Title:
ANALOG-TO-DIGITAL CONVERTER GAMMA-CORRECTED IN PIECEWISE LINEAR WAY
Document Type and Number:
Japanese Patent JPH07212232
Kind Code:
A
Abstract:
PURPOSE: To obtain a digital output from a high quality gamma corrected analog input signal by means of two conversion stages and interconnected circuits to generate a corrected digital signal. CONSTITUTION: In a first conversion stage, a digital encoder 40 encodes the outputs of comparators 38, and generates the most significant bits A4 -A7 of a desired piece-wise linear gamma corrected digital signal. Those most significant bits are supplied to a control system 42, and converted into an analog voltage VDAC to be transmitted to a D/A converter 60. The control system 42 selects a voltage Vhigh2 , and applies it to the top of a ladder 44 of the linear resistance of comparators 48 forming the second conversion stage. A differential amplifier 50 generates an adjusted analog signal proportional to a difference between two signals, that is, an original analog signal and the analog voltage VDAC, and applies it to each comparator 48. A second digital encoder 40 receives the outputs of the comparator 48, and generates the least significant bits A3 -A0 of a piece-wise linear gamma corrected digital signal.
Inventors:
DEIBUITSUDO MAIKERU BOISUBUAAT
Application Number:
JP28690594A
Publication Date:
August 11, 1995
Filing Date:
November 21, 1994
Export Citation:
Assignee:
EASTMAN KODAK CO
International Classes:
H04N5/202; H03M1/12; H03M1/14; H03M1/36; H04N1/407; H03M1/16; (IPC1-7): H03M1/14; H03M1/36; H04N1/407; H04N5/202
Attorney, Agent or Firm:
Tadahiko Ito (1 outside)
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