Illumination type optical recorded information reading device
February 7, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3705316 3754181 3784844 Optical reading apparatus with automatic gain control circuit Light emitting diode array having uniform illuminance distribution Apparatus for optically reading printed information Light emitting element array Linear light source Current mirror using resistor ratios in CMOS process Charge-eliminating apparatus of copier Patent #: 5065188 InventorsAssigneeApplicationNo. 653191 filed on 02/07/1991US Classes:235/455, Light level control315/297, Automatic regulation323/269, Linearly acting parallel connected362/244, Refractor type modifier362/800LIGHT EMITTING DIODEExaminersPrimary: Shepperd, John W.Attorney, Agent or FirmForeign Patent References
International ClassesG06K 007/10H05B 037/02 F21V 005/08 G05F 001/577 Foreign Application Priority Data1990-02-27 JPAbstractAn illumination type optical recorded information reading device including a plurality of light emitting elements, a photo detector for detecting optical indication on a media and converting the detected indication to electrical information, a plurality of driving elements for driving the light emitting elements, a driving current detector for detecting a total value of driving currents flowing through the driving elements, and a controller for comparing the total value with a reference value and generating a control signal to the driving elements so as to make a difference between the total value and the reference value constant. Further, a distribution of an illuminance of the light to be applied to the media is set in such a manner that the illuminance at positions spaced away from a central portion of a maximum detectable range of the photo detector is higher than that at the central portion, and that the illuminance at opposite end portions of the maximum detectable range is lower than that at the positions spaced away from the central portion. | |
