LIGHT-BASED TOUCH SCREEN WITH SHIFT-ALIGNED EMITTER AND RECEIVER LENSES

• US 20110163998A1
• Filed: 03/21/2011
• Published: 07/07/2011
• Est. Priority Date: 11/04/2002
• Status: Active Grant

• Current Assignee: Neonode, Inc.
• Original Assignee: Neonode, Inc.
• Inventors: Shain, Joseph, Goertz, Magnus, Eriksson, Thomas, Pettersson, Robert, Sparf, Lars, Jansson, Anders, Karlsson, John, Kvist, Niklas
• Granted Patent: US 9,471,170 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421

Abstract

A touch screen including a housing, a display mounted in the housing, a plurality of collimating lenses mounted in the housing along two opposite edges of the display and arranged along the two edges so as to be shift-aligned relative to one another, a plurality of light pulse emitters mounted in the housing that are spaced apart from and transmit light pulses through the collimating lenses of one of the two edges over the display, a plurality of light pulse receivers mounted in the housing that are spaced apart from and receive the light pulses through the collimating lenses of the opposite of the two edges, and a calculating unit, mounted in the housing and connected to the receivers, that determines a location of a pointer on the display that partially blocks the light pulses transmitted by the emitters, based on outputs of the receivers.

Claims

1. A touch screen comprising:

a housing;

a display mounted in said housing;

a plurality of collimating lenses mounted in said housing along two opposite edges of said display and arranged along the two edges so as to be shift-aligned relative to one another;

a plurality of light pulse emitters mounted in said housing that are spaced apart from and transmit light pulses through said collimating lenses of one of the two edges over said display;

a plurality of light pulse receivers mounted in said housing that are spaced apart from and receive the light pulses through said collimating lenses of the opposite of the two edges; and

a calculating unit, mounted in said housing and connected to said receivers, that determines a location of a pointer on said display that partially blocks the light pulses transmitted by said emitters, based on outputs of said receivers.

2. The touch screen of claim 1, wherein said emitters and receivers are arranged in opposing rows, and wherein said emitters are shift-aligned relative to said receivers.

3. The touch screen of claim 1, wherein said collimating lenses comprise a plastic frame surrounding said display.

4. The touch screen of claim 1 further comprising a light guide for guiding light pulses, the light guide comprising micro-lenses for mufti-directional collimation of light pulses, and wherein said collimating lenses comprise a portion of said light guide.

5. The touch screen of claim 4 wherein said micro-lenses are comprised within said collimating lenses.

6. The touch screen of claim 4 wherein said micro-lenses are not comprised within said collimating lenses.

7. The touch screen of claim 1 further comprising:

a first light guide for guiding light pulses, comprising;

a first substantially parabolic reflective surface for reflecting light pulses transmitted by said emitters; and

a first substantially elliptical refractive surface, positioned substantially above said first substantially parabolic reflective surface, for refracting the reflected light pulses over said display to a second light guide; and

a second light guide for guiding light pulses, comprising;

a second substantially elliptical refractive surface for further refracting the refracted light pulses; and

a second substantially parabolic reflective surface, positioned substantially below said second substantially elliptical refractive surface, for reflecting the further refracted light pulses onto said receivers,

wherein said emitters and said receivers are positioned beneath said display, and wherein said collimating lenses comprise a portion of said first and said second light guides.

8. The touch screen of claim 7, wherein said first substantially parabolic reflective surface and said first substantially elliptical surface have the same focal location, and wherein said second substantially parabolic reflective surface and said second substantially elliptical surface have the same focal location

9. The touch screen of claim 1, wherein said collimating lenses are rigidly mounted in said housing, wherein said display is flexibly mounted in said housing, and wherein said calculating unit further determines that the pointer is performing a hard touch, based on increases in the outputs of said receivers.

10. The touch screen of claim 1 further comprising a plurality of inter-fitting infra-red transmissible plastic emitter units mounted in said housing, each said unit comprising:

at least one of said collimating lenses; and

at least one of said emitters, which transmit light pulses through said at least one of said collimating lenses.

11. The touch screen of claim 10, wherein said at least one collimating lens in each of said units receives light pulses from said unit'"'"'s at least one emitter and from a neighboring unit'"'"'s at least one emitter.

12. The touch screen of claim 10, wherein said units are pre-manufactured, prior to being assembled in the touch screen.

13. The touch screen of claim 10, wherein each of said units further comprises micro-lenses for multi-directional collimation of the light pulses.

14. The touch screen of claim 1, further comprising a plurality of inter-fitting infra-red transmissible plastic receiver units mounted in said housing, each said unit comprising:

at least one of said collimating lenses; and

at least one of said receivers, which receive light pulses through said at least one of said collimating lenses.

15. The touch screen of claim 14, wherein said at least one receiver in each of said units receives light pulses through said unit'"'"'s at least one collimating lens, and also receives light pulses through a neighboring unit'"'"'s at least one collimating lens.

16. The touch screen of claim 14, wherein said units are pre-manufactured, prior to being assembled in the touch screen.

17. The touch screen of claim 14, wherein each of said units further comprises micro-lenses for multi-directional collimation of the light pulses.

18. A touch screen comprising:

a housing;

a display mounted in said housing;

two light guides mounted in said housing and arranged along two opposite edges of said display, each light guide comprising micro-lenses for refracting incoming light in multiple directions;

a plurality of light pulse emitters mounted in said housing that transmit light pulses through a first one of said light guides over said display;

a plurality of light pulse receivers mounted in said housing that receive light pulses through the other one of said light guides; and

a calculating unit, mounted in said housing and connected to said receivers, to determine a location of a pointer on said display that partially blocks the light pulses refracted by said micro-lenses in the first light guide transmitted by said emitters, based on outputs of said receivers corresponding to light pulses refracted by said micro-lenses in said second light guide.

19. The touch screen of claim 18 further comprising two additional light guides mounted in said housing and arranged along the remaining two edges of said display, the four light guides comprising a single unit surrounding said display.