JP2002055289A - Light beam scanner - Google Patents
Light beam scannerInfo
- Publication number
- JP2002055289A JP2002055289A JP2000239157A JP2000239157A JP2002055289A JP 2002055289 A JP2002055289 A JP 2002055289A JP 2000239157 A JP2000239157 A JP 2000239157A JP 2000239157 A JP2000239157 A JP 2000239157A JP 2002055289 A JP2002055289 A JP 2002055289A
- Authority
- JP
- Japan
- Prior art keywords
- scanning
- synchronization
- synchronization detection
- mirror
- light beam
- 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.)
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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】本発明はデジタル複写機、プ
リンタ、ＦＡＸ等の画像形成装置の光書き込み装置とし
て使用される光ビーム走査装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light beam scanning device used as an optical writing device for an image forming apparatus such as a digital copying machine, a printer, a facsimile, and the like.
【０００２】[0002]
【従来の技術】複写機のデジタル化が進む中で、広幅機
においてもデジタル化が進む傾向にあり、さらなる高画
質が要求されている。現在Ａ１、Ａ０等の広幅デジタル
機はＬＥＤアレイが主流であるが、レーザ方式に比較し
てコスト高で、画質的にも劣ることは否めない。ただ
し、Ａ０幅ものレーザ書込みを考えた場合、光路長の長
さ、レンズの大型化、ポリゴンモータ、ミラーの大型
化、反射ミラーの長尺化、等からユニットの大型化、コ
スト高が課題となる。これを解決する手段として、従来
から主走査方向に２つの書込み系をつなぎ合わせ、広幅
の走査幅を得る方法が種々提案されている。この方法に
よればユニットのコンパクト化、低コスト化が図れる
が、つなぎ合せ部を精度良く揃えるための技術（２つの
ポリゴンの回転同期を取り、走査線のズレを補正する技
術）が難しいので、実用化には色々の課題がる。2. Description of the Related Art While digitalization of copiers is progressing, digitalization of wide-width machines is also progressing, and higher image quality is required. At present, LED arrays are mainly used for wide-width digital machines such as A1 and A0, but the cost is higher and the image quality is inferior to the laser system. However, when considering laser writing of A0 width, the size of the unit and the cost are high due to the length of the optical path, the size of the lens, the size of the polygon motor, the size of the mirror, and the length of the reflection mirror. Become. As means for solving this problem, various methods have been conventionally proposed for connecting two writing systems in the main scanning direction to obtain a wide scanning width. According to this method, the unit can be made compact and the cost can be reduced. However, it is difficult to achieve a technique for accurately aligning the joints (a technique for synchronizing the rotation of the two polygons and correcting the deviation of the scanning line). There are various issues for practical use.
【０００３】図８はこの種の技術の一例を示す光ビーム
走査装置の概略斜視図である。同図において、図８の左
半分の光学系を第１光学系１００、右半分を第２光学系
２００と呼ぶ。第１光学系１００において、図示されな
い駆動装置に制御されて発光手段としてのレーザダイオ
ード（以下、「ＬＤ」と称す。）１−１は画像信号に応
じて変調されたレーザ光を発光する。コリメートレンズ
２−１で平行光とされたビームはシリンドリカルレンズ
３−１を経て、ポリゴンンミラー４に入射する。ポリゴ
ンミラー４で反射、走査されたレーザ光は第１、第２の
Ｆθレンズ５−１，６−１によってそれぞれ等角速度偏
向から等速度偏向に変更され、第１、第２、第３の折返
しミラー７−１、８−１、９−１によって反射され、感
光体ドラム１０方向に導かれ、走査位置のほぼ中央の所
定位置から端部に向かって走査される。FIG. 8 is a schematic perspective view of a light beam scanning device showing an example of this kind of technology. 8, the left half optical system in FIG. 8 is referred to as a first optical system 100, and the right half is referred to as a second optical system 200. In the first optical system 100, a laser diode (hereinafter, referred to as “LD”) 1-1 as a light emitting unit is controlled by a driving device (not shown) to emit a laser beam modulated according to an image signal. The beam converted into parallel light by the collimating lens 2-1 passes through the cylindrical lens 3-1 and enters the polygon mirror 4. The laser light reflected and scanned by the polygon mirror 4 is changed from constant angular velocity deflection to constant velocity deflection by the first and second Fθ lenses 5-1 and 6-1 respectively, and the first, second and third folds are provided. The light is reflected by the mirrors 7-1, 8-1, and 9-1, guided toward the photosensitive drum 10, and scanned from a predetermined position substantially at the center of the scanning position toward the end.
【０００４】また、第２光学系２００は第１光学系１０
０をポリゴンミラーを中心に１８０°回転させた位置に
配置されていて、ＬＤ１−１から出射したレーザ光１−
２は同様な経路を経て感光体ドラム１０に至り、走査位
置のほぼ中央の所定位置から、第１光学系１００とは逆
方向の端部に向かって走査される。[0004] The second optical system 200 is connected to the first optical system 10.
0 is disposed at a position rotated by 180 ° about the polygon mirror, and the laser light 1 emitted from the LD 1-1
Reference numeral 2 reaches the photosensitive drum 10 via a similar path, and is scanned from a predetermined position substantially at the center of the scanning position toward the end in the direction opposite to the first optical system 100.
