JPH0648845B2 - Optical beam scanning device using rotating polygon mirror - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light beam scanning device, and more specifically, to a rotation monitoring structure for a rotary polygon mirror in a light beam scanning device using a rotary polygon mirror as a light beam scanning means. Regarding the improvement of.

(Background of the Invention) One type of light beam scanning device is an image output device that reflects a light beam from a light source by a rotating polygon mirror and applies the light beam to a photoconductor through a condenser lens.

FIG. 7 is a block diagram showing an example of a conventional image output device. In FIG. 7, reference numeral 1 is, for example, a He—Ne laser light source. The output beam of the light source 1 includes a shutter 2, a mirror 3, a pinhole 4, a mirror 5, and an acousto-optical modulator.
ooptic modulator; abbreviated as AOM below) Lens 6 → AO
M7 → neutral density (hereinafter abbreviated as ND) filter 8 → AOM lens 9 → beam expander (hereinafter abbreviated as BE) unit 11 → mirror 12 → pinhole 13 → cylindrical lens; hereinafter CL Abbreviated) 14 → C
It is incident on the rotary polygon mirror 18 via an optical system composed of L15 → mirror 16 → mirror 17, and is reflected as a scanning light beam. The scanning light beam reflected by the polygon mirror 18 is applied to the roll-shaped photosensitive member 21 via a condenser lens 19 using an fθ lens and CL20. A mirror 22 is arranged near the scanning end of the photoconductor 21, and the scanning light beam reflected by the mirror 22 is incident on a light receiving element 23 arranged on the substantially same plane as the photoconductor 21. The light receiving element 23 outputs a horizontal synchronizing signal. In addition, in the vicinity of the rotary polygon mirror 18,
A surface detection sensor 24 for detecting the reflecting surface of the rotary polygon mirror 18 is provided.

Here, the shutter 2 is closed in the non-printing state and opened in the printing state. Also, the photoconductor 21 opens the shutter 2 and
Even if the 0th-order light output with the OM7 turned off is received at the same place for a long time, the light-receiving element 23 is exposed to the light.
It does not respond at the next light output. That is, it is necessary to turn on the AOM 7 in order to obtain the horizontal synchronizing signal from the light receiving element 23.

FIG. 8 is a timing chart for explaining the printing operation of the apparatus configured as described above. In FIG.
(A) shows the output of the surface detection sensor 24, (b) shows the output of the light receiving element 23, and (c) shows the output of the AOM 7. In the initial state, the AOM 7 is off, but it turns on according to the first output of the surface detection sensor 24. As a result, the light receiving element 23 outputs a horizontal synchronizing signal. Then, print data for modulation is added to the AOM 7 according to the horizontal synchronizing signal, and the photoconductor 21 is exposed to the scanning light beam modulated by the print data.

(Problems to be Solved by the Invention) However, according to such a conventional configuration, fog does not occur due to the photosensitive member 21 receiving the 0th order light of the scanning light beam at the same place for a long time during non-printing. In addition, the scanning light beam must be completely blocked. Therefore, it is impossible to obtain the horizontal synchronizing signal from the light receiving element 23. or,
It is not possible to monitor the rotating operation of the rotary polygon mirror 18 in this non-printing state.

Therefore, in the conventional device, the surface detection sensor 24 is arranged to monitor the rotation of the rotary polygon mirror 18, but the surface detection sensor 24 is arranged around the rotary polygon mirror 18 as the number of parts increases. Space must be secured, and the structure is complicated. Further, there is also a problem that the photoreceptor 21 projects toward the CL 20 side during loading, which causes a jam.

The present invention has been made in view of the above points, and an object of the present invention is to easily monitor the rotating operation of a rotary polygonal mirror even during non-printing without increasing the number of parts and to cause a jam during loading. It is to realize a light beam scanning device using a rotating polygon mirror capable of preventing the above problem.

(Means for Solving the Problems) The present invention which solves the above-mentioned problems is a light beam scanning device which reflects a light beam from a light source by a rotating polygon mirror and gives it to a photoconductor through a condenser lens. A shutter for opening and closing the scanning light beam is provided on the front surface of the photoconductor, and the shutter is used as a part of a conveyance guide of the photoconductor at the time of loading.

(Operation) According to the light beam scanning device of the present invention, the horizontal synchronizing signal is obtained from the light receiving element in the vicinity of the scanning end even during non-printing, and the shutter guides the photoconductor during loading.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

1 and 2 are block diagrams showing an embodiment of the present invention. In these figures, 25 is a He-Ne laser light source similar to the light source of FIG. The output beam of the light source 25 is an ND filter 26 → AOM lens 27 → AOM 28.
→ mirror 29 → BE 30 → pinhole 31 → CL 32 →
The light enters the rotary polygon mirror 37 through an optical system composed of a mirror 34, a BE 35, and a mirror 36, and is reflected as a scanning light beam. The scanning light beam reflected by the rotating polygon mirror 37 is
The light enters the photoconductor 41 through the condenser lens 38 including the fθ lens, the CL 39, and the shutter 40. On the other hand, CL3
A mirror 42 is provided near the scanning end between the shutter 9 and the shutter 40.
The scanning light beam reflected by the mirror 42 is incident on the light receiving element 44 via the mirror 43. still,
The light receiving element 44 outputs a horizontal synchronizing signal similarly to the light receiving element 23 of FIG.

Reference numeral 51 is a supply magazine in which the unexposed photoconductor 41 is housed. Reference numeral 52 denotes a paper end sensor for detecting the end of the photoconductor 41, which is arranged near the output of the supply magazine 51. Reference numerals 53 and 54 denote loading rollers that pull out the unexposed photoconductor 41 stored in the supply magazine 51 and send it to the photosensitive recording unit side. The loading rollers 53 and 54 are connected to a loading motor 55 via a one-way clutch (not shown). An auto cutter 56 automatically cuts the photoconductor 41 in accordance with a command signal, and is arranged downstream of the loading roller 53. A cutter sensor for controlling the reciprocating motion of the blade of the auto cutter 56 is provided at both ends of the auto cutter 56, but it is not shown. Reference numeral 57 is a turn roller that bends the conveyance direction of the photoconductor 41 delivered through the loading roller 54 at a substantially right angle. A jam sensor 58 is arranged near the turn roller 57. Reference numeral 59 is a media path sensor which is arranged on the upstream side of the photosensitive recording section and detects the presence or absence of the photoconductor 41. Reference numeral 60 denotes a main roller which is arranged in the vicinity of the photosensitive section and which feeds the photosensitive body 41 which has been subjected to the photosensitive recording to the winding magazine 61 side. The main roller 60 is rotationally driven by a main motor 66. 6
A loading sensor 2 is provided downstream of the main roller 60 and detects the presence or absence of the photoconductor 41. A manual cutter 63 that cuts the photoconductor 41 by a manual operation is disposed between the loading sensor 62 and the winding magazine 61. In the winding magazine 61, as described above, the photoconductor 41 on which the photosensitive recording has been completed is wound and stored. A winding sensor 64 is arranged near the winding shaft of the winding magazine 61. Further, the take-up magazine 61 is detachably arranged at a predetermined position, and the detached state is detected by the magazine sensor 65. 68 is a part of the conveyance guide,
It is connected to the shutter 40. The shutter 40 is in the position shown by the solid line in FIG. 1 at the time of loading and also functions as a part of the conveyance guide, and at the position shown by the broken line during printing, it enables exposure. The shutter 40 may be moved by any means, for example, by a motor or the like via a link or the like.

FIG. 3 is a diagram showing only the main part of the electrical configuration of the above-mentioned embodiment, and the parts corresponding to those of FIGS. 1 and 2 are designated by the same reference numerals. In the figure, 67 is a control unit that performs various controls, and is configured by a microcomputer or the like. This control unit 67
Is a paper end sensor 52 and a media path sensor 5
9, receiving signals from the loading sensor 62 and the like, the loading motor 55, the main motor 66, the shutter 16
Drive control is performed.

Next, the operation of the embodiment thus configured will be described.

FIG. 4 is a timing chart for explaining the operation of the above embodiment. In FIG. 4, (a) represents ON / OFF of the loading motor 55, (b) represents the rotation speed state of the loading motor 55, (c) represents ON / OFF of the main motor 66, and (d). Is the end sensor 5
2 shows the detection signal of No. 2 and (e) is the media path sensor 5
9 represents a detection signal of the loading sensor 6 and FIG.
2 represents the detection signal.

First, when the loading start switch of the photoconductor 41 is pressed at time t ₁ after the supply magazine 51 is set, the control unit 67 causes the loading motor 5 to be loaded.
5 is started in a high speed rotation state. As a result, the unexposed photoconductor 41 is pulled out from the supply magazine 51 at high speed. The photoconductor 41 pulled out from the supply magazine 51 passes through the turn roller 57 and the media path sensor 5
When it reaches 9 (time t ₂ ), the media path sensor 59
Detects the photoconductor 41, the detection signal of the media path sensor 59 becomes L (low) level. When the detection signal of the media path sensor 59 becomes L level, the control unit 6
7, the rotation speed of the loading motor 55 is switched to a low speed, and the loading motor 55 in the low speed rotation state starts the main motor 66 at a rotation speed that is a little higher than the transfer speed, and the main roller 60 is rotated. Rotate. The speed of the loading motor 55 can be switched by controlling the drive pulse of the DC motor, for example. In this state, when the photoconductor 41 is guided to the main roller 60 by being guided by the transport guide 68 and the shutter 40, the photoconductor 41 is delivered toward the take-up magazine 61 at the transport speed of the main roller 60. Here, since the loading rollers 53 and 54 are connected to the loading motor 55 via the one-way clutch, the loading rollers 53 and 54 do not adversely affect the transport operation of the photoconductor 41, and the photoconductor 41 is By the time the main roller 60 reaches the main roller 60, the main roller 60 has already rotated at a speed at which it can be conveyed at a higher speed than the loading rollers 53 and 54, and therefore the slack in the photoconductor 41 does not occur. The photoconductor 41 sent out from the main roller 60 moves at time t ₃
When the loading sensor 62 is reached, the loading sensor 62 detects the photoconductor 41, and the detection signal of the loading sensor 62 becomes L level. When the detection signal of the loading sensor 62 becomes L level,
The rotation of the loading motor 55 is stopped by the control unit 67. Then, at time t _{4 when the} predetermined time has elapsed
At, the rotation of the main motor is also stopped and the loading operation ends.

After completion of this loading operation, when video data is sent from an external device such as a host computer in the online mode, the control unit 37 opens the shutter 16,
The main motor 36 is driven to scan the photosensitive member 41 with the scanning light beam.
Record to.

FIG. 5 is a timing chart for explaining the operation during non-printing, and FIG. 6 is a timing chart for explaining the operation during printing. In these figures, (a) shows the output of the light receiving element 44. , (B) show the output of the AOM 27. Here, the shutter 40 is disposed on the front surface of the photoconductor 41, and is closed so that the photoconductor 41 is not exposed to light during non-printing and is opened during printing. On the other hand, since the light receiving element 44 for outputting the horizontal synchronizing signal is arranged on the front surface of the shutter 40, the rotary polygon mirror 37 is irrespective of the opening / closing operation of the shutter 40, that is, the printing operation or the non-printing operation. A horizontal synchronizing signal can be output as long as the scanning light beam is reflected from the.

As a result, the rotational operation of the rotary polygon mirror 37 can be monitored by measuring the cycle of the horizontal synchronizing signal output from the light receiving element 44 even when the shutter 40 is closed and non-printing is being performed. With such a configuration, the conventional surface detection sensor 24 need not be provided, the number of parts can be reduced, and the structure around the rotary polygon mirror 37 can be simplified.

Further, as described above, since the shutter 40 also functions as a part of the transport guide at the time of loading, a jam does not occur at the time of loading.

The present invention is not limited to the above embodiment. For example, the optical system for making the output beam of the light source 25 incident on the rotary polygon mirror 37 may be the one shown in FIG. 7 with the shutter 2 removed.

Further, the light source may be a laser light source other than the He-Ne laser light source as long as it can obtain sufficient energy for exposing the photosensitive member.

(Effects of the Invention) As described above, according to the present invention, the rotating operation of the rotary polygon mirror can be monitored even during non-printing without increasing the number of parts with a simple configuration, and the occurrence of a jam at the time of loading. A light beam scanning device using a rotating polygon mirror that can be prevented can be realized.

[Brief description of drawings]

1 and 2 are configuration diagrams showing a mechanical configuration of an embodiment of the present invention, and FIG. 3 is a configuration diagram showing a main portion of an electrical configuration of the embodiment of FIGS. 1 and 2. 4 to 6 are timing charts for explaining the operation of the embodiment of FIGS. 1 to 3, FIG. 7 is a block diagram showing an example of a conventional device, and FIG. 8 is the device of FIG. 3 is a timing chart for explaining the operation of FIG. 25 ... Laser light source, 26 ... ND filter 27 ... AOM lens, 28 ... AOM 29, 34, 36, 42, 43 ... Mirror 30, 35 ... BE (beam expander) 31 ... Pinhole 32 , 39 ... CL (Cylindrical lens) 37 ... Rotating polygonal mirror, 40 ... Shutter 41 ... Photoconductor, 44 ... Photodetector 51 ... Supply magazine 53, 54 ... Loading roller 55 ... Loading motor 59 ... ... Media path sensor 60 ... Main roller, 61 ... Take-up magazine 62 ... Loading sensor 66 ... Main motor, 67 ... Control section 68 ... Transport guide

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G03G 15/04 116 9122-2H (56) References JP-A-62-81651 (JP, A) Special features Kai 59-80057 (JP, A) JP 56-140319 (JP, A) JP 60-7416 (JP, A) JP 45-31609 (JP, B1)

Claims (1)

[Claims] 1. In a light beam scanning device which reflects a light beam from a light source by a rotating polygon mirror and gives it to a photoconductor through a condenser lens, a shutter for opening and closing a scanning light beam is provided on the front face of the photoconductor. At the same time, the light beam scanning device is characterized in that the shutter is used as a part of a conveyance guide of the photoconductor at the time of loading.