JP2001296835A - Control method for display device and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device and the control method of the display device for controlling the power consumption of the display device so as to become small in the display device whose display capacity is large, whose screen is made large in size, which is of high definition and whose power consumption is large in order to make a picture to be high luminance, to make its screen large in size and to make its panel to be multiple color display. SOLUTION: In the control method of the display device in which sustaining discharge pulses are used, a detected signal based on a driving voltage is subjected to an analog-to-digital conversion to be supplied to an arithmetic processing circuit part and the control signal based on the calculated result of the circuit part is supplied to a luminance control circuit controlling the frequency of the sustaining discharge pulses as binary data. The calculation in the circuit part includes the performing of the comparison calculation between the value of the converted signal and a prescribed reference value and the luminance control circuit controls the frequency of the sustaining discharge pulses so that the value of the power consumption of the display device becomes equal to or smaller than a prescribed fixed value based on the supplied binary data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and a control method for the display device, and more particularly to a control device for controlling power consumption of a display device using a sustain discharge pulse and a control method therefor. It is.

[0002]

2. Description of the Related Art In a conventional display device, a method of automatically controlling power consumption is known, and a function of automatically controlling power consumption in such a display device is generally an APC. It is called a function. In the related art of the APC function, since the display ratio and the power consumption are almost proportional, for example, the input display data is digitally counted, and when the input display data exceeds a certain data number, the brightness control is performed in accordance with the data number. In this method, a multi-color display device performs gradation display, so that it is difficult to calculate the conversion between input data and power consumption. As another method, there is a method in which power consumption is detected from an average current of a high-voltage power supply for driving a device, converted into a voltage, compared with a reference voltage by an OP amplifier or the like, and the frequency of the sustaining pulse is controlled. In this case, according to the conventional driving method, control is performed to output or not output one discharge sustaining pulse during the horizontal synchronization period. Therefore, when an external brightness control is input, the discharge maintaining pulse of the APC function is output. Since the frequency of the pulse and the frequency of the sustaining pulse for luminance adjustment must be compatible, it is necessary to properly set the frequency of the intermittent period of the sustaining pulse.
Further, depending on the selected frequency, a display abnormal phenomenon such as flicker may occur.

FIG. 10 shows a configuration of a conventional automatic power consumption control (APC control) and a brightness control device in the APC function. In FIG. 10, reference numeral 1 denotes a circuit for detecting a power supply current value inside the unit and converting it into a voltage level, and 2 denotes a voltage which is adjusted by current detection of the circuit 1 during a fixed period (APC period) as shown in FIG. An APC pulse generator 3 for changing the pulse width of the luminance is a luminance volume for the user to set, and 4 is a constant period (BC) as shown in FIG.
BC pulse generator that can change the pulse width during
Represents the APC and BC pulses

(Equation 1) (The signal defining the scanning period of one line), the logic is fixed, the logical product is performed, and the next luminance selection ROM
6 is a circuit for designating an upper address to the ROM 6, and a ROM 6 stores a luminance waveform corresponding to the address designation from the circuit 5. Reference numeral 7 denotes a PD which receives a display control signal (8 bits) from the ROM and controls the X driver 8 and the Y driver 9 to perform appropriate display on the PDP panel 10.
P controller.

FIG. 12 is a diagram showing a relationship between a driving waveform of a PDP and a display control signal, where Yn and Xn represent output waveforms of an arbitrary Y driver and an X driver, respectively. FIG.
In 2, the write pulse is scanned from the Y driver 9, and the cells in one line emit light, and light is emitted again in the sustain by the next X driver. Here, the X driver outputs a data selection pulse according to the data transferred to the X side, and the display cell cancels the erase pulse output from the Y driver. An erase pulse is applied to the non-display cells, and the subsequent display is not performed. And X, Y
The display is maintained only in the display cells by the sustain pulses applied alternately, and the display is continued until the data is written again.

According to the prior art, as shown in the time chart of FIG. 11, the pulse signals input from the APC pulse generator 2 and the BC pulse generator 4 are

(Equation 2) To generate the APC signal and the BC signal, respectively.
The display control signal is created by the AND circuit. At this time, the rise of each signal is

(Equation 3) The BC signal cycle is short and the APC cycle is long and always stable. However, regarding the falling edge of each pulse, the current and volume change continuously.

