JPH02103012A - recording device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention relates to a recording device that records image information on a recording medium by scanning a light beam, and particularly relates to a recording device that records image information on a recording medium by scanning a light beam. The present invention relates to a recording device equipped with a recording device.

[Prior Art] Conventionally, in an image scanning recording device such as a laser beam printer that records image information by scanning a light beam modulated by an image signal on a recording medium in the main scanning and sub-scanning directions, it is difficult to determine the position of the light beam. Each time the reference value changes in the main scanning direction, image information is recorded with the modulated light beam.

Conventionally, basic clock signals for reading image information from memory etc. when recording such image signals,
The clock signal that detects the light beam at any point on the main scan and detects synchronization abnormalities in the horizontal synchronization signal (BD signal) generated in synchronization with this detector is generated using a crystal resonator.
It was obtained by oscillating it using a TL IC, a CMO5 gate circuit, or the like.

[Problems to be Solved by the Invention] However, since the basic clock signal has conventionally been generated using a crystal resonator, there have been the following drawbacks.

(1) Since a crystal oscillator is used, only a basic clock signal with a fixed period can be generated, and if the frequency is to be changed, the crystal oscillator must be physically changed.

(2) The frequency cannot be changed in the short term in response to problems such as motor rotation failure.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a recording device that enables flexible clock generation.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a recording device that scans and records a light beam on a recording medium, and a motor for driving a rotating polygon mirror that scans the light beam. a rotation detection means for detecting the rotation state of the motor; a control means for controlling the number of pulses generated in one rotation of the polygon mirror of the rotation detection pulse signal detected by the detection means to be the same as the number of surfaces of the polygon mirror; The device is equipped with a clock generating means for generating a clock signal proportional to the signal.

[Function] According to the present invention, an arbitrary number of pulse signals for detecting the rotation of a polygon motor that drives a rotating polygon mirror that scans a light beam is selected without using a crystal oscillator, and, for example, phase synchronization is performed. Loop (PIIASE LOCKEDLOOP:
By providing a configuration that generates a basic clock signal using a circuit (hereinafter abbreviated as PLL), it is possible to change the frequency of the generated basic clock signal by simply changing some control constants of the PLL circuit, etc. . moreover,
Since the rotation detection pulse signal is used as the reference human power signal,
It becomes possible to generate a basic clock signal that follows rotational fluctuations of the polygon motor.

【Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a diagram showing the configuration of the light beam scanning system. As shown in this figure, a semiconductor laser 305 is driven by a laser control circuit 305 to emit a light beam. The light beam is scanned onto a photosensitive drum 302 by a rotating polygon mirror 202 rotating at a constant speed, and is transferred onto a transfer material (such as paper) 301 using a conventional electrophotographic process and output.

In addition, a synchronization signal in the main scanning direction (BD scratch signal) is detected by a photodetector 304 provided at an arbitrary point on the main scanning axis of the light beam, is waveform-shaped by a waveform shaping circuit 307, and is combined with the BD signal 102. Become.

The rotating polygon mirror 202 rotates at a constant speed with the configuration shown in FIG. The rotating polygon mirror 202 is a polygon motor 20
A disk 205 with several slits is fixed to the polygon collector 203, and an encoder or the like is configured to detect the slits in the photointerrupter 204 by rotation of a motor.
Pulse signal (FG) for detecting motor rotation speed
207 is output.

The FG signal 207 is waveform-shaped by the waveform shaping circuit 206 and output. The output TACH signal 101 is
It is fed back to the motor control circuit 208. The Chi-Yu control circuit 208 is composed of a motor control IC such as TC9142 manufactured by Toshiba, and the polygon motor 203 is controlled to rotate at a constant speed.

TACH signal 101 is also supplied to the clock signal generation circuit shown in FIG.

FIG. 1 is a diagram showing a clock signal generation circuit according to an embodiment of the present invention.

TACH signal 101 is input to TACH signal shaping circuit 107. The clock signal fTA113 shaped by the TACH signal shaping circuit 107 is a commercially available Motorola M
A phase-locked loop (PI (ASELO) such as C4044
OKED LOOP: PLL ) circuit 104 compares the phase with the frequency-divided output fo/n 114 of VCO (voltage controlled oscillator) 105 and controls the input terminal of VCO (voltage controlled oscillator) 105 .

VCO105 has an output frequency f according to the input terminal.

112, and the output frequency fo 112 is the frequency divider 10
The output frequency fo 1 is divided into l/mouth by 8, is fed back to the PLL 104, and is proportional to the reference signal 113.
12 can be obtained.

The output clock signal fo 112 of the V OC 105 is input to the frequency divider 106 and divided by 17m (m is an integer of 1 or more). A synchronization signal (clock signal F103 synchronized with the BD double signal 102) can be obtained.

In an image scanning recording apparatus such as the one shown in this embodiment, mainly a laser beam printer, a basic clock signal F103 and a horizontal synchronization signal 102 are transmitted from the printer to an external control device 11.
Send to 0. Then, as shown in FIG.
During this time, image data (Video) 111 is sent to the printer in synchronization with the basic clock signal F103. Human-generated image data (Video) (in response to i ill)
C. A laser control circuit 306 drives the semiconductor laser 305 to record image information on the photosensitive drum-F.

As shown in FIG. 4, the TACH number shaping circuit 107 selects the T A CH (z number 101 ) and creates the same number of fTA numbers 113 as the BD number 102 .

Further, the clock signal fo 112 generated by the VCO 115 and the PLL 104 is output from the VCO 105 at the input timing of the human input signal LrA 113 of the PLL 104.
output clock signal fo 112 or output clock (g
Due to the phase synchronization of the - signal F103, there is a fluctuation period Tf 501 of the output frequency, as shown in FIG.

As shown in FIG. 6, the image recording device receives a horizontal synchronizing signal (
From the BD double signal, the video signal is output in synchronization with the basic clock signal F for 16 hours after the TA time.

Therefore, when the image data (Video) signal is input manually, if the fluctuation period Tf of the basic clock signal F occurs due to phase synchronization, the printed image will fluctuate.

Therefore, in the TACH number shaping circuit 107, using a counter and a gate circuit, synchronization is performed so that the fluctuation time Tf does not overlap between the video signal human power signal human power periods, and furthermore, the number of pulses of fTA113 generated in one rotation is It has the function of dividing the frequency to match the number of surfaces of the rotating polygon mirror. Therefore, the number of pulses of the TACH signal generated by one rotation of the polygon motor needs to be twice as many as the number of pulses of the rotating polygon mirror (k is a constant of 1 or more).

In such a configuration, if a rotational fluctuation of the polygon motor 203 occurs, the period of the TACH signal 101 will fluctuate. However, since the clock signal fo 112 is generated using the TACH number 101 as the basic signal,
The clock signal fo follows the periodic fluctuation of the TACH signal.
112 also changes.

Therefore, the basic clock signal F103, which is a timing signal for outputting image data, also fluctuates, and image information scanned onto the photosensitive drum, such as vertical lines, becomes a straight line, and abnormal images such as distortion and image protrusion do not occur.

In addition, the frequency division ratio of the frequency divider 108 is determined by the central processing unit jZ (CP
The frequency of the basic clock signal FI03 can be changed by changing it using the internal control circuit 109 such as IJ). That is, by changing the image data readout timing of the external control device, the image density in the main scanning direction can be changed.

Furthermore, by changing the frequency of the basic clock signal F103 from the external control device 110 through the internal control circuit 109, the image density in the main scanning direction can be controlled by the external control device 110.
It can be changed by following instructions from 10 onwards.

As another embodiment of the present invention, as a method of generating the pulse signal fTA113 input to the PLL circuit 104,
As mentioned above, using the TACH signal shaping circuit 107,
It is synchronized with the signal 102, and furthermore, the output frequency fluctuation period Tf is the video signal human power time T. A method other than generating the reference signal fA as before is conceivable.

As shown in FIG. 7, the disk 205 fixed to the rotating polygon mirror 202 is aligned with the surface of the rotating polygon mirror, and the output clock fluctuation time Tf6) of the clock generation circuit is
Slip in advance so that the eo signal comes outside of the human power time TB.
-701 and the rotating polygon mirror 202, the output pulse signal TACH signal is directly outputted as shown in FIG.
By manually inputting the LL circuit 104, the TACH shaping circuit becomes unnecessary and the same function can be realized.

Furthermore, as another embodiment of the present invention, as shown in FIG. The human input signal is fTA113.

That is, during one rotation time Ts of the rotating polygon mirror 202,
Pulse signals having exactly the same phase are selected and used as TTA.

PLL circuit 1 using two or more TACH signals per revolution
When operating 04, the slit 701 as shown in FIG.
make. At this time, the slits must be divided with high precision. This is because, if the division accuracy is low, the period of the pulse signal of the TACH signal 101 will be irregular, and only the output reference clock signal F with low accuracy can be obtained. Therefore, a disk with highly precise slits is required.

According to the tree layer side, only one slit is used for one rotation, and the slit division error that was the problem just now is not a problem at all, and a highly accurate output reference clock signal F can be obtained.

In addition, as shown in FIG.
02 By matching the phases, the polygon mirror 20
By setting one pulse to be generated at every 21 rotations, fixing the output clock fluctuation time Tf of the clock generation circuit to be in the non-image area, and directly inputting it manually to the PLL circuit +04 as shown in Fig. 8. , similar functionality can be achieved.

[Effects of the Invention] As explained above, according to the present invention, the number of pulses of the pulse signal (TACH signal) for detecting the rotation of the polygon motor is set to be the same as the number of surfaces of the polygon mirror or one pulse per rotation of the motor. The pulse signal is used as a reference signal, and the PL
By generating an image clock using an L circuit or the like, a highly accurate oscillation circuit can be realized without using a crystal resonator.

Furthermore, by selecting the phase of pulse No. 18 that is synchronized with the BD signal, the vCO output control timing can be brought to the non-image area, and an image without fluctuation can be formed.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a recording apparatus 1t embodying the present invention, FIG. 2 is a diagram depicting a scanner motor drive circuit embodying the present invention, and FIG. 3 is a diagram depicting a scanning system embodying the present invention. 4 to 6 are timing diagrams in which the present invention is implemented, FIG. 7 is a diagram showing another embodiment, FIG. 8 is a diagram showing another embodiment, and FIG. 9 is a diagram showing still another embodiment. FIG. 10 is a diagram showing still another embodiment. 101... TACH word, 102... BD signal, 103... Output reference clock signal F, lQ4...P
LL circuit, 105...VCO circuit, 106.108...Frequency divider, 107...TACH signal shaping circuit, 109...CPU. 110...External control circuit, 111-Video signal, 112...VCO output clock fo, 113...P
LL human power pulse signal fTA+114 ...Feedback No. 43 fo/n, ...polygon mirror, ...polygon motor, ...sensor, ...disc, ...waveform shaping circuit, ...FG signal , ...Motor control circuit, ...Paper, ...Photosensitive drum, ...Scanning beam, ...Optical receiver, ...Semiconductor laser, ...Laser control circuit, ...BD waveform Shaping circuit, ...slit. BD TaCl3 1'T, 4 rA Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 1O

Claims (1)

[Claims] 1) A recording device that scans and records a light beam on a recording medium, including a motor for driving a rotating polygon mirror that scans the light beam, and a rotation that detects the rotational state of the motor. a detection means; a control means for controlling the number of pulses generated in one rotation of the polygon mirror of the rotation detection pulse signal detected by the detection means to be the same as the number of surfaces of the polygon mirror; and a control means for generating a clock signal proportional to the pulse signal. What is claimed is: 1. A recording device comprising clock generation means for generating a clock. 2) The recording apparatus according to claim 1, wherein the clock signal is frequency-divided and a basic clock signal synchronized with a horizontal synchronization signal is generated.