JP2880964B2 - Display area switching system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display area switching system, and more particularly to a display area switching system for displaying image data having different resolutions from an image processing unit of a computer device on a screen of a display device having a variable resolution function. About the system.

[0002]

2. Description of the Related Art Conventionally, the number of pixels (number of vertical and horizontal dots or resolution) that can be displayed in the range of a physical screen of a display device is often fixed, and display data of a wide range equal to or larger than the number of pixels of the display device is used. When displaying on a screen, for example,
As shown in Japanese Patent Publication No. 273290, the display data that has been bit-mapped is compressed and converted into bit-mapped data having the same number of pixels as the number of pixels of the display device. Is displayed.

FIG. 6 is a block diagram described in the above publication. The display data generated in the virtual screen storage area 54 by the application software is transferred to the display content control device 53 in fixed block units, and the bitmap image corresponding to the compression ratio specified by the display data compression / decompression control device 55 is displayed. After undergoing the compression process, it is re-expanded in the display screen storage area 52 and displayed on the actual display screen 51. This method has a drawback in that the amount of information inherent in the display data (such as the number of pixels) is thinned out and displayed by the compression processing, so that the entire amount of information inherent in the display data cannot be displayed.

In recent years, with the development of image processing technology, it has become possible to easily realize high-resolution image processing at various resolutions, and one computer apparatus can switch and use image processing of a plurality of resolutions. doing.
On the other hand, display devices having a variable resolution function have also been developed, and an environment in which various image processing can be realized by combining these display devices is being prepared. Thus, when displaying display data of a display capacity of a fixed resolution display device or more as in the known example described above on a screen, a high resolution display device having a resolution variable function is used, and a wide range of display data is displayed. At the time of display, by switching to a higher resolution than normal, all the display data can be displayed on the screen without losing the information amount.
However, in the case of using a combination of the image processing function of a plurality of resolutions and a display device having a variable resolution function, at present, the user intervenes on the display device side and the computer device side to set and match the conditions. There is a need.

[0005]

As described above, when the display data is compressed to display the display data having the display capability or more on the screen by the display device having the fixed resolution, the amount of information inherent in the display data is reduced. There is a drawback that can not be displayed all. On the other hand, if the resolution is switched using a display device having a high-resolution variable resolution function, a wide range of display data can be displayed on the screen without losing the information amount. At this time, it is desirable to select the resolution without manual intervention according to the range of the display data.
Even when image processing of various resolutions is possible, it is desired that the display resolution can be automatically selected according to the state of the display data to be created.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image processing section of a computer device which is used in combination with a computer device capable of image processing at a plurality of resolutions or changing a display range and a display device having a variable resolution function. An object of the present invention is to provide a display area switching system capable of automatically selecting a resolution in accordance with supplied display data.

[0007]

According to a first aspect of the present invention, there is provided a display area switching system comprising: a video memory capable of storing display data corresponding to a maximum display capability of a display device having a variable resolution function; Storage area detecting means for detecting a storage area of the display data written in the video memory, and a display area switching function for reading out the display data stored in the specified display area from the video memory, A display circuit for transmitting a display input signal having a corresponding resolution, display capability storage means for storing display capability information indicating a type and range of a display area selectable by the display circuit, and the storage area detection means A storage area for display data is compared with display capability information stored in the display capability storage unit to determine a type of display region to be selected. A comparison unit that is configured to include a display area switching means for performing switching of the display area of the display circuit based on the comparison result of the comparing means.

According to a second aspect of the present invention, in the display area switching system according to the first aspect, the display capacity storage means is constituted by a volatile memory, and the display capacity storage means is transferred from an external storage device or the like to the display capacity storage means at startup. A display capability reading means for reading display capability information is provided.

A display area switching system according to a third aspect of the present invention is the display area switching system according to the first aspect, wherein the display capability storage means is a nonvolatile semiconductor memory built in the display circuit.

According to a fourth aspect of the present invention, in the display area switching system according to the first aspect, the storage area detection means writes the video data to the video memory when a resolution or a display range is changed from an image processing unit of a computer device. The storage area is detected by monitoring the write address of the display data to be stored.

A display area switching system according to a fifth aspect of the present invention is the display area switching system according to the first aspect, wherein the storage area detecting means sends display data transmitted from an image processing unit of a computer device when a resolution or a display range is changed. The storage area is determined based on the writing range notification signal.

[0012]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention.

As shown in FIG. 1, a display area switching system 1 according to the present embodiment has a display device 9 having a variable resolution function.
And an interface function for displaying display data generated by the image processing unit 10 on the display screen of the display device 9. The display area switching system 1 includes a video memory 2 that can store display data corresponding to the maximum display capability of the display device 9, a storage area detection unit 3 that detects a storage area of the display data written in the video memory 2, A display circuit 4 having an area switching function for reading display data stored in a specified display area of the video memory 2 and displaying the display data on the display device 9 at a corresponding resolution; and a display selectable by the display circuit 4 The display capacity storage means 5 storing the type and range of the area, and the storage area of the display data detected by the storage area detection means 3 and the display area range stored in the display capacity storage means 5 are compared and selected. Comparing means 6 for determining the type of display area to be displayed; display area switching means 7 for switching the display area to the display circuit 4 based on the comparison result of the comparing means 6; Is composed of a display capability reading means 8 reads the display capability information stored in the external storage device Temu startup the display capability storing means 5.