【０００５】１１−１、１１−２及び１６−１、１６−
２はそれぞれ第１、第２光学系１００，２００の同期検
知ユニットと同期検知ミラーで、各同期検知ユニット１
１−１，１１−２はレーザビームの画像領域外に設けら
れ、レーザビームの１走査毎にレーザビームの走査タイ
ミングを検知する。図示しない書込み制御回路はこの検
知したタイミングに応じてレーザビームの走査タイミン
グと書き込み開始位置との同期をとる。[0005] 11-1, 11-2 and 16-1, 16-
Reference numeral 2 denotes a synchronization detection unit and a synchronization detection mirror of the first and second optical systems 100 and 200, respectively.
1-1 and 11-2 are provided outside the image area of the laser beam, and detect the scanning timing of the laser beam for each scanning of the laser beam. A writing control circuit (not shown) synchronizes the scanning timing of the laser beam with the writing start position in accordance with the detected timing.
【０００６】図９はこれを上方から見た概略図で、太い
２点鎖線は走査光が反射ミラーで反射される位置を、太
い１点鎖線は感光体ドラム１０の中心線を、細い１点鎖
線は走査ビームの光軸をそれぞれ示している。また、矢
印１３はポリゴンミラーの回転方向を、矢印１４は感光
体ドラム１０上で走査線が走査される方向を示してい
る。FIG. 9 is a schematic view of this as viewed from above. The thick two-dot chain line indicates the position where the scanning light is reflected by the reflecting mirror, the thick one-dot chain line indicates the center line of the photosensitive drum 10, and the thin one point. The dashed lines indicate the optical axes of the scanning beams, respectively. Arrow 13 indicates the direction of rotation of the polygon mirror, and arrow 14 indicates the direction in which scanning lines are scanned on the photosensitive drum 10.
【０００７】図１０は図９の光学系でミラー８−１、８
−２で折り返された後のビームの軌跡と、同期検知ミラ
ー１６−１，１６−２および同期検知ユニット１１−
１，１１−２との位置関係を示す図、図１１および図１
２は光路を側面から見た図であり、図１１は第１光学系
だけを、図１２は第２光学系も含めた位置関係を示して
いる。図１３は図１０を長手方向の側面から見た図であ
る。なお、図１０（Ｂ）および図１３（Ｂ）はそれぞれ
図１０（Ａ）および図１３（Ａ）の中央部分の拡大図で
ある。FIG. 10 shows the optical system shown in FIG.
-2, the trajectory of the beam after turning back, the synchronization detection mirrors 16-1 and 16-2, and the synchronization detection unit 11-
FIG. 11 and FIG.
2 is a side view of the optical path, FIG. 11 shows a positional relationship including only the first optical system, and FIG. 12 shows a positional relationship including the second optical system. FIG. 13 is a view of FIG. 10 viewed from a side surface in the longitudinal direction. Note that FIGS. 10B and 13B are enlarged views of the central portion of FIGS. 10A and 13A, respectively.
【０００８】各光学系の同期光は第３ミラー９−１、２
で反射した後、第３ミラー９−１，２と感光体ドラム１
０の間に設置された同期検知ミラー１６−１、２でそれ
ぞれ折り返されて、感光体ドラム相当位置に設置された
同期検知ユニット１１−１、２に入射する。同期検知ミ
ラー１６−１，２はそれぞれ副走査方向に傾けられ、同
期光を各々の同期検知ユニット１１−１，２に導いてい
る。また、これら光書込み装置は、通常、ほこり等の付
着をきらうため、図示しない光学箱内部に密閉され、精
度良く固定、配置されている。ただし、レーザの出射口
は開放する必要があるため、１２の防塵ガラスを配置し
て、ホコリの侵入を防いでいる。The synchronous light of each optical system is transmitted to third mirrors 9-1 and 2-1.
And then the third mirrors 9-1 and 9-1 and the photosensitive drum 1
The light is turned back by the synchronization detection mirrors 16-1 and 16-2 provided between 0, respectively, and enters the synchronization detection units 11-1 and 11 provided at positions corresponding to the photosensitive drums. The synchronization detection mirrors 16-1 and 16-2 are tilted in the sub-scanning direction, and guide synchronization light to the respective synchronization detection units 11-1 and 11-2. These optical writing devices are usually hermetically sealed inside an optical box (not shown), and fixed and arranged with high precision in order to prevent adhesion of dust and the like. However, since the laser emission port needs to be opened, twelve dustproof glasses are arranged to prevent dust from entering.
【０００９】以上述べた光ビーム走査装置では、１つの
偏向手段の異なる偏向面に２つのビームを入射、偏向し
て、それぞれ異なる結像光学系で被走査面上の一つの走
査領域を、２分割して光走査している。１つの偏向手段
により２つの走査線は同時に走査されるため、副走査方
向の走査線のずれは発生しにくい。さらにそれぞれの走
査線が走査領域のほぼ中央部から両端部に向かって走査
されるため、ほぼ中央部に同期検知を設けることが可能
で、走査線の主走査方向の繋ぎ合せを精度よく行うこと
ができる。In the light beam scanning apparatus described above, two beams are made incident on and deflected on different deflecting surfaces of one deflecting means, and one scanning area on the surface to be scanned is changed by two different imaging optical systems. Light scanning is performed in a divided manner. Since two scanning lines are simultaneously scanned by one deflecting unit, a shift of the scanning lines in the sub-scanning direction hardly occurs. Furthermore, since each scanning line is scanned from substantially the center to both ends of the scanning area, synchronization detection can be provided substantially at the center, and the scanning lines can be accurately joined in the main scanning direction. Can be.
