JP2008122695A - Liquid crystal display and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve the productivity of liquid crystal displays by reducing the time required for their aging tests as much as possible. <P>SOLUTION: The method checks whether the aging mode-on has been performed right before the aging test (S1) and temporarily adjust the back light supply power to the maximum allowable power (power higher than the standard supply voltage) after it checks until the predetermined time ts passes (S2-S7). When the inner temperature rises higher than the upper limit during this period, it turns off the power to the electric components to enter the standby mode (S9). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device having a backlight for illuminating a liquid crystal panel from the back side thereof, and a control method thereof.

A liquid crystal display device employed as a monitor for a so-called liquid crystal television or an electronic computer serves as a heat source for a liquid crystal panel, a backlight (illuminating means) for illuminating the liquid crystal panel from the back side, a driving circuit for the liquid crystal panel, etc. It has many electrical components that generate heat.
Here, the general liquid crystal display device includes a brightness sensor disposed on the front side of the liquid crystal panel, and power supplied to the backlight (light emission intensity) is adjusted according to the detected brightness. The That is, when the brightness of the usage environment of the liquid crystal display device is brighter than a reference level, power higher than the reference power is supplied to the backlight, and the brightness of the usage environment of the liquid crystal display device is increased. When it is darker than the reference level, power lower than the reference power is supplied to the backlight. Thereby, the brightness of the liquid crystal panel is adjusted to a brightness that is easy for the user to see.
Patent Document 1 discloses a liquid crystal display device that includes a brightness sensor disposed on the back side of the liquid crystal panel and adjusts the power supplied to the backlight (light emission intensity) according to the detected brightness. It is shown.

By the way, Patent Document 2 shows that, in the manufacture of a liquid crystal television (an example of the liquid crystal display device), an aging test is performed on a liquid crystal television assembled as a product before shipment. Thereby, it is possible to increase the productivity of the liquid crystal display device than to perform the aging test for each part before assembly. In the aging test, the liquid crystal display device includes almost all of the liquid crystal panel and its drive circuit. In a state where power is supplied to the electrical components (hereinafter referred to as “use state”), the electrical components are placed in a thermostatic chamber maintained at a predetermined test temperature for a predetermined evaluation time and placed in such an installation environment. Even if this is done, a confirmation test is performed to confirm that it operates normally. Here, the test temperature is set to, for example, the maximum temperature of the use environment in which the normal operation of the liquid crystal display device is guaranteed or a temperature slightly exceeding the maximum temperature.
In addition, the liquid crystal display device includes a large number of electrical components that serve as heat sources (heat generation) such as a backlight (illuminating means) that illuminates the liquid crystal panel from the back side thereof, and a drive circuit of the liquid crystal panel. For a while after that, the internal temperature of the liquid crystal display device rises due to the heat generated by the electrical components. Then, the internal temperature eventually becomes substantially constant in a state where it reaches a stable temperature (hereinafter referred to as a steady temperature).
In the aging test, after the internal temperature of the liquid crystal display device becomes the steady temperature, it is important that the liquid crystal display device is continuously placed in the environment of the test temperature for the evaluation time. Therefore, in the actual aging test, the liquid crystal display device includes the evaluation time required for the test and a predetermined warm-up time in the thermostatic chamber whose internal temperature is maintained at the test temperature. It is set for the added time.
Here, the warm-up time is a time until the internal temperature reaches the steady temperature after the liquid crystal display device is in the use state, and is measured in advance by an experiment using a sample machine or the like. It is.
Japanese Patent Laid-Open No. 4-314025 JP 2006-153992 A

However, the warm-up time in the aging test is long, which hinders further improvement in the productivity of the liquid crystal display device. In particular, the larger the liquid crystal display device, the larger the heat capacity thereof, and thus the longer the warm-up time, and the warm-up time becomes a major impediment to improving the productivity of the liquid crystal display device.
For example, in the liquid crystal display device in which the size of the liquid crystal panel exceeds 50 inches, the warm-up time may be 1 hour or longer.
Accordingly, the present invention has been made in view of the above circumstances, and its object is to reduce the time required for the aging test of the liquid crystal display device as much as possible, and as a result, it can contribute to further productivity improvement. And providing a control method thereof.