The video memory 2 is a volatile memory (RAM) having a storage capacity capable of storing display data of the number of vertical and horizontal dots corresponding to the maximum display capability (resolution) of the display device 9.
The image processing unit 10 has matrix-shaped X and Y addresses corresponding to the dot arrangement on the display screen, and writes display data of various resolutions and display ranges. FIG. 2 is an explanatory diagram showing the concept of the configuration of the video memory 2. The values of the maximum X address and the maximum Y address of the entire memory correspond to the number of vertical and horizontal dots of the maximum resolution of the display device 9, and the low resolution normal display is performed. The display data of the range is the origin (X and Y addresses are 0
Display areas A,
Are stored in display areas B.... Further, the display circuit 4 reads out display data stored in the range of the display area A, the display area B,... Corresponding to the selected resolution.

The storage area detecting means 3 monitors display data written from the image processing section 10 to the video memory 2, and performs image processing to clear the video memory 2 when the resolution or the display range is changed. When the memory reset signal output from the section 10 is detected, the maximum value of the write address (X and Y addresses) updated by the subsequent write signal is detected and passed to the comparing means 6.

The display circuit 4 is a circuit for outputting a display signal (input signal of the display device 9) having a function capable of coping with a plurality of types of display capabilities (resolutions) by switching, and a display set from the video memory 2. The display data stored in the display areas A, B,... Corresponding to the capabilities is read out at the display timing of the resolution, converted into a digital signal, converted into an analog video signal, and supplied to the display device 9 together with the synchronization signal.

The display capability storage means 5 is a storage area on a RAM for storing information on a plurality of types of display capabilities that can be supported by the display circuit 4, and stores display capability identifiers A, B to N as shown in FIG. Correspondingly, the number of horizontal dots and the number of vertical dots are stored. The display capability identifiers A, B,
N corresponds to the display area A, the display area B,..., The display area N of the video memory 2 in FIG.

The comparison means 6 compares the storage area of the display data detected by the storage area detection means 3 with the display capacity stored in the display capacity storage means 5 to determine the type of display capacity actually used. The display capacity information is read from the display capacity storage means 5 in ascending order of the number of vertical and horizontal dots, and is compared with the values of the maximum X address and the maximum Y address read by the storage area detection means 3 and written into the video memory 2. It is determined at which resolution the displayed data should be displayed.

The display area switching means 7 receives the display capability identifier determined by the comparing means 6, and switches so that the display circuit 4 operates with the display capability of the display capability identifier.

The display capability reading means 8 is for reading the display capability information of the display circuit 4 stored in an external storage device or the like in advance when the system is started, and writing the display capability information in the display capability storage means 5 on the RAM.

The display device 9 is a display device having a variable resolution function such as a multi-scan CRT monitor or a multi-scan liquid crystal display.
It operates with an analog input signal such as a GB separate signal system or a video signal system.

FIG. 4 is a flow chart of the switching operation of the embodiment shown in FIG. Hereinafter, the operation of the display area switching system of the present embodiment will be described with reference to the flowchart of FIG.

When the system is started, display capability information which can be displayed by the hardware function of the display circuit 4 is read from the external storage device by the display capability reading means 8, and
It is stored in the display capability storage means 5 (step S1). The storage area detecting means 3 monitors the presence or absence of a memory reset signal from the image processing unit 10 (step S2). Upon detecting the reset signal, the storage area detecting means 3 determines the maximum value of the write address of the display data to be subsequently written to the video memory 2. By detecting, the size of the storage area where the display data is written is detected (step S3). Upon receiving the address value detected by the storage area detecting means 3, the comparing means 6 reads out the display capability information of the minimum resolution stored in the display capability storing means 5 (step S4), and displays the display data written in the video memory 2. Is determined based on the number of vertical and horizontal dots in the display capability information (step S5). As a result of the judgment,
If the display cannot be performed, the display capability information of the next higher resolution is read out from the display capability storage means 5 (Step S).
6) Returning to step S5, this comparison operation is repeated until display capability information capable of displaying the written display data is detected.

When the display capability information which can be displayed is detected in step S5, the comparing means 6 passes the corresponding display capability identifier to the display area switching means 7 (step S7). The capability is switched to the state of the corresponding resolution (step S8). Display circuit 4
Is the video memory 2 corresponding to the switched display capability.
The display data in the corresponding display areas A, B,... Is read out at the display timing of the resolution, converted into an analog signal, and transmitted to the display device 9 together with a synchronization signal (step S9).

When the above-described steps S7 to S9 are completed and the switching of the display capability of the display circuit 4 (the display area of the video memory 2) is completed, the process returns to step S2. It waits until the range is changed and the display data is updated and written to the video memory 2 following the memory reset signal. When the use of the computer device is terminated without any change in the resolution or the display range (step S10), all the processes are terminated and the power is turned off, so that the display capability information in the display capability storage means 5 is also erased. Therefore, at the same time as the restart, the process is started from reading from the external storage device in step S1.

