Ultra Thin Light Scanning Apparatus for Portable Information Device

1. An ultra thin optical scanning device for a portable information device, comprising: a light emitting device that emits light for sensing an object; a condensing lens that collects the light emitted from the light emitting device and emits the light in parallel to an optical axis of the light emitting device, and has a plurality of concentric Fresnel patterns; an object-side surface contacting the object and totally reflecting the light emitted from the light emitting device; an optical path changer part having reflective surfaces with a reflective coating layer formed thereon and refractive surfaces having no reflective coating layer, the optical path changer part guiding a path of the light emitted from the light emitting device to the object-side surface; an image formation part collecting the light totally reflected by the object-side surface, and transmitting the light; and a light receiver part forming an image by using the light transmitted by the image formation part, wherein the light which is reflected from the reflective surface arrives at the object-side with an incidence angle which is equal to or greater than a critical angle, wherein the light which is not reflected from the reflective surface arrives at the object-side with an incidence angle which is smaller than the critical angle, and wherein the critical angle satisfies a total reflection condition, and wherein the incidence angle of the light totally reflected by the object-side surface and collected by the image formation part is within 15° based on an optical axis.

2. The ultra thin optical scanning device of claim 1 , wherein the condensing lens is a Fresnel lens.

3. The ultra thin optical scanning device of claim 1 , wherein the light guided to the object-side surface by the optical path changer part forms an incidence angle such that the light is totally reflected from the object-side surface.

4. The ultra thin optical scanning device of claim 1 , wherein the light emitting device is a light emitting diode (LED).

5. The ultra thin optical scanning device of claim 4 , wherein the LED is a blue LED.

6. The ultra thin optical scanning device of claim 1 , further comprising a re-reflection surface that totally reflects the light totally reflected by the object-side surface to the image formation part.

7. The ultra thin optical scanning device of claim 1 , wherein the image formation part is a Fresnel lens.

8. The ultra thin optical scanning device of claim 1 , wherein the image formation part is an array lens.

9. The ultra thin optical scanning device of claim 1 , wherein the object-side surface, the image formation part, and the optical path changer part are integrally formed with a main body.

10. The ultra thin optical scanning device of claim 6 , wherein the object-side surface, the image formation part, and the re-reflection surface are integrally formed with a main body.

11. The ultra thin optical scanning device of claim 9 , wherein an assembly guide is disposed in a side portion of the main body.

12. An ultra thin optical pointing device for a portable information device, comprising: a light emitting device that emits light for sensing an object; a condensing lens that collects the light emitted from the light emitting device and emits the light in parallel to an optical axis of the light emitting device, and has a plurality of concentric Fresnel patterns; an object-side surface contacting the object and totally reflecting the light emitted from the light emitting device; an optical path changer part having reflective surfaces with a reflective coating layer formed thereon and refractive surfaces having no reflective coating layer, the optical path changer part guiding a path of the light emitted from the light emitting device to the object-side surface; an image formation part collecting the light totally reflected by the object-side surface, and transmitting the light; a light receiver part forming an image by using the light transmitted by the image formation part; a calculation part detecting a movement of the object by using the image, to calculate a coordinate value; and a display part displaying a pointer according to the calculated coordinate value, wherein the light which is reflected from the reflective surface arrives at the object-side with an incidence angle which is equal to or greater than a critical angle, wherein the light which is not reflected from the reflective surface arrives at the object-side with an incidence angle which is smaller than the critical angle, and wherein the critical angle satisfies a total reflection condition, and wherein the incidence angle of the light totally reflected by the object-side surface and collected by the image formation part is within 15° based on an optical axis.

13. The ultra thin optical pointing device of claim 12 , further comprising a re-reflection surface that totally reflects the light totally reflected by the object-side surface, to the image formation part.

14. The ultra thin optical pointing device of claim 12 , wherein the object-side surface, the image formation part, and the optical path changer part are integrally formed with a main body.

15. The ultra thin optical pointing device of claim 13 , wherein the object-side surface, the image formation part, and the re-reflection surface are integrally formed with a main body.

16. The ultra thin optical scanning device of claim 10 , wherein an assembly guide is disposed in a side portion of the main body.