【００１０】次に同期検知ユニット１１−１，２による
走査ビーム位置の検出方法について説明する。Next, a method of detecting the scanning beam position by the synchronization detecting units 11-1 and 11-2 will be described.
【００１１】図１４の同期検知板１６は三角形の受光部
１６１を有し、ビームの出口側１６２が傾きθの斜辺と
なっている。初期のビーム走査位置ずれの無い状態のビ
ーム通過位置をＡとした時、同期検知信号検出時間がｔ
Aであったとする。The synchronization detecting plate 16 shown in FIG. 14 has a triangular light receiving section 161 and the exit side 162 of the beam is a hypotenuse of the inclination θ. Assuming that the beam passing position in the state where there is no initial beam scanning position shift is A, the synchronization detection signal detection time is t
Suppose A.
【００１２】温度変動により位置ズレの発生した時のビ
ーム通過位置をＢとしその同期信号検出時間がｔBに変
化したとする。この時のビーム位置変動量ｐｖは、ビー
ムの走査速度をＶ、センサーの斜辺の角度をθとすると ｐｖ＝Ｖ・(ｔA−ｔB)／tanθ＝Ｖ・Δｔ／tanθ として求めることができる。It is assumed that the beam passing position when the position shift occurs due to the temperature fluctuation is B and the synchronization signal detection time has changed to tB. The beam position fluctuation amount pv at this time can be obtained as pv = V · (tA−tB) / tan θ = V · Δt / tan θ where V is the scanning speed of the beam and θ is the angle of the oblique side of the sensor.
【００１３】また、図１５のように、２つのセンサで構
成され、出口側のセンサーを４５°傾けた同期検知板１
６を使用した場合、２つのセンサ１６３，１６４間のビ
ーム通過時間の差によりビーム走査位置のずれ量は ｐｖ＝Ｖ・Δｔ／tanθ （ただし tanθ＝１） ＝Ｖ・Δｔ により求めることができる。Further, as shown in FIG. 15, a synchronous detection plate 1 composed of two sensors, wherein the sensor on the outlet side is inclined by 45 °.
6, the deviation of the beam scanning position can be obtained from the difference in beam passage time between the two sensors 163 and 164 by the following equation: pv = V ＝ Δt / tanθ (where tanθ = 1) = V ・ Δt.
【００１４】第１、 第２同期検知により検出された２
つのビームの変化量を合計し、ビーム走査位置補正手段
によりこの量に等しいだけビーム位置を補正すれば、温
度変動等によっても２つのビームに位置ズレの無い良質
な画像を得ることができる。主走査方向の書き出し位置
を決めるための同期信号としては、ビーム走査位置によ
り変化しない検出信号１を使用する。The two signals detected by the first and second synchronization detections
By summing the amounts of change of the two beams and correcting the beam position by the beam scanning position correcting means by an amount equal to this amount, a high-quality image can be obtained in which the two beams are not displaced due to temperature fluctuation or the like. As a synchronization signal for determining a write start position in the main scanning direction, a detection signal 1 that does not change with the beam scanning position is used.
【００１５】[0015]
【発明が解決しようとする課題】従来においては、前述
のように２つの書込系はそれぞれ個別の同期ミラーを有
している。その同期ミラーは最終折り返しミラーと、感
光体との間に設置され、最終折り返しミラーより上流の
光学素子や、それを保持するハウジング等の熱変形によ
るビーム位置ずれの挙動は、同期検知位置で正確に検出
することは可能であった。ただし、２枚の同期ミラーが
固定部材の熱変形等の理由によりその相対的位置、姿勢
が変化した場合には、これを前者の要因から生じる挙動
と判別することは困難で、ビーム相対位置ずれ量検出時
の誤差となっていた。Conventionally, as described above, each of the two writing systems has an individual synchronous mirror. The synchronization mirror is installed between the final folding mirror and the photoconductor, and the behavior of the beam position shift due to thermal deformation of the optical element upstream of the final folding mirror and the housing that holds it is accurate at the synchronization detection position. It was possible to detect. However, if the relative position and orientation of the two synchronous mirrors change due to thermal deformation of the fixed member, etc., it is difficult to judge this as the behavior caused by the former factor, and the beam relative position shift It was an error when detecting the amount.
【００１６】また、従来の書込系においては、同期光の
戻り光防止対策として、同期光に対し同期検知板を主走
査方向に傾けているが、主走査方向にはほぼ垂直に設置
している。さらに、感光体ドラムからの戻り光対策とし
ては、通常走査ビームの感光体への入射角を副走査方向
に傾けたレイアウトとしている。このため、走査ビーム
の位置ずれが生じた際に、感光体上でのビーム位置変化
量は、同期検知位置で縮小されるため、結果として検出
精度を落としていた。Further, in the conventional writing system, as a countermeasure for preventing return of the synchronization light, the synchronization detection plate is inclined in the main scanning direction with respect to the synchronization light, but is installed substantially perpendicular to the main scanning direction. I have. Further, as a measure against return light from the photosensitive drum, the layout is such that the incident angle of the normal scanning beam on the photosensitive member is inclined in the sub-scanning direction. For this reason, when the positional deviation of the scanning beam occurs, the amount of change in the beam position on the photoconductor is reduced at the synchronous detection position, and as a result, the detection accuracy is reduced.
【００１７】本発明は、このような従来技術の実情に鑑
みてなされたもので、その目的は、１つのポリゴンミラ
ーで２つの書込み系を走査することによりポリゴンの同
期をとる必要をなくし、さらに２つのビーム走査をほぼ
中央部から開始する構成にしたことにより主走査方向の
繋ぎ合せを容易にすることにある。また、他の目的は、
温度変動等による同期ミラーの姿勢変化によるビームの
相対位置ズレを無くし、ビーム相対位置ズレ量の検出精
度を上げるとともに、装置を簡略化することにある。The present invention has been made in view of such a situation of the prior art, and has as its object to eliminate the need to synchronize polygons by scanning two writing systems with one polygon mirror. An object of the present invention is to facilitate joining in the main scanning direction by employing a configuration in which two beam scans are started almost from the center. Also, for other purposes,
An object of the present invention is to eliminate a relative positional deviation of a beam due to a change in attitude of a synchronous mirror due to a temperature change or the like, to improve the accuracy of detecting a relative positional deviation amount of a beam, and to simplify the apparatus.
【００１８】また、他の目的は、感光体上と同期検知板
上でのビーム位置ずれ量を等しくし、ズレ量を正確に検
出することにある。Another object of the present invention is to make the amount of beam misalignment on the photoreceptor equal to that on the synchronous detection plate and accurately detect the amount of misalignment.
【００１９】さらに他の目的は、感光体上でのビーム位
置ずれ量を、同期検知位置で拡大することにより検出感
度を上げることにある。Still another object is to increase the detection sensitivity by enlarging the beam position shift amount on the photoconductor at the synchronization detection position.
【００２０】[0020]
【課題を解決するための手段】前記目的を達成するた
め、本発明は、１つの偏向手段を使用して２つの書き込
み光学系により光ビームを感光体ドラムの所定位置から
端部に向かって走査して画像を形成する光ビーム走査装
置において、光ビームの１走査毎にレーザビームの走査
タイミングを検知する同期検知板に光ビームを導く同期
検知ミラーを２つの書込み系で共通化した。According to the present invention, a light beam is scanned from a predetermined position of a photosensitive drum toward an end by two writing optical systems using one deflection means. In a light beam scanning apparatus for forming an image by scanning, a synchronization detection mirror for guiding a light beam to a synchronization detection plate for detecting a scanning timing of a laser beam for each scanning of the light beam is shared by two writing systems.
【００２１】この場合、前記感光体上と同期検知板上で
のビームの移動量を等しくするようにする。また、前記
同期検知板への副走査方向の入射角を走査ビームの感光
体への副走査方向入射角と等しくする。あるいは、前記
同期検知板への副走査方向入射角を走査ビームの感光体
への副走査方向入射角より大きくする。In this case, the amount of movement of the beam on the photosensitive member and the amount of movement of the beam on the synchronization detecting plate are made equal. Further, the incident angle in the sub-scanning direction on the synchronization detection plate is made equal to the incident angle of the scanning beam on the photoconductor in the sub-scanning direction. Alternatively, the incident angle in the sub-scanning direction on the synchronization detection plate is made larger than the incident angle in the sub-scanning direction of the scanning beam on the photoconductor.
【００２２】[0022]
【発明の実施の形態】以下、本発明の実施形態について
図面を参照して説明する。なお、以下の説明において前
述の従来例と同等な各部には同一の参照符号を付し、重
複する説明は省略する。Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts as those in the above-described conventional example are denoted by the same reference numerals, and overlapping description will be omitted.
【００２３】図１および図２に本発明の実施形態に係る
光ビーム走査装置のミラー８−１、８−２で折り返され
た後のビームの軌跡と、同期検知ミラー１６−１，１６
−２および同期検知ユニット１１−１，１１−２との位
置関係を示す。同図から分かるように、この実施形態
は、前述の従来例における図１０に対応するもので、従
来では第１光学系１００と第２光学系２００のそれぞれ
に設けられていた同期検知ミラー１６−１，２を１枚と
し、感光体ドラム１０の上方、ほぼ中央部に２枚の同期
検知板１１−１、１１−２をその１枚の同期検知ミラー
１６に隣合せに設置している。その他の各部は前述の従
来例を同等に構成されている。FIGS. 1 and 2 show the trajectory of the beam after being turned back by the mirrors 8-1 and 8-2 of the light beam scanning device according to the embodiment of the present invention, and the synchronization detecting mirrors 16-1 and 16-1.
2 shows a positional relationship between the sync detection units 11-1 and 11-2. As can be seen from the figure, this embodiment corresponds to FIG. 10 in the above-described conventional example, and the synchronization detection mirror 16-which is conventionally provided in each of the first optical system 100 and the second optical system 200. One and two are one, and two synchronization detecting plates 11-1 and 11-2 are provided adjacent to the one synchronization detecting mirror 16 in a substantially central portion above the photosensitive drum 10. The other components are the same as those of the above-described conventional example.
【００２４】同期検知板１１−１，２は感光体相当位置
に置かれているので、感光体ドラム１０と同期検知板１
１−１，２は同期検知ミラー１６に関して対称な位置関
係に有り、同期検知板１１−１，２上を走査する同期ビ
ームも一直線上に整列する。Since the synchronization detecting plates 11-1 and 11-2 are located at positions corresponding to the photosensitive members, the photosensitive drum 10 and the synchronization detecting plates 1
1-1 and 1-2 have a symmetrical positional relationship with respect to the synchronization detection mirror 16, and the synchronization beams that scan the synchronization detection plates 11-1 and 11-2 are also aligned.
【００２５】このように配置した場合、熱膨張等により
同期検知ミラー１６の姿勢が変化すると、同期検知板１
１−１，２上を走査する同期ビーム走査位置も変化する
が、同期検知ミラー１６が２つの光学系で共通なため、
その変化量は等しくなり、２つのビームの相対位置は変
化しない。In this arrangement, when the attitude of the synchronization detection mirror 16 changes due to thermal expansion or the like, the synchronization detection plate 1
Although the synchronous beam scanning position for scanning on 1-1 and 1-2 also changes, since the synchronous detection mirror 16 is common to the two optical systems,
The change amounts are equal, and the relative positions of the two beams do not change.
【００２６】画像上目立ち易く問題となるのは、２つの
ビームの繋ぎ合せ部における相対的な位置ずれ（線の不
連続の度合い）であり、画像上での走査線位置の多少の
ずれは人間の目ではそれと識別できないため、特に問題
とはならない。ただし、この実施例のレイアウトのよう
に実際に構成部品を配置しようとすると、ポリゴンスキ
ャナ４、同期検知板１１−１，２、第３折り返しミラー
９−１，２、同期検知ミラー１６がすべて中央部に集中
し、スペース的に余裕が無く、取付が困難であった。ま
た、熱源となりうるポリゴンスキャナ４の直下に同期検
知板１１−１，２を配置するため、不具合が生じ易いと
いえる。The problem that is noticeable on the image is a relative displacement (degree of line discontinuity) at the joint portion of the two beams, and a slight displacement of the scanning line position on the image is a problem for humans. This is not a problem, since it cannot be distinguished from it. However, when actually arranging the components as in the layout of this embodiment, the polygon scanner 4, the synchronization detection plates 11-1, 1-2, the third folding mirrors 9-1, 9-1, and the synchronization detection mirror 16 are all located at the center. It was difficult to install because there was no room in the space. In addition, since the synchronization detection plates 11-1 and 11-2 are disposed immediately below the polygon scanner 4 that can be a heat source, it can be said that a problem is likely to occur.
【００２７】そこで、この点を改良したのが、図３およ
び図４に示した実施形態である。The embodiment shown in FIGS. 3 and 4 improves this point.
【００２８】この実施形態では同期検知ミラー１６ａを
副走査方向にほぼ４５°傾けて、同期光を横方向に取り
出すようにした。このため、同期検知板１１−１，２が
他の構成部材から十分な距離をおいて配置できて、各構
成部材の配置が容易となった。In this embodiment, the synchronization detection mirror 16a is inclined at approximately 45 ° in the sub-scanning direction, and the synchronization light is extracted in the horizontal direction. For this reason, the synchronization detecting plates 11-1 and 11-2 can be arranged at a sufficient distance from other constituent members, and the arrangement of each constituent member is facilitated.
【００２９】すなわち、第１、 第２光学系１００，２
００の感光体ドラム１０への副走査方向ビーム入射角を
それぞれθ1、θ2、同期検知板１１−１，２への第１、
第２の光学系１００，２００の同期光の副走査方向ビー
ム入射角をθ’1、θ’2とする。ここで、第２光学系２
００の走査ビーム位置が距離ｄ2移動したとすると、そ
の時の感光体ドラム１０上のビームの移動距離Ｌ2はそ
の量が微少な場合にはビーム入射点Ｐにおける接線上で
の距離にほぼ等しく Ｌ2 ≒ ｄ2／ｃｏｓθ2 で表わすことができる。That is, the first and second optical systems 100 and 2
00, the beam incident angles in the sub-scanning direction on the photosensitive drum 10 are θ1 and θ2, respectively.
The incident angles of the synchronous light beams in the sub-scanning direction of the second optical systems 100 and 200 are θ′1 and θ′2. Here, the second optical system 2
Assuming that the scanning beam position of 00 has moved the distance d2, the moving distance L2 of the beam on the photosensitive drum 10 at that time is almost equal to the distance on the tangent line at the beam incident point P when the amount is small. d2 / cos θ2.
【００３０】また、この時の同期検知板１１−１，２上
でのビーム移動距離ｍ2は ｍ2 ＝ ｄ2 ／ ｃｏｓθ’2 と表わすことができる。At this time, the beam moving distance m2 on the synchronization detecting plates 11-1 and 11-2 can be expressed as m2 = d2 / cos θ'2.
