Light collecting and redirecting means

• US 4,766,424 A
• Filed: 03/30/1984
• Issued: 08/23/1988
• Est. Priority Date: 03/30/1984
• Status: Expired due to Term

• Current Assignee: Zenith Radio Corporation
• Original Assignee: Zenith Electronics Corporation (LG Corporation)
• Inventors: Adler, Robert, Strauss, Paul
• Primary Examiner(s): Curtis, Marshall M.
• Assistant Examiner(s): Fatahi-Yar, Mahmoud
• Application Number:
  US06/595,170
• Time in Patent Office: 1,607 Days
• Field of Search: 340/712, 340/365 P, 340/815.31, 250/221, 250/227, 350/96.1, 350/96.17, 350/96.18, 350/96.19, 40/547, 40/583
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An improved light collector, for collecting the light in a plurality of parallel light beams directed across the display surface of a touch panel apparatus and for redirecting it in a direction substantially perpendicular to the light beams for detection by a common detector positioned adjacent one end of the collector, comprises an elongated strip of light transmissive material terminated by a light collection station. A plurality of light reflecting elements is disposed inside and spaced along one side of the strip and each has a transverse dimension small in comparison to cross-section of the strip. The surface of each reflecting element is tilted with respect to the longitudinal axis of the strip. A like plurality of focusing elements is also disposed along the strip and each such element is individually associated with an assigned one of the reflecting elements. Each of the focusing elements is oriented and configured to collect light received in a direction substantially perpendicular to the longitudinal axis of the strip and to direct such collected light to its assigned reflecting element. Each of the focusing elements is spaced from its assigned reflecting element a distance such that the reflecting element is positioned at, or close to, the focal plane of its assigned focusing element. Each reflecting element is so tilted as to direct light received from its assigned focusing element to the light collection station.

Claims

1. In a touch panel graphics display apparatus having means for producing a plurality of substantially parallel light beams directed across a display surface of said apparatus, an improved light collector means for collecting light in said light beams and for redirecting it in a substantially common direction substantially perpendicular to said light beams for detection by a common detector means positioned adjacent one end of said collector,

said light collecting and redirecting means comprising:

an elongated strip of light transmissive material having a longitudinal axis, and being terminated by a light collection station;

a plurality of light reflecting elements disposed inside and spaced along one side of said strip and having a transverse dimension small in comparison to said strip cross-section,

the surface of each said reflecting element being tilted with respect to said longitudinal axis of said strip;

a like plurality of focusing elements disposed along said strip and individually associated with an assigned one of said reflecting elements,

each said focusing element being oriented and configured to collect light received in a direction substantially perpendicular to said longitudinal axis of said strip and to direct such collected light to said reflecting element assigned to said focusing element,

each said focusing element being spaced from its assigned reflecting element a distance such that said reflecting element is positioned at, or close to, the focal plane of its assigned focusing element,

each said reflecting element being so tilted as to direct light received from its assigned focusing element to said light collection station.

2. In a graphics display apparatus having:

a display device having a display surface,

a radiant energy source means, and

means for stimulating said radiant energy source to generate, effectively, a plurality of apparent discrete, time-sequentially occurring light sources collectively disposed along at least one edge of said display surface for producing a like plurality of light paths each of said light paths being individually associated with an assigned one of said light sources,

each said light path being defined, conjointly, by its said associated light source and by a light collector means arranged to accept only that light arriving within a predetermined range of angles centered upon a straight line extending from said associated light source to said collector means,

said light paths extending across said display surface,

radiant energy sensing means responsive to the output of said light sources and means for rendering said stimulating means operative in a patterned sequence so that the interruption of a particular one of said light paths is identifiable,

said display surface serving to display graphics in response to an operator'"'"'s command in the form of a pointing to a particular area of said display surface, which pointing interrupts at least one of said light paths, the improvement comprising;

light collector means comprising an elongated strip of light transmissive material terminated by a light collection station confronting said radiant energy sensing means,

said collector means being disposed along that edge of said display surface which is opposite said one edge for directing light intercepted from any of said plurality of light sources, to said collection station, provided that said intercepted light arrives at said collector within one of said defined light paths,

said light collector means further comprising an array of discrete focusing elements disposed along a face of said strip, each of said focusing elements being individually associated with an assigned one of said light sources,

each said focusing element being configured to collect and focus light arriving within that one of said defined light paths extending from said light source associated with said focusing element, and

a like array of discrete reflecting elements formed within said strip and adjacent a boundary thereof,

each said reflecting element being individually associated with and located at, or close to, the focal plane of an assigned one of said focusing elements for receiving said focused light collected by its said assigned focusing element and for redirecting said received light toward said light collection station,

the position, orientation and transverse dimensions of each said reflecting element being so chosen that only light arriving within its said associated focusing element'"'"'s assigned light path is redirected by said reflecting element.

5. The improvement set forth in claim 2 in which said focusing elements are equally spaced along said one face of said light guide and said reflecting elements are equally spaced along said light guide face opposite said one face.

6. The improvement set forth in claim 2 in which said light guide has an configuration corresponding to the contour of said display surface.

7. The improvement set forth in claim 2 in which said light guide comprises a tapered section interposed between said array of reflecting elements and said light collection station for inhibiting loss of redirected light.

8. The improvement set forth in claim 2 in which each of said focusing elements comprises a curved mirror of predetermined radius and each of said reflecting elements comprises a planar mirror.

9. The improvement set forth in claim 8 in which each of said focusing elements comprises a metallized coating for enhancing collection of light arriving within said defined light path.

10. The improvement set forth in claim 8 in which the geometric central axis of each of said curved mirrors is tilted approximately 8 degrees relative to a normal to said light guide face along which said reflecting elements are formed.

11. The improvement set forth in claim 2 in which each of said focusing elements comprises a lens and each of said reflecting elements comprises a planar mirror.

12. The improvement set forth in claim 11 in which the central axis of each of said lenses is normal to said light guide face along which said lenses are formed, in which the geometric center of said planar mirror is coincident with said lens axis and in which the plane of said planar mirror is disposed at approximately 45 degrees to said lens axis.

13. The improvement set forth in claim 11 in which each of said planar mirrors comprises a metallized coating for enhancing redirecting of focused light collected by its associated lens.

3. In a graphics display apparatus having:

a display device having a display surface,

a radiant energy source means,

and means for stimulating said radiant energy source to generate, effectively, a plurality of apparently discrete, time-sequentially occurring light sources collectively disposed along at least one edge of said display surface for producing a like plurality of light paths individually associated with an assigned one of said light sources,

each said light path being defined, conjointly, by its said associated light source and by a light collector means arranged to accept only that light arriving within a predetermined range of angles centered upon a straight line extending from said associated light source to said collector means,

said light paths extending across said display surface,

radiant energy sensing means responsive to the output of said light sources and means for rendering said stimulating means operative in a patterned sequence so that the interruption of a particular one of said light paths is identifiable,

said display surface serving to display graphics in response to an operator'"'"'s command in the form of a pointing to a particular area of said display surface, which pointing interrupts at least one of said light paths, the improvement comprising;

said light collector means comprising a light guide in the form of an elongated strip of light transmissive material terminated by a light collection station confronting said radiant energy sensing means,

said light guide being disposed along that edge of said display surface which is opposite said one edge, said light guide serving to direct light intercepted from any of said plurality of light sources, to said collection station provided that said intercepted light arrives at said light guide within one of said defined light paths,

said light guide comprising an array of discrete focusing elements formed along one face of said light guide, each of said focusing elements being individually associated with an assigned one of said light sources,

each said focusing element being configured to collect and focus light arriving within that one of said defined light paths extending from said light source associated with said focusing element, and

a like array of discrete reflecting elements formed along that face of said light guide opposite said one face,

each said reflecting element being individually associated with and located at, or close to, the focal plane of an assigned one of said focusing elements for receiving said focused light collected by its said assigned focusing element and for redirecting said received light toward said light collection station,

the position, orientation and transverse dimensions of each said reflecting elements being so chosen that only light arriving within its said associated focusing element'"'"'s assigned light path is redirected by said reflecting element.

