JP3245856B2 - Portable information terminal and display power control method - Google Patents

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, and more particularly, to a portable information terminal capable of reducing power consumption by display control.

[0002]

2. Description of the Related Art Electronic organizers and PDAs (Personal Digita)
l Assistance) is becoming popular. Generally, a liquid crystal display device (Liquid Crystal Device, LCD) is adopted as a display device of a portable information terminal.
A portable information terminal is required to display a large amount of display data in full color. In this full-color display processing, the amount of power consumed cannot be ignored.

As a known technique related to the present invention, Japanese Patent Laid-Open Publication No. Hei 6-186942 discloses a technique relating to a display device for the purpose of continuously operating a device driven by a battery for a long time. This display device reduces the number of accesses to the VRAM, the load on the display control system, and the power consumption of the display control system.

[0004] Japanese Patent Application Laid-Open No. 9-81885 discloses a technique relating to a portable information recording / reproducing apparatus for the purpose of effectively utilizing the navigation information of a vehicle-mounted navigation apparatus. This portable information recording / reproducing device facilitates the use of navigation information outside the vehicle.

Further, Japanese Patent Application Laid-Open No. 9-214860 discloses a technique relating to an electronic apparatus having a display controller having a plurality of screen modes. With this electronic device, the power consumption of the video memory used by the display controller is reduced.

FIG. 3 shows a conventional portable information terminal.
The portable information terminal includes a display device 201, a common display drive unit 203, a segment display drive unit 205, a display control unit 207, a main control unit 209, and an external display memory 211.
, A program memory 213, a main memory 215 and a keyboard 217.

[0007] The program memory 213 stores a plurality of application programs and display data (control panel and display panel) associated therewith. Main memory 215
Stores a plurality of display data (image data or character data).

The main control unit 209 refers to the program memory 213 or the main memory 215 based on a display command (not shown) input via the keyboard 217.
The main control unit 209 reads out the display data corresponding to the data address and stores it in the external display memory 211. Further, the main control unit 209 issues a display control command to the display control unit 207.

The display control unit 207 reads out display data stored in the external display memory 211 in response to a display control command, and displays display data (common display driving unit 20).
3 and the segment display driving unit 205) to display the read display data on the display device 201 in a time-division manner.

In a display system of a conventional portable terminal, particularly a portable terminal capable of color display, the amount of display data is enormous. Therefore, it is difficult to provide a display driving integrated circuit with a display storage means corresponding to an enormous amount of data. The display control unit 207 also controls the external display memory 21.
The display driving means is controlled while constantly reading out the display data stored in 1.

The power consumption due to the constant operation of the display control unit 207 and the power consumption due to the constant transfer of display data from the external display memory 211 to the display driving means are extremely large. In particular, a battery-operated portable information terminal has a short battery life, and thus there is a concern about continuous use time.

When a large-capacity battery is used in consideration of power consumption, the terminal becomes heavy. On the other hand, when the external display memory is provided in the integrated circuit of the display drive unit to reduce the power consumption, the cost increases.

There is a need for a portable information terminal that performs display processing with less power consumption. Further, in this portable information terminal, it is desirable that the storage location of the display data is set based on the attribute of the display data so that the time-series read / transfer processing of the display data is reduced.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide a portable information terminal in which the amount of power consumption in display processing is reduced. Another object of the present invention is to provide a portable information terminal in which the storage location of the display data is set efficiently based on the attribute of the display data so that the time-series read / transfer processing of the display data is reduced. To provide.

[0015]

The portable information terminal of the present invention (see FIG. 1) has a display device (1) for displaying display data.
01) and storage means (1) for storing a plurality of display data.
15, 117), first storage means (111) for storing display data corresponding to the first attribute, and second storage means (111) for storing display data corresponding to the second attribute. 113) and selecting a storage destination from the first and second storage means based on the attribute of the display data corresponding to the display request and responding to the display request stored in the storage means (115, 117). Main control means (109) for storing display data to be stored in a selected storage location and generating a control signal;
A second storage means (113) for displaying display data corresponding to a display request from the selected storage location on the display device (101) based on the control signal;
And a driving means (103).

The display control / driving means (103)
Reads out and transfers display data requested to be displayed in response to a control signal generated when the attribute of display data corresponding to the display request is the first attribute; In response to a control signal generated when the attribute of the data is the second attribute, a display control means (107) for stopping the operation and a second storage means (113) are provided. When the attribute of the corresponding display data is the first attribute, the display device (101) is driven to display the transferred display data, and the attribute of the display data corresponding to the display request is the second attribute. The display device is driven in response to the control signal generated when the second storage means (1
It is preferable to include display driving means (121, 123) for displaying display data corresponding to the display request stored in 13).

Further, the display data corresponding to the first attribute is preferably high gradation or color display data, and the display data corresponding to the second attribute is preferably low gradation or monochrome display data. .

Further, storage means (115, 117),
Each of the first storage unit (111), the main control unit (109), the display control unit (107), and the display drive unit (105) is preferably connected to each other by a bus line.

With the portable information terminal having the above configuration, a display process in which power consumption is reduced as compared with the related art is realized.

According to the display power control method for a portable information terminal of the present invention, in response to a display request input from the outside, a storage destination is selected based on an attribute of display data corresponding to the display request; The display data corresponding to the request is stored in the selected storage destination via the bus line, and the display signal is selectively executed based on the attribute of the display data corresponding to the display request. It is performed by the thing. Here, the selected storage destination is a first storage unit (111) for storing display data corresponding to the first attribute.
And any of the second storage means (113) for storing display data corresponding to the second attribute.

With respect to the above processing, selectively executing the display processing means that the attribute of the display data corresponding to the display request is the first.
In response to a control signal generated when the attribute is the attribute of the display device, the display data corresponding to the display request stored in the first storage means is transferred via the bus line, and the display device (10
1) to display the transferred display data.

In addition, the selective execution of the display processing means that the display device (10) responds to a control signal generated when the attribute of the display data corresponding to the display request is the second attribute.
1) to automatically display display data corresponding to the display request stored in the second storage means.

The display data corresponding to the first attribute is:
The display data that is high gradation or color display data and that corresponds to the second attribute is preferably low gradation or monochrome display data.

Incidentally, the reference numerals (numbers) assigned to the above constituent elements
Is for facilitating the understanding of the present invention, and should not be taken into account in interpreting the scope of the claims.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a portable information terminal and a power control method according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a block diagram of a portable information terminal according to an embodiment of the present invention.

The portable information terminal includes a display device 101, a display control unit 107, a main control unit 109, an external display memory 1
11, the program memory 115, and the main memory 117
, A keyboard 119, a common display driver 121 and a segment display driver 123.

The display control unit 107, the main control unit 109, the external display memory 111, the program memory 115, the main memory 117, the keyboard 119, and the display drive unit 105 (segment display drive unit 123) are provided with a data bus or a control bus (hereinafter, referred to as a control bus). A, B, C,
D, E, F).

The display device 101 displays display data. The display device 101 can perform color display. In the present embodiment, a liquid crystal display (LCD) is employed, but the present invention is not limited to this. Main control unit 109
Is composed of a microcomputer. Further, the main control unit 109 implements processing according to a program for implementing the functions of the portable information terminal.

A display request from a user is input externally. In the present embodiment, only the keyboard 119 is shown, but this does not limit the present invention. For example, a “mouse” connected directly or indirectly to the main control unit 109 and directly instructing (displaying request) on the screen of the display device 101 as an external input means is also applied to the present invention.

The program memory 115 stores a plurality of display data. The program memory 115 stores a plurality of display data corresponding to the first attribute. In the present embodiment, the display data corresponding to the first attribute corresponds to high gradation or color display data. The program memory 115 stores a plurality of application programs and associated display data (display panel and control panel) corresponding to addresses.

The main memory 117 stores a plurality of display data. The main memory 117 stores a plurality of display data having the first attribute and a plurality of display data corresponding to the second attribute. In the present embodiment, the display data corresponding to the second attribute corresponds to low gradation or monochrome display data. The main memory 117 stores a plurality of display data (image data or character data) corresponding to addresses.

The common display drive section 121 and the segment display drive section 123 form a display drive section 105. Further, the common display drive unit 121, the segment display drive unit 123, and the display control unit 107 include the display control / drive unit 10.
Form 3

The common display driver 121 performs a time-division display operation. The segment display driving unit 123 drives the display device 101 to display the display data transferred from the external display memory 111 or the display data stored in the display memory 113.

The segment display driving section 123 has a display memory 113 therein. External display memory 111
Stores display data corresponding to the first attribute. The display memory 113 stores display data corresponding to the second attribute.

The main control unit 109 selects a storage destination from the external display memory 111 and the display memory 113 based on the attribute of the display data corresponding to the display request. Main control unit 1
09 is the program memory 115 or the main memory 11
The display data corresponding to the display request stored in 7 is stored in the selected storage location. At this time, the main control unit 109 generates a control signal (not shown).

The display control / drive unit 103 includes the main control unit 10
9 on the display device 101 based on the control signal from the selected storage location. The control signal is generated based on an attribute of the display data. Further, details of the display control / drive unit 103 will be described below.

Display control section 107 reads and transfers the display data requested to be displayed in response to a control signal generated when the attribute of the display data corresponding to the display request is the first attribute. Further, the display control unit 107 stops the operation of the display control unit 107 itself in response to a control signal generated when the attribute of the display data corresponding to the display request is the second attribute.

The display drive unit 105 drives the display device 101 in response to a control signal generated when the attribute of the display data corresponding to the display request is the first attribute, and displays the transferred display data. Display. Also, the display drive unit 108
Drives the display device 101 to display the display data stored in the display memory 113 in response to a control signal generated when the attribute of the display data corresponding to the display request is the second attribute.

FIG. 2 is a flowchart showing a power control method for a portable information terminal according to the present embodiment.
First, a display request is externally input by the user via the keyboard 119 (step S101, Yes). The display request specifies an application program to be used and data to be displayed.

The main control unit 109 generates an address of the display data in response to the display request. The main control unit 109 refers to the program memory 115 and the main memory 117 based on the generated address. The main control unit 109 determines whether the attribute of the display data corresponding to the display request is display data (monochrome or low gradation data) corresponding to the second attribute (step S102).

Next, the main control unit 109 proceeds to step S10
The storage destination is selected from the external display memory 111 and the display memory 113 based on the determination in step 2. Main control unit 10
9 indicates that the main memory 1 has determined that the attribute of the display data requested to be displayed is the display data corresponding to the second attribute.
The display data requested to be displayed is read from the memory 17.

The main control unit 109 transfers the read display data via the bus line and stores it in the display memory 113 (step S103). At the same time as step S103, the main control unit 109 generates a control signal to turn on the display drive unit 105 (segment drive unit 123) to start (step S104), and the display control unit 10
7 to "OFF" to stop the operation (step S10
5).

The above processing (steps S101 to S10)
By the process of 5), the display control unit 107 is released from the operation of the data read monitoring / transfer process. Therefore, power consumption in the display processing is reduced. In this case, the display data stored in the display memory 113 is transmitted to the display control unit 10.
7, the display is automatically displayed on the display device 101 by the segment display driving unit 123 without the intervention of the instruction.

After step S105, the main control unit 109
Stops the operation of the display drive unit 105 (segment display drive unit 123) in response to an instruction to stop display by an external input (step S106) (step S107).

In step S102, the main control unit 10
9 determines that the attribute of the display data requested to be displayed is not the display data corresponding to the second attribute, and reads the requested display data stored in the program memory 115 or the main memory 117.

The main control unit 109 includes the program memory 11
5, or display data corresponding to the display request stored in the main memory 117 is stored in the external display memory 111 via the bus line. At this time, the main control unit 109 generates a control signal and turns on the display control unit 107 to activate (step S108).

The display control unit 107 includes the external display memory 11
The display data requested to be displayed stored in No. 1 is read out so as to be displayed in a time-division manner, and a bus line (eg, bus line A)
(Step S109).

The display control unit 107 continues the transfer process while the display data is displayed on the display device 101. The display drive unit 105 drives the display device 101 to display the transferred display data on the display device 101 based on an instruction from the display control unit 107.

After step S109, the main control unit 109
Responds to an instruction to stop display by an external input (step S110), and causes the display drive unit 105 and the display control unit 107
Is stopped (step S111).

