JPH10319920A - Portable electronic devices - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a portable electronic device capable of making a display easily viewable even in an outdoor or the like where the brightness around the device is high. SOLUTION: In response to a frame frequency switching instruction by a frame frequency switching instruction means 4a, a frame frequency control means 2 supplies a predetermined signal to a scanning signal supply means 6 which supplies a scanning signal according to the frame frequency to a liquid crystal display 5. The clock supply means 7 is controlled to supply a clock signal having a frequency corresponding to the frequency or another frame frequency, and the frame frequency is selectively switched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electronic device provided with a liquid crystal display, and more particularly to control of a frame frequency.

[0002]

2. Description of the Related Art Conventionally, portable electronic devices having a liquid crystal display include a handy terminal and an electronic organizer. In these portable electronic devices, the frame frequency of the liquid crystal display is fixed. Here, in such a liquid crystal display, the higher the frame frequency, the better the display contrast, but the higher the frame frequency, the higher the power consumption. The frequency is fixed to a lower frequency (around 70 Hz) so as not to cause interference.

[0003]

However, in such a conventional portable electronic device, when the frame frequency is fixed at a lower frequency in this manner, it is easy to see indoors where the brightness around the device is low, but it is easy to see around the device. There is a problem that the display becomes difficult to see outdoors or the like under sunlight where the luminance becomes extremely high.

Accordingly, the present invention has been made to solve such a conventional problem, and provides a portable electronic device which makes it easy to view a display even in an outdoor environment where the brightness around the device is high. The purpose is to do so.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a portable electronic device having a liquid crystal display, comprising: a scanning signal supply unit for supplying a scanning signal corresponding to a frame frequency to the liquid crystal display; Frame frequency switching instructing means for instructing to selectively switch from a predetermined frequency to another frequency, and clock supply means for supplying a clock signal having a frequency corresponding to a predetermined frame frequency or another frame frequency to the scanning signal supply means And controlling the clock supply means to supply a clock signal having a frequency corresponding to the predetermined frame frequency or another frame frequency to the scanning signal supply means in response to a frame frequency switching instruction by the frame frequency switching instruction means. And frame frequency control means. A.

The present invention is also characterized in that the frame frequency switching instruction means is configured to issue a switching instruction by manual operation.

Further, the present invention is characterized in that the frame frequency switching instruction means is configured to issue a switching instruction in accordance with the luminance around the liquid crystal display.

Further, the invention is characterized in that the frame frequency switching instruction means is constituted by an optical sensor for detecting luminance around the liquid crystal display.

Further, as in the present invention, in response to a frame frequency switching instruction by the frame frequency switching instruction means, the frame frequency control means supplies scanning signal supply means for supplying a scanning signal according to the frame frequency to the liquid crystal display. The clock supply unit is controlled to supply a clock signal having a frequency corresponding to a predetermined frame frequency or another frame frequency, and the frame frequency is selectively switched.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a portable electronic device according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a portable electronic device (hereinafter referred to as a device), and reference numeral 2 denotes a device. 1 (hereinafter referred to as MPU)
3) a memory for storing programs and data for controlling the device 1, 4 an input device for inputting data to the device 1, such as numeric keys and various function keys,
Reference numeral 5 denotes a liquid crystal display for displaying and outputting information.

Reference numeral 6 denotes a display controller which is a scanning signal supply means for controlling the liquid crystal display 5 and supplying a scanning signal to the liquid crystal display 5 in accordance with a frame frequency. The clock generator is a clock supply unit that supplies a clock signal having a frequency corresponding to a predetermined frame frequency or another frame frequency to the controller 6.

The input device 4 includes a liquid crystal display 5
A switching key 4a, which is an example of a frame frequency switching instructing means for manually performing an instruction to selectively switch the frame frequency from a predetermined frequency to another frequency, is provided, and the device 1 is taken outdoors under sunlight. When
The operator turns on the switching key 4a when the display becomes less visible than when the device is used indoors.

