# US 9,521,288 B2 · Sheet-fed scanner and image scanning method using the same

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- Number: US 9,521,288 B2
- Document ID: US9521288B2
- Status: Granted
- Kind: B2
- Application number: 14/716,182
- Filed: 2015-05-19
- Published: 2015-11-26
- Granted: 2016-12-13
- Earliest claimed: 2014-05-22
- Assignees: Avision Inc.
- Applicants: Avision Inc.
- Inventors: Thomas Sheng; Ku-Ming Chen
- Web page: https://patentgrep.com/patent/US9521288B2

## CPC

- H04N 1/1008: {with sub-scanning by translatory movement of the picture-bearing surface}
- H04N 1/0057: {Conveying sheets before or after scanning (arrangements for conveying sheets as part of the scanning operation H04N1/04 and subgroups)}
- H04N 1/00726: {Other properties of the sheet, e.g. curvature or reflectivity}
- H04N 1/02815: {Means for illuminating the original, not specific to a particular type of pick-up head}
- H04N 1/40: Picture signal circuits (H04N1/387 takes precedence)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A sheet-fed scanner comprising a scan channel, a feeding unit, a transmitting unit, a background sheet, a background light source and a scan module is provided. The feeding unit is disposed at an inlet of the scan channel for feeding a document. The transmitting unit transmits the document to pass through the scan channel. The background sheet is disposed on a side of the scan channel, and has a first surface and a second surface. The first surface faces towards the scan channel. The background light source faces towards the second surface to provide an intermittent light signal to the background sheet, so that the background sheet correspondingly displays an intermittent variation background image on the first surface. The scan module is disposed on another side of the scan channel, and captures a document image of a document and the intermittent variation background image to generate scan data accordingly.

## Claims

### Claim 1

A sheet-fed scanner, comprising:
a scan channel;
a feeding unit disposed at an inlet of the scan channel for feeding a document;
a transmitting unit disposed in the scan channel for transmitting the document to pass through the scan channel;
a background sheet disposed on a side of the scan channel and having a first surface facing towards the scan channel and a second surface;
a background light source facing towards the second surface to provide an intermittent light signal to the background sheet, which correspondingly displays an intermittent variation background image on the first surface; and
a scan module disposed on another side of the scan channel, wherein when the document passes through the scan channel between the scan module and the background sheet, the scan module captures a document image of the document and the intermittent variation background image to generate scan data.

### Claim 2 (depends on 1)

The sheet-fed scanner according to claim 1, further comprising a processor which connects to the scan module to receive the scan data, wherein the processor comprises:
a regulator connected to the background light source for controlling a variation cycle of the intermittent light signal;
a storage unit for storing a background data corresponding to the variation cycle; and
an identification unit for identifying the document image from the scan data according to the background data stored in the storage unit.

### Claim 3 (depends on 2)

The sheet-fed scanner according to claim 2, wherein the identification unit further identifies a boundary of the document image and determines a size of the document image.

### Claim 4 (depends on 2)

The sheet-fed scanner according to claim 2, wherein the processor further comprises an image cropping unit which crops the document image of the scan data.

### Claim 5 (depends on 1)

The sheet-fed scanner according to claim 1, wherein the intermittent variation image is displayed by one of an alternating black and white image, an alternating black, gray and white image, an alternating black and gray image and an alternating gray and white image.

### Claim 6 (depends on 1)

The sheet-fed scanner according to claim 1, wherein the background sheet is a translucent sheet treated with surface atomization.

### Claim 7 (depends on 1)

The sheet-fed scanner according to claim 1, wherein the background sheet is a trans-reflective sheet.

### Claim 8 (depends on 1)

The sheet-fed scanner according to claim 1, wherein the background sheet is a translucent sheet containing emulsified composition.

### Claim 9 (depends on 1)

The sheet-fed scanner according to claim 1, wherein the background light source is a light emitting diode (LED).

### Claim 10

An image scanning method of a sheet-fed scanner, wherein the scanner comprises a scan channel, a background sheet, a background light source and a scan module, the background sheet is disposed on a side of the scan channel, the image scanning method comprising:
providing an intermittent light signal to the background sheet by the background light source, and the background sheet correspondingly displaying an intermittent variation background image; and
having a document passed through the scan channel, so that a document image of the document and the intermittent variation background image are captured by the scan module to generate scan data.

### Claim 11 (depends on 10)

The method according to claim 10, wherein:
the scanner further comprises a processor, which receives the scan data and identifies the document image from the scan data.

### Claim 12 (depends on 11)

The method according to claim 11, wherein the processor further comprises a regulator, a storage unit and an identification unit, and the method further comprises:
controlling a variation cycle of the intermittent light signal by the regulator;
storing a background data corresponding to the variation cycle to the storage unit; and
identifying the document image from the scan data by the identification unit according to the background data stored in the storage unit.

### Claim 13 (depends on 12)

The method according to claim 12, wherein the step of identifying the document image further comprises identifying a boundary of the document image and determining a size of the document image.

### Claim 14 (depends on 13)

The method according to claim 13, further comprising:
cropping the document image of the scan data.

### Claim 15 (depends on 10)

The method according to claim 10, wherein the intermittent variation background image is displayed by one of an alternating black and white image, an alternating black, gray and white image, an alternating black and gray image and an alternating gray and white image.