EP0274439A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Display system for plural display areas on one screen
Assignee: Brother Industries Ltd
•
Filing: 1988-01-07
•
Granted: —
•
Expires: 2008-01-07
Abstract
Abstract A display system for displaying characters on a screen which is divided into a plurality of display areas and for allowing a scroll within each of the display areas with one chip of display data RAM without image confusion between the display areas. The display data RAM is also divided into plural areas corresponding to the display areas. This system includes address conversion means provided between a display controller and the display data RAM for converting a virtual address outputted from the display control means into an actual address of the memory area. Here the virtual address is an address out of actual address of the memory area.
Inventors
- 👤 Susumu Brother Kogyo Kabushiki Kaisha Takeda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 20:15
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/007
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
181 words
A display system for displaying characters on a screen which is divided into a plurality of display areas and for allowing a scroll within each of the display areas, comprising: display data memory means for storing character data to be displayed on the screen, the display data memory means being divided into a plurality of memory areas each corresponding to respective display area; display control means for sequentially outputting addresses to each of the memory areas of the display data memory means in order to output the character data of the display data memory means designated by the addresses to each of the display areas of the screen corresponding to said each of the memory areas of the display data memory means; and address conversion means provided between the display control means and the display data memory means for converting a virtual address outputted from the display control means into an actual address of each of the memory areas of the display data memory means, the virtual address being an address outside the actual addresses in each of the memory areas.
Claim 2
Dependent Claim
181 words
A display system for displaying characters on a screen which is divided into a plurality of display areas and for allowing a scroll within each of the display areas, comprising: display data memory means for storing character data to be displayed on the screen, the display data memory means being divided into a plurality of memory areas each corresponding to respective display area; display control means for sequentially outputting addresses to each of the memory areas of the display data memory means in order to output the character data of the display data memory means designated by the addresses to each of the display areas of the screen corresponding to said each of the memory areas of the display data memory means; and address conversion means provided between the display control means and the display data memory means for converting a virtual address outputted from the display control means into an actual address of each of the memory areas of the display data memory means, the virtual address being an address outside the actual addresses in each of the memory areas.
Claim 3
Dependent Claim
59 words
The display system according to claim 1 wherein a first number of address designation lines of the display control means is greater than a second number of address designation lines of the display data memory means and the address conversion means is constructed from a logic circuit with inputs of the first number and outputs of the second number.
Claim 4
Dependent Claim
85 words
The display system according to 1 or 2 wherein the display system further comprises control means for outputting a start address and an amount of following addresses designating a part of an area of the display data memory means to the display control means in order to display characters of the part and for rewriting contents of the display data memory means and shifting the start address by an amount corresponding to one line for scrolling the display area of the screen by one line.
Claim 5
Dependent Claim
85 words
The display system according to 1 or 2 wherein the display system further comprises control means for outputting a start address and an amount of following addresses designating a part of an area of the display data memory means to the display control means in order to display characters of the part and for rewriting contents of the display data memory means and shifting the start address by an amount corresponding to one line for scrolling the display area of the screen by one line.
Claim 6
Dependent Claim
36 words
The display system according to claim 3, wherein the control means changes the start address from the virtual address to the actual address corresponding to the virtual address when the start address is the virtual address.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.