In order to achieve the above object, the present invention is a liquid crystal display device comprising a backlight for illuminating a liquid crystal panel from the back side, and further comprising components shown in the following (1) and (2).
(1) Trigger information detecting means for detecting the input of trigger information inputted through a predetermined input means when an aging test of the liquid crystal display device is performed.
(2) When input of the trigger information is detected by the trigger information detection means, the supply power to the backlight is set to be higher than the standard supply power adjusted in a state before the input of the trigger information is detected. Backlight power adjustment means during aging to temporarily adjust to high power.
Here, as the processing executed by the aging backlight power adjusting means, the processing shown in either of the following (3) or (4) can be considered.
(3) A process of adjusting power higher than the standard supply power until a predetermined time elapses after the trigger information is detected.
(4) In the case where the liquid crystal display device includes an internal temperature detecting means for detecting an internal temperature of the liquid crystal display device, the liquid crystal display device has a temperature that is equal to or higher than a target temperature predetermined by the internal temperature detecting means after the input of the trigger information is detected. A process of adjusting the power to be higher than the standard supply power until temperature is detected.
The liquid crystal display device according to the present invention temporarily increases the power supplied to the backlight, which is the main heat source in the liquid crystal display device, when the trigger information is input when the aging test is performed. Temporarily increase the amount of heat generation. As a result, the warm-up time in the aging test (the time from when the liquid crystal display device enters the use state until the internal temperature reaches the steady temperature) is shortened as compared with the prior art. In particular, when the size of the liquid crystal display device is large, the amount of heat generated by the backlight is large, and the effect of greatly shortening the warm-up time can be obtained.

Further, in the case where the liquid crystal display device according to the present invention includes the internal temperature detection means, the power to the backlight is further detected when a temperature equal to or higher than a predetermined upper limit temperature is detected by the internal temperature detection means. It is conceivable to have a power supply emergency stop means for stopping the supply.
Thereby, it is possible to prevent the parts from being excessively heated due to the processing of the backlight power adjusting means during aging, and the parts from being damaged.
In addition, when the liquid crystal display device includes a motor that drives a ventilation fan that discharges the internal air to the outside, the power supplied to the backlight by the backlight power adjustment unit during aging is higher than the standard supply power The power supplied to the motor that drives the ventilation fan while being adjusted to power is adjusted to a power higher than the standard power adjusted in a state before the input of the trigger information is detected, and the backlight at the time of aging It is conceivable to further include an aging ventilation fan power adjustment means for stopping the supply power to the motor that drives the ventilation fan from the time when the supply power to the backlight is returned to the standard supply power by the power adjustment means.
Thus, the warm-up time can be further shortened by temporarily increasing the power supplied to the ventilation fan, which consumes relatively large power in the liquid crystal display device. In addition, by stopping the ventilation fan after the warm-up is completed, it is possible to avoid the temperature inside the apparatus from returning and dropping due to the inflow of outside air.
In addition, the present invention may be a method for controlling the liquid crystal display device that executes the following steps (1) and (2).
(1) A trigger information detection step of detecting input of trigger information input through predetermined input means when an aging test of the liquid crystal display device is performed by predetermined detection means.
(2) When input of the trigger information is detected by the trigger information detection step, the power supplied to the backlight is adjusted in a state before the input of the trigger information is detected by a predetermined power adjusting unit. A backlight power adjustment process during aging that temporarily adjusts to a higher power than the standard supplied power.
In addition, the effect by performing such a control method of a liquid crystal display device is the same as the effect in the liquid crystal display device which concerns on this invention.

  According to the present invention, the warm-up time in the aging test (the time from when the liquid crystal display device is in the use state until the internal temperature reaches the steady temperature) is shortened as compared with the prior art. The productivity of the liquid crystal display device can be further increased. In particular, when the size of the liquid crystal display device is large, the effect of greatly shortening the warm-up time can be obtained, and a higher productivity improvement effect can be obtained.

Embodiments of the present invention will be described below with reference to the accompanying drawings for understanding of the present invention. In addition, the following embodiment is an example which actualized this invention, Comprising: It is not the thing of the character which limits the technical scope of this invention.
1 is a block diagram showing a schematic configuration of the liquid crystal display device X according to the embodiment of the present invention, FIG. 2 is a flowchart showing a procedure of power adjustment processing in the aging mode of the liquid crystal display device X, and FIG. 3 is a liquid crystal display. 6 is a trend graph of internal temperature in the device X and a time chart of power supplied to a backlight and the like.

