JPH10268215A - Multi-laser optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate delay of throughput and the transmission of unnecessary image transfer data and to excellently record image information with multiple resolution by properly setting the refracting power of a collimator lens, the irradiated surface angles of multiple lasers, etc. SOLUTION: A CPU 114 after setting a mode of selected arbitrary resolution sends a laser DRV signal out to a laser unit 107, and the multiple lasers which are actuated corresponding to the selected resolution emit lights to irradiate mirror surfaces of a polygon mirror 117. After the rotational frequency of the polygon mirror 117 becomes stable, the laser lights deflected by the polygon mirror 117 are guided to different areas on a photosensitive drum surface 106 through a return mirror 105. Then the photosensitive drum surface 106 is optically scanned with the laser lights at intervals of the selected resolution to record image information on the photosensitive drum surface 106 as a recording medium with the selected desired resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-laser optical device, and more particularly to a plurality of resolutions when forming an image on a predetermined surface by using a laser beam. The present invention relates to a multi-laser optical device suitable for an apparatus such as a laser copying machine or a laser beam printer (LBP) in which image information can be recorded at a desired resolution by switching to an arbitrary resolution selected from the above. Things.

[0002]

2. Description of the Related Art Conventionally, in a multi-laser optical device equipped with a multi-laser, a plurality of laser beams emitted from the multi-laser are incident on a deflection surface of an optical deflector via an optical element such as a collimator lens. A plurality of laser beams deflected and reflected by the deflecting surface of the optical deflector are guided to different regions on the surface to be scanned through a scanning lens (fθ lens), and the plurality of laser beams are passed through the surface to be scanned. An image is formed by light scanning simultaneously with light.

On the other hand, the rotational angular velocity of a light deflector (polygon mirror) is controlled by using a plurality of laser light sources and controlling the angles of the traveling directions of the individual laser lights emitted from the plurality of laser light sources. A multi-laser optical device capable of performing high-speed scanning recording without hastening has been proposed in, for example, Japanese Patent Application Laid-Open No. 58-68016.

[0004]

However, when an output image is obtained by using the above-mentioned multi-laser optical device and switching to, for example, an arbitrary resolution among a plurality of resolutions,
In the multi-laser optical device, since each laser light source or light-emitting point is not necessarily arranged at intervals corresponding to an arbitrary resolution, it is necessary to thin out in the sub-scanning direction. Processing amount) is delayed, or extra image transfer data (blank data) is sent.

According to the present invention, when recording image information by switching to an arbitrary resolution selected from a plurality of resolutions, the refracting power of each collimator lens constituting the multi-laser unit or the power of each multi-laser By appropriately setting the irradiation surface angle and the like, image information can be recorded at a plurality of resolutions without delaying the throughput of the entire apparatus, which has been a problem in the past, and transmitting unnecessary image transfer data. It is an object of the present invention to provide a multi-laser optical device that can perform well.

[0006]

A multi-laser optical device according to the present invention comprises: (1) a multi-laser in which a plurality of light emitting points are juxtaposed in a sub-scanning direction, and a collimator lens provided corresponding to the multi-laser. The optical means is arranged in correspondence with a plurality of resolutions in the sub-scanning direction, and a plurality of laser beams are emitted from the optical means corresponding to an arbitrary selected one of the plurality of resolutions and guided to an optical deflector. A plurality of laser beams deflected by the optical deflector, guided to different regions on the surface to be scanned through the imaging means, and simultaneously scanned on the surface to be scanned by the plurality of laser beams. A laser optical device,
The multi-laser of each optical means is composed of the same multi-laser arranged on the same plane, and the refractive power of the collimator lens of each optical means in the sub-scanning direction is set according to the corresponding resolution. It is characterized by:

In particular, (1-1) the refractive power in the sub-scanning direction of the collimator lens of each of the optical means corresponds to the scanning line interval in the sub-scanning direction of a plurality of laser beams exposed on the surface to be scanned. It is characterized in that it is set so as to have an interval of the resolution to be changed.

