JPH07113949B2 - Optical scanning device - Google Patents
Optical scanning deviceInfo
- Publication number
- JPH07113949B2 JPH07113949B2 JP1029299A JP2929989A JPH07113949B2 JP H07113949 B2 JPH07113949 B2 JP H07113949B2 JP 1029299 A JP1029299 A JP 1029299A JP 2929989 A JP2929989 A JP 2929989A JP H07113949 B2 JPH07113949 B2 JP H07113949B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- video signals
- semiconductor laser
- receiving
- photoelectric conversion
- 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.)
- Expired - Fee Related
Links
Landscapes
- Mechanical Optical Scanning Systems (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、光走査装置、特にスーパーマーケット等で用
いられている物流およびPOS（ポイントオブセール）用
バーコードリーダのスキャナの回路構成に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device, and more particularly to a circuit configuration of a scanner of a bar code reader for physical distribution and POS (point of sale) used in supermarkets and the like.
（従来技術） 従来、POS用バーコードリーダとしては、第２図に示す
ように、各々単一の光源50、集光系51、孔あきミラー5
2、偏向素子53、パターン形成兼受光光学系54、光電変
換素子56、ビデオ増幅器57、およびデコード回路58で構
成した方式かまたは第３図に示すように、単一レーザ発
振器70の出力光を半透明ミラー71で２分割し、それぞれ
集光系72,73および孔あきミラー74を通して１個の偏向
素子75と１群の走査パターン形成用光学系79で高密度の
走査線80を作り、一対の光電変換素子82,85、およびビ
デオ増幅器83,86および信号前処理部84,87からなる受光
部で必要な二値化ビデオ信号を得る方式となっていた。
なお55,81はそれぞれ被読取対象物である。(Prior Art) Conventionally, as a POS bar code reader, as shown in FIG. 2, a single light source 50, a condensing system 51, and a perforated mirror 5 are provided.
2, a deflection element 53, a pattern forming / light receiving optical system 54, a photoelectric conversion element 56, a video amplifier 57, and a decoding circuit 58, or the output light of a single laser oscillator 70 as shown in FIG. A semi-transparent mirror 71 divides the beam into two parts, and a high-density scanning line 80 is formed by one deflecting element 75 and a group of scanning pattern forming optical system 79 through focusing systems 72, 73 and a perforated mirror 74, respectively. The photoelectric conversion elements 82 and 85, the video amplifiers 83 and 86, and the light receiving section including the signal preprocessing sections 84 and 87 obtain a necessary binarized video signal.
Note that 55 and 81 are objects to be read.
（発明が解決しようとする課題） 上述した従来の方式は、各々の問題点があり、例えば第
２図の方式では機器構成は簡単であるものの走査パター
ンが簡単で走査回数に限界があるため、読取性能面で読
取率の低下する領域が生ずるのを避けられない。また第
３図の方式では第２図の方式の欠点を解決して読取性能
の向上を図っているものの、２つの偏向・受講系を有す
るため原価高となり、更に部品点数増加による信頼性の
低下が避けられないという問題があった。(Problems to be Solved by the Invention) The above-described conventional methods have their respective problems. For example, in the method of FIG. 2, the device configuration is simple, but the scanning pattern is simple and the number of scans is limited. In terms of reading performance, it is inevitable that there will be a region where the reading rate will decrease. Although the method of FIG. 3 solves the drawbacks of the method of FIG. 2 to improve the reading performance, it has two deflection / training systems, resulting in higher costs and lower reliability due to an increase in the number of parts. There was a problem that was inevitable.
（課題を解決するための手段） そこで本発明は、従来技術の読取性能を改善しようとす
るもので、レーザ光源として複数の半導体レーザを使用
し、該半導体レーザを順次切り換えながら励起する駆動
回路と、反射光を電気信号に変換する単一の光電変換素
子と、前置増幅器と前記前置増幅器の出力を半導体レー
ザ切換駆動信号によって同期をとりながら分離するチョ
ッパ回路とを有し、各々の半導体レーザに対応した信号
を得るようにしたものである。この場合、切換周波数と
して映像信号帯域の復元に必要なサンプリング周波数以
上に選ぶ必要がある。(Means for Solving the Problem) Therefore, the present invention is intended to improve the reading performance of the prior art, and uses a plurality of semiconductor lasers as a laser light source, and a drive circuit for exciting the semiconductor lasers while sequentially switching the semiconductor lasers. , A single photoelectric conversion element for converting the reflected light into an electric signal, and a preamplifier and a chopper circuit for separating the output of the preamplifier in synchronization with a semiconductor laser switching drive signal. The signal corresponding to the laser is obtained. In this case, it is necessary to select a switching frequency that is higher than the sampling frequency required to restore the video signal band.
本発明によれば、複数個の半導体レーザ光源およびその
駆動回路と、前記半導体レーザ光源を順次切り換え駆動
するための変調信号発生器と、これらのレーザビームを
受けて該ビームを偏向し受光する１つの走査手段と、前
記走査手段からの受光信号を電気信号に変換して出力す
る光電変換素子と、前記光電変換素子の出力波形を増幅
する前置増幅器と、前記前置増幅器出力を前記変調信号
発生器の変調信号により分離し、複数のビデオ信号とす
るチョッパ回路と、前記複数のビデオ信号の各々を検波
してその包絡線をとった複数のビデオ信号を出力する検
波回路とを有し、前記各検波回路のビデオ信号を読取信
号として読取情報認識処理部へ送出するようにした光走
査装置が提供される。According to the present invention, a plurality of semiconductor laser light sources and a driving circuit thereof, a modulation signal generator for sequentially switching and driving the semiconductor laser light sources, a laser beam for receiving these laser beams, and deflecting and receiving the beams 1 Two scanning means, a photoelectric conversion element for converting a light reception signal from the scanning means into an electric signal and outputting the electric signal, a preamplifier for amplifying an output waveform of the photoelectric conversion element, and a modulation signal for the preamplifier output. Separated by a modulation signal of a generator, a chopper circuit for making a plurality of video signals, and a detection circuit for detecting each of the plurality of video signals and outputting a plurality of video signals whose envelope is taken, There is provided an optical scanning device in which the video signal of each of the detection circuits is sent as a read signal to the read information recognition processing section.
（実施例） 次に、本発明を実施例について図面を参照して説明す
る。(Example) Next, an example of the present invention will be described with reference to the drawings.
第１図（ａ）は本発明の１実施例のブロック構成を示す
図である。なおここでは半導体レーザ光源を２個使った
例で説明する。変調信号発生器１は極性の異なる２種類
の変調信号を出力し、同時に同期用に1a,1bとして変調
信号と同じ波形を出力する。この変調信号を受けて駆動
回路２により可視光半導体レーザ光源４が、また駆動回
路３により可視光半導体レーザ光源５が駆動され、各々
第１図（ｂ）のタイムチャート図における（３），
（４）なる波形で示されるレーザビーム放射が得られ
る。各々のレーザビームは孔あきミラー６を通り回転鏡
７の回転に伴なって偏向され、各々走査線8,9を生ず
る。被読取対象物10は異なった部分（第１図（ｂ）のタ
イムチャートの10,10′）を走査され、散乱された反射
光は送光と逆の方向をたどり、孔あきミラー６で方向変
換され、集光系11を経由して光電変換素子12で電気信号
に変換され、前置増幅器13で増幅される。前置増幅器の
出力はチョッパ回路14で同期信号1aおよび1bにより分離
され、第１図（ｂ）のチャートの（６），（７）で示さ
れる２つの出力信号N1,N2が各走査線8,9に対応して出力
される。これらの信号を検波回路15,16を通して包絡線
を取ると、第１図（ｂ）のタイムチャートの（８），
（９）で示すビデオ信号17,18が得られる。これらのビ
デオ信号は、走査線8,9によって被読取対象物10を２つ
の独立した走査系で得られるビデオ信号と同等である。FIG. 1 (a) is a diagram showing a block configuration of an embodiment of the present invention. Here, an example using two semiconductor laser light sources will be described. The modulation signal generator 1 outputs two types of modulation signals having different polarities, and simultaneously outputs the same waveform as the modulation signal as 1a and 1b for synchronization. Receiving this modulation signal, the drive circuit 2 drives the visible light semiconductor laser light source 4 and the drive circuit 3 drives the visible light semiconductor laser light source 5, respectively, and (3) in the time chart of FIG. 1 (b),
The laser beam emission shown by the waveform (4) is obtained. Each laser beam passes through the perforated mirror 6 and is deflected by the rotation of the rotating mirror 7 to generate scanning lines 8 and 9, respectively. The object 10 to be read is scanned at different portions (10, 10 'in the time chart of FIG. 1 (b)), and the scattered reflected light follows the direction opposite to that of the transmitted light and is directed by the perforated mirror 6. It is converted, converted into an electric signal by the photoelectric conversion element 12 via the light converging system 11, and amplified by the preamplifier 13. The output of the preamplifier is separated by the sync signals 1a and 1b in the chopper circuit 14, and the two output signals N 1 and N 2 shown in (6) and (7) of the chart of FIG. It is output corresponding to lines 8 and 9. Taking envelopes of these signals through the detection circuits 15 and 16, (8) of the time chart of FIG. 1 (b),
The video signals 17 and 18 shown in (9) are obtained. These video signals are equivalent to the video signals obtained by the scanning lines 8 and 9 on the object 10 to be read by two independent scanning systems.
（発明の効果） 以上説明したように本発明は、複数個の半導体レーザ光
源を同期をとりながら駆動し、受信側で同期検波で分離
することにより、簡単な構成で複数の走査系による走査
と同様の効果が得られるので、単一の光源では限界があ
った走査回数の向上、走査パターンの高密度化が用意に
実現可能となる。更に各々の半導体レーザ光源は交互に
駆動されるので累積動作時間の短縮が可能となり長寿命
化も実現出来る。また複数の走査パターンを重ねれば同
じパターンで走査回数を増加させることが可能であり、
各々の光源の空間配置を換えることにより走査パターン
の高密度化が可能となる効果がある。(Effects of the Invention) As described above, according to the present invention, a plurality of semiconductor laser light sources are driven in synchronization with each other, and synchronous detection is performed on the receiving side to separate them. Since the same effect can be obtained, it is possible to easily realize the increase in the number of scans and the increase in the density of the scan pattern, which are limited by the single light source. Further, since the respective semiconductor laser light sources are driven alternately, the cumulative operation time can be shortened and the life can be extended. It is also possible to increase the number of scans with the same pattern by overlapping multiple scan patterns.
By changing the spatial arrangement of the respective light sources, there is an effect that the density of the scanning pattern can be increased.
第１図（ａ）は本発明の実施例に係る光走査装置のスキ
ャン部のブロック図、第１図（ｂ）は第１図（ａ）の実
施例における構成各部の動作のタイムチャートを示す
図、第２図および第３図は従来のバーコードリーダのス
キャン部のブロック図である。 １……変調信号発生器、2,3……駆動回路、 4,5……半導体レーザー光源、６……孔あきミラー、 ７……回転鏡、12……光電変換素子、 13……前置増幅器、14……チョッパ回路、 15,16……検波回路。FIG. 1 (a) is a block diagram of a scanning unit of an optical scanning device according to an embodiment of the present invention, and FIG. 1 (b) is a time chart of the operation of each component in the embodiment of FIG. 1 (a). FIG. 2, FIG. 3 and FIG. 3 are block diagrams of the scanning unit of the conventional bar code reader. 1 ... Modulation signal generator, 2, 3 ... Driving circuit, 4, 5 ... Semiconductor laser light source, 6 ... Perforated mirror, 7 ... Rotating mirror, 12 ... Photoelectric conversion element, 13 ... Front Amplifier, 14 …… Chopper circuit, 15,16 …… Detection circuit.
Claims (1)
回路と、前記半導体レーザ光源を順次切り換え駆動する
ための変調信号発生器と、これらのレーザビームを受け
て該ビームを偏向し受光する１つの走査手段と、前記走
査手段からの受光信号を電気信号に変換して出力する光
電変換素子と、前記光電変換素子の出力波形を増幅する
前置増幅器と、前記前置増幅器の出力を前記変調信号発
生器の変調信号により分離し、複数のビデオ信号とする
チョッパ回路と、前記複数のビデオ信号の各々を検波し
てその包絡線をとった複数のビデオ信号を出力する検波
回路とを有し、前記各検波回路のビデオ信号を読取信号
として読取情報認識処理部へ送出するようにしたことを
特徴とする光走査装置。1. A plurality of semiconductor laser light sources and a drive circuit thereof, a modulation signal generator for sequentially switching and driving the semiconductor laser light sources, and one for receiving these laser beams and deflecting and receiving the beams. Scanning means, a photoelectric conversion element for converting a light receiving signal from the scanning means into an electric signal and outputting the electric signal, a preamplifier for amplifying an output waveform of the photoelectric conversion element, and an output of the preamplifier for the modulation signal. Separated by a modulation signal of a generator, a chopper circuit for making a plurality of video signals, and a detection circuit for detecting each of the plurality of video signals and outputting a plurality of video signals whose envelope is taken, An optical scanning device, wherein a video signal of each of the detection circuits is sent as a read signal to a read information recognition processing section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1029299A JPH07113949B2 (en) | 1989-02-08 | 1989-02-08 | Optical scanning device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1029299A JPH07113949B2 (en) | 1989-02-08 | 1989-02-08 | Optical scanning device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02207385A JPH02207385A (en) | 1990-08-17 |
| JPH07113949B2 true JPH07113949B2 (en) | 1995-12-06 |
Family
ID=12272360
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1029299A Expired - Fee Related JPH07113949B2 (en) | 1989-02-08 | 1989-02-08 | Optical scanning device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07113949B2 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61201382A (en) * | 1985-03-04 | 1986-09-06 | Ricoh Co Ltd | Optical reader |
| JPS6324379A (en) * | 1986-07-16 | 1988-02-01 | Tokyo Electric Co Ltd | Optical reader |
-
1989
- 1989-02-08 JP JP1029299A patent/JPH07113949B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61201382A (en) * | 1985-03-04 | 1986-09-06 | Ricoh Co Ltd | Optical reader |
| JPS6324379A (en) * | 1986-07-16 | 1988-02-01 | Tokyo Electric Co Ltd | Optical reader |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02207385A (en) | 1990-08-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |