JP2002169525A - Display and display time measurmemt method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display with which display time can be measured without using another instrument and the display time measured till then can be stored even when the power source supply from the outside is cut off and with which the measurement precision of the display time can be improved, and to provide a display time measurement method. SOLUTION: In a display part 1, a display time measuring part 9 measures the period in which a video is being displayed. A control section 4 reads the measured display time from the display time measuring part 9, and writes the time into a nonvolatile memory 7. A sensor 6 detects the interruption of an external power supply and transmits the information to the control section 4. The control section 4, which has received information on the power source cutoff, writes the counted value corresponding to the display time which the display time measuring part 9 was measuring until then into a nonvolatile memory 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device such as a plasma display or a projection display, and a display time measuring method for measuring a display time of the display device.

[0002]

2. Description of the Related Art Conventionally, regarding the life of a display device used as a man-machine interface, a user of the device equipped with the display device looks at the brightness and contrast of the display portion of the display device. Judgment by that. As another method, the approximate life of the display device is estimated from the installation start time or use start time of the device.

However, in order to accurately determine the life of a display device visually, specialty is required. Also,
In a device that operates the display device only when necessary, if the life of the display device is estimated from the installation start time of the device or the like, a large error occurs in the estimated life. As a result, it is not easy to determine the replacement time of the display device or the maintenance and inspection time, and there is a problem that the reliability of the entire device is reduced and the maintenance and inspection cost is increased.

In order to solve the above-mentioned problem, for example, Japanese Patent Application Laid-Open No. 8-249509 discloses an information processing apparatus having a function of monitoring the life of a display device. FIG. 4 is a block diagram showing a configuration of the information processing apparatus. In FIG. 4, an information processing device having a life monitoring function of a display device includes an information processing device 32,
The display device 30 includes a display device 30 that displays display data from the information processing device 32, a display control unit 31 that controls display data of the display device 30, and a display control switch 8 that turns on and off the display of the display device 30. ing. The display control unit 31 further includes a measurement counter 33 that measures a display time of the display device 30;
The nonvolatile memory 7 for storing the display time measured by the measurement counter 33 is provided.

Next, the operation of the information processing apparatus having the above-mentioned display device life monitoring function will be described. When the display control switch 8 is turned on (ON), the display power from the information processing device 32 is displayed on the display device 30 by controlling the power supply of the display device 30 via the display control unit 31. At this time, the measurement counter 33 counts up, for example, every second, with the predetermined interval as a unit of measurement, and measures the display time of the display device 30. Then, when the display control switch 8 is turned off (OFF), the display on the display device 30 is terminated, and the count value of the measurement counter 33 is stored in the nonvolatile memory 7 as the display time. Next, when the display control switch 8 is turned on again (ON), first, the count value indicating the previous display time stored in the nonvolatile memory 7 is read into the measurement counter 33,
The count value is increased at predetermined intervals. Then, when the display control switch 8 is turned off (OFF), the display on the display device 30 is terminated, and the count value at that time is written in the nonvolatile memory 7. By repeating the above operation, the integrated value of the display time up to that time on the display device 30 can be stored in the nonvolatile memory 7. Therefore, even when the power of the information processing apparatus is not supplied, the integrated value of the display time can be maintained without disappearing.

Further, by providing the display control section 31 with means for presetting the life time of the display device 30 and alarm output means, the integrated value of the display time of the display device 30 exceeds the preset life time. sometimes,
Alarm can be output.

As described above, since the information processing apparatus has the life monitoring function, it is possible to easily determine the replacement time of the display device 30 and the maintenance and inspection time, and it is possible to reduce the maintenance and inspection cost. In addition, since the accurate operation time of the display device 30 is known, it is possible to determine whether the deterioration of the display function of the display device 30 is based on the life or other factors. Can be easily analyzed.

