JP2505593B2 - Synchronous signal detection device for optical scanning device - Google Patents
Synchronous signal detection device for optical scanning deviceInfo
- Publication number
- JP2505593B2 JP2505593B2 JP1229549A JP22954989A JP2505593B2 JP 2505593 B2 JP2505593 B2 JP 2505593B2 JP 1229549 A JP1229549 A JP 1229549A JP 22954989 A JP22954989 A JP 22954989A JP 2505593 B2 JP2505593 B2 JP 2505593B2
- Authority
- JP
- Japan
- Prior art keywords
- light beam
- synchronizing signal
- signal detecting
- scanning
- receiving element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Facsimile Scanning Arrangements (AREA)
- Facsimile Transmission Control (AREA)
- Mechanical Optical Scanning Systems (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、レーザプリンタ等に用いられる光走査装置
における同期信号検出装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronizing signal detecting device in an optical scanning device used in a laser printer or the like.
（従来の技術） レーザプリンタ等に用いられる光走査装置では、走査
結像面上の一定の位置から１ラインごとに画像が記録さ
れるようにする必要があり、そのために同期信号検出装
置を設け、この同期信号検出装置によって光ビームを検
出した時点から一定のタイミングにおいて光ビームを画
像信号で変調するようになっている。こうすることによ
って所期の画像を得ることができる。(Prior Art) In an optical scanning device used for a laser printer or the like, it is necessary to record an image line by line from a fixed position on a scanning image forming surface, and a synchronization signal detecting device is provided for that purpose. The light beam is modulated by the image signal at a constant timing from the time when the light beam is detected by the synchronization signal detecting device. By doing so, the desired image can be obtained.
第３図は、例えば、特開昭59−147319号公報に記載さ
れているような、同期信号検出装置を有する従来の光走
査装置の例を示す。第３図において、レーザ発生装置等
でなる光ビーム発生手段11は画像信号で変調された光ビ
ームを発生することができ、この光ビームは、適宜のミ
ラーやコリメートレンズ系やシリンドリカルレンズ等を
介して回転多面鏡12に導かれる。光ビームは回転多面鏡
12の回転駆動によって偏向され、この偏向光ビームは、
ｆθレンズ系を構成する結像レンズ系13を経て走査結像
面である感光体ドラム14の集面上に結像され、かつ、ド
ラム14の周面上を走査する。結像レンズ系13と感光体ド
ラム14との間には、回転多面鏡12による偏向範囲の一方
の側端部において同期信号検出用反射ミラー15が配置さ
れており、このミラー15による光ビームの反射光路上に
は同期信号検出用受光素子16が配置されている。受光素
子16は、回転多面鏡12による偏向範囲の一方の側端部の
光ビームを検出する。この検出信号の出力時点から一定
のタイミングで光ビーム発生手段11において光ビームを
画像信号で変調することにより、感光体ドラム14の所定
の位置から画像信号を記録することができる。こうし
て、光ビームによる主走査と感光体ドラム14の回転によ
る副走査とを繰り返して行うことにより感光体ドラム14
に所期の画像の潜象を形成することができ、これをトナ
ーで現像することによって画像を再現できることは周知
のとおりである。FIG. 3 shows an example of a conventional optical scanning device having a synchronizing signal detecting device as described in, for example, JP-A-59-147319. In FIG. 3, a light beam generating means 11 composed of a laser generator or the like can generate a light beam modulated by an image signal, and this light beam is passed through an appropriate mirror, collimating lens system, cylindrical lens or the like. Is guided to the rotary polygon mirror 12. Light beam is a rotating polygon mirror
The polarized light beam is deflected by the rotation drive of 12
An image is formed on the collecting surface of the photosensitive drum 14 which is a scanning image forming surface through the image forming lens system 13 which constitutes the fθ lens system, and the peripheral surface of the drum 14 is scanned. Between the imaging lens system 13 and the photosensitive drum 14, a synchronization signal detecting reflection mirror 15 is arranged at one side end of the deflection range of the rotary polygon mirror 12, and the mirror 15 detects the light beam of the light beam. A light receiving element 16 for detecting a synchronization signal is arranged on the reflected light path. The light receiving element 16 detects the light beam at one side end of the deflection range of the rotary polygon mirror 12. By modulating the light beam with the image signal in the light beam generating means 11 at a constant timing from the time of outputting the detection signal, the image signal can be recorded from a predetermined position on the photosensitive drum 14. In this way, the main scanning by the light beam and the sub-scanning by the rotation of the photosensitive drum 14 are repeatedly performed so that the photosensitive drum 14
It is well known that a desired image latent image can be formed and the image can be reproduced by developing it with toner.