First, the configuration of the liquid crystal display device X according to the embodiment of the present invention will be described using the block diagram shown in FIG. The liquid crystal display device X shown in FIG. 1 is a television receiver that displays on the liquid crystal panel 21 an image based on a television broadcast signal received by an antenna or the like.
The liquid crystal display device X has a fluorescent tube 12 (indicated as CFL in the drawing) that illuminates the back surface of the liquid crystal panel 21 with substantially white light, and a red light that similarly illuminates the back surface of the liquid crystal panel 21 with red light. A hybrid backlight having each of the light emitting LEDs 13 is provided.
In the present embodiment, a television receiver is shown as an example of the configuration of the liquid crystal display device X. However, the application target of the present invention is not limited to this, and for example, a liquid crystal display device as a computer monitor, a liquid crystal panel, Any other liquid crystal display device may be used as long as it includes a backlight. Further, the backlight may be of a type that is not illuminated by the hybrid type but only by the fluorescent tube 12 or only by RGB three-color (synthesized white) LEDs.
As shown in FIG. 1, the liquid crystal display device X includes a plurality of tuners 1a, 1b, 1c, an external input unit 2, a video switching circuit 3, a video processing circuit 4, a liquid crystal panel driving circuit 5, a timer circuit 6, and a remote controller 7. , Control circuit 8, remote control interface (I / F) circuit 9, liquid crystal panel 21, fluorescent tube 12 and LED 13 constituting the backlight, inverter circuit 14, LED drive circuit 15, color sensor 16, brightness sensor 17, temperature sensor 18, a voice switching circuit 10, a voice processing circuit 11, an amplifier 22, a speaker 23, and the like.

Each of the tuners 1a, 1b, and 1c receives a terrestrial broadcast signal, a BS satellite broadcast signal, and a CATV broadcast signal, and extracts a broadcast channel signal indicated by the control circuit 8 from the input broadcast signals. (Selection), and the video signal and the audio signal are extracted by detecting the extracted signal, and the video signal and the audio signal are transmitted to the video switching circuit 3 and the audio switching circuit 10, respectively.
The external input unit 2 receives an external input video signal and an external input audio signal such as a composite or separate video signal and audio signal from the outside, and inputs them to the video switching circuit 3 and the audio switching circuit. 10 is an interface for transmission to each.
The video switching circuit 3 inputs video signals from each of the tuners 1a, 1b, and 1c and a video signal from the external input unit 2, and selects any one of the video signals from the control circuit. 8 is selected and output in accordance with the instruction from FIG.

The video processing circuit 4 performs various signal processing on the video signal output from the video switching circuit 3. For example, separation of horizontal and vertical synchronization signals from the video signal, generation of a clock signal phase-synchronized with the synchronization signal, separation of luminance and color signals from the video signal, predetermined image quality improvement processing, etc. A signal is output to the liquid crystal panel drive circuit 5.
The liquid crystal panel drive circuit 5 is a circuit that drives the liquid crystal panel 21 based on the video signal transmitted from the video processing circuit 4 and displays the video corresponding to the video signal on the liquid crystal panel 21.
The control circuit 8 is an MPU 8a that is an arithmetic means, a ROM 8b (EPROM) that is a storage means in which a control program executed by the MPU 8a is stored in advance, and a setting that is read / written (referenced or written) in processing executed by the MPU 8a. An EEPROM 8c or the like for storing information is provided, and the entire liquid crystal display device X is controlled.
The timer circuit 6 measures time and time specified by the control circuit 8. The time measurement result of the timer circuit 6 is transmitted to the control circuit 8.
The remote control interface circuit 9 obtains operation input information for the remote control 7 by wireless transmission such as infrared transmission from the remote control 7 (remote operation device) for operation of the liquid crystal display device X, and the operation input information is controlled by the control. This is output to the circuit 8.

