JPH056156A - Display device - Google Patents

Abstract

PURPOSE:To avoid generation of write noise at changing a display content on the display scope of a display device and mixed existence of display contents. CONSTITUTION:In a display device provided with a liquid crystal display part 103 to display data, a RAM 101 for video to receive data, a display control part 102 to read data from the RAM 101 for video and display on the liquid crystal display part 103, and another control part 104 to rewrite the received data in the RAM 101 for video, it is featured that area A and area B to memorize display data are provided in the RAM 101 for video.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device used in copying machines, facsimiles, printers, etc. The present invention relates to a display device that eliminates a mixed data state.

[0002]

2. Description of the Related Art In conventional display devices used in copying machines, facsimiles, printers, etc., display data stored in a video RAM accessed by a display control unit is directly rewritten. In order to prevent the rewriting noise that occurs at this time,
By adding hardware such as cycle stealing and time sharing, the display data is rewritten by the other control units in anticipation of when the display control unit is not accessing the video RAM.

FIG. 6 shows a display example of a copying machine using such a system. FIG. 6A shows a state in which the normal size mode is released, and FIG. 6B shows a state in which the reduction mode is selected. Further, FIGS. 6C, 6D, and 6E show a state in which a pictorial display of the same size changes from the upper side to a pictorial display of a reduction in order.

[0004]

However, in the display device as shown above, the display device shown in FIG.
As shown in (d) and (e), the display screen before rewriting the display data and the display screen after rewriting are temporarily mixed, which is very difficult to see. This becomes more difficult to see as the rewriting area of the display section increases. In order to solve such a problem, there has been a problem that the program must be designed in consideration of the rewriting procedure.

The present invention has been made in view of the above, and an object of the present invention is to avoid generation of write noise when changing the display content of the display screen in the display device and avoid mixing of the display content at the time of switching. To do.

[0006]

In order to achieve the above-mentioned object, the present invention provides a display means for displaying data, a storage means for storing data, and a data read from the storage means for display on the display means. A display device provided with a display control means for displaying and a control means for rewriting stored data in the storage means, wherein the storage means is provided with an area for storing at least two sets of display data. .

Further, when the control means accesses the storage means for rewriting the display data, the area which the display control means does not access is accessed, and after the rewriting of the display data by the control means is completed, the display control is performed. It is preferable that the means switches access to an area where the display data has been rewritten by the control means, and after the area is switched, the same data as the display data is written in the other area.

Further, the display control means controls the display data of the specific area in the storage means to be displayed on the display means, and when the control means issues a display data rewriting request for the specific area, the area is displayed. It is desirable to display the data stored in the other area of the storage means until the rewriting operation for is completed.

[0009]

The display device according to the present invention uses at least two sets of memory areas for storing display data, which are provided in the video RAM as the storage means, and uses the control means to rewrite the display data to the memory area. Access,
Divided into access to the memory area for display,
Display control is performed on the display unit to avoid occurrence of write noise when changing display contents and mixing of display contents when switching.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory diagram showing a configuration example of a liquid crystal display device according to the present invention. In the figure, 101 is a video RAM (Random Access M) including an area A and an area B, each of which stores display data for one screen.
102) is a display control unit for transferring the display data stored in the video RAM 101 to the liquid crystal display unit 103, and 103 is a liquid crystal full-dot display device, on which a transparent sheet-like matrix touch switch is superimposed. A liquid crystal display unit that employs the combined configuration to display data, and 104 is another control unit that rewrites the display data in the video RAM 101.

Further, 105 is a switch input section for issuing an input command for rewriting display data, and 106 is a display control section 10.
2 and another control unit 104, an address switching unit for accessing the video RAM 101 together by means such as cycle stealing or time sharing, and 107 is another control unit 104.
Is an address signal from the display control unit 102, 109 is a data signal, and 110 is a control signal for transmitting to the display control unit 102 the completion of rewriting of the video RAM 101 by another control unit 104.

FIG. 2 shows the liquid crystal display unit 10 shown in FIG.
6 is a timing chart showing an operation example of display / rewriting with areas A and B of the video RAM 101 in FIG. The operation of the display device according to the present invention will be described with reference to FIGS. In FIG. 2, (a) shows a display area, (b) shows a write area, and (c) shows write data.

In FIG. 2, it is assumed that the display control unit 102 is displaying the display data described in the area A of the video RAM 101 on the liquid crystal display unit 103 at the time 201. Next, at a time point indicated by 202, another controller 104 issues a request for rewriting the display data of the video RAM 101. In this case, the other control unit 104 does not access the video RAM 1 by the display control unit 102.
Area B 01 is rewritten. At this time, the display control unit 102 continues to operate the video RAM 1 even during rewriting.
Since the display data stored in the area A 01 is displayed, the display content of the liquid crystal display unit 103 does not change.