(Equation 4) The timing when the logic is determined when latching is 1

(Equation 5) May be off. The length of the high luminance period of the BC signal is B
1 every several C cycles

(Equation 6) Due to the replacement, the entire display screen may look like flicker. Also, this is one of the BC signals every several cycles of the APC cycle.

(Equation 7) When the change occurs, the cycle becomes longer, so that it becomes easier for the human eye to see (it becomes noticeable when the frequency is lower than 60 Hz), and there is a disadvantage that display flicker is seen.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a display device which is particularly advantageous in achieving high luminance, a large screen, and multi-color display. It is another object of the present invention to provide a display device and a control method of the display device for controlling a large-sized, high-definition display device having a large display capacity and a large power consumption to reduce the power consumption. .

[0007]

A display device and a control method of the display device according to the present invention basically employ the following technical configuration in order to achieve the above object. That is, according to a first aspect of the present invention, in a display device control method using a sustain discharge pulse, a signal based on a detected drive voltage is converted from analog to digital and supplied to an arithmetic processing circuit, and the arithmetic result there is obtained. The control signal is supplied as binary data to a luminance control circuit that controls the frequency of the sustain discharge pulse, and the arithmetic processing circuit section performs a comparison operation between the converted signal and a predetermined reference value. A brightness control circuit, based on the supplied binary data, a control method of the display device for controlling the frequency of the sustain discharge pulse so that the power consumption value of the display device becomes equal to or less than a desired constant value; According to a second aspect of the present invention, in a display device using a sustain discharge pulse, voltage detecting means for detecting a drive voltage and a signal based on the detected voltage value are applied. A / D to log / digital conversion
Performs an operation based on the converter and the converted signal,
An arithmetic processing circuit for outputting a control signal based on the operation result as binary data; and a brightness control for controlling the frequency of the sustain discharge pulse based on the binary data so that the power consumption value of the display device becomes a desired constant value or less. The display device includes a circuit, and the operation in the arithmetic processing circuit unit includes execution of a comparison operation between the converted signal and a predetermined reference value.

[0008] Since the control method of the display device according to the present invention has the above-mentioned technical configuration, when the operation of the APC function is performed, first, the drive voltage of the device is detected, and the analog / digital conversion is performed. A luminance level control signal based on binary data is sent to a circuit that takes in the MPU, performs a comparison operation with a reference value, and controls the number of discharge sustaining pulses, and controls the circuit. Also, when there is an external brightness control signal, the brightness control voltage is similarly converted from analog to digital and taken into the MPU. Therefore, the parallel control of the external brightness adjustment operation and the APC function in the present invention can be performed only by calculation (firmware) in the MPU, and the data sent to the control circuit for the number of discharge sustain pulses is the same. There is no problem such as flicker in the method of controlling the discharge frequency.

The APC function and the brightness adjustment function used in the present invention are defined as follows. (1) APC function: detects the average current value of the display discharge current in order to make the power consumption constant (current convergence point),
Controls the sustain frequency. (2) Brightness adjustment function: Sustain frequency variable resolution 6
The brightness variable control is performed in a range of 4 (6 bits).

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a specific example of a control method of a display device according to the present invention will be described below in detail with reference to the drawings. That is, FIG. 1 shows a specific example of a display device used in the display device control method according to the present invention.

FIG. 1 shows a display device 10 according to the present invention.
FIG. 2 is a block diagram showing an example of 0, a current detection unit 1, an external brightness adjustment unit 3 composed of a volume, a calculation unit 13 to which outputs of the current detection unit 1 and the external brightness adjustment unit 3 are input, and image data. DATA-R (8), DATA
-G (8), DATA-B (8), vertical sync signal

(Equation 8) , Horizontal sync signal

(Equation 9) And clock signal

(Equation 10) Controller 11, a data controller 12 connected to the output of the interface controller 11,
1 connected to the output of the arithmetic means 13 and the Y-driver 15 connected to the output of the driver controller 14 and driving the Y electrode of the display panel 10 and connected to the Y pulser 16 ,
An X pulser 18 connected to an output of the driver controller 14 and driving an X electrode of the display panel 10;
And address drivers 17 and 19 connected to the output of the driver controller 14 and connected to the output of the data controller 12, and supplying appropriate image display data to the X electrodes of the display panel 10. It is.

