Miniaturized optical mouse core

• US 20060284845A1
• Filed: 06/15/2005
• Published: 12/21/2006
• Est. Priority Date: 06/15/2005
• Status: Active Grant

• Current Assignee: Pixon Technologies Corp.
• Original Assignee: Pixon Technologies Corp.
• Inventors: Wu, Rong Yaw, Chen, Shih Che, Chang, Shu Ying
• Granted Patent: US 7,696,984 B2
• Time in Patent Office: Days
• US Class Current: 345/166
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface

Abstract

An optical mouse system with a high-angle optical path features small size and low power consumption. The illumination source and optical sensor are mounted in the same plane, directly on the PCB. The higher angle of the optical path causes more light to be reflected to the optical sensor, increasing optical efficiency and allowing a smaller, lower powered LED to be used. This also results in increased sensitivity of the optical sensor, allowing use of the mouse on surfaces on which conventional optical mice cannot function adequately. Sensitivity can be further increased by optional isolation of the optical sensor and illumination source. Lower power usage increases battery life for mobile or wireless-mouse use, while reducing thermal waste considerations. This allows the creation of a significantly smaller form factor for the overall package, thereby reducing materials costs and giving designers more flexibility for external design considerations.

Claims

1. An optical mouse system comprising:

a printed circuit board, having at least a first surface on which components are mounted;

an illumination source where an axis of the illumination source is parallel to a vector normal to the first surface of the printed circuit board;

a sensor, having a sensing surface comprising an array of sensing elements, where a vector normal to the sensing surface is parallel to a vector normal to the first surface of the printed circuit board; and

an illumination guide for directing illumination from the illumination source to a reference surface at an angle of less than about thirty-three degrees from a normal vector to said reference surface when said reference surface is parallel to the first surface of the printed circuit board, and for redirecting scattered illumination from said reference surface toward the sensing surface of the sensor.

2. The optical mouse system of claim 1 where the illumination source comprises a light-emitting diode (LED), an infrared-emitting diode (IRED), or a laser diode (LD).

3. The optical mouse system of claim 1 where the illumination guide comprises a first reflector, and a second reflector.

4. The optical mouse system of claim 3 where the first reflector is disposed at an angle substantially near forty-five degrees from a vector to the illumination source, and where the second reflector is disposed at an angle substantially near twenty-nine degrees from a reflection of the vector from the first reflector.

5. The optical mouse system of claim 3 where the illumination guide further comprises:

a first lens on a surface proximal to the illumination source and with an optical axis of the first lens substantially centered on and substantially parallel to an optical axis of the illumination source, for collimating illumination emitted by the illumination source into an illumination beam;

a second lens disposed on a source exit surface and with an optical axis of the second lens substantially centered in the illumination beam after the illumination beam reflects from the first reflector and then reflects from the second reflector, for spreading the illumination beam to illuminate the reference surface; and

a third lens disposed on an illumination entry surface and with an optical axis of the third lens substantially centered on and substantially parallel to a normal vector directed from a center of the sensing surface, for focusing onto the sensing surface illumination scattered from the reference surface.

6. The optical mouse system of claim 5, further comprising:

a fourth lens on the illumination guide where the illumination beam exits the illumination guide to fall onto the optical sensor.

7. The optical mouse system of claim 5 where the illumination guide further comprises texturing on a surface of the first lens and on a surface of the second lens, to remove artifacts in the illumination beam.

8. The optical mouse system of claim 5 where the illumination guide further comprises texturing on a surface of the third lens.

9. An optical mouse system comprising:

a printed circuit board, having at least a first surface on which components are mounted;

an illumination source where an axis of the illumination source is parallel to a vector normal to the first surface of the printed circuit board;

a sensor, having a sensing surface comprising an array of sensing elements, where a vector normal to the sensing surface is parallel to a vector normal to the first surface of the printed circuit board;

an illumination guide, for directing illumination from the illumination source to a reference surface at an angle of less than about thirty-three degrees from a normal vector to said reference surface when said reference surface is parallel to the first surface of the printed circuit board, and for redirecting scattered illumination from said reference surface toward the sensing surface of the sensor, said illumination guide comprising a first mating surface and a second mating surface;

a holder, having a first surface and a second surface, comprising;

an illumination source cavity, formed into the first surface of the holder, having an illumination exit aperture, and shaped to fit over the illumination source;

a sensor cavity, formed into the first surface of the holder, having an illumination entry aperture, and shaped to fit over the sensor; and

an illumination guide cavity, formed into the second surface of the holder, and having a guide surface shaped to fit against the first mating surface of the illumination guide;

where the first surface of the holder is disposed against the first surface of the printed circuit board; and

a containing clip, comprising;

an aperture through which illumination is directed and redirected;

a cavity, shaped to fit around the holder and the illumination guide, comprising an internal surface shaped to fit against the second mating surface of the illumination guide and the second surface of the holder such that the first mating surface of the illumination guide is held against the guide surface of the illumination guide cavity of the holder; and

a clip for attaching the containing clip either to the holder or to the printed circuit board;

where the containing clip encloses the holder and illumination guide and shields the sensor from external ambient illumination.

10. The optical mouse system of claim 9 where the containing clip and holder are made of nonreflective black polymer.

11. The optical mouse system of claim 9 where the holder further comprises a plurality of fingers extending from the first surface, and where the printed circuit board comprises a plurality of holes, such that the sizes and shapes of the holes of the printed circuit board match the sizes and shapes of the plurality of fingers extending from the first surface of the holder.

12. The optical mouse system of claim 9 where the illumination guide further comprises a first reflector and a second reflector.

13. The optical mouse system of claim 12 where the first reflector is disposed at an angle substantially near forty-five degrees from a vector to the illumination source, and where the second reflector is disposed at an angle substantially near twenty-nine degrees from a reflection of the vector from the first reflector.

14. The optical mouse system of claim 12 where the illumination guide further comprises:

a first lens on a surface proximal to the holder and with an optical axis of the first lens centered in the illumination exit aperture, for collimating illumination emitted by the illumination source into an illumination beam;

a second lens disposed on a source exit surface and with an optical axis of the second lens centered in the illumination beam after the illumination beam reflects from the first reflector and then reflects from the second reflector, for spreading the illumination beam to illuminate the reference surface; and

a third lens disposed on an illumination entry surface and with an optical axis of the third lens centered on a vector from a center of the sensing surface through a center of the illumination entry aperture of the holder, for focusing illumination scattered from the reference surface onto the sensing surface.

15. The optical mouse system of claim 14, further comprising:

a fourth lens disposed on the illumination guide where the illumination beam exits the illumination guide to fall onto the optical sensor.

16. The optical mouse system of claim 15 where the illumination guide further comprises texturing on a surface of the first lens, a surface of the second lens, a surface of the third lens, and a surface of the fourth lens to spread the illumination beam.

17. The optical mouse system of claim 9 further comprising a housing having a bottom surface shaped to move against the reference surface and a top surface, said housing containing the holder, the illumination guide, the clip, the printed circuit board, the illumination source, and the sensor within the housing.

18. The optical mouse system of claim 9 where the illumination source comprises a light-emitting diode (LED), an infrared-emitting diode (IRED), or a laser diode (LD).

19. An optical mouse system comprising:

a printed circuit board, having at least a first surface on which components are mounted;

an illumination source for providing light;

a sensor for detecting light; and

an illumination guide for directing illumination from the illumination source to a reference surface and for redirecting scattered illumination from said reference surface toward the sensor;

wherein the illumination source and sensor are mounted on a plane parallel to the first surface.

20. The optical mouse system of claim 19 wherein the illumination guide directs illumination from the illumination source to the reference surface at an angle of less than about thirty-three degrees from a normal vector to said reference surface when said reference surface is parallel to the first surface of the printed circuit board.