Title:
PICTURE READER
Document Type and Number:
Japanese Patent JP3150191
Kind Code:
B2
Abstract:
PURPOSE: To simply correct characteristics for a lamp itself, a lighting power supply circuit and an output of a light receiving element or the like for proper color reproduction even when the difference from those is high depending on individual components in the reader having a projection light source and the light receiving element receiving a projected light.
CONSTITUTION: In the reader provided with a light projection light source 101 and a light receiving element 109 receiving its projected light, an operation section 129 makes measurement command for the luminous quantity characteristic of the light source and the gain characteristic or the like for an analog amplifier 111, a CPU 121 is used to measure the characteristics and a conversion table is formed in a memory to correct the characteristics based on the result of measurement. Control parameters (lamp lighting voltage command, analog amplifier gain, logarithmic transformation table shift quantity) are obtained by referring the conversion table in the case of the correction. The measured data are stored in the memory till a succeeding measurement command is received.
Inventors:
Takuyuki Matsuo
Kiyohisa Sugishima
Kiyohisa Sugishima
Application Number:
JP9974292A
Publication Date:
March 26, 2001
Filing Date:
April 20, 1992
Export Citation:
Assignee:
Canon Inc
International Classes:
G06T1/00; H04N1/04; H04N1/00; H04N1/19; H04N1/40; H04N1/407; (IPC1-7): H04N1/19
Domestic Patent References:
| JP6013547U |
Attorney, Agent or Firm:
Keizo Nishiyama (1 person outside)