JPH10319942A - Picture display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a switching time of a screen by increasing an updating time of data for a picture memory of a picture display device. SOLUTION: This device is constituted with a display data making section 101, a display data access section 102 outputting a control signal for accessing display data, a switcher 103 including two changeover switches, a picture memory section 104 in which data outputted in an image region is stored, a non- picture memory section 107 in which data read out in a non-image region is stored, a D/A converter 105, and a display section 106 to which an output of the D/A converter is supplied. In a period in which an image region is scanned, contents of the picture memory section 104 are read out to the D/A converter 105 through a contact (b) and a contact (c) of the switcher 103, next, in a scanning period of a non-image region, data stored in the non-picture memory 107 is read out to the D/A converter 105 through a contact (d) of the switcher 103, while can be accessed the picture memory section 104 through a contact (a).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly to an image display device capable of displaying graphic information and character information displayed on a monitor of a computer or the like at high speed on a display screen. .

[0002]

2. Description of the Related Art Generally, an image display device such as a computer has a single-port memory for storing a display image.
By reading out, one display image is formed.

[0003] An outline of a display control section forming such an image display device will be described below with reference to FIG. The display controller 10 is a display data generator 1 for forming display data.
And a display data access unit 2 for accessing the image display data formed by the display data creation unit 1 at a predetermined timing, storing the data in the image memory 4, and reading out the data in the effective image area. The data stored in the image memory 4 is supplied to the D / A converter 5 via the switch 3 at a predetermined timing, and the image signal converted into an analog signal is converted to a display unit 6 for forming a display screen. And an image is displayed.

Reference numeral 7 denotes a display controller comprising a microcomputer for controlling data transfer, data reading, writing and the like in the display control unit 10. The timing at which these command signals are output is output from a timing generation circuit 8. This is performed based on the synchronization signal to be performed.
That is, as shown in FIG. 4, the display controller 7 scans the range of the vertical range v2 indicating the area of the effective screen and the range of the horizontal direction H2 on the screen of the display unit 6 and the effective screen period. Then, data is read from the image memory 4 and the read data is supplied to the display unit 6 via the switch 3 and the A / D converter 5 connected to the contact b to perform image display and perform vertical display. In the non-effective screen area of the screen which is set to V1 and V3 in the horizontal direction and set to H1 and H3 in the horizontal direction, the switch 3 is switched to the contact a side to be connected to the display data access unit 2.

At the timing of scanning the non-effective screen area, the image data to be displayed next is controlled to be fetched from the display data creation unit 1 into the image memory 4. During the period of the non-effective screen area, the display controller 7 controls so as to blank the output of the D / A converter 5.

[0006]

As described above, in the case of the conventional image display device, the period during which the image memory 4 is accessed without disturbing the display screen or without muting the display screen is limited to the display unit. 6 is limited to the period in which the scanning line scans the non-effective screen area. Since the display data is updated during this period, it is difficult to rewrite a large amount of data at high speed. There is a problem that it takes time to update the file.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a display data creating unit, an access control unit for accessing an image memory, and storing image data. A single-port image memory, a means for reading display data from the image memory, a D / A conversion means for converting the read display data into an analog signal, a timing generating means for generating a timing for reading the display data, In an image display device provided with control means for controlling writing and reading, a display area is divided into an image area and a non-image area so that reading and writing of image data can be managed.

[0008]

According to the present invention, the image display area is divided into the image display area as the "image data read area" and the non-image display area as the "non-image memory read area". Then
By utilizing the screen scanning period of the non-image display area, writing and reading to the image memory can be performed. Also, if the image display area is divided into an image display area and a non-image display area and managed so that the divided area can be programmably changed according to the content of the display image, the image display area can be changed even with the same memory capacity. In a screen with a small width, the scanning period of the non-image display area is used,
A large amount of update data can be acquired, and the display screen can be switched quickly without disturbing the display screen.

[0009]

FIG. 1 is a block diagram for explaining an embodiment of an image display device according to the present invention. FIG. 2 is a diagram showing an image display area and a non-image display area set according to the present invention. Is shown on the screen for explaining the operation. First,
The outline of the image setting of the present invention will be described with reference to FIG. The screen areas V11 and V15 in the vertical direction and H11 and H15 in the horizontal direction are non-effective screen areas where there is no image data to be displayed. You can decide.

The areas defined as V12 and V14 in the vertical direction and H12 and H14 in the horizontal direction are defined as a non-image display area 120A in which image data exists in the non-image memory area. The content of the image in the area 120A can be, for example, a cursor image stored in a small-capacity memory, or a fixed color set in a register or the like. Further, when the non-image display area 120A is divided into a plurality of parts, a plurality of fixed colors set in each register can be used. An area represented by V13 in the vertical direction and H13 in the horizontal direction is an image display area 120B in which an image is present in the image memory area, and image data in this area is frequently transferred, written, and read. The display controller operates to update the image.

Next, a main block diagram of the front image display apparatus of the present invention will be described with reference to FIG. In this figure, 100
Denotes a display control unit. The display control unit 100 includes a display data generation unit 101 and image display data formed by the display data generation unit 101 at predetermined times in the image memory 1.
04, a display data access unit 102 for reading from the image memory 104, a switcher 103 including two changeover switches, an image memory unit 104 for storing data mainly output in the image display area 120B, Non-image memory unit 10 in which data read in non-image display area 120A is stored
7. A D / A converter 105 for converting a digital signal into an analog signal, and a display unit 106 to which the output of the D / A converter 105 is supplied as an image signal. The image memory unit 104 is a single-port DRAM, and the non-image memory unit 107 is a small-capacity SR.
It can be composed of an AM or a register.