（発明が解決しようとする課題） 上記のような光走査装置において、光ビームを受光素
子16で受光して同期信号を出力させるには、受光素子16
の受光面上において光ビームを集束させる必要がある。
仮りに受光素子16の受光面上において光ビームを集束さ
せることができないとすれば、受光素子16による検出信
号の立ち上がりが鈍くなり、回転多面鏡12の各反射面の
反射率のばらつきその他の条件によって同期信号の発生
のタイミングがばらつき、再現される画像の質が低下す
るからである。そこで、上記のような光走査装置では、
結像レンズ系13から反射ミラー15までの距離ａと反射ミ
ラー15から受光素子16までの距離ｂとを足した距離が、
結像レンズ系13から感光体ドラム14上の走査結像面まで
の距離Ａと等しくなるように設定している。そのため、
結像レンズ系13から感光体ドラム14までの光路長が長い
場合には反射ミラー15から受光素子16までの光路長も長
くする必要があり、装置が大型化するという問題があ
る。(Problems to be Solved by the Invention) In the optical scanning device as described above, in order to receive a light beam by the light receiving element 16 and output a synchronization signal, the light receiving element 16
It is necessary to focus the light beam on the light receiving surface of.
If the light beam cannot be focused on the light-receiving surface of the light-receiving element 16, the rising of the detection signal by the light-receiving element 16 becomes dull, and variations in the reflectance of each reflecting surface of the rotary polygon mirror 12 and other conditions. This is because the timing of generation of the synchronization signal varies, and the quality of the reproduced image deteriorates. Therefore, in the optical scanning device as described above,
The sum of the distance a from the imaging lens system 13 to the reflecting mirror 15 and the distance b from the reflecting mirror 15 to the light receiving element 16 is
It is set to be equal to the distance A from the image forming lens system 13 to the scanning image forming surface on the photosensitive drum 14. for that reason,
When the optical path length from the imaging lens system 13 to the photosensitive drum 14 is long, the optical path length from the reflection mirror 15 to the light receiving element 16 also needs to be long, which causes a problem that the device becomes large.
かかる問題点を解消するために、同期信号検出用反射
ミラーと受光素子との間に光集束用凸レンズを介在させ
たものもある。特開昭63−173010号公報記載のものはそ
の例である。しかしながら、この例の場合も光集束用の
レンズを新たに付加する必要があるため、装置の小型化
を図るには限度がある。In order to solve such a problem, there is also one in which a convex lens for focusing light is interposed between the reflection mirror for detecting the synchronization signal and the light receiving element. The example described in JP-A-63-173010 is an example. However, in the case of this example as well, since it is necessary to newly add a lens for focusing light, there is a limit to downsizing the device.
本発明は、かかる従来技術の問題点を解消するために
なされたもので、光集束用のレンズを付加しなくても、
同期信号検出用受光素子までの光路長を、走査結像面ま
での光路長と同等に確保することを可能にし、もって、
装置のより小型化を可能にした光走査装置の同期信号検
出装置を提供することを目的とする。The present invention has been made in order to solve the problems of the prior art, and without adding a lens for focusing light,
It is possible to secure the optical path length to the light receiving element for detecting the synchronization signal, which is equal to the optical path length to the scanning image forming surface.
An object of the present invention is to provide a synchronizing signal detecting device for an optical scanning device, which enables further downsizing of the device.
（課題を解決するための手段） 本発明は、結像レンズ系の周辺部を、正のパワーを有
する同期信号検出用光ビーム透過部とし、上記同期信号
検出用光ビーム透過部を透過した光ビームを反射して再
び上記同期信号検出用光ビーム透過部に導く反射ミラー
を設け、この反射ミラーで反射されかつ同期信号検出用
光ビーム透過部を透過した同期信号検出用光ビームを検
出する受光素子を設けたことを特徴とする。(Means for Solving the Problems) According to the present invention, the peripheral portion of the imaging lens system is a synchronizing signal detecting light beam transmitting portion having a positive power, and light transmitted through the synchronizing signal detecting light beam transmitting portion is used. A reflection mirror is provided which reflects the beam and guides it again to the synchronizing signal detecting light beam transmitting section, and receives the synchronizing signal detecting light beam reflected by the reflecting mirror and passing through the synchronizing signal detecting light beam transmitting section. It is characterized in that an element is provided.
