Patent ID: 6039256
Filing Date: 2000-03-21
Classification: G06K

Abstract:
An optical information reading apparatus for reading an image of a reading object comprising:a case having a reading opening;a light receiving device accommodated in the case;a light emitting device positioned inside the case for irradiating light to the reading object located outside the case through the reading opening of the case;an image forming optical system positioned in the case for introducing light reflected from the reading object through the reading opening and forming an image of the reading object on the light receiving device;a lens barrel having an incident-side opening and a transmitting-side opening and holding the image forming optical system therein, the lens barrel being for guiding light reflected from the reading object into the case from the incident-side opening thereof, and sending the reflected light which has passed the image forming optical system to the light receiving device from the transmitting-side opening; anda dust-proof plate, located nearer to the reading opening than the light emitting device and the lens barrel, for transmitting the light emitted by the light emitting device therethrough and preventing dust from penetrating into the light emitting device and the lens barrel from the reading opening,wherein the incident-side opening of the lens barrel is placed proximately to the dust-proof plate to prevent the light emitted from the light emitting device and reflected from the dust-proof plate from traveling into the lens barrel.