JP2713938B2 - Display control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a display control device having a display resolution conversion function.

(Prior art) In recent years, office automation equipment has become increasingly light and thin, and so-called flat display panels such as plasma display panels and liquid crystal panels are used as display bodies even in workstations equipped with display units. It is conceivable to reduce the size and weight. These flat display panels are difficult to increase in resolution due to manufacturing technology, and are becoming widespread in relatively low resolution fields such as personal computers. However, the demand for smaller and lighter workstations in the field of high-resolution fields is becoming more and more important. ing. This is simply not a problem in character displays. That is, it can be easily realized by adjusting the number of dots of the dot font constituting the character to an appropriate resolution. The problem is how to absorb the difference in resolution in the graphic display. The absorption of the difference is realized by conversion by a conversion program which is aware of the resolution, or by performing resolution conversion by hardware.

(Problems to be Solved by the Invention) Among the above-mentioned resolution conversion means, in the resolution conversion means based on the former conversion program, there is a delay for operating the conversion program, and further, functions such as closed surface painting and the like are performed. However, there is a disadvantage that the surface may not be a closed surface due to a calculation error of the resolution conversion, and overflow of the paint may occur. In the latter hardware resolution conversion means, the timing control for the resolution conversion is very complicated, and the realization thereof requires a very large amount of hardware. There was also a problem in terms of aspects.

Further, as a resolution conversion means in the Y direction, a line buffer for storing one line of image data read from the frame buffer is provided, and after storing one line of image data in the same line buffer, the line buffer is synchronized with the frame buffer. There has been a mechanism for accessing the line buffer and ORing dot data between lines to perform compression in the Y direction. However, this mechanism requires a line buffer for Y direction resolution conversion. The mechanism had the disadvantage that it was very complicated.

The present invention has been made in view of the above circumstances, and has as its object to provide a display control device capable of easily realizing the above-described resolution conversion mechanism with a simple hardware configuration.

[Configuration of the Invention] (Means and Actions for Solving the Problems) The present invention provides a mechanism for converting the resolution of an image expanded in a graphic memory in the X-direction, and a frame for storing an image converted by the mechanism. A buffer having the above storage capacity, a mechanism for converting the resolution in the Y direction of the image stored in the buffer,
A first timing control mechanism for reading an image for one frame from the graphic memory within the frame display time and writing the image to the buffer via the X-direction resolution conversion mechanism; and a buffer for synchronizing the display timing of the display unit. Second timing control means for reading out the image stored in the Y-direction resolution conversion mechanism by the Y-direction resolution conversion mechanism, making the X-direction resolution conversion and the Y-direction resolution conversion independent with respect to the buffer, and The information access timing having a certain specific resolution and the access timing for display of a display unit having a resolution different from the above information are made independent, and replaced with a simple operation of memory access. This allows a simple hardware resolution conversion mechanism. It can be easily realized in road construction.

The present invention also relates to a display control system having a resolution conversion means for logically operating and compressing adjacent dots in the Y direction at a line interval determined by a compression ratio in the Y direction to compress an image to be displayed. Means for dividing the image of the line to be processed and the image of the line not to be processed separately into a plurality of sets, and inputting the line images of the sets to be processed in the divided memory A logic circuit that performs a logical operation for each corresponding dot, and a selection circuit that selects one of a line image obtained by the circuit and a line image not to be subjected to the operation and outputs the converted image data as resolution-converted display data. This eliminates the need for a line buffer for Y-direction resolution conversion, and enables simple memory control for resolution. It can realize the conversion mechanism.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

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

In the figure, reference numeral 1 denotes a graphic memory (GM) that develops graphic commands such as straight lines and circles and stores them, and has a resolution equivalent to the resolution of a display set as a conventional target. Reference numeral 2 denotes a first timing generator (TIM1) for generating a memory address of the memory 1 and a read timing signal in order to read information in accordance with the resolution of the information stored in the graphic memory 1. Reference numeral 3 denotes an X-direction resolution conversion mechanism for performing X-direction resolution conversion on image information stored in the graphic memory 1, and has a predetermined reduction / enlargement mechanism. Reference numeral 4 denotes a buffer memory (BM) for storing the conversion output data of the X-direction resolution conversion mechanism 3. The buffer memory (BM) for the X-direction information matches the resolution of the target display unit this time. Of the resolution. The buffer memory 4 is controlled so that the timing of writing the information after the resolution conversion in the X direction and the timing of reading the information for the resolution conversion in the Y direction can be asynchronous with each other. Here, 2 is used for resolution conversion (compression) by thinning out the ORing in the Y direction.
It has the function of reading more than one address simultaneously.

