JPH11338437A - Portable information terminal device with low power consumption display function - Google Patents

Abstract

(57) [Problem] To provide a portable information terminal device that can easily determine that the portable information terminal device body is operating while realizing low power consumption with a simple configuration. A required operation is input from an input device, and a color liquid crystal control unit reads display data from an image memory based on the input and sends the display data to a color liquid crystal display device. Data is displayed, and furthermore, a time monitoring means 6 for measuring the time when there is no input from the input device is provided, and when it is detected that a predetermined time has elapsed without any input, the amount of display data read from the image memory is reduced. To reduce power consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable information terminal device having a low power consumption display function having a color liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, in a portable information terminal device having a low power consumption display function having a color liquid crystal display device, low power consumption is realized by turning off the color liquid crystal display device when unused time continues. Was.

However, in the above-described conventional method for realizing low power consumption by the portable information terminal device, the color liquid crystal display device is turned off, so that the entire portable information terminal device is off or the color liquid crystal display device is not turned on. It is difficult to determine whether only the display is in the off state, and there is a problem that it is necessary to provide another display device or the like.

Further, for the purpose of reducing power consumption, a device described in Japanese Patent Application Laid-Open No. 7-64665 has been proposed. It is as shown in FIG. That is, FIG. 2 is a block diagram showing a configuration of a conventional display control device having a low power consumption function. In FIG. 2, 11 is an LCD display device, 12 is a driver, 13 is a display control unit,
14 is a multiplexer, 15 is a CPU, 16 is a ROM,
17 is a RAM, 18 is a display memory, and 19 is a detection unit.

Next, the operation of the above-mentioned conventional display control device will be described with reference to FIG. Normally, when displaying on the LCD 11, first, information to be displayed is written from the RAM 17 or the like into the display memory 18, and the LCD is controlled by the display control unit 13.
11 is displayed. However, if various information data is not written into the display memory 18 within a predetermined time and the storage contents are not changed, the detecting unit 1
By not setting the flag inside 9, the display timing is delayed. That is, when there is no writing to the display memory 18, the flag inside the detection unit 19 is not set, and the multiplexer 14
Selects a clock signal having a half frequency and delays the display timing on the LCD 11.

[0006]

In the conventional display control device as shown in FIG. 2, when the display device is not used, the clock signal is set to 1/2 frequency to delay reading from the display memory. Thus, the display timing is delayed to reduce power consumption. However, doing so complicates the configuration of the device,
There was a problem that the display screen became dark.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. By limiting the amount of display data read from an image memory when the portable information terminal is not in use, a low power consumption with a simple configuration is achieved. It is an object of the present invention to provide a portable information terminal device which can easily determine that the main body of the portable information terminal device is operating while realizing the above.

[0008]

According to the portable information terminal device of the present invention, a necessary operation is inputted from an input device, and a color liquid crystal control means reads out display data from an image memory based on the input and supplies the read data to a color liquid crystal display device. The color liquid crystal display device is a portable information terminal device configured to display received display data, and further includes time monitoring means for measuring a time period during which there is no input from the input device, and a predetermined time period without any input. When the elapsed time is detected, the amount of display data read from the image memory is reduced.

According to the present invention, when it is detected that a predetermined time has passed without any input from the input device, the amount of display data read from the image memory is reduced.
A portable information terminal device that can easily determine that the main body of the portable information terminal device is operating while realizing low power consumption with a simple configuration is obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The liquid crystal display device according to the first aspect of the present invention comprises an input device for inputting by operation, an image memory for storing display data, and a display device for reading display data to be displayed from the image memory. A liquid crystal display device comprising a color liquid crystal control means for sending to the liquid crystal display device, and a color liquid crystal display device for displaying display data sent from the color liquid crystal control means, further comprising a time period during which no input is made to the input device. Time monitoring means for measuring and detecting when a predetermined time has elapsed, and reducing the amount of display data read from the image memory when the time monitoring means detects that there has been no input to the input device for a predetermined time. With a simple configuration, low power consumption can be realized and battery usage time can be extended, and the liquid crystal display device It has an effect that it is possible to easily determine that they are created.

