JPH0736600B2 - Exposure device for laser recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser recording device such as a laser printer or a laser plotter used as an output device of an information processing system, and particularly to a speed of a scanning unit for scanning a laser beam on a recording medium. The present invention relates to an adjustable exposure device for a laser recording device.

2. Description of the Related Art In a conventional laser printer, a polygon motor that drives a polygon mirror (rotating polygon mirror) that scans a laser beam does not perform printing waiting for data from the host when the main power of the printer is turned on. Even at times, it always rotates at the specified rotation speed. Therefore, in a restricted printer, the polygon motor is constantly rotating at a high speed, and the rotation speed of the polygon mirror is 10,000 rpm or more. Therefore, the wind noise of the polygon mirror and the noise of the polygon motor are large, and the polygon motor There was a drawback that the life was shortened.

In order to eliminate such a defect, there is a method in which the rotation of the polygon motor is stopped and the polygon motor is rotated in response to a print request signal when the printing waiting for data from the host is not performed. In such an apparatus, there is no problem when the print speed is low (for example, about 8 sheets per minute), but when the print speed is high (10 or more sheets per minute), the polygon motor reaches the specified rotation speed and stabilizes. Since it takes a long time to print, the first printing after waiting for data from the host is delayed, and there is a drawback that the printing efficiency is reduced. Furthermore, in the first print when the main power is turned on, it takes a longer time for the polygon motor to stably rotate at the specified rotation speed than in the first print after waiting for the data from the normal host. There is a drawback.

Aim The present invention solves the drawbacks of the prior art as described above, eliminates noise of the scanning means when waiting for data, extends the life of the scanning means, and allows laser recording capable of immediately performing the first print after waiting for data. An object is to provide an exposure apparatus for an apparatus.

In order to achieve the above-mentioned object, the present invention comprises a laser generating means for generating a laser beam modulated according to recording data,
In an exposure apparatus of a laser recording apparatus, which has a scanning unit that scans and exposes a recording medium that is conveyed with a laser beam generated from a laser generating unit, and a control unit that controls the scanning unit, transfer of recording data is performed. When started, the scanning means is driven at a speed lower than that at the time of recording, after the transfer of the recording data, the scanning means is driven at a specified speed at the time of recording when a recording request signal is generated, and after the recording is completed, the scanning means is driven. The control means controls the drive to be stopped, and the control means controls the scanning means to be driven at a speed lower than that at the time of printing for a certain time when the main power source of the printing apparatus is turned on. It is a thing. Hereinafter, a specific description will be given based on an embodiment of the present invention.

FIG. 4 shows the configuration of the optical system of the laser printer.

A polygon mirror 4 is arranged in the housing 2, and the polygon mirror 4 is rotated by a polygon motor 5 to scan a laser beam. An LD unit 6 is arranged outside the housing 2. The LD unit 6 generates laser light modulated according to image information. A window 8 is provided in the housing 2 to allow the laser light generated from the LD unit 6 to pass through. A lens pointing frame 10 and a cylindrical lens 14 are arranged between the window 8 in the housing 2 and the polygon mirror 4, and a beam compressor lens 12 is fitted in the lens pointing frame 10.

Further, fθ lenses 16 and 18 and a mirror 20 are arranged in the housing 2. The fθ lenses 16 and 18 are mirrors for the laser light reflected and scanned by the polygon mirror 4.
When entering the mirror 20, the mirror 20 is adjusted so that it does not enter at an angle even at the end of the mirror 20 and enters at a right angle. A slit 22 is provided on the bottom surface of the housing 2 to allow the laser light reflected by the mirror 20 to pass through. A cylindrical lens and a photoconductor (not shown) are arranged below the housing 2.

A synchronous mirror 24 is arranged near one end of the mirror 20, and the laser beam scanned by the polygon mirror 4 is reflected. A window 26 for passing the laser light reflected by the synchronous mirror 24 is provided in the housing 2, and a synchronous sensor 28 for detecting the laser light having passed through the window 26 is provided outside the window 26.
Are arranged.

The laser light generated by the LD unit 6 and modulated by the image information passes through the window 8 of the housing 2, is condensed by the beam compressor lens 12, and is a cylindrical lens.
After passing through 14, it is reflected by the rotating polygon mirror 4 and scanned. The laser light reflected by the polygon mirror 4 passes through fθ lenses 16 and 18,
After being scanned on the mirror 20 and reflected by the mirror 20, after passing through a slit 22 and a cylindrical lens (not shown) arranged at the bottom of the housing 2,
Main scanning is performed on a photoconductor (not shown) to expose the photoconductor to form an electrostatic latent image.

The photoconductor is conveyed (sub-scanning) by the drive motor and is uniformly charged in advance by corona discharge or the like. After being exposed by the laser beam as described above, it is developed with toner, and the developed toner image is printed on paper or the like. Is transcribed to. Also,
The laser light reflected and scanned by the polygon mirror 4 passes through the fθ lenses 16 and 18, is scanned on the mirror 20, and is incident on the synchronous mirror 24. Sync mirror 24
The laser light incident on is reflected by the synchronous mirror 24,
After passing through the window 26, it is incident on the synchronization sensor 28. The synchronization sensor 28 detects the incident laser light and determines whether or not it coincides with the synchronization signal.

The present invention is, for example, an apparatus that controls the rotation of a polygon motor 5 that drives the polygon mirror 4 of such a laser recording apparatus.

FIG. 1 shows an overall schematic view of an embodiment of the exposure apparatus of the present invention.

Laser printer 30 is connected to host 32 and controller
34 and a plotter control circuit 36. Host 32
Is connected to the controller 34 of the laser printer 30 and generates data according to image information, a print request signal, etc.
Send to controller 34. The controller 34 is connected to the plotter control circuit 36, and sends various control signals to the plotter control circuit 36 according to signals sent from the host 32. The plotter control circuit 36 controls the rotation of the polygon motor, the modulation of the laser light, and other control of the exposure device according to the signal sent from the controller 34.

FIG. 2 shows an internal block diagram of the plotter control circuit 36 shown in FIG.

I / O 42, CPU 44, video signal control circuit on system bus 40
46, RAM4, ROM50 are connected respectively.

The I / O 42 is connected to the controller 34 by a data line 52, a print request line 54, and a control line 56, and receives data according to image information sent from the host 32 through the controller 34, a print request signal, a control signal, and the like. Send to system bus 40. Further, the I / O 42 is connected to the polygon motor control circuit 62 by control lines 58 and 60, and sends a signal sent from the system bus 40 to the polygon motor control circuit 62. The polygon motor control circuit 62 is connected to the polygon motor 5 and controls the polygon motor 5 by a signal sent from the I / O 42.

The video signal control circuit 46 is connected to the LD unit 6 by a signal line 66, and sends a signal for modulating the laser light to the LD unit 6 according to the image signal sent from the system bus 40. RAM4
Reference numeral 8 denotes a video signal control circuit via the system bus 40 when data such as characters is stored, for example, when one page is stored.
Sent to 46. The ROM 50 stores the program executed by the CPU 44. The CPU 44 executes a program stored in the ROM 50 to control each unit.

A block diagram of one embodiment of the polygon motor control circuit 62 of FIG. 2 is shown in FIG.

The select circuit 70 uses the signal line 72 to oscillate the low rotation oscillation circuit 76,
A low-frequency pulse signal for low-speed rotation of the polygon motor 5 from the low-speed oscillation circuit 76 and a high-speed oscillation circuit 78 are connected to the high-speed oscillation circuit 78 by signal lines 74, respectively.
The high-frequency pulse signals for high-speed rotation of the polygon motor 5 are received from the signal lines 72 and 74, respectively, and
It is connected to a polygon motor driver 82 by a control line 80. The select circuit 70 is connected to the I / O 42 by the control lines 58 and 60, and receives the low-speed rotation instruction signal and the high-speed rotation instruction signal of the polygon motor from the I / O 42 from the control lines 58 and 60, respectively, to reduce the rotation speed. The pulse signal for low speed rotation of the polygon motor 5 from the oscillation circuit 76 for oscillation and the pulse signal for high speed rotation of the polygon motor 5 from the oscillation circuit for high rotation 78 are selected and sent to the polygon motor driver 82. The polygon motor driver 82 drives the polygon motor 5 by the signal from the select circuit 70.

The operation will be described with reference to the time charts of FIGS.

Figure 5 shows the host 32 at a certain time after the main power is turned on.
The control of the rotation of the polygon motor 5 when the data is not transferred from FIG.

When the main power supply of the laser printer is turned on (time t1), the polygon motor 5 is rotated at a low speed during the warm-up period (T1) and for a certain period after the warm-up is completed. That is, when the main power is turned on, the controller 34
A high level signal is sent from the control line 56 to the I / O 42. This signal is sent to the CPU 44 via the system bus 40. This causes the CPU 44 to generate a low-speed rotation instruction signal that causes the polygon motor to rotate at a lower speed than during recording, and a high-level signal is output from the I / O 42 to the control line 58 via the system bus 40 and sent to the select circuit 70. To be

The select circuit 70 selects a pulse signal for low-speed rotation of the polygon motor 5 from the low-speed oscillation circuit 76 by a low-speed rotation instruction signal from the control line 58 to select the polygon motor driver.
Send to 82. The polygon motor driver 82 rotates the polygon motor 5 at a low speed by this signal.