The audio switching circuit 10 receives an audio signal from each of the tuners 1a, 1b, and 1c and an audio signal from the external input unit 2, and controls any one of the audio signals as the control signal. According to an instruction from the circuit 8, the sound is output to the sound processing circuit 11.
The audio processing circuit 11 performs various signal processing on the audio signal output from the audio switching circuit 10 in accordance with instructions from the control circuit 8. For example, equalization processing, surround processing, or the like that matches the characteristics of the speaker 23 is performed.
The amplifier 22 performs a process of amplifying or attenuating the audio signal processed by the audio processing circuit 11 in accordance with an instruction from the control circuit 8 and outputs the amplified signal to the speaker 23.
The liquid crystal panel 21 displays video based on the video signal output from the video processing circuit 4.
The brightness sensor 17 is a sensor that detects the brightness of the front side of the liquid crystal panel 21 (the brightness of the installation environment of the liquid crystal display device X), and the color sensor 16 is the back side of the liquid crystal panel 21. Is a sensor for detecting the color distribution of light (distribution of R, G, B). These sensors are used for brightness (output) control of the fluorescent tube 12 and the LED 13 as described later.

The fluorescent tube 12 constituting the backlight of the liquid crystal panel 21 emits substantially white light which is a combined light of red, green and blue wavelengths, and is configured by arranging a plurality of fluorescent tubes. Has been. Similarly, the LED 13 that constitutes the backlight is a red LED that emits light having a red wavelength, and a plurality of LEDs 13 are arranged between the plurality of fluorescent tubes 12.
The fluorescent tube 12 is driven by the inverter circuit 14 (indicated as an INV circuit in the figure), and the inverter circuit 14 supplies power supplied to the fluorescent tube 12 in accordance with a control command output from the control circuit 8. Adjust.
Specifically, a rectangular wave pulse signal is output from the control circuit 8 to the inverter circuit 14, and a pulsed driving voltage synchronized with the pulse signal is supplied to the fluorescent tube 12. Then, by adjusting the duty ratio of the pulse signal output from the control circuit 8 to the inverter circuit 14, the brightness of the fluorescent tube 12 is adjusted (i.e., supplied) by PWM (Pulse Width Modulation) dimming. Power adjustment). As a result, the fluorescent tube 12 is turned on / off and the brightness is adjusted.
On the other hand, the LED 13 (red LED) is driven by the LED drive circuit 15, and the LED drive circuit 15 adjusts the supply power (supply current) to the LED 13 in accordance with a control command output from the control circuit 8. As a result, the brightness of the LED 13 is adjusted by the current dimming method. As a result, the LED 13 is turned on / off and the brightness is adjusted.

The temperature sensor 18 is a sensor that detects the internal temperature of the liquid crystal display device X (an example of the internal temperature detection means), and the detected temperature is input to the control circuit 8. The temperature sensor 18 is, for example, a thermistor or the like, and is disposed in a housing or the like provided on the back side of the liquid crystal panel 21.
The display brightness of each color (RGB) on the liquid crystal panel 21 is determined by the level of a voltage (hereinafter referred to as a gradation voltage) of a drive signal output from the liquid crystal panel drive circuit 5 to the liquid crystal panel 21. Also affected by temperature.
Therefore, the control circuit 8 corrects the gradation voltage output from the liquid crystal panel drive circuit 5 by outputting a correction signal to the liquid crystal panel drive circuit 5 based on the temperature detected by the temperature sensor 18. . Thereby, even if environmental temperature changes, the image quality of the display image by the said liquid crystal panel 21 is maintained favorable.
Further, the liquid crystal panel driving circuit 5 directly designates the gradation voltage level from the control circuit 8, so that the gradation voltage is set regardless of the content of the video signal transmitted from the video processing circuit 4. A function to set the specified voltage is provided. As a result, the liquid crystal panel drive circuit 5 can adjust the power supplied to the liquid crystal panel 21 in accordance with the level of the gradation voltage specified by the control circuit.