4. In a graphics display apparatus having:

a display device having a display surface,

a first source of radiant energy,

means for stimulating said radiant energy sources to generate, effectively,

a first plurality of discrete, time-sequentially occurring light sources from said first source of radiant energy which are collectively disposed along a first edge of said display surface for producing a first plurality of light paths individually associated with an assigned one of said first light sources,

each of said first plurality of light paths being defined, conjointly, by its said associated light source and by a first light collector means arranged to accept only that light arriving within a predetermined range of angles centered upon a straight line extending from its said associated one of said first plurality of light sources to said first collector means,

and to generate a second plurality of discrete, time-sequentially occurring light sources from said second source of radiant energy which are collectively disposed along a second edge of said display surface for producing a second plurality of light paths individually associated with an assigned one of said second light sources,

each of said second plurality of light paths being defined, conjointly, by its said associated light source and by a second light collector means arranged to accept only that light arriving within a predetermined range of angles centered upon a straight line extending from its said associated one of said second plurality of light sources to said second collector means,

said first and second pluralities of light paths extending across said display surface,

first and second radiant energy sensors individually responsive to the output of said first and second pluralities of light sources, respectively, and

means for rendering said stimulating means operative in a patterned sequence so that the interruptions of particular ones of said light paths are identifiable,

said display surface serving to display graphics in response to an operator'"'"'s command in the form of a pointing to a particular area of said display surface, which pointing interrupts at least one light path associated with each of said first and second pluralities of light sources, the improvement comprising;

said first light collector means comprising a first light guide in the form of an elongated strip of light transmissive material terminated by a first light collection station confronting said first radiant energy sensor,

said first light guide being disposed along that edge of said display surface which is opposite said first edge for directing light intercepted from any of said first plurality of light sources to said first light collection station provided that said intercepted light arrives at said first light guide within one of said first plurality of defined light paths,

said first light guide comprising an array of discrete focusing elements formed along one face of said first light guide and individually associated with an assigned one of said first plurality of light sources,

each said focusing element of said first light guide being configured to collect and focus light arriving within that one of said first plurality of defined light paths extending from that one of said first plurality of light sources associated with said focusing element;

said first light guide further comprising a like array of discrete reflecting elements formed along that face of said first light guide opposite said one face,

each said reflecting element of said first light guide being individually associated with and located at, or close to, the focal plane of an assigned one of said first light guide focusing elements for receiving said focused light collected by its said assigned focusing element and for redirecting said received light toward said first light collection station,

the position, orientation and transverse dimensions of each of said first light guide reflecting elements being so chosen that only light arriving within that one of said first plurality of defined light paths extending from that one of said first plurality of light sources assigned to said focusing element of said reflecting element is redirected by said first guide reflecting elements; and

said second light colector means comprising a second light guide likewise in the form of an elongated strip of light transmissive material terminated by a second light collection station confronting said second radiant energy sensor,

said second light guide being disposed along that edge of said display surface which is opposite said second edge for directing light intercepted from any of said second plurality of light sources to said second light collection station, provided that said intercepted light arrives at said second guide within one of said second plurality of defined light paths,

said second light guide comprising an array of discrete focusing elements formed along one face of said second light guide and individually associated with an assigned one of said second plurality of light sources,

each said focusing element of said second light guide being configured to collect and focus only light arriving within that one of said second plurality of defined light paths extending from that one of said second plurality of light sources associated with said focusing element;

said second light guide further comprising a like array of discrete reflecting elements formed along that face of said second light guide opposite said one face,

each said reflecting element of said second light guide being individually associated with and located at, or close to, the focal plane of an assigned one of said second light guide focusing elements for receiving said focused light collected by its said assigned focusing element and for redirecting said received light toward said second light collection station,

the position, orientation and transverse dimensions of each of said second light guide reflecting elements being so chosen that only light arriving within that one of said second plurality of defined light paths extending from that one of said second plurality of light sources assigned to said focusing element of said reflecting element is redirected by said second guide reflecting elements.