The present invention is applied to a display unit or a display device which is advantageous for high brightness, large screen, multi-color display, etc. among displays. 2. Description of the Related Art A display device, in particular, a large-sized and high-definition display having a large display capacity and a large power consumption, requires a control of the power consumption in accordance with the display rate. Further, the display device may be flat or curved.

In the display device 100 using the above-described sustain discharge pulse, as one mode of the method for controlling power consumption according to the present invention, for example, power consumption is detected as a change in current by an appropriate current detection means. The configuration is such that the sustain discharge pulse frequency of the sustain discharge pulse waveform is controlled so that the power consumption value becomes equal to or less than a desired constant value.

That is, in the automatic power control (APC) of the present invention, an upper limit of the power consumption is set, and the power consumption is controlled so as not to exceed the upper limit. Therefore, the lower limit of the power consumption is not particularly controlled. Hereinafter, the automatic power control (APC) according to the present invention will be described with reference to FIG.
The method and its function will be specifically described.

FIG. 2 is an enlarged block diagram showing a main part of the display device 100 according to the present invention shown in FIG. 1, and the same parts and circuit components as those in FIG.
The same reference numerals are given as. That is, in FIG. 2, the external brightness adjustment volume 3, the current detection means 1, and the analog switch means 22 connected to the panel drive voltage power supply Vs are input to the calculation means (MPU) 13.

Further, the arithmetic means (MPU) 13 includes A
/ D converter 131, arithmetic processing circuit 132, input / output port 133, and control firmware 134
The output of the arithmetic means (MPU) 13 is connected to a control terminal connected to a control circuit 14 as a driver controller, terminals P11 and P21 for setting an automatic power consumption control (APC) response time, and And terminal portions P22 and P23 for setting the brightness adjustment time.

When the automatic power control (APC) according to the present invention is executed in the display device 100, for example, the current consumption of the device driving high-voltage power supply Vs flows as a peak current. The voltage is converted into a voltage value of an average current by an integration circuit attached to the detection means 1, and converted into a digital value by an analog / digital converter 131.
The data is taken into the arithmetic processing unit 132 as 6-bit 64-stage binary data in U. The arithmetic processing unit 132 compares the reference value (the reference value of the APC convergence value) set from the beginning.
C0-5) are output from the output ports (P01-P06) as they are. If it is higher than the reference value, the current luminance set value is reduced to operate the APC function. For example,
Decreases the current value by -1. This operation is called the vertical sync signal.

[Equation 11] Is performed once per cycle. Based on the control signal of the brightness setting value, the brightness control circuit performs variable control of the number of sustain pulses (discharge frequency) generated within one cycle of the vertical synchronization signal, and controls brightness of the entire screen (power consumption control). It can be performed. Thus, the power consumption can be reduced to the APC convergence value by sequentially decreasing the luminance set value by −1 and repeating until the acquired data becomes the same value as the set reference value.

Further, the automatic power consumption control (A
In the PC) method, when the power consumption value is controlled to a predetermined value with respect to the basic configuration described above, the automatic power consumption control is started when the display ratio on the display device is increased. It is preferable that the luminance decrease and the luminance increase at the time of exiting from the automatic power consumption control when the display rate is reduced have a temporal change.

Therefore, for example, it is also desirable to give a hysteresis characteristic to the luminance change. That is, when the above-described hysteresis characteristic is realized, for example, when the display ratio in the display device is increased, the brightness is gradually decreased at the start of the automatic power consumption control, and the display ratio is reduced. In this case, it is possible to have a temporal change so as to rapidly increase the brightness when exiting from the automatic power consumption control.

Next, FIG. 3 shows response characteristics of current consumption and luminance with respect to display rate when the above-described automatic power control (APC) method according to the present invention is implemented. FIG. 3 shows a state in which the power consumption ratio, the luminance ratio, the display ratio, and the external luminance adjustment are changed with respect to the time axis. The automatic power control (APC) operation start level (APC convergence value) is shown. The case where the power consumption ratio is set to 60% (0.6) is shown.

