (XSn, YSn, ZSn). By converting and referring to the display intensity related data 21a, it is possible to acquire the tristimulus values (XRn, YRn, ZRn) of the display intensity at the center. At this time, the tristimulus value related to the display intensity measured by the optical sensor 4a is not included in the display intensity related data 21a, and the tristimulus value of the central display intensity cannot be directly acquired. First, linear interpolation processing is performed based on the values stored in the display intensity related data 21a to obtain the tristimulus values of the display intensity at the center.

  Further, the storage unit 21 stores display efficiency temperature characteristic data 21b in which temperature characteristics of display efficiency are stored for each of the central part and the peripheral part of the display surface 2 as shown in FIG. FIG. 6 is a schematic diagram in which the display efficiency temperature characteristic data 21b is graphed. As shown in FIG. 5, the storage unit 21 may store the display efficiency of the central part and the peripheral part of the display surface 2 for each temperature, or store a calculation formula approximated to the schematic diagram of FIG. Also good. The storage unit 21 stores the temperature of the central part and the peripheral part of the display surface 2 when the display intensity related data 21a is created as temperature data 21c. When the calibration process is performed, the temperatures of the central portion and the peripheral portion of the display surface 2 are measured by the temperature sensor 4b and the temperature sensor 6a, and how much the display efficiency is based on the display efficiency temperature characteristic data 21b and the temperature data 21c. By determining whether or not the fluctuation has occurred and correcting the obtained tristimulus value of the display intensity of the central part with the obtained fluctuation rate, the tristimulus value of the display intensity of the central part is accurately estimated.

The display intensity correction will be described in detail. The central temperature Tc0 and the peripheral temperature Ta0 (◯ in FIG. 6) stored as the temperature data 21c in the storage unit 21 are temperatures measured by the temperature sensor 4b and the temperature sensor 6a, respectively, when the display intensity related data 21a is created. . At the time of the calibration process, the central temperature Tc1 and the peripheral temperature Ta1 (■ in FIG. 6) are measured again by the temperature sensor 4b and the temperature sensor 6a, respectively. Next, the display efficiencies Ec (Tc0), Ec (Tc1), Ea (Ta0), and Ea (Ta1) of the center temperature Tc0, Tc1 and the peripheral temperature Ta0, Ta1 are used using the display efficiency temperature characteristic data 21b. get. Then, how much the display efficiency has changed from the creation of the display intensity related data 21a to the calibration process is obtained by the following equation. The display efficiencies Ec (Tc0) and Ea (Ta0) correspond to the first display efficiency of the present invention, and the display efficiencies Ec (Tc1) and Ea (Ta1) correspond to the second display efficiency of the present invention. .

Display efficiency variation rate Rc = Ec (Tc1) / Ec (Tc0) in the center (Equation 1)

Peripheral display efficiency fluctuation rate Ra = Ea (Ta1) / Ea (Ta0) (2)

Furthermore, the ratio of the fluctuation rate between the central part and the peripheral part is obtained by the following equation.

Display efficiency fluctuation ratio Rac = Rc / Ra (Equation 3)

By multiplying the tristimulus value of the display intensity at the central portion where the fluctuation rate ratio Rac is acquired, correction that takes temperature into account is performed.

1-3. Creation or update processing of display intensity related data 21a (execution of correlation step)
FIG. 7 is a flowchart showing a procedure of processing for creating or updating the display intensity related data 21a corresponding to the correlation step of the present invention. The process of creating or updating the display intensity related data 21a is performed before the calibration process. When an instruction to execute this process is given by an operation on the information processing device 20, first, the display intensity display data 21a is displayed. A message requesting attachment of the external light sensor 30 is displayed at the center of the display surface 2 of the apparatus 1 (step S1). At this time, it is preferable to display a graphic or symbol indicating the mounting position of the external light sensor 30 in the center of the display surface 2 together with the message. Thereafter, the external light sensor 30 is attached to the center of the display surface 2, and it is checked whether or not the external light sensor 30 has been attached by, for example, examining whether or not an operation for notifying the completion of the attachment has been performed (step) S2) If the attachment is not completed (S2: NO), the process returns to step S1 to continue displaying the message, and waits until the attachment is completed.

  When the attachment of the external light sensor 30 to the center of the display surface 2 is completed (S2: YES), the gradation level as the input intensity is set to one of the predetermined measurement gradation levels (step S3). For example, in the case of the display intensity related data 21a shown in FIG. 4, it is necessary to change the measurement gradation level in nine steps, and in step S3, one of the nine measurement gradation levels is measured. Set to the key level.