【００３１】そこで、この実施形態では、 θ2 ＝ θ’2 となるように同期検知板１１−１，２を設置して、 Ｌ2 ≒ ｍ2 とし、感光体ドラム１０上と同期検知板１１−１，２上
のビーム移動量が等しくなるようにした。Therefore, in this embodiment, the synchronous detection plates 11-1 and 11-2 are installed so that θ2 = θ'2, and L2 ≒ m2, so that the synchronous detection plates 11-1 and 11-1 2 so that the beam movement amounts on them were equal.
【００３２】この時、第１光学系１００に関しても下に
示した同様な関係が成り立つ。At this time, the same relationship as shown below holds for the first optical system 100.
【００３３】Ｌ1 ≒ ｄ1／ ｃｏｓθ1 ｍ1 ＝ ｄ1／ ｃｏｓθ’1 θ1 ＝ θ’′1 Ｌ1 ≒ ｍ1 この構成によれば、ビームの位置ズレ量をより正確に検
出できるため、検出精度を上げることができる。L1 ≒ d1 / cos θ1 m1 = d1 / cos θ′1 θ1 = θ′′1 L1 ≒ m1 With this configuration, the amount of displacement of the beam can be detected more accurately, and the detection accuracy can be increased. .
【００３４】図１と図２、および図３と図４にそれぞれ
示した２つの実施形態では、第１および第２光学系１０
０，２００の各書込みビームの感光体ドラム１０への入
射角が異なっていた。このため、同期検知ミラー１６ａ
は大きくならざるをえず、またこのようなレイアウトの
場合、感光体ドラム１０の振れにより副走査方向のビー
ム位置ずれが発生する。そこでこの点を改良した実施形
態を図５ないし図７に示す。In the two embodiments shown in FIGS. 1 and 2, and FIGS. 3 and 4, respectively, the first and second optical systems 10
The angles of incidence of the 0, 200 writing beams on the photosensitive drum 10 were different. Therefore, the synchronization detection mirror 16a
Inevitably increases, and in such a layout, a beam position shift in the sub-scanning direction occurs due to the shake of the photosensitive drum 10. Therefore, an embodiment in which this point is improved is shown in FIGS.
【００３５】この実施形態は、２つの光学系１００，２
００の２つのビームが感光体ドラム１０に等しい角度で
入射する様に、第３ミラー９−１，２上のビーム反射位
置を一直線状に配置したことを特徴とする。図５はこの
実施形態に係る光学系を右側面から見た図、図６は第３
ミラー９−１，２、同期検知ミラー１６ｂ、および同期
検知板１１−１，２の位置関係を示す斜視図、図７は図
６を上面より見た図である。図７の太い矢印はビームが
走査する方向を示しており、２つの同期ビームは同期検
知ミラー１６ｂ位置でクロスし、同期検知ミラー１６ｂ
上の同じ位置を逆方向に横切る。さらに、同期検知板１
１−１，２も一直線状に、それぞれの光学系とは逆の位
置に配置され、同期光はそれぞれ逆方向より中央方向に
向って走査する。In this embodiment, two optical systems 100 and 2
The beam reflection positions on the third mirrors 9-1 and 9-1 are arranged in a straight line so that the two beams of 00 are incident on the photosensitive drum 10 at an equal angle. FIG. 5 is a view of the optical system according to this embodiment as viewed from the right side, and FIG.
FIG. 7 is a perspective view showing the positional relationship between the mirrors 9-1 and 9-1, the synchronization detection mirror 16b, and the synchronization detection plates 11-1 and 11-2. FIG. The thick arrow in FIG. 7 indicates the scanning direction of the beam, and the two synchronization beams cross at the position of the synchronization detection mirror 16b, and the synchronization detection mirror 16b
Cross the same location above in the opposite direction. Furthermore, the synchronization detection plate 1
1-1 and 1-2 are also arranged in a straight line at positions opposite to the respective optical systems, and the synchronous light scans toward the center from the opposite directions.
【００３６】このような配置とすることにより、同期検
知ミラー１６ｂを小型化し、装置全体をよりシンプルに
できた。With such an arrangement, the size of the synchronization detecting mirror 16b can be reduced, and the entire apparatus can be simplified.
【００３７】この実施例でも 、感光体への走査ビーム
入射角 θ＝同期検知板への同期ビーム入射角 θ’とす
れば、感光体上と同期検知板上でのビームの移動量を等
しくすることができてビーム移動量の検出精度が上が
る。なお、このように感光体ドラム１０への走査ビーム
入射角θを同期検知板１１−１，２への同期ビーム入射
角θ’と等しくすることにより感光体ドラム１０上と同
期検知板１１−１，２上でのビームの移動量を等しくす
る代わりに、例えば、 ｃｏｓθ ＝ Ｎ ｃｏｓθ’ の関係が成り立つように同期検知板１１−１，２を傾け
て、θに対してθ’を設定してやれば、 ｍ ＝ Ｎ Ｌ となり、検出感度をＮ倍とすることができる。Also in this embodiment, if the incident angle of the scanning beam on the photosensitive member θ = the incident angle of the synchronous beam on the synchronous detecting plate θ ′, the movement amount of the beam on the photosensitive member and on the synchronous detecting plate are equalized. As a result, the detection accuracy of the beam movement amount increases. By making the incident angle θ of the scanning beam on the photosensitive drum 10 equal to the incident angle θ ′ of the synchronous beam on the synchronous detection plates 11-1 and 11-2 in this manner, the position on the photosensitive drum 10 and the synchronous detection plate 11-1 are changed. , 2 instead of equalizing the amount of movement of the beam, for example, by tilting the synchronous detection plates 11-1 and 11-2 so that the relationship of cos θ = N cos θ ′ holds, and setting θ ′ to θ , M = NL, and the detection sensitivity can be increased N times.