As is apparent from FIG. 3, it is assumed that the level of the external brightness adjustment is initially set to the maximum (MAX) value. That is, in the period from time t0 to time t2, the display rate is set to 100%,
When the display device is started to be driven at 0, the power consumption ratio first rises to 100% (1.0), so that the APC operation is started. Thereafter, as shown by the line segment (a), the power consumption ratio is increased. Gradually lower the power ratio. At time t1 when the power consumption ratio becomes 0.6, which is the preset APC operation start level (APC convergence value), the power consumption ratio is maintained at a constant value as shown by the line segment (b) until time t2. I'm sullen.

That is, when the display ratio rises to 100% and the power consumption exceeds the APC convergence value, first, the discharge frequency is not changed and the luminance is set to the maximum value, and thereafter, the luminance is sharply reduced. To avoid causing a change in image quality and to prevent a change in luminance from being sensed by human senses, as shown by a line (a), for example, take a maximum of about 10 seconds, APC while gradually lowering the power consumption ratio
The convergence value is changed.

In other words, the discharge frequency is reduced over time in order to reduce the luminance naturally. In response to the change in the power consumption ratio, the luminance ratio also gradually decreases from the maximum value, and at time t1, the luminance decreases to 50%, and between the times t1 and t2, the luminance ratio is fixed at a constant value of 50%. Will be done.

Thereafter, at time t2, the display rate becomes 50
%, And when the power consumption ratio falls below the APC convergence value 0.6, the power consumption rapidly decreases as shown by the line segment (c), but the APC operation is canceled. The luminance ratio can be immediately restored to 100%. That is, the automatic power consumption control (AP
In the method C), when the APC operation is exited due to the decrease in the display ratio, that is, the increase in luminance can be rapidly realized without time.

Thereafter, since the display rate is kept at 50% until time t3, there is no change in the power consumption ratio and the luminance ratio. At time t3, the external luminance adjustment is performed at the display rate of 50%. Is changed to the minimum value (MIN), both the power consumption ratio and the luminance ratio decrease rapidly, and both are fixed at the predetermined levels at time t4. Thereafter, at time t5, if the display ratio is changed to 100% again, the power consumption ratio slightly increases, but the luminance ratio hardly changes. At time t6, when the level of the external brightness adjustment is set to the maximum (MAX) value again, as a result, the power consumption ratio and the brightness ratio increase rapidly, and at time t7,
When the power consumption ratio exceeds the APC convergence value (0.6), A
The PC operation is activated, and the power consumption ratio becomes the APC convergence value (0.
6), and at the same time, the luminance ratio is fixed at a level of approximately 0.5.

Thereafter, at time t8, the display rate is reduced to 50% while the external brightness adjustment is set to the maximum (MAX) value.
, The power consumption ratio becomes the APC convergence value (0.
6), but the luminance ratio rises rapidly to 100%. Thereafter, the display rate becomes 100% again at time t9.
Is returned to the state at time t0.

FIG. 4A is a graph showing an example of a display ratio-to-power consumption ratio characteristic used in the present invention.
When the PC convergence value is set to 0.6 and the APC convergence value (0.6) is exceeded, the APC operation is activated and the power consumption ratio is fixed to the APC convergence value (0.6). By operating the external brightness adjustment, it is possible to change the slope of the characteristic graph of the power consumption ratio.

FIG. 4B is a graph showing an example of the display ratio-luminance ratio characteristics used in the present invention.
While the PC operation is not operating, the luminance ratio is at the level of 1.0, but when the APC operation is activated, the level gradually decreases to reach the level of 0.5. It is possible to change the maximum value of the luminance ratio by operating.

In the present invention, the APC function controls the sustain frequency by detecting the average value of the display discharge current in order to maintain a constant power consumption (current convergence point). Performs variable brightness control in the range of the sustain frequency variable resolution 64 (6 bits). Next, the procedure of the arithmetic processing operation of the control firmware of FIG. 2 when executing the above-described automatic power control (APC) according to the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 5A is a flowchart showing a main routine which is a basic operation. After the start, an initialization operation is performed in step (1). That is,
In the step (1), initialization of each CPU board, setting of an interrupt method, an interrupt vector, etc., setting of a stack point, and the like are performed. In step (2), initialization is performed, and specifically, setting of each port (for example, sustain high voltage waveform output, address high voltage waveform output is in a non-operating state), register initial setting, and the like are performed. I do.

In step (3), 6 bits 64
This is a step in which the gradation control operation is performed.
An arithmetic process for outputting B0 to B5 is performed. In step (4), the process of determining whether to permit the interrupt

(Equation 12) Execute interrupt every time. Step (5) is an interrupt waiting step for executing an interrupt routine.

FIG. 5B shows a flowchart of the interrupt processing routine executed in step (5) in FIG. 5A. After the interrupt, in step (1), the APC convergence value fetch processing is performed. The operation is performed,
In step (2), APC processing is executed, and in step (3), a brightness change operation is executed.

FIG. 5C is an APC convergence value fetching routine for executing the APC convergence value fetching processing operation of step (1) in the flowchart of FIG. 5B.
In step (1), a predetermined APC convergence value (AN0) is selected, and in step (2), A / A
D conversion is performed, and the value is stored in an APC convergence point register (AAP) in step (3).

FIG. 5D shows an example of the A / D conversion processing routine of step (2) in this flowchart. FIG. 5E is an MCB0-5 setting routine showing an example of an arithmetic processing operation for outputting MCB0-5 in step (3) in the flowchart of FIG. 5A. Then, the value (AN1) of the external brightness adjustment volume is selected, A / D converted in step (2), and the value is converted to M in step (3).
The data is output to CB0 to CB5, and the value is stored in an MCB register (MCB) in step (4).

FIG. 5D shows an example of the A / D conversion processing routine of step (2) in this flowchart. Next, FIG. 6A is an APC processing routine for executing the APC processing operation of step (2) in the flowchart of FIG. 5B, and the APC convergence time is set in step (1). Register (CAPU)
Is added to 1 to form a new (CAPU). In step (2), the APC convergence time data (CAP) is compared with the value of the APC convergence time register (CAPU), and (CAP) is (CAPU), then E
Proceeding to XIT, if (CAP) is the same as (CAPU), proceed to step (3), set the APC convergence time register (CAPU) to 0, and proceed to step (4).

In step (4), the contents of the external brightness adjustment volume VR are fetched and the value is set in a brightness adjustment register (BRT). In step (5), the average current Is of the consumed current is calculated. Detect and average current value register I
Set to S. Then, in step (6), A
The PC convergence point data (AAP) is compared with the value set in the average current value register IS. If the value set in the average current value register IS is less than the APC convergence point data (AAP), , EXIT, and if it is larger than (AAP), the process proceeds to step (7), where 1 is subtracted from the value of the MCB register, and the result is newly stored in the MCB register.
It goes to.

In the routine of FIG. 6A, in steps (1) and (2), APC processing is not performed for each interrupt processing routine (once per frame period). , A predetermined time can be made to wait.
That is, the response time of APC convergence can be variably set. On the other hand, FIG. 6B is a brightness change routine for executing the brightness change processing operation of step (3) in the flowchart of FIG.
In step (2), 1 is added to the brightness adjustment time register (CBRU) to make a new (CBRU), and in step (2), the value of the brightness adjustment time register (CBRU) and the brightness adjustment time data (CBR) And the value of (CBR)
Is greater than (CBRU), go to EXIT,
If (CBR) is the same as (CBRU), the process proceeds to step (3) where the brightness adjustment time register (CBR)
U) is set to 0 and the process proceeds to step (4).

In step (4), the value of the APC convergence point register (AAPB) is compared with the value set in the average current value register IS, and the value set in the average current value register IS is compared. Is smaller than the value of the APC convergence point register (AAPB), the process proceeds to step (5), where the value of the brightness adjustment register (BRT) and the value of the MCB register are compared, and the brightness adjustment register (BRT) is compared. If the value of the MCB register is not larger than the value of the MCB register, the process proceeds to step (6), where the value of the brightness adjustment register (BRT) is compared with the value of the MCB register. BRT) is M
If the value is not smaller than the value of the CB register, the process proceeds to step (7), and the data of MCBs 0 to 5 are set.
In step (8), the data of the MCBs 0 to 5 is output.

On the other hand, in step (4), if the value set in the average current value register IS is larger than the value in the APC convergence point register (AAPB),
Proceeding to step (9), the value of the brightness adjustment register (BRT) is compared with the value of the MCB register. If the value of the MCB register is not larger than the value of the brightness adjustment register (BRT), the process proceeds to step (9). Proceed to (7), but the MCB
If the value of the register is larger than the value of the brightness adjustment register (BRT), the process proceeds to step (10), where 1 is subtracted from the value of the MCB register and the result is newly added to the MCB register.
The value is stored in the register and the process proceeds to step (7).

If it is determined in step (5) that the value of the brightness adjustment register (BRT) is larger than the value of the MCB register, the process proceeds to step (11), and 1 is set to the value of the MCB register. The result of the addition is newly stored in the MCB register, and the flow advances to step (7). Similarly, in step (6), when the value of the MCB register is larger than the value of the brightness adjustment register (BRT), the process proceeds to step (12), where 1 is subtracted from the value of the MCB register. The result is newly stored in the MCB register, and the flow advances to step (7).

By executing such a routine, the average power consumption value IS as shown in FIG. 6C is controlled. In the present invention, as described above, the external brightness control function is configured to operate in parallel with the automatic power consumption control (APC). The control function is operated by an external volume mechanism.

The meanings of the respective symbols shown in the above flowchart and their initial setting values are as follows. <Initial setting> (CAP): APC convergence time data -8 (variable) (CAPU): APC convergence time register 0 (CBR): Brightness adjustment time data -2 (variable) (CBRU): Brightness adjustment time register 0 (AAP) ): APC convergence point data (AAPB): APC convergence point register (BRT): Brightness adjustment register (IS): Is average current value register (MCB): MCB register Also, when external brightness adjustment is performed, Analog / digital conversion of signal voltage in the same way as current detection
And outputs predetermined luminance control signal data from the port as a luminance setting value. When the APC function is operating, the brightness control signal data whose external brightness has been adjusted is output when the current consumption is smaller than the APC set value, and when the current consumption is larger than the APC set value, the APC operation is performed.
The brightness control signal data corresponding to the convergence value is output.

In the above control method, as described above, A
As the control when the external brightness is variable during the PC operation,
FIG. 6 is a flowchart of a process for executing a process in which the brightness is not changed until the brightness adjustment range falls below the APC convergence value.
(B) shows an APCon processing routine of the brightness change routine. Further, in the case of a measure for varying the brightness by multiplying the APC convergence value by a value proportional to the external brightness adjustment value, it is possible to leave the APCon processing unit as it is and calculate and vary the APC convergence value.

In the above power consumption control method, the response speed of the APC function operation and the response speed to the external brightness variable information can be independently varied by providing setting switches at the input ports of the MPU. APC function operation response speed information is provided to ports P11 and P21 in FIG.
External brightness variable response speed information is input to the ports P22 and P23, and the MPU changes the initial setting values of the APC convergence time data and the brightness adjustment time data in accordance with the information. In this setting, four stages of time setting are possible.

Further, in the power consumption control, the average current value Is as detected power is converted into a voltage by an integrating circuit, analog-to-digital converted, and compared with a reference value which is an APC convergence value by an MPU. However, since the optimal setting voltage of the drive voltage differs depending on the device used, actually, the actual power consumption differs depending on each device. Therefore, the drive voltage is divided by resistors and analog /
It is also possible to convert the digital value, take it into the MPU, change the convergence value of the APC by the drive voltage, and keep the power consumption constant. This makes it possible to control the power consumption value of the unit more accurately, and also to alleviate the luminance variation (during the APC operation) caused by the different set voltage for each device.

In the power consumption control method of the present invention,
When the display rate is equal to or higher than a certain display rate, the power consumption is controlled based on the APC convergence value.
By varying the discharge frequency in accordance with the value of the taken power consumption, it is possible to dynamically control the luminance at light load. That is, as is clear from the power consumption / luminance characteristics shown in FIGS. 7 and 8, when the power consumption is less than the APC convergence value, the power consumption can be increased to increase the luminance, and the luminance ratio temporarily exceeds 100%. Can also be used.

Since the device used in the present invention is a discharge tube, a decrease in luminance occurs when the device is used for a long time. Therefore, the use period of this device is monitored by an appropriate device as shown in FIG. 9, for example, a timer 91 and a counter 92, and it is detected that a certain period of time has elapsed. By increasing the value for each value, it is possible to alleviate the luminance reduction speed. If the MPU 13 port can use 4 bits,
It is possible to change the APC convergence value in 16 steps. However, in this method, since the APC convergence value is increased on the way, the system cannot be operated with MAX power consumption in the initial use.