Reference numeral 108 denotes a display controller for controlling the display control unit 100. Display data is created based on command data output from the display controller 108, and the created image data is generated at a predetermined timing. The data read into the image memory unit 104 and the data read through the switcher 103 are supplied to the D / A converter 105. 1
Reference numeral 09 denotes a timing generation circuit which supplies a predetermined clock signal and a control signal in synchronization with the effective screen area and the non-effective screen area shown in FIG.

In this block diagram, for example, while the display controller 108 scans the image display area 12B (hereinafter, also simply referred to as an image area), the contents of the image memory section 104 are switched to the Sw1 b contact of the switcher 103 and It is controlled to be readable to the D / A converter 105 via the c contact of SW2, and the display unit 10
6 can be displayed.

Next, a non-image display area 120A (hereinafter referred to as a non-image display area 120A)
During the scanning period of the non-image area (also simply referred to as a non-image area), the data of the non-image information stored in the non-image memory unit 107 is read out to the D / A converter 105 via the contact d of the switch SW2 of the switcher 103, and is displayed. At the same time, the contents of the image memory unit 104 are connected to the display data access unit 102 via the contact point a of the switch SW1 of the switcher 103, and the access to the image memory 104 is enabled.

Further, at the scan timing of the non-effective image area of the display unit 106, the contents of the image memory unit 104 are connected to the display data access unit 102 via the contact a of SW1 of the switcher 103, and the access to the image memory unit 104 Is possible. That is, in the non-effective screen area, the data in the image memory can be updated with the image data formed by the display data creation unit 101 and the like. At this time, the display controller 108 is controlled to output a blanking signal to the output side of the D / A converter.

In the embodiment of the present invention, during the period of the image area as described above, the display data access unit 102
Is controlled so that access to the image memory unit 104 is disabled, but the display data access unit 102 can access the image memory unit 104 during the non-image area period and the non-effective screen area period. In this period, the image memory unit 104 can be refreshed, data can be updated, and the like.

Therefore, in the case of the conventional image display device, the access to the image memory can be performed only during the period of the non-effective screen area. Therefore, there is a margin in the timing, and it is possible to reduce the image switching time required for a high-density display screen or the like.

Furthermore, since the image data is supplied from the non-image memory unit 107 to the display unit 106 even in the non-image area period, the problem that a part of the display is lost and the sense of incongruity is caused is solved. I can do it. Note that the data stored in the non-image memory unit 107 may be cursor data, icon data, and the like, which are not frequently rewritten, or may be background color data of a display screen.

When the display data is smaller than the effective screen area, the time for accessing the image memory unit 104 can be extended by setting the non-image area large as described above. Update time can be reduced. However, when the display data has the same size as the effective screen area, the non-image area cannot be set, but at least the memory is accessed during the period of the non-effective image area as in the related art. .

In the case of the present invention, the setting of the non-image area can be programmably changed by the display controller 108 in accordance with the size of the image area displayed in the effective screen area while the data is displayed in the effective screen area. Display the updated image data as the image display area,
For the unupdated portion, the contents of the non-image memory unit 107 are displayed as a non-image display area.

In FIG. 2, the areas indicated by V12, V13, V14 and H12, H13, H14 are effective image areas and have a fixed period. Therefore, in this area, the range of V13 is set by counting the scanning lines, and the range of H13 is set by counting the number of dots in the horizontal direction. In FIG. 2, a section where V13 and H13 are at the high level is an image area, and an effective image area excluding this image area is a non-image area. Such a setting is effective during the period of the non-effective image area.
V13 and H13 can be changed.

[0022]

As described above, according to the image display apparatus of the present invention, by setting the non-image area together with the non-effective image area on the screen, the access timing to the memory can be increased. This has the effect that writing to and reading from the image memory can be performed at high speed as needed without disturbing the display screen and without muting the display scene.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of an image display device of the present invention.

FIG. 2 is an explanatory diagram of an image display area according to the present invention.

FIG. 3 is a block diagram illustrating an outline of a conventional image display device.

FIG. 4 is an explanatory diagram of a conventional effective image area and a non-effective image area.

[Explanation of symbols]

101 display data creation unit, 102 display data access unit, 103 switcher, 104 image memory unit, 1
06 display unit, 107 non-image memory unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Matsushita 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Yousuke Yamamoto 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (3)

[Claims] 1. A display data accessing means for accessing display data creating means and an image memory, a single port image memory for storing image data, and a D for converting display data read from the image memory into an analog signal. An image for displaying a signal converted by the D / A conversion means on a display, comprising: a / A conversion means; a timing generation means for generating read timing of the display data; and a control means for controlling writing and reading of the display data. An image display device, wherein a display area is divided into an image display area and a non-image display area to write image data. 2. The image display device according to claim 1, wherein each of the image display area and the non-image display area is programmable. 3. The image display device according to claim 1, wherein said control means performs writing and reading to and from the image memory during a period other than accessing the image display area.