(2) Optical means having a multi-laser in which a plurality of light-emitting points are juxtaposed in the sub-scanning direction and a collimator lens provided corresponding to the multi-laser are provided for each of a plurality of resolutions in the sub-scanning direction. Arranged in correspondence with each other, a plurality of laser beams are emitted from optical means corresponding to an arbitrary resolution selected from the plurality of resolutions, guided to an optical deflector, and a plurality of lasers deflected by the optical deflector. A multi-laser optical device that guides light to different regions on a surface to be scanned through an image forming means, and simultaneously scans the surface to be scanned with the plurality of laser beams, wherein a collimator of each optical means is provided. The refracting power of the meter lens in the sub-scanning direction is the same as each other, and the multi-laser of each optical means is composed of the same multi-laser. It is characterized by being parallel or inclined with respect to the entrance plane of the lens.

In particular, (2-1) the irradiation surface of each multi-laser parallel or inclined with respect to the incident surface of the corresponding collimator lens in the sub-scanning section has a plurality of surfaces exposed on the surface to be scanned. Are attached so that the scanning line interval in the sub-scanning direction of the laser beam becomes the interval of the corresponding resolution.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram (configuration diagram) of a main part of a first embodiment of the present invention. FIG. 2 is a side view (sub-scan sectional view) of a main part when a part of FIG. 1 is viewed from the side. still,
The configuration diagram of the present apparatus shown in FIG. 1 can be similarly applied to a second embodiment described later.

In FIG. 1 and FIG. 2, reference numeral 107 denotes a multi-laser unit, and optical means 107a, 107b, and 10 are arranged corresponding to a plurality of resolutions in the sub-scanning direction.
7c (three in this embodiment), and each of the optical means 107a, 107b, 107c is a multi-laser 121a, 121b in which a plurality of light emitting points (laser diodes) are juxtaposed at a predetermined interval in the sub-scanning direction. , 121c and collimator lenses 120a, 120b, 120 provided corresponding to the multi-lasers 121a, 121b, 121c.
c.

Each optical means 107 in the present embodiment
a, 107b, 107c
Reference numerals 1b and 121c denote the same multi-lasers arranged on the same plane, and their emission surfaces (irradiation surfaces) have the corresponding collimator lenses 120a, 120b, and 1 in the sub-scanning cross section.
It is attached so as to be parallel to the incident surface of 20c.

Further, each optical means 1 in the present embodiment.
07a, 107b, 107c collimator lens 12
0a, 120b, and 120c in the sub-scanning direction are set in accordance with the corresponding resolution, and the refractive power is determined by the scanning line interval (beam) in the sub-scanning direction of a plurality of laser beams exposed on the surface to be scanned. (Interval) is set to be the interval of the corresponding resolution.

In the present embodiment, the optical means 107a uses
The configuration is such that an image with a resolution of 480 DPI can be obtained with the optical unit 107b, and an image with a resolution of 400 DPI can be obtained with the optical unit 107c.

Reference numeral 117 denotes an optical deflector, which comprises, for example, a polygon mirror (rotating polygon mirror) and is rotated at a constant speed in the direction of arrow A by a driving means such as a DC scanner motor 101 or the like. Reference numeral 110 denotes an imaging unit (fθ lens) having a condensing function and fθ characteristics, which has a spherical lens 102 and a toric lens 103, and is based on image information deflected and reflected by the deflecting surface of the optical deflector 117. A plurality of laser beams are focused on different areas on the photosensitive drum surface 106 as a surface to be scanned, and the tilt of the deflecting surface of the optical deflector 117 is corrected. A folding mirror 105 reflects a plurality of laser beams passing through the fθ lens 110 toward the photosensitive drum surface 106 side. Reference numeral 104 denotes a horizontal synchronization detection mirror (BD mirror), which reflects a laser beam for detecting a writing synchronization signal for adjusting a scanning start position on the photosensitive drum surface 106 to a beam detector (BD sensor) 108 side. Reference numeral 113 denotes an A / D converter, and reference numeral 114 denotes a CPU (Central Processing Unit), which sets, for example, a mode of an arbitrary resolution selected from a plurality of resolutions.

Next, the operation of this embodiment will be described with reference to FIGS.
It will be described based on.

In this embodiment, the CPU 114 sets a mode of an arbitrary resolution selected from a plurality of resolutions, sends a laser DRV signal to the laser unit 107, and outputs a multi-laser (book) corresponding to the selected resolution. In the embodiment, one of three multi lasers is activated (O
N). A plurality of laser beams are emitted from the activated multi-laser, and irradiate the mirror surface (deflection surface) of the polygon mirror 117. Then, the CPU 114 rotates the DC scanner motor 101 to turn on the motor drive signal, and the CPU 114 determines that the status signal RDY from the DC scanner motor 101 indicating transition from the start area to the control area is enabled, that is, is in the “H” state. After the rotation of the polygon mirror 117 is stabilized, the plurality of laser beams deflected by the polygon mirror 117 are transmitted to the fθ lens 11.
0, the photosensitive drum surface 1 via the return mirror 105
06 to different areas on the same. And the photosensitive drum surface 1
At the same time, optical information is scanned on the photosensitive drum surface 106 as a recording medium by performing optical scanning on the optical disc 06 at intervals of a resolution selected by a plurality of laser beams.

As described above, in this embodiment, as described above, the optical means 107 arranged corresponding to a plurality of resolutions respectively.
a, 107b, 107c collimator lens 120
By appropriately setting the refracting powers in the sub-scanning directions a, 120b, and 120c according to the corresponding resolution, the throughput in the entire apparatus, which has conventionally been a problem, is not delayed, and unnecessary image transmission data is transmitted. , Image information can be recorded at a plurality of resolutions.

The resolution in the main scanning direction can be switched by, for example, changing the light emission interval of laser light, that is, the image clock frequency.

FIG. 3 is a side view (sub-scan sectional view) of a main part of a part of the second embodiment of the present invention. In the figure, the same elements as those shown in FIG. 2 are denoted by the same reference numerals.

The present embodiment differs from the first embodiment in that the collimator lenses of the optical means arranged in correspondence with a plurality of resolutions have the same refracting power in the sub-scanning direction. That is, the irradiation surface (emission surface) of the multi-laser is attached in such a manner as to be parallel or inclined at an angle to the incident surface of the corresponding collimator lens in the sub-scanning cross section in accordance with the corresponding resolution. Other configurations and optical functions are substantially the same as those of the first embodiment, and thus the same effects are obtained.

That is, in the figure, reference numeral 137 denotes a multi-laser unit having optical means 137a, 137b and 137c (three in this embodiment) arranged corresponding to a plurality of resolutions, respectively. Optical means 137
Reference numerals a, 137b, and 137c denote multi-lasers 131a, 131b, and 131c in which a plurality of light emitting points (laser diodes) are juxtaposed at predetermined intervals in the sub-scanning direction, and collimators provided corresponding to the multi-lasers 131a, 131b, and 131c. It has lenses 130a, 130b, and 130c.

Each optical means 137 in this embodiment
a, 137b, 137c collimator lens 130
a, 130b, and 130c have the same refractive power in the sub-scanning direction, and have respective optical units 137a, 137b, and 13c.
The irradiation surface of the multi-lasers 131a, 131b, 131c of 7c is attached parallel to or inclined at an angle to the incident surface of the corresponding collimator lens 130a, 130b, 130c in the sub-scanning cross section according to the corresponding resolution. ing. Thus, in the present embodiment, the scanning line interval (beam interval) in the sub-scanning direction of the plurality of laser beams exposed on the surface to be scanned is set to the corresponding resolution interval.

In this embodiment, as shown in FIG.
When obtaining an image of 0 DPI, the irradiation surface of the multi-laser is attached parallel to the incident surface of the corresponding collimator lens in the sub-scanning section, and 480 DPI, 600 D
As the PI and the high-resolution image are obtained, the inclination angle of the irradiation surface of the multi-laser is made larger with respect to the incident surface of the corresponding collimator lens.

Next, the operation of this embodiment will be described with reference to FIGS.
It will be described based on.

In this embodiment, the CPU 114 sets a mode of an arbitrary resolution selected from a plurality of resolutions, sends a laser DRV signal to the laser unit 107, and outputs a multi-laser (final) laser corresponding to the selected resolution. In the embodiment, one of three multi lasers is activated (O
N). A plurality of laser beams are emitted from the activated multi-laser, and irradiate the mirror surface (deflection surface) of the polygon mirror 117. Then, the DC scanner motor 101 is turned on to turn on the motor drive signal, and the DC scanner motor 101 representing the transition from the start area to the control area.
Is enabled, that is, "
The CPU 114 detects that the state is “H”, and after the rotation speed of the polygon mirror 117 is stabilized, the plurality of laser beams deflected by the polygon mirror 117 are transmitted to the fθ lens 1.
10 guides light to different areas on the photosensitive drum surface 106 via the turning mirror 105. Then, the image information is recorded at the desired resolution selected on the photosensitive drum surface 106 as a recording medium by simultaneously performing optical scanning on the photosensitive drum surface 106 with a plurality of laser beams at intervals of the selected resolution.

As described above, in the present embodiment, as described above, the optical means 137 arranged corresponding to a plurality of resolutions respectively.
a, 137b, 137c collimator lens 130
a, 130b, and 130c have the same refracting power in the sub-scanning direction, and the respective optical means 137a, 137b, and 137
By inclining the irradiation surface of the multi-lasers 131a, 131b, 131c of c in the sub-scanning cross section with respect to the incident surfaces of the corresponding collimator lenses 130a, 130b, 130c in accordance with the corresponding resolution, at an angle or at an angle. In addition, image information can be recorded at a plurality of resolutions without delaying the throughput of the entire apparatus, which has conventionally been a problem, and without transmitting unnecessary image transfer data.

In each of the first and second embodiments, a multi-laser unit is constituted by three optical means corresponding to each resolution (400 DPI, 480 DPI, 600 DPI). However, the present invention is not limited to this. The number of optical means may be set according to the number (type) of required resolutions.

[0029]

According to the present invention, when recording image information by switching to an arbitrary resolution selected from a plurality of resolutions as described above, the refractive power of each collimator lens constituting the multi-laser unit Alternatively, by appropriately setting the irradiation surface angle or the like of each multi-laser, the throughput of the entire apparatus, which has been a problem in the past, is not delayed, and a plurality of unnecessary image transfer data are not transmitted. Thus, a multi-laser optical device capable of satisfactorily recording image information at a resolution of 1 mm can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part of a first embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of a part of the first embodiment of the present invention.

FIG. 3 is an enlarged explanatory view of a part of Embodiment 2 of the present invention.

DESCRIPTION OF SYMBOLS 101 DC scanner motor 110 Image forming means 102 Spherical lens 103 Toric lens 104 Horizontal synchronization detecting mirror 105 Folding mirror 106 Scanned surface (photosensitive drum surface) 107, 137 Multi laser unit 107a, 107b, 107c Optical means 137a , 137b, 137c Optical means 108 Beam detector for horizontal synchronization detection 113 A / D converter 114 CPU 117 Optical deflector (polygon mirror)

Claims (4)

[Claims] 1. An optical unit having a multi-laser in which a plurality of light emitting points are juxtaposed in a sub-scanning direction and a collimator lens provided corresponding to the multi-laser is provided for each of a plurality of resolutions in the sub-scanning direction. A plurality of laser beams emitted from optical means corresponding to an arbitrary resolution selected from the plurality of resolutions, guided to an optical deflector, and a plurality of laser beams deflected by the optical deflector. A multi-laser optical device that guides light to different regions on the surface to be scanned through the imaging means, and simultaneously scans the surface to be scanned with the plurality of laser beams, Is composed of the same multi-laser arranged on the same plane, and the refractive power of the collimator lens of each optical means in the sub-scanning direction is set according to the corresponding resolution. Apparatus. 2. A refracting power in a sub-scanning direction of a collimator lens of each of the optical means is a resolution interval corresponding to a scanning line interval in the sub-scanning direction of a plurality of laser beams exposed on the surface to be scanned. 2. The multi-laser optical device according to claim 1, wherein: 3. An optical unit having a multi-laser in which a plurality of light emitting points are juxtaposed in the sub-scanning direction and a collimator lens provided corresponding to the multi-laser is provided for each of a plurality of resolutions in the sub-scanning direction. A plurality of laser beams emitted from optical means corresponding to an arbitrary resolution selected from the plurality of resolutions, guided to an optical deflector, and a plurality of laser beams deflected by the optical deflector. A multi-laser optical device that guides light to different areas on the surface to be scanned through the imaging means, and simultaneously scans the surface to be scanned with the plurality of laser beams, wherein the collimator of each of the optical means The refracting power of the lens in the sub-scanning direction is the same as each other, and the multi-laser of each optical means comprises the same multi-laser, and the irradiation surface thereof corresponds to the corresponding collimator lens in the sub-scanning cross section according to the corresponding resolution. Multi-laser optical apparatus characterized by being parallel to or inclined with respect to the incident surface. 4. An irradiation surface of each multi-laser parallel or inclined with respect to an incident surface of a corresponding collimator lens in the sub-scanning cross section includes a plurality of laser beams exposed on the surface to be scanned. 4. The multi-laser optical device according to claim 3, wherein the scanning lines are mounted so that the scanning line intervals in the sub-scanning direction have the corresponding resolution intervals.