JPH06206343A - Multi-beam recorder - Google Patents

Abstract

PURPOSE:To ensure detection of a beam position, reduce an effect of a shape of a beam and enhance the accuracy and reliability. CONSTITUTION:A multi-beam recorder is provided with a recording light source having n (n>=2) light emitting parts independently moldulated in synchronism with a moldulating clock by an image information signal to emit (n) beams from the light emitting parts of the recording light source. The beams are condensed on (n) minute light spots. An image is recorded by exposure-scanning a recording medium by the light spot. One or more light-receiving parts 31 each receiving at least two out of the (n) beams are disposed within an exposure scanning range of the light spot. A first means 34 is provided for detecting (n) beams in order on a timing signal by the output signal of the light-receiving parts 31 and successively extinguishing the beams for a predetermined time. A period of the timing signal is determined to be 1/K (K>=1) of the period of the moldulating clock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-beam recording apparatus for simultaneously recording a plurality of lines using a recording light source having a plurality of light emitting portions which can be independently modulated.

[0002]

2. Description of the Related Art Image recording devices such as laser printers, which combine electrophotographic technology and laser scanning technology, can use plain paper and can obtain high-quality images at high speed. It has been widely used in copiers.

FIG. 3 shows an example of a laser optical system used in a laser printer. A light source 11 made of a semiconductor laser is modulated by an image signal in a drive circuit, and a laser beam from this semiconductor laser 11 is deflected by a rotary polygon mirror 13 via a lens 12. The laser beam from the rotary polygon mirror 13 is imaged as a minute light spot on the drum-shaped photoconductor 15 by the imaging lens 14 including an fθ lens. This light spot scans and exposes the photoconductor 15 by the rotation of the rotary polygon mirror 13 and the drive mechanism of the photoconductor 15 to form an electrostatic latent image of the image. In this case, the photoconductor 15 is uniformly charged by the charger and then an electrostatic latent image is formed by the above exposure. Further, the synchronous detection light receiving element 16 detects the laser beam from the imaging lens 14 outside the image area on the scanning line on the scanning start side. The output signal of the light-receiving element 16 for synchronization detection is binarized at a threshold level to become a beam position detection signal, and the beam position detection signal controls the image writing start position in the main scanning direction.

In a laser printer having such a laser scanning optical system, 10 A4 size images are produced in 1 minute.
In order to realize a laser scanning optical system that outputs 0 sheets, the speed of the photosensitive member is about 500 mm / sec, and the rotational speed r (rpm) of the rotary polygon mirror is given by the following expression (1). r (rpm) = V ₀ × DPI × 60 / (25.4 × N) (1) where V ₀ is the speed (mm / sec) of the photoconductor, and DPI can be recorded per inch. Number of dots, generally 300-4
00, N is the number of reflecting surfaces of the rotating polygon mirror, and is generally 6 to 10. V ₀ = 500, DPI = 300, N =
Substituting 8 into the equation (1), r becomes 44291 (rpm).

At such a high rotational speed, the rotary polygon mirror cannot use the conventional ball bearing as a bearing for supporting the rotary shaft, and requires special bearings such as a fluid bearing and a magnetic bearing, resulting in an increase in cost. Further, the modulation frequency of the semiconductor laser, which is the light source, becomes high, and it becomes necessary to speed up the data transfer from the laser control circuit and the host machine to the laser side, which complicates the circuit and increases the cost.

Further, in the laser printer, there is a multi-beam recording system in which a plurality of laser beams from a plurality of light sources are deflected and scanned by one rotating polygon mirror to record a plurality of lines at the same time in order to increase the speed. . In this multi-beam recording method, if the number of laser beams from the light source is M, the rotation number of the rotary polygon mirror and the modulation frequency of the laser are 1 / M, and high-speed recording is possible.

FIG. 4 shows an example of a laser scanning optical system using as a light source a plurality of semiconductor lasers used in the multi-beam recording method. A plurality of laser beams diverged and emitted from the light sources 17 ₁ and 17 ₂ each including a laser diode having a plurality of independent light emitting points are made into parallel light beams by the collimator lens 18, and the rotary polygon mirror 20 is made by the cylinder lens 19. Is narrowed down in the sub-scanning direction in the vicinity of the reflection surface of the. The plurality of laser beams from the cylinder lens 19 are commonly deflected by the rotary polygon mirror 24, and the recording medium 2 formed of a photoconductor is formed by the imaging lens 21 formed of an fθ lens.
The electrostatic latent image is formed on the recording medium 26 as a minute laser beam on the recording medium 2 and each laser beam is focused so as to have a pitch corresponding to the recording density. Here, the light sources 17 ₁ and 17 ₂ are modulated by the image signal in the drive circuit,
A laser beam having an intensity corresponding to the image signal is output. The recording medium 22 is driven by a motor to rotate in the sub-scanning direction, is uniformly charged by a charger, and then a plurality of laser beams form electrostatic latent images for a plurality of lines in one main scanning.

