# US 5,349,171 A · Bar code reader

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,349,171 A
- Document ID: US5349171A
- Status: Granted
- Kind: A
- Application number: 07/919,906
- Filed: 1992-07-27
- Granted: 1994-09-20
- Earliest claimed: 1991-07-26
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Seiichiro Tamai; Keiichi Kobayashi; Hideki Imai; Takahiro Yamao
- Web page: https://patentgrep.com/patent/US5349171A

## CPC

- G06K 7/10841: {Particularities of the light-sensitive elements (semiconductor devices H10)}
- G06K 7/10851: {Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device (basic electronic circuitry H03)}
- G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS

## Abstract

A bar code reader has a CCD for producing an image signal, an amplifier for amplifying the image signal from the CCD and a digitalizing circuit for changing the image signal to binary signal. The CCD operates with an operating voltage Vcc less than 8 V. The amplifier has first and second operational amplifiers each having one voltage source terminal connected to Vcc of 5 V and the other voltage source terminal connected to ground. Also, the digitalizing circuit has a third operational amplifier having one voltage source terminal connected to Vcc of 5 V and the other voltage source terminal connected to ground.

## Claims

### Claim 1

In a bar code reader having a light source for lighting the bar code, an image sensor for receiving the reflected light from the bar code and producing an image signal, a drive circuit for driving the image sensor, an amplifier for amplifying the image signal, and a digitalizing circuit for digitalizing the amplified image signal and producing a digital signal representing the bar code, an improvement comprising:
said image sensor comprising light receiving elements formed in a CCD array which operates with an operating voltage (Vcc) less than 8 V;
said amplifier comprising first and second operational amplifiers each having one voltage source terminal connected to Vcc of 5 V and the other voltage source terminal connected to ground; and
said digitalizing circuit comprising a third operational amplifier having one voltage source terminal connected to Vcc of 5 V and the other voltage source terminal connected to ground.

### Claim 2

In a bar code reader having a light source for lighting the bar code, an image sensor for receiving the reflected light from the bar code and producing an image signal, a drive circuit for driving the image sensor, an amplifier for amplifying the image signal, and a digitalizing circuit for digitalizing the amplified image signal and producing a digital signal representing the bar code, an improvement comprising:
said image sensor comprising light receiving elements formed in a CCD array which operates with an operating voltage Vcc less than 8 V;
said amplifier comprising first and second operational amplifiers each having one voltage source terminal connected to Vcc of 5 V and the other voltage source terminal connected to ground;
said digitalizing circuit comprising a third operational amplifier having one voltage source terminal connected to Vcc of 5 V and the other voltage source terminal connected to ground; and
amplitude control means for controlling the amplitude of the amplified image signal, said amplitude control means comprising (i) a fourth operational amplifier coupled to said amplifier, and (ii) means to which said fourth operational amplifier is coupled for changing an amplification rate of said fourth operational amplifier as a function of a bar code detection signal.

### Claim 3 (depends on 1)

A bar code reader as claimed in claim 1, wherein said digitalizing circuit is reset after each scanning operation of said image sensor.

### Claim 4 (depends on 1)

A bar code reader as claimed in claim 1, further comprising an amplitude control means for controlling the amplitude of the signal produced from said amplifier.

### Claim 5 (depends on 1)

A bar code reader as claimed in claim 1, further comprising an offset level control means for controlling the offset level of the signal produced from said amplifier.

### Claim 6 (depends on 1)

A bar code reader as claimed in claim 1, further comprising a processor for decoding the digital signal.

### Claim 7 (depends on 6)

A bar code reader as claimed in claim 6, further comprising a data communication system for transmitting the decoded digital signal.

### Claim 8 (depends on 7)

A bar code reader as claimed in claim 7, wherein said data communication system is a wireless system comprising a photodiode.

### Claim 9 (depends on 7)

A bar code reader as claimed in claim 7, wherein said data communication system is a wireless system comprising a wave generator.