SYSTEM FOR READING OUT THE COORDINATES OF INFORMATION DISPLAYED ON A MATRIX TYPE DISPLAY DEVICE

• US 3,832,693 A
• Filed: 08/21/1972
• Issued: 08/27/1974
• Est. Priority Date: 08/29/1971
• Status: Expired due to Term

• Current Assignee: Hiroyuki Ishizaki, Shozo Umeda, Teruo Toba
• Original Assignee: Hiroyuki Ishizaki, Shozo Umeda, Teruo Toba
• Inventors: Toba, Teruo, Umeda, Shozo, Ishizaki, Hiroyuki
• Primary Examiner(s): Henon, Paul J.
• Assistant Examiner(s): Chapnick, Melvin B.
• Application Number:
  US05/282,022
• Time in Patent Office: 736 Days
• Field of Search: 340/172.5,324A,173LP 178/18,19,20 315/10
• US Class Current: 345/182
• CPC Class Codes: G06F 3/0386 for light pen

Abstract

For reading out the coordinates of information on a matrix type display, a read pulse scans the display surface. In the first embodiment, the display surface is divided into a plurality of blocks in both X and Y directions. First, the scanning is carried out with regard to the blocks in the X direction. Second, when an information signal is detected in any block, the above-mentioned operation is repeated with regard to the Y direction, and the coordinates of the information signal can be read out. In the second embodiment, the display surface is divided into 2 blocks in both X and Y directions and the scanning is first carried out with regard to the two blocks in the X direction. When the information signal is detected in one of the two blocks, the block is further divided into two blocks. By repeating this process, the electrode which includes the information signal is detected. Secondly, the above-mentioned operation is repeated with regard to the Y direction, and the coordinates of the information signal can be read out. Further, in the abovementioned two embodiments, the coordinates can be read out whether the coordinates are in the fired cell or in the non fired cell without carrying out special operations.

Claims

1. A system for reading out the coordinates of a matrix type display comprising;

a. a display device having a plurality of radiation points which are arranged in a matrix form and are connected to a plurality of row and column driving lines so as to individually control the radiation of said radiation points;

b. light detecting means positioned in a region corresponding to said radiation points on said display device;

c. a read out signal generator for producing a read out signal;

d. gate circuits connected between said read out signal generator and said driving lines to selectively supply said read out signal to said driving lines;

e. an address circuit for generating output signals for selectively opening said gate circuits in accordance with an address signal;

f. dividing address control means connected to said address circuit for dividing said row and column driving lines into a plurality of blocks, said dividing address control means generating an address signal in turn at every block to address simultaneously said plurality oF driving lines belonging to each said block and being controlled by a control signal thereby to gradually divide one of said blocks into a minimum divided block corresponding to one driving line; and

, g. circuit means connected to said light detecting means for supplying a control signal to said dividing address control means in accordance with radiation due to said read out signal of said radiation points at which said light detecting means is positioned whereby said system reads out the coordinates of said radiation point at which said light detecting means is positioned from the address condition when said light detecting means detects said radiation due to said read out signal to said minimum divided block corresponding to one driving line.

2. A system for reading out the coordinates of a matrix type display according to claim 1, wherein said display device comprises a plasma display panel having an inherent memory due to a wall charge, and a plurality of discharging points as said radiation points which are provided in a discharging space filled with ionizable gas at each cross point of first and second sets of electrodes arranged at right angles to each other, said first and second sets of electrodes being connected respectively to said row and column driving lines, a sustaining signal generator for generating a sustaining signal which is supplied to said first and second sets of electrodes to sustain the discharge of fired discharging points, and wherein said read out signal comprises a pulse having a voltage level which is capable of changing the polarity of the wall charge produced by the previous sustaining voltage in said fired discharging points, whereby said system reads out the coordinates of said fired discharging point when said light detecting means is positioned on the fired discharging point.

3. A system for reading out the coordinates of a matrix type display according to claim 1, wherein said dividing address control means divides said row and column driving lines into a first half block and a second half block, and when said light detecting means is positioned in said first half block, said read out signal is supplied to one of the half block of said first half block, and when said light detecting means is not positioned in said first half block said read out signal is supplied to one of the half block of said second half block.

4. A system for reading out the coordinates of a matrix type display according to claim 1, wherein said display device comprises a plasma display panel having an inherent memory due to a wall charge, and a plurality of discharging points as said radiation points which are provided in a discharging space filled with ionizable gas at each cross point of first and second sets of electrodes arranged at right angles to each other, said first and second sets of electrodes being connected respectively to said row and column driving lines, and a sustaining signal generator for generating a sustaining signal which is supplied to said first and second sets of electrodes to sustain the discharge of fired discharging points, and wherein said read out signal comprises a pulse having a voltage level which exceeds the firing voltage and an erase pulse which follows said pulse, whereby said system reads out the coordinate of a non-fired discharging point when said light detecting means is positioned on the non-fired discharging point.

5. A system for reading out the coordinates of a matrix type display according to claim 1, wherein said display device comprises a plasma display panel having an inherent memory due to a wall charge, and a plurality of discharging points as said radiation points which are provided in a discharging space filled with ionizable gas at each cross point of first and second sets of electrodes arranged at right angles to each other, said first and second sets of electrodes being connected respectively to said row and column driving lines, and a sustaining signal generator for generating a sustainIng signal which is supplied to said first and second sets of electrodes to sustain the discharge of fired discharging points, whereby said read out signal is provided with a first pulse which has the same polarity as that of the previous sustaining voltage and has a voltage level which exceeds that of the firing voltage, a second pulse which follows said first pulse and having a level of the erasing voltage, and a third pulse which follows said second pulse and having a voltage level substantially equal to said sustaining voltage, and when the light detecting means is positioned on a fired discharging point, the radiation of a fired discharging point due to said third pulse is detected, and when the light detecting means is positioned on a non fired discharging point, the radiation of a non fired discharging point due to said first pulse is detected.