JP2001021819A - Scanning optical device - Google Patents
Scanning optical deviceInfo
- Publication number
- JP2001021819A JP2001021819A JP11189154A JP18915499A JP2001021819A JP 2001021819 A JP2001021819 A JP 2001021819A JP 11189154 A JP11189154 A JP 11189154A JP 18915499 A JP18915499 A JP 18915499A JP 2001021819 A JP2001021819 A JP 2001021819A
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- Japan
- Prior art keywords
- optical
- scanning
- light beam
- incident
- angle
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Links
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- Laser Beam Printer (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Facsimile Scanning Arrangements (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は走査光学装置（マル
チビーム走査光学装置）に関し、特に複数の発光部を有
する光源手段から出射された複数の光束を回転多面鏡よ
り成る光偏向器で偏向させた後、ｆθ特性を有する結像
光学系（走査光学手段）を介して被走査面上を同時に光
走査して画像情報を記録するようにした、例えば電子写
真プロセスを有するレーザービームプリンター（ＬＢ
Ｐ）やデジタル複写機等の装置に好適なものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning optical device (multi-beam scanning optical device), and more particularly to deflecting a plurality of light beams emitted from light source means having a plurality of light emitting portions by an optical deflector comprising a rotating polygon mirror. After that, a laser beam printer (LB having an electrophotographic process, for example) is configured to simultaneously perform optical scanning on the surface to be scanned through an imaging optical system (scanning optical means) having fθ characteristics to record image information.
P) or a device such as a digital copying machine.
【０００２】[0002]
【従来の技術】従来よりレーザービームプリンターやデ
ジタル複写機等の画像形成装置に用いられる走査光学装
置においては画像信号に応じて光源手段から光変調され
出射した光束を、例えば回転多面鏡（ポリゴンミラー）
より成る光偏向器により周期的に偏向させ、ｆθ特性を
有する結像光学系（走査光学手段）によって感光性の記
録媒体（感光ドラム）面上にスポット状に集束させ、そ
の面上を光走査して画像記録を行っている。2. Description of the Related Art Conventionally, in a scanning optical device used in an image forming apparatus such as a laser beam printer or a digital copying machine, a light beam emitted from a light source means after being modulated in accordance with an image signal is output to, for example, a rotating polygon mirror (polygon mirror). )
The light is periodically deflected by an optical deflector made of light, focused by an imaging optical system (scanning optical means) having fθ characteristics into a spot on a photosensitive recording medium (photosensitive drum) surface, and optically scanned on the surface. Image recording.
【０００３】更に近年は高速化の要求から、被走査面上
を同時に光走査する光束の数を複数にする、所謂マルチ
ビーム走査光学装置が種々と提案されている。In recent years, in response to a demand for higher speed, various types of so-called multi-beam scanning optical devices have been proposed in which the number of light beams that simultaneously scan the surface to be scanned is plural.
【０００４】図９は従来のマルチビーム走査光学装置の
要部概略図である。FIG. 9 is a schematic view of a main part of a conventional multi-beam scanning optical device.
【０００５】同図において複数の発光部を有する光源手
段（マルチ半導体レーザー）９１から出射した複数の発
散光束はコリメーターレンズ９２により略平行光束とさ
れ、絞り９３によって該光束を制限して、副走査方向に
のみ所定の屈折力を有するシリンドリカルレンズ９４に
入射している。シリンドリカルレンズ９４に入射した略
平行光束のうち主走査断面内においてはそのまま略平行
光束の状態で射出する。また副走査断面内においては集
束して回転多面鏡（ポリゴンミラー）から成る光偏向器
９５の偏向面（反射面）９５ａにほぼ線像として結像し
ている。そして光偏向器９５の偏向面９５ａで偏向され
た複数の光束はｆθ特性を有する結像光学系（走査光学
手段）９６により被走査面としての感光ドラム面９７上
に結像させ、該光偏向器９５を矢印Ａ方向に回転させる
ことによって、該感光ドラム面９７上を矢印Ｂ方向（主
走査方向）に同時に光走査して画像情報の記録を行なっ
ている。In FIG. 1, a plurality of divergent light beams emitted from a light source means (multi-semiconductor laser) 91 having a plurality of light-emitting portions are converted into substantially parallel light beams by a collimator lens 92, and the light beams are restricted by a stop 93, The light is incident on a cylindrical lens 94 having a predetermined refractive power only in the scanning direction. Of the substantially parallel light beams incident on the cylindrical lens 94, they are emitted as they are in the state of substantially parallel light beams in the main scanning section. In the sub-scan section, the light is converged and formed as a substantially linear image on the deflection surface (reflection surface) 95a of the optical deflector 95 formed of a rotating polygon mirror (polygon mirror). The plurality of light beams deflected by the deflecting surface 95a of the optical deflector 95 are imaged on a photosensitive drum surface 97 as a surface to be scanned by an imaging optical system (scanning optical means) 96 having fθ characteristics. By rotating the unit 95 in the direction of arrow A, the photosensitive drum surface 97 is simultaneously optically scanned in the direction of arrow B (main scanning direction) to record image information.
【０００６】このとき感光ドラム面９７上を光走査する
前に該感光ドラム面９７上の走査開始位置のタイミング
を調整する為に光偏向器９５で偏向された光束の一部で
あるＢＤ光束（同期検知用の光束）９８をＢＤミラー
（同期検知用ミラー）９９で反射させてＢＤセンサー
（同期検知用センサー）１００に導光している。そして
ＢＤセンサー１００からの出力信号を検知して得られた
ＢＤ信号を用いて感光ドラム面９７上への画像記録の走
査開始位置のタイミングを調整している。At this time, before optical scanning on the photosensitive drum surface 97, a BD light beam (part of the light beam deflected by the optical deflector 95 to adjust the timing of the scanning start position on the photosensitive drum surface 97 is adjusted. The light flux 98 for synchronization detection is reflected by a BD mirror (mirror for synchronization detection) 99 and guided to a BD sensor (sensor for synchronization detection) 100. The timing of the scanning start position of the image recording on the photosensitive drum surface 97 is adjusted using the BD signal obtained by detecting the output signal from the BD sensor 100.
【０００７】尚、ここで主走査方向とは偏向走査方向に
平行な方向、副走査方向とは偏向走査方向に垂直な方向
である。Here, the main scanning direction is a direction parallel to the deflection scanning direction, and the sub-scanning direction is a direction perpendicular to the deflection scanning direction.
【０００８】[0008]
【発明が解決しようとする課題】複数の光束を同時に光
走査させるマルチビーム走査光学装置の場合、被走査面
である感光ドラム面上における各走査線の間隔を均一に
する必要がある。１回の走査における被走査面上での複
数の光束による走査線の間隔は、全像高において均一で
なければならない。例えば各走査線ごとに異なる傾きや
湾曲が生じ、走査線間隔が像高ごとに変化し不均一にな
るとピッチムラが発生し良好なる画像が得られなくな
る。In the case of a multi-beam scanning optical apparatus for simultaneously scanning a plurality of light beams, it is necessary to make the intervals between the scanning lines uniform on the surface of the photosensitive drum which is the surface to be scanned. The interval between scanning lines formed by a plurality of light beams on the surface to be scanned in one scan must be uniform at the entire image height. For example, if each scanning line has a different inclination or curvature, and the scanning line interval changes at each image height and becomes non-uniform, pitch unevenness occurs and a good image cannot be obtained.
【０００９】また全像高において走査線間隔が均一であ
っても、所望の解像度に合った間隔にはなっていない場
合、感光ドラムは所望の解像度に合わせて一定角速度で
回転しているため、ピッチムラが発生し、良好なる画像
を得ることができなくなる。つまり１回の走査における
走査線間隔と各走査間における走査線間隔が異なり、ピ
ッチムラが発生する。If the scanning line spacing is uniform at all image heights but does not match the desired resolution, the photosensitive drum rotates at a constant angular velocity in accordance with the desired resolution. Pitch unevenness occurs, and a good image cannot be obtained. That is, the scanning line interval in one scan differs from the scanning line interval between each scan, and pitch unevenness occurs.
【００１０】しかしながら後者の問題点に関しては複数
の発光部（発光点）を有する光源の配置を調整すること
により解決することが可能である。即ち被走査面である
感光ドラム面上における走査線間隔を所望の値になるよ
うに光源の配置を調整することにより補正することがで
きる。例えば発光部の離れた２つの光束を射出する光源
を用いる場合、入射光学手段の光軸を中心に該光源を回
転させることにより、副走査断面内において該光軸に対
する各発光部の距離を所望の距離に配置することがで
き、これにより所望の調整が成される。However, the latter problem can be solved by adjusting the arrangement of a light source having a plurality of light emitting portions (light emitting points). That is, the distance between the scanning lines on the surface of the photosensitive drum, which is the surface to be scanned, can be corrected by adjusting the arrangement of the light sources so as to have a desired value. For example, in the case of using a light source that emits two light beams separated from the light emitting unit, by rotating the light source around the optical axis of the incident optical unit, the distance between each light emitting unit and the optical axis in the sub-scanning cross section is desired. At a distance, which provides the desired adjustment.
【００１１】しかしながら前者の問題点に関しては各光
学素子、偏向手段等の加工誤差、光学素子を組み付ける
光学箱の加工誤差、あるいは走査光学装置の組立て誤差
等があると像高による走査線間隔の不均一性が発生して
しまう。マルチビームを発生させる光源は現状、熱的ク
ロストーク等の影響のため発光部の間隔をある間隔（９
０μｍ程度）以上短くすることができず、また上記調整
により光源を光軸中心に所望の角度回転させる場合、例
えば２つの発光部は主走査断面内においてもある間隔を
持って配置される。したがって開口絞りを射出した２つ
の光束は相対的にある角度を持ってその後の偏向手段、
走査光学手段等に入射することになる。走査光学手段に
入射する２つの光束は主走査断面内において離れた位置
に入射し、且つ入射角も異なる。また副走査断面内にお
いても発光部は光軸に対し離れた位置に配置されるた
め、ある角度を持って走査光学手段に入射する。However, regarding the former problem, if there is a processing error of each optical element, deflection means, etc., a processing error of an optical box for assembling the optical element, or an assembly error of the scanning optical device, the scanning line interval may not be improved due to the image height. Uniformity occurs. At present, a light source for generating a multi-beam has an interval between light emitting units (9) due to the influence of thermal crosstalk or the like.
When the light source is rotated by a desired angle around the optical axis by the above adjustment, for example, the two light emitting units are arranged at a certain interval even in the main scanning section. Therefore, the two light beams emitted from the aperture stop have a certain angle relatively to the subsequent deflection means,
The light enters the scanning optical means and the like. The two light beams incident on the scanning optical unit are incident on distant positions in the main scanning section and have different incident angles. In addition, since the light emitting section is disposed at a position distant from the optical axis also in the sub-scan section, the light enters the scanning optical means at a certain angle.
【００１２】ここで各光学素子等の加工誤差、走査光学
装置の組立て誤差等があると２つの光束の入射位置、入
射角の差も大きなものとなり、光路長差が発生する。こ
のとき２つの光束の入射面におけるパワーも異なるため
副走査断面内における２つの光束の屈折角も異なり、像
高ごとに走査線の間隔誤差が発生してしまうことにな
る。Here, if there is a processing error of each optical element, an assembling error of the scanning optical device, etc., the difference between the incident positions and the incident angles of the two light beams becomes large, and an optical path length difference occurs. At this time, since the powers of the two light beams on the incident surface are also different, the refraction angles of the two light beams in the sub-scanning cross section are also different, and a scanning line interval error occurs for each image height.
【００１３】特に近年は高精細化のため走査光学手段の
主走査方向の形状を非球面化したり、副走査方向の曲率
半径を光軸から離れるに従い変化させる構成を用いる場
合、２つの光束の光路長差、入射面におけるパワー差も
より大きなものとなり、走査線の間隔誤差も顕著にな
る。Particularly, in recent years, when using a configuration in which the shape of the scanning optical means in the main scanning direction is made aspherical or the radius of curvature in the sub-scanning direction is changed as the distance from the optical axis increases, the optical path of the two light beams is increased. The difference in length and the difference in power at the entrance surface are also larger, and the error in the spacing between the scanning lines becomes significant.
【００１４】このような走査線間隔誤差を補正する手段
として主走査方向の光束幅を規制する開口絞りをより偏
向手段側に配置し、偏向手段及び走査光学手段に入射す
る光束間の入射角差を小さく抑えるようにした走査光学
装置が、例えば特開平５−３４６１３号公報等で提案さ
れている。開口絞りが偏向手段に近ければ近いほど、該
開口絞りを射出する複数光束の射出角差は小さなものと
なる。このことにより、走査光学手段に入射する複数光
束の入射位置、入射角の差も小さくすることが可能とな
り、走査線の間隔誤差を抑えることができる。As a means for correcting such a scanning line interval error, an aperture stop for restricting the light beam width in the main scanning direction is arranged closer to the deflecting means, and the angle of incidence difference between the light beams incident on the deflecting means and the scanning optical means. A scanning optical device that suppresses the noise has been proposed, for example, in Japanese Patent Application Laid-Open No. 5-34613. The closer the aperture stop is to the deflecting means, the smaller the difference between the exit angles of a plurality of light beams exiting the aperture stop. This makes it possible to reduce the difference between the incident positions and the incident angles of a plurality of light beams incident on the scanning optical unit, and it is possible to suppress a scanning line interval error.
【００１５】しかしながら主走査方向の光束幅を規制す
る開口絞りを偏向手段近傍に配置すると、該開口絞りと
走査光学手段を構成する光学素子の間隔が狭くなり、空
間的な余裕が少なくなる。近年においては走査光学装置
の小型化の要求から走査角の広画角化、光学素子を偏向
手段の近傍に配置する構成をしており、この場合空間的
な余裕は更に小さくなる。However, if an aperture stop that regulates the light beam width in the main scanning direction is arranged near the deflecting means, the space between the aperture stop and the optical element that constitutes the scanning optical means is narrowed, and the space margin is reduced. In recent years, there has been a configuration in which the scanning angle is widened and the optical element is arranged near the deflecting means in response to a demand for miniaturization of the scanning optical device. In this case, the space margin is further reduced.
【００１６】ここで走査光学手段の光軸に対し入射光学
手段と同一の方向で、且つ入射光学手段の光軸に対し走
査光学手段側でＢＤ光束（同期検知用の光束）を取ろう
とした場合、開口絞りに該ＢＤ光束が蹴られ、ＢＤセン
サーに導光される光量が減少することにより、該ＢＤセ
ンサーからのＢＤ信号の出力の精度が落ちたり、また全
ての同期検知用の光束が蹴られＢＤセンサーに光束が導
光されず、ＢＤ信号が全く得られなくなる可能性があ
る。また蹴られた光束がフレアとなって感光ドラム面上
に導光され画像に悪影響を及ぼしたり、光源に光束が戻
り、光出力変動を生じさせる可能性もある。Here, when an attempt is made to take a BD light beam (a light beam for synchronization detection) in the same direction as the incident optical unit with respect to the optical axis of the scanning optical unit and on the scanning optical unit side with respect to the optical axis of the incident optical unit. Since the BD light beam is kicked by the aperture stop and the amount of light guided to the BD sensor is reduced, the accuracy of the output of the BD signal from the BD sensor is reduced, and all the light beams for synchronization detection are kicked. As a result, the luminous flux is not guided to the BD sensor, and there is a possibility that a BD signal cannot be obtained at all. Further, the kicked light beam may be flare and guided on the surface of the photosensitive drum to adversely affect the image, or the light beam may return to the light source to cause a change in light output.
【００１７】本発明は走査光学装置を構成する各要素を
適切に設定することにより、開口絞りを偏向手段近傍に
配置した場合でも、同期検知用の光束が該開口絞りに蹴
られることなく十分確保することができ、高精細な印字
が可能なコンパクトな走査光学装置の提供を目的とす
る。According to the present invention, even when the aperture stop is arranged near the deflecting means, the light beam for synchronization detection can be sufficiently secured without being kicked by the aperture stop by appropriately setting each element constituting the scanning optical device. It is an object of the present invention to provide a compact scanning optical device capable of performing high-definition printing.
【００１８】[0018]
【課題を解決するための手段】請求項１の発明の走査光
学装置は、複数の発光部を有する光源手段から出射した
複数の光束を主走査方向に長い線状の光束として結像さ
せる入射光学手段と、該入射光学手段の結像位置近傍に
偏向面を有し、入射された複数の光束を主走査方向に偏
向走査する偏向手段と、該偏向手段で偏向された複数の
光束を被走査面上に結像させる走査光学手段と、該偏向
手段で偏向された光束の一部である同期検知用の光束を
用いて該被走査面上の走査開始位置のタイミングを制御
する同期検知手段と、を有する走査光学装置において、
該入射光学手段を構成する複数の光学素子のうち、最も
偏向手段側にある光学素子と該偏向手段との間の光路内
に少なくとも１つの開口絞りを配置しており、該偏向手
段による偏向直後の該同期検知用の光束は該走査光学手
段の光軸に対し、該入射光学手段側とは反対側の領域を
通過する光束の一部を用いたことを特徴としている。According to a first aspect of the present invention, there is provided a scanning optical apparatus which forms an image of a plurality of light beams emitted from a light source having a plurality of light-emitting portions as a long linear light beam in a main scanning direction. Means, a deflecting means having a deflecting surface in the vicinity of the image forming position of the incident optical means, and deflecting and scanning the plurality of incident light beams in the main scanning direction; and scanning the plurality of light beams deflected by the deflecting means. Scanning optical means for forming an image on a surface, synchronization detection means for controlling the timing of a scanning start position on the surface to be scanned by using a light beam for synchronization detection which is a part of the light beam deflected by the deflecting means; A scanning optical device having
At least one aperture stop is arranged in an optical path between the optical element closest to the deflecting means and the deflecting means among the plurality of optical elements constituting the incident optical means, and immediately after deflection by the deflecting means. The light beam for synchronization detection is characterized in that a part of the light beam passing through a region on the side opposite to the incident optical unit side with respect to the optical axis of the scanning optical unit is used.
【００１９】請求項２の発明は請求項１の発明におい
て、前記走査光学手段の光軸と前記入射光学手段の光軸
との成す角をα、該走査光学手段の光軸と該偏向手段に
よる偏向直後の同期検知用の光束との成す角をβとした
とき、 −β＜α （角度の符号は走査光学手段の光軸に対し入射光学手段
側に測った角度を＋とする。）なる条件を満足すること
を特徴としている。According to a second aspect of the present invention, in the first aspect, the angle between the optical axis of the scanning optical means and the optical axis of the incident optical means is α, and the angle formed by the optical axis of the scanning optical means and the deflecting means. Assuming that the angle formed by the synchronization detection light beam immediately after deflection is β, −β <α (the sign of the angle is + when the angle measured on the incident optical means side with respect to the optical axis of the scanning optical means). It is characterized by satisfying the conditions.
【００２０】請求項３の発明は請求項１の発明におい
て、前記走査光学手段の光軸と前記入射光学手段の光軸
との成す角をα、該走査光学手段の光軸と該偏向手段に
よる偏向直後の同期検知用の光束との成す角をβとした
とき、 −β＜α≦９０° （角度の符号は走査光学手段の光軸に対し入射光学手段
側に測った角度を＋とする。）なる条件を満足すること
を特徴としている。According to a third aspect of the present invention, in the first aspect, the angle between the optical axis of the scanning optical means and the optical axis of the incident optical means is α, and the angle formed by the optical axis of the scanning optical means and the deflecting means. When the angle between the light beam for synchronization detection immediately after deflection is β, −β <α ≦ 90 ° (the sign of the angle is + when the angle measured on the incident optical means side with respect to the optical axis of the scanning optical means) .) Are satisfied.
【００２１】請求項４の発明は請求項１の発明におい
て、前記偏向直後の同期検知用の光束は走査画角の１／
２より大きい範囲を通過することを特徴としている。According to a fourth aspect of the present invention, in the first aspect of the present invention, the light beam for synchronization detection immediately after the deflection is 1/1 of the scanning field angle.
It is characterized by passing through a range greater than 2.
【００２２】請求項５の発明は請求項１の発明におい
て、前記少なくとも１つの開口絞りは主走査方向と副走
査方向の双方の光束幅を規制していることを特徴として
いる。According to a fifth aspect of the present invention, in the first aspect, the at least one aperture stop regulates a light beam width in both the main scanning direction and the sub-scanning direction.
【００２３】請求項６の発明は請求項１の発明におい
て、前記少なくとも１つの開口絞りは主走査方向の光束
幅を規制していることを特徴としている。According to a sixth aspect of the present invention, in the first aspect, the at least one aperture stop regulates a light beam width in the main scanning direction.
【００２４】請求項７の発明は請求項１の発明におい
て、前記少なくとも１つの開口絞りは主走査方向の光束
幅を規制し、前記入射光学手段はコリメーターレンズを
有し、該コリメーターレンズの近傍に副走査方向の光束
幅を規制する開口絞りを配置したことを特徴としてい
る。According to a seventh aspect of the present invention, in the first aspect, the at least one aperture stop regulates a light beam width in the main scanning direction, the incident optical means has a collimator lens, and An aperture stop that regulates the light beam width in the sub-scanning direction is arranged in the vicinity.
【００２５】請求項８の発明の走査光学装置は、複数の
発光部を有する光源手段から出射した複数の光束を主走
査方向に長い線状の光束として結像させる入射光学手段
と、該入射光学手段の結像位置近傍に偏向面を有し、入
射された複数の光束を主走査方向に偏向走査する偏向手
段と、該偏向手段で偏向された複数の光束を被走査面上
に結像させる走査光学手段と、該偏向手段で偏向された
光束の一部である同期検知用の光束を用いて該被走査面
上の走査開始位置のタイミングを制御する同期検知手段
と、を有する走査光学装置において、該入射光学手段を
構成する複数の光学素子のうち、最も偏向手段側にある
光学素子と該偏向手段との間の光路内に少なくとも１つ
の開口絞りを配置しており、該偏向手段による偏向直後
の該同期検知用の光束は該入射光学手段の光軸に対し該
走査光学手段側とは反対側の領域を通過する光束の一部
を用いたことを特徴としている。The scanning optical apparatus according to the present invention is an incident optical means for forming an image of a plurality of light beams emitted from a light source means having a plurality of light emitting portions as a linear light beam long in the main scanning direction, and the incident optical means. A deflecting means having a deflecting surface near an image forming position of the means for deflecting and scanning a plurality of incident light beams in the main scanning direction, and forming an image of the plurality of light beams deflected by the deflecting means on a surface to be scanned A scanning optical device comprising: scanning optical means; and synchronization detecting means for controlling timing of a scanning start position on the surface to be scanned by using a light beam for synchronization detection which is a part of the light beam deflected by the deflecting means. Wherein at least one aperture stop is arranged in an optical path between the optical element closest to the deflecting means and the deflecting means among the plurality of optical elements constituting the incident optical means. For synchronization detection immediately after deflection Bundle is characterized by using a part of the light flux passing through an area opposite to the said scanning optical means side with respect to the optical axis of said incident optical means.
【００２６】請求項９の発明は請求項８の発明におい
て、前記走査光学手段の光軸と前記入射光学手段の光軸
との成す角をα、該走査光学手段の光軸と該偏向手段に
よる偏向直後の同期検知用の光束との成す角をβとした
とき、 α＜β （角度の符号は走査光学手段の光軸に対し入射光学手段
側に測った角度を＋とする。）なる条件を満足すること
を特徴としている。According to a ninth aspect of the present invention, in the eighth aspect, the angle between the optical axis of the scanning optical means and the optical axis of the incident optical means is α, and the angle formed by the optical axis of the scanning optical means and the deflecting means is Assuming that the angle formed by the light beam for synchronization detection immediately after deflection is β, the condition α <β (the sign of the angle is + for the angle measured on the incident optical means side with respect to the optical axis of the scanning optical means). Is satisfied.
【００２７】請求項１０の発明は請求項８の発明におい
て、前記走査光学手段の光軸と前記入射光学手段の光軸
との成す角をα、該走査光学手段の光軸と該偏向手段に
よる偏向直後の同期検知用の光束との成す角をβとした
とき、 ０．５β＜α＜β （角度の符号は走査光学手段の光軸に対し入射光学手段
側に測った角度を＋とする。）なる条件を満足すること
を特徴としている。According to a tenth aspect of the present invention, in the invention of the eighth aspect, the angle between the optical axis of the scanning optical means and the optical axis of the incident optical means is α, and the angle formed by the optical axis of the scanning optical means and the deflecting means. When the angle formed with the light beam for synchronization detection immediately after the deflection is β, 0.5β <α <β (the sign of the angle is + with the angle measured on the incident optical means side with respect to the optical axis of the scanning optical means) .) Are satisfied.
【００２８】請求項１１の発明は請求項８の発明におい
て、前記少なくとも１つの開口絞りは主走査方向と副走
査方向の双方の光束幅を規制していることを特徴として
いる。An eleventh invention is characterized in that, in the eighth invention, the at least one aperture stop regulates the light beam width in both the main scanning direction and the sub-scanning direction.
【００２９】請求項１２の発明は請求項８の発明におい
て、前記少なくとも１つの開口絞りは主走査方向の光束
幅を規制していることを特徴としている。A twelfth aspect of the present invention is characterized in that, in the eighth aspect of the present invention, the at least one aperture stop regulates a light beam width in the main scanning direction.
【００３０】請求項１３の発明は請求項８の発明におい
て、前記少なくとも１つの開口絞りは主走査方向の光束
幅を規制し、前記入射光学手段はコリメーターレンズを
有し、該コリメーターレンズの近傍に副走査方向の光束
幅を規制する開口絞りを配置したことを特徴としてい
る。According to a thirteenth aspect, in the eighth aspect, the at least one aperture stop regulates a light beam width in the main scanning direction, the incident optical means has a collimator lens, and An aperture stop that regulates the light beam width in the sub-scanning direction is arranged in the vicinity.
【００３１】[0031]
【発明の実施の形態】［実施形態１］図１は本発明の実
施形態１の走査光学装置（マルチビーム走査光学装置）
をレーザービームプリンタやディジタル複写機等の画像
形成装置に適用したときの要部概略図、図２は図１の主
走査方向の要部断面図（主走査断面図）である。FIG. 1 is a scanning optical device (multi-beam scanning optical device) according to a first embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view (main scanning cross-sectional view) of a main part in the main scanning direction of FIG.
【００３２】図１、図２において１は光源手段であり、
例えば複数の発光部（発光点）を有するマルチ半導体レ
ーザーより成っている。２はコリメーターレンズであ
り、光源手段１から出射された複数の発散光束を略平行
光束に変換している。３はシリンドリカルレンズ（シリ
ンダーレンズ）であり、副走査方向にのみ所定の屈折力
を有しており、コリメーターレンズ２で略平行光束に変
換された光束を副走査断面内で後述する光偏向器５の偏
向面（反射面）５ａにほぼ線像として結像させている。1 and 2, reference numeral 1 denotes a light source means,
For example, it is composed of a multi-semiconductor laser having a plurality of light emitting portions (light emitting points). Reference numeral 2 denotes a collimator lens, which converts a plurality of divergent light beams emitted from the light source means 1 into substantially parallel light beams. Reference numeral 3 denotes a cylindrical lens (cylinder lens) having a predetermined refractive power only in the sub-scanning direction, and an optical deflector, which will be described later in the sub-scan section, converts a light beam converted into a substantially parallel light beam by the collimator lens 2. An image is formed as a substantially linear image on the deflecting surface (reflection surface) 5a.
【００３３】４は開口絞りであり、シリンドリカルレン
ズ３と光偏向器５との間の光路内に配されており、シリ
ンドリカルレンズ３から射出した光束を所望の最適なビ
ーム形状に整形している。本実施形態における開口絞り
４の開口部４ａは楕円形状より形成されており、主走査
方向と副走査方向の双方の光束幅を規制しており、また
後述する被走査面としての感光ドラム面７上におけるス
ポット形状が所望の大きさになるように形成されてい
る。Reference numeral 4 denotes an aperture stop, which is disposed in an optical path between the cylindrical lens 3 and the optical deflector 5, and shapes a light beam emitted from the cylindrical lens 3 into a desired optimum beam shape. The opening 4a of the aperture stop 4 in this embodiment is formed in an elliptical shape, regulates the light beam width in both the main scanning direction and the sub-scanning direction, and has a photosensitive drum surface 7 as a surface to be described later. The spot shape on the top is formed so as to have a desired size.
【００３４】尚、マルチ半導体レーザー１、コリメータ
ーレンズ２、そしてシリンドリカルレンズ３等の各要素
は入射光学手段１１の一要素を構成している。Each element such as the multi-semiconductor laser 1, the collimator lens 2, and the cylindrical lens 3 constitutes one element of the incident optical means 11.
【００３５】５は偏向手段としての例えばポリゴンミラ
ー（回転多面鏡）より成る光偏向器であり、モーター等
の駆動手段（不図示）により図中矢印Ａ方向に一定速度
で回転している。Reference numeral 5 denotes an optical deflector comprising, for example, a polygon mirror (rotating polygon mirror) as a deflecting means, which is rotated at a constant speed in a direction indicated by an arrow A in the figure by a driving means (not shown) such as a motor.
【００３６】６はｆθ特性を有する走査光学手段（ｆθ
レンズ系）であり、第１、第２の２枚のｆθレンズ６
ａ，６ｂを有しており、光偏向器５で偏向された複数の
光束を被走査面７上に結像させると共に副走査断面内に
おいて光偏向器５の偏向面５ａと被走査面７との間を略
共役関係にすることにより、該偏向面５ａの倒れを補正
している。Numeral 6 denotes scanning optical means (fθ) having fθ characteristics.
Lens system), and the first and second two fθ lenses 6
a, 6b, the plurality of light beams deflected by the optical deflector 5 are imaged on the surface 7 to be scanned, and the deflecting surface 5a of the optical deflector 5 and the surface 7 The inclination of the deflecting surface 5a is corrected by making a substantially conjugate relationship between.
【００３７】７は被走査面としての感光ドラム面であ
る。Reference numeral 7 denotes a photosensitive drum surface as a surface to be scanned.
【００３８】９は同期検知用ミラー（以下「ＢＤミラ
ー」とも称す。）であり、感光ドラム面７上の走査開始
位置のタイミングを調整する為の同期検知用の光束（以
下「ＢＤ光束」とも称す。）８を後述する同期検知手段
１０側へ反射させている。本実施形態では光偏向器５に
よる偏向直後のＢＤ光束８を走査光学手段６の光軸Ｌに
対し入射光学手段１１側とは反対側の領域を通過するよ
うに設定しており、かつ走査画角の１／２より大きい範
囲を通過するように設定している。Reference numeral 9 denotes a synchronization detection mirror (hereinafter, also referred to as a “BD mirror”), which is a synchronization detection light beam (hereinafter, also referred to as a “BD light beam”) for adjusting the timing of a scanning start position on the photosensitive drum surface 7. 8) is reflected toward the synchronization detecting means 10 described later. In the present embodiment, the BD light beam 8 immediately after being deflected by the light deflector 5 is set so as to pass through a region on the opposite side of the optical axis L of the scanning optical unit 6 from the incident optical unit 11 side, and It is set so as to pass through a range larger than 1/2 of the angle.
【００３９】１０は同期検知手段としての光センサー
（以下「ＢＤセンサー」とも称す。）であり、本実施形
態ではＢＤセンサー１０からの出力信号を検知して得ら
れた同期信号（以下「ＢＤ信号」とも称す。）を用いて
感光ドラム面７上への画像記録の走査開始位置のタイミ
ングを調整している。Reference numeral 10 denotes an optical sensor (hereinafter, also referred to as a “BD sensor”) as a synchronization detecting means. In this embodiment, a synchronization signal (hereinafter, referred to as a “BD signal”) obtained by detecting an output signal from the BD sensor 10 is provided. The timing of the scanning start position of the image recording on the photosensitive drum surface 7 is adjusted.
【００４０】本実施形態においてマルチ半導体レーザー
１から出射した複数の発散光束はコリメーターレンズ２
によって略平行光束に変換され、シリンドリカルレンズ
３に入射している。シリンドリカルレンズ３に入射した
複数の略平行光束のうち主走査断面内においてはそのま
まの状態で射出し、開口絞り４により所望のビーム形状
に整形される。また副走査断面内においては収束して開
口絞り４により所望のビーム形状に整形され、光偏向器
５の偏向面５ａにほぼ線像（主走査方向に長手の線像）
として結像している。そして光偏向器５の偏向面５ａで
偏向された複数の光束は走査光学手段６を介して感光ド
ラム面７上に導光され、該光偏向器５を矢印Ａ方向に回
転させることによって、該感光ドラム面７上を矢印Ｂ方
向（主走査方向）に同時に光走査している。これにより
記録媒体としての感光ドラム面７上に画像記録を行なっ
ている。In this embodiment, a plurality of divergent light beams emitted from the multi-semiconductor laser 1 are
Is converted into a substantially parallel light beam, and is incident on the cylindrical lens 3. Of the plurality of substantially parallel light beams incident on the cylindrical lens 3, they are emitted as they are in the main scanning section and are shaped into a desired beam shape by the aperture stop 4. Further, in the sub-scan section, the beam converges and is shaped into a desired beam shape by the aperture stop 4, and is substantially a line image on the deflection surface 5a of the optical deflector 5 (a line image elongated in the main scanning direction).
As an image. The plurality of light beams deflected by the deflecting surface 5a of the light deflector 5 are guided to the photosensitive drum surface 7 via the scanning optical means 6, and the light deflector 5 is rotated in the direction of arrow A to thereby generate the light. Optical scanning is simultaneously performed on the photosensitive drum surface 7 in the direction of arrow B (main scanning direction). Thus, an image is recorded on the photosensitive drum surface 7 as a recording medium.
【００４１】このとき感光ドラム面７上を光走査する前
に該感光ドラム面７上の走査開始位置のタイミングを調
整する為に光偏向器５で偏向された光束の一部であるＢ
Ｄ光束８をＢＤミラー９で反射させてＢＤセンサー１０
に導光している。そしてＢＤセンサー１０からの出力信
号を検知して得られたＢＤ信号を用いて感光ドラム面７
上への画像記録の走査開始位置のタイミングを調整して
いる。At this time, B is a part of a light beam deflected by the optical deflector 5 in order to adjust the timing of the scanning start position on the photosensitive drum surface 7 before optical scanning on the photosensitive drum surface 7.
The D light beam 8 is reflected by the BD mirror 9 to make the BD sensor 10
The light is guided. Then, using the BD signal obtained by detecting the output signal from the BD sensor 10, the photosensitive drum surface 7 is used.
The timing of the scanning start position for image recording on the upper side is adjusted.
【００４２】尚、図１、図２においては１本のみの光束
を記してある。In FIGS. 1 and 2, only one light beam is shown.
【００４３】本実施形態では入射光学手段１１を構成す
るマルチビーム半導体レーザー１からシリンドリカルレ
ンズ３までの光学素子のうち、光偏向器５に最も近い
（最下流側にある）光学素子であるシリンドリカルレン
ズ３と光偏向器５との間の光路内に光束幅を規制する開
口絞り４を配置している。この開口絞り４を光偏向器５
近傍に配置することにより、該開口絞り４を射出する複
数光束の射出角差が微小に抑えることができる。これに
より走査光学手段６に入射する複数光束の入射位置、入
射角の差も小さくなり、最終的に感光ドラム面７上にお
ける複数光束による走査線の間隔誤差を微小にすること
ができる。In the present embodiment, of the optical elements from the multi-beam semiconductor laser 1 to the cylindrical lens 3 constituting the incident optical means 11, the cylindrical lens which is the optical element closest to the optical deflector 5 (at the most downstream side). An aperture stop 4 for regulating the light flux width is disposed in an optical path between the light deflector 3 and the light deflector 5. This aperture stop 4 is connected to an optical deflector 5
By arranging them in the vicinity, the difference between the emission angles of a plurality of light beams emitted from the aperture stop 4 can be suppressed to a very small value. As a result, the difference between the incident positions and the incident angles of the plurality of light beams incident on the scanning optical means 6 is also reduced, and finally, the scanning line interval error due to the plurality of light beams on the photosensitive drum surface 7 can be reduced.
【００４４】ここで光偏向器５による偏向直後のＢＤ光
束８は上述の如く走査光学手段６の光軸Ｌに対し、入射
光学手段１１とは反対側の領域を通過するように構成
し、かつ走査画角の１／２より大きい範囲を通過するよ
うに設定している。この構成によりＢＤ光束８が開口絞
り４に蹴られることが無く十分なＢＤ光束８がＢＤセン
サー１０に到達することができ、これにより高精度なＢ
Ｄ信号を得ることができる。Here, the BD light beam 8 immediately after being deflected by the light deflector 5 is configured to pass through the area on the opposite side of the optical axis L of the scanning optical means 6 from the incident optical means 11 as described above, and It is set so as to pass through a range larger than 1/2 of the scanning field angle. With this configuration, the BD light beam 8 can reach the BD sensor 10 without the BD light beam 8 being kicked by the aperture stop 4, thereby providing a highly accurate B light beam.
D signal can be obtained.
【００４５】本実施形態では走査光学手段６の光軸Ｌと
入射光学手段１１の光軸Ｍとの成す角をα、該走査光学
手段６の光軸Ｌと光偏向器５による偏向直後のＢＤ光束
８との成す角をβとしたとき、 −β＜α‥‥‥‥（１） （角度の符号は、走査光学手段６の光軸Ｌに対し入射光
学手段１１側に測った角度を＋とする。）なる条件を満
足するように各要素を設定してる。In this embodiment, the angle between the optical axis L of the scanning optical means 6 and the optical axis M of the incident optical means 11 is α, and the optical axis L of the scanning optical means 6 and the BD just after being deflected by the optical deflector 5. Assuming that the angle formed by the light beam 8 is β, −β <α ‥‥‥‥ (1) (The sign of the angle is the angle measured on the side of the incident optical unit 11 with respect to the optical axis L of the scanning optical unit 6 by + Each element is set so as to satisfy the following condition.
【００４６】尚、本実施形態において更に好ましくは条
件式（１）を次の如く設定するのが良い。In this embodiment, it is more preferable to set the conditional expression (1) as follows.
【００４７】−β＜α≦９０° ‥‥‥‥（２） 上記条件式（１），（２）を逸脱すると入射光学手段１
１を射出したＢＤ光束８の一部が偏向面５ａ上で蹴ら
れ、十分なＢＤ光束８がＢＤセンサー１０に導光され
ず、この結果、ＢＤ信号が鈍ったり、広範囲な配置スペ
ースを確保する必要が生じ、装置全体の大型化を招くの
で良くない。-Β <α ≦ 90 ° (2) If the above conditional expressions (1) and (2) are deviated, the incident optical means 1
Part of the BD light beam 8 that has emitted 1 is kicked on the deflecting surface 5a, and a sufficient amount of the BD light beam 8 is not guided to the BD sensor 10. As a result, the BD signal becomes dull or a wide space is secured. This is not desirable because the necessity arises and the size of the entire apparatus is increased.
【００４８】このように本実施形態では上述の如く開口
絞り４を光偏向器５近傍に配置した場合でも、ＢＤ光束
８が該開口絞り４に蹴られることなく、高精細な印字が
可能なコンパクトな走査光学装置を得ている。As described above, in the present embodiment, even when the aperture stop 4 is arranged near the optical deflector 5 as described above, the BD light beam 8 is not kicked by the aperture stop 4 and a compact print capable of high-definition printing is possible. Scanning optical device.
【００４９】［実施形態２］図３は本発明の実施形態２
の走査光学装置をレーザービームプリンタやディジタル
複写機等の画像形成装置に適用したときの要部概略図、
図４は図３の主走査方向の要部断面図（主走査断面図）
である。図３、図４において図１、図２に示した要素と
同一要素には同符番を付している。[Embodiment 2] FIG. 3 shows Embodiment 2 of the present invention.
Main part schematic diagram when the scanning optical device is applied to an image forming apparatus such as a laser beam printer or a digital copying machine,
FIG. 4 is a cross-sectional view of main parts in the main scanning direction in FIG. 3 (main scanning cross-sectional view).
It is. 3 and 4, the same elements as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.
【００５０】本実施形態において前述の実施形態１と異
なる点は光偏向器５近傍に配置する開口絞り４１を主走
査方向のみの光束幅を規制するスリットから構成し、副
走査方向の光束幅はコリメーターレンズ２近傍に配置し
た開口絞り４２によって規制したことである。その他の
構成及び光学的作用は実施形態１と略同様であり、これ
により同様な効果を得ている。In this embodiment, the difference from the first embodiment is that the aperture stop 41 arranged near the optical deflector 5 is constituted by a slit for regulating the light beam width only in the main scanning direction, and the light beam width in the sub-scanning direction is That is, it is restricted by the aperture stop 42 arranged near the collimator lens 2. Other configurations and optical functions are substantially the same as those of the first embodiment, and thus, similar effects are obtained.
【００５１】即ち、同図において４１は光偏向器５近傍
に配置された開口絞りであり、主走査方向の光束幅を規
制するスリットから成っている。４２はコリメーターレ
ンズ近傍に配置された開口絞りであり、副走査方向の光
束幅を規制している。That is, in the figure, reference numeral 41 denotes an aperture stop arranged near the optical deflector 5, which is constituted by a slit for regulating the light flux width in the main scanning direction. Reference numeral 42 denotes an aperture stop arranged near the collimator lens, which regulates the light beam width in the sub-scanning direction.
【００５２】本実施形態では上記の各開口絞り４１，４
２を各々入射光学手段１１内に配置することにより、組
立て時におけるシリンドリカルレンズ３の固定位置調整
が容易になり、また光偏向器５近傍のスリット４１を光
学箱に一体的に成形することが可能となる。In this embodiment, each of the aperture stops 41 and 4 described above is used.
By arranging the lenses 2 in the incident optical means 11, it is easy to adjust the fixed position of the cylindrical lens 3 during assembly, and the slit 41 near the optical deflector 5 can be integrally formed with the optical box. Becomes
【００５３】このように本実施形態では前述の実施形態
１と同様に開口絞り４１を光偏向器５近傍に配置した場
合でも、ＢＤ光束８が該開口絞り４１に蹴られることな
く、高精細な印字が可能なコンパクトな走査光学装置を
得ている。As described above, in the present embodiment, even when the aperture stop 41 is disposed near the optical deflector 5 as in the first embodiment, the BD light beam 8 is not kicked by the aperture stop 41 and high definition. A compact scanning optical device capable of printing has been obtained.
【００５４】［実施形態３］図５は本発明の実施形態３
の走査光学装置をレーザービームプリンタやディジタル
複写機等の画像形成装置に適用したときの要部概略図、
図６は図５の主走査方向の要部断面図（主走査断面図）
である。図５、図６において図１、図２に示した要素と
同一要素には同符番を付している。[Embodiment 3] FIG. 5 shows Embodiment 3 of the present invention.
Main part schematic diagram when the scanning optical device is applied to an image forming apparatus such as a laser beam printer or a digital copying machine,
FIG. 6 is a sectional view of a main part in the main scanning direction of FIG. 5 (main scanning sectional view).
It is. 5 and 6, the same elements as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.
【００５５】本実施形態において前述の実施形態１と異
なる点は光偏向器５による偏向直後のＢＤ光束８を入射
光学手段１１の光軸Ｍに対し走査光学手段６とは反対側
の領域を通過するように構成したことである。その他の
構成及び光学的作用は実施形態１と略同様であり、これ
により同様な効果を得ている。This embodiment differs from the first embodiment in that the BD beam 8 immediately after being deflected by the optical deflector 5 passes through the area opposite to the scanning optical unit 6 with respect to the optical axis M of the incident optical unit 11. That is to say, Other configurations and optical functions are substantially the same as those of the first embodiment, and thus, similar effects are obtained.
【００５６】即ち、本実施形態では走査光学手段６の光
軸Ｌと入射光学手段１１の光軸Ｍとの成す角をα、該走
査光学手段１１の光軸Ｌと光偏向器５による偏向直後の
ＢＤ光束８との成す角をβとしたとき、 α＜β ‥‥‥‥（３） （角度の符号は、走査光学手段６の光軸Ｌに対し入射光
学手段１１側に測った角度を＋とする。）なる条件を満
足するように各要素を設定している。That is, in this embodiment, the angle between the optical axis L of the scanning optical means 6 and the optical axis M of the incident optical means 11 is α, and the angle between the optical axis L of the scanning optical means 11 and the optical deflector 5 immediately after deflection. Where β is the angle formed by the BD light beam 8, α <β ‥‥‥‥ (3) (The sign of the angle is the angle measured on the side of the incident optical unit 11 with respect to the optical axis L of the scanning optical unit 6. Each element is set so as to satisfy the following condition.
【００５７】尚、本実施形態において更に好ましくは条
件式（３）を次の如く設定するのが良い。In this embodiment, it is more preferable to set the conditional expression (3) as follows.
【００５８】０．５β＜α＜β ‥‥‥‥（４） 条件式（３），（４）を逸脱すると光偏向器５によって
偏向されたＢＤ光束８の一部が、該光偏向器５近傍に配
置された開口絞り４により蹴られたり、入射光学手段１
１を構成する光学素子に干渉することにより十分なＢＤ
光束８がＢＤセンサー１０に導光されず、この結果、Ｂ
Ｄ信号が鈍る等の弊害が生じるので良くない。0.5β <α <β ‥‥‥‥ (4) If conditional expressions (3) and (4) are deviated, a part of the BD light beam 8 deflected by the optical deflector 5 It is kicked by the aperture stop 4 arranged in the vicinity, or the incident optical means 1
Sufficient BD by interfering with the optical element constituting
The light beam 8 is not guided to the BD sensor 10, and as a result,
It is not good because adverse effects such as dulling of the D signal occur.
【００５９】また本実施形態ではＢＤ光束８を集束させ
てＢＤセンサー１０に入射させるための集束レンズ１２
を配置している。これにより装置全体の小型化を図って
いる。In this embodiment, a focusing lens 12 for focusing the BD light beam 8 and making it incident on the BD sensor 10.
Has been arranged. Thereby, the size of the entire apparatus is reduced.
【００６０】このように本実施形態では前述の実施形態
１と同様に開口絞り４を光偏向器５近傍に配置した場合
でも、ＢＤ光束８が該開口絞り４に蹴られることなく、
高精細な印字が可能なコンパクトな走査光学装置を得て
いる。As described above, in the present embodiment, even when the aperture stop 4 is disposed near the optical deflector 5 as in the first embodiment, the BD light beam 8 is not kicked by the aperture stop 4,
A compact scanning optical device capable of high-definition printing has been obtained.
【００６１】［実施形態４］図７は本発明の実施形態４
の走査光学装置をレーザービームプリンタやディジタル
複写機等の画像形成装置に適用したときの要部概略図、
図８は図７の主走査方向の要部断面図（主走査断面図）
である。図７、図８において図５、図６に示した要素と
同一要素には同符番を付している。[Fourth Embodiment] FIG. 7 shows a fourth embodiment of the present invention.
Main part schematic diagram when the scanning optical device is applied to an image forming apparatus such as a laser beam printer or a digital copying machine,
FIG. 8 is a sectional view of a main part in the main scanning direction of FIG. 7 (main scanning sectional view).
It is. 7 and 8, the same elements as those shown in FIGS. 5 and 6 are denoted by the same reference numerals.
【００６２】本実施形態において前述の実施形態３と異
なる点は光偏向器５近傍に配置する開口絞り４１を主走
査方向のみの光束幅を規制するスリットから構成し、副
走査方向の光束幅はコリメーターレンズ２近傍に配置し
た開口絞り４２によって規制したことである。その他の
構成及び光学的作用は実施形態３と略同様であり、これ
により同様な効果を得ている。The present embodiment differs from the third embodiment in that the aperture stop 41 disposed near the optical deflector 5 is constituted by a slit for regulating the light beam width only in the main scanning direction. That is, it is restricted by the aperture stop 42 arranged near the collimator lens 2. Other configurations and optical functions are substantially the same as those of the third embodiment, and thus, similar effects are obtained.
【００６３】即ち、同図において４１は光偏向器５近傍
に配置された開口絞りであり、主走査方向の光束幅を規
制するスリットから成っている。４２はコリメーターレ
ンズ２近傍に配置された開口絞りであり、副走査方向の
光束幅を規制している。That is, in the figure, reference numeral 41 denotes an aperture stop arranged in the vicinity of the light deflector 5 and is constituted by a slit for regulating the light flux width in the main scanning direction. Reference numeral 42 denotes an aperture stop arranged near the collimator lens 2, which regulates the light beam width in the sub-scanning direction.
【００６４】本実施形態では上記の各開口絞り４１，４
２を各々入射光学手段１１内に配置することにより、組
立て時におけるシリンドリカルレンズ３の固定位置調整
が容易になり、また光偏向器５近傍のスリット４１を光
学箱に一体的に成形することが可能となる。In this embodiment, each of the aperture stops 41 and 4 described above is used.
By arranging the lenses 2 in the incident optical means 11, the fixing position of the cylindrical lens 3 can be easily adjusted at the time of assembly, and the slit 41 near the optical deflector 5 can be integrally formed with the optical box. Becomes
【００６５】このように本実施形態では前述の実施形態
３と同様に開口絞り４１を光偏向器５近傍に配置した場
合でも、ＢＤ光束８が該開口絞り４１に蹴られることな
く、高精細な印字が可能なコンパクトな走査光学装置を
得ている。As described above, in the present embodiment, even when the aperture stop 41 is disposed near the optical deflector 5 as in the above-described third embodiment, the BD light beam 8 is not kicked by the aperture stop 41 and high definition is achieved. A compact scanning optical device capable of printing has been obtained.
【００６６】尚、各実施形態では複数の光束で被走査面
上を同時に光走査するマルチビーム走査光学装置につい
て述べたが、もちろん単一の光束で被走査面上を光走査
する走査光学装置においても適用できることは言うまで
もない。In each of the embodiments, the multi-beam scanning optical device for simultaneously scanning the surface to be scanned with a plurality of light beams has been described. Needless to say, this can also be applied.
【００６７】[0067]
【発明の効果】本発明によれば前述の如く、 入射光学手段を構成する複数の光学素子のうち、最下
流側にある光学素子と偏向手段との間に光束幅を規制す
る少なくとも１つの開口絞りを配置し、偏向手段による
偏向直後の同期検知用の光束が走査光学手段の光軸に対
し入射光学手段とは反対側の領域を通過するように構成
する、もしくは 入射光学手段を構成する複数の光学素子のうち、最下
流側にある光学素子と偏向手段との間に光束幅を規制す
る少なくとも１つの開口絞りを配置し、偏向手段による
偏向直後の同期検知用の光束が入射光学手段の光軸に対
し走査光学手段とは反対側の領域を通過するように構成
する、ことにより、開口絞りを偏向手段近傍に配置した
場合でも、同期検知用の光束が該開口絞りに蹴られるこ
となく十分確保することができ、高精細な印字が可能な
コンパクトな走査光学装置を達成することができる。According to the present invention, as described above, at least one aperture for regulating the light beam width between the most downstream optical element and the deflecting means among the plurality of optical elements constituting the incident optical means. A diaphragm is arranged, and a light beam for synchronization detection immediately after deflection by the deflection means is configured to pass through a region on the opposite side of the optical axis of the scanning optical means from the incident optical means, or a plurality of light beams constituting the incident optical means. At least one aperture stop that regulates the light flux width is disposed between the optical element on the most downstream side and the deflecting means, and the light flux for synchronization detection immediately after deflection by the deflecting means is incident on the incident optical means. By configuring so as to pass through the area opposite to the scanning optical means with respect to the optical axis, even when the aperture stop is arranged near the deflecting means, the light beam for synchronization detection is not kicked by the aperture stop. Secure enough Rukoto can, it is possible to achieve a compact optical scanning apparatus capable of high-definition printing.
【図１】 本発明の実施形態１の要部概略図FIG. 1 is a schematic view of a main part of a first embodiment of the present invention.
【図２】 図１の主走査方向の要部断面図FIG. 2 is a sectional view of a main part in a main scanning direction of FIG. 1;
【図３】 本発明の実施形態２の要部概略図FIG. 3 is a schematic diagram of a main part of a second embodiment of the present invention.
【図４】 図３の主走査方向の要部断面図FIG. 4 is a sectional view of a main part in the main scanning direction of FIG. 3;
【図５】 本発明の実施形態３の要部概略図FIG. 5 is a schematic view of a main part of a third embodiment of the present invention.
【図６】 図５の主走査方向の要部断面図FIG. 6 is a sectional view of a main part in the main scanning direction of FIG. 5;
【図７】 本発明の実施形態４の要部概略図FIG. 7 is a schematic diagram of a main part of a fourth embodiment of the present invention.
【図８】 図７の主走査方向の要部断面図8 is a sectional view of a main part in the main scanning direction of FIG. 7;
【図９】 従来の走査光学装置の主走査方向の要部断面
図FIG. 9 is a sectional view of a main part of a conventional scanning optical device in a main scanning direction.
１ 光源手段（マルチビーム半導体レーザー） ２ コリメーターレンズ ４、４１、４２ 開口絞り ３ シリンドリカルレンズ ５ 偏向手段（回転多面鏡） ５ａ 偏向面 ６ 走査光学手段 ６ａ 第１のｆθレンズ ６ｂ 第２のｆθレンズ ７ 被走査面（感光ドラム面） ８ 同期検知用の光束 ９ 同期検知用ミラー １０ 同期検知用センサー １１ 入射光学手段 １２ 集束レンズ Reference Signs List 1 light source means (multi-beam semiconductor laser) 2 collimator lens 4, 41, 42 aperture stop 3 cylindrical lens 5 deflecting means (rotating polygon mirror) 5a deflecting surface 6 scanning optical means 6a first fθ lens 6b second fθ lens 7 Scanned surface (photosensitive drum surface) 8 Light flux for synchronization detection 9 Mirror for synchronization detection 10 Sensor for synchronization detection 11 Incident optical means 12 Converging lens
Claims (13)
した複数の光束を主走査方向に長い線状の光束として結
像させる入射光学手段と、 該入射光学手段の結像位置近傍に偏向面を有し、入射さ
れた複数の光束を主走査方向に偏向走査する偏向手段
と、 該偏向手段で偏向された複数の光束を被走査面上に結像
させる走査光学手段と、 該偏向手段で偏向された光束の一部である同期検知用の
光束を用いて該被走査面上の走査開始位置のタイミング
を制御する同期検知手段と、 を有する走査光学装置において、 該入射光学手段を構成する複数の光学素子のうち、最も
偏向手段側にある光学素子と該偏向手段との間の光路内
に少なくとも１つの開口絞りを配置しており、該偏向手
段による偏向直後の該同期検知用の光束は該走査光学手
段の光軸に対し、該入射光学手段側とは反対側の領域を
通過する光束の一部を用いたことを特徴とする走査光学
装置。1. An incidence optical means for forming an image of a plurality of light beams emitted from a light source means having a plurality of light emitting portions as a long linear light beam in a main scanning direction, and a deflecting surface near an imaging position of the incident optical means. A deflecting unit for deflecting and scanning the plurality of incident light beams in the main scanning direction; a scanning optical unit for forming an image of the plurality of light beams deflected by the deflecting unit on a surface to be scanned; A scanning detection device for controlling the timing of a scanning start position on the surface to be scanned by using a light beam for synchronization detection, which is a part of the deflected light beam. Among the plurality of optical elements, at least one aperture stop is arranged in an optical path between the optical element closest to the deflecting means and the deflecting means, and the light beam for synchronization detection immediately after deflection by the deflecting means. Is the optical axis of the scanning optical means. And, scanning optical apparatus characterized by using a part of the light beam passing through the area opposite the said incident optical means side.
手段の光軸との成す角をα、該走査光学手段の光軸と該
偏向手段による偏向直後の同期検知用の光束との成す角
をβとしたとき、 −β＜α （角度の符号は走査光学手段の光軸に対し入射光学手段
側に測った角度を＋とする。）なる条件を満足すること
を特徴とする請求項１記載の走査光学装置。2. The angle between the optical axis of the scanning optical means and the optical axis of the incident optical means is α, and the optical axis of the scanning optical means and the light beam for synchronization detection immediately after deflection by the deflection means are formed. The angle satisfies the condition of -β <α (the sign of the angle is +, the angle measured on the incident optical means side with respect to the optical axis of the scanning optical means). 2. The scanning optical device according to 1.
手段の光軸との成す角をα、該走査光学手段の光軸と該
偏向手段による偏向直後の同期検知用の光束との成す角
をβとしたとき、 −β＜α≦９０° （角度の符号は走査光学手段の光軸に対し入射光学手段
側に測った角度を＋とする。）なる条件を満足すること
を特徴とする請求項１記載の走査光学装置。3. The angle between the optical axis of the scanning optical means and the optical axis of the incident optical means is α, and the optical axis of the scanning optical means and the light beam for synchronization detection immediately after deflection by the deflection means are formed. When the angle is β, the following condition is satisfied: −β <α ≦ 90 ° (the sign of the angle is defined as + with respect to the optical axis of the scanning optical means on the side of the incident optical means). The scanning optical device according to claim 1.
画角の１／２より大きい範囲を通過することを特徴とす
る請求項１記載の走査光学装置。4. The scanning optical apparatus according to claim 1, wherein the light beam for synchronization detection immediately after the deflection passes through a range larger than 走 査 of a scanning angle of view.
方向と副走査方向の双方の光束幅を規制していることを
特徴とする請求項１記載の走査光学装置。5. The scanning optical apparatus according to claim 1, wherein said at least one aperture stop regulates a light beam width in both a main scanning direction and a sub-scanning direction.
方向の光束幅を規制していることを特徴とする請求項１
記載の走査光学装置。6. The apparatus according to claim 1, wherein the at least one aperture stop regulates a light beam width in a main scanning direction.
The scanning optical device according to claim 1.
方向の光束幅を規制し、前記入射光学手段はコリメータ
ーレンズを有し、該コリメーターレンズの近傍に副走査
方向の光束幅を規制する開口絞りを配置したことを特徴
とする請求項１記載の走査光学装置。7. The at least one aperture stop regulates a light beam width in a main scanning direction, the incident optical means has a collimator lens, and regulates a light beam width in a sub-scanning direction near the collimator lens. 2. The scanning optical device according to claim 1, wherein an aperture stop is arranged.
した複数の光束を主走査方向に長い線状の光束として結
像させる入射光学手段と、 該入射光学手段の結像位置近傍に偏向面を有し、入射さ
れた複数の光束を主走査方向に偏向走査する偏向手段
と、 該偏向手段で偏向された複数の光束を被走査面上に結像
させる走査光学手段と、 該偏向手段で偏向された光束の一部である同期検知用の
光束を用いて該被走査面上の走査開始位置のタイミング
を制御する同期検知手段と、 を有する走査光学装置において、 該入射光学手段を構成する複数の光学素子のうち、最も
偏向手段側にある光学素子と該偏向手段との間の光路内
に少なくとも１つの開口絞りを配置しており、該偏向手
段による偏向直後の該同期検知用の光束は該入射光学手
段の光軸に対し該走査光学手段側とは反対側の領域を通
過する光束の一部を用いたことを特徴とする走査光学装
置。8. An incident optical means for forming an image of a plurality of light beams emitted from a light source means having a plurality of light emitting portions as a long linear light beam in the main scanning direction, and a deflecting surface near an image forming position of the incident optical means. A deflecting unit for deflecting and scanning the plurality of incident light beams in the main scanning direction; a scanning optical unit for forming an image of the plurality of light beams deflected by the deflecting unit on a surface to be scanned; A scanning detection device for controlling the timing of a scanning start position on the surface to be scanned by using a light beam for synchronization detection, which is a part of the deflected light beam. Among the plurality of optical elements, at least one aperture stop is arranged in an optical path between the optical element closest to the deflecting means and the deflecting means, and the light flux for synchronization detection immediately after deflection by the deflecting means. Is on the optical axis of the incident optical means. Scanning optical apparatus characterized by using a part of the light beam passing through the area opposite the said scanning optical means side.
手段の光軸との成す角をα、該走査光学手段の光軸と該
偏向手段による偏向直後の同期検知用の光束との成す角
をβとしたとき、 α＜β （角度の符号は走査光学手段の光軸に対し入射光学手段
側に測った角度を＋とする。）なる条件を満足すること
を特徴とする請求項８記載の走査光学装置。9. An angle α between the optical axis of the scanning optical means and the optical axis of the incident optical means, and an optical axis of the scanning optical means and a light beam for synchronization detection immediately after deflection by the deflection means. 9. The condition of α <β (where the sign of the angle is + with respect to the optical axis of the scanning optical means and the angle measured on the incident optical means side) when the angle is β. The scanning optical device according to claim 1.
学手段の光軸との成す角をα、該走査光学手段の光軸と
該偏向手段による偏向直後の同期検知用の光束との成す
角をβとしたとき、 ０．５β＜α＜β （角度の符号は走査光学手段の光軸に対し入射光学手段
側に測った角度を＋とする。）なる条件を満足すること
を特徴とする請求項８記載の走査光学装置。10. An angle between the optical axis of the scanning optical unit and the optical axis of the incident optical unit is α, and the optical axis of the scanning optical unit and a light beam for synchronization detection immediately after deflection by the deflection unit are formed. When the angle is β, the following condition is satisfied: 0.5β <α <β (the sign of the angle is + with respect to the optical axis of the scanning optical means to the incident optical means side). The scanning optical device according to claim 8, wherein
査方向と副走査方向の双方の光束幅を規制していること
を特徴とする請求項８記載の走査光学装置。11. The scanning optical apparatus according to claim 8, wherein said at least one aperture stop regulates a light beam width in both a main scanning direction and a sub-scanning direction.
査方向の光束幅を規制していることを特徴とする請求項
８記載の走査光学装置。12. The scanning optical device according to claim 8, wherein the at least one aperture stop regulates a light beam width in a main scanning direction.
査方向の光束幅を規制し、前記入射光学手段はコリメー
ターレンズを有し、該コリメーターレンズの近傍に副走
査方向の光束幅を規制する開口絞りを配置したことを特
徴とする請求項８記載の走査光学装置。13. The at least one aperture stop regulates the light beam width in the main scanning direction, the incident optical means has a collimator lens, and regulates the light beam width in the sub-scanning direction near the collimator lens. 9. The scanning optical device according to claim 8, further comprising an aperture stop.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18915499A JP4365939B2 (en) | 1999-07-02 | 1999-07-02 | Scanning optical device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18915499A JP4365939B2 (en) | 1999-07-02 | 1999-07-02 | Scanning optical device |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| JP2001021819A true JP2001021819A (en) | 2001-01-26 |
| JP2001021819A5 JP2001021819A5 (en) | 2006-08-10 |
| JP4365939B2 JP4365939B2 (en) | 2009-11-18 |
Family
ID=16236353
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18915499A Expired - Fee Related JP4365939B2 (en) | 1999-07-02 | 1999-07-02 | Scanning optical device |
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| Country | Link |
|---|---|
| JP (1) | JP4365939B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002258186A (en) * | 2001-03-06 | 2002-09-11 | Canon Inc | Light source device |
| JP2010175996A (en) * | 2009-01-30 | 2010-08-12 | Ricoh Co Ltd | Optical scanning apparatus and image forming apparatus |
| JP2014115670A (en) * | 2014-01-22 | 2014-06-26 | Ricoh Co Ltd | Optical scanner and image forming apparatus |
| JP2016186596A (en) * | 2015-03-27 | 2016-10-27 | 京セラドキュメントソリューションズ株式会社 | Optical scanner and image forming apparatus |
| US9864296B2 (en) | 2014-03-17 | 2018-01-09 | Ricoh Company, Ltd. | Optical scanner and image forming device incorporating same |
-
1999
- 1999-07-02 JP JP18915499A patent/JP4365939B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002258186A (en) * | 2001-03-06 | 2002-09-11 | Canon Inc | Light source device |
| JP2010175996A (en) * | 2009-01-30 | 2010-08-12 | Ricoh Co Ltd | Optical scanning apparatus and image forming apparatus |
| JP2014115670A (en) * | 2014-01-22 | 2014-06-26 | Ricoh Co Ltd | Optical scanner and image forming apparatus |
| US9864296B2 (en) | 2014-03-17 | 2018-01-09 | Ricoh Company, Ltd. | Optical scanner and image forming device incorporating same |
| US10409192B2 (en) | 2014-03-17 | 2019-09-10 | Ricoh Company, Ltd. | Optical scanner and image forming device incorporating same |
| JP2016186596A (en) * | 2015-03-27 | 2016-10-27 | 京セラドキュメントソリューションズ株式会社 | Optical scanner and image forming apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4365939B2 (en) | 2009-11-18 |
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