Reference numeral 5 denotes a second timing generator (TIM2) for generating information such as a memory address for reading display information in accordance with the resolution of the display unit to be processed this time and a raster address indicating a display position. Reference numeral 6 denotes a Y-direction resolution conversion mechanism for performing resolution conversion in the Y-direction.
Conceptually, it has the same configuration as the X-direction resolution conversion mechanism 3.

Reference numeral 11 denotes a character memory (CM) that stores character information in codes. Reference numeral 12 denotes a character generator (C) that generates a specific pattern based on the character code read from the character memory 11 and the display position in the character pattern.
G). An OR circuit 13 obtains unified display information by ORing the outputs from the graphic memory 1 and the character generator 12. Reference numeral 14 denotes a display unit (DSP) using a CRT display or the like.

FIGS. 2 (a) to 2 (c) are diagrams showing examples of processing patterns for explaining the resolution conversion processing operation of the above embodiment. Here, 2/3 compression is performed by thinning out the ORing in the X and Y directions, respectively. FIG.

The operation of the first embodiment will now be described with reference to FIGS.

The information shown in FIG. 2A stored in the graphic memory 1 is read out by the timing control according to the information generated by the first timing generator 2, and is read by the X-direction resolution conversion mechanism 3 in FIG. The resolution is converted only in the X direction as shown in FIG. Here it is reduced by 2/3 oring.

The information reduced by the X-direction resolution conversion mechanism 3 is stored in the buffer memory 4 by timing control according to the information generated by the first timing generator 2. The storage unit at this time is determined by the data width of the buffer memory 4.

The information stored in the buffer memory 4 is read out by the timing control according to the information generated by the second timing generator 5, and the Y-direction resolution conversion mechanism 6 converts the resolution only in the Y-direction as shown in FIG. Is done. Here, the reduction is performed by 2/3 oring reduction. In this reduction processing, first, information on lines 1 and 2 is simultaneously read and ORed for each corresponding dot, and then lines 4, 5, and lines 7 and 8 are performed in the same manner as above. Are ORed for each dot corresponding to. That is,
By simultaneously reading the raster information to be ORed at the time of reduction, information having a resolution before reduction different from that of the display unit 14 can be easily displayed and output even if the display timing of the display unit 14 having the reduced resolution is adjusted. As a result, information having the resolution shown in FIG. 2A is displayed on the display unit 14 with the resolution shown in FIG. In addition, the character memory 11,
The operation of the character generator 12 is the same as that of the existing device, and the description of the operation is omitted here.

As described above, the X-direction resolution conversion and the Y-direction resolution conversion are made independent from each other via the buffer memory 4, so that the access timing of information having a certain conventional resolution and the display unit having a resolution different from the above-mentioned information can be obtained. The access timing for display can be completely independent, and the resolution can be easily converted by replacing it with a simple operation called memory access. In addition, since a graphic memory having a conventional resolution is provided, and the information is read out by the software, the compatibility of the software can be assured, and the software according to the conventional resolution can be effectively used without being conscious of the resolution of the display unit 14.

Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 3 is a block diagram showing a second embodiment of the present invention. Here, a case where image information to be subjected to resolution conversion is compressed by 2/3 in the X and Y directions, respectively, is taken as an example.

In the figure, reference numeral 31 denotes an X-direction OR compression circuit for reducing image information to be subjected to resolution conversion by 2/3 ORing only in the X direction. 32 to 34 are frame buffers (F-BUS) divided (grouped) in accordance with the compression ratio, 32 is a frame buffer storing only the [3n] th scan line, and 33 is the [3n + 1] th scan line. A frame buffer 34 stores only scan lines, and a frame buffer 34 stores only [3n + 2] th scan lines. 35,3
Reference numeral 6 denotes a component of a Y-direction OR compression circuit 37 for reducing the image information by 2/3 ORing only in the Y-direction. 35 denotes a [3n] -th scan line stored in the frame buffer 32 and a frame buffer 33. An OR circuit for ORing the stored [3n + 1] -th scan line for each dot corresponding to the Y direction, and a scan line OR-compressed by an OR circuit 35 and a [3n + 2] -th scan line stored in the frame buffer 34 Are output alternately.

Here, the operation of the second embodiment shown in FIG. 3 will be described with reference to FIG.

The image information (original image) shown in FIG. 2 (a) to be subjected to resolution conversion is serially input to the X-direction OR compression circuit 31, and 2/3 ORing in the X-direction as shown in FIG. 2 (b). Scaled down. The information reduced by 2/3 in the X direction is stored in the n-th frame buffer 32 in units of scan lines in n +
The first data is sequentially written into the frame buffer 33, and the (n + 2) th data is sequentially written into the frame buffer.

The information stored in the frame buffers 32, 33, and 34 is read at the refresh rate to be converted. At this time, information for one scan line is simultaneously read from the frame buffer 32 and the frame buffer 33 at the same time. Is OR-compressed by the OR circuit 35 of the Y-direction OR compression circuit 37,
Output via selector 36. Next, frame buffer 34
The information for one scan line is read from the
Through. By repeatedly performing this operation,
From the Y direction OR compression circuit 37, in the X direction and Y direction respectively
2/3 compressed. The image information shown in FIG. 2 (c) is output and displayed on the display unit.

Such resolution conversion means by OR compression eliminates the need for a line buffer for OR compression in the Y direction, which is indispensable in the past, and further eliminates the need for an access mechanism for the buffer, thereby simplifying the configuration of the entire apparatus. .

In the above-described embodiment, the case where the compression is performed by 2/3 in both the X direction and the Y direction has been described as an example.

[Effects of the Invention] As described above in detail, according to the display control device of the present invention,
A mechanism for converting the resolution of the image developed in the graphic memory in the X direction, a buffer having a storage capacity of one frame or more for storing the image converted by the mechanism,
A mechanism for converting the resolution in the Y direction of the image stored in the buffer, and reading an image for one frame from the graphic memory within one frame display time of the display unit, to the buffer via the X direction resolution conversion mechanism A first timing control mechanism for writing, and a second timing control means for reading out the image stored in the buffer in synchronization with the display timing of the display unit and performing resolution conversion by the Y-direction resolution conversion mechanism. The X-direction resolution conversion and the Y-direction resolution conversion are made independent with the buffer interposed therebetween, so that the access timing of information having a certain specific resolution to be converted and the display timing of a display unit having a resolution different from the above information are displayed. And memory access timing independently of each other. By was replaced by a simple operation structure can be easily realized resolution conversion mechanism hardware with a simple circuit configuration.

Further, according to the display control device of the present invention, the image to be displayed is displayed at the line interval determined by the compression ratio in the Y direction.
In a display control system having a resolution converting means for performing logical operation and compressing adjacent dots in a direction, a frame memory holds an image of a line to be operated on and an image of a line not to be operated separately. Means for dividing the set into a plurality of sets, a logic circuit for inputting a line image of the set to be operated on the divided memory and performing a logical operation for each corresponding dot, a line image obtained from the circuit, and A selection circuit for selecting one of the non-target line images and outputting as resolution-converted display data, thereby eliminating the need for a line buffer for Y-direction resolution conversion and simplifying the configuration. Can realize a resolution conversion mechanism.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention, and FIGS. 2 (a) to 2 (c) are diagrams each showing a pattern transfer for explaining a resolution conversion operation in the above embodiment. 3
FIG. 7 is a block diagram showing a second embodiment of the present invention. 1. Graphic memory (GM), 2. First timing generator (TIM1), 3. X-direction resolution conversion mechanism, 4.
... Buffer memory (BM), 5 ... second timing generator (TIM2), 6 ... Y-direction resolution conversion mechanism, 11 ... Character memory (CM), 12 ... Character generator (C
G), 13… OR circuit, 14… Display unit (DS
P), 31 ... X direction OR compression circuit, 32, 33, 34 ... frame buffer (F-BUF), 35 ... OR circuit (OR), 36 ... selector, 37 ... Y direction OR compression circuit.

Claims (2)

(57) [Claims] A display unit having a predetermined display resolution; a graphic memory in which a display image is expanded; a first resolution conversion means for converting the resolution of the image expanded in the memory in the X direction; A buffer having an image storage capacity for at least one frame for storing the image converted in step (a), second resolution conversion means for converting the resolution in the Y direction of the image stored in the buffer, and one frame display of the display unit In time, an image for one frame is read out from the graphic memory, and the resolution is converted by the first resolution conversion means, and then written into the buffer. The first timing control means is synchronized with the display timing of the display unit. Read out the image stored in the buffer by using the second resolution conversion means. Display control apparatus characterized by comprising and a second timing control means for resolution conversion. 2. A display control method comprising a resolution conversion means for performing logical operation on adjacent dots in the Y direction at a line interval determined by a compression ratio in the Y direction and compressing an image to be displayed, and performing the operation. A frame memory divided into a plurality of sets that separately hold a line image and an image of a line that is not the target of operation, and a line image of the target set of the memory that is divided into a plurality of sets. A display control device comprising: a logic circuit that performs a logical operation; and a selection circuit that selects and outputs one of a line image obtained by the circuit and a line image that is not an object of the operation.