JPH11352426A - Multi-beam scanning device - Google Patents
Multi-beam scanning deviceInfo
- Publication number
- JPH11352426A JPH11352426A JP10156119A JP15611998A JPH11352426A JP H11352426 A JPH11352426 A JP H11352426A JP 10156119 A JP10156119 A JP 10156119A JP 15611998 A JP15611998 A JP 15611998A JP H11352426 A JPH11352426 A JP H11352426A
- Authority
- JP
- Japan
- Prior art keywords
- optical system
- beams
- scanning
- deflecting
- optical
- 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.)
- Granted
Links
Landscapes
- Facsimile Scanning Arrangements (AREA)
- Laser Beam Printer (AREA)
- Mechanical Optical Scanning Systems (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明はマルチビーム走査
装置に関する。この発明は、デジタル複写装置、ファク
シミリやレーザプリンタにおける光走査装置に利用でき
る。The present invention relates to a multi-beam scanning device. INDUSTRIAL APPLICABILITY The present invention is applicable to a digital copying machine, an optical scanning device in a facsimile or a laser printer.
【０００２】[0002]
【従来の技術】デジタル複写装置等に関連して広く知ら
れた光走査装置は一般に、光源を第１光学系でカップリ
ングし、第１光学系からのビームを主走査方向（光源か
ら被走査面における光路の屈曲を無視して、被走査面上
における主走査方向と対応する方向を言う、副走査方向
についても同様である）に長く略線状に集光し、この線
状の集光部の近傍に偏向反射面を有する偏向器で偏向さ
せ、偏向器による偏向ビームを第３光学系により被走査
面上に集光させて被走査面の走査を行うようになってい
る。近来、光走査の高速化を目して、被走査面を複数ビ
ームで同時に走査するマルチビーム走査装置の実用化が
意図されている。マルチビーム走査装置では複数の光源
が用いられるが、これら複数の光源からの複数ビームを
被走査面上で近接して集光させるために、偏光を利用し
たビーム合成部品を用いて複数ビームを合成することが
提案されている（例えば、特開平８−３０４７２２号公
報）。これに対し、偏光を利用した高価なビーム合成部
品を用いることなくマルチビーム走査を可能にしたもの
として、複数のビームに偏向回転面内（偏向反射面の回
転軸に直交する平面）で「開き角（上記複数ビームを偏
向回転面に射影したときの各ビームの射影のなす角）」
を持たせる方式のマルチビーム走査装置が提案された
（特開平９−１４６０２４号公報）。しかし、この場
合、「偏向反射面とその回転軸が一定距離離れている偏
向器」を用いると、開き角を有する複数のビームで「サ
グ量（各ビームの線状の集光部と偏向反射面とが、偏向
反射面の回転に伴いずれる、ずれ量）」が異なるので、
全てのビームについて良好な光学特性（ビームスポット
径、等速性等）を得るには、ビームごとにサグ量が異な
るという事実に立脚した光学設計が必要になる。2. Description of the Related Art Generally, an optical scanning device widely known in relation to a digital copying machine or the like generally includes a light source coupled to a first optical system, and a beam from the first optical system is scanned in a main scanning direction (from a light source to a scanned object). Irrespective of the bending of the optical path on the surface, the direction corresponding to the main scanning direction on the surface to be scanned, which is also the same in the sub-scanning direction). The light is deflected by a deflector having a deflecting / reflecting surface in the vicinity of the section, and the beam deflected by the deflector is condensed on the surface to be scanned by a third optical system to scan the surface to be scanned. 2. Description of the Related Art Recently, a multi-beam scanning apparatus that simultaneously scans a surface to be scanned with a plurality of beams has been intended to increase the speed of optical scanning. Multiple light sources are used in a multi-beam scanning device.To converge multiple beams from these multiple light sources close to the surface to be scanned, the multiple beams are combined using a beam combining component using polarization. (For example, Japanese Patent Laid-Open No. 8-304722). On the other hand, as a multi-beam scanning method without using expensive beam combining parts using polarization, a plurality of beams are "opened" in a deflecting rotation plane (a plane orthogonal to the rotation axis of the deflecting reflection plane). Angle (the angle formed by the projection of each beam when the multiple beams are projected onto the deflecting rotation surface) "
There has been proposed a multi-beam scanning apparatus of a type having the following (Japanese Patent Laid-Open Publication No. 9-146024). However, in this case, when a “deflecting device in which the deflecting / reflecting surface and its rotation axis are separated by a certain distance” is used, the “sag amount (a linear condensing portion of each beam and the deflecting / reflecting Surface is shifted with the rotation of the deflecting / reflecting surface),
To obtain good optical characteristics (beam spot diameter, constant velocity, etc.) for all beams, an optical design based on the fact that the sag amount differs for each beam is required.
【０００３】[0003]
【発明が解決しようとする課題】この発明は、偏光を利
用した高価なビーム合成部品を用いずに複数ビームで被
走査面を走査でき、なおかつ、全てのビームについて、
ビームスポット径、等速性等の光学特性を良好にでき
る、高速化・高画質化に対応可能なマルチビーム走査装
置の実現を課題とする。SUMMARY OF THE INVENTION According to the present invention, a surface to be scanned can be scanned with a plurality of beams without using an expensive beam combining component utilizing polarized light.
It is an object of the present invention to realize a multi-beam scanning apparatus capable of improving optical characteristics such as a beam spot diameter and uniform velocity and capable of responding to high speed and high image quality.
【０００４】[0004]
【課題を解決するための手段】この発明のマルチビーム
走査装置は、複数の光源と、複数の第１光学系と、第２
光学系と、偏向器と、第３光学系とを有する。According to the present invention, there is provided a multi-beam scanning apparatus comprising: a plurality of light sources; a plurality of first optical systems;
It has an optical system, a deflector, and a third optical system.
【０００５】「複数の光源」は、光走査用のビームをそ
れぞれ独立して放射する。これら光源としては半導体レ
ーザ（ＬＤ）が好適である。「第１光学系」は、これら
複数の光源をそれぞれカップリングする。第１光学系は
各光源に応じて設けられる。カップリングされたビーム
は「平行ビーム」となってもよいし「弱い収束ビームも
しくは弱い発散ビーム」となってもよい。「第２光学
系」は、各第一光学系からのビームを主走査方向に長く
略線状に集光させる光学系であり、シリンダレンズや凹
シリンダミラーを好適に利用することができる。この第
２光学系は、各光源からのビームごとに、即ち、光源と
同数設けても良いが、複数光源に共通して配備してもよ
い。「偏向器」は、略線状の集光部の近傍に偏向反射面
を有し、第２光学系からの複数ビームを等角速度的に偏
向するが、偏向反射面とその回転軸が一定距離離れてい
る。即ち、偏向器は、複数の光源からの各ビームに共通
して用いられ、複数の光源からのビームは、共通の偏向
反射面により偏向される。かかる偏向器としては、回転
多面鏡や回転２面鏡を好適に用いることができるが、偏
向反射面とその回転軸の離れた「回転単面鏡」を用いる
こともできる。「第３光学系」は、偏向器により偏向さ
れた複数の偏向ビームを被走査面に向けて集光させ、被
走査面を略等速的に走査する走査結像素子を含む。第３
光学系は、偏向ビームの光路を屈曲させる折り返しミラ
ー等の光学素子を含むことができる。「走査結像光学
系」は１以上のレンズ、あるいは１以上の結像ミラーに
より構成することができ、更には１以上のレンズと１以
上の結像ミラーの複合系として構成することもできる。
上記第２光学系からの複数のビームは、走査結像素子の
外側の同じ側から偏向反射面に向かい、第２光学系から
の複数のビームのうち少なくとも２つは偏向回転面内で
開き角を有する。「開き角」は、上記２つのビームを
「偏向回転面内に射影した状態」において「各ビームが
偏向反射面の側から第２光学系の側へ向かって開くよう
になす角」を言う。The “plurality of light sources” independently emit light beams for optical scanning. Semiconductor lasers (LD) are suitable as these light sources. The “first optical system” couples the plurality of light sources. The first optical system is provided according to each light source. The coupled beam may be a “parallel beam” or a “weak convergent beam or a weak divergent beam”. The “second optical system” is an optical system that condenses the beam from each of the first optical systems in a substantially linear shape in the main scanning direction, and can suitably use a cylinder lens or a concave cylinder mirror. The second optical system may be provided for each beam from each light source, that is, as many as the number of light sources, or may be provided commonly for a plurality of light sources. The “deflector” has a deflecting / reflecting surface near a substantially linear condensing portion, and deflects a plurality of beams from the second optical system at an equal angular velocity. is seperated. That is, the deflector is used in common for each beam from a plurality of light sources, and the beams from the plurality of light sources are deflected by a common deflecting and reflecting surface. As such a deflector, a rotating polygon mirror or a rotating dihedral mirror can be suitably used, but a "rotating single mirror" having a deflecting reflection surface and a rotation axis separated from each other can also be used. The “third optical system” includes a scanning imaging element that converges a plurality of deflection beams deflected by the deflector toward the surface to be scanned and scans the surface to be scanned at a substantially constant speed. Third
The optical system can include an optical element such as a folding mirror that bends the optical path of the deflected beam. The “scanning optical system” can be configured by one or more lenses or one or more imaging mirrors, and can also be configured as a composite system of one or more lenses and one or more imaging mirrors.
The plurality of beams from the second optical system are directed to the deflecting / reflecting surface from the same side outside the scanning imaging element, and at least two of the plurality of beams from the second optical system are opened at an angle of divergence in the deflecting rotation surface. Having. The “opening angle” refers to “an angle at which each beam is opened from the side of the deflecting / reflecting surface to the side of the second optical system” in a state where the two beams are projected onto the deflecting rotation plane.
【０００６】請求項１記載のマルチビーム走査装置は、
上記の如き構成において「偏向器による複数の偏向ビー
ムの主光線が被走査面上の走査ラインと直交するときの
該各主光線を基準線とするとき、第３光学系の少なくと
も１つの走査光学素子の光軸が上記全ての基準線からみ
て、偏向反射面に向かうビーム側にシフトして配備され
る」ことを特徴とする。「基準線」は、偏向器により偏
向された任意のビームの主光線をそのまま、走査結像光
学系により屈折させることなく被走査面に導いたとすれ
ば、被走査面上で走査ライン（当該ビームにより走査さ
れる線）に直交するであろう状態における主光線を、装
置空間に固定したものであって、一般には各ビームごと
に異なり、偏向回転面内への射影は互いに平行である。
この請求項１記載のマルチビーム走査装置において、第
３光学系の、少なくとも１つの走査光学素子を基準線に
対して、チルト（偏向回転面内で基準線に対して傾ける
ことを言う）して配備されることができる（請求項
２）。即ち、走査結像光学系はシフトとチルトを受ける
ことができる。シフト・チルトはいずれも、走査結像光
学系のサグによる性能劣化を回復させる有効な手段であ
る。請求項３記載のマルチビーム走査装置は、以下の如
き特徴を有する。即ち、上記複数の光源によるビームの
うちの１つのビームの、両最周辺像高での副走査方向結
像位置（両最周辺像高での副走査方向の像面湾曲量を言
う、以下同様）を、S1(+)，S1(-)、上記以外の１つの光
源によるビームの両最周辺像高での副走査方向結像位置
をS2(+)，S2(-)とするとき、これらが条件： （１） (S1(+)-S1(-))×(S2(+)-S2(-))＜0 を満足する。請求項４記載のマルチビーム走査装置は、
以下の如き特徴を有する。即ち、上記複数の光源による
ビームのうちの１つのビームの両最周辺像高での主走査
方向結像位置（両最周辺像高における主走査方向の像面
湾曲量をいう。以下同様）を、M1(+)，M1(-)、上記以外
の１つの光源によるビームの両最周辺像高での主走査方
向結像位置をM2(+)，M2(-)とするとき、これらが条件： （２） (M1(+)-M1(-))×(M2(+)-M2(-))＜0 を満足する。請求項５記載のマルチビーム走査装置は、
以下の如き特徴を有する。即ち、上記複数の光源による
ビームのうちの１つのビームの両最周辺像高での主走査
方向結像位置をM1(+)，M1(-)、副走査方向結像位置をS1
(+)，S1(-)、上記以外の１つの光源によるビームの両最
周辺像高での主走査方向結像位置をM2(+)，M2(-)、副走
査方向結像位置をS2(+),S2(-)とするとき、これらが条
件： （１） (S1(+)-S1(-))×(S2(+)-S2(-))＜0 （２） (M1(+)-M1(-))×(M2(+)-M2(-))＜0 を共に満足する。請求項６記載のマルチビーム走査装置
は、上記請求項１ないし５の任意の１に記載のマルチビ
ーム走査装置において、偏向回転面内に射影した場合、
少なくとも２つのビームが偏向面以後で交差することを
特徴とする。なお、シフトやチルトを行わない場合で
も、走査結像素子の屈折面や反射面を主走査方向および
／または副走査方向において、光軸に関して非対称な形
状とすることにより、上記の条件（１）および／または
（２）を満足させるようにすることができる。[0006] The multi-beam scanning device according to the first aspect,
In the above configuration, when at least one principal ray of a plurality of deflection beams by the deflector is a reference line when the principal ray is orthogonal to a scanning line on the surface to be scanned, at least one scanning optical element of the third optical system is used. The optical axis of the element is shifted to the beam side toward the deflecting reflection surface when viewed from all the reference lines, and is arranged. " The “reference line” is defined as a scanning line on the surface to be scanned if the principal ray of an arbitrary beam deflected by the deflector is directly guided to the surface to be scanned without being refracted by the scanning imaging optical system. The principal ray in a state that will be orthogonal to the scanning line is fixed in the apparatus space, and generally differs for each beam, and the projections into the deflection rotation plane are parallel to each other.
2. The multi-beam scanning apparatus according to claim 1, wherein at least one scanning optical element of the third optical system is tilted with respect to the reference line (this means that the scanning optical element is tilted with respect to the reference line in the plane of rotation of deflection). It can be deployed (claim 2). That is, the scanning image forming optical system can receive shift and tilt. Both shift and tilt are effective means for recovering performance degradation due to sag of the scanning image forming optical system. The multi-beam scanning device according to the third aspect has the following features. That is, the image forming position of one of the beams from the plurality of light sources in the sub-scanning direction at both extreme image heights (refers to the field curvature in the sub-scanning direction at both extreme image heights; ) Is S1 (+), S1 (-), and the image forming positions in the sub-scanning direction at the two outermost image heights of the beam by one light source other than the above are S2 (+) and S2 (-). Satisfies the following condition: (1) (S1 (+)-S1 (-)) * (S2 (+)-S2 (-)) <0. The multi-beam scanning device according to claim 4,
It has the following features. That is, the image forming position in the main scanning direction at both extreme image heights of one of the beams from the plurality of light sources (the amount of curvature of field in the main scanning direction at both extreme image heights; the same applies hereinafter). , M1 (+), M1 (-), and M2 (+), M2 (-) when the imaging positions in the main scanning direction at the two outermost image heights of the beam from one light source other than the above are defined as conditions : (2) Satisfies (M1 (+)-M1 (-)) × (M2 (+)-M2 (-)) <0. The multi-beam scanning device according to claim 5,
It has the following features. That is, M1 (+) and M1 (-) are the image forming positions in the main scanning direction at the two outermost image heights of one of the beams from the plurality of light sources, and S1 is the image forming position in the sub-scanning direction.