Here, when the switching key 4a is turned on, the MPU 2 controls the clock generator 7 to reduce power consumption as frame frequency control means, and controls the frequency of the clock signal supplied to the display controller 6. The predetermined frame frequency set at, for example, 70 Hz is increased to another frequency, and a high-contrast liquid crystal display is performed. The other frame frequency at this time may be previously set on the control program, for example, to a value determined to be 140 Hz which is twice the initial value, or may be programmed so that it can be input from the input device at the time of operation. Is also good.

When the apparatus 1 is used in an extremely bright place such as outdoors under sunlight, the frame frequency of the liquid crystal display 5 is increased by operating the switching key 4a, so that the liquid crystal display can be easily viewed. can do. Further, the operability of the device 1 can be improved.

The switching of the frame frequency is performed until the switching key 4a is turned off. When the switching key 4a is turned off, the frame frequency of the liquid crystal display 5 is returned to the original frequency. When the liquid crystal display is not viewed in this manner, the current consumption of the device 1 can be reduced by lowering the frame frequency of the liquid crystal display 5, and the operating life of the device 1 can be extended.

Next, the frame frequency switching operation in the device 1 having such a configuration will be described with reference to the flowchart shown in FIG. Note that the control program for executing this processing is stored in the memory 3, and the MPU 2
It is executed under the control of.

Now, it is assumed that the frame frequency of the device 1 is set to 70 Hz in order to suppress power consumption. In this state, when the operator takes the device 1 outdoors under the sunlight, the brightness around the device is higher than indoors, so that the display becomes less visible than when the device is used indoors. Then, the operator turns on the switching key 4 a provided on the input device 4.

When the switching key 4a is turned on (Y in step S1), the MPU 2 controls the clock generator 7, and changes the frequency of the clock signal supplied to the display controller 6 to the frame frequency up to that time. The frequency is increased from the corresponding frequency to 140 Hz (step S2). Here, the frame frequency of the liquid crystal display 5 is increased by 1 by increasing the frequency of the clock signal.
By raising the frequency to 40 Hz and performing liquid crystal display at this frame frequency (step S3), high-contrast display becomes possible, and the display becomes easy to see.

On the other hand, this high-contrast liquid crystal display
The operation is performed until the switching key 4a is turned off (step S4). When the switching key 4a is turned off (Y in step S4), the MPU 2 reduces the frequency of the clock signal from 140 Hz to a frequency corresponding to 70 Hz (step S5). Here, by returning the frame frequency of the liquid crystal display 5 to the original 70 Hz and performing the liquid crystal display (step 6), the current consumption of the device 1 can be reduced.

By the way, in the above description, the switching key 4 is used to switch the frame frequency of the liquid crystal display 5.
Although the description has been given of the case where the operation is performed by the manual operation of a, the present invention is not limited to this, and the switching of the frame frequency may be performed by the optical sensor.

Next, a description will be given of a second embodiment of the present invention in which the switching of the frame frequency is performed by the optical sensor.

FIG. 3 is a block diagram showing the configuration of the device according to the present embodiment. In the figure, the same reference numerals as those in FIG. 1 indicate the same parts.

An optical sensor 8 is installed on the surface of the device 1 near the liquid crystal display 5. Here, the optical sensor 8 always detects the luminance around the device 1 and inputs a detection signal to the MPU 1 when detecting that the luminance has a certain value or more.

Here, when the detection signal is input from the optical sensor 8, the MPU 1 controls the clock generator 7 to increase the frequency of the clock signal and to change the frame frequency of the liquid crystal display from a predetermined frequency (70 Hz) to another frequency. I am trying to raise it. Note that the frame frequency at this time is set in advance in the control program by, for example, 140 times the initial value.
A value determined as Hz may be used, or a program may be programmed so that it can be input from an input device during operation.

On the other hand, when the brightness drops below a certain value,
The detection signal from the optical sensor 8 is not input, and the MPU
Reference numeral 1 indicates that the frame frequency of the liquid crystal display 5 is returned to the original value, and the liquid crystal display is performed.