Further, at 203, the other control unit 104 finishes the rewriting process of the display data in the area B of the video RAM 101, and at the same time notifies the display control unit 102 of the rewriting end by the control signal 110. RA for this video
Upon completion of rewriting the display data in the area B of M101, the display control unit 102 switches to display the display data written in the area B of the video RAM 101 on the liquid crystal display unit 103. At the same time, another control unit 104
Performs the same work as when the display data is rewritten in the area B of the video RAM 101.
Run against.

Next, when a new rewrite request is generated at the time indicated by 204, the same operation as the previous 202 and thereafter is executed. However, in this case, since the display control unit 102 is accessing the area B of the video RAM 101, the other control unit 104 causes the video RAM 101 to:
First, the rewriting operation of the area A of the video RAM 101 is executed.

Next, at the time indicated by 205, the above 2
As in the case of 03, the other control unit 104 is a video RAM.
The display data rewriting process to the area A of 101 is completed, and the control signal 110 notifies the display control unit 102 of the completion of the display data rewriting process. As a result, the display control unit 102 switches so that the display data in the area A of the video RAM 101 is displayed on the liquid crystal display unit 103. At the same time, the other control unit 104 controls the video RAM 1
The same operation as the rewriting of the display data of area A 01 is executed for area B of video RAM 101.
The same rewriting operation is repeated thereafter.

FIG. 3 is a timing chart showing another operation example of display / rewriting with area A and area B in the video RAM 101. 3A shows a display area, FIG. 3B shows a writing area, and FIG. 3C shows writing data.

As shown in FIG. 3, in this case, the display control unit 1
Reference numeral 02 controls the display data of the area A of the video RAM 101 to be displayed on the liquid crystal display unit 103. When a rewriting request for the video RAM 101 is issued from another control unit 104 (301, 302, 303), the video RAM 101 is rewritten.
The operation of rewriting 101 to area A ends (304, 3
05, 306) until the video RAM 10 is temporarily
The display data of the area B of No. 1 is controlled to be displayed on the liquid crystal display unit 103.

FIG. 4 is an operation panel showing a display example using the display device according to the present invention. The figure shows a display example of a multi-function copying machine.
As the paper size, A4 is selected.

FIG. 5 is an operation panel showing a display example having the same configuration as in FIG. The figure shows a display example of the same multi-function copying machine. As shown in the figure, the copy magnification / reduction mode is 71% reduction and the sheet size is A4.

As shown in FIGS. 4 and 5, by using the display device according to the present invention, it is possible to eliminate the unsightlyness due to the temporary mixture before and after rewriting on the display screen, and a very neat and easy-to-see display. It is a screen.

[0022]

As described above, according to the display device of the present invention, the display data buffer is the video RAM.
Since at least two sets are arranged in the inside and the RAM access for rewriting the display data and the RAM access for the display are separated from each other, the occurrence of writing noise when changing the display content of the display screen in the display device. It is possible to avoid mixing of display contents when switching.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a display device according to the present invention.

FIG. 2 is a video RAM 101 of a display device according to the present invention.
6 is a timing chart showing an operation example of display / writing in areas A and B in FIG.

FIG. 3 is a video RAM 101 of a display device according to the present invention.
9 is a timing chart showing another operation example of display / writing and areas A and B in FIG.

FIG. 4 is an operation panel (1 using the display device according to the present invention.
It is an explanatory view showing 00% same size, A4 size designation).

FIG. 5 shows an operation panel (7 using the display device according to the present invention.
It is explanatory drawing which shows 1% reduction and A4 size designation | designated.

FIG. 6 is an explanatory diagram showing a change state of the operation panel using the conventional display device from the normal size mode to the reduction mode.

[Explanation of symbols]

101 video RAM 102 display control unit 103 liquid crystal display unit 104 other control unit 105 switch input unit 106 address switching unit

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display location G09G 5/00 A 8121-5G H04N 1/00 106 B 4226-5C

Claims (3)

[Claims] 1. Display means for displaying data, storage means for storing data, display control means for reading data from the storage means and displaying it on the display means, and control means for rewriting stored data in the storage means. A display device comprising: a display device, wherein the storage means is provided with an area for storing at least two sets of display data. 2. When the control unit accesses the storage unit for rewriting the display data, the display control unit accesses an area which is not accessed, and after the control unit rewrites the display data, the display control is performed. 2. The display device according to claim 1, wherein the means switches access to an area in which the display data has been rewritten by the control means, and after the area is switched, the same data as the display data is written in the other area. . 3. The display control means controls the display data of a specific area in the storage means to be displayed on the display means, and when the control means issues a display data rewriting request for the specific area, the display area is rewritten. 2. The display device according to claim 1, wherein the data stored in another area of the storage means is displayed until the rewriting operation for is completed.