JPH04186214A - Scanning optical device - Google Patents
Scanning optical deviceInfo
- Publication number
- JPH04186214A JPH04186214A JP31684790A JP31684790A JPH04186214A JP H04186214 A JPH04186214 A JP H04186214A JP 31684790 A JP31684790 A JP 31684790A JP 31684790 A JP31684790 A JP 31684790A JP H04186214 A JPH04186214 A JP H04186214A
- Authority
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- Prior art keywords
- light
- light source
- scanning
- source means
- scanned
- Prior art date
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Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 49
- 238000003384 imaging method Methods 0.000 claims description 18
- 230000004907 flux Effects 0.000 abstract 3
- 238000010586 diagram Methods 0.000 description 3
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 108091008695 photoreceptors Proteins 0.000 description 1
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- Mechanical Optical Scanning Systems (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は走査光学装置に関し、特に感光体や静電記録体
等の像担持体である被走査面上を光変調された光束、例
えばレーザー光束で走査することにより画像形成するよ
うにした例えば電子写真プロセスを有するレーザーど−
ムプリンタやカラーレーザーヒ゛−ムプリンター、マル
チカラーレーザービームプリンター等の装置に好適な走
査光学装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a scanning optical device, and in particular to a scanning optical device, in particular a light beam modulated on a scanned surface that is an image bearing member such as a photoreceptor or an electrostatic recording medium, such as a laser beam. For example, a laser device that uses an electrophotographic process to form an image by scanning with a beam of light.
The present invention relates to a scanning optical device suitable for devices such as color printers, color laser beam printers, and multicolor laser beam printers.
（従来の技術）
従来、この種の走査光学装置においては、例えば特公昭
６２−３６２１０号等に記載されているように光源平段
から光変調された光束を回転多面鏡の反射面で偏向反射
させた後走査レンズ系を介して被走査面上に導光して光
走査している。(Prior Art) Conventionally, in this type of scanning optical device, as described in Japanese Patent Publication No. 62-36210, etc., a light beam modulated from a light source is deflected and reflected by a reflecting surface of a rotating polygon mirror. After that, the light is guided onto the surface to be scanned through a scanning lens system for optical scanning.
第４図は従来の走査光学装置の要部概略図である。FIG. 4 is a schematic diagram of the main parts of a conventional scanning optical device.
第４図に於いて半導体レーザー等から成る光源手段１よ
り出射した光束をコリメーターレンズ１１により平行光
束とし、副走査方向にのみ屈折力を持つシリンドリカル
レンズ１２て集光し回転多面鏡等から成る光偏向器３の
偏向反射面３ａへ線状に入射させている。In FIG. 4, a light beam emitted from a light source means 1 consisting of a semiconductor laser or the like is made into a parallel beam by a collimator lens 11, and is condensed by a cylindrical lens 12 having refractive power only in the sub-scanning direction, which is composed of a rotating polygon mirror or the like. The light is linearly incident on the deflection reflection surface 3a of the light deflector 3.
光偏向器３はモータ等の駆動手段４により矢印５の方向
に等速回転している。該偏向反射面３ａて反射偏向させ
た光束を球面レンズと直交する２方向で屈折力か異なる
トーリック面を存するトーリックレンズとによって構成
される結像レンズ６により集光し感光ドラムより成る被
走査面７上に導光しスポットを形成する。そして前記偏
向器３を回転軸５ａを中心に矢印５方向に回転させるこ
とにより被走査面７上を等速に光走査する。The optical deflector 3 is rotated at a constant speed in the direction of an arrow 5 by a driving means 4 such as a motor. The light beam reflected and deflected by the deflection reflection surface 3a is focused by an imaging lens 6 constituted by a spherical lens and a toric lens having a toric surface with different refractive powers in two orthogonal directions, and then condensed onto a scanned surface made of a photosensitive drum. 7 to form a spot. By rotating the deflector 3 in the direction of the arrow 5 about the rotation axis 5a, the surface to be scanned 7 is scanned with light at a constant speed.
（発明か解決しようとする問題点）
従来の走査光学装置ては感光トラム７の感度か低かった
為に、光源手段１からの光束のカップリング効率を上げ
る為に高いＮＡのコリメーターレンズを用いていた。こ
の為コリメーターレンズ１１の焦点深度が狭くなり、光
源手段１とコリメーターレンズ１１とのピント調整か難
しくなる傾向かあった。(Problem to be solved by the invention) Since the sensitivity of the photosensitive tram 7 in the conventional scanning optical device was low, a collimator lens with a high NA was used to increase the coupling efficiency of the light beam from the light source means 1. was. For this reason, the depth of focus of the collimator lens 11 becomes narrower, which tends to make it difficult to adjust the focus between the light source means 1 and the collimator lens 11.
これに対して近年感光ドラムの感度か向上した為、高い
ＮＡのコリメーターレンズを用いる必要かなくなってき
た。On the other hand, as the sensitivity of photosensitive drums has improved in recent years, it is no longer necessary to use a high NA collimator lens.
しかしなからコリメーターレンズを用いて光源手段から
の光束を所定の光束径の良好なる平行光束とするにはコ
リメーターレンズと光源手段との間隔をある程度拡げる
必要かあった。この為、走査系か大型化してくるという
問題点かあった。However, in order to convert the light beam from the light source means into a well-parallel light beam having a predetermined diameter using the collimator lens, it is necessary to increase the distance between the collimator lens and the light source means to some extent. For this reason, there was a problem in that the scanning system became larger.
この他コリメーターレンズを用いる場合にはコリメータ
ーレンズと光源手段との相対的な位置合わせ、即ちコリ
メーターレンズの光軸に対して垂直な面内に光源手段の
光射出面を精度良く位置させねばならないといった問題
点かあった。In addition, when using a collimator lens, the relative positioning of the collimator lens and the light source means must be adjusted, that is, the light exit surface of the light source means must be accurately positioned within a plane perpendicular to the optical axis of the collimator lens. There was a problem that it was necessary.
本発明は光源手段と光偏向器との間に適切なる開口径を
有する絞りを配置することにより、コリメーターレンズ
を用いずに走査系全体の小型化を図りつつ簡易な構成に
より被走査面上を高精度に光走査することができる走査
光学装置の提供を目的とする。By arranging a diaphragm with an appropriate aperture diameter between the light source means and the optical deflector, the present invention aims to miniaturize the entire scanning system without using a collimator lens, and with a simple configuration, the surface to be scanned can be easily An object of the present invention is to provide a scanning optical device that can perform optical scanning with high precision.
（問題点を解決するための手段）
本発明の走査光学装置は、光源手段からの光束を絞りを
介して光偏向器で偏向させた後、結像レンズを介して被
走査面上に導光し、該光偏向器を回動させることにより
、該被走査面上を主走査方向に光走査する際、該光源手
段から放射される光束の主波長をえ、該光源手段の光射
出面から該絞りまでの距離をｌ、該絞りの主走査断面内
における開口径なりとしたとき
なる条件を満足するように各要素を設定したことを特徴
としている。(Means for Solving the Problems) The scanning optical device of the present invention deflects a light beam from a light source means through an aperture with an optical deflector, and then guides the light onto a surface to be scanned through an imaging lens. By rotating the optical deflector, when scanning the surface to be scanned with light in the main scanning direction, the main wavelength of the light beam emitted from the light source means is adjusted, and the main wavelength of the light beam emitted from the light emitting surface of the light source means is adjusted. The present invention is characterized in that each element is set so as to satisfy the condition where the distance to the diaphragm is l and the aperture diameter in the main scanning cross section of the diaphragm.
この他本発明では、前記光源手段と前記光偏向器との間
の光路中に副走査方向に屈折力を有するシリンドリカル
レンズを配置し、副走査断面内において該光源手段から
の光束か前記光偏向器の偏向反射面上に集光するように
し、又前記結像レンズをアナモフィック系より構成し、
副走査断面内において該偏向反射面と前記被走査面とが
略共役開係となるようにし、又主走査断面における該被
走査面上の光走査か該光偏向器の回転角に対して線形と
なるように各要素を設定したことを特徴としている。In addition, in the present invention, a cylindrical lens having refractive power in the sub-scanning direction is disposed in the optical path between the light source means and the optical deflector, and in the sub-scanning cross section, the light beam from the light source means or the light deflector is The light is focused on a deflection reflecting surface of the device, and the imaging lens is configured from an anamorphic system,
In the sub-scanning cross section, the deflection reflecting surface and the scanned surface are arranged to have a substantially conjugate relationship, and in the main scanning cross-section, the optical scanning on the scanned surface is linear with respect to the rotation angle of the optical deflector. The feature is that each element is set so that.
（天施例）
第１図は本発明の第１実施例の要部斜視図、第２図は第
１図の主要部分を主走査面内に展開したときの光束の走
査状、態を示す説明図である。(Top Example) Fig. 1 is a perspective view of the main part of the first embodiment of the present invention, and Fig. 2 shows the scanning state of the light beam when the main part of Fig. 1 is expanded in the main scanning plane. It is an explanatory diagram.
第１．第２図において１は半導体レーザー等の光源手段
であり、発散光束を放射している。光源手段１からの発
散光束は前述の条件式（１）を満足するように構成され
た所定の開口部を有する較り２によって、その断面の大
きさが整形されて光偏向器３の偏向反射面３ａに入射す
る。1st. In FIG. 2, reference numeral 1 denotes a light source means such as a semiconductor laser, which emits a diverging light beam. The diverging light beam from the light source means 1 is shaped in cross-sectional size by the aperture 2 having a predetermined opening configured to satisfy the above-mentioned conditional expression (1), and is deflected and reflected by the optical deflector 3. The light is incident on surface 3a.
光偏向器３は回転多面鏡より成り、駆動手段４により矢
印５の方向に等速で高速回転している。The optical deflector 3 is composed of a rotating polygon mirror, and is rotated at a constant speed in the direction of an arrow 5 by a driving means 4 at high speed.
光偏向器３の偏向反射面３ａ（第２図では位置Ｐで示し
ている。）に入射した光束は反射されて主走査断面にお
いて偏向走査され、ｆ−θ特性を有する結像レンズ６に
入射する。結像レンズ６は主走査断面と副走査断面にお
いて同じ屈折力を有したレンズ系より成っている。The light beam incident on the deflection reflection surface 3a (indicated by position P in FIG. 2) of the optical deflector 3 is reflected, deflected and scanned in the main scanning cross section, and is incident on the imaging lens 6 having f-θ characteristics. do. The imaging lens 6 is composed of a lens system having the same refractive power in the main scanning section and the sub-scanning section.
結像レンズ６を通過した光束は被走査面である感光トラ
ム７面上に導光されて光偏向器３の回転によりその面上
を矢印８方向に等速直線運動で光走査している。The light beam that has passed through the imaging lens 6 is guided onto the surface of the photosensitive tram 7, which is the surface to be scanned, and is optically scanned on that surface by the rotation of the optical deflector 3 in a uniform linear motion in the direction of the arrow 8.
本実施例では光源手段１から光偏向器３の偏向反射面３
ａに入射する光束は発散光束であり、絞り２はこの発散
光束を制限している。各要素の具体的な数値例を示すと
光源手段１の光射出面１ａから光偏向器３の偏向反射面
３ａ（第２図では位置Ｐ）までの距離は５０ ｍ ｍ、
偏向反射面３ａより結像レンズ６まての距離は３０ｍｍ
、結像レンズ６より感光ドラム７面までの距離は１７０
ｍｍ、結像レンズ６の焦点塵１１ｆは５４．５ｍｍ、絞
り２は光源手段１の光射出面１ａから距９２０ ｍ ｍ
の位置に配置され、主走査断面内の開口径りは１．０６
ｍｍである。In this embodiment, from the light source means 1 to the deflection reflecting surface 3 of the optical deflector 3
The light beam incident on a is a diverging light beam, and the aperture 2 limits this diverging light beam. To give a specific numerical example of each element, the distance from the light exit surface 1a of the light source means 1 to the deflection reflection surface 3a of the optical deflector 3 (position P in FIG. 2) is 50 mm;
The distance from the deflection reflection surface 3a to the imaging lens 6 is 30 mm.
, the distance from the imaging lens 6 to the surface of the photosensitive drum 7 is 170
mm, the focal point dust 11f of the imaging lens 6 is 54.5 mm, and the distance of the aperture 2 from the light exit surface 1a of the light source means 1 is 920 mm.
The aperture diameter in the main scanning section is 1.06.
It is mm.
このような構成において光源手段１のカップリング効率
は約２％、結像倍率は約２倍である。In such a configuration, the coupling efficiency of the light source means 1 is about 2%, and the imaging magnification is about 2 times.
通常、感光トラム７面上での焦点深度は±４ｍｍ程度で
ある。従って結像倍率をβ、光源手段１の光射出面１ａ
の設定基準位置からの位置すれ量をΔとすると
Δ×β２≦４
である。光源手段１の光射出面１ａと較り２との距離を
２、絞り２の主走査断面内の開口径をＤ、光射出面１ａ
からの光束の主波長（ピーク波長）をえとしたとき前述
の如く
となるように各要素を構成している。Usually, the depth of focus on the surface of the photosensitive tram 7 is about ±4 mm. Therefore, the imaging magnification is β, and the light exit surface 1a of the light source means 1
Letting Δ be the amount of positional deviation from the set reference position, Δ×β2≦4. The distance between the light emission surface 1a of the light source means 1 and the comparison 2 is 2, the aperture diameter in the main scanning section of the aperture 2 is D, and the light emission surface 1a
Each element is constructed so that the main wavelength (peak wavelength) of the light beam from the light beam is as described above.
本実施例ではこのように各要素を設定することにより、
例えば光源手段１の位置か光軸方向に０．５６ｍｍズし
ても感光トラム７面上でのどント位置のズレかＱ、２５
ｍｍ程度となり、この値か十分焦点深度内に入るように
している。これにより本実施例では各要素のピント調整
を不要とし、各要素の組立を容易にしている。In this example, by setting each element in this way,
For example, even if the position of the light source means 1 shifts by 0.56 mm in the optical axis direction, will the position of the light source on the surface of the photosensitive tram 7 shift?Q, 25
This value is about mm, and this value is well within the depth of focus. This eliminates the need for focus adjustment of each element in this embodiment, making assembly of each element easy.
第３図は本発明の第２実施例の要部斜視図である。本実
施例は走査系として光偏向器３の各偏向反射面の基準面
からの倒れを補正した所謂倒れ補正系を構成している。FIG. 3 is a perspective view of essential parts of a second embodiment of the present invention. In this embodiment, a so-called inclination correction system is configured as a scanning system, which corrects inclination of each deflection reflection surface of the optical deflector 3 from a reference plane.
本実施例では光源手段１から出射された発散光束はシリ
ンドリカルレンズ１２により集光された後、前述の条件
を満足するように設定された絞り２によってその光束断
面の大きさか整えられて光偏向器３の偏向反射面３ａに
入射する。シリンドリカルレンズ１２は副走査断面に関
しては屈折力を持ち主走査断面に関しては屈折力を持っ
ていない。この為シリンドリカルレンズ１２を通過した
光束は主走査断面では発散光束で、副走査断面ではほぼ
線状に結像されて偏向反射面３ａに入射する。In this embodiment, the diverging light beam emitted from the light source means 1 is condensed by the cylindrical lens 12, and then the size of the cross section of the light beam is adjusted by the aperture 2, which is set to satisfy the above-mentioned conditions. The light is incident on the deflection reflection surface 3a of No.3. The cylindrical lens 12 has refractive power in the sub-scanning section, but has no refractive power in the main-scanning section. For this reason, the light beam passing through the cylindrical lens 12 is a diverging light beam in the main scanning section, and is formed into a substantially linear image in the sub-scanning section, and is incident on the deflection/reflection surface 3a.
光偏向器３は矢印５の方向に回転軸５ａを中心に等速で
高速回転しており、偏向反射面３ａに入射した該光束は
反射されて主走査断面において偏向走査され、結像レン
ズ１３に入射する。The optical deflector 3 rotates at a constant speed in the direction of an arrow 5 about a rotation axis 5a, and the light beam incident on the deflection reflection surface 3a is reflected and deflected and scanned in the main scanning cross section, and then the imaging lens 13 incident on .
結像レンズ１３は主走査断面と副走査断面において異な
った屈折力を有したトーリック面を有するアナモフィッ
ク系より成っている。結像レンズ１３を通過した光束は
被走査面である感光ドラム７面上に結像されてその面上
を略等速度直線運動で光走査する。The imaging lens 13 is made of an anamorphic lens having a toric surface having different refractive powers in the main scanning section and the sub-scanning section. The light beam that has passed through the imaging lens 13 forms an image on the surface of the photosensitive drum 7, which is the surface to be scanned, and optically scans the surface with a substantially uniform linear motion.
結像レンズ１３は副走査断面内において偏向反射面３ａ
と感光ドラム７面とが略共役関係となるようにしている
。これにより本実施例では、例えば偏向反射面が副走査
断面において回転軸５ａに対して平行でなく倒れても（
即ち面倒れがあ）ても）光束は感光トラム７上の同一走
査線上に結像される。このようにして所謂光偏向器３の
偏向反射面の面倒れ補正系を構成している。The imaging lens 13 has a deflection reflecting surface 3a in the sub-scanning section.
and the surface of the photosensitive drum 7 are arranged to have a substantially conjugate relationship. As a result, in this embodiment, even if the deflection reflection surface is not parallel to the rotation axis 5a in the sub-scanning section and is tilted (
That is, even if the surface is tilted, the light beams are imaged on the same scanning line on the photosensitive tram 7. In this way, a so-called surface inclination correction system for the deflection/reflection surface of the optical deflector 3 is constructed.
尚、本実施例においてシリントリカルレンズ１２と較り
２とを一体構成しても良い。又シリンドリカルレンズ１
２を絞り２と光偏向器３との間の光路中に配置し・でも
良い。In this embodiment, the cylindrical lens 12 and the cylindrical lens 2 may be integrated. Also cylindrical lens 1
2 may be placed in the optical path between the aperture 2 and the optical deflector 3.
（発明の効果）
本発明によれば光源手段と光偏向器との間の光路中に前
述の条件を満足する開口径を有する絞りを配置すること
により、コリメーターレンズを用いずに、かつ各要素の
組立上の複雑な調整を必要とせす容易に各要素を組立て
ることができ、かつ被走査面上を高精度に光走査するこ
とができる走査光学装置を達成することができる。(Effects of the Invention) According to the present invention, by arranging a diaphragm having an aperture diameter that satisfies the above conditions in the optical path between the light source means and the optical deflector, each It is possible to achieve a scanning optical device in which the elements can be easily assembled without requiring complicated adjustments in assembling the elements, and which can scan the surface to be scanned with light with high precision.
第１図は本発明の第１実施例の要部斜視図、第２図は第
１図の主要部分を展開したときの光束の走査状態を示す
説明図、第３図は本発明の第２実施例の要部斜視図、第
４図は従来の走査光学装置の要部斜視図である。
図中、１は光源手段、２は絞り、３は光偏向器、３ａは
偏向反射面、４は駆動手段、６，１３は結像レンズ、７
は感光トラム、１２はシリンドリカルレンズである。
特許出願人 キャノン株式会社
一−階−−□□□吻１
代 理 人 高 梨 幸 雄□□□
１□Ｉ
第１図
第３図
第４図FIG. 1 is a perspective view of the main part of the first embodiment of the present invention, FIG. 2 is an explanatory diagram showing the scanning state of the light beam when the main part of FIG. FIG. 4 is a perspective view of a main part of a conventional scanning optical device. In the figure, 1 is a light source means, 2 is an aperture, 3 is a light deflector, 3a is a deflection reflection surface, 4 is a driving means, 6 and 13 are imaging lenses, and 7
is a photosensitive tram, and 12 is a cylindrical lens. Patent Applicant: Canon Co., Ltd. 1st Floor - □□□1 Deputy Director Yukio Takanashi□□□
1□I Figure 1 Figure 3 Figure 4
Claims (2)
向させた後、結像レンズを介して被走査面上に導光し、
該光偏向器を回動させることにより、該被走査面上を主
走査方向に光走査する際、該光源手段から放射される光
束の主波長をλ、該光源手段の光射出面から該絞りまで
の距離をｌ、該絞りの主走査断面内における開口径をＤ
としたとき （４／π）・（ｌ＾２／Ｄ＾２）・λ≧０．５なる条件
を満足するように各要素を設定したことを特徴とする走
査光学装置。(1) After the light beam from the light source means is deflected by an optical deflector via an aperture, the light is guided onto the scanned surface via an imaging lens,
By rotating the optical deflector, when optically scanning the surface to be scanned in the main scanning direction, the main wavelength of the light beam emitted from the light source means is set to λ, and the aperture is changed from the light exit surface of the light source means to the aperture. The distance to
A scanning optical device characterized in that each element is set so as to satisfy the following condition: (4/π)・(l^2/D^2)・λ≧0.5.
走査方向に屈折力を有するシリンドリカルレンズを配置
し、副走査断面内において該光源手段からの光束が前記
光偏向器の偏向反射面上に集光するようにし、又前記結
像レンズをアナモフィック系より構成し、副走査断面内
において該偏向反射面と前記被走査面とが略共役関係と
なるようにし、又主走査断面における該被走査面上の光
走査が該光偏向器の回転角に対して線形となるように各
要素を設定したことを特徴とする請求項１記載の走査光
学装置。(2) A cylindrical lens having refractive power in the sub-scanning direction is disposed in the optical path between the light source means and the optical deflector, and the light beam from the light source means is deflected by the optical deflector in the sub-scanning cross section. The light is focused on a reflective surface, and the imaging lens is constructed of an anamorphic system, so that the deflection reflective surface and the scanned surface have a substantially conjugate relationship within the sub-scanning cross-section, and the main-scanning cross-section 2. The scanning optical device according to claim 1, wherein each element is set so that the optical scanning on the scanned surface is linear with respect to the rotation angle of the optical deflector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31684790A JPH04186214A (en) | 1990-11-20 | 1990-11-20 | Scanning optical device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31684790A JPH04186214A (en) | 1990-11-20 | 1990-11-20 | Scanning optical device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04186214A true JPH04186214A (en) | 1992-07-03 |
Family
ID=18081583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31684790A Pending JPH04186214A (en) | 1990-11-20 | 1990-11-20 | Scanning optical device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04186214A (en) |
-
1990
- 1990-11-20 JP JP31684790A patent/JPH04186214A/en active Pending
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