By providing the optical sensor 8 near the liquid crystal display 5 as described above, and when the optical sensor 8 detects a luminance equal to or more than a certain value, the frame frequency of the liquid crystal display 5 is increased. The liquid crystal display can be easily viewed even in an extremely bright place such as outdoors under sunlight.
Further, the operability of the device 1 can be improved.

Next, the frame frequency switching operation in the device 1 having such a configuration will be described with reference to the flowchart shown in FIG. As in the first embodiment, a control program for executing this process is stored in the memory 3 and is executed under the control of the microprocessor 2.

Now, it is assumed that the frame frequency of the device 1 is set to 70 Hz in order to suppress power consumption. In this state, when the operator takes the device 1 outdoors under the sunlight, the brightness around the device is higher than indoors, so that the display becomes less visible than when the device is used indoors. Here, when the luminance around the device becomes a certain value or more, the optical sensor 8 which constantly detects the luminance around the device 1 detects this and outputs a detection signal to the MPU 2.

When the detection signal from the optical sensor 8 is input (Y in step S1), the MPU 2 controls the clock generator 7 to change the frequency of the clock signal to be supplied to the display controller 6 to the previous frame. The frequency corresponding to the frequency is increased to a frequency corresponding to 140 Hz (step S2). Here, by increasing the frequency of the clock signal to increase the frame frequency of the liquid crystal display 5 to 140 Hz and performing liquid crystal display at this frame frequency (step S3), high-contrast display becomes possible. Is easier to see.

On the other hand, this high-contrast liquid crystal display
The process is performed until the luminance falls below a certain value and the detection signal from the optical sensor 8 disappears (step S4). When the luminance falls below a certain value and the detection signal from the optical sensor 8 disappears (Y in step S4), the MPU 2
Reduces the frequency of the clock signal from 140 Hz to a frequency corresponding to 70 Hz (step S5). Here, the frame frequency of the liquid crystal display 5 is set to the original 70 Hz.
The current consumption of the device 1 can be reduced by performing the liquid crystal display by returning to (Step 6).

[0032]

As described above, according to the present invention, the frame frequency can be switched in accordance with the switching instruction. Therefore, when the portable electronic device is used outdoors in a place where the peripheral luminance is high such as under the sunlight, etc. By increasing the number of frame traverses to increase the contrast of the liquid crystal display, the display can be easily viewed and the operability of the device can be improved. In addition, when the operator does not perform the operation for a while and does not look at the liquid crystal display, the current consumption of the device can be reduced by reducing the frame circulation number, and the operating life of the device can be extended.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a portable electronic device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of switching the frame frequency of the portable electronic device according to the embodiment.

FIG. 3 is an exemplary block diagram showing a configuration of a portable electronic device according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of switching the frame frequency of the portable electronic device according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Portable electronic device 2 Microprocessor 3 Memory 4 Input device 4a Switching key 5 Liquid crystal display 6 Display controller 7 Clock generator 8 Optical sensor

Claims (4)

[Claims] 1. A portable electronic device having a liquid crystal display, comprising: a scanning signal supply unit configured to supply a scanning signal corresponding to a frame frequency to the liquid crystal display; and the frame frequency is changed from a predetermined frequency to another frequency. Frame frequency switching instructing means for selectively instructing switching, clock supplying means for supplying a clock signal having a frequency corresponding to a predetermined frame frequency or another frame frequency to the scanning signal supplying means, and frame frequency switching instructing means Frame frequency control means for controlling the clock supply means to supply a clock signal having a frequency corresponding to the predetermined frame frequency or another frame frequency to the scan signal supply means in response to a frame frequency switching instruction by A portable electronic device characterized by the above-mentioned. 2. The portable electronic device according to claim 1, wherein said frame frequency switching instruction means is configured to issue a switching instruction by manual operation. 3. The portable electronic device according to claim 1, wherein said frame frequency switching instruction means is configured to issue a switching instruction in accordance with luminance around said liquid crystal display. 4. The portable electronic device according to claim 3, wherein said frame frequency switching instruction means comprises an optical sensor for detecting luminance around said liquid crystal display.