In the portable information terminal according to the present embodiment, when displaying monochrome display data such as character data, the display data is stored in storage means built in the display drive unit. The stored display data is automatically displayed only by the display driving unit 105 (segment display driving unit 123) and the display device 101. Therefore, power consumption is reduced, and further,
Long-term use and lighter terminals are realized.

[0051]

The portable information terminal according to the present invention reduces the power consumption in the display processing. This is based on the fact that the storage locations of the display data are set to be efficiently distributed based on the attributes of the display data.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a portable information terminal according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the portable information terminal according to the embodiment of the present invention.

FIG. 3 is a block diagram for explaining a conventional portable information terminal.

[Explanation of symbols]

 101, 201: display device 103: display control / drive unit 105: display drive unit 107, 207: display control unit 109, 209: main control unit 111, 211: external display memory 113: display memory 115, 213: program memory 117 , 215: Main memory 119, 217: Keyboard 121, 203: Common display driver 123, 205: Segment display driver A, B, C, D, E, F: Bus line

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FIG09G 3/20 680 G09G 3/20 680S 680T H04Q 7/38 H04B 7/26 109M (58) Investigated field (Int. Cl. ⁷ G09G 3/00-3/38 G09G 5/00-5/42 H04Q 7/38

Claims (8)

(57) [Claims] 1. A display device for displaying display data, a storage unit for storing a plurality of the display data, a first storage unit for storing display data corresponding to a first attribute, A second storage unit for storing display data corresponding to a second attribute; and an attribute of the display data corresponding to a display request.
A storage destination is selected from the first and second storage units, the display data corresponding to the display request stored in the storage unit is stored in the selected storage destination, and a control signal is generated. And a second control unit for displaying the display data corresponding to the display request from the selected storage destination on the display device based on the control signal. And a display control / driving means. 2. The display control / drive unit, wherein the display request is issued in response to the control signal generated when the attribute of the display data corresponding to the display request is the first attribute. Display control for reading and transferring read display data and stopping operation in response to the control signal generated when the attribute of the display data corresponding to the display request is the second attribute Means for displaying the transferred display data by driving the display device when the attribute of the display data corresponding to the display request is the first attribute. In response to the control signal generated when the attribute of the display data corresponding to the display request is the second attribute, the display device is driven and stored in the second storage unit. Respond to the display request Portable information terminal according to claim 1, wherein a and a display driving means for displaying the display data. 3. The display data corresponding to the first attribute is the high gradation or color display data, and the display data corresponding to the second attribute is the low gradation or monochrome display data. 2. The method according to claim 1, wherein
Or the mobile information terminal according to 2. 4. The apparatus according to claim 1, wherein said storage means, said first storage means, said main control means and said display control / drive means are connected to each other by a bus line. Mobile information terminal. 5. A step of selecting a storage destination based on an attribute of display data corresponding to the display request in response to a display request input from outside, wherein the selected storage destination is a first storage destination. One of a first storage unit for storing the display data corresponding to an attribute, and a second storage unit for storing the display data corresponding to a second attribute, the storage unit corresponding to the display request Storing the display data at the selected storage location via a bus line, and generating a control signal based on the attribute of the display data corresponding to the display request to selectively perform display processing. Performing a display power control of the portable information terminal. 6. The method according to claim 1, wherein the step of selectively performing the display process comprises: responding to the control signal generated when the attribute of the display data corresponding to the display request is the first attribute. Transferring the display data corresponding to the display request stored in the first storage unit via the bus line; and driving a display device to display the transferred display data. The display power control method for a portable information terminal according to claim 5, wherein the display power control method includes: 7. The method according to claim 7, wherein the step of selectively performing the display processing comprises: responding to the control signal generated when the attribute of the display data corresponding to the display request is the second attribute. Driving the display device and automatically displaying the display data corresponding to the display request stored in the second storage means. 6. The display of the portable information terminal according to claim 5, further comprising: Power control method. 8. The display data corresponding to the first attribute is high gradation or color display data, and the display data corresponding to the second attribute is low gradation or monochrome display data. 6. The method according to claim 5, wherein
The display power control method of the portable information terminal described in the above.