JPS636870B2 - - Google Patents
Info
- Publication number
- JPS636870B2 JPS636870B2 JP57128189A JP12818982A JPS636870B2 JP S636870 B2 JPS636870 B2 JP S636870B2 JP 57128189 A JP57128189 A JP 57128189A JP 12818982 A JP12818982 A JP 12818982A JP S636870 B2 JPS636870 B2 JP S636870B2
- Authority
- JP
- Japan
- Prior art keywords
- spot
- laser
- photoelectric drum
- laser beam
- scanning
- 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
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
- G03G15/32—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head
- G03G15/326—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head by application of light, e.g. using a LED array
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
- G03G15/04036—Details of illuminating systems, e.g. lamps, reflectors
- G03G15/04045—Details of illuminating systems, e.g. lamps, reflectors for exposing image information provided otherwise than by directly projecting the original image onto the photoconductive recording material, e.g. digital copiers
- G03G15/04072—Details of illuminating systems, e.g. lamps, reflectors for exposing image information provided otherwise than by directly projecting the original image onto the photoconductive recording material, e.g. digital copiers by laser
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
- G03G15/043—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with means for controlling illumination or exposure
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Dot-Matrix Printers And Others (AREA)
- Laser Beam Printer (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Exposure Or Original Feeding In Electrophotography (AREA)
- Facsimile Scanning Arrangements (AREA)
Description
【発明の詳細な説明】 本発明はレーザプリンタの改良に関する。[Detailed description of the invention] The present invention relates to improvements in laser printers.
コンピユータの出力端末としてのレーザプリン
タ装置は、コンピユータの計算処理時間の高速化
に伴つてより速い印字速度を持つものが要求され
ている。従来のレーザプリンタ装置では高速走査
を行なうために、ポリゴンミラー（多面鏡）を高
速回転する方法がとられているが、これは装置が
大型で重くなり、モータの冷却が必要である等の
欠点があつて、必ずしも取扱いが容易ではない。
これに対し、他の走査手段としてガルバノミラー
が周知であり、小型で取扱いが簡単などの点で有
利である。ガルバノミラーを用いたレーザプリン
タ装置は、例えば特開昭51−117827号公報に提案
されている。 2. Description of the Related Art Laser printer devices used as output terminals for computers are required to have faster printing speeds as calculation processing times of computers become faster. Conventional laser printer devices use a method of rotating polygon mirrors at high speed in order to perform high-speed scanning, but this has disadvantages such as making the device large and heavy and requiring cooling of the motor. It is not always easy to handle.
On the other hand, a galvanometer mirror is well known as another scanning means, and is advantageous in that it is small and easy to handle. A laser printer device using a galvanometer mirror is proposed in, for example, Japanese Patent Laid-Open No. 117827/1983.
しかし、ガルバノミラーで高速走査が可能、か
つ偏向角の大きなものは共振型のものであるが、
これは走査が直線状ではなく正弦波状となり、ス
ポツトの光電ドラム面上の速度が余弦波的に変化
する。従つて、光電ドラム面におけるレーザビー
ムの走査線単位長当りのエネルギーが一様でなく
なり、走査線の両端すなわち光電ドラムの両端で
は過剰、ドラムの中央では不足となり、これが記
録されたドツトの濃淡ムラとなつて現われてしま
う。 However, galvanometer mirrors that can perform high-speed scanning and have a large deflection angle are resonant type mirrors.
In this case, the scanning is not linear but sinusoidal, and the speed of the spot on the photoelectric drum surface changes in a cosinusoidal manner. Therefore, the energy per scanning line unit length of the laser beam on the photoelectric drum surface is no longer uniform, and there is excess energy at both ends of the scanning line, that is, both ends of the photoelectric drum, and an insufficient energy at the center of the drum, which causes uneven density of the recorded dots. It appears like this.