【００３８】このように検出感度を等倍とするかＮ倍と
するかは、設計条件に応じて適宜選択することができ
る。As described above, whether the detection sensitivity is made equal or N times can be appropriately selected according to design conditions.
【００３９】[0039]
【発明の効果】以上のように、光ビームの１走査毎にレ
ーザビームの走査タイミングを検知する同期検知板に光
ビームを導く同期検知ミラーを２つの書込み系で共通化
し１枚としたので、温度変動等による各同期ミラーの姿
勢変化によるビームの相対位置ズレを無くして、ビーム
相対位置ズレ量の検出精度を上げ、装置を簡略化するこ
とができる。As described above, the synchronous detection mirror for guiding the light beam to the synchronous detection plate for detecting the scanning timing of the laser beam for each scanning of the light beam is shared by the two writing systems to be one. The relative position shift of the beam due to the change in the attitude of each synchronous mirror due to the temperature fluctuation or the like is eliminated, the detection accuracy of the amount of relative position shift of the beam is increased, and the apparatus can be simplified.
【００４０】請求項２記載の発明によれば、感光体上と
同期検知板上でのビームの移動量を等しくするので、ビ
ームの位置ズレ量をより正確に検出できるため、検出精
度を上げることができる。According to the second aspect of the present invention, since the amount of movement of the beam on the photosensitive member and the amount of movement of the beam on the synchronization detecting plate are made equal, the amount of displacement of the beam can be detected more accurately, so that the detection accuracy is improved. Can be.
【００４１】請求項３記載の発明によれば、同期検知セ
ンサへの副走査方向入射角を走査ビームの感光体への副
走査方向入射角と等しくしたので、感光体上と同期検知
板上でのビーム位置ずれ量を等しくすることが可能で、
ビーム位置ズレ量を正確に検出することができる。According to the third aspect of the invention, the incident angle in the sub-scanning direction on the synchronous detection sensor is made equal to the incident angle of the scanning beam on the photoreceptor in the sub-scanning direction. It is possible to equalize the beam position shift amount of
The beam position shift amount can be accurately detected.
【００４２】請求項４記載の発明によれば、同期検知セ
ンサへの副走査方向入射角を走査ビームの感光体への副
走査方向入射角より大きくしたので、感光体上でのビー
ム位置ずれ量を、同期検知位置で拡大することが可能
で、によりビーム位置スレの検出感度を上げることがで
きる。According to the fourth aspect of the present invention, the angle of incidence of the scanning beam on the photosensitive member in the sub-scanning direction is made larger than the angle of incidence of the scanning beam on the photosensitive member. Can be expanded at the synchronization detection position, and the detection sensitivity of the beam position thread can be increased.
【図１】本発明の実施形態に係る光ビーム走査装置のミ
ラーで折り返された後のビームの軌跡と、同期検知ミラ
ーおよび同期検知ユニットとの位置関係を示す図であ
る。FIG. 1 is a diagram showing a trajectory of a beam after being turned back by a mirror of a light beam scanning device according to an embodiment of the present invention and a positional relationship between a synchronization detection mirror and a synchronization detection unit.
【図２】図１の関係を側面から見た図である。FIG. 2 is a side view of the relationship shown in FIG. 1;
【図３】同期検知ミラーを副走査方向にほぼ４５°傾け
た実施形態の光路とともに各部の配置を示す側面図であ
る。FIG. 3 is a side view showing the arrangement of each part together with the optical path of the embodiment in which the synchronization detection mirror is inclined by approximately 45 ° in the sub-scanning direction.
【図４】図３の同期検知ミラ部分を拡大した図である。FIG. 4 is an enlarged view of a synchronization detecting mirror portion of FIG. 3;
【図５】副走査方向のビーム位置ずれの発生を抑える実
施形態の各部の配置を光路とともに示す側面図である。FIG. 5 is a side view showing an arrangement of each unit in the embodiment for suppressing occurrence of a beam position shift in a sub-scanning direction together with an optical path.
【図６】図５の同期検知ミラーと同期検知ユニットと第
３折り返しミラーとの関係を示す斜視図である。FIG. 6 is a perspective view illustrating a relationship among a synchronization detection mirror, a synchronization detection unit, and a third folding mirror in FIG. 5;
【図７】図６を上方から見た図である。FIG. 7 is a view of FIG. 6 as viewed from above.
【図８】従来から実施されている光ビーム走査装置の一
構成を示す概略斜視図である。FIG. 8 is a schematic perspective view showing one configuration of a light beam scanning device conventionally implemented.
【図９】図８を上方から見た図である。FIG. 9 is a view of FIG. 8 as viewed from above.
