Light guide bar and optical touch panel having the same
A light guide bar and an optical touch panel utilizing the light guide bar are provided. The light guide bar is applied to an optical touch panel with a sensing area. The light guide bar includes a bar body and a plurality of prisms. The bar body has a first receiving end, a light-exiting surface, and a structure surface. The light-exiting surface is opposite to the structure surface and faces the sensing area while the first receiving end is connected between an end of the light-exiting surface and an end of the structure surface. The prisms are formed on the structure surface. Each prism includes a first surface and a second surface respectively having a first angle and a second angle with respect to the structure surface, wherein the second surface is closer to the first receiving end than the first surface, and the second angle is larger than or equal to the first angle. The prisms are utilized to alter the angle of the light exiting the bar body to improve the touch-sensing effect of the optical touch panel utilizing the light guide bar.
1. A light guide bar for use in an optical touch panel having a sensing area, comprising:
a bar body having a first receiving end, a light-exiting surface, and a structure surface, wherein the light-exiting surface is opposite to the structure surface and faces the sensing area, the first receiving end is connected between an end of the light-exiting surface and an end of the structure surface; and
a plurality of prisms formed on the structure surface and respectively disposed along a first direction parallel to the first receiving end and along a second direction perpendicular to the direction of the first receiving end, wherein the plurality of prisms are arranged in intervals or in an interlaced manner along the first direction and along the second direction, each prism comprising a first surface and a second surface respectively having a first angle and a second angle with respect to the structure surface, wherein the second surface is closer to the light receiving end than the first surface, and the first angle is larger than or equal to the second angle.
2. The light guide bar of claim 1 , wherein the prisms have a smaller distribution density near the first receiving end.
3. The light guide bar of claim 1 , wherein the first angle is between 10° and 55°.
4. The light guide bar of claim 3 , wherein the second angle is between 3° and 10°.
5. The light guide bar of claim 3 , wherein the bar body comprises a second receiving end opposite to the first receiving end, wherein the first angle is equal to the second angle.
6. The light guide bar of claim 1 , wherein the second angle is between 10° and 55°.
7. An optical touch panel, comprising:
a sensing area;
a light guide bar, comprising:
a bar body having a first receiving end, a light-exiting surface, and a structure surface, wherein the light-exiting surface is opposite to the structure surface and faces the sensing area, the first receiving end is connected between an end of the light-exiting surface and an end of the structure surface;
a plurality of prisms formed on the structure surface and respectively disposed along a first direction parallel to the first receiving end and along a second direction perpendicular to the direction of the first receiving end, wherein the plurality of prisms are arranged in intervals or in an interlaced manner along the first direction and along the second direction, each prism comprising a first surface and a second surface respectively having a first angle and a second angle with respect to the structure surface, wherein the second surface is closer to the light receiving end than the first surface, and the first angle is larger than or equal to the second angle; and
a light source disposed opposite to the first receiving end of the bar body, wherein light generated from the light source enters the bar body and reflected by the first surface to exit from the light-exiting surface.
8. The optical touch panel of the claim 7 , wherein the prisms have a smaller distribution density near the first receiving end.
9. The optical touch panel of claim 7 , wherein the first angle is between 10° and 55°.
10. The optical touch panel of claim 9 , wherein the second angle is between 3° and 10°.
11. The optical touch panel of claim 9 , further comprising a second light source, wherein the bar body comprises a second receiving end opposite to the first receiving end, wherein the first angle is equal to the second angle.
12. The optical touch panel of claim 7 , wherein the second angle is between 10° and 55°.