[0008]

However, the display device is not always used for a certain purpose. Specifically, devices used for monitoring systems such as power plants and substations, factories or traffic control, and information applications in public spaces such as airports are fixed at specific locations for a long time. Therefore, the display device is rarely used for other purposes. However, since devices used for exhibitions and events are used only for a short period of time, the display device may be used for other purposes at a later date. At this time, in the conventional structure, the display time cannot be measured by the display device alone, so that it is possible to accurately determine the replacement time of the display device or the maintenance and inspection time, which has conventionally been a problem. There are problems such as difficulty and difficulty in analyzing failures.

In the conventional information processing apparatus, the display time up to that point is stored in the nonvolatile memory 7 only when the display control switch 8 is turned off. for that reason,
During the display, that is, while the display control switch 8 remains on,
When power is not supplied to the information processing apparatus due to a power failure or the like, the display time measured up to that time cannot be stored in the nonvolatile memory 7. Therefore, there is a problem that the integrated value of the display time up to that time cannot be confirmed.

In addition, since the measurement counter 33 in the conventional information processing apparatus counts up for each measurement unit, the display time shorter than the measurement unit is consequently discarded. Therefore, every time the display on the display device 30 is performed, the truncated display time is accumulated in the display time measurement result as an error. In order to reduce the error, it is necessary to reduce the display time that is truncated. That is, in order to improve the measurement accuracy of the display time, it is necessary to reduce the measurement unit of the measurement counter 33. Since the maximum count value indicating the display time increases as a result of reducing the measurement unit, there is a problem that the memory capacity of the nonvolatile memory 7 for storing the count value has to be increased.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to measure the display time by a display device alone, and to be used when the external power supply is cut off. Also, a display device and a display time measuring method capable of storing the display time measured up to that time and improving the measurement accuracy of the display time without increasing the memory capacity of the nonvolatile memory are provided. Things.

[0012]

Means for Solving the Problems Claim 1 of the present invention
(A) measuring the display time during which the video is displayed to obtain a measured display time;
And (c) maintaining a voltage required for performing the step (b) when there is no external power supply.

The display time measuring method according to a second aspect of the present invention is the display time measuring method according to the first aspect, wherein (d) after the display of the image is temporarily terminated, Measuring a display time in which a new image is displayed to obtain a new measured display time; (e) measuring the display time stored in the step (b); and measuring the display time in the step (d). And (f) storing a value obtained by the addition as the measured display time.

According to a third aspect of the present invention, there is provided a display time measuring method according to the second aspect, wherein in the steps (a) and (d), the display time is measured. In the step (e), the display time is obtained in units of a predetermined interval, and in the step (e), one unit of the unit is added at a probability of 1/2 for each display of the video.

According to a fourth aspect of the present invention, there is provided a display time measuring method according to the third aspect, wherein the steps (d) to (f) form a set. Iteratively, in the step (e), one unit of the unit is added every other time of the execution.

According to a fifth aspect of the present invention, there is provided a display device for displaying an image, a display time measuring unit for measuring a display time of the image on the display unit, and a display time measuring unit for displaying the image. It is provided with a memory for storing the measurement results.

According to a sixth aspect of the present invention, in the display device according to the fifth aspect, the display unit intermittently performs video display a plurality of times, and the memory includes: The integrated value of the measurement result is stored each time the image is displayed.

The display device according to a seventh aspect of the present invention is the display device according to the sixth aspect, wherein the display time measuring section counts a count value at predetermined intervals of the display time. There is a counter that changes in one direction, and the measurement result is the count value.

The display device according to claim 8 of the present invention is the display device according to any one of claims 5 to 7, wherein the memory is non-volatile. .

The display device according to a ninth aspect of the present invention is the display device according to the eighth aspect, wherein the memory stores the measured display time when power is not supplied to the device. And a power supply unit for maintaining a voltage necessary for the operation.

A display device according to a tenth aspect of the present invention is the display device according to any one of the fifth to ninth aspects, wherein the display unit is a plasma display panel. Things.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram showing a configuration of the display device according to the first embodiment. The display unit 1 is a part that displays an image, and is configured by, for example, a plasma display panel (hereinafter abbreviated as “PDP”). The video signal processing unit 2 processes various types of video signals input from the outside and outputs a digital video signal having a predetermined number of pixels to the driving unit 3.
The drive unit 3 drives the display unit 1 based on the digital video signal received from the video signal processing unit 2. The power supply unit 5 receives supply of commercial power from the outside of the display device,
A necessary voltage is supplied to each of the display unit 1, the video signal processing unit 2, the driving unit 3, the control unit 4, the sensor 6, the nonvolatile memory 7, the display control switch 8, and the display time measuring unit 9. The sensor 6 detects that the external power supply to the power supply unit 5 has been turned off, and the control unit 4 monitors the information.

The display time measuring unit 9 receives start information of image display from the control unit 4 and measures the display time of the image on the display unit 1. Specifically, the display time measuring unit 9 has a counter that counts up at predetermined intervals while the image is displayed on the display unit 1, and measures the image display time with this counter. . In other words, the display time measuring unit 9 measures the time during which the display unit 1 is being driven by the driving unit 3.

The control unit 4 includes a video signal processing unit 2 and a driving unit 3
And the operation of the power supply unit 5. The control unit 4 also stores the display time of the image measured by the display time measurement unit 9, specifically, the count value of the display time measurement unit 9 in the nonvolatile memory 7.
Write to. The non-volatile memory 7 stores and retains information indicating a display time of an image and other states of the display device even when external power is not supplied to the display device. The display control switch 8 is a switch for turning on and off the display of an image on the display unit 1, and the control unit 4 monitors the information. In FIG. 1, the display time measuring unit 9 is provided outside the control unit 4, but the display time measuring unit 9 may be provided inside the control unit 4.

Next, an image display operation of the display device according to the first embodiment configured as described above will be described. When the display control switch 8 is turned on by user setting or the like, the control unit 4 receives the information, and the control unit 4
Performs various processes for displaying an image on the display unit 1. First, a video signal is input to the video signal processing unit 2 from outside the display device. The control unit 4 determines the type of the video signal. Then, the control unit 4 controls the operation of the video signal processing unit 2 according to the determination result of the type of the video signal. In the video signal processing unit 2,
Conversion to a predetermined number of pixels, contrast adjustment,
Performs image quality processing such as brightness adjustment, gamma correction, contour enhancement correction, and noise reduction. At this time, parameters for image quality adjustment are provided to the video signal processing unit 2 through the control unit 4 by user setting or the like. The drive unit 3 supplies an electric signal necessary for actually displaying an image to the display unit 1 based on the digital image signal given from the image signal processing unit 2. An image is displayed on the display unit 1 by the flow of such processing.

When the display control switch 8 is turned off,
The control unit 4 receives the information, and the control unit 4 operates to stop displaying the image on the display unit 1. Specifically, the control unit 4 controls the power supply unit 5, and displays the display unit 1, the video signal processing unit 2,
The power supply to the drive unit 3 is stopped. Therefore, the display unit 1
No image is displayed.

The power supply unit 5 supplies a necessary voltage to the display unit 1, the control unit 4, and the like. However, even when the external power supply is turned off, the control unit 4 and the nonvolatile memory 7 and the like remain for a certain period of time. In order to maintain the voltage required to keep operating, it incorporates a large-capacity capacitor and a battery. The control unit 4 receives the information of the external power cutoff detected by the sensor 6,
Processing for writing data required for backup, for example, image quality adjustment parameters set by the user, to the nonvolatile memory 7, and storing the video display time measured by the display time measuring unit 9 until the external power is turned off to the nonvolatile memory 7. Perform processing. Here, after the external power is turned off, the control unit 4
Toff is the time during which the voltage at which the device can operate is supplied.
And

FIG. 2 is a flowchart showing the operation of measuring the display time of the display device according to the first embodiment. A series of operations from measuring the display time of an image on the display device to storing the measured display time in the nonvolatile memory 7 will be described with reference to FIG.

First, in step S101, the control unit 4
Reads the integrated value Td recorded at a predetermined address in the nonvolatile memory 7. As described later, Td is an integrated value of the display time measured until the previous display on the display device. Then, the control unit 4 writes the integrated value Td into the display time measuring unit 9. Next, in step S102, the control unit 4 reads information recorded in the nonvolatile memory 7 at a predetermined address different from the integrated value Td, for example, information indicating the state of the display device. The information indicating the state of the display device is information at the time of previous use, and is, for example, an image quality adjustment parameter set by a user, a type of an input video signal, or 16: 9 display, 4: 3 display And other screen mode information.

Next, in step S103, the control unit 4
Returns the display device to the same state as in the previous use, using the information indicating the state of the display device in the last use read in step S102. Then, the control unit 4 controls the operations of the power supply unit 5, the display unit 1, the video signal processing unit 2, and the drive unit 3, and controls the display unit 1 as described above.
Start displaying video on. In particular, when the type of the input video signal is the same as the type of the video signal used last time,
Display can be started quickly by the information read from the nonvolatile memory 7. Note that, here, step S101
The processing from step S103 to step S103 is called display start processing.

Next, at step S104a, the display unit 1
Is displayed, the display time measuring unit 9 calculates the integrated value Td for each measurement unit using the predetermined interval Tr as a measurement unit.
Count up. Here, the integrated value Td written by the control unit 4 is an integrated value of the count value corresponding to the display time measured until the previous display, and is counted up at every predetermined interval Tr, as described above. Count value. In order to convert the integrated value Td into real time, the integrated value Td may be multiplied by the unit of measurement Tr. For example, when Tr = 5 minutes and Td = 100, Td
Corresponds to a display time of 5 × 100 = 500 minutes.
In step S104b, the control unit 4 monitors the state of the sensor 6 and the display control switch 8, and when the display control switch 8 is turned off or when the sensor 6 detects that the external power is turned off, step S105. And returns to step S104a otherwise. Although not shown in FIG. 2, the control unit 4 of the actual display device performs processing during the image display, in addition to the processing in step S104a and step S104b, when the setting is changed by a user operation, When the type of the input video signal changes, the power supply unit 5, the display unit 1, the video signal processing unit 2, and the driving unit 3 are controlled so that the video is displayed properly.

In step S105, the display time measuring unit 9
Then, the integrated value Td corresponding to the display time up to the present time counted in the above is written to a predetermined address of the nonvolatile memory 7.
Then, in step S106, the information about the current state of the display device is updated at a predetermined address in the nonvolatile memory 7 that is different from the integrated value Td. Thereafter, in step S107, the control unit 4 controls the power supply unit 5, the display unit 1, the video signal processing unit 2, and the drive unit 3 to perform a process of stopping the display of the video on the display unit 1. The processing from step S105 to step S107 described above is referred to as display end processing. Then, the time required for the display end processing is defined as Tend.

After the display ending process is completed, the process proceeds to step S108a, which is a standby state. When the display control switch 8 is turned on, the process returns to step S101 to perform display start processing. Until then, the standby state of step S108a is continued via step S108b.

In the display device, by performing the above-described processing, the integrated value Td corresponding to the video display time is stored in the nonvolatile memory 7. In the event of a display device failure or maintenance, the maintenance technician can read the integrated value Td from the non-volatile memory 7
It is possible to know the total display time of the display device.

When the display device is in operation, the integrated value Td may be read from the display time measuring unit 9 instead of the nonvolatile memory 7. If the control unit 4 is provided with a function of displaying a menu screen on the display unit 1 and the integrated value Td is displayed in the menu screen, the value of the integrated value Td can be confirmed on the display unit 1. . Further, a value obtained by converting the integrated value Td into an actual display time, that is, a value obtained by multiplying the integrated value Td by the measurement unit Tr may be displayed on the menu screen.

According to the configuration of the first embodiment, even when the external power is turned off, the display time can be maintained without losing the display time. Next, the operation when the external power is turned off will be described in detail. When the external power supply is cut off, the sensor 6 detects a decrease in the external power supply voltage and notifies the control unit 4 that the external power supply has been cut off. Subsequent processing is the processing after step S105 described above. That is, the integrated value Td corresponding to the display time up to the present is written into the nonvolatile memory 7 (step S105), the information indicating the current state of the display device is written (step S106), and the display is stopped (step S10).
7). Thereafter, a standby state is set (step S108).
a). In the display device, a large-capacity capacitor and a battery are built in the power supply unit 5 so that the time Tend required for the display end processing is shorter than the above-mentioned Toff. The power supply is stopped after the standby state. Therefore, the integrated value Td corresponding to the display time and the information indicating the state of the display device can be held without being lost. After that, when the supply of the external power is resumed, the control unit 4 first sets the standby state (step S10).
The process is started from 8a), and if the display control switch 8 is turned on, the process proceeds to step S101 to perform a display start process. If the display control switch 8 is turned off, the standby state is set until the display control switch 8 is turned on (step S
Continue with 108a).

The display control switch 8 does not need to be actually a physical switch. For example, the display of the display device may be turned on and off by a signal from a remote control light receiving unit connected to the control unit 4 using an infrared remote control or the like. Further, since the sensor 6 can detect the disconnection of the external power supply, a switch for connecting and disconnecting the external power supply may be connected between the sensor 6 and the external power supply, and the switch may be used as a substitute for the display control switch 8. . Alternatively, the display control switch 8 may be omitted, and the display may be turned on and off only by the detection of the external power supply interruption by the sensor 6. Specifically, the display may be turned on and off by inserting and removing a power supply plug of the display device from an outlet of an external power supply.

In the above description, the writing to the nonvolatile memory 7 is limited only to the display end processing. However, during the use of the display device, the nonvolatile memory 7 is periodically measured at the unit of measurement Tr or other predetermined intervals. 7, the integrated value Td may be written. At this time, even if a failure occurs in the control unit 4 and the display device stops operating without going through the display end processing, the display time up to that time can be stored with high accuracy. However, the non-volatile memory 7
When a device having a limited number of guaranteed rewrites is used, it is desirable to take care that the number of writes does not exceed the guaranteed number of rewrites.

As described above, according to the display device according to the first embodiment, since the display time can be recorded by the display device alone, the display device is detached from each device each time the display device is used for a plurality of purposes. Even in the case where the information is displayed, the integrated value of the display time for each application can be confirmed. Therefore, it is possible to easily determine the replacement time and the maintenance and inspection time of the display device. In addition, it is possible to determine whether the deterioration of the display function of the display device 30 is based on the life or based on other factors, and it is possible to easily analyze the failure. Therefore, high reliability of the display device and reduction in service cost can be realized.

Further, even when the external power supply is cut off, the display time measured so far can be retained without losing it, so that the integrated value of the display time up to that time can be confirmed. .

It is desirable to apply the structure of the display device according to the first embodiment to a display device using a PDP rather than a display device using a CRT or a liquid crystal. In a display device using a PDP, as the display time increases, the image quality deteriorates due to deterioration of the phosphor and the like. A similar problem also occurs in a display device using a CRT or a liquid crystal other than the PDP. However, especially when compared with a liquid crystal projector, etc., the life of the projection lamp becomes dominant in the projector, and the deterioration of the display can be improved only by replacing the lamp. Deterioration of the main body, which usually requires replacing the entire display device. Therefore, in a display device using a PDP, it is more important than a liquid crystal projector to grasp the display time in order to arrange a substitute product or the like.

Further, the PDP is still under development at the present stage, and it is highly likely that the life expectancy of the manufacturer will not be achieved. Therefore, it is necessary to feed back information on the display time and the degree of deterioration to the manufacturer. It is necessary to confirm the display time. The information becomes valuable data for improving the life of the PDP in the future. PDPs are more portable than other large-screen video devices such as liquid crystal projectors, and are likely to be used more frequently for exhibitions and events. Therefore, it is more necessary to grasp the display time by the display device alone.

Embodiment 2 In the display device according to the first embodiment, if Tr = 5 minutes, for example, the display time shorter than 5 minutes is always cut off when writing to the nonvolatile memory 7. Therefore, the integrated value Td corresponds to a value smaller than the actual display time. When the number of times the display is turned on and off increases, the difference between the actual display time and the display time corresponding to the recorded integrated value Td is integrated and increased. The display device according to the second embodiment minimizes the difference between the actual display time and the display time corresponding to the recorded integrated value Td, and improves the measurement accuracy of the display time.

FIG. 3 is a flowchart showing the operation of measuring the display time of the display device according to the second embodiment. The configuration of the display device is the same as that of the display device according to the first embodiment. 1 is as shown in the block diagram of FIG. With reference to FIG. 3, a series of operations from measuring the display time of an image on the display device to storing the measured display time in the nonvolatile memory 7 will be described. In FIG. 3, the same processes as those in the display device according to the first embodiment are denoted by the same reference numerals as those in FIG.

In step S101, as in the first embodiment, the control unit 4 writes the integrated value Td recorded at a predetermined address in the nonvolatile memory 7 into the display time measuring unit 9. Here, the integrated value Td is the same as the integrated value Td in the first embodiment. Next, in step S201,
The control unit 4 reads the flag Tds from a predetermined address in the nonvolatile memory 7 and writes the flag Tds into the display time measurement unit 9. Although the flag Tds will be described later, it is a 1-bit flag.
If ds = 0 and the integrated value Td is not increased by 1, Td
Take the value of s = 1. Next step S102 and step S
103 is the same as that of the first embodiment, the control unit 4 reads information indicating the state of the display device at the time of previous use from the nonvolatile memory 7 (step S102), and uses the read information to switch the display device to the last time. After returning to the same state as when used, display is started (step S10).
3).

Step S104, which is a process during video display
a, in S104b, as in the first embodiment, the display unit 1
While displaying the video, the display time measuring unit 9 counts up the integrated value Td for each measurement unit using the predetermined interval Tr as a measurement unit. At the same time, the control unit 4 monitors the state of the sensor 6 and the display control switch 8, and when the display control switch 8 is turned off or when the sensor 6 detects the disconnection of the external power supply, the process proceeds to step S202.

In step 202, the control unit 4 refers to the flag Tds written in the display time measurement unit 9 and
If s = 1, that is, if the integrated value Td has not been increased by 1 during the previous use, the integrated value Td is increased by 1 and the flag Tds is rewritten to 0 at the same time. When Tds = 0, that is, when the integrated value Td is increased by 1 during the previous use, the value of the integrated value Td is kept as it is, and the flag Tds is rewritten to 1. That is, in step 202, the integrated value Td is increased by 1 every other time the display is turned on and off. Next, in step S105, similarly to the first embodiment, the control unit 4
Represents the integrated value Td counted by the display time measuring unit 9,
Write to a predetermined address of the nonvolatile memory 7. Next, in step S203, the flag Tds is written to a predetermined address of the nonvolatile memory 7. Next, the processing after step S106 is the same as in the first embodiment, and a description thereof will not be repeated.
In the second embodiment, the processing from step 202 to step S107 is the display end processing, and the time required for the display end processing is Tend.

The display device according to the second embodiment is
Since the operation is performed as described above, the measurement accuracy of the display time can be improved as compared with the display device according to the first embodiment. Hereinafter, this will be described in detail.

In the display device according to the first embodiment, if the difference between the actual display time per turn of one display and the display time corresponding to the recorded integrated value Td is Ts1, 0 ≦ Ts1 <Tr. The difference Ts1 can be assumed to follow a normal distribution, except for a usage method that always turns the display on and off at a fixed time. Therefore, if the display is turned on and off N times, which is a sufficiently large number, the difference between the actual display time and the display time corresponding to the recorded integrated value Td is statistically N × (Tr / 2). Get closer. That is, when the display is switched on and off N times, the display time corresponding to the recorded integrated value Td becomes a value smaller by N × (Tr / 2) than the actual display time.

On the other hand, in the display device according to the second embodiment, in step 202, the integrated value Td is incremented by one every other time the display is turned on and off. That is, the value added to the integrated value Td per one turn of the display can be considered to be Td / 2. When converted to real time, 0.5 times of the unit of measurement Tr is added to the measured display time and recorded in the nonvolatile memory 7 each time. When the display is turned on and off N times, the display time corresponding to the recorded integrated value Td becomes a value N × (Tr / 2) larger than that of the display device according to the first embodiment. Therefore, if the display is switched on and off a sufficiently large number of times, the difference between the actual display time and the display time corresponding to the recorded integrated value Td is statistically close to zero.
That is, the display device according to the second embodiment can improve the measurement accuracy of the display time as compared with the display device according to the first embodiment.

The display device according to the second embodiment is
As compared with the display device according to the first embodiment, the amount of information to be recorded in the nonvolatile memory 7 is increased by one bit by the recording of the flag Tds. To compare the required capacity of the nonvolatile memory 7 with the same capacity, the first embodiment
In the display device according to the above, the case where Tr = 2.5 minutes is considered. If Tr = 2.5 minutes, the unit of measurement is halved as compared with the case of Tr = 5 minutes, so that the maximum value of the integrated value Td corresponding to the measured display time is doubled, The number of bits required to store the integrated value Td increases by one. As described above, the display device according to the first embodiment in which Tr = 2.5 minutes has the same required capacity of the nonvolatile memory 7 as the display device according to the second embodiment in which Tr = 5 minutes.

If Tr = 2.5 minutes, the display time of less than 2.5 minutes is cut off at the end of the display. Compared to when Tr = 5 minutes, the actual display time
The error with the display time corresponding to the recorded integrated value Td is halved, but the error is integrated every time the display is turned on and off, and the display is performed N times, which is a sufficiently large number. The difference between the actual display time when turning on and off and the display time corresponding to the recorded integrated value Td is:
Statistically approaches N × 1.25 minutes. As described above, in the display device according to the second embodiment, regardless of the value of the measurement unit Tr, the actual display time and the recorded integrated value Td
Is statistically close to 0, so it can be said that the display device according to the second embodiment has better measurement accuracy of the display time in the long term. If Tr = 2.5 minutes, the process of increasing the integrated value Td is required once every 2.5 minutes, and the load on the control unit 4 is increased.

In the above description, step 202
Is performed at the beginning of the display end process, but is not limited to this, and may be performed from the start of display to the time when the integrated value Td and the flag Tds are stored in the nonvolatile memory 7. For example, the display start process is performed. You may go to the beginning.

As described above, according to the display device according to the second embodiment, if the number of times the display of the display device is turned on and off increases, the difference between the display time corresponding to the recorded integrated value Td and the actual display time is obtained. However, since the value statistically approaches 0, the display time measurement accuracy can be improved as compared with the display device according to the first embodiment.

Further, the display time measurement accuracy can be improved as compared with a display device which improves the display time measurement accuracy by reducing the measurement unit without increasing the memory capacity of the nonvolatile memory 7.

In step 202, the integrated value Td is incremented by one every other time the display is turned on and off. However, the effect of the present invention is not limited to this, and the integrated value Td is calculated with a probability of 1/2. What is necessary is just to increase the value Td. Specifically, when the display is turned on and off N times, (N /
2) It is sufficient that the integrated value Td is increased twice. Even if the process is such that the integrated value Td is increased twice consecutively and thereafter the integrated value Td is not increased continuously, the same applies. Produces an effect.

[0057]

According to the display time measuring method according to the first aspect of the present invention, even when there is no external power supply, the display time measured so far can be maintained without losing it. Therefore, the measured display time can be confirmed.

According to the display time measuring method of the present invention, the display time measured this time is added to the display time measured last time and stored, so that the integrated value of the measured display time is calculated. You can check.

According to the display time measuring method of the present invention, the difference between the recorded display time and the actual display time is statistically close to zero. Time measurement accuracy can be improved.