Here, a specific embodiment of the APC control method according to the present invention is summarized as follows. A flat display having display cells arranged on a matrix orthogonal to XY is displayed by giving a memory function to the panel. Using the device,
In a unit using a driving method in which the brightness of the display, that is, the brightness is determined by the number of sustain pulses, the power consumption proportional to the brightness is detected by the current, and the power consumption is reduced to a desired constant value or less. An automatic power control function (APC function control method) for automatically controlling the number of sustain pulses. In the above power control method, a desired power consumption value (hereinafter referred to as an APC convergence value) is automatically controlled. In order to make the luminance change naturally, the luminance change at the start of the APC operation when the display ratio is UP and the luminance increase when exiting from the APC operation when the display ratio is DOWN are delayed, and the luminance change is performed. This is a control method in which a time hysteresis characteristic is provided.

According to the present invention, in the power consumption control system having the above-described configuration, the APC function and the external brightness adjustment function are operated in parallel, so that the APC function is adapted to the use of the display device.
It is also possible to adopt a control method having a function of selecting the external brightness adjustment function priority during operation as follows. (A) Priority is given to the APC function. During the APC operation, the brightness is not changed until the brightness adjustment range becomes equal to or less than the APC convergence value.

(B) Prioritize external brightness adjustment—During the APC operation, the brightness is varied by multiplying the APC convergence value by a value proportional to the external brightness adjustment value. That is, the automatic power consumption control function (AP
C function) and the external brightness control function are configured to operate in parallel, and one of the automatic power consumption control function (APC function) and the external brightness control function is given priority. The automatic power consumption control function (APC function) may be preferentially selected. In this case, when the automatic power consumption control is in operation,
Until the brightness adjustment range falls below the automatic power consumption convergence value,
It can be configured so that the control is executed so that the brightness does not change, and when the external brightness control function is preferentially selected, during the automatic power consumption control,
The automatic power consumption convergence value is multiplied by a value proportional to the external brightness adjustment value so that the control is executed so as to change the brightness.

Further, when the automatic power consumption control function (APC function) and the external luminance control function are configured to operate in parallel, they are introduced via the external luminance control function. Response speed to the external brightness variable information;
The operation speed of the automatic power consumption control function (APC function) can be variably set independently of each other.

Also, the automatic power consumption convergence value in the present invention can be configured to be variable according to the panel drive voltage, whereby the appropriate voltage differs for each panel. Even in this case, the power consumption value of each unit can be controlled more accurately by changing the APC convergence value. When the display rate is equal to or less than a predetermined value and indicates a light load state, the automatic power consumption convergence value is adjusted to the display rate so that the luminance becomes higher as the load becomes lighter. It is also possible to control the automatic power consumption convergence value if the operation time of the display device is detected and the operation time has passed a predetermined time. It can be controlled to change,
In that case, it is desirable to set the automatic power consumption convergence value higher.

As a display device capable of executing the automatic power consumption control (APC) function in the present invention, for example, in a display device 100 using a sustain discharge pulse, power consumption is detected by current. The display device comprises a current detecting means 1 and a control means 13 for controlling a sustain discharge pulse frequency of the sustain discharge pulse waveform so that the power consumption value becomes equal to or less than a desired constant value. In controlling the power consumption value to a predetermined value, when the display ratio of the display device increases, the brightness decreases at the start of the automatic power consumption control and when the display ratio decreases. It is desirable to have a control means for controlling the luminance rise when exiting from the automatic power consumption control in order to have a temporal change.

Further, in the display device according to the present invention, the control means 13 has a function of giving a hysteresis characteristic to the luminance change, and an external luminance control means 3 is added. It is desirable to have. The external brightness control means 3 includes an external volume, and the control function (APC) of the automatic power consumption control means.
Function) and the control function of the external brightness control means are configured to operate in parallel, and one of the automatic power consumption control function (APC function) and the external brightness control function is prioritized. It is necessary that a selection means that can be selectively selected be added.