  Next, the display intensity of the peripheral portion of the display surface 2 is measured by the optical sensor 4a to obtain a measurement value (step S4), and the obtained measurement values of the R, G, and B values are obtained as X, Y, and Z values. Conversion into tristimulus values (step S5). Further, the display intensity of the central portion of the display surface 2 is measured by the external light sensor 30 to obtain a measured value (Step S6), and the obtained measured values of R, G, and B values are X, Y, and Z values. Are converted into tristimulus values (step S7). The conversion from RGB values to tristimulus values is performed in the conventional manner.

  Next, the ratio XRn / XSn, YRn / YSn, ZRn / ZSn of the measured values XSn, YSn, ZSn of the optical sensor 4a with respect to the measured values XRn, YRn, ZRn of the external optical sensor 30, that is, the relative ratio is calculated (step S8). ) And stored as display intensity related data 21a in the storage unit 21 (step S9). It is checked whether or not the storage of the relative ratio has been completed for all the measured gradation levels (step S10). If not completed (S10: NO), the process returns to step S3, and the unprocessed measured gradation levels are obtained. Steps S4 to S9 are repeated. When the processing has been completed for all the measured gradation levels (S10: YES), the temperature sensor 6a measures the central temperature Tc0, and the temperature sensor 4b measures the peripheral temperature Ta0 (step S11). It memorize | stores in the memory | storage part 21 as temperature data 21c (step S12). Thereafter, a termination process including a process for returning the display on the display panel 3 and a process for displaying a message prompting the removal of the external light sensor 30 is performed (step S13), and the process is terminated.

  According to the above procedure, the temperatures of the central portion and the peripheral portion of the display surface 2 at the time of creating or updating the display intensity related data 21a can be stored, and the display intensity related data 21a and the temperature data 21c can be stored when performing the calibration process. , The display intensity at the center can be estimated from the display intensity around the display surface 2 measured by the optical sensor 4a. The correlation step may be executed only when the user purchases the display device or at long intervals such as every other year.

1-4. Calibration process (execution of calibration steps)
FIG. 8 is a flowchart showing the procedure of the calibration process corresponding to the calibration step of the present invention. The calibration step is required to complete the above-described correlation step, and is executed every other day or at intervals shorter than the correlation step every time the display device is used. In the calibration process, first, the gradation level corresponding to the input intensity for image display is set to 0 (step S21). Next, the display intensity of the peripheral portion of the display surface 2 is measured by the optical sensor 4a to obtain a measured value (step S22), and the measured values of the measured R, G, and B values are X, Y, and Z values. Conversion into tristimulus values (step S23).

  Next, it is checked whether or not the tristimulus values obtained in step S23 are included in the values stored in the display intensity related data 21a in the storage unit 21 (step S24). (S24: YES), the display intensity of the corresponding central portion is acquired from the display intensity related data 21a (step S26), and if not included (S24: NO), linear interpolation processing is performed (step S25). The display intensity at the center is calculated.

  After step S26, the temperature sensor 6a measures the central temperature Tc1 and the temperature sensor 4b measures the peripheral temperature Ta1 (step S27), and corresponds to the temperatures Tc1 and Ta1 from the display efficiency temperature characteristic data 21b. The display efficiencies Ec1 and Ea1 to be acquired and the display efficiencies Ec0 and Ea0 corresponding to the temperatures Tc0 and Ta0 stored as the temperature data 21c are also acquired (step S28). Further, the display efficiency variation rate ratio Rac is obtained by the above-described method, and the display intensity acquired in step S26 is corrected (step S29).

  Since the display intensity corrected in step S29 is a tristimulus value of X, Y, and Z values, it is converted into display intensity of R, G, and B values (step S30) and converted into R, G, and B values. The display intensity at the center is temporarily stored in the storage unit 21 for use in update processing of the drive circuit 8 described later (step S31). Thereafter, it is checked whether or not the acquisition of the display intensity at the central portion of the display surface 2 has been completed for all the gradation levels that can be displayed on the display panel 3 (step S32). (S32: NO), the gradation level is changed by one step (step S33), the process returns to step S22, and the processes of steps S22 to S31 are repeated for all the gradation levels.

  When the acquisition of the display intensity at the central portion of the display surface 2 for all the gradation levels is completed (S32: YES), the central portion of the display surface 2 for all the gradation levels stored in the storage unit 21 in step S31. The drive circuit 8 is updated so as to drive at the ideal display intensity based on the display intensity (step S34). After the updating process of the drive circuit 8 is completed in step S34, an ending process including a process for restoring the display on the display panel 3 is performed (step S35), and the calibration process is ended.

  As an update process of the drive circuit 8, for example, there is a method of updating an LUT for gradation level conversion provided in the drive circuit 8. FIG. 9 is a flowchart showing a procedure for updating the LUT provided in the drive circuit 8, and is a process performed in step S34 of the flowchart of FIG. The ideal display intensity for the gradation level k is XTk (k = 0 to 255), and the display intensity acquired for the gradation level j is the display intensity at the center of the display surface 2 stored in step S31. Let it be XTj (j = 0 to 255).

  In the update process of the LUT provided in the drive circuit 8, first, the difference (XTk−XTj) between the ideal display intensity XTk and the acquired display intensity XTj is calculated for all combinations (step S41). A combination of gradation levels k and j that minimizes the absolute value | XTk−XTj | is extracted (step S42). From the extraction result, the gradation level k is input to the table, the corresponding gradation level j is stored as an output of the table in the LUT (step S43), and the update process is terminated.

  In the display intensity estimation method using the display device 1 and the information processing apparatus 20 having the above-described configuration, the display intensity and display of the peripheral portion of the display surface 2 are stored in the storage unit 21 of the information processing apparatus 20 as the display intensity related data 21a. The display intensity at the center of the surface 2 is stored in association with it, and when processing such as calibration is performed, the display intensity at the periphery of the display surface 2 is measured and displayed from the display intensity related data 21a. By acquiring or calculating the display intensity at the center of the surface 2, it is possible to perform processing such as calibration with high accuracy from the measurement value of the optical sensor 4 a, and thus it is possible to easily realize automation of these processing. .

  In the display intensity estimation method using the display device 1 and the information processing device 20 having the above configuration, the temperature of the peripheral portion of the display surface 2 and the center of the display surface 2 are stored in the storage unit 21 of the information processing device 20 as temperature data 21c. When the temperature of the part is stored and the processing such as calibration is performed, the temperature of the peripheral part of the display surface 2 and the temperature of the central part of the display surface 2 are measured and acquired from the display intensity related data 21a or In order to correct the calculated display intensity at the center of the display surface 2 based on the temperature data 21c and the display efficiency temperature characteristic data 21b, for example, when the display intensity of a portion covered with the housing 5 and having a significant temperature rise is measured. Even if it exists, it becomes possible to estimate the display intensity of the center part of the display surface 2 with high accuracy without depending on the temperature.

  In the present embodiment, the display intensity at the center of the display surface 2 is acquired and calculated for the calibration process. However, the present invention is not limited to this, and the display characteristics of the display device 1 can be checked. It is good also as a structure performed for the other objectives. The optical sensor 4a is built in the display device 1. However, the present invention is not limited to this. The optical sensor 4a is a device different from the display device 1, and the optical sensor 4a is attached to the display device 1 for measurement. It is good also as a structure to perform. Further, although the information processing device 20 performs the calibration process and the display intensity related data 21a update process, the present invention is not limited to this, and the display device 1 may be configured to perform these processes. Further, although the measurement value of the temperature sensor 6a provided at the center of the back surface of the display panel 3 is regarded as the temperature of the center portion of the display surface 2, the processing is remarkably performed between the back surface of the display panel 3 and the display surface 2. When a temperature difference occurs, correction for eliminating the temperature difference may be appropriately performed. A cooling fan may be provided for the purpose of cooling the temperature in the display device, and the temperature difference may be remarkably generated depending on the operating state of the cooling fan. In such a display device, the correction amount may be calculated based on the operating status of the cooling fan such as the number of revolutions, and the temperature difference between the back surface of the display panel 3 and the display surface 2 may be eliminated.

1-5. Modification FIG. 10 is a schematic diagram showing display intensity related data 21a according to a modification of the present embodiment. The display intensity related data 21a according to the modification includes the measurement gradation level, the display intensity of the peripheral part of the display surface 2 measured by the optical sensor 4a, and the display intensity of the central part of the display surface 2 measured by the external light sensor 30. Is a table stored as a related value in association with the relative ratio of the display intensity measured by the optical sensor 4a, for example, the luminance value is YSn (n = 0 to 8), and the luminance measured by the external optical sensor 30. Values are listed as YRn (n = 0-8). The ratio YRn / YSn of the measurement value of the optical sensor 4a with respect to the measurement value of the external optical sensor 30 is stored in association with each measurement gradation level.

  When the calibration process is performed using the calibration program 21d, first, the relative ratio associated with the measurement gradation level when the luminance value of the peripheral portion of the display surface 2 is measured by the optical sensor 4a is displayed intensity. The luminance value of the central portion can be estimated by multiplying the display intensity of the peripheral portion of the display surface 2 acquired from the related data 21a and measured by the optical sensor 4a by the acquired relative ratio.

  It has been confirmed by experiments of the inventors that the tendency of luminance unevenness or color unevenness that occurs in the periphery of the display surface changes according to the input intensity. According to the modification, since the relative ratio between the display intensity at the center of the display surface and the display intensity at the periphery of the display surface is obtained as the input intensity, the display intensity at the center of the display surface is more accurately obtained. Can be estimated.

2. Second Embodiment FIG. 11 is a block diagram showing a configuration of an apparatus for executing a display intensity estimation method according to another example of the present embodiment. In FIG. 11, the same reference numerals as those in FIG. The difference between FIG. 11 and FIG. 3 is that the temperature sensor 6 a for measuring the temperature of the central portion of the display surface 2 is deleted and the temperature related data 11 is provided in the display device 1.

2-1. Configuration FIG. 12 is a schematic diagram illustrating an example of the temperature-related data 11. The temperature-related data 11 is a table in which the temperature of the peripheral portion of the display surface 2 measured by the temperature sensor 4b and the temperature of the central portion of the back surface of the display panel 3 measured by another temperature sensor are stored in association with each other. This measurement may be made in advance by a development process or a manufacturing process. When the temperature-related data 11 is created in the development process or the manufacturing process, the created temperature-related data 11 may be recorded and provided on a recording medium such as a CD-ROM.

  In the flowchart showing the processing procedure for creating or updating the display intensity related data 21a shown in FIG. 7, the measured value of the temperature sensor is acquired in step S11, and stored in the storage unit 21 as the temperature data 21c in step S12. However, in this embodiment, the temperature of the peripheral part is measured by the temperature sensor 4b, the temperature of the central part corresponding to the measured temperature of the peripheral part is obtained from the temperature-related data 11, and the peripheral part measured in the storage unit 21 is measured. The temperature of the part and the acquired temperature of the central part are stored as temperature data 21c. Furthermore, in the flowchart showing the procedure of the calibration process shown in FIG. 8, the measured value of the temperature sensor is acquired in step S27, and the corresponding display efficiency is acquired from the display efficiency temperature characteristic data 21b in step S28. In this embodiment, the temperature of the peripheral portion is measured by the temperature sensor 4b, the temperature of the central portion corresponding to the measured temperature of the peripheral portion is acquired from the temperature-related data 11, and the measured temperature of the peripheral portion is acquired. Display efficiency corresponding to the temperature at the center is acquired from the display efficiency temperature characteristic data 21b.

  Thus, by providing the temperature-related data 11 in the display device 1, the temperature sensor 6a for measuring the temperature of the central portion of the display surface 2 becomes unnecessary, and the circuit configuration for the present invention is minimized. It becomes possible. In this embodiment, the temperature of the peripheral portion of the display surface 2 is measured, and the temperature of the central portion of the display surface 2 is obtained from the measured temperature. However, the present invention is not limited to this. You may make it measure temperature and acquire the temperature of the peripheral part of the display surface 2 from the measured temperature, measure the temperature of the location which is neither the center part nor the peripheral part of the display surface 2, and display from the measured temperature You may make it acquire the temperature of the center part of the surface 2, and a peripheral part.

3. Third Embodiment FIG. 13 is a schematic diagram showing display efficiency data for executing a display intensity estimation method according to another example of the present embodiment. In the above embodiment, the display efficiency data shown in FIG. 5 is used. The difference from this is that the display efficiency of the central portion and the peripheral portion of the display surface 2 is stored for each temperature, and the attitude of the display surface. It is in the point which memorized information.

3-1. Configuration Some display devices can be used for landscape display in which the display surface can be displaced by 90 ° and the display screen has a horizontal longitudinal direction, and portrait display in which the display surface longitudinal direction is vertical. . Especially in the medical field, since the frequency of displaying a vertically long X-ray image is high, the use in portrait display occupies most. However, there is a problem that changing the orientation of the display surface changes the bias of the constituent members of the display panel in the direction of gravity and changes the display efficiency. A specific example of the problem will be described in the case where the display panel is a liquid crystal panel and the backlight is a CCFL tube (Cold Cathode Fluorescent Lamp). There are two types of CCFL tube installation methods: a direct type arrangement on the back of the display panel and an edge type arrangement on the back and around the display panel, both of which are along the longitudinal direction of the display surface. Often placed. Non-volatile gas and mercury are enclosed in the CCFL tube as a luminescent material, and in the landscape display, gravity is applied evenly to the CCFL tube, so the enclosed luminescent material is also distributed uniformly, but the portrait display Then, the luminescent material distribution is biased, and as a result, the luminous efficiency differs between the upper and lower sides of the CCFL tube.

  FIG. 13 is a schematic diagram showing an example of display efficiency temperature characteristic data in the present embodiment, in which the temperature characteristic of display efficiency is stored together with the orientation information of the display surface for each of the central part and the peripheral part. The display efficiency temperature characteristic data may be created by switching the display device to both landscape display and portrait display in the development stage or manufacturing process, and creating display efficiency of each display area for each ambient temperature in advance. As shown in FIG. 13, the storage unit 21 may store the display efficiency for each temperature for each display posture, or may store an approximate expression derived from FIG.

  In the flowchart showing the calibration process shown in FIG. 8, the display efficiency corresponding to the measurement value of the temperature sensor is acquired from the display efficiency temperature characteristic data in step S28. In this embodiment, the measurement value of the temperature sensor is obtained. In addition, the display surface orientation is also acquired, and the display efficiency corresponding to the measured temperature and the display surface orientation is acquired from the display efficiency temperature characteristic data. The display surface orientation information may be acquired automatically by incorporating a sensor for posture detection, such as a gravity sensor, into the display device, or an OSD (On Screen Display) or calibration program provided in the display device. It may be obtained manually by the user.

  Thus, by providing the display efficiency temperature characteristic data for each orientation of the display surface, it is possible to accurately estimate the display intensity at the center of the display surface without depending on the orientation of the display surface. In this embodiment, the display efficiency temperature characteristic data in two orientations of the landscape display and portrait display devices are stored. However, the present invention is not limited to this, and the display efficiency temperature characteristic data in other orientations such as a tilt is stored. You may make it memorize | store.

DESCRIPTION OF SYMBOLS 1 Display apparatus 2 Display surface 3 Display panel 4 Sensor part 4a Optical sensor (display intensity measurement means)
4b Temperature sensor (temperature measurement means)
4c Circuit board 4d Signal line 5 Housing 6a Temperature sensor (temperature measuring means)
6b Circuit board 6c Signal line 7 MPU
8 Drive Circuit 9 Image Signal Input Unit 10 Data Communication Unit 11 Temperature Related Data 20 Information Processing Device (Computer)
21 storage unit 21a display intensity related data (related value)
21b Display efficiency temperature characteristic data (display efficiency group)
21c Temperature data 21d Calibration program 22 CPU
23 Image signal output unit 24 Data communication unit 30 External light sensor

Claims (4)

Display of a display area that does not face the display intensity measuring means on a display device comprising a display panel, display intensity measuring means for measuring the display intensity of the display surface of the display panel, and temperature measuring means for measuring temperature In the display intensity estimation method for estimating the intensity,
Wherein the display efficiency of the display area facing the display intensity measuring means, the display intensity and a display efficiency of the display area not facing the measuring means, and display efficiency group display area of the display surface for different temperatures pre Me memory In addition, a related value for associating the display intensity of the display area facing the display intensity measuring unit and the display intensity of the display area not facing the display intensity measuring unit is stored in advance, and the related value is stored. A correlation step of measuring in advance the temperature of an arbitrary display area on the display surface when
After the correlation step, the temperature measuring means measures the temperature of an arbitrary display area of the display surface, the display intensity measuring means measures the display intensity of the display area facing the display intensity measuring means, Based on the display intensity of the display area facing the measured display intensity measuring means and the previously stored related value, the display intensity of the display area not facing the display intensity measuring means is estimated and stored in advance during the correlation step. The display stored in advance includes a first display efficiency consisting of the display efficiency corresponding to the temperature of the display area facing the display intensity measuring means determined from the temperature of the arbitrary display area and the temperature of the display area not facing the display intensity measuring means. determined from the efficiency group, the temperature and the display intensity measurement hand display area facing the display intensity measuring means obtained from the temperature of any of the display area that the measured Determined from the display efficiency group the second display efficiency and a display efficiency corresponding to the temperature of the display area does not face the said pre-stored in these first, determine the rate of change from a comparison of the second display efficiency was obtained the A display intensity estimation method comprising a calibration step of correcting display intensity of a display area not facing the estimated display intensity measurement means based on a change rate.
Display of a display area that does not face the display intensity measuring means on a display device comprising a display panel, display intensity measuring means for measuring the display intensity of the display surface of the display panel, and temperature measuring means for measuring temperature In the display intensity estimation method for estimating the intensity,
Wherein the display efficiency of the display area facing the display intensity measuring means, the display intensity and a display efficiency of the display area not facing the measuring means, and display efficiency group display area of the display surface for different temperatures pre Me memory In addition, a related value for associating the display intensity of the display area facing the display intensity measuring unit and the display intensity of the display area not facing the display intensity measuring unit is stored in advance, and the related value is stored. A correlation step of measuring in advance the temperature of an arbitrary display area of the display surface, obtaining a first display efficiency corresponding to the temperature from the stored display efficiency group, and storing this;
After the correlation step, the temperature measuring means measures the temperature of an arbitrary display area of the display surface, the display intensity measuring means measures the display intensity of the display area facing the display intensity measuring means, Based on the measured display intensity of the display area facing the display intensity measuring means and the related value stored in advance, the display intensity of the display area not facing the display intensity measuring means is estimated and stored in advance in the correlation step. A first display efficiency comprising a display efficiency corresponding to a temperature of the display area facing the display intensity measuring means determined from the temperature of the arbitrary display area and a temperature of the display area not facing the display intensity measuring means, not facing to the temperature and the display intensity measuring means of the display area facing the display intensity measuring means obtained from the temperature of the arbitrary display area of measurement display area of Obtains a second display efficiency and a display efficiency corresponding to the time from the pre-stored display efficiency group, these first, determine the rate of change from a comparison of the second display efficiency, it is the estimated based on the obtained change rate A display intensity estimation method comprising a calibration step of correcting the display intensity of a display area not facing the display intensity measuring means.
The display intensity estimation method according to claim 1, wherein the temperature of any display area on the display surface is measured, and the temperature of another display area is estimated from the measured temperature of the display area.
A display panel, a display intensity measuring means for measuring the display intensity of the display surface of the display panel, is installed on a computer connected to a display device and a temperature measuring means for measuring the temperature, pre-Symbol Display on the computer In a computer program for estimating the display intensity of a display area that does not face the intensity measuring means,
In the computer, the display efficiency of the display area facing the display intensity measuring means and the display efficiency of the display area not facing the display intensity measuring means are set as the display efficiency group of the display area of the display surface at different temperatures. Te allowed to pre Me storage, and display the intensity of the display area that faces the display intensity measuring means of the display surface, it causes previously stored related values that associates the display intensity of the display region not facing the display intensity measuring means A correlation step for preliminarily storing the temperature of an arbitrary display area of the display surface at the time of preliminarily storing the related value;
After the correlation step, the temperature measuring means measures the temperature of an arbitrary display area of the display surface, the display intensity measuring means measures the display intensity of the display area facing the display intensity measuring means, Based on the measured display intensity of the display area facing the display intensity measuring means and the previously stored related value, the display intensity of the display area not facing the display intensity measuring means is estimated and stored in advance in the correlation step. a first display efficiency and a display efficiency corresponding to the temperature of the display region not facing to the temperature and the display intensity measuring means of the display area facing the display intensity measuring means obtained from the temperature of any of the display area that was the prestored let determined from the display efficiency group, the temperature of the display region facing the display intensity measuring means obtained from the temperature of any of the display area that the measured Let obtains a second display efficiency and a display efficiency corresponding to the temperature of the display region not facing the intensive measurement means from the pre-stored display efficiency group, the change rate from a comparison of these first, second display efficiency A computer program for executing a calibration step of correcting the display intensity of a display area that does not face the estimated display intensity measuring means based on the calculated change rate.