According to a second aspect of the present invention, there is provided a portable information terminal device comprising the liquid crystal display device according to the first aspect, and a display which is read out from an image memory when it is detected that there has been no input by a predetermined time operation. It is designed to reduce the amount of data. With a simple configuration, it is possible to achieve low power consumption and extend the use time of the battery, and to easily determine that the main body of the portable information terminal device is operating. It has the effect of being able to.

According to a third aspect of the present invention, in the portable information terminal device, the amount of display data read from the image memory is reduced by thinning out the read coordinates of the display data from the image memory. This has the effect of reducing the power used to read display data from the image memory.

According to a fourth aspect of the present invention, in the portable information terminal device, the amount of display data read from the image memory is reduced by partially reading the color information, and the display data is read from the image memory. This has the effect of reducing the power used for

According to a fifth aspect of the present invention, in the portable information terminal device, a portion of the display data which has been reduced and not read at the time of reading from the image memory interpolates neighboring display data or a fixed value. By interpolating other values into the portion of the display data that has not been read from the image memory, the resolution during the low power consumption period is improved.

According to a sixth aspect of the present invention, in the liquid crystal display method for a portable information terminal device, a necessary operation is input, display data is read from an image memory based on the input, and is sent to a color liquid crystal display device. A liquid crystal display method for a portable information terminal device comprising the steps of displaying display data read out from the color liquid crystal display device on a color liquid crystal display device, wherein a time during which no input has been made by an operation is measured, and a predetermined time without any input When the elapsed time is detected, the amount of display data read from the image memory is reduced, realizing low power consumption, extending the battery usage time, and operating the portable information terminal device. Has the effect of being able to easily determine that

(Embodiment) An embodiment of the present invention will be described below in detail with reference to the accompanying drawings and FIG. FIG. 1 is a block diagram showing a configuration of a portable information terminal device according to one embodiment of the present invention. In FIG. 1, 1 is a portable information terminal device, 2 is a color liquid crystal display device, 3 is a color liquid crystal control means, 4 is an image memory, 5 is an input device, and 6 is a time monitoring means.

Further, the configuration of the portable information terminal device according to the present embodiment will be described in detail. In the portable information terminal device 1, the color liquid crystal display device 2 is a device for displaying display data input from the color liquid crystal control means 3, and the image memory 4 stores values indicating colors to be displayed in the order of display coordinates. The liquid crystal control means 3 reads out display data from the image memory 4 at a timing necessary for display on the color liquid crystal display device 2 and sends it to the color liquid crystal display device 2.

The input device 5 is a device for inputting when operated by an operator, and the time monitoring means 6 measures the time during which no input has been made on the input device 5 and detects the passage of a predetermined time. 3 to output a power state control signal to reduce the amount of display data to be read, thereby causing the color liquid crystal display device 2 to transition to the low power consumption state.

Next, the operation of the portable information terminal device according to one embodiment of the present invention will be described with reference to FIG. First, when the power consumption control signal is not output from the time monitoring means 6 in the normal use state, that is, when the time during which there is no input to the input device 5 has not passed the predetermined time, the color liquid crystal control means Numeral 3 reads out all display data required by the color liquid crystal display device 2 from the image memory 4 and displays it.

At this time, the time monitoring means 6 always keeps the input device 5
While monitoring the input from, the time when there is no input is measured. When the measured time reaches a predetermined time, a power state control signal is output to the color liquid crystal control means 3 so that the color liquid crystal control means 3 restricts reading of display data. Make a transition to the state.