As described in detail above, the display area switching system 1 of the present embodiment automatically changes the display capability of the display circuit 4 according to the size of the storage area of the display data written in the video memory 2. To switch. That is, when the resolution or display range of the image to be displayed is changed, the storage area detecting means 3 detects the maximum value of the write address of the display data written from the image processing unit 10 to the video memory 2, and the comparing means 6 displays the display capacity. The resolution to be selected is determined by comparing the number of vertical and horizontal dots of each resolution stored in the storage means 5, and the display area switching means 7 executes switching in accordance with the determination.

By this switching, the display circuit 4 reads display data from the video memory 2 in the display areas A and B corresponding to the number of vertical and horizontal dots of the selected resolution.
The size of the storage area where the display data is actually written does not always match the display area. That is, when the display data written to the video memory 2 matches the resolution selectable by the display circuit 4, the display data storage area and the display area match, but the display data to be written is If the resolution is different from the selectable resolution, or if one or more normal display data is displayed by changing the display range, the storage area of the display data may not match the selectable display area. is there. In such a case, the smallest display area including the storage area is selected, and the display data is stored and displayed on one screen without impairing the information amount.

In the above-described embodiment, the display capability storing means is provided on the volatile RAM, and the display capability reading means reads the display capability information from the external storage device at the time of startup. EEPRO
If it is constituted by a nonvolatile semiconductor memory such as M, the display capability reading means becomes unnecessary and can be built in the display circuit. The storage area detecting means detects the storage area of the display data from the maximum value of the write address of the display data written to the video memory when the resolution or the display range is changed. It is also possible to transmit information on the number of vertical and horizontal dots of the display data to be written from the image processing unit when the image data is changed, and to receive and judge the information by the storage area detecting means.

The comparing means sequentially reads out the display capability information from the display capability storing means irrespective of the current setting state of the display circuit, and determines the resolution to be selected by comparing with the storage area detected by the storage area detecting means. The display area switching means performs the switching according to the determination. On the other hand, the display circuit outputs display capability information corresponding to the current setting state, and the comparing means determines whether or not display is possible with the current setting, and changes the setting downward or upward by one step. May be repeated to obtain the final setting state.

[0031]

As described above, the display area switching system of the present invention has a video memory capable of storing display data corresponding to the maximum display capability of a display device having a variable resolution function to be used, and a plurality of resolutions by switching. It has a display circuit that can be used correspondingly, and storage area detection means for detecting the size of the storage area of the display data written in the video memory, and when the resolution or display range of the displayed image is changed, the image is displayed. The setting of the display circuit is automatically changed in accordance with the storage area of the display data written from the processing unit to the video memory, and the display can be displayed on the display device at a resolution adapted to the display data. For this reason, it is possible to easily cope with the change of the resolution, and when the selectable resolution of the display circuit does not match the resolution of the display data to be displayed by the image processing unit of the computer device, or when the resolution is changed. Even when the display range is changed without performing the operation, the display data can be displayed within one screen without losing the information amount of the display data, which is effective in improving operability and display performance.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a configuration concept of a video memory in FIG. 1 and a display area.

FIG. 3 is an explanatory diagram showing storage contents of a display capability storage means of FIG. 1;

FIG. 4 is a flowchart showing the operation of the display area switching system of FIG. 1;

FIG. 5 is a block diagram showing an example of a conventional display control device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 display area switching system 2 video memory 3 storage area detecting means 4 display circuit 5 display capability storage means 6 comparing means 7 display area switching means 8 display capability reading means 9 display device 10 image processing unit 51 actual display screen 52 display screen storage area 53 display content control device 54 virtual screen storage area 55 display data compression / decompression control device

Claims (5)

(57) [Claims] 1. A video memory capable of storing display data corresponding to a maximum display capability of a display device having a variable resolution function, and a storage area of display data written into the video memory from an image processing unit of a computer device is detected. Storage area detection means, a display circuit having a display area switching function, reading display data stored in a designated display area from the video memory, and sending a display input signal of a corresponding resolution to the display device; A display capability storage unit for storing display capability information indicating a type and a range of a display region selectable by the display circuit; a storage region for display data detected by the storage region detection unit; and the display capability storage unit. Comparing means for determining the type of the display area to be selected by comparing the displayed display capability information, and A display area switching means for switching a display area of the display circuit. 2. The display capacity storage means comprises a volatile memory, and further comprises display capacity read means for reading display capacity information from an external storage device or the like into the display capacity storage means at the time of startup. The display area switching system according to claim 1. 3. The display area switching system according to claim 1, wherein said display capability storage means is a nonvolatile semiconductor memory built in said display circuit. 4. The storage area detection means detects a storage area by monitoring a write address of display data written to the video memory when a resolution or a display range is changed from an image processing unit of a computer device. The display area switching system according to claim 1, wherein 5. The storage area detection unit determines a storage area based on a display data write range notification signal sent from the image processing unit of the computer device when the resolution or the display range is changed. Display area switching system according to the above.