Methods and apparatus for transferring data from a display screen

• US 6,281,820 B1
• Filed: 07/12/1999
• Issued: 08/28/2001
• Est. Priority Date: 07/12/1999
• Status: Expired due to Fees

• Current Assignee: Pointset Corporation
• Original Assignee: Pointset Corporation
• Inventors: Fields, Kyle
• Primary Examiner(s): Jeanpierre, Peguy
• Assistant Examiner(s): Jeanglaude, Jean Bruner
• Application Number:
  US09/352,516
• Time in Patent Office: 778 Days
• Field of Search: 341/137, 345/89, 345/84, 395/128, 395/122, 348/666
• US Class Current: 341/137
• CPC Class Codes: H03M 1/32 using cathode-ray tubes or analoguous two-dimensional deflection systems

Abstract

Luminance or color modulation of a display screen is used to transfer data to an external receiving device. At least a portion of the display screen is modulated, such as by intensity modulation, to represent a data digit. By using a plurality of intensity levels greater than 2, it is possible to represent data digits having a numerical base greater than 2. For example, providing modulation with ten different intensity levels allows each modulation “dwell” to represent a decimal digit. The modulation is sensed by a photodetector in the external receiving device and converted to the corresponding data digit.

Claims

1. A method of transferring data from a display screen to a receiving device comprising the steps of:

modulating intensity of at least a portion of the display screen to represent a data digit having a numerical base greater than two with a corresponding one of a plurality of intensity levels greater than two, wherein said one intensity level is maintained for a dwell of at least 50 msec.; and

sensing the modulated intensity level in the receiving device.

2. The method of claim 1 wherein the step of modulating intensity comprises displaying a shade of gray.

3. The method of claim 1 wherein the step of modulating intensity comprises displaying a color.

4. The method of claim 1 wherein the step of modulating intensity comprises displaying a pattern of black and white pixels.

5. The method of claim 4 wherein the pattern comprises a regular pattern of cells.

6. The method of claim 4 wherein the pattern comprises an irregular graphic pattern.

7. The method of claim 1 wherein the step of modulating intensity of at least a portion of the display screen comprises modulating the intensity of an array of locations and wherein the receiving device includes a plurality of intensity detectors in an array corresponding to the array of locations.

8. The method of claim 7 wherein the array of locations comprises four quadrants.

9. The method of claim 1 wherein the step of modulating comprises displaying a plurality of colors and wherein the receiving device includes a plurality of detectors sensitive to respective ones of the plurality of colors.

10. A method of transferring data from a display screen to a receiving device comprising the steps of:

modulating color of at least a portion of the display screen to represent a data digit having a numerical base greater than two with a corresponding one of a plurality of colors greater than two, wherein said one color is maintained for a dwell of at least 50 msec.; and

sensing the modulated color in the receiving device.

11. A method of transferring data from a display screen to a receiving device comprising the steps of:

displaying a graphic pattern on the display screen for a dwell of at least 50 msec., said graphic pattern comprising a first number of white pixels and a second number of black pixels, the first number of white pixels to the second number of black pixels being a predetermined ratio selected from a set of predetermined ratios, said set having more than two members so that the selected ratio represents a corresponding data digit having a numerical base greater than two; and

sensing the ratio of white pixels to black pixels in the receiving device.

12. A method of transferring data from a display screen to a receiving device comprising the steps of:

modulating intensity of at least two colors on the display screen;

modulating a phase relationship between the modulated colors to represent a data digit having a numerical base greater than two with a corresponding one of a plurality of phase relationships greater than two, wherein said one phase relationship is maintained for a dwell of at least 50 msec.; and

sensing the modulated phase relationship in the receiving device.

13. A method of transferring data from a display screen to a receiving device comprising the steps of:

sequentially changing at least one of intensity or color of at least a portion of the display screen;

modulating a time interval between successive changes to represent a data digit having a numerical base greater than two with a corresponding one of a plurality of time intervals greater than two, wherein each of said plurality of time intervals is at least 50 msec.; and

sensing the modulated time interval in the receiving device.