Method and equipment for controlling display of image data according to random-scan system

• US 5,675,363 A
• Filed: 04/13/1994
• Issued: 10/07/1997
• Est. Priority Date: 04/13/1993
• Status: Expired due to Fees

• Current Assignee: Hitachi Denshi Kabushiki Kaisha
• Original Assignee: Hitachi Denshi Kabushiki Kaisha
• Inventors: Omori, Shinji
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): CHANG, KENT WU
• Application Number:
  US08/226,837
• Time in Patent Office: 1,273 Days
• Field of Search: 345/203, 345/190, 345/201, 345/200, 345/185
• US Class Current: 345/544
• CPC Class Codes: G09B 9/301 by computer-processed or -generated image
• CPC Class Codes: G09G 1/07 with combined raster scan and calligraphic display
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels

Abstract

In an apparatus for displaying image data created by a computer according to the random-scan system, until the created display data is read out and displayed, in the time of buffering a buffer memory for temporarily storing the display data, the data is divided into plural blocks based on the display coordinate information added to the display data and is thus stored. When reading the data, the data is read out and displayed in sequence from blocks adjacent to each other.

Claims

1. A system for controlling an image data display for image data created by a computer on a screen of a display unit operated according to a random-scan system, comprising:

a memory having a plurality of memory blocks for storing said image data;

writing control means for allocating each of a plurality of image data created sequentially and independently in association with a display position on said screen by said computer to one of a plurality of predetermined blocks divided based on display coordinate data added to the image data and storing the allocated image data in said memory blocks as keeping the allocation;

reading control means for sequentially reading said image data stored in said memory blocks from adjacent memory blocks, regardless of the order in which said image data is written into said memory blocks, based on coordinates of the display screen; and

display control means for controlling display timing of said image data such that scanning performed in the random-scan system is based upon the sight-point coordinate data corresponding to said image data so as to display the read image data according to the random-scan system in said display unit.

2. A system for controlling display of image data as claimed in claim 1, wherein the random-scan system is predicated upon a travel time for an electronic beam to pass from one display location to another, therefore said display control means includes travel time calculating means for calculating the travel time required for the electronic beam to travel from a display location of preceding image data to another display location of current image data on said display unit, based on the display coordinate data added to current image data and the display coordinate data added to said preceding image read from said reading means;

and

means for controlling said display timing for displaying said current image data after the calculated travel time has passed.

3. A system for controlling display of image data as claimed in claim 2, wherein said travel time calculating means uses, for calculating the travel time, a larger one of an absolute value of a) a difference between an X-axis coordinate of the display coordinate data added to said preceding image data and an X-axis coordinate of the display coordinate data added to said current image data and b) an absolute value of a difference between a Y-axis of the display coordinate data added to said proceeding image data and a Y-axis of the display coordinate data added to said current image data.

4. A system for controlling display of image data as claimed in claim 2, wherein said plurality of blocks respectively correspond to each area formed by dividing said display screen, and said travel time calculating means calculates said travel time based on the maximum value of time required for an electronic beam to travel inside the block of said display screen provided in said display unit.

5. A system for controlling display of image data as claimed in claim 4, wherein said travel time calculating means uses, for calculating said travel time, a larger one of a) a difference of a number of blocks on the X axis and b) a difference of a number of blocks on the Y axis, between a block belonging to the display coordinate data added to said current image data and a block belonging to the display coordinate data added to said preceding image data, if the display coordinate data added to said current image data belongs to a different block from the display coordinate data added to said preceding image data.

6. A system for controlling display of a plurality of image data created by a computer on a screen of a display unit utilizing a random-scan system, comprising:

a memory having a plurality of memory blocks for storing said plurality of image data, all of said image data having display coordinate data which are generated sequentially and independently in association with respective display positions on said screen by said computer,

writing control means for allocating each of said plurality of image data to one of a plurality of predetermined blocks divided based on said display coordinate data added to each of said plurality of image data and for storing said allocated image data corresponding to said plurality of blocks into memory blocks, an order of said plurality of image data to be stored in said memory blocks being arranged so that said plurality of image data to be closely displayed are placed continuously in a writing order of said memory;

reading control means for reading said plurality of image data stored in said memory blocks and displaying said plurality of image data thus read on said display unit; and

display control means for controlling display timing of the image data such that scanning performed in the random-scan system is based upon the light-point coordinate data corresponding to said image data so as to display the read image data according to the random-scan system in said display unit.

7. A system for controlling display of image data as claimed in claim 6, wherein the random-scan system is predicated upon a travel time for an electronic beam to pass from one display location to another, therefore said display control means includes travel time calculating means for calculating the travel time required for the electronic beam to travel from a display location of preceding image data to another display location of current image data on said display unit, based on the display coordinate data added to current image data and the display coordinate data added to said preceding image read from said reading means;

and

means for controlling said display timing for displaying said current image data after the calculated travel time has passed.

8. A system for controlling display of image data as claimed in claim 7, wherein said travel time calculating means uses, for calculating the travel time, a larger one of an absolute value of a) a difference between an X-axis coordinate of the display coordinate data added to said preceding image data and an X-axis coordinate of the display coordinate data added to said current image data and b) an absolute value of a difference between a Y-axis of the display coordinate data added to said proceeding image data and a Y-axis of the display coordinate data to said current image data.

9. A system for controlling display of image data as claimed in claim 7, wherein said a plurality of blocks respectively correspond to each area formed by dividing said display screen, and said travel time calculating means calculates said travel time based on the maximum value of time required for an electronic beam to travel inside of the block of said display screen provided in said display unit.

10. A system for controlling display of image data as claimed in claim 9, wherein said travel time calculating means uses, for calculating said travel time, a larger one of a) a difference of a number of blocks on the X-axis and v) a difference of a number of blocks on the Y-axis, between a block belonging to the display coordinate data added to said current image data and a block belonging to the display coordinate data added to said preceding image data, if the display coordinate data added to said current image data belongs to a different block from the display coordinate data added to said preceding image data.

11. A system for controlling display of image data as claimed in claim 6, wherein

said writing control means includes means for counting the number of image data written in the blocks, and

said reading control means includes means for counting the remaining number of image data written in the blocks and means for completing the reading operation in response to the remaining number.

12. A method for controlling an image data display for image data created by a computer on a screen of a display unit utilizing a random-scan system, said method comprising the steps of:

allocating each of a plurality of image data sequentially created by said computer to any one of a plurality of blocks based on display coordinate data added to said image data;

storing the allocated image data in a memory;

reading said image data stored in said memory in a predetermined manner such that only blocks in which image data is stored and which are directly adjacent to one another on the screen of the display unit will be read in sequence, thereby minimizing reading time; and

displaying the sequentially read image data on the screen, such that scanning performed in the random-scan system is based upon the light-point coordinate data corresponding to said image data.

13. A system for controlling an image data display for image data created by a computer on a screen of a display unit operated according to a random-scan system, comprising:

a memory for storing said image data;

writing control means for allocating each of a plurality of image data sequentially created by said computer to any one of a plurality of blocks based on display coordinate data added to the image data and storing the allocated image data in said memory as keeping the allocation;

reading control means for sequentially reading said image data stored in said memory in a predetermined manner such that only blocks in which image data is stored and which are directly adjacent to one another on the screen of the display unit will be read in sequence, thereby minimizing reading time; and

display control means for controlling display timing of the image data such that scanning performed in the random-scan system is based upon the light-point coordinate data corresponding to said image data so as to display the read image data according to the random-scan system in said display unit.

14. A system as claimed in claim 13, wherein said memory comprises a first memory portion for storing said image data and a second memory portion for storing said allocated image data.

15. A method for controlling an image data display for image data created by a computer on a screen of a display unit utilizing a random-scan system, said method comprising the steps of:

allocating each of a plurality of image data sequentially created by said computer to any one of a plurality of blocks based on display coordinate data added to said image data;

storing the allocated image data in a memory;

reading said image data stored in said memory in a predetermined serpentine manner such that only blocks in which image data is stored and which are directly adjacent to one another on the screen of the display unit will be read in sequence, thereby minimizing reading time; and

displaying the sequentially read image data on the screen, such that scanning performed in the random-scan system is based upon the light-point coordinate data corresponding to said image data.

16. A system for controlling an image data display for image data created by a computer on a screen of a display unit operated according to a random-scan system, comprising:

a memory for storing said image data;

writing control means for allocating each of a plurality of image data sequentially created by said computer to any one of a plurality of blocks based on display coordinate data added to the image data and storing the allocated image data in said memory as keeping the allocation;

reading control means for sequentially reading said image data stored in said memory from adjacent blocks in a predetermined serpentine manner such that only blocks in which image data is stored and which are directly adjacent to one another on the screen of the display unit will be read in sequence, thereby minimizing reading time; and

display control means for controlling display timing of the image data such that scanning performed in the random-scan system is based upon the light-point coordinate data corresponding to said image data so as to display the read image data according to the random-scan system in said display unit.

17. A method for controlling an image data display for image data created by a computer on a screen of a display unit utilizing a random-scan system, the random-scan system is predicated upon a travel time for an electronic beam to pass from one display location to another said method comprising the steps of:

processing the image data by geometry transformation or rendering;

allocating each of a plurality of image data sequentially created by said computer to any one of a plurality of blocks based on display coordinate data added to said image data;

storing the allocated image data in a memory;

reading said image data stored in said memory in sequence from adjacent blocks on the screen;

assessing travel time information for the electronic beam corresponding to said sequentially read image data to travel from one light point location to a next light point location; and

displaying the sequentially read image data on the screen based on the assessed travel time information such that scanning performed in the random-scan system is based upon the light-point coordinate data corresponding to said image data.

18. A system for controlling an image data display for image data created by a computer on a screen of a display unit operated according to a random-scan system, the random-scan system is predicated upon a travel time for an electronic beam to pass from one display location to another comprising:

processing means for processing the image data by geometry transformation or rendering;

a memory for storing said image data;

writing control means for allocating each of a plurality of image data sequentially created by said computer to any one of a plurality of blocks based on display coordinate data added to the image data and storing the allocated image data in said memory as keeping the allocation;

reading control means for sequentially reading said image data stored in said memory from adjacent blocks based on coordinates of the display screen;

means for assessing travel information for the electronic beam corresponding to said sequentially read image data to travel from one light point location to a next light point location; and

display control means for controlling display timing of the image data based on the time travel information so as to display the read image data according to the random-scan system in said display unit, such that scanning performed in the random-scan system is based upon the light-point coordinate data corresponding to said image data.