Image reading using irradiated light
The present invention relates to an image input device including a substrate, a light sensor, a light emitter, and a light guide. The light sensor, the light emitter, and the light guide are provided on the substrate. The light emitted from the light emitter is guided to a position above the light sensor by the light guide.
1. An image reading device that irradiates light emitted from a light emitter to an object and receives light diffused in the object by an optical sensor, wherein the light received by the optical sensor is light irradiated to a part of the object that is different from a part having an image entering the optical sensor, the device comprising:
the optical sensor;
the light emitter; and
a light guide comprised of a molded light transmissive resin for guiding the light emitted from the light emitter from a position of the light emitter to a position of the object above the optical sensor,
wherein the optical sensor, the light emitter and the light guide are provided on a substrate,
the light emitter surrounds the periphery of the optical sensor and is covered by a light entering surface of the light guide, and a light emitting surface of the light guide is placed above the optical sensor,
the light guide has a reflection surface for reflecting incident light from the light entering surface toward a position above the optical sensor, and
the image reading device is configured such that the light emitted from the light emitter passes through the light guide before reaching the object.
2. An image reading device according to claim 1 , wherein the object is a finger and said image reading device reads a fingerprint of the finger placed on the optical sensor.
3. An image reading device according to claim 2 , wherein said light guide is used as a guide to place the object at a predetermined position.
4. An image reading device according to claim 1 , further comprising a reflection film, wherein said reflection film is provided on the reflection surface.
5. An image reading device according to claim 1 , further comprising a light transmissive protector on the optical sensor and wherein the object is placed on said light transmissive protector.
6. An image reading device according to claim 5 , wherein said protector selectively allows light having a predetermined wavelength to pass therethrough.
7. An image reading device according to claim 1 , wherein said light emitter is provided at two sides of the optical sensor.
8. An image reading device according to claim 1 , further comprising a shade member disposed at least partially between the periphery of the optical sensor and said light emitter.
9. An image reading device according to claim 8 , wherein said shade member comprises a conductive material.