Analog processing circuit, analog integrated circuit device, image reading device, and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorsMasamoto Nakazawa, Tohru Kanno
Life of this patent
Estimating the term…
Abstract
A first clamping unit clamps a base voltage of an input image signal to a predetermined reference voltage. A sampling-and-holding unit samples and holds the image signal after clamping or a reference signal that becomes the base voltage of the image signal. An amplifying unit amplifies the image signal sampled and held by the sampling-and-holding unit. An analog-to-digital converting unit converts the image signal after amplification into a digital image signal. A second clamping unit clamps the reference signal to a predetermined voltage.
Claims6
An analog processing circuit included in an image reading device, which is included in an image forming apparatus, the analog processing circuit comprising:
- an internal reference voltage;
- a first clamping unit configured to clamp a base voltage of an input image signal to a predetermined reference voltage obtained based on the internal reference voltage;
- a second clamping unit configured to obtain a reference signal from the internal reference voltage so as to have a same voltage as the predetermined voltage;
- a sampling-and-holding unit configured to receive input of the image signal after clamping and the reference signal, obtain a difference in the image signal after clamping and the reference signal as an image signal component of the image signal, and sample and hold an image signal consisting of the image signal component;
- an amplifying unit configured to amplify the image signal consisting of the image signal component obtained by the sampling-and-holding unit;
- and
- an analog-to-digital converting unit configured to convert the image signal after amplification into a digital image signal.
An analog integrated circuit device included in an image reading device, which is included in an image forming apparatus, the analog integrated circuit device comprising:
- an analog processing circuit that includes
- an internal reference voltage;
- a first clamping unit configured to clamp a base voltage of an input image signal to a predetermined reference voltage obtained based on the internal reference voltage,
- a second clamping unit configured to obtain a reference signal from the internal reference voltage so as to have a same voltage as the predetermined voltage,
- a sampling-and-holding unit configured to receive input of the image signal after clamping and the reference signal, obtain a difference in the image signal after clamping and the reference signal as an image signal component of the image signal, and sample and hold an image signal consisting of the image signal component,
- an amplifying unit configured to amplify the image signal consisting of the image signal component obtained by the sampling-and-holding unit, and
- an analog-to-digital converting unit configured to convert the image signal after amplification into a digital image signal.
Dependencies are inferred from the claim text.