Ultra thin light scanning apparatus for portable information device

Abstract

Disclosed is an ultra thin optical scanning device for a portable information device, which includes an LED as a light source and totally reflects light from an object-side surface to form an image, thereby increasing a contrast ratio of the image and improving the resolution thereof. The ultra thin optical scanning device includes a light emitting device that emits light for sensing an object, an object-side surface contacting the object and totally reflecting the light emitted from the light emitting device, 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.

The invention claimed is: 
     
       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.