【図１０】図９の光学系でミラーで折り返された後のビ
ームの軌跡と、同期検知ミラーおよび同期検知ユニット
との位置関係を示す図である。FIG. 10 is a diagram showing a trajectory of a beam after being turned back by a mirror in the optical system of FIG. 9 and a positional relationship between a synchronization detection mirror and a synchronization detection unit.
【図１１】図１０の光路を側面から見た図で、第１光学
系のみを示す。11 is a side view of the optical path of FIG. 10, showing only the first optical system.
【図１２】図１０の光路を側面から見た図で、第１およ
び第２光学系を示す。FIG. 12 is a side view of the optical path in FIG. 10, showing first and second optical systems.
【図１３】図１０を長手方向の側面から見た図である。FIG. 13 is a view of FIG. 10 as viewed from the side in the longitudinal direction.
【図１４】同期検知板の一例をタイミングチャートとと
もに示す図である。FIG. 14 is a diagram showing an example of a synchronization detection plate together with a timing chart.
【図１５】同期検知板の他の例をタイミングチャートと
もに示す図である。FIG. 15 is a diagram showing another example of the synchronization detection plate together with a timing chart.
１−１，１−２ ＬＤ ２−１，２−２ こりメートレンズ ３−１，３−２ シリンドリカルレンズ ４ ポリゴンミラー ５−１，５−２，６−１，６−２ Ｆθレンズ ７−１，７−２，８−１，８−２，９−１，９−２ 折
り返しミラー １０ 感光体ドラム １１−１，１１−２ 同期検知ユニット（同期検知板） １６，１６ａ，１６ｂ 同期検知ミラー1-1, 1-2 LD 2-1, 2-2 Dummy lens 3-1, 3-2 Cylindrical lens 4 Polygon mirror 5-1, 5-2, 6-1, 6-2 Fθ lens 7-1 , 7-2, 8-1, 8-2, 9-1, 9-2 Folding mirror 10 Photoconductor drum 11-1, 11-2 Synchronous detection unit (synchronous detection plate) 16, 16a, 16b Synchronous detection mirror
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 2C362 BA53 BA69 BA83 BA90 BB30 DA03 DA04 2H045 AA01 BA02 BA22 BA36 5C072 AA03 BA01 BA02 BA17 DA04 FB03 HA02 HA06 HA08 HA13 HB08 HB11 HB13 HB15 XA01 XA03 XA04 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2C362 BA53 BA69 BA83 BA90 BB30 DA03 DA04 2H045 AA01 BA02 BA22 BA36 5C072 AA03 BA01 BA02 BA17 DA04 FB03 HA02 HA06 HA08 HA13 HB08 HB11 HB13 HB15 XA01 XA03 XA04
Claims (4)
み光学系により光ビームを感光体の所定位置から端部に
向かって走査して画像を形成する光ビーム走査装置にお
いて、 光ビームの１走査毎にレーザビームの走査タイミングを
検知する同期検知板に光ビームを導く同期検知ミラーを
前記２つの書込み系で共通化したことを特徴とする光ビ
ーム走査装置。1. A light beam scanning apparatus for forming an image by scanning a light beam from a predetermined position on a photosensitive member toward an end by two writing optical systems using one deflection means. A light beam scanning device, wherein a synchronization detection mirror for guiding a light beam to a synchronization detection plate for detecting a scanning timing of a laser beam for each scan is shared by the two writing systems.
の移動量を等しくすることを特徴とする請求項１記載の
光ビーム走査装置。2. The light beam scanning device according to claim 1, wherein the amount of movement of the beam on the photoconductor and the amount of movement of the beam on the synchronization detection plate are made equal.
走査ビームの感光体への副走査方向入射角と等しくした
ことを特徴とする請求項１記載の光ビーム走査装置。3. The light beam scanning device according to claim 1, wherein the incident angle in the sub-scanning direction on the synchronization detecting plate is equal to the incident angle of the scanning beam on the photosensitive member in the sub-scanning direction.
走査ビームの感光体への副走査方向入射角より大きくし
たことを特徴とする請求項１記載の光ビーム走査装置。4. The light beam scanning device according to claim 1, wherein an incident angle in the sub-scanning direction on the synchronization detecting plate is larger than an incident angle of the scanning beam on the photosensitive member in the sub-scanning direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000239157A JP2002055289A (en) | 2000-08-07 | 2000-08-07 | Light beam scanner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000239157A JP2002055289A (en) | 2000-08-07 | 2000-08-07 | Light beam scanner |
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| Publication Number | Publication Date |
|---|---|
| JP2002055289A true JP2002055289A (en) | 2002-02-20 |
Family
ID=18730744
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
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| Country | Link |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2018502741A (en) * | 2015-12-17 | 2018-02-01 | ヴェーエムイー ホーランド ベー． ヴェー．Ｖｍｉ Ｈｏｌｌａｎｄ Ｂ． Ｖ． | Joining device for joining tire parts |
-
2000
- 2000-08-07 JP JP2000239157A patent/JP2002055289A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2018502741A (en) * | 2015-12-17 | 2018-02-01 | ヴェーエムイー ホーランド ベー． ヴェー．Ｖｍｉ Ｈｏｌｌａｎｄ Ｂ． Ｖ． | Joining device for joining tire parts |
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