(+), S1 (-), M2 (+), M2 (-) in the main scanning direction at both extreme image heights of the beam from one light source other than the above, and S2 in the sub-scanning direction. When (+) and S2 (-) are used, these conditions are: (1) (S1 (+)-S1 (-)) × (S2 (+)-S2 (-)) <0 (2) (M1 ( +) − M1 (−)) × (M2 (+) − M2 (−)) <0. According to a sixth aspect of the present invention, in the multi-beam scanning apparatus according to any one of the first to fifth aspects, when the light beam is projected on a deflection rotation plane,
At least two beams intersect after the deflection surface. Note that, even when no shift or tilt is performed, the refraction surface or the reflection surface of the scanning image forming element is asymmetric with respect to the optical axis in the main scanning direction and / or the sub-scanning direction. And / or (2) may be satisfied.
【０００７】[0007]
【発明の実施の形態】図１に示す実施の形態において、
「複数の光源」であるＬＤ１、ＬＤ２から出射された各
ビームは、それぞれ「第１光学系」をなすカップリング
レンズ３，４によりカップリングされ、「第２光学系」
をなすシリンダレンズ５，６により、それぞれが偏向反
射面７の近傍で主走査方向に長い略線状に結像する。２
ビームとも、同一の偏向器の共通の偏向反射面７により
反射されて等角速度的に偏向され、「第３光学系の走査
結像光学系」をなす走査レンズ１１、１２により被走査
面２０近傍にビームを結像させ、被走査面２０上に形成
されるビームスポットにより被走査面２０を略等速に走
査する。各ビームスポットは被走査面上において副走査
方向に所定の間隔をなす。従って、該間隔で離れた２本
の走査ラインが同時に走査される。このとき、第２光学
系であるシリンダ５，６を出射した２ビームは偏向回転
面（図１の図面に平行な面）内で開き角：γを有し、偏
向器の偏向反射面７とその回転軸７Ａは一定距離離れて
いる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIG.
The beams emitted from LD1 and LD2, which are “plural light sources”, are respectively coupled by coupling lenses 3 and 4 forming “first optical system”, and “second optical system”
Are formed in a substantially linear shape in the main scanning direction in the vicinity of the deflecting / reflecting surface 7, respectively. 2
Both beams are reflected by a common deflecting / reflecting surface 7 of the same deflector and deflected at a uniform angular velocity, and are located near a surface to be scanned 20 by scanning lenses 11 and 12 forming a “scanning image forming optical system of a third optical system”. A beam is formed on the surface to be scanned, and the surface to be scanned 20 is scanned at a substantially constant speed by a beam spot formed on the surface to be scanned 20. Each beam spot forms a predetermined interval in the sub-scanning direction on the surface to be scanned. Therefore, two scanning lines separated by the interval are simultaneously scanned. At this time, the two beams emitted from the cylinders 5 and 6, which are the second optical system, have an opening angle: γ in the deflecting rotation plane (plane parallel to the drawing of FIG. 1), and The rotating shaft 7A is separated by a certain distance.
【０００８】[0008]
【実施例】上記実施の形態に関する具体的な実施例を説
明する。EXAMPLES Specific examples of the above embodiment will be described.
【０００９】実施例１ 図１に示す構成において、ＬＤ１、ＬＤ２から出射する
ビームをそれぞれビーム１、ビーム２とする。ビーム１
と基準線Ｌ１（ビーム１の主光線が被走査面２０上の走
査ラインと直交するときの線）のなす角は６０度、ビー
ム２と基準線Ｌ２（ビーム１の主光線が被走査面２０上
の走査ラインと直交するときの線）のなす角は６４．３
度に設定されている。従って、ビーム１，２の開き角：
γは４．３度である。ビーム１、２ともカップリングレ
ンズ３，４により「平行ビーム」とされている。偏向器
は偏向反射面を６面有する「回転多面鏡」であり、回転
軸７Ａから偏向反射面７までの距離は１８ｍｍである。
ビーム１が偏向反射面７により反射されて、その主光線
が基準線Ｌ１に合致するときの「ビーム１の偏向反射面
７への入射角」は３０度、ビーム２が偏向反射面７によ
り反射されて、その主光線が基準線Ｌ２に合致するとき
の「ビーム２の偏向反射面７への入射角」は３２．１５
度であり、勿論、基準線Ｌ１，Ｌ２は、偏向回転面（図
１に示された面）への射影が互いに平行である。Embodiment 1 In the configuration shown in FIG. 1, beams emitted from LD1 and LD2 are referred to as beam 1 and beam 2, respectively. Beam 1
And the reference line L1 (the line when the principal ray of the beam 1 is orthogonal to the scanning line on the scanned surface 20) forms an angle of 60 degrees, and the beam 2 and the reference line L2 (the principal ray of the beam 1 The angle formed by a line perpendicular to the upper scanning line is 64.3.
Set to degree. Therefore, the opening angle of the beams 1 and 2:
γ is 4.3 degrees. Both beams 1 and 2 are made “parallel beams” by the coupling lenses 3 and 4. The deflector is a "rotating polygon mirror" having six deflecting reflection surfaces, and the distance from the rotation axis 7A to the deflecting reflection surface 7 is 18 mm.
When the beam 1 is reflected by the deflecting / reflecting surface 7 and its chief ray coincides with the reference line L1, the "angle of incidence of the beam 1 on the deflecting / reflecting surface 7" is 30 degrees, and the beam 2 is reflected by the deflecting / reflective surface 7. When the principal ray coincides with the reference line L2, the "incident angle of the beam 2 on the deflecting / reflecting surface 7" is 32.15.
The projection of the reference lines L1 and L2 onto the deflection rotation surface (the surface shown in FIG. 1) is, of course, parallel to each other.
【００１０】第２光学系のシリンダレンズ５，６は同じ
もので、下記のデータを有する。第１面（入射側面）副
走査方向の曲率半径：Ｒ(シリンダ面):４８ｍｍ 第２面：平面 中心肉厚：３ｍｍ 使用波長での屈折率＝１．５１１１８
。The cylinder lenses 5 and 6 of the second optical system are the same and have the following data. First surface (incident side surface) Radius of curvature in the sub-scanning direction: R (cylinder surface): 48 mm Second surface: flat Center thickness: 3 mm Refractive index at used wavelength = 1.51118
.