（作用） 同期信号検出に用いられる光ビームは、結像レンズ系
の同期信号検出用光ビーム透過部を透過したあと反射ミ
ラーで反射されて再び同期信号検出用光ビーム透過部を
透過し、受光素子に導かれて同期信号検出に供される。
上記同期信号検出用光ビーム透過部は正のパワーをもっ
ているため、光ビームが２回透過することにより、２回
にわたって集束される。(Function) The light beam used for the synchronization signal detection passes through the synchronization signal detection light beam transmission part of the imaging lens system, is then reflected by the reflection mirror, passes through the synchronization signal detection light beam transmission part again, and is received. It is guided to an element and is used for detecting a synchronizing signal.
Since the synchronizing signal detecting light beam transmitting portion has a positive power, the light beam is transmitted twice and thus focused twice.
（実施例） 以下、第１図、第２図を参照しながら本発明にかかる
光走査装置の同期信号検出装置の実施例について説明す
る。(Embodiment) An embodiment of a sync signal detecting device of an optical scanning device according to the present invention will be described below with reference to FIGS. 1 and 2.
第１図、第２図において、半導体レーザ等でなる光ビ
ーム発生手段１は画像信号で変調された光ビームを発生
することができ、この光ビームは、コリメートレンズ２
により平行光束とされたあとシリンドリカルレンズ３を
経て回転多面鏡４に導かれ、回転多面鏡４の回転駆動に
よって偏向される。回転多面鏡４による偏向光ビーム
は、ｆθレンズ系を構成する結像レンズ系を透過し、ま
た、反射ミラー６により略直角に曲げられて感光体ドラ
ム等でなる走査結像面９上に結像され、かつ、走査結像
面９上を走査する。上記結像レンズ系は、ｆθ特性を有
する結像レンズ5aと、走査用補正レンズ5bとからなる。
回転多面鏡４による光ビーム偏向範囲の一方の側端部に
おける光ビームは同期信号検出用光ビームであり、この
同期信号検出用光ビームが透過する走査用補正レンズ5b
の周辺部は、正のパワーを有する同期信号検出用光ビー
ム透過部5b1となっている。反射ミラー６と走査結像面
９との間には同期信号検出用の反射ミラー７が配置され
ている。上記走査用補正レンズ5bの同期信号検出用光ビ
ーム透過部5b1を透過した光ビームは、反射ミラー６で
反射されたあと同期信号検出用反射ミラー７で反射され
て逆向きに進み、反射ミラー６で反射され、かつ、再び
走査用補正レンズ5bの同期信号検出用光ビーム透過部5b
1を透過したあと同期信号検出用受光素子８に導かれる
ようなっている。受光素子８は、回転多面鏡４による偏
向範囲の一方の側端部の光ビームを検出する。この検出
信号の出力時点から一定のタイミングで光ビーム発生手
段１において光ビームを画像信号で変調することによ
り、走査結像面９の所定の位置から画像信号が記録され
る。受光素子８に導かれる光ビームは、走査用補正レン
ズ5bの正のパワーを有する同期信号検出用光ビーム透過
部5b1を２回透過し、受光素子８の受光面上において集
束する。In FIGS. 1 and 2, a light beam generating means 1 composed of a semiconductor laser or the like can generate a light beam modulated by an image signal, and this light beam is generated by a collimating lens 2
After being converted into a parallel light flux by the laser beam, it is guided to the rotary polygonal mirror 4 through the cylindrical lens 3 and is deflected by the rotational driving of the rotary polygonal mirror 4. The deflected light beam from the rotary polygon mirror 4 passes through the imaging lens system that constitutes the fθ lens system, and is bent at a substantially right angle by the reflection mirror 6 and is formed on the scanning imaging surface 9 formed of a photosensitive drum or the like. The image is formed and the scanning image plane 9 is scanned. The image forming lens system includes an image forming lens 5a having an fθ characteristic and a scanning correction lens 5b.
The light beam at one side end of the light beam deflection range by the rotary polygon mirror 4 is a synchronizing signal detecting light beam, and the scanning correcting lens 5b through which the synchronizing signal detecting light beam passes.
