Correcting system of picture signal

Abstract

Abstract PURPOSE:To form a correcting device with a low-speed A/D converter, by obtaining the correcting information by reading the reference surface several times while switching successively the constant voltage level signals. CONSTITUTION:An image sensor delivers the same analog signal (a') in N times after reading N times the white reference surface provided at the reading position. A level counter 9 delivers the correcting signals (f) which are different each time and in order of smaller value. In response to the signals (f), a constant voltage level switch 8 delivers the constant level signals (m) successively in order of smaller value. An A/D converter 7 produces an output signal (e) when the signal (a) is larger than the signal (m) and writes the signal (f) into an RAM10. In such way, the correcting information on all bits of an image sensor are stored in the RAM10. When an original is actually read, the correcting signal given from the RAM10 is delivered to a slice level switch 13 to switch the slice level of the converter 7.

Inventors

• 👤 Kazuo Kurita
• 👤 和夫 栗田
• 👤 Keiichi Inoue
• 👤 井上　桂一

Bibliographic Details