By the way, after the liquid crystal display device X is assembled as a product, an aging test is performed before shipment.
In the aging test, the liquid crystal display device X includes all the electrical components shown in FIG. 1 (the tuners 1a to 1c, the video switching circuit 3, the video processing circuit 4, the liquid crystal panel drive circuit 5, the backlight). And the inverter circuit 14 and the LED driving circuit 15, the liquid crystal panel 21, the sound switching circuit 10, the sound processing circuit 11, and the amplifier 22) that drive the power supply circuit are used. After the evaluation time (for example, 24 hours) or more is placed in a thermostat maintained at the test temperature (for example, 40 ° C.), the confirmation test is performed.
Here, in the liquid crystal display device X, when the aging test is performed, an aging mode ON operation, which is a predetermined special operation (operation not disclosed to general users), is performed on the remote controller 7 by an inspector. . As the special operation, for example, an operation of inputting a predetermined personal identification number with a numeric key in the remote controller 7 within a predetermined time (several seconds) or a plurality of predetermined operation keys in the remote controller 7 are simultaneously pressed. Operation is considered.
When the control circuit 8 detects that the aging mode ON operation has been performed, the control circuit 8 executes an aging mode power adjustment process described below.
The power adjustment process in the aging mode is a process for temporarily increasing power supplied to the backlight (here, the fluorescent tube 12 and the LED 13) and the liquid crystal panel 21. The liquid crystal display device X is placed in the thermostatic chamber during the aging mode power adjustment process.
In the liquid crystal display device X, an operation state from when the aging mode ON operation to the remote controller 7 is detected until the power adjustment processing in the aging mode is finished is called an aging mode, and other operation states are a normal mode. That's it.
The method for adjusting the power supplied to the backlight and the liquid crystal panel 21 in the normal mode is as described above.
That is, the control circuit 8 adjusts the power supplied to the fluorescent tube 12 based on the detection result of the brightness sensor 17 and further adjusts the power supplied to the LED 13 based on the detection result of the color sensor 16. .
The liquid crystal panel driving circuit 5 adjusts basic supply power (that is, the gradation voltage) to the liquid crystal panel 21 based on the video signal transmitted from the video processing circuit 4, and the control circuit 8 corrects the power supplied to the liquid crystal panel 21 (that is, the gradation voltage) based on the temperature detected by the temperature sensor 18.

Next, the procedure of the aging mode power adjustment process realized by the MPU 8a of the control circuit 8 executing a predetermined control program will be described with reference to the flowchart shown in FIG. Note that the processing shown in FIG. 2 is started when the liquid crystal display device X is activated (powered on) and enters the normal mode by a power-on operation or the like with respect to the remote controller 7. Further, S1, S2,... Shown below represent identification codes of processing procedures (steps).
[Step S1]
First, the control circuit 8 monitors whether the aging mode ON operation has been performed on the remote controller 7 in the normal mode (S1).
In step S1, the control circuit 8 determines in advance through the remote control interface circuit 9 (an example of the input means) whether or not the aging mode ON operation performed immediately before the aging test is started. It is determined by detecting whether or not an aging start command (an example of the trigger information) is input (an example of the trigger information detection means).
When the control circuit 8 detects the input of the aging start command in the process of step S1, the control circuit 8 executes the power adjustment process in the aging mode (S2 to S10) using it as a trigger.

[Steps S2 to S4]
When the input of the aging start command is detected in the process of step S1, the control circuit 8 adjusts the power supplied to the backlight so as to be a predetermined allowable maximum power (S2). Here, the allowable maximum power is a maximum supply power allowed for the backlight, and is based on a standard supply power adjusted in the normal mode (a state before the input of the aging start command is detected). Is high power (for example, about 1.2 times). The state in which the allowable maximum power is supplied is a temporary state until the process of step S7 described later is executed.
Specifically, the control circuit 8 outputs predetermined control commands to the inverter circuit 14, the LED drive circuit 15, and the liquid crystal panel drive circuit 5, respectively, thereby the fluorescent tube 12, the LED 13, and the liquid crystal. Adjustment is made so that the power supplied to each panel 21 is higher than that in the normal mode (the allowable maximum power).
Further, the control circuit 8 sets a predetermined time ts in the timer circuit 6 to start time measurement by the timer circuit 6 (S3).
Further, the control circuit 8 starts a process of notifying that the aging power adjustment process is being performed (that the aging mode is in effect) (S4).
For example, the control circuit 8 turns on an LED lamp (not shown) or controls the liquid crystal panel drive circuit 5 to display a message to the effect that the liquid crystal panel 21 is in the aging mode.