The peripheral part of the is a synchronizing signal detecting light beam transmitting portion 5b 1 having a positive power. A reflection mirror 7 for detecting a synchronization signal is arranged between the reflection mirror 6 and the scanning image plane 9. The light beam transmitted through the synchronizing signal detecting light beam transmitting portion 5b 1 of the scanning correction lens 5b proceeds in the opposite direction is reflected by the synchronization signal detecting reflection mirror 7 after being reflected by the reflection mirror 6, a reflecting mirror The light beam transmitting portion 5b for detecting the synchronizing signal of the scanning correction lens 5b is reflected by 6 again.
After passing through 1 , the light is guided to the light receiving element 8 for detecting the synchronization signal. The light receiving element 8 detects the light beam at one side end of the deflection range of the rotary polygon mirror 4. By modulating the light beam with the image signal in the light beam generating means 1 at a constant timing from the time when the detection signal is output, the image signal is recorded from a predetermined position on the scanning image forming surface 9. The light beam guided to the light receiving element 8 is transmitted through the synchronizing signal detecting light beam transmitting portion 5b 1 having the positive power of the scanning correction lens 5b twice, and is focused on the light receiving surface of the light receiving element 8.
このように、上記実施例によれば、結像レンズ系を構
成する走査用補正レンズ5bの周辺部に正のパワーを有す
る同期信号検出用光ビーム透過部5b1を設けてこの光ビ
ーム透過部5b1に同期信号検出用光ビームを２回透過さ
せたあと受光素子８に導くようにしたため、受光素子８
に至る光路長を走査結像面９に至る光路長と同等にしな
がら、受光素子８に至る空間長は短くすることができ、
もって、装置の小型化を図ることができる。また、受光
素子８に至る空間長を短くするのに、光集束用のレンズ
を別部材として付加する必要もないから、より一層装置
の小型化を図ることができる。Thus, according to the above embodiment, the light beam transmitting portion is provided a synchronizing signal detecting light beam transmitting portion 5b 1 having a positive power in the peripheral portion of the scanning correction lens 5b constituting the imaging lens system Since the light beam for detecting the synchronization signal is transmitted twice to 5b 1 and then guided to the light receiving element 8, the light receiving element 8
While making the optical path length to the scanning image forming surface 9 equal to the optical path length to the light receiving element 8 can be shortened,
Therefore, the size of the device can be reduced. Further, since it is not necessary to add a lens for focusing light as a separate member in order to shorten the space length reaching the light receiving element 8, the device can be further downsized.
なお、走査用補正レンズ5bの周辺部の同期信号検出用
光ビーム透過部5b1は正のパワー、即ち、凸レンズ作用
をもっていることが必要である。上記走査用補正レンズ
5bは、一般にシリンドリカルレンズ又は変形シリンドリ
カルレンズ等が多用されている。これらのレンズのなか
には、中央部が負のパワーを有し、周辺部が正のパワー
を有するものであるので、このような形のレンズを有す
る光走査装置であれば、本発明を適用することができ
る。The synchronizing signal detecting light beam transmitting portion 5b 1 in the peripheral portion of the scanning correction lens 5b needs to have a positive power, that is, a convex lens action. Correction lens for scanning
For 5b, generally, a cylindrical lens or a modified cylindrical lens is often used. Among these lenses, the central portion has negative power and the peripheral portion has positive power. Therefore, the present invention is applicable to any optical scanning device having such a lens shape. You can
また、図示の実施例では、同期信号検出用反射ミラー
７が反射ミラー６の後方（下方）に配置されているが、
同期信号検出用反射ミラー７は走査用補正レンズ5bの後
方であればどこでもよく、例えば走査用補正レンズ5bと
反射ミラー６との間でもよい。Further, in the illustrated embodiment, the synchronization signal detecting reflection mirror 7 is arranged behind (below) the reflection mirror 6,
The reflection mirror 7 for detecting the synchronization signal may be anywhere behind the scanning correction lens 5b, for example, between the scanning correction lens 5b and the reflection mirror 6.
図示の実施例では、結像レンズ系の一部である走査用
補正レンズ5bの周辺部だけを同期信号検出用光ビームが
戻るように構成されているが、結像レンズ系を構成する
総てのレンズを同期信号検出用光ビームが戻るように構
成しても差し支えない。In the illustrated embodiment, the synchronizing signal detecting light beam is returned only to the peripheral portion of the scanning correction lens 5b which is a part of the imaging lens system. The lens may be configured so that the synchronizing signal detecting light beam returns.