【００１１】第３光学系の走査レンズ１１は両面とも
「共軸非球面」であり、光軸方向の座標をＸ、頂点から
の距離をr、近軸曲率半径をRN、円錐定数をKN、高次の
係数をRNA4、RNA6、RNA8、RNA10、…(Ｎは、入射側面に
就きＮ＝１、射出側面に就きＮ＝２)として、 X=r2/[RN+RN・√｛1-(1+KN)r2/RN2}]+RNA4・r4+RNA6・r
6+RNA8・r8+RNA10・r10 で表すことができる。走査レンズ１１の材質の使用波長
での屈折率をＮ、中心肉厚をＤとすると、上記非球面形
状および屈折率・中心肉厚のデータは以下の通りであ
る。 Ｒ１ −２６４．０ Ｋ１ ２．４４９ Ｒ１Ａ４ ２．５９４Ｅ−０７ Ｒ１Ａ６ １．２５６Ｅ−１１ Ｒ１Ａ８ −２．４１６Ｅ−１３ Ｒ１Ａ１０ ４．９１０Ｅ−１７ Ｄ ２３．３ Ｎ １．５２４４１ Ｒ２ −６１．３ Ｋ２ −０．０２１３ Ｒ２Ａ４ ５．９４９Ｅ−０７ Ｒ２Ａ６ １．１２０Ｅ−１２ Ｒ２Ａ８ ２．４５２Ｅ−１４ Ｒ２Ａ１０ −３．９６９Ｅ−１７ 上の表記において、例えば「Ｅ−１７」は、１０~17を
意味し、この数値が、直前の数値にかかるのである。以
下、同様である。The scanning lens 11 of the third optical system has a "coaxial aspherical surface" on both surfaces. The coordinate in the optical axis direction is X, the distance from the vertex is r, the paraxial radius of curvature is RN, the conic constant is KN, Assuming that the higher-order coefficients are RNA4, RNA6, RNA8, RNA10,... (N is N = 1 for the incident side and N = 2 for the exit side), X = r 2 / [RN + RN · √ ｛1- (1 + KN) r 2 / RN 2}] + RNA4 · r 4 + RNA6 · r
It can be expressed by 6 + RNA8 · r 8 + RNA10 · r 10. Assuming that the refractive index of the material of the scanning lens 11 at the used wavelength is N and the center thickness is D, the data of the aspherical shape and the refractive index and the center thickness are as follows. R1-264.0 K1 2.449 R1A4 2.594E-07 R1A6 1.256E-11 R1A8 -2.416E-13 R1A10 4.910E-17 D 23.3 N 1.52441 R2-61.3 K2-0 .0213 R2A4 5.949E-07 R2A6 1.120E-12 R2A8 2.452E-14 R2A10 -3.969E-17 In the above notation, for example, “E-17” means 10 to 17 , and this numerical value is 10 to 17. , It depends on the previous value. Hereinafter, the same applies.
【００１２】第３光学系の走査レンズ１２は、両面とも
主走査方向に「非円弧形状」である。該非円弧形状は、光
軸方向の座標をＸ、主走査方向の座標をＹ、近軸曲率半
径をRmn、円錐定数をKmn、高次の係数をan、bn、cn、d
n、…（ｎは、入射側面につきｎ＝１、射出側面につき
ｎ＝２）として以下のように表現できる。 X=Y2/[Rmn+Rmn・√｛1-(1+Kmn)Y2/Rmn2}］+an・Y4+bn・
Y6+cn・Y8+dn・Y10 走査レンズ１２の材質の使用波長での屈折率をＮ、中心
肉厚をＤとすると、上記非球面形状および屈折率・中心
肉厚のデータは以下の通りである。 Rm1 -340.0 Km1 -62.03 a1 -1.047E-08 b1 -9.302E-12 c1 -1.271E-15 d1 1.863E-19 D 3.5 N 1.52441 Rm2 -680.0 Km2 19.12 a2 -1.314E-07 b2 -2.256E-12 c2 1.004E-16 d2 -2.522E-20
。The scanning lens 12 of the third optical system has a "non-arc shape" in the main scanning direction on both surfaces. The non-circular shape is such that the coordinates in the optical axis direction are X, the coordinates in the main scanning direction are Y, the paraxial radius of curvature is Rmn, the conic constant is Kmn, and the higher-order coefficients are an, bn, cn, and d.
(n is n = 1 for the entrance side and n = 2 for the exit side) can be expressed as follows. X = Y 2 / [Rmn + Rmn · √ {1- (1 + Kmn) Y 2 / Rmn 2}] + an · Y 4 + bn ·
Y 6 + cn · Y 8 + dn · Y 10 Assuming that the refractive index of the material of the scanning lens 12 at the used wavelength is N and the center thickness is D, the data of the aspherical shape and the refractive index / center thickness are as follows. It is as follows. Rm1 -340.0 Km1 -62.03 a1 -1.047E-08 b1 -9.302E-12 c1 -1.271E-15 d1 1.863E-19 D 3.5 N 1.52441 Rm2 -680.0 Km2 19.12 a2 -1.314E-07 b2 -2.256E-12 c2 1.004E-16 d2 -2.522E-20
.
【００１３】走査レンズ１２の、副走査曲率半径（副走
査方向に平行な断面内の曲率半径）：rns(Y)（ｎは、入
射側面に就きｎ＝１、射出側面につきｎ＝２）は、主走
査方向の座標：Ｙに応じて、 rns(Y)=RnS+en・Y2+fn・Y4+gn・Y6+hn・Y8+in・Y10+jn
・Y12 (RnSはY=0での曲率半径）で表すことができ、以下のデ
ータで特定される。The sub-scanning radius of curvature (radius of curvature in a section parallel to the sub-scanning direction) of the scanning lens 12: rns (Y) (n is n = 1 for the entrance side surface and n = 2 for the exit side surface) is , Coordinates in the main scanning direction: according to Y, rns (Y) = RnS + en · Y 2 + fn · Y 4 + gn · Y 6 + hn · Y 8 + in · Y 10 + jn
· Y 12 (RNS is the radius of curvature of at Y = 0) can be represented by, it is identified by the following data.
【００１４】 R1S=-32.01 e1=1.385E-03,f1=-4.354E-07,g1=2.324E-11,h1=3.250E-15,i1=-2.023E-19, j1=-6.203E-23 R2S=-16.97 e2=f2=g2=・・・=0 。R1S = -32.01 e1 = 1.385E-03, f1 = -4.354E-07, g1 = 2.324E-11, h1 = 3.250E-15, i1 = -2.023E-19, j1 = -6.203E- 23 R2S = -16.97 e2 = f2 = g2 = ... = 0.
【００１５】基準線Ｌ１の偏向反射面での反射点と走査
レンズ１１の第１面との距離：４４．４ｍｍ、走査レン
ズ１１の第２面と走査レンズ１２第１面との距離：５
０．４ｍｍ、走査レンズ１２の第２面と被走査面との距
離：１０７．１ｍｍである。また、偏向器による反射ビ
ームの主光線が基準線（Ｌ１、Ｌ２）と一致するときの
ビーム１のシリンダレンズから偏向反射面までの距離：
９１．９２ｍｍ、ビーム２のシリンダレンズから偏向反
射面までの距離：９１．６６ｍｍである。ビーム１が基
準線Ｌ１と一致するときの、偏向反射面上での２ビーム
の距離は０．６２ｍｍであり、偏向回転面に２ビームを
射影すると偏向反射面以後においてビーム１，２が交差
する。これにより、被走査面上で２ビームが走査できる
範囲の重なり部分を大きくでき、偏向反射面が小さくて
も広い範囲の走査が可能になる（請求項６）。The distance between the reflection point of the reference line L1 on the deflection reflecting surface and the first surface of the scanning lens 11: 44.4 mm, the distance between the second surface of the scanning lens 11 and the first surface of the scanning lens 12: 5
0.4 mm, and the distance between the second surface of the scanning lens 12 and the surface to be scanned: 107.1 mm. Further, when the principal ray of the beam reflected by the deflector coincides with the reference line (L1, L2), the distance of the beam 1 from the cylinder lens to the deflecting reflection surface:
The distance from the cylinder lens of beam 2 to the deflecting / reflecting surface is 91.66 mm. When the beam 1 coincides with the reference line L1, the distance between the two beams on the deflecting / reflecting surface is 0.62 mm. When the two beams are projected on the deflecting rotating surface, the beams 1 and 2 intersect after the deflecting / reflecting surface. . As a result, it is possible to increase the overlapping portion of the range in which two beams can be scanned on the surface to be scanned, and it is possible to scan a wide range even if the deflecting reflection surface is small.
【００１６】図１に示すように、基準線Ｌ１から走査レ
ンズ１１の第１面頂点までの距離をΔ１、基準線Ｌ２か
ら走査レンズ１１の第１面頂点までの距離をΔ２、基準
線Ｌ１から走査レンズ１２の第１面頂点までの距離をΔ
１’、基準線Ｌ２から走査レンズ１２の第１面頂点まで
の距離をΔ２’(全て、偏向器への入射ビーム側，即
ち、図１の上方をプラス方向とする）とすると、Δ１＝
１．００ｍｍ，Δ２＝０．４５ｍｍ，Δ１’＝０．９０
ｍｍ，Δ２’＝０．３５ｍｍとなり、請求項１における
「シフトの条件」を満足している。チルト量：α、βは
共に０であり、走査レンズ１１、１２の光軸は互いに平
行である。As shown in FIG. 1, the distance from the reference line L1 to the vertex of the first surface of the scanning lens 11 is Δ1, the distance from the reference line L2 to the vertex of the first surface of the scanning lens 11 is Δ2, and the distance from the reference line L1 is Δ2. The distance to the first surface vertex of the scanning lens 12 is Δ
1 ′, if the distance from the reference line L2 to the vertex of the first surface of the scanning lens 12 is Δ2 ′ (all beams are incident on the deflector, that is, the upper side in FIG. 1 is a plus direction), Δ1 =
1.00 mm, Δ2 = 0.45 mm, Δ1 ′ = 0.90
mm, Δ2 ′ = 0.35 mm, which satisfies the “shift condition” in claim 1. The tilt amounts: α and β are both 0, and the optical axes of the scanning lenses 11 and 12 are parallel to each other.
【００１７】図２に示すように、偏向反射面７とその回
転軸７Ａが一致していない場合、周辺に向かうビームの
反射点は中心に向かうビームの反射点：Ｃに対して、入
射ビーム側（図の上方）にずれる。従って、第３光学系
の走査レンズの少なくとも１つは全ての基準線に対して
入射ビーム側にシフトしないと光学特性が劣化する。実
施例１の２ビームに関する主・副走査方向の像面湾曲及
び等速性（理想像高からのずれ量×１００／理想像向
（％））を図３に示す。これらは全て良好に補正されて
いる。実施例１において、S1(+)=0.01，S1(-)=0.11，S2
(+)=0.57，S2(-)=-0.37で、 (S1(+)-S1(-))×(S2(+)-S2(-))=-0.094 ＜ 0 となり、条件式(１)を満足する（請求項３）。また、M1
(+)=0.16，M1(-)=0.06，M2(+)=-0.14，M2(-)=0.11で、 (M1(+)-M1(-))×(M2(+)-M2(-))=-0.025 ＜ 0 となり、条件式(２)を満足する（請求項４)。即ち、実
施例１では、条件式(１)，(２)ともに満足され、主・副
走査方向とも良好な結像性能が得られる（請求項５）。
ビーム１，２が「開き角」を持って偏向器に入射してい
るため、ビーム１とビーム２とでサグ量が異なり、結像
性能が異なる。従って、条件式（１），（２）を満足し
ないと、一方のビームに対して良好な結像性能を持たせ
ることができても、他方のビームに対しては良好な結像
性能を持たせることができない。条件式(１)，(２)を満
足することにより、バランスのとれた設計が可能とな
る。As shown in FIG. 2, when the deflecting / reflecting surface 7 does not coincide with the rotation axis 7A, the reflection point of the beam directed to the periphery is shifted with respect to the reflection point of the beam directed to the center: C on the incident beam side. (Upper part of the figure). Therefore, unless at least one of the scanning lenses of the third optical system shifts to the incident beam side with respect to all the reference lines, the optical characteristics deteriorate. FIG. 3 shows the curvature of field in the main and sub-scanning directions and the uniformity (deviation from ideal image height × 100 / ideal image direction (%)) for the two beams of the first embodiment. These are all well corrected. In the first embodiment, S1 (+) = 0.01, S1 (-) = 0.11, S2
(+) = 0.57, S2 (-) =-0.37, (S1 (+)-S1 (-)) × (S2 (+)-S2 (-)) =-0.094 <0, and the conditional expression (1) Is satisfied (claim 3). Also, M1
(+) = 0.16, M1 (-) = 0.06, M2 (+) =-0.14, M2 (-) = 0.11, (M1 (+)-M1 (-)) × (M2 (+)-M2 (- )) =-0.025 <0, thereby satisfying the conditional expression (2) (claim 4). That is, in the first embodiment, both the conditional expressions (1) and (2) are satisfied, and good imaging performance is obtained in both the main and sub-scanning directions.
Since the beams 1 and 2 enter the deflector with an “open angle”, the sag amount differs between the beam 1 and the beam 2 and the imaging performance differs. Therefore, if conditional expressions (1) and (2) are not satisfied, good imaging performance can be provided for one beam, but good imaging performance can be provided for the other beam. I can't let it. By satisfying conditional expressions (1) and (2), a well-balanced design becomes possible.
【００１８】比較例１ 実施例１に対する比較例として、実施例１に対し下記の
変更を行う。Comparative Example 1 As a comparative example of Example 1, the following changes are made to Example 1.
【００１９】Δ１＝０．００ｍｍ，Δ２＝−０．５５ｍ
ｍ，Δ１’＝０．００ｍｍ，Δ２’＝−０．５５ｍｍ このとき、走査レンズ１１は基準線Ｌ１に対してシフト
がないため、請求項１における「第３光学系の少なくと
も１つの走査光学素子の光軸が上記全ての基準線からみ
て、偏向反射面に向かうビーム側にシフトして配備され
る」との条件を満足しない。このときのビーム１，２に
関する像面湾曲および等速性は、図４に示すごとくであ
り、ビーム１，２とも特に副走査の像面湾曲が劣化して
いる。また、S1(+)=0.92，S1(-)=-0.73，S2(+)=1.37，S
2(-)=-1.21であって、 (S1(+)-S1(-))×(S2(+)-S2(-))=4.257 ＞ 0 、 M1(+)=-0.26,M1(-)=0.21,M2(+)=-0.79,M2(-)=0.19であ
って、 (M1(+)-M1(-))×(M2(+)-M2(-))=0.461 ＞0 となり、条件式(１)，(２)のいずれも満足されない。Δ1 = 0.00 mm, Δ2 = −0.55 m
m, Δ1 ′ = 0.00 mm, Δ2 ′ = − 0.55 mm At this time, since the scanning lens 11 has no shift with respect to the reference line L1, at least one scanning optical element of the third optical system in claim 1 Are arranged shifted toward the beam toward the deflecting reflecting surface when viewed from all the reference lines. " At this time, the curvature of field and the uniform velocity of the beams 1 and 2 are as shown in FIG. 4, and the curvature of field of the beams 1 and 2 is particularly deteriorated in the sub-scanning. Also, S1 (+) = 0.92, S1 (-) =-0.73, S2 (+) = 1.37, S
2 (-) =-1.21, (S1 (+)-S1 (-)) × (S2 (+)-S2 (-)) = 4.257> 0, M1 (+) =-0.26, M1 (- ) = 0.21, M2 (+) =-0.79, M2 (-) = 0.19, and (M1 (+)-M1 (-)) × (M2 (+)-M2 (-)) = 0.461> 0 Neither of the conditional expressions (1) and (2) are satisfied.
【００２０】実施例２ 実施例１に対し下記の変更を行った。Example 2 The following changes were made to Example 1.
【００２１】Δ１＝０．８０ｍｍ，Δ２＝０．２５ｍ
ｍ，Δ１’＝０．８０ｍｍ，Δ２’＝０．２５ｍｍ。即
ち、請求項１に於けるシフトの条件は満たされている。
基準線Ｌ１、Ｌ２に対する走査レンズ１１のチルト量を
α、基準線Ｌ１、Ｌ２に対する走査レンズ１２のチルト
量をα'（反時計まわりを正）とすると、α＝−０．０
７度 ，α’＝０．４０度即ち、走査レンズ１１，１２
とも基準線Ｌ１，Ｌ２に対しチルトされている。シフト
とともにチルトを与えることにより、設計の自由度が増
し、条件式(１),(２)の条件を満たすことができ、良好
な光学特性が得られる。Δ1 = 0.80 mm, Δ2 = 0.25 m
m, Δ1 ′ = 0.80 mm, Δ2 ′ = 0.25 mm. That is, the shift condition in claim 1 is satisfied.
Assuming that the tilt amount of the scanning lens 11 with respect to the reference lines L1 and L2 is α and the tilt amount of the scanning lens 12 with respect to the reference lines L1 and L2 is α ′ (positive in the counterclockwise direction), α = −0.0
7 degrees, α ′ = 0.40 degrees, that is, the scanning lenses 11 and 12
Both are tilted with respect to the reference lines L1 and L2. By giving the tilt together with the shift, the degree of freedom of design is increased, the conditions of the conditional expressions (1) and (2) can be satisfied, and good optical characteristics can be obtained.
【００２２】実施例２の２ビームの主走査、副走査の像
面湾曲及び等速性を図５に示す。何れも良好に補正され
ている。また、S1(+)=-0.06，S1(-)=0.26，S2(+)=0.4
0，S2(-)=-0.22であって、 (S1(+)-S1(-))×(S2(+)-S2(-))=-0.20 ＜ 0 M1(+)=0.12，M1(-)=0.09，M2(+)=-0.20，M2(-)=0.14で
あって、 (M1(+)-M1(-))×(M2(+)-M2(-))=-0.01 ＜ 0 となり条件式(１)，(２)とも満足する。FIG. 5 shows the curvature of field and the uniform velocity of the main scanning and sub-scanning of the two beams according to the second embodiment. All are well corrected. Also, S1 (+) =-0.06, S1 (-) = 0.26, S2 (+) = 0.4
0, S2 (-) =-0.22, and (S1 (+)-S1 (-)) × (S2 (+)-S2 (-)) =-0.20 <0 M1 (+) = 0.12, M1 ( -) = 0.09, M2 (+) =-0.20, M2 (-) = 0.14, and (M1 (+)-M1 (-)) × (M2 (+)-M2 (-)) =-0.01 < 0, which satisfies both the conditional expressions (1) and (2).
【００２３】実施例３ 実施例１に対し下記の変更を行った。偏向反射面７によ
る反射ビームの主光線が基準線Ｌ１、Ｌ２と一致すると
きのビーム１のシリンダレンズ３から偏向反射面７まで
の距離：９１．９２ｍｍ、ビーム２のシリンダレンズ４
から偏向反射面７までの距離：９１．８８ｍｍ。ビーム
１が基準線Ｌ１と一致するとき、偏向反射面７上での２
ビームの距離は０．０ｍｍで、偏向回転面に２ビームを
射影すると偏向反射面上で交差する。Δ１＝０．８０ｍ
ｍ，Δ２＝０．７５ｍｍ，Δ１’＝０．８０ｍｍ，Δ
２’＝０．７５ｍｍで、請求項１における「第３光学系
の少なくとも１つの走査光学素子の光軸が上記全ての基
準線からみて、偏向反射面に向かうビーム側にシフトし
て配備される」との条件を満足する。Example 3 The following changes were made to Example 1. When the principal ray of the beam reflected by the deflecting / reflecting surface 7 matches the reference lines L1 and L2, the distance from the cylinder lens 3 of the beam 1 to the deflecting / reflecting surface 7: 91.92 mm, the cylinder lens 4 of the beam 2
From the mirror to the deflecting reflection surface 7: 91.88 mm. When the beam 1 coincides with the reference line L 1, 2
The distance between the beams is 0.0 mm. When two beams are projected on the deflecting rotation surface, they intersect on the deflecting reflection surface. Δ1 = 0.80m
m, Δ2 = 0.75 mm, Δ1 ′ = 0.80 mm, Δ
2 ′ = 0.75 mm, and the optical axis of at least one scanning optical element of the third optical system is shifted from the reference lines to the beam side toward the deflecting / reflecting surface. Is satisfied.
【００２４】チルト量：α＝−０．０６１度，α’＝
０．３５度である。 実施例３の２ビーム１，２に関する主・副走査方向の像
面湾曲及び等速性を図６に示す。これらは何れも良好に
補正されている。また、S1(+)=-0.02，S1(-)=0.22，S2
(+)=0.56，S2(-)=-0.12であり、 (S1(+)-S1(-))×(S2(+)-S2(-))=-0.16 ＜ 0 M1(+)=0.11，M1(-)=0.10，M2(+)=0.03，M2(-)=0.04であ
り、 (M1(+)-M1(-))×(M2(+)-M2(-))=-0.001 ＜ 0 となり条件式(１)，(２)とも満足する。上には光源とし
てＬＤ１，ＬＤ２の２つを用い、２ビームによる同時走
査の実施の形態を説明したが、３以上の光源を用いるこ
とができることは言うまでもない。３以上の光源を用い
る場合、各光源からのビームを偏向回転面に射影した状
態で、２以上のビームの主光線が互いに重なりあうよう
にすることができる。Tilt amount: α = −0.061 degrees, α ′ =
0.35 degrees. FIG. 6 shows the curvature of field and the constant velocity in the main and sub scanning directions for the two beams 1 and 2 of the third embodiment. These are all well corrected. Also, S1 (+) =-0.02, S1 (-) = 0.22, S2
(+) = 0.56, S2 (-) =-0.12, (S1 (+)-S1 (-)) × (S2 (+)-S2 (-)) =-0.16 <0 M1 (+) = 0.11 , M1 (-) = 0.10, M2 (+) = 0.03, M2 (-) = 0.04, and (M1 (+)-M1 (-)) × (M2 (+)-M2 (-)) =-0.001 <0, which satisfies both the conditional expressions (1) and (2). Although the embodiment of simultaneous scanning with two beams using two light sources LD1 and LD2 has been described above, it goes without saying that three or more light sources can be used. When three or more light sources are used, the principal rays of the two or more beams can be made to overlap each other in a state where the beams from each light source are projected on the deflection rotation surface.
【００２５】[0025]
【発明の効果】以上に説明したように、この発明によれ
ば新規なマルチビーム走査装置を実現できる。As described above, according to the present invention, a novel multi-beam scanning device can be realized.
【００２６】この発明のマルチビーム走査装置は、偏光
ビームスプリッタ等の高価なビーム合成手段を必要とせ
ず、少ない部品点数で安価に実現でき、各光源からのビ
ームに対して、像面湾曲や等速性等の特性を良好にする
ことができる。The multi-beam scanning apparatus according to the present invention does not require expensive beam combining means such as a polarizing beam splitter, and can be realized at a low cost with a small number of parts. Characteristics such as speed can be improved.
【００２７】請求項３〜５記載の発明によれば、条件
（１）および／または（２）を満足させることにより、
低コストに少ない部品点数で、複数のビームについて、
副走査方向および／または主走査方向の良好な像面湾曲
特性（小径で安定した副走査ビームスポット径）が得ら
れる。また、請求項６記載の発明によれば、光源側から
の複数ビームの偏向回転面内への射影で、少なくとも２
つのビームが偏向面以後で交差することにより、被走査
面上で２ビームが走査できる範囲の重なり部分を大きく
でき、偏向反射面が小さくても広い範囲の走査が可能に
なる。According to the present invention, by satisfying the conditions (1) and / or (2),
At low cost, with a small number of parts, multiple beams,
Good field curvature characteristics in the sub-scanning direction and / or main scanning direction (small and stable sub-scanning beam spot diameter) can be obtained. According to the sixth aspect of the present invention, the projection of the plurality of beams from the light source side into the plane of rotation for deflection is at least two.
When the two beams intersect after the deflecting surface, the overlapping portion of the scanable surface of the two beams can be increased, and a wide range of scanning can be performed even if the deflecting reflection surface is small.
【図１】この発明のマルチビーム走査装置の実施の１形
態を説明するための図である。FIG. 1 is a diagram for explaining an embodiment of a multi-beam scanning device according to the present invention.
【図２】第３光学系の走査結像素子のシフトの意義を説
明するための図である。FIG. 2 is a diagram for explaining the significance of a shift of a scanning imaging element of a third optical system.
【図３】実施例１のビーム１および２に関する像面湾曲
と等速性を示す図である。FIG. 3 is a diagram illustrating field curvature and constant velocity for beams 1 and 2 according to the first embodiment.
【図４】比較例１のビーム１および２に関する像面湾曲
と等速性を示す図である。FIG. 4 is a diagram showing field curvature and constant velocity for beams 1 and 2 of Comparative Example 1.
【図５】実施例２のビーム１および２に関する像面湾曲
と等速性を示す図である。FIG. 5 is a diagram illustrating field curvature and constant velocity for beams 1 and 2 according to a second embodiment.
【図６】実施例３のビーム１および２に関する像面湾曲
と等速性を示す図である。FIG. 6 is a diagram illustrating field curvature and constant velocity for beams 1 and 2 according to a third embodiment.
１，２ 光源であるＬＤ（半導体レーザ） ３，４ 第１光学系であるカップリングレンズ ５，６ 第２光学系であるシリンダレンズ ７ 偏向反射面 ７Ａ 偏向器の回転軸 １１，１２ 第３光学系の走査結像素子をなす走査
レンズ Ｌ１，Ｌ２ 基準線 Δ１，Δ２，Δ１’，Δ２’ シフト量1, LD (semiconductor laser) as a light source 3, 4 Coupling lens as a first optical system 5, 6 Cylinder lens as a second optical system 7 Deflection / reflection surface 7A Rotation axis of deflector 11, 12 Third optics Lenses L1, L2 which form the scanning imaging element of the system Reference lines Δ1, Δ2, Δ1 ′, Δ2 ′ Shift amount
Claims (6)
１光学系と、 該第一光学系からのビームを、主走査方向に長く略線状
に集光する第２光学系と、 上記略線状の集光部の近傍に偏向反射面を有し、上記第
２光学系からの複数ビームを等角速度的に偏向し、上記
偏向反射面とその回転軸が一定距離離れている偏向器
と、 該偏向器により偏向された複数の偏向ビームを被走査面
に向けて集光させ、被走査面を略等速的に走査する走査
結像素子を含む第３光学系とを有し、 上記第２光学系からの複数のビームは、走査結像素子の
外側の同じ側から偏向反射面に向かい、 上記第２光学系からの複数のビームのうち少なくとも２
つは偏向回転面内で開き角を有し、且つ、 上記偏向器による複数の偏向ビームの主光線が被走査面
上の走査ラインと直交するときの該各主光線を基準線と
するとき、第３光学系の少なくとも１つの走査光学素子
の光軸が上記全ての基準線からみて、偏向反射面に向か
うビーム側にシフトして配備されることを特徴とするマ
ルチビーム走査装置。1. A plurality of light sources, a plurality of first optical systems respectively coupling the plurality of light sources, and a first optical system which condenses a beam from the first optical system in a substantially linear shape in a main scanning direction. A second optical system, and a deflecting / reflecting surface in the vicinity of the substantially linear condensing portion, which deflects a plurality of beams from the second optical system at a constant angular velocity, and wherein the deflecting / reflecting surface and its rotation axis are constant. A third optical system including a deflector separated by a distance, and a scanning imaging element that converges a plurality of deflection beams deflected by the deflector toward a surface to be scanned and scans the surface to be scanned at a substantially constant speed. A plurality of beams from the second optical system are directed to the deflecting / reflecting surface from the same side outside the scanning image forming element, and at least two beams out of the plurality of beams from the second optical system are provided.
One has an opening angle in the deflecting rotation plane, and, when the principal rays of the plurality of deflection beams by the deflector are orthogonal to scanning lines on the surface to be scanned, each principal ray is used as a reference line, A multi-beam scanning device, wherein the optical axis of at least one scanning optical element of the third optical system is arranged shifted to the beam side toward the deflecting reflection surface when viewed from all the reference lines.
いて、 第３光学系の、少なくとも１つの走査光学素子が基準線
に対して、チルトして配備されることを特徴とするマル
チビーム走査装置。2. The multi-beam scanning apparatus according to claim 1, wherein at least one scanning optical element of the third optical system is disposed at a tilt with respect to a reference line. .
１光学系と、 該第一光学系からのビームを、主走査方向に長く略線状
に集光する第２光学系と、 上記略線状の集光部の近傍に偏向反射面を有し、上記第
２光学系からの複数ビームを等角速度的に偏向し、上記
偏向反射面とその回転軸が一定距離離れている偏向器
と、 上記偏向された複数の偏向ビームを被走査面に向けて集
光させ、被走査面を略等速的に走査する走査結像素子を
含む第３光学系とを有し、 上記第２光学系からの複数のビームは、走査結像素子の
外側の同じ側から偏向反射面に向かい、 上記第２光学系からの複数のビームのうち少なくとも２
つは偏向回転面内で開き角を有し、 上記複数の光源によるビームのうちの１つのビームの両
最周辺像高での副走査方向結像位置をS1(+)，S1(-)、上
記以外の１つの光源によるビームの両最周辺像高での副
走査方向結像位置をS2(+)，S2(-)とするとき、これらが
条件： （１） (S1(+)-S1(-))×(S2(+)-S2(-))＜0 を満足することを特徴とするマルチビーム走査装置。3. A plurality of light sources, a plurality of first optical systems respectively coupling the plurality of light sources, and a first optical system which condenses a beam from the first optical system into a substantially linear shape long in the main scanning direction. A second optical system, and a deflecting / reflecting surface in the vicinity of the substantially linear condensing portion, which deflects a plurality of beams from the second optical system at a constant angular velocity, and wherein the deflecting / reflecting surface and its rotation axis are constant. A deflector separated by a distance, and a third optical system including a scanning imaging element that condenses the plurality of deflected deflection beams toward the surface to be scanned and scans the surface to be scanned at a substantially constant speed. A plurality of beams from the second optical system are directed to the deflecting / reflecting surface from the same side outside the scanning image forming element, and at least two of the plurality of beams from the second optical system are provided.
One has an opening angle in the deflection rotation plane, and S1 (+), S1 (-), S1 (+), S1 (-), When the image forming positions in the sub-scanning direction at both extreme image heights of the beam by one light source other than those described above are S2 (+) and S2 (-), these conditions are as follows: (1) (S1 (+)-S1 A multi-beam scanning apparatus characterized by satisfying (−)) × (S2 (+) − S2 (−)) <0.
１光学系と、 該第一光学系からのビームを、主走査方向に長く略線状
に集光する第２光学系と、 上記略線状の集光部の近傍に偏向反射面を有し、上記第
２光学系からの複数ビームを等角速度的に偏向し、上記
偏向反射面とその回転軸が一定距離離れている偏向器
と、 上記偏向された複数の偏向ビームを被走査面に向けて集
光させ、被走査面を略等速的に走査する走査結像素子を
含む第３光学系とを有し、 上記第２光学系からの複数のビームは、走査結像素子の
外側の同じ側から偏向反射面に向かい、 上記第２光学系からの複数のビームのうち少なくとも２
つは偏向回転面内で開き角を有し、 上記複数の光源によるビームのうちの１つのビームの両
最周辺像高での主走査方向結像位置をM1(+)，M1(-)、上
記以外の１つの光源によるビームの両最周辺像高での主
走査方向結像位置をM2(+)，M2(-)とするとき、これらが
条件： （２） (M1(+)-M1(-))×(M2(+)-M2(-))＜0 を満足することを特徴とするマルチビーム走査装置。4. A plurality of light sources, a plurality of first optical systems respectively coupling the plurality of light sources, and a first optical system for condensing a beam from the first optical system into a substantially linear shape long in the main scanning direction. A second optical system, and a deflecting / reflecting surface in the vicinity of the substantially linear condensing portion, which deflects a plurality of beams from the second optical system at a constant angular velocity, and wherein the deflecting / reflecting surface and its rotation axis are constant. A deflector separated by a distance, and a third optical system including a scanning imaging element that condenses the plurality of deflected deflection beams toward the surface to be scanned and scans the surface to be scanned at a substantially constant speed. A plurality of beams from the second optical system are directed to the deflecting / reflecting surface from the same side outside the scanning image forming element, and at least two of the plurality of beams from the second optical system are provided.
One has an opening angle in the plane of rotation of deflection, and M1 (+), M1 (-), M1 (+), M1 (-), When the image forming positions in the main scanning direction at both extreme image heights of the beam by one light source other than the above are M2 (+) and M2 (-), these conditions are as follows: (2) (M1 (+)-M1 A multi-beam scanning device characterized by satisfying (−)) × (M2 (+) − M2 (−)) <0.
１光学系と、 該第一光学系からのビームを、主走査方向に長く略線状
に集光する第２光学系と、 上記略線状の集光部の近傍に偏向反射面を有し、上記第
２光学系からの複数ビームを等角速度的に偏向し、上記
偏向反射面と回転軸が一定距離離れている偏向器と、 上記偏向された複数の偏向ビームを被走査面に向けて集
光させ、被走査面を略等速的に走査する走査結像素子を
含む第３光学系とを有し、 上記第２光学系からの複数のビームは、走査結像素子の
外側の同じ側から偏向反射面に向かい、 上記第２光学系からの複数のビームのうち少なくとも２
つは偏向回転面内で開き角を有し、 上記複数の光源によるビームのうちの１つのビームの両
最周辺像高での主走査方向結像位置をM1(+)，M1(-)、副
走査方向結像位置をS1(+)，S1(-)、上記以外の１つの光
源によるビームの両最周辺像高での主走査方向結像位置
をM2(+)，M2(-)、副走査方向結像位置をS2(+),S2(-)と
するとき、これらが条件： （１） (S1(+)-S1(-))×(S2(+)-S2(-))＜0 （２） (M1(+)-M1(-))×(M2(+)-M2(-))＜0 を共に満足することを特徴とするマルチビーム走査装
置。5. A plurality of light sources, a plurality of first optical systems respectively coupling the plurality of light sources, and a first optical system which condenses a beam from the first optical system into a substantially linear shape long in the main scanning direction. A second optical system, and a deflecting / reflecting surface in the vicinity of the substantially linear condensing portion, for deflecting a plurality of beams from the second optical system at a constant angular velocity, wherein the deflecting / reflecting surface and the rotation axis are separated by a predetermined distance. And a third optical system including a scanning imaging element that converges the plurality of deflected deflection beams toward the surface to be scanned and scans the surface to be scanned at a substantially constant speed. The plurality of beams from the second optical system travel from the same side outside the scanning image forming element to the deflecting / reflecting surface, and at least two beams out of the plurality of beams from the second optical system.
One has an opening angle in the plane of rotation of deflection, and M1 (+), M1 (-), M1 (+), M1 (-), S1 (+) and S1 (-) are imaging positions in the sub-scanning direction, and M2 (+), M2 (-) and M2 (+) are imaging positions in the main scanning direction at both outermost image heights of the beam by one light source other than the above. When the imaging positions in the sub-scanning direction are S2 (+) and S2 (-), these conditions are as follows: (1) (S1 (+)-S1 (-)) × (S2 (+)-S2 (-)) <0 (2) A multi-beam scanning apparatus characterized by satisfying both (M1 (+)-M1 (-)) * (M2 (+)-M2 (-)) <0.
チビーム走査装置において、 偏向回転面内に射影した場合、少なくとも２つのビーム
が偏向面以後で交差することを特徴とするマルチビーム
走査装置。6. The multi-beam scanning apparatus according to claim 1, wherein at least two beams intersect after the deflecting surface when projected onto the deflecting rotation surface. Scanning device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15611998A JP3619672B2 (en) | 1998-06-04 | 1998-06-04 | Multi-beam scanning device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15611998A JP3619672B2 (en) | 1998-06-04 | 1998-06-04 | Multi-beam scanning device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11352426A true JPH11352426A (en) | 1999-12-24 |
| JP3619672B2 JP3619672B2 (en) | 2005-02-09 |
Family
ID=15620744
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15611998A Expired - Fee Related JP3619672B2 (en) | 1998-06-04 | 1998-06-04 | Multi-beam scanning device |
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| Country | Link |
|---|---|
| JP (1) | JP3619672B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6882404B2 (en) | 2002-07-25 | 2005-04-19 | Canon Kabushiki Kaisha | Scanning optical device and image forming apparatus using the same |
| JP2006323277A (en) * | 2005-05-20 | 2006-11-30 | Konica Minolta Business Technologies Inc | Optical scanner |
| JP2015222336A (en) * | 2014-05-22 | 2015-12-10 | 株式会社リコー | Optical scanner and image forming apparatus |
-
1998
- 1998-06-04 JP JP15611998A patent/JP3619672B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6882404B2 (en) | 2002-07-25 | 2005-04-19 | Canon Kabushiki Kaisha | Scanning optical device and image forming apparatus using the same |
| JP2006323277A (en) * | 2005-05-20 | 2006-11-30 | Konica Minolta Business Technologies Inc | Optical scanner |
| JP2015222336A (en) * | 2014-05-22 | 2015-12-10 | 株式会社リコー | Optical scanner and image forming apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3619672B2 (en) | 2005-02-09 |
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