The color liquid crystal control means 3 may set the low power consumption state by, for example, reading out display data from the image memory 4 not at all coordinates but at every other coordinate so-called thinning-out. Or by performing control such that only half of the color information is read, the amount of reading from the image memory 4 is reduced. The data for the coordinates that have not been read are interpolated by the data of the adjacent coordinates, and the color information that has not been read is interpolated with a fixed value and sent to the color liquid crystal display means 2.

With this configuration, the amount of display data read out from the image memory 4 is reduced, and the portable information terminal 1
Power consumption can be reduced. In addition, by interpolating other data with respect to the coordinates of the data not read from the image memory 4, the amount of data to be displayed does not need to be reduced so much, and the reduction in the screen resolution can be suppressed to some extent.

In the present embodiment, when the color liquid crystal control means 3 is in the low power consumption state, the resolution of the display of the color liquid crystal display device 2 is reduced, and the display color is also limited. Since the time is not used, there is a high possibility that the color liquid crystal display device 2 is not gazing at the device. When the user starts using the color liquid crystal display device 2 again, the user operates the input device 5 to input data. Since the power state is stopped and all necessary display data is read out from the image memory 4 and sent to the color liquid crystal display device 2, the display becomes the original quality and does not pose a problem in use.

In this embodiment, as an example of means for reducing the amount of reading from the image memory, it is described that every other coordinate is read or half of the color information is read. The value does not need to be half, and it can be implemented by setting two coordinates and setting the color information to another value such as 1/3.

[0025]

According to the present invention, the readout amount of display data is reduced by arranging the data as described above, in particular, by thinning out the coordinates of the data to be read out from the image memory or reading out the color information partially. By doing so,
With a simple configuration, the power consumption of the portable information terminal device can be reduced to extend the use time of the battery, and it can be easily determined that the portable information terminal device body is operating.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a portable information terminal device according to an embodiment of the present invention;

FIG. 2 is a block diagram showing a configuration of a conventional display control device having a low power consumption function.

[Explanation of symbols]

 Reference Signs List 1 portable information terminal device 2 color liquid crystal display device 3 color liquid crystal control means 4 image memory 5 input device 6 time monitoring means 11 LCD 12 driver 13 display control unit 14 multiplexer 15 CPU 16 ROM 17 RAM 18 display memory 19 detection unit

Continued on the front page (51) Int.Cl. ⁶ Identification code FI G09G 5/00 550 G09G 5/00 550R H04N 9/30 H04N 9/30

Claims (6)

[Claims] An input device for inputting by operation; an image memory for storing display data; a color liquid crystal control means for reading display data to be displayed from the image memory and sending it to a color liquid crystal display device; A color liquid crystal display device for displaying display data sent from the means, further comprising a time monitor for measuring a time during which there is no input to the input device and detecting the time when a predetermined time has elapsed. Means for reducing the amount of display data read from the image memory when the time monitoring means detects that there has been no input to the input device for a predetermined time. 2. A liquid crystal display device according to claim 1, comprising:
A portable information terminal device characterized in that the amount of display data read from an image memory is reduced when it is detected that there has been no input by a predetermined time operation. 3. The portable information terminal device according to claim 2, wherein the amount of display data read from the image memory is reduced by thinning out the read coordinates of the display data from the image memory. 4. The portable information terminal device according to claim 2, wherein the amount of display data read from said image memory is reduced by partially reading color information. 5. The display data which has been reduced in reading from said image memory and which has not been read is interpolated with neighboring display data or a fixed value. 4. The portable information terminal device according to 4. 6. A required operation is input, display data is read from an image memory based on the input, and sent to a color liquid crystal display device, and the display data read from the image memory is displayed on the color liquid crystal display device. What is claimed is: 1. A liquid crystal display method for a portable information terminal device comprising the steps of: measuring a time during which no input has been made by an operation, and displaying an amount of display data to be read from the image memory when detecting that a predetermined time has elapsed without input A liquid crystal display method for a portable information terminal device, comprising: