JPH0358180A - Bar code reader - Google Patents

Bar code reader

Info

Publication number
JPH0358180A
JPH0358180A JP1196123A JP19612389A JPH0358180A JP H0358180 A JPH0358180 A JP H0358180A JP 1196123 A JP1196123 A JP 1196123A JP 19612389 A JP19612389 A JP 19612389A JP H0358180 A JPH0358180 A JP H0358180A
Authority
JP
Japan
Prior art keywords
signal
light reception
light
output
reception signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP1196123A
Other languages
Japanese (ja)
Inventor
Tsukasa Fujita
司 藤田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Keyence Corp
Original Assignee
Keyence Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Keyence Corp filed Critical Keyence Corp
Priority to JP1196123A priority Critical patent/JPH0358180A/en
Publication of JPH0358180A publication Critical patent/JPH0358180A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To prevent detection of an erroneous signal by comparing a light reception signal and a signal obtained by inverting its waveform with each other to output a bar code signal. CONSTITUTION:A bias signal G is generated from a light reception signal A by a bias circuit consisting of a lower envelope circuit 5, an integrating circuit, or the like and is added to the light reception signal A to convert the light reception signal A showing tendency to output reduction to a signal H showing tendency to output rise. Meanwhile, the waveform of the light reception signal A is inverted by an amplifier 7 of -1 or proper magnification to generate an inverted signal F showing tendency to output rise. The light reception signal H after addition and the inverted light reception signal F which are generated by this processing are compared with each other by comparator 8 to output a bar code signal E. That is, the signal H generated by adding the bias signal G to the light reception signal A and the signal F obtained by inverting the light reception signal A can be compared with each other in the same level because both signals show the same tendency to output rise. Thus, an influence of a high-pass filter 3 in the circuit is compensated to surely detect the bar code signal.

Description

【発明の詳細な説明】 （産業上の利用分野）、 本発明はバーコードへ向かってレーザー光を照射し、バ
ーコードからの反射光を受光して処理しバーコード信号
を出力するバーコードリーグに関するものである。Detailed Description of the Invention (Industrial Application Field) The present invention is directed to a barcode league that irradiates a laser beam toward a barcode, receives and processes the reflected light from the barcode, and outputs a barcode signal. It is related to.

（従来の技術） 従来バーコードからの反射光の処理について、第５図、
第６図ａ，ｂに示すバーコードリーグが提案されている
（特開昭５　０−４　８　８　３　６）。(Prior art) Fig. 5 shows the processing of reflected light from conventional barcodes.
The barcode league shown in FIGS. 6a and 6b has been proposed (Japanese Patent Application Laid-Open No. 50-488-36).

これはバーコードからの反射光を受光素子（１）によっ
て受光してバーコードの明暗に対応した電気信号を出力
し、前置増幅器（２）、ハイバスフィルタ（３）を通し
てミ信号を増幅し、周囲の明るさ線回路（ｌＯ）と下部
包絡線回路（５）に入力する。The light receiving element (1) receives the reflected light from the barcode, outputs an electrical signal corresponding to the brightness of the barcode, and amplifies the signal through a preamplifier (2) and a high-pass filter (3). , to the ambient brightness line circuit (lO) and the lower envelope circuit (5).

受光信号Ａから上部及び下部包絡線信号Ｂ，　Ｃを形成
し、これを抵抗分割（１１）　Ｌ，て、波形振幅の中央
レベルを表わす基準信号Ｄを形成し、該基準信号Ｄに対
する受光信号Ａの大小を比較してバーコード信号Ｅを得
るものである。Upper and lower envelope signals B and C are formed from the received light signal A, and these are divided by resistance (11) to form a reference signal D representing the center level of the waveform amplitude, and the received light signal A is divided into the received light signal A with respect to the reference signal D. The barcode signal E is obtained by comparing the magnitudes of .

（解決すべき問題点１） ところでバーコードを付した物品と受光素子の間隔は必
ずしも一定しておらず、作業者の操作によってバラ付く
ことが常である。(Problem to be Solved 1) By the way, the distance between the barcoded article and the light receiving element is not necessarily constant and often varies depending on the operator's operations.

受光素子が受ける反射光の強さは、物品との距離の自乗
に反比例して弱まるから、物品が遠い状況でもバーコー
ドを確実に読みとるには増幅器（２）の出力を高めてお
く必要がある。しかし後続の物品が受光素子（１）に接
近した場合には、増幅器（２）の出力は飽和するから、
誤動作を起す原因となる。The intensity of the reflected light received by the light receiving element weakens in inverse proportion to the square of the distance from the object, so it is necessary to increase the output of the amplifier (2) in order to reliably read barcodes even when the object is far away. . However, if a subsequent article approaches the light receiving element (1), the output of the amplifier (2) will be saturated.
This may cause malfunction.

（問題点を解決するための手段１）(Means to solve the problem 1)

Claims (1)

【特許請求の範囲】 ［１］バーコードからの反射光に対応した受光信号Ａを
出力する受光素子（１）と、 該受光信号Ａの波形を反転した波形Ｆを形成する反転回
路（７）と、 受光素子が出力する受光信号Ａと、該受光信号Ａの波形
を反転した信号Ｆとを比較して、バーコード信号Ｅを出
力する比較器（８） とを具備したバーコードリーダ。 ［２］バーコードからの反射光に対応した受光信号Ａを
出力する受光素子（１）と、該受光素子が出力する受光
信号Ａの包絡線或いは積分値を形成し、これを反転した
出力Ｇを形成するバイアス回路と、 受光素子が出力する受光信号Ａとバイアス回路の出力信
号Ｇとを加算する加算器（４）と、受光素子からの受光
信号の波形を反転する反転回路（７）と、 前記加算器（４）及び反転回路（７）の夫々の出力信号
Ｈ及びＦを比較して、バーコード信号を出力する比較器
（８） とを具備したバーコードリーダ。[Scope of Claims] [1] A light-receiving element (1) that outputs a light-receiving signal A corresponding to reflected light from a barcode, and an inverting circuit (7) that forms a waveform F that is an inversion of the waveform of the light-receiving signal A. A barcode reader comprising: a comparator (8) that compares a light reception signal A output by a light receiving element with a signal F obtained by inverting the waveform of the light reception signal A and outputs a barcode signal E. [2] A light-receiving element (1) that outputs a light-receiving signal A corresponding to the reflected light from the barcode, and an output G that forms an envelope or an integral value of the light-receiving signal A output by the light-receiving element and inverts this. an adder (4) that adds the light-receiving signal A output from the light-receiving element and the output signal G of the bias circuit; and an inversion circuit (7) that inverts the waveform of the light-receiving signal from the light-receiving element. , a comparator (8) that compares the output signals H and F of the adder (4) and the inversion circuit (7) and outputs a barcode signal.
JP1196123A 1989-07-26 1989-07-26 Bar code reader Pending JPH0358180A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1196123A JPH0358180A (en) 1989-07-26 1989-07-26 Bar code reader

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1196123A JPH0358180A (en) 1989-07-26 1989-07-26 Bar code reader

Publications (1)

Publication Number Publication Date
JPH0358180A true JPH0358180A (en) 1991-03-13

Family

ID=16352626

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1196123A Pending JPH0358180A (en) 1989-07-26 1989-07-26 Bar code reader

Country Status (1)

Country Link
JP (1) JPH0358180A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04507472A (en) * 1990-09-19 1992-12-24 マース，インコーポレィテッド Barcode scanning method and device under adverse scanning conditions
US6834806B2 (en) * 2000-11-14 2004-12-28 Datalogic S.P.A. Method for locating the transitions between the elements of a bar code

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6459574A (en) * 1987-08-31 1989-03-07 Matsushita Electric Ind Co Ltd Bar code detecting device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6459574A (en) * 1987-08-31 1989-03-07 Matsushita Electric Ind Co Ltd Bar code detecting device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04507472A (en) * 1990-09-19 1992-12-24 マース，インコーポレィテッド Barcode scanning method and device under adverse scanning conditions
US6834806B2 (en) * 2000-11-14 2004-12-28 Datalogic S.P.A. Method for locating the transitions between the elements of a bar code

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