また、記録のためのクロツク周波数が一定であ
ると、上記走査が正弦波的であるため、光電ドラ
ム面の中央と両端とで記録されたドツトの間隔に
ムラができてしまう。本考案は上記の問題点を解
決するためになされたもので、その骨子とする点
は、光電ドラム面上を走査するスポツトの速度、
すなわちガルバノミラー駆動信号を時間で微分
し、これによりレーザの出力強度を変調し、光電
ドラム上の走差線のいかなる部分でも、走査線単
位長当りのエネルギーが一様となつて記録された
ドツトの濃淡ムラがおきないようにし、同時に記
録のためのクロツク周波数を上記微分値によつて
周波数変調し、ドツトが等間隔に記録されるよう
にしたものである。以下、本発明を実施例により
詳細に説明する。 Furthermore, if the clock frequency for recording is constant, the above-mentioned scanning is sinusoidal, resulting in uneven intervals between the dots recorded at the center and both ends of the photoelectric drum surface. The present invention was made to solve the above problems, and its main points are the speed of the spot scanning on the photoelectric drum surface,
That is, by differentiating the galvanometer mirror drive signal with respect to time, and thereby modulating the laser output intensity, the energy per unit length of the scanning line is uniform at any part of the scanning line on the photoelectric drum, and a dot is recorded. At the same time, the clock frequency for recording is frequency-modulated by the differential value, so that dots are recorded at equal intervals. Hereinafter, the present invention will be explained in detail with reference to Examples.
第１図は従来用いられている共振型高速ガルバ
ノミラーの駆動信号を示し、この場合、は正
弦波状に変化する。また第２図は、上記駆動信号
を加えた場合の上記ガルバノミラーによるスポ
ツトの走査状態、すなわち光電ドラム上のスポツ
トの位置を示し、スポツトは光電ドラム上の走査
線の中央部０と両端部A1，A2との間を正弦波状
に走査する。 FIG. 1 shows a drive signal for a conventionally used resonant high-speed galvanometer mirror, in which the signal changes sinusoidally. Furthermore, FIG. 2 shows the scanning state of the spot by the galvano mirror when the above drive signal is applied, that is, the position of the spot on the photoelectric drum. 1 and A 2 in a sinusoidal manner.
ここで、光電ドラム上のスポツト位置をｘ、走
査角周波数をω、振幅をＡとすれば
ｘ＝Ａ sin ωt (1)
で表わされる。よつて、走査線上をスポツトが移
動する速さv0は、
v0＝｜x〓｜
＝ωA｜cos ωt｜ (2)
となり、これを第３図に示す。このように、スポ
ツトの移動速度は走査線の中央部で最も速く、両
端で零となるため、スポツトの強度が一定では記
録されるドツトは中央で薄く、両端で濃くなつて
しまう。よつて本発明においては、スポツトの出
力をその移動速度に応じて変化させる。 Here, if the spot position on the photoelectric drum is x, the scanning angular frequency is ω, and the amplitude is A, then x=A sin ωt (1). Therefore, the speed v 0 at which the spot moves on the scanning line is v 0 =|x〓| =ωA|cos ωt| (2), which is shown in FIG. In this way, the moving speed of the spot is fastest at the center of the scanning line and zero at both ends, so if the intensity of the spot is constant, the recorded dots will be thinner at the center and darker at both ends. Therefore, in the present invention, the output of the spot is changed according to its moving speed.
すなわち、光電ドラム上の走査線の中央部（０
点）で最適状態となるように選ばれたスポツトの
出力をP0とし、
ｐ＝P0｜cos ωt｜ (3)
のように変化する信号ｐによりレーザ出力を変調
する。かくすれば、スポツトの出力はその速さの
変化と同一状態で変化する。このため、光電ドラ
ム上の走査線のいかなる位置においても、スポツ
トから光電ドラム面に与えられる走査線単位長当
りのエネルギーは一定となり、従来のような濃淡
ムラのない、一様な濃度の記録を得ることができ
る。 In other words, the central part (0) of the scanning line on the photoelectric drum
Let P 0 be the output of the spot selected to achieve the optimum state at point ), and the laser output is modulated by a signal p that changes as p=P 0 |cos ωt| (3). Thus, the output of the spot changes in the same manner as its velocity changes. Therefore, at any position of the scanning line on the photoelectric drum, the energy per unit length of the scanning line applied from the spot to the photoelectric drum surface is constant, making it possible to record uniform density without uneven shading as in the past. Obtainable.
また、従来のように一定のクロツク周波数でレ
ーザ出力を変調した場合は、本来等間隔に記録さ
れるべきドツトが第４図のようになり、中央で
疎、両端で密になつて、記録に正弦波的な偏りが
生じてしまう。よつて、前記スポツト出力の場合
と同様に、クロツク周波数を前記(3)式に従つて周
波数変調すれば、ドツトの記録速度は従来のよう
に一定ではなく、スポツトの移動速度に対応して
変化するため、走査線の中央、両端にかかわら
ず、第５図に示すようにドツトの間隔は一定とな
る。 Furthermore, when the laser output is modulated at a constant clock frequency as in the past, the dots that should normally be recorded at equal intervals become as shown in Figure 4, with the dots becoming sparse in the center and dense at both ends. A sinusoidal deviation will occur. Therefore, as in the case of spot output, if the clock frequency is frequency modulated according to equation (3) above, the dot recording speed will not be constant as in the conventional case, but will change in accordance with the moving speed of the spot. Therefore, the dot spacing is constant as shown in FIG. 5, regardless of whether it is in the center or at both ends of the scanning line.
第６図は光源として気体レーザを用いた場合の
本発明の構成例を示し、気体レーザ１から送出さ
れたレーザビームは音響―光変調器２を通り、絞
り込みレンズ３を経てガルバノミラー４に投射さ
れ、反射されて光電ドラム５上を走査する。 FIG. 6 shows a configuration example of the present invention when a gas laser is used as a light source. The laser beam sent out from the gas laser 1 passes through an acousto-optic modulator 2, passes through a focusing lens 3, and is projected onto a galvanometer mirror 4. is reflected and scanned on the photoelectric drum 5.
光電ドラム５は駆動装置（図示せず）により図
示のように反時計方向に回転し、その表面は帯電
器６によつて一様に帯電した状態となる。これを
レーザビームが走査するため、光電ドラム５は表
面に電荷による潜像が生じ、さらに回転して現像
器７により現像されて像が現われる。この像は転
写器８で記録紙９に転写され、さらに定着器１０
で加熱、定着される。 The photoelectric drum 5 is rotated counterclockwise as shown by a drive device (not shown), and its surface is uniformly charged by a charger 6. Since this is scanned by a laser beam, a latent image due to electric charge is generated on the surface of the photoelectric drum 5, which is further rotated and developed by a developing device 7, so that an image appears. This image is transferred to a recording paper 9 by a transfer device 8, and further by a fixing device 10.
is heated and fixed.
ここで、ガルバノミラー４は駆動回路１１から
加えられた駆動信号（すなわち、第１図における
駆動信号）により高速共振し、レーザビームは
光電ドラム５上を走査する一方、駆動回路１１の
出力は微分器１２に加えられ、微分されると共に
整流されて第３図に示した波形の出力となつて光
変調器駆動回路１３に加わり、後述するクロツク
周波数を振幅変調して光変調器２に加え、レーザ
ビームを変調する。なお、上記微分器１２の微
分、整流出力はクロツク発生器１４に加わり、ク
ロツク周波数を周波数変調する。すなわち、光変
調器２に加わるクロツク周波数は従来のように一
定周波数ではなく、スポツトの光電ドラム面上の
走査速度に対応して周波数変調されたものであ
り、このため、スポツトは第５図に示したように
等間隔のドツトとして記録され、かつスポツトの
強度はその走査速度に対応して変化しているた
め、走査線上のドツトの濃度はムラがなく、一様
な濃度で記録される。 Here, the galvanometer mirror 4 resonates at high speed due to the drive signal applied from the drive circuit 11 (that is, the drive signal in FIG. 1), and the laser beam scans the photoelectric drum 5, while the output of the drive circuit 11 is differentiated. 12, is differentiated and rectified, becomes an output with the waveform shown in FIG. Modulate the laser beam. The differentiated and rectified output of the differentiator 12 is applied to a clock generator 14 to frequency modulate the clock frequency. That is, the clock frequency applied to the optical modulator 2 is not a constant frequency as in the conventional case, but is frequency modulated corresponding to the scanning speed of the spot on the photoelectric drum surface. As shown, the dots are recorded as equally spaced dots, and the intensity of the spots changes in accordance with the scanning speed, so the density of the dots on the scanning line is even and uniform.
この場合、光源として用いた気体レーザ１は常
に一定出力のレーザビームを送出し、これを外部
の光変調器２で変調するものとしたが、第７図に
光源として半導体レーザを用い、その電源を変調
することにより、光変調器を用いることなく、レ
ーザ光を直接変調した場合の構成例を示す。同図
において、微分器１２およびクロツク発生器１４
の各出力はレーザ駆動回路１５に加えられ、これ
より変調された直流出力が半導体レーザ１６に加
わり、変調されたレーザビームが送出される。そ
の他の部分の構成および動作は第６図の場合と同
様である。 In this case, the gas laser 1 used as a light source always sends out a laser beam with a constant output, and this is modulated by an external optical modulator 2. In Fig. 7, a semiconductor laser is used as a light source, and its power source is An example of a configuration in which laser light is directly modulated without using an optical modulator by modulating is shown below. In the figure, a differentiator 12 and a clock generator 14
The respective outputs are applied to a laser drive circuit 15, from which a modulated DC output is applied to a semiconductor laser 16, and a modulated laser beam is sent out. The configuration and operation of other parts are the same as in the case of FIG. 6.
以上説明したように、本発明によるときは濃淡
ムラのない、間隔の一様なドツトよりなる記録像
を得ることができ、その効果は大きいものであ
る。 As explained above, according to the present invention, it is possible to obtain a recorded image consisting of dots with uniform intervals without unevenness in density, and the effect is great.
第１図はガルバノミラー駆動信号の波形図、第
２図は光電ドラム上のレーザビームのスポツトの
位置を示す波形図、第３図は同じくスポツトの速
さを示す波形図、第４図は従来の装置において、
記録が走査線の中央と両端とで密と疎になる状態
を示す説明図、第５図は本発明によりスポツトが
常に一様な間隔で記録される状態を示す説明図、
第６図および第７図は光源に気体レーザおよび半
導体レーザを用いた場合の各構成例を示す説明図
である。
１……気体レーザ、２……光変調器、４……ガ
ルバノミラー、５……光電ドラム、１１……ガル
バノミラー駆動回路、１２……微分器、１３……
光変調器駆動回路、１４……クロツク発生器、１
５……レーザ駆動回路、１６……半導体レーザ。
Figure 1 is a waveform diagram of the galvanometer mirror drive signal, Figure 2 is a waveform diagram showing the position of the laser beam spot on the photoelectric drum, Figure 3 is a waveform diagram showing the speed of the spot, and Figure 4 is the conventional waveform diagram. In the device of
FIG. 5 is an explanatory diagram showing a state in which recording becomes denser and sparser at the center and both ends of a scanning line; FIG. 5 is an explanatory diagram showing a state in which spots are always recorded at uniform intervals according to the present invention;
FIG. 6 and FIG. 7 are explanatory diagrams showing respective configuration examples when a gas laser and a semiconductor laser are used as the light source. DESCRIPTION OF SYMBOLS 1... Gas laser, 2... Optical modulator, 4... Galvano mirror, 5... Photoelectric drum, 11... Galvano mirror drive circuit, 12... Differentiator, 13...
Optical modulator drive circuit, 14... clock generator, 1
5... Laser drive circuit, 16... Semiconductor laser.
Claims (1)
して絞り込み、該レザーザ光をガルバノミラーに
より偏向せしめて上記光電ドラム面上を走査する
レーザプリンタ装置において、上記光電ドラム面
上における上記スポツトの走査速度の大きさに比
例するように上記ガルバノミラーの駆動信号を微
分した信号により上記レーザ光の強度を変調する
手段と、上記スポツトを記録する基本クロツク周
波数を上記スポツトの走査速度の大きさに比例す
るように上記ガルバノミラーの駆動信号を微分し
た信号により周波数変調する手段とを具備するこ
とを特徴とするレーザプリンタ装置。1. In a laser printer device that focuses a laser beam onto a photoelectric drum surface as a minute spot and scans the photoelectric drum surface by deflecting the laser beam with a galvano mirror, the scanning speed of the spot on the photoelectric drum surface is means for modulating the intensity of the laser beam by a signal obtained by differentiating the drive signal of the galvanometer mirror so as to be proportional to the scanning speed of the spot; A laser printer device comprising means for frequency modulating a signal obtained by differentiating the drive signal for the galvano mirror.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57128189A JPS5849963A (en) | 1982-07-21 | 1982-07-21 | Laser printer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57128189A JPS5849963A (en) | 1982-07-21 | 1982-07-21 | Laser printer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5849963A JPS5849963A (en) | 1983-03-24 |
| JPS636870B2 true JPS636870B2 (en) | 1988-02-12 |
Family
ID=14978641
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57128189A Granted JPS5849963A (en) | 1982-07-21 | 1982-07-21 | Laser printer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5849963A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01308691A (en) * | 1988-06-07 | 1989-12-13 | Daimatsu Kagaku Kogyo Kk | Post card and manufacture thereof |
| JPH0377671U (en) * | 1989-11-30 | 1991-08-05 | ||
| JPH0377670U (en) * | 1989-11-30 | 1991-08-05 | ||
| JPH04207267A (en) * | 1990-11-28 | 1992-07-29 | Challange Five:Kk | Shielding sheet of information recording paper, such as recording paper for facsimile and method for shielding information recording paper by using the shielding sheet |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03366Y2 (en) * | 1985-04-19 | 1991-01-09 | ||
| JPS61256321A (en) * | 1985-05-10 | 1986-11-13 | Hitachi Ltd | LCD projection display device |
| JP2669531B2 (en) * | 1988-04-27 | 1997-10-29 | 富士写真フイルム株式会社 | Light beam recording device |
| US6493019B1 (en) * | 1999-01-29 | 2002-12-10 | Canon Kabushiki Kaisha | Image forming apparatus |
| JP2005308865A (en) * | 2004-04-19 | 2005-11-04 | Brother Ind Ltd | Light output signal output device |
| JP4639973B2 (en) * | 2005-06-07 | 2011-02-23 | カシオ計算機株式会社 | Image projection device |
| US9188846B2 (en) | 2011-02-18 | 2015-11-17 | Nec Corporation | Scanning-type image display device and its image display method |
-
1982
- 1982-07-21 JP JP57128189A patent/JPS5849963A/en active Granted
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01308691A (en) * | 1988-06-07 | 1989-12-13 | Daimatsu Kagaku Kogyo Kk | Post card and manufacture thereof |
| JPH0377671U (en) * | 1989-11-30 | 1991-08-05 | ||
| JPH0377670U (en) * | 1989-11-30 | 1991-08-05 | ||
| JPH04207267A (en) * | 1990-11-28 | 1992-07-29 | Challange Five:Kk | Shielding sheet of information recording paper, such as recording paper for facsimile and method for shielding information recording paper by using the shielding sheet |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5849963A (en) | 1983-03-24 |
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