According to the display device of the present invention, since the display time of the image can be measured and stored by the display device alone, a maintenance person or the like can check the display time. Can be.
Therefore, it is possible to easily determine the replacement time and the maintenance and inspection time of the display device.

Further, it is possible to determine whether the deterioration of the display function of the display device is based on the life or other factors, and it is possible to easily perform the failure analysis. Therefore, high reliability of the display device and reduction in service cost can be realized.

Further, according to the display device of the present invention, even if the image is displayed intermittently a plurality of times, the integrated value of the image display time for each time can be stored. Therefore, the display time of a display device that does not always display an image can be confirmed.

According to the display device of the present invention, since the display time of the video is measured by the counter which counts at a predetermined interval, the display device stores the display time as it is. It is possible to reduce the capacity of the memory for storing the measurement result. As a result, the cost of the display device can be reduced.

According to the display device of the present invention, since the measured display time can be recorded in the nonvolatile memory, the display device may be detached from the device body. Even so, it is possible to check the integrated value of the previous display time.

According to the display device of the ninth aspect of the present invention, the measured display time can be stored in the non-volatile memory even when power is not supplied to the device. Even if the power supply to the device is suddenly stopped due to, for example, the measured display time can be confirmed.

According to the display device of the present invention, a PDP is used as a display unit of the display device. The PDP is still developing at the present stage, and it is highly likely that the life expectancy of the manufacturer will not be achieved. Therefore, it is necessary to feed back information on the display time and the degree of deterioration to the manufacturer. Therefore, the effects of the inventions according to claims 5 to 7 are more important than a display device using a stable cathode ray tube or a liquid crystal as a display unit as a product.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a display device according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart illustrating an operation of measuring a display time of the display device according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of measuring a display time of a display device according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a conventional information processing apparatus having a life monitoring function of a display device.

[Explanation of symbols]

Reference Signs List 1 display unit, 2 video signal processing unit, 3 drive unit, 4 control unit, 5 power supply unit, 6 sensors, 7 nonvolatile memory, 8
Display control switch, 9 Display time measurement unit.

Continuation of the front page (72) Inventor Akihiro Kaminen 1 Baba Zujo, Nagaokakyo-shi, Kyoto Mitsubishi Electric Microcomputer Software Co., Ltd. F-term (reference) 5C080 AA05 BB05 DD14 DD27 JJ02 JJ07 5C082 CB01 EA20 MM05 MM06 MM07 MM09

Claims (10)

[Claims] (A) measuring a display time during which an image is displayed to obtain a measured display time; (b) storing the measured display time; and (c) no external power supply. And a step of maintaining a voltage necessary for performing the step (b). (D) a step of, after the display of the image is once terminated, measuring a display time for displaying a new image next to obtain a new measured display time; A) adding the measured display time stored in the step (d) to the measured display time measured in the step (d); and (f) storing the value obtained by the addition as the measured display time. 2. The display time measuring method according to claim 1, further comprising the step of: 3. In the steps (a) and (d), the measured display time is obtained by using the display time as a unit of a predetermined interval. 2
The display time measuring method according to claim 2, wherein one of the units is also added at the probability of: 4. The steps (d) to (f) are repeated as a set, and in the step (e), one of the executions is performed.
The display time measuring method according to claim 3, wherein one of the units is added every other time. 5. A display device integrally comprising a display unit for displaying an image, a display time measuring unit for measuring a display time of the image on the display unit, and a memory for storing a measurement result of the display time measuring unit. 6. The display device according to claim 5, wherein the display unit performs video display intermittently a plurality of times, and the memory stores an integrated value of the measurement results for each video display. 7. The display time measuring section has a counter whose count value changes in one direction at predetermined intervals of the display time, and the measurement result is the count value. Item 7. A display device according to item 6. 8. The display device according to claim 5, wherein said memory is non-volatile. 9. The display device according to claim 8, further comprising a power supply unit for maintaining a voltage required for the memory to store the measured display time when power is not supplied to the device. 10. The display device according to claim 5, wherein said display unit is a plasma display panel.