GB2243521A

GB2243521A - Image display system

Info

Publication number: GB2243521A
Application number: GB9008282A
Authority: GB
Inventors: Peter Evans
Original assignee: AFE DISPLAYS Ltd
Current assignee: AFE DISPLAYS Ltd
Priority date: 1990-04-11
Filing date: 1990-04-11
Publication date: 1991-10-30
Anticipated expiration: 2010-04-11
Also published as: GB2243521B; GB9008282D0

Abstract

An image display system comprises a processor (15) which receives image information and writes the information into a main memory means or area (12) from where it is fed to a screen (10) which displays the image, the processor (15) on receiving new information, writing into an auxiliary memory means or area (13) new image information relating to a part of the image within a predefined image area (20) which may for example contain a cursor, and writing into the main memory means (12) the remainder of the new image information (I') relating to that part of the new image outside the predefined image area (20). Thus when the cursor is moved (eg under control of a mouse 23 etc) any "new" thereby uncovered is obtainable from the auxiliary memory means (13). To enable the removal and subsequent reintroduction of the cursor, its image and area (20) are stored in a further memory means or area (14). <IMAGE>

Description

Title: Image Display System Description of Invention This invention relates to an image display system.

Systems are known in which a cursor can be displayed on a screen and moved around the screen under the control of an operator.

When it is desired to display a new image on the screen, at least if any part of the new image corresponds with the position the cursor occupies, the image obliterates the cursor which then has to be regenerated and superimposed on the new image.

According to the invention we provide an image display system comprising a processor which receives image information and writes the information into a main memory means from where it is fed to a screen which displays the image, the processor, on receiving new information, writing into an auxiliary memory means new image information relating to a part of the image within a predefined image area, and writing into the main memory means the remainder of the new image information relating to that part of the new image outside the predefined image area.

Thus, for example, where the predefined image area contains a cursor, the cursor is not obliterated by the new image information but rather any part of the new image which would fall within the predefined image area is diverted to the auxiliary memory means.

Conveniently information relating to the predefined image area is contained within a further memory means so that an operator may operate the system so that subsequently the new image information stored in the auxiliary memory means can replace the predefined image area information in the main memory means, but the predefined image area can be regenerated at will from the information contained in the further memory means.

Alternatively or additionally, the system may enable the operator to move the position of the predefined image area and the processor may be arranged to feed new image information from the auxiliary memory means to the main memory means to fill in any space in the new image left when the position of the predefined image area is changed.

The main memory means, auxiliary memory means and further memory means, where provided, may each comprise physically separate memory units but preferably each comprises an area of a single memory unit, the areas being individually addressable by the processor to enable different information to be stored in the different areas.

The invention will now be described with reference to the accompanying drawing which is a schematic illustration of an image display system in accordance with the invention.

Referring to the drawing, an image display system comprises a screen 10 on which an image I can be displayed, a memory unit 11 comprising three separate memory areas 12, 13, 14 which are individually addressable by a processor 15 to enable different information to be written into the individual memory areas 12-14.

The processor 15 is arranged to receive an input signal comprising image information from an upstream central processing unit (CPU) 16.

The memory area 12 is a main memory means and is adapted to store information which is to be read onto the screen 10.

The memory area 13 is an auxiliary memory means to which information can be written by the processor 15 instead of being written into the main memory means 12.

The memory area 14 is a further memory means which can contain information relating to a predefined area of the image on the screen 10, to enable a predefined image area to be regenerated.

In the present example, the predefined image area on the screen 10 is indicated at 20 and comprises a notional box containing a cursor 21. The position of the area 20 on the screen 10 can be moved under the control of an operator using, for example, a mouse, keyboardjtouch tablet, or other interface 23 with the CPU 16.

With information relating to the predefined image area 20 contained in the main memory means 12, when new image information is sent in an input signal to the processor 15, the processor reads the main memory means 12 and if any part of the new image would fall within the predefined image area 20, the processor 15 writes that part of the new image information into the auxiliary memory means 13 instead, the remainder of the new image information is written into the main memory means 12 from where it is read onto the screen 10 without the information relating to the cursor 21 or box 20 being obliterated in memory means 12, and without any part of the new image passing through the box 20.

Thus the image that appears on the screen will not be the same as the image contained in the input signal (indicated at 22) to the processor 15, but the image will appear as indicated at I' on the screen 10, i.e. with box 20 and cursor 21 still in their former positions.

The operator may then subsequently manipulate the image I' by causing the position of the box 20 and cursor 21 to change in which case the processor 15 may feed new image information I" from the auxiliary memory means 13 to the main memory means 12 which is then read onto the screen 10 to fill in any space of the new image left as the box 20 is moved.

Alternatively, the operator may decide to obliterate the cursor 21 by replacing the predefined image area information in the main memory means 12 with new image information I" from the auxiliary memory 13.

In this latter case, the cursor 21 and box 20 can always be regenerated when required because of the information stored in the further memory means 14.

In the example described, the main memory means 12, auxiliary memory means 13 and further memory means 14 are all different individually addressable areas of a single memory unit. In another example, two or more of the memory means can be provided by separate memory units.

If desired, the predefined image area 20 can be redefined by an operator and the new predefined image area information written into the further memory means 14 to replace the predefined image area information already contained therein.

In another embodiment, the predefined image area 20 information may be contained in a permanent memory such as a read-only memory (ROM).

It will be appreciated that in the example described the predefined image area is a notional box 20 around the cursor 21 and that the box 20 itself need not appear as part of the image on the screen 10. The predefined image area need not contain a cursor but may be of any other desired shape or configuration.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in the terms or means for performing the desired function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. An image display system comprising a processor which receives image information and writes the information into a main memory means from where it is fed to a screen which displays the image, the processor, on receiving new information, writing into an auxiliary memory means new image information relating to a part of the image within a predefined image area, and writing into the main memory means the remainder of the new image information relating to that part of the new image outside the predefined image area.

2. A system according to claim 1 wherein the predefined image area contains a cursor.

3. A system according to claim 1 or claim 2 wherein information relating to the predefined image area is contained within a further memory means so that the predefined image area can be regenerated at will from the information contained in the further memory means.

4. A system according to claim 3 wherein the operator can operate the system so that the new image information stored in the auxiliary memory means can replace the predefined image area information in the main memory means.

5. A system according to any one of claims 1 to 4 wherein the system enables the operator to move the position of the predefined image area, the processor being arranged to feed new image information from the auxiliary memory means to the main memory means to fill in any space in the new image left when the position of the predefined image area is changed.

6. A system according to any one of the preceding claims wherein the main memory means, auxiliary memory means and further memory means, where provided, each comprise physically separate memory units.

7. A system according to any one of claims 1 to 5 wherein the main memory means, auxiliary memory means and further memory means, where provided, each comprises an area of a single memory unit, the areas being individually addressable by the processor to enable different information to be stored in the different areas.

8. An image display system substantially as hereinbefore described with reference to and as shown in the accompanying drawings.