The rotation speed of the low-speed rotation is a rotation speed at which the wind noise of the polygon mirror 4 and the sound of the polygon motor do not generate noise, and the time required to reach the specified rotation speed during printing from this rotation speed is about 2 to 3 A rotation speed of seconds is desirable.

After the warm-up time (T1) has passed, the printer is ready (time t2) and a similar signal continues for a certain time T2, and the polygon motor 5 continues to rotate at a low speed. After a certain time T2, the controller
The signal sent from 34 to the control line 56 becomes low level, which causes the CPU 44 to generate a signal to stop the rotation of the motor, the I / O 42 to generate a low level signal to the control lines 58 and 60, and the select circuit 70 Sent to. The select circuit 70 stops sending signals from the low rotation oscillation circuit 76 and the high rotation oscillation circuit 78 to the polygon motor driver 82 in response to the low level signal. As a result, the polygon motor driver 82 stops driving the polygon motor 5, and the polygon motor 5 stops (time t3).

After that, when data is not transferred from the host 32 to the controller 34, the controller 34 passes through the control line 56.
Since a low level signal is sent to the I / O 42, the polygon motor 5 remains stopped as described above.

When the data is transferred from the host 32 to the controller 34 (time t4), the data is stored in the controller 34 and a high level signal is sent from the controller 34 to the I / O 42 through the control line 56. A high level signal from the control line 56 is sent to the CPU 44 via the system bus 40. CPU44
This generates a low speed rotation instruction signal for rotating the polygon motor 5 at a low speed, and the I / O 42 is transmitted via the system bus 40.
Outputs a high level signal from the control line 58 to the select circuit 70.

The select circuit 70 selects a signal for low speed rotation of the polygon motor 5 from the low rotation oscillation circuit 76 according to a high level signal from the control line 58 and sends it to the polygon motor driver 82. The polygon motor driver 82 rotates the polygon motor 5 at a low speed by this signal.

When a form feed signal for instructing printing is sent from the host 32 to the controller 34 (time t5), a high level signal is sent from the controller 34 to the I / O 42 through the print request line 54. Based on this signal from the I / O 42, the CPU 44 generates a signal that makes the rotation speed of the polygon motor 5 a high-speed specified rotation speed, and a high level signal is output from the I / O 42 to the control line 60 via the system bus 40. , To the select circuit 70.

The select circuit 70 selects a signal for high speed rotation of the polygon motor 5 from the high rotation oscillation circuit 78 according to a high level signal from the control line 60 and sends it to the polygon motor driver 82. Based on this signal, the polygon motor driver 82 rotates the polygon motor 5 at a high speed specified rotation speed.

At this time, a signal of image information such as characters is sent from the video signal control circuit 46 to the LD unit 6, and the LD unit 6 modulates the laser light by this signal. The laser light modulated according to the image information is scanned by the polygon mirror 4 rotated by the polygon motor 5, and printing is performed.

When printing is completed, the signal output from the controller 34 to the control line 56 becomes low level. The CPU 44 generates a signal for stopping the rotation of the polygon motor 5 by this signal from the I / O 42, and the control line 5 from the I / O 42 via the system bus 40.
A low level signal is output to 8 and 60. The select circuit 70 stops sending signals from the low rotation oscillation rotation 76 and the high rotation oscillation circuit 78 to the polygon motor driver 82 in response to the low level signal (motor off signal), and the polygon motor driver 82 causes the polygon motor driver 82 to move. The drive of 5 is stopped.

Although not shown, when data is transferred from the host 32 to the controller 34 again, the polygon motor 5 is similarly rotated at a low speed, and when a form feed signal for instructing printing is sent from the host 32 (print The request line 54 is rotated to a high level at a specified high speed, and the rotation is stopped at the end of printing.

FIG. 6 shows a case where data is transferred from the host 32 to the controller 34 immediately after the main power is turned on. In this case, when the main power is turned on (time t11), the fifth
As in the case shown in the figure, the polygon motor 5 is rotated at a low speed. When data is transferred from the host 32 to the controller 34 within a relatively short time after the printer is ready (time t12) (time t13), the data is transferred from the controller 34 to a high level to the I / O 42 through the control line 56. Signal continues to be sent from the controller 34 to the print request line 54, and the polygon motor continues to operate as shown in FIG. 5 when a certain time (T2) has elapsed after print ready. Continues to rotate at low speed without stopping.

When a form feed signal for instructing printing is sent from the host 32 to the controller 34 and a high level signal is sent to the print request line 54 (time t14), the controller 3
A high level signal is sent to the I / O 42 from the print request line 54 from the 4 and the select circuit 70 is sent from the control line 60 as described above.
A high level signal is sent to the polygon motor 5, and the polygon motor 5 rotates at a high speed specified rotation speed.

When printing is completed, polygon motor 5 stops (time
t15), when data is sent from the host 32 to the controller 34 again (time t16), the polygon motor 5 rotates at a low speed and a form feed signal is sent (time t1).
7), rotates at a high speed specified speed.

The polygon motor control circuit 62 uses other means instead of selecting the pulse signals from the low rotation oscillation circuit 76 and the high rotation oscillation circuit 78 by the selection circuit 70 as described above. It is also possible to generate a signal for high speed or a signal for high rotation.

According to the present embodiment, when the data is transferred from the host 32 to the controller 34, the polygon motor 5 is rotated at a low speed, and when the printing is started by the form feed signal, the speed is increased to a high speed specified rotation speed. Therefore, as compared with the conventional example (f) shown in FIG. 5, when the polygon motor is stopped and the printing is started by the form feed signal, the rotation is started at a high speed. Since the high-speed specified rotation speed is reached in time, the first printing after waiting for data from the host 32 is delayed and the printing efficiency is not lowered unlike the conventional example (f).

Further, compared to the case where the polygon motor is always rotated at a high speed as in the conventional example (g), the wind noise of the polygon mirror 4 and the noise of the polygon motor are less, and the life of the polygon motor is extended.

Further, since the polygon motor 5 is rotated at a low speed when the main power is turned on, even if data is transferred immediately after the main power is turned on, the rotation is started at a low speed after the data transfer. As compared with the case, the rotation continues at a low speed for a long time before the printing starts. In the first print when the main power is turned on, it takes a longer time until the polygon motor 5 stably rotates at the specified rotation speed, as compared with the first print after waiting for the data from the normal host 32. In short, this low-speed rotation for a long time allows the rotation speed to reach the specified rotation speed promptly during printing. Therefore, the first print when the power is turned on can be efficiently performed in a short time.

Effect According to the present invention, since the scanning means is driven at a low speed during data transfer, the high speed specified rotation speed is reached in a short time during printing, so that the first printing after waiting for data from the host is performed quickly. be able to.

Further, since the scanning means is rotated at a low speed only during data transfer, noise of the scanning means is reduced and the life of the scanning means is extended.

Further, since the scanning means is rotated at a low speed when the main power source is turned on, the first print when the main power source is turned on can be efficiently performed in a short time.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an entire embodiment of an exposure apparatus of the present invention, FIG. 2 is a block diagram of the plotter control circuit of FIG. 1, and FIG. 3 is a polygon motor control circuit of FIG. FIG. 6 is a block diagram, FIG. 4 is a configuration diagram of an optical system of a laser printer, and FIG. 5 is a time chart showing control of rotation of a polygon motor when data is not transferred within a fixed time after power-on, FIG. FIG. 4 is a time chart showing control of rotation of the polygon motor when data is transferred immediately after power-on. Description of main part symbols 4 …… Polygon mirror 5 …… Polygon motor 6 …… LD unit 30 …… Laser printer 32 …… Host 34 …… Controller 36 …… Plotter control circuit 54 …… Print request line 56 …… Control Lines 58, 60 …… Control line 62 …… Polygon motor control circuit 70 …… Select circuit 76 …… Low rotation oscillation circuit 78 …… High rotation oscillation circuit 82 …… Polygon motor driver

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Nishitoku 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) Reference JP-A-56-22415 (JP, A)

Claims (1)

[Claims] 1. A laser generating means for generating a laser beam modulated according to recording data, and a scanning means for scanning a laser beam generated by the laser generating means on a conveyed recording medium for exposure. In the exposure apparatus of the laser recording apparatus having a control unit for controlling the scanning unit, the control unit is configured to, when transfer of recording data is started,
The scanning means is driven at a speed lower than that at the time of recording, and when the recording request signal is generated after the transfer of the recording data, the scanning means is driven at a specified speed at the time of recording, and after the recording is completed, the scanning means is driven. When the main power supply of the printing apparatus is turned on, the scanning means is driven at a speed lower than that at the time of printing, and when the printing data transfer is not started even after the elapse of a certain time, the scanning is performed. An exposure apparatus of a laser recording apparatus, characterized in that the driving of the means is controlled so as to be stopped.