JP3314615B2 - Terminal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal display (LC)
D, and a terminal device having a backlight for identifying the display status of the LCD.

[0002]

2. Description of the Related Art Generally, this type of LCD with a backlight is used.
When a keyboard or the like is operated in a terminal device having
Various display data based on the operation information are output to the LCD, and at this time, the backlight is turned on so that the display state of the LCD can be sufficiently identified. After that, the backlight is turned off when a certain time elapses without operating the keyboard or the like.

[0003]

However, when the amount of display on the LCD is large, it takes a long time to confirm this.
For this reason, there is a problem that the backlight is turned off during the confirmation of the display state and the confirmation becomes impossible. Here, if the lighting time of the backlight is increased to solve such a problem, the lighting state of the backlight continues for a certain period of time even though the confirmation of the LCD display screen has already been completed.
The device has a problem that wasteful power is consumed.
Accordingly, an object of the present invention is to make it possible to confirm all display data being displayed on the LCD and to reduce the power consumption of the apparatus at this time.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an LCD and a liquid crystal display arranged on the lower surface of the LCD.
In a terminal device having a backlight for turning on and off, monitoring means for turning on the backlight and monitoring the lighting time of the backlight, detecting means for detecting the amount of data displayed on the LCD, and detecting means And control means for variably setting the lighting time of the backlight according to the data amount detected by the control unit. Therefore, LC
The lighting time of the backlight is variably set according to the amount of data displayed in D, and the monitoring means monitors the lighting time, and turns off the backlight when the lighting time elapses.
Further, at least two or more lighting times of the backlight can be set. Further, the monitoring means is activated in response to a predetermined key operation or the like.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a terminal device according to the present invention. In the figure, 1 is a terminal device, 1
1 is a CPU for controlling the terminal device 1, 12 is a VRAM for storing display data, 13 is an LCD (liquid crystal) for inputting and displaying display data, and 14 is an LCD 13 for displaying display data of the VRAM 12 under the control of the CPU 11. L to transfer to
It is a CD controller.

Reference numeral 15 denotes a touch panel arranged on the upper surface of the LCD 13 for inputting various information, and 16 denotes a CPU which converts operation information of the touch panel 15 into digital signals and converts them into CPU signals.
An A / D converter for transmitting to the display 11, a backlight 17 disposed on the lower surface of the LCD 13 for identifying a display state of the LCD 13, a backlight power supply 18 for supplying power to the backlight 17, such as a battery, and a reference numeral 19. C
ROM storing a program to be executed by the PU 11,
0 is a RAM for temporarily storing data, 21 is another input / output unit for connecting an external device (not shown) to the terminal device 1, and 22 is a device power supply unit for supplying power to the above units.

[0007] In the terminal device 1 configured as described above,
When a touch key on the touch panel 15 is operated, the operation information is converted into a digital signal by the A / D converter 16 and transmitted to the CPU 11. In this case, CPU1
1 executes the program in the ROM 19 to obtain R
The display data stored in the AM 20 is transferred to the VRAM 12 and the LCD controller 14 is activated.
Then, the LCD controller 14 sequentially and periodically transfers the display data of the VRAM 12 to the LCD 13. In this case, when the CPU 11 turns on the backlight 17, the backlight 17 is turned on by the power supplied from the backlight power supply 18. As a result, the display data transferred and displayed on the LCD 13 can be identified (visually).

FIG. 4 is a view showing an example of the display screen displayed on the LCD 13 in this way. Thereafter, when the backlight lighting continuation operation is not performed on the touch panel 15 for a predetermined time, the CPU 11 turns off the backlight 17. Then, the backlight 17 is turned off, and the display screen of FIG. 4 cannot be identified.

By the way, the display screen shown in FIG.
FIG. 4 is a screen showing the maximum display amount of the CD 13.
The display screen shown in (b) is a screen showing the minimum display amount of the LCD 13. For a display screen having such a display amount variation, a backlight 17 for a time corresponding to the display amount is provided.
Is turned on, the backlight 17 is turned off after a lapse of time in which the display state is completely confirmed in the screen having the maximum display amount, and the display state is also changed in the screen having the minimum display amount. The backlight 17 is turned off immediately after the time to be confirmed elapses. Therefore, even when the display amount of the LCD 13 is large, all of this can be confirmed, and when the display amount is small, it is possible to avoid a problem that the backlight is still lit even after the display confirmation is completed.

FIG. 2 is a flowchart showing the operation of the CPU 11 of such a terminal device. The operation of the main part of the present invention will be described with reference to this flowchart. When the CPU 11 is started in step S1 by supplying power to the apparatus, the CPU 11 detects whether or not the touch panel 15 is operated. Here, it is determined in step S2 whether the detected operation of the touch panel 15 is a lighting operation of the backlight 17.

When the backlight 17 is turned on, the backlight 17 is turned on and L
The display data amount displayed on the CD 13 is determined in step S3.
Search by. That is, in this case, the display data in the VRAM 12 is counted. However, since it is difficult to read the data in the VRAM 12 from the CPU 11, the display data is actually counted in advance when the data is transferred from the RAM 20 to the VRAM 12.

Thereafter, the process proceeds to step S4, in which the lighting time of the backlight 17 is determined according to the amount of display data, and the lighting time is set in the internal timer 11a to start the time counting operation. Next, in step S5, the touch panel 1
5 detects the presence or absence of an operation, and detects the detected touch panel 15
It is determined in step S5 whether or not the operation is a lighting continuation operation of the backlight 17.

Here, if the operation of the touch panel 15 is an operation of continuing to turn on the backlight 17, the process returns to step S3, where the display data amount is counted again to determine the lighting time according to the data amount. During this time, the lighting of the backlight 17 is continued. If no operation is performed on the touch panel 15 or the operation is not an operation for continuing to turn on the backlight, the process shifts to step S6 to determine whether or not the lighting time has elapsed due to the time-up of the timer 11a.
Then, if the lighting time of the backlight 17 has not elapsed, the process returns to step S5, and it is determined whether or not there is an operation to continue lighting the backlight 17. When the lighting time of the backlight 17 has elapsed and the determination in step S6 is "YES", the backlight 17 is turned off in step S7.

As described above, the lighting time of the backlight 17 is variably set according to the amount of data displayed on the LCD 13. FIG. 3 is a flowchart illustrating a detailed operation of determining the lighting time of the backlight 17. Here, the LCD 13 can display up to 40 characters per line, and can display 30 lines. Therefore,
The LCD 13 can display up to 1200 (40 × 30) characters.

The flowchart of FIG. 3 will be described on the basis of such a premise. First, when data is displayed on the LCD 13 when the backlight is turned on (step S11), the number of display data is determined by the above-described method. Is counted and stored in the register X (step S12). If the count value is 400 characters or less ("YES" in step S13), 5 seconds is set as the value Y of the internal timer 11a and the timer is started (step S1).
5).

If the count value of the display data is within the range of 401 characters or more and 800 characters or less (step S14).
Is "YES"), 15 seconds is set as the value Y of the internal timer 11a and the timer is started (step S1).
6). If the count value of the display data is 801 characters or more ("NO" in step S14), 30 seconds is set as the value Y of the internal timer 11a and the timer is started (step S17).

As described above, when the display data amount is large, the lighting time of the backlight 17 is set long, and when the display data amount is small, the lighting time of the backlight 17 is set short. If the display amount is small, the power consumption of the device can be reduced because the backlight 17 is turned off immediately when the display amount is small. Therefore, the backlight 17
If a battery is used as a power source of the battery or a battery is used as a power source of the entire apparatus, it is possible to prevent early consumption of these batteries. In addition, early consumption of the LCD 13 and the backlight 17 can be prevented.

[0018]

As described above, according to the present invention, the monitoring means for turning on the backlight and monitoring the lighting time and the detecting means for detecting the amount of data displayed on the LCD are provided. The lighting time of the backlight is variably set according to the data amount detected by the means, so the lighting time of the backlight is set longer when the display data amount is large, and the lighting time is set when the display data amount is small. Is set short, even if the display amount of the LCD is large, all of this can be confirmed. If the display amount is small, the backlight can be turned off immediately after the display confirmation is completed, so that the power consumption of the device can be reduced. In addition, since at least two backlight lighting times can be set, the backlight lighting time can be set finely. Further, since the monitoring means is activated in response to a predetermined key operation or the like, the monitoring means can be easily activated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a terminal device of the present invention.

FIG. 2 is a flowchart showing an operation of a main part of the apparatus.

FIG. 3 is a flowchart showing a specific setting operation of a backlight lighting time in the device.

FIG. 4 is a diagram showing a display state of the device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Terminal device, 11 ... CPU, 11a ... Internal timer, 1
2 VRAM, 13 LCD, 14 LCD controller, 15 touch panel, 17 backlight, 18
Backlight power supply, 20 RAM, 22 device power supply unit.

Claims (3)

(57) [Claims] 1. An LCD , disposed on a lower surface of the LCD.
In a terminal device having a backlight for turning on and off, monitoring means for turning on the backlight and monitoring the lighting time of the backlight, and detecting means for detecting an amount of data displayed on the LCD, A terminal device comprising: control means for variably setting the lighting time of the backlight according to the data amount detected by the detection means. 2. The terminal device according to claim 1, wherein at least two or more lighting times of the backlight can be set. 3. The terminal device according to claim 1, wherein the monitoring unit is activated in response to a predetermined key operation or the like.