[0055]

According to the control method and the display device of the display device according to the present invention, the display device is particularly advantageous for high brightness, large screen, multi-color display, etc. among the display devices. A large, high-definition display device with a large capacity, and
In a display device that consumes a large amount of power, control for reducing the power consumption can be easily and simply performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a specific example of a display device according to the present invention.

FIG. 2 is an enlarged block diagram of a main part of a specific example of the display device according to the present invention.

FIG. 3 is an automatic power consumption control (AP) according to the present invention;
C) A graph showing the response characteristics of the power consumption ratio and the luminance ratio in the operation.

FIG. 4 (A) is a graph showing a display ratio versus power consumption ratio characteristic in the present invention, and FIG. 4 (B) is a graph showing a display ratio vs. luminance ratio characteristic in the present invention. It is.

5 (A) to 5 (E) are flowcharts illustrating a procedure of an automatic power control (APC) processing operation used in the present invention.

FIGS. 6 (A) to 6 (C) are flowcharts for explaining a procedure of an automatic power consumption control (APC) processing operation used in the present invention.

FIG. 7 is a graph showing a characteristic of a display ratio to a power consumption ratio in a dynamic APC operation according to the present invention.

FIG. 8 is a graph showing a display ratio-to-luminance ratio characteristic of the dynamic APC operation according to the present invention.

FIG. 9 is a block diagram illustrating a configuration for improving a temporal change in luminance of a display device.

FIG. 10 is a block diagram showing a conventional automatic power control (APC) mechanism of a display device.

FIG. 11 is a time chart in a conventional automatic power control (APC) method for a display device.

FIG. 12 is a diagram showing a relationship between a PDP panel drive waveform and a display control signal in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Current detection means 2 ... APC pulse generation means 3 ... External luminance adjustment means, volume 4 ... BC pulse generation means 5 ... Latch and AND circuit 6 ... Luminance selection ROM 7 ... PDP controller 8 ... X-driver 9, 15 ... Y -Driver 10 ... PDP panel, display panel unit 11 ... Interface controller 12 ... Data controller 13 ... Calculation means, MPU 14 ... Control circuit, driver controller 16 ... Y pulser 17, 19 ... Address driver 18 ... X pulser

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigehisa Tomio 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Tomokatsu Kishi 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited ( 72) Inventor Hirohito Kuriyama 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited

Claims (6)

[Claims] In a control method of a display device using a sustain discharge pulse, a signal based on a detected drive voltage is converted from analog to digital and supplied to an arithmetic processing circuit, and based on an arithmetic result in the arithmetic processing circuit. The control signal is supplied as binary data to a brightness control circuit that controls the frequency of the sustain discharge pulse. The calculation in the calculation processing circuit unit performs a comparison calculation between the converted signal and a predetermined reference value. The brightness control circuit controls the frequency of the sustain discharge pulse based on the supplied binary data so that the power consumption value of the display device becomes equal to or less than a desired constant value. A method for controlling a display device. 2. The method according to claim 1, wherein a luminance control signal from the outside is converted from analog to digital and taken into said arithmetic processing circuit, and arithmetic processing is performed in said arithmetic processing circuit using said converted signal as a parameter. 2. The method for controlling a display device according to claim 1. 3. The method according to claim 2, wherein the external brightness control signal is supplied by an external volume mechanism. 4. A display device using a sustain discharge pulse, a voltage detecting means for detecting a drive voltage, and an analog-to-digital converter for converting a signal based on the detected voltage value into an analog signal.
A / D converter, an arithmetic processing circuit unit that performs an operation based on the converted signal, and outputs a control signal based on the operation result as binary data, and a power consumption value of the display device is equal to or less than a desired constant value. A brightness control circuit that controls the frequency of the sustain discharge pulse based on the binary data, wherein the calculation in the arithmetic processing circuit unit is performed by comparing the converted signal with a predetermined reference value. A display device comprising execution. 5. A luminance control means for externally performing luminance control, wherein the luminance control signal supplied from the luminance control means is converted from analog to digital and taken into the arithmetic processing circuit section, and the converted signal is outputted. The control method for a display device according to claim 4, wherein the calculation in the calculation processing circuit unit is performed using the parameter as a parameter. 6. The display device according to claim 5, wherein said external brightness control means includes an external volume.