[Steps S5 to S8]
Next, the control circuit 8 monitors whether or not the detected temperature (internal temperature) of the temperature sensor 18 is equal to or higher than a predetermined upper limit temperature (for example, 60 ° C.) (S5), and the timer Monitoring (S6) of whether the time measured by the circuit 6 has passed the time ts is continuously executed.
Then, when the control circuit 8 detects that the time measured by the timer circuit 6 has passed the time ts, the control circuit 8 ends the interruption process of adjusting the supply power to the maximum power for the backlight. Then, the process returns to the adjustment process of the supplied power in the original normal mode (S7).
That is, the control circuit 8 temporarily supplies the maximum power supplied to the backlight and the liquid crystal panel 21 until a predetermined time ts elapses after the input of the aging start command is detected (S1). The power is adjusted to an allowable power (an example of power higher than the standard supply power) (an example of the backlight power adjusting means during aging).
Further, the control circuit 8 terminates the notification indicating that the aging mode is started in Step S4 (S8), and then returns the process to Step S1 described above.

[Steps S9 to S10]
On the other hand, the control circuit 8 determines that the detected temperature (internal temperature) of the temperature sensor 18 is equal to or higher than the upper limit temperature before the time measured by the timer circuit 6 has passed the time ts in step S5. Is detected, the switch circuit (not shown) is controlled to urgently stop the power supply to the backlight (energization OFF) and shift the liquid crystal display device X to the standby state (an example of the power supply emergency stop means) ).
As a result, the aging mode power adjustment process prevents the temperature of each component from becoming excessively high and damaging the component.
Further, the control circuit 8 blinks an LED lamp (not shown) (S10) and ends the control process. The LED lamp blinks to notify that the power supply to the backlight has been stopped urgently.

FIG. 3 shows a trend graph of a temperature detected by the temperature sensor 18 (hereinafter referred to as an internal temperature Tx) in the liquid crystal display device X, and a time chart of the power supplied to the backlight and the liquid crystal panel 21.
In FIG. 3, a graph g1 and a graph g2 represent trend graphs of the internal temperature Tx when the control circuit 8 does not execute the power adjustment process during the aging mode and when it does.
As described above, the control circuit 8 supplies the backlight, which is a main heat source in the liquid crystal display device X, and the liquid crystal panel 21 when the aging start command is input when the aging test is performed. The electric power is temporarily increased (increased from P0 to P1 in FIG. 3) until the time ts elapses (from the “aging mode ON” time point to the “aging mode OFF” time point in FIG. 3).
As a result, in the aging test in which the liquid crystal display device X is placed in a constant temperature bath, the warm-up time from when the liquid crystal display device X is in the use state until the internal temperature Tx reaches the steady temperature Ts. However, in the case where the aging mode power adjustment process is not executed, in the case where the same process is executed with respect to g1, g2 is shortened by Δta shown in FIG.

By the way, in the embodiment described above, an example in which the allowable maximum power is supplied to the backlight and the liquid crystal panel 21 until the time ts elapses after the input of the aging start command is detected. However, other embodiments are possible.
For example, until the control circuit 8 detects the input of the aging start command (S1) and detects a temperature equal to or higher than a predetermined temperature by the temperature sensor 18, it controls the backlight and the liquid crystal panel 21. It is also conceivable to adjust the supply power to the maximum allowable power (an example of power higher than the standard supply power) (an example of the backlight power adjustment means during aging).
Specifically, in step S6 shown in FIG. 2, the control circuit 8 determines whether or not the temperature detected by the temperature sensor 18 is equal to or higher than a predetermined target temperature. If not, the process may be shifted to step S5. Here, the target temperature is, for example, the steady temperature Ts or a temperature lower by several degrees Celsius.
Such an embodiment is also an example of an embodiment of the present invention.

In the embodiment, the liquid crystal display device X that temporarily increases the power supplied to the backlight during the aging mode has been described. However, there are other targets for changing the power supplied together with the liquid crystal display device X.
For example, the liquid crystal display device X includes a motor that drives a ventilation fan (a fan that exhausts the internal air of the liquid crystal display device X to the outside) not shown in FIG. 1 and a circuit that adjusts the power supplied to the motor. The control circuit 8 may change the power supplied to the ventilation fan.
In this case, while the control circuit 8 is adjusting the power supplied to the backlight to a power higher than the standard power, the power supplied to the motor that drives the ventilation fan is input to the aging start command. The power supplied to the motor that drives the ventilation fan is adjusted from the time when the power supplied to the backlight is returned to the standard power after the power is adjusted to be higher than the standard power that is adjusted in the state before being detected. Stop (an example of the aging ventilation fan power adjusting means).
Thus, the warm-up time can be further shortened by temporarily increasing the power supplied to the ventilation fan, which consumes relatively large power. In addition, by stopping the ventilation fan after the warm-up is completed, it is possible to avoid the temperature inside the apparatus from returning and dropping due to the inflow of outside air.

  The present invention can be used for a television receiver.

1 is a block diagram illustrating a schematic configuration of a liquid crystal display device X according to an embodiment of the present invention. 6 is a flowchart showing a procedure of power adjustment processing during aging mode of the liquid crystal display device X. The trend graph of internal temperature in the liquid crystal display device X, and the time chart of the electric power supplied to a backlight.

Explanation of symbols

X ... Liquid crystal display devices 1a, 1b, 1c ... Tuner 2 ... External input unit 3 ... Video switching circuit 4 ... Video processing circuit 5 ... Liquid crystal panel drive circuit 6 ... Timer circuit 7 ... Remote control 8 ... Control circuit 9 ... Remote control interface circuit 10 ... Audio switching circuit 11 ... Audio processing circuit 12 ... Fluorescent tube (backlight)
13 ... LED (Backlight)
DESCRIPTION OF SYMBOLS 14 ... Inverter circuit 15 ... LED drive circuit 16 ... Color sensor 17 ... Brightness sensor 18 ... Temperature sensor 21 ... Liquid crystal panel S1, S2, ... Step (processing procedure)

Claims (6)

A liquid crystal display device having a backlight for illuminating the liquid crystal panel from the back side,
Trigger information detection means for detecting the input of trigger information input through a predetermined input means when the aging test of the liquid crystal display device is performed;
When input of the trigger information is detected by the trigger information detection means, the supply power to the backlight is temporarily set to be higher than the standard supply power adjusted in the state before the input of the trigger information is detected. Backlight power adjustment means for aging to adjust to high power,
A liquid crystal display device comprising:   2. The liquid crystal display according to claim 1, wherein the backlight power adjusting means at the time of aging is adjusted to a power higher than the standard supply power until a predetermined time elapses after the input of the trigger information is detected. apparatus. Comprising an internal temperature detecting means for detecting the internal temperature of the liquid crystal display device;
The aging backlight power adjusting means adjusts to a power higher than the standard supply power until a temperature equal to or higher than a predetermined target temperature is detected by the internal temperature detecting means after the input of the trigger information is detected. The liquid crystal display device according to claim 1. Internal temperature detection means for detecting the internal temperature of the liquid crystal display device;
Power supply emergency stop means for stopping power supply to the backlight when a temperature equal to or higher than a predetermined upper limit temperature is detected by the internal temperature detection means;
The liquid crystal display device according to claim 1, comprising: A motor that drives a ventilation fan that exhausts the air inside the liquid crystal display device to the outside;
Input of the trigger information is detected for the power supplied to the motor that drives the ventilation fan while the power supplied to the backlight is adjusted to be higher than the standard power supplied by the backlight power adjusting means during aging. The motor which drives the ventilation fan from the time when the power supplied to the backlight is returned to the standard supply power by the backlight power adjustment means during the aging is adjusted to a power higher than the standard power adjusted in the state before A ventilation fan power adjustment means for aging to stop the power supply to
The liquid crystal display device according to claim 1, comprising: A method for controlling a liquid crystal display device having a backlight for illuminating a liquid crystal panel from the back side,
A trigger information detection step of detecting input of trigger information input through predetermined input means when an aging test of the liquid crystal display device is performed, by predetermined detection means;
When input of the trigger information is detected by the trigger information detection step, the power supplied to the specific electrical component is adjusted by a predetermined power adjusting unit in a state before the input of the trigger information is detected. A backlight power adjustment process during aging that temporarily adjusts to a higher power than the standard supply power.
A method for controlling a liquid crystal display device, comprising:

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