（発明の効果） 本発明によれば、結像レンズ系の周辺部に正のパワー
を有する同期信号検出用光ビーム透過部を設けてこの光
ビーム透過部に同期信号検出用光ビームを２回透過させ
たあと受光素子に導くようにしたため、受光素子に至る
光路長を走査結像面に至る光路長と同等にしながら、受
光素子に至る空間長は短くすることができ、もって、装
置の小型化を図ることができる。また、受光素子に至る
空間長を短くするのに、光集束用のレンズを別部材とし
て付加する必要もないから、より一層装置の小型化を図
ることができる。(Effect of the Invention) According to the present invention, a synchronizing signal detecting light beam transmitting portion having a positive power is provided in the peripheral portion of the imaging lens system, and the synchronizing signal detecting light beam is transmitted twice to the light beam transmitting portion. Since the light is passed through and then guided to the light receiving element, the space length to the light receiving element can be shortened while making the optical path length to the light receiving element equal to the optical path length to the scanning image forming surface. Can be realized. Further, since it is not necessary to add a lens for focusing light as a separate member in order to shorten the space length reaching the light receiving element, the device can be further downsized.
第１図は本発明にかかる光走査装置の同期信号検出装置
の実施例を示す平面図、第２図は同上側面図、第３図は
同期信号検出装置を有する従来の光走査装置の例を示す
斜視図である。 １……光ビーム発生手段、４……回転多面鏡、5a,5b…
…結像レンズ系、5b1……同期信号検出用光ビーム透過
部、７……反射ミラー、８……受光素子、９……走査結
像面。FIG. 1 is a plan view showing an embodiment of a synchronizing signal detecting device of an optical scanning device according to the present invention, FIG. 2 is a side view of the same, and FIG. 3 is an example of a conventional optical scanning device having a synchronizing signal detecting device. It is a perspective view shown. 1 ... Light beam generating means, 4 ... Rotating polygon mirror, 5a, 5b ...
... Imaging lens system, 5b 1 ... Synchronous signal detecting light beam transmitting portion, 7 ... Reflecting mirror, 8 ... Light receiving element, 9 ... Scanning imaging surface.
Claims (1)
光ビーム発生手段と、この光ビーム発生手段からの光ビ
ームを偏向する回転多面鏡と、この回転多面鏡からの偏
向光ビームを走査結像面に結像させる結像レンズ系とを
有してなる光走査装置において、 上記結像レンズ系の周辺部は、正のパワーを有する同期
信号検出用光ビーム透過部となっており、 上記同期信号検出用光ビーム透過部を透過した光ビーム
を反射して再び上記同期信号検出用光ビーム透過部に導
く反射ミラーと、 上記反射ミラーで反射されかつ同期信号検出用光ビーム
透過部を透過した同期信号検出用光ビームを検出する受
光素子とを有してなる同期信号検出装置。1. A light beam generator for generating a light beam modulated by an image signal, a rotary polygon mirror for deflecting the light beam from the light beam generator, and a deflected light beam for scanning from the rotary polygon mirror. In an optical scanning device having an image forming lens system for forming an image on an image forming surface, a peripheral part of the image forming lens system is a synchronizing signal detecting light beam transmitting part having a positive power, A reflecting mirror that reflects the light beam that has passed through the synchronizing signal detecting light beam transmitting portion and guides it again to the synchronizing signal detecting light beam transmitting portion; and a reflecting signal that is reflected by the reflecting mirror and that is used for the synchronizing signal detecting light beam transmitting portion. A synchronizing signal detecting device comprising a light receiving element for detecting a transmitted synchronizing signal detecting light beam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1229549A JP2505593B2 (en) | 1989-09-05 | 1989-09-05 | Synchronous signal detection device for optical scanning device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1229549A JP2505593B2 (en) | 1989-09-05 | 1989-09-05 | Synchronous signal detection device for optical scanning device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0391713A JPH0391713A (en) | 1991-04-17 |
| JP2505593B2 true JP2505593B2 (en) | 1996-06-12 |
Family
ID=16893905
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1229549A Expired - Fee Related JP2505593B2 (en) | 1989-09-05 | 1989-09-05 | Synchronous signal detection device for optical scanning device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2505593B2 (en) |
-
1989
- 1989-09-05 JP JP1229549A patent/JP2505593B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0391713A (en) | 1991-04-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |