JPH04130410A - Scanning optical system - Google Patents

Scanning optical system

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Publication number
JPH04130410A
JPH04130410A JP25261290A JP25261290A JPH04130410A JP H04130410 A JPH04130410 A JP H04130410A JP 25261290 A JP25261290 A JP 25261290A JP 25261290 A JP25261290 A JP 25261290A JP H04130410 A JPH04130410 A JP H04130410A
Authority
JP
Japan
Prior art keywords
laser
light
reflection mirror
position detection
returned
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
JP25261290A
Other languages
Japanese (ja)
Inventor
Hideaki Abe
英昭 阿部
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.)
NEC Corp
Original Assignee
NEC 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 NEC Corp filed Critical NEC Corp
Priority to JP25261290A priority Critical patent/JPH04130410A/en
Publication of JPH04130410A publication Critical patent/JPH04130410A/en
Pending legal-status Critical Current

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  • Mechanical Optical Scanning Systems (AREA)

Abstract

PURPOSE:To accomplish accurate position detection by returning reflected light from a reflection mirror disposed in a position detection means to a semiconductor laser light beam source. CONSTITUTION:Incident light 11 on the reflection mirror 12a out of laser light beam which scans a photosensitive body 1 is vertically reflected, advances in a reverse direction through a path which it traces hitherto, and is returned to a semiconductor laser 9. Since the laser 9 and the reflection mirror 12a are located at optically conjugate positions, special accuracy other than the accuracy of an angle around an axis vertical to the scanning plane of the reflection mirror is not needed. In the case that the light which is emitted by the laser 9 itself is returned to the laser 9 in the middle of exciting and emitting light, the interference phenomenon of the light is caused in the laser 9 and the fluctuation of optical output occurs. When the optical output is to be kept constant, the change of a driving current occurs. By grasping this change, it is detected when the light of its own is returned. Thus, the accurate position detection is accomplished.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は走査光学系に関し、特にレーザブリタに用いら
れる等連子面走査光学系に関する。
DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a scanning optical system, and more particularly to an isotram surface scanning optical system used in a laser printer.

〔従来の技術〕[Conventional technology]

ン 従来、この種の走査光学系は、第2図に示すような構成
であった。すなわち、半導体レーザ9の両端から出射さ
れなレーザ光の一方は光パワーセンサ10に入射し、光
パワー検出回路8に電気信号として入力され、レーザ駆
動回路7を制御する信号に変換される。レーザ駆動回路
は半導体レーザ9を駆動する電流を制御し、半導体レー
ザ9の発光時には一定の光出力を得る様にフィードバッ
ク制御される。
Conventionally, this type of scanning optical system has had a configuration as shown in FIG. That is, one of the laser beams emitted from both ends of the semiconductor laser 9 enters the optical power sensor 10, is input as an electrical signal to the optical power detection circuit 8, and is converted into a signal for controlling the laser drive circuit 7. The laser drive circuit controls the current that drives the semiconductor laser 9, and performs feedback control to obtain a constant optical output when the semiconductor laser 9 emits light.

また、半導体レーザ9から出射されたもう一方のレーザ
光は、コリメートレンズ6に入射して平行光に変えられ
、続いてシリンダレンズ5を通り、モータ4で高速回転
するポリゴンミラー3にて偏向走査される。そして、偏
向されたレーザ光はf−θレンズ2にて等速走査する平
面結像光となって感光体1上に照射される。このとき、
走査するレーザ光のうち反射ミラー12への入射光11
は位!検出スリット13の方向に反射する。
The other laser beam emitted from the semiconductor laser 9 enters a collimating lens 6 and is converted into parallel light, then passes through a cylinder lens 5 and is deflected and scanned by a polygon mirror 3 rotated at high speed by a motor 4. be done. Then, the deflected laser light becomes plane imaging light that is scanned at a constant speed by the f-theta lens 2 and is irradiated onto the photoreceptor 1. At this time,
Among the scanning laser beams, incident light 11 on the reflecting mirror 12
Yes! It is reflected in the direction of the detection slit 13.

レーザ光がスリット13から短時間入射した時、光パワ
ーセンサ14から走査タイミング検出回路15に電気信
号が送出され、走査タイミング検出回路15でタイミン
グパルス16を出力する。そして、制御部〈図示せず)
は、このタイミングパルス16に同期させてレーザ駆動
回路7にレーザ○N10 F F信号17を与え、感光
体1上に静電潜像を形成する。
When the laser beam enters from the slit 13 for a short time, an electrical signal is sent from the optical power sensor 14 to the scanning timing detection circuit 15, and the scanning timing detection circuit 15 outputs a timing pulse 16. and a control unit (not shown)
In synchronization with this timing pulse 16, a laser ○N10FF signal 17 is applied to the laser drive circuit 7 to form an electrostatic latent image on the photoreceptor 1.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

従来の走査光学系では、特別な位置検出用のスリット、
光パワーセンサ、タイミング検出回路などを設けなけれ
ば走査位置の検出が不可能であった。また、反射ミラー
とスリットとの光学的な位置関係は、精度を高く保つ必
要がありコストが高くなるという欠点があった。また、
この精度か低いと光パワーセンサに光が入射しなかった
り、温度歪、経時変化などでタイミングパルスを発生で
きなくなり、タイミングが変化してしまう欠点があった
In conventional scanning optics, special position detection slits,
It was impossible to detect the scanning position without providing an optical power sensor, a timing detection circuit, etc. Furthermore, the optical positional relationship between the reflecting mirror and the slit must be maintained with high precision, resulting in an increase in cost. Also,
If this accuracy is low, there is a drawback that light may not enter the optical power sensor, or timing pulses may not be generated due to temperature distortion, changes over time, etc., and the timing may change.

〔課題を解決するための手段〕[Means to solve the problem]

本発明は、半導体レーザ光源と、これから出射されたレ
ーザ光の強度を検出する検出手段と、前記レーザ光を平
行光に変換するレンズと、前記平行光を偏向する走査手
段と、前記走査手段により走査された光束の位置を検出
する位置検出手段とを備えた光学走査系において、前記
位置検出手段に反射ミラーを配設し、前記反射ミラーか
らの反射光を前記半導体レーザ光源に戻すように構成し
たことを特徴とする。
The present invention includes a semiconductor laser light source, a detection means for detecting the intensity of the laser light emitted from the laser light source, a lens for converting the laser light into parallel light, a scanning means for deflecting the parallel light, and the scanning means. An optical scanning system comprising a position detecting means for detecting the position of a scanned light beam, wherein the position detecting means is provided with a reflecting mirror, and the reflected light from the reflecting mirror is returned to the semiconductor laser light source. It is characterized by what it did.

〔実施例〕〔Example〕

次に、本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.

第1図は発明の一実施例を示す構成図である。FIG. 1 is a configuration diagram showing an embodiment of the invention.

第1図において、半導体レーザ9の両端から出射された
レーザ光の一方は光パワーセンサ10に入射し、光パワ
ー検出回路8に電気信号として入力され、レーザ駆動回
路7を制御する信号に変換される。レーザ駆動回路7は
半導体レーザ9を駆動する電流を制御し、半導体レーザ
9の発光時には一定の光出力を得る様にフィードバック
制御される。
In FIG. 1, one of the laser beams emitted from both ends of the semiconductor laser 9 enters the optical power sensor 10, is inputted as an electrical signal to the optical power detection circuit 8, and is converted into a signal for controlling the laser drive circuit 7. Ru. The laser drive circuit 7 controls the current that drives the semiconductor laser 9, and performs feedback control to obtain a constant optical output when the semiconductor laser 9 emits light.

また、半導体レーザ9から出射されたもう一方のレーザ
光は、コリメートレンズ6に入射して平行光に変えられ
、続いてシリンダレンズ5を通り、モータ4で高速回転
するポリゴンミラー3にて偏向走査される。そして、偏
向されたレーザ光はf−θレンズ2にて等速走査する平
面結像光となって感光体1上に照射される。また、位置
検出用の反射ミラー12aは感光体1と同じ像平面上に
設置される。ここで、感光体1上を走査するレーザ光の
うち反射ミラー12aへの入射光11は垂直に反射され
、これまで辿ってきた経路を逆の方向に進み半導体レー
ザ9に戻る。ここで、半導体レーザ9と反射ミラー12
aとは光学的に共役な位置にあるため、反射ミラーの走
査平面に垂直な軸の周辺の角度精度以外は特別な精度を
必要としない。また、反射ミラー12の代りに2つの互
いに直角な対設されたコーナーミラーを用いれば、走査
平面に垂直な軸の周辺の角度は高精度を必要としなくな
る。このような手段により走査されたレーザ光が反射ミ
ラー12aに照射されている間だけレーザ光を半導体レ
ーザ9に戻す。
The other laser beam emitted from the semiconductor laser 9 enters a collimating lens 6 and is converted into parallel light, then passes through a cylinder lens 5 and is deflected and scanned by a polygon mirror 3 rotated at high speed by a motor 4. be done. Then, the deflected laser light becomes plane imaging light that is scanned at a constant speed by the f-theta lens 2 and is irradiated onto the photoreceptor 1. Further, a reflection mirror 12a for position detection is installed on the same image plane as the photoreceptor 1. Here, among the laser beams scanning the photoreceptor 1, the incident light 11 on the reflecting mirror 12a is vertically reflected and travels in the opposite direction along the path that has been followed thus far and returns to the semiconductor laser 9. Here, the semiconductor laser 9 and the reflection mirror 12
Since the position is optically conjugate with a, no special accuracy is required except for the angular accuracy around the axis perpendicular to the scanning plane of the reflecting mirror. Furthermore, if two mutually orthogonal opposed corner mirrors are used instead of the reflecting mirror 12, the angles around the axis perpendicular to the scanning plane do not require high precision. The laser beam scanned by such means is returned to the semiconductor laser 9 only while the reflecting mirror 12a is irradiated with the laser beam.

ところで、半導体レーザ9は励起発光中に自らの発光し
た光を戻すと、光の干渉現象を起こし、光出力の変動を
起こす。そして、光出力を一定に保持しようとすると駆
動電流に変化が生じる。この変化を捉えれば、いつ自ら
の光が戻されたか検出が可能である。あるいは、光パワ
ーセンサ10によっても戻り光の変化を捉えることも可
能であり、この変化を走査位置の検出信号とすることが
できる、光パワー検出回路8aは走査位置検出手段とし
ても機能させタイミングパルス18を出力する。そして
、制御部(図示せず)は、このタイミング18に同期さ
せてレーザ駆動回路7にレーザ○N/○FF信号17を
与え、感光体1上に静電潜像を形成する。
By the way, when the semiconductor laser 9 returns its own emitted light during excitation emission, a light interference phenomenon occurs and the optical output fluctuates. Then, when trying to keep the optical output constant, a change occurs in the drive current. By capturing this change, it is possible to detect when its own light is returned. Alternatively, it is also possible to detect changes in the returned light by the optical power sensor 10, and this change can be used as a scanning position detection signal.The optical power detection circuit 8a also functions as a scanning position detection means and generates timing pulses. Outputs 18. Then, the control section (not shown) provides a laser ○N/○FF signal 17 to the laser drive circuit 7 in synchronization with this timing 18 to form an electrostatic latent image on the photoreceptor 1.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、位置検出のための特別な光センサやス
リットなどを設けることなく、精度の高い位置検出が可
能になり、コストダウンが可能である。また、位置検出
精度の安定性も高いものが可能になるという効果がある
According to the present invention, highly accurate position detection is possible without providing a special optical sensor, slit, etc. for position detection, and cost reduction is possible. Further, there is an effect that it is possible to achieve highly stable position detection accuracy.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の一実施例を示す構成図、第2図は従来
例を示す構成図である。 1・・・感光体、2・・・f−θレンズ、3.1.ポリ
ゴンミラー、4・・・モータ、5・・・シリンダレンズ
、6・・コリメートレンズ、7・・・レーザ駆動回路、
8゜8a・・・光パワー検出回路、9・・半導体レーザ
、10.14・・・光パワーセンサ、11・・入射光、
12.12a・・・反射ミラー、13・・・スリット、
15・・・走査タイミング検出回路、16.18・・・
タイミングパルス、17・・レーザ0N10FF信号。
FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. 1... Photoreceptor, 2... f-theta lens, 3.1. Polygon mirror, 4...Motor, 5...Cylinder lens, 6...Collimating lens, 7...Laser drive circuit,
8゜8a... Optical power detection circuit, 9... Semiconductor laser, 10.14... Optical power sensor, 11... Incident light,
12.12a...Reflection mirror, 13...Slit,
15...Scanning timing detection circuit, 16.18...
Timing pulse, 17...Laser 0N10FF signal.

Claims (1)

【特許請求の範囲】[Claims] 半導体レーザ光源と、これから出射されたレーザ光の強
度を検出する検出手段と、前記レーザ光を平行光に変換
するレンズと、前記平行光を偏向する走査手段と、前記
走査手段により走査された光束の位置を検出する位置検
出手段とを備えた光学走査系において、前記位置検出手
段に反射ミラーを配設し、前記反射ミラーからの反射光
を前記半導体レーザ光源に戻すように構成したことを特
徴とする走査光学系。
A semiconductor laser light source, a detection means for detecting the intensity of the laser light emitted from the laser light source, a lens for converting the laser light into parallel light, a scanning means for deflecting the parallel light, and a light beam scanned by the scanning means. and a position detection means for detecting the position of the optical scanning system, characterized in that a reflecting mirror is disposed in the position detection means, and the reflected light from the reflection mirror is returned to the semiconductor laser light source. scanning optical system.
JP25261290A 1990-09-21 1990-09-21 Scanning optical system Pending JPH04130410A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP25261290A JPH04130410A (en) 1990-09-21 1990-09-21 Scanning optical system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP25261290A JPH04130410A (en) 1990-09-21 1990-09-21 Scanning optical system

Publications (1)

Publication Number Publication Date
JPH04130410A true JPH04130410A (en) 1992-05-01

Family

ID=17239793

Family Applications (1)

Application Number Title Priority Date Filing Date
JP25261290A Pending JPH04130410A (en) 1990-09-21 1990-09-21 Scanning optical system

Country Status (1)

Country Link
JP (1) JPH04130410A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06167662A (en) * 1992-11-30 1994-06-14 Nishimoto Sangyo Kk Exposure controller of electronic processing light and shade photograph reproducing device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0290121A (en) * 1988-09-28 1990-03-29 Hitachi Ltd Optical beam detector

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0290121A (en) * 1988-09-28 1990-03-29 Hitachi Ltd Optical beam detector

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06167662A (en) * 1992-11-30 1994-06-14 Nishimoto Sangyo Kk Exposure controller of electronic processing light and shade photograph reproducing device

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