# US 10,375,270 B2 · Signal processing apparatus, image processing apparatus, and signal processing method

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- Number: US 10,375,270 B2
- Document ID: US10375270B2
- Status: Granted
- Kind: B2
- Application number: 16/018,672
- Filed: 2018-06-26
- Published: 2018-10-25
- Granted: 2019-08-06
- Earliest claimed: 2015-09-24
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Kazunori Togashi
- Web page: https://patentgrep.com/patent/US10375270B2

## CPC

- H04N 1/401: Compensating positionally unequal response of the pick-up or reproducing head (H04N1/403 takes precedence)
- H03M 1/1245: {Details of sampling arrangements or methods}
- H04N 1/03: with photodetectors arranged in a substantially linear array
- H04N 23/951: by using two or more images to influence resolution, frame rate or aspect ratio
- H04N 25/701: Line sensors
- H04N 25/745: {Circuitry for generating timing or clock signals}
- H04N 25/75: Circuitry for providing, modifying or processing image signals from the pixel array
- H04N 2201/0081: Image reader (H04N2201/0091 - H04N2201/0094 take precedence)
- H04N 2201/0094: Multifunctional device, i.e. a device capable of all of reading, reproducing, copying, facsimile transception, file transception
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C)

## Abstract

Provided is a signal processing apparatus that enables an image reading apparatus to perform higher speed processing of reading a document image. A signal processing unit is configured to convert six analog image signals obtained from a line sensor into six first signals, each of which is a 10-bit digital image signal, respectively, and to write the six first signals into a RAM at a first speed that is the same as a frequency of the analog image signals. The signal processing unit is configured to cause a serialization unit to read out from the RAM the six first signals as four second signals, each of which is a 10-bit digital image signal, at a second speed higher than the first speed, respectively, and to serialize the four second signals to generate six 7-bit serial signals.

## Claims

### Claim 1

An image reading apparatus comprising:
a sensor configured to read a document to output an analog image signal;
an AD converter configured to convert the analog image signal into digital image signal;
a memory configured to store the digital image signal, the digital image signal being written to the memory at a first speed;
a serializer configured to:
read out from the memory four second signals, each of which is a 10-bit digital image signal at a second speed lower than two times the first speed, respectively; and
serialize the four second signals to generate six 7-bit serial signals; and
a transmitter configured to convert the six 7-bit serial signals into low-voltage differential signals, respectively, and to transmit the low-voltage differential signals to an apparatus in a subsequent stage.

### Claim 2 (depends on 1)

The image reading apparatus according to claim 1, further comprising:
a receptor configured to convert the six low-voltage differential signals into six single end signals;
a deserializer configured to deserialize the six single end signals for conversion into parallel signals of four pixels; and
a second memory to which the parallel signals of four pixels are written.

### Claim 3 (depends on 1)

The image reading apparatus according to claim 1, wherein the sensor is configured to output analog image signals of red, blue, and green colors.

### Claim 4 (depends on 1)

The image reading apparatus according to claim 1, further comprising a flexible flat cable configured to transmit the low-voltage differential signals to an apparatus in a subsequent stage.

### Claim 5 (depends on 1)

The image reading apparatus according to claim 1, further comprising a timing signal generator configured to generate a timing signal;
wherein the sensor, the AD convertor, and the serializer operate based on the timing signal.