The image forming lens 21 is an anamorphic lens having different focal lengths in the main scanning direction (direction in which the laser beam is scanned by the rotary polygon mirror 20) and the sub scanning direction.
In the sub-scanning direction, the reflecting surface of the rotary polygon mirror 20 and the recording medium 26
Are designed to have a geometrically conjugate relationship.
This is to configure a correction optical system for reducing the variation in pitch between scanning lines due to an angular error (reflection surface tilt) with respect to the rotation axis of each reflection surface of the rotary polygon mirror 20. The cylinder lens 19 has a function of setting the laser beam diameter on the recording medium 22 in the sub-scanning direction to an appropriate size. Further, the light receiving element for synchronization detection detects the laser beam from the imaging lens 21 within the scanning area and outside the image scanning recording area. The output signal of the synchronization detecting light receiving element is binarized at the threshold level, and the binarized signal is separated for each laser beam to obtain a beam position detection signal. The image writing start position in the main scanning direction of the laser beam is controlled.

In the multi-beam recording method, when a plurality of lines of data are simultaneously recorded in one main scan by using a plurality of laser beams, a straight line connecting the centers of the light emitting points of the plurality of laser beams is mainly used. If the scanning direction (direction in which the laser beam is scanned) is made orthogonal to each other, the scanning timing of the laser beam at each light emitting point becomes the same, so that the phase synchronization may be performed by one light emitting point. Alternatively, if the pitches of adjacent laser beams are known, the beam position detection signal for one laser beam and the modulation clock of each laser beam (hereinafter the modulation clock is referred to as a pixel clock) may be synchronized.

In the multi-beam recording method, when a semiconductor laser array having a plurality of light emitting points in one chip is used as a recording light source, a pitch (interval) in the sub-scanning direction (direction in which a recording medium is sent) Depends on the pitch of the light emitting points of the semiconductor laser array. Therefore, in order to obtain the pitch corresponding to the recording density, the straight line connecting the centers of the respective light emitting points of the semiconductor laser array forms an angle with the main scanning direction. Must be arranged as. In this case, the laser beam position varies or shifts due to various environmental changes, etc. Therefore, it is better to synchronize the beam position detection signal for each laser beam and the pixel clock of each laser beam for each laser beam. It is desirable that the recording position does not vary much.

Further, in Japanese Patent Laid-Open No. 57-64718, the deflection position of one laser beam among a plurality of laser beams emitted from a plurality of laser beams having known intervals in a laser beam printer is disclosed. It is described that one detector for detection and means for synchronizing other laser beams by using an output signal of this detector are provided.

Japanese Unexamined Patent Publication No. 2-42413 discloses a digital copying machine provided with a separating means for separating and outputting a laser beam for generating an image writing timing signal from a plurality of laser beams entering a beam detecting means. Is listed.

Further, n beams emitted from the light emitting portion of the recording light source are focused and imaged on n minute light spots, and an image is recorded by exposure scanning of the recording medium with these light spots. In a multi-beam recording apparatus, a light receiving element that receives at least two or more beams of the n beams within an exposure scanning range of a light spot, and the n beams are sequentially detected by an output signal of the light receiving element. Then, means for sequentially turning off the light for a predetermined time is provided so that the edge of the light receiving element on the exposure scanning start side is inclined with respect to the direction orthogonal to the exposure scanning direction.

[0014]

In the above-mentioned multi-beam recording system, it is extremely difficult to deal with the fluctuation and displacement of the laser beam position due to various environmental changes. Also,
Each laser beam is incident on the synchronization detecting light receiving element with a short time difference, and FIG. 5 shows a state of the output signal of the synchronization detecting light receiving element when the laser beams a and b are extremely overlapped. In this case, the laser beam a synchronization detection light receiving element, an output signal for the b a _1, b ₁ are combined composite signal c ₁ is obtained, a laser beam a from the composite signal c _1, detected by dividing b It is impossible to do. For this reason, it is not possible to achieve phase synchronization between the output signal of the synchronization detection light receiving element for each laser beam and the pixel clock of each laser beam.

FIG. 6 shows the state of signals when the laser beams a and b overlap by about 1/4. In this case, the output signal a ₂ for the laser beams a and b of the light receiving element for synchronization detection,
b ₂ is combined to obtain a combined signal c ₂ . Since the area S _{2 of the} combined signal c ₂ is narrow, it is difficult to have a threshold level for detecting the laser beams a and b by dividing them, and the division detection of the laser beams a and b becomes unstable.

FIG. 7 shows the state of signals when the laser beams a and b overlap each other for a very short time. In this case, the output signals a ₃ and b ₃ of the laser beams a and b of the synchronous detection light receiving element are combined to obtain a combined signal c ₃ . Since the combined signal c ₃ has a wide area S ₃ , the laser beams a and b
It becomes easy to determine the threshold level for detecting by dividing the laser beam, and it becomes possible to accurately perform the divisional detection of the laser beams a and b.

Further, in the laser beam printer described in Japanese Patent Laid-Open No. 57-64718, the deflection position of one of the laser beams emitted from the plurality of laser beams with known intervals is determined. Since the other laser beams are detected and synchronized with each other, if the interval between the laser beams changes, the synchronization depends on the deflection position detection signal for one laser beam, which causes an error or deviation. It may occur, and it is difficult to correct it.

Further, in the digital copying machine described in JP-A-2-42413, a separating means for separating and outputting a laser beam for generating an image writing timing signal from a plurality of laser beams incident on the beam detecting means is provided. Therefore, there is a drawback that a signal is erroneously detected due to an erroneous setting of the threshold level of the separating means, or the circuit is complicated and the cost is increased.

Further, in the above multi-beam recording apparatus, when the inclination between the exposure scanning start side edge of the light receiving element and the sub-scanning direction is large, or particularly when the beam diameter of the laser beam in the sub-scanning direction is large, the light receiving element is large. The temporal change in the amount of received light is reduced, and the rising waveform of the photoelectric conversion signal from the light receiving element becomes blunt. FIG. 8 shows light reception when the exposure scanning start side edge of the light receiving element is an edge Eb parallel to the sub scanning direction and when the exposure scanning start side edge of the light receiving element is an edge Ea having an angle with respect to the sub scanning direction. The waveform example of the photoelectric conversion signal from an element is shown.

In FIG. 8, PDouta shows the waveform of the photoelectric conversion signal from the light receiving element when the laser beam is incident on the exposure scanning start side edge Ea of the light receiving element, and PDoutb is the exposure scanning start side of the light receiving element with the laser beam. The waveform of the photoelectric conversion signal from the light receiving element when incident on the edge Eb is shown. As described above, the beam position detection is performed with reference to the signal obtained by binarizing the photoelectric conversion signal from the light receiving element at the threshold level. Therefore, for example, when the threshold level changes from the threshold level 1 to the threshold level 2 in FIG. When the photoelectric conversion signal from the light receiving element has a rising waveform like PDouta, a beam position error is likely to occur due to a change in the threshold level, and the beam position detection accuracy is deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multi-beam recording apparatus which is capable of remedying the above-mentioned drawbacks, capable of surely detecting the beam position, less susceptible to the influence of the beam shape, highly accurate and highly reliable. .

[0022]

In order to achieve the above-mentioned object, the invention according to claim 1 includes n (n ≧ 2) light emitting portions which are independently modulated in synchronization with a modulation clock by an image information signal. The recording light source having the recording light source is provided, and n beams emitted from the light emitting portion of the recording light source are condensed and imaged into n minute light spots, and an image is formed by exposure scanning of the recording medium by these light spots. In a multi-beam recording apparatus for recording, one or a plurality of light receiving sections are arranged within an exposure scanning range of the light spot, and each light receiving section receives at least two or more beams out of the n beams, and the light receiving section. A first means for sequentially detecting the n number of beams from the output signal of the above according to a timing signal and sequentially extinguishing the beams for a predetermined period of time, wherein the cycle of the timing signal is 1 / K (1 / K) of the cycle of the modulation clock. K ≧ 1).

According to a second aspect of the present invention, in the multi-beam recording apparatus according to the first aspect, the recording densities in the exposure scanning direction by the n beams are independently set, and the cycle of the timing signal is the n lines. It is 1 / K (K ≧ 1) of the period of the modulation clock corresponding to the minimum recording density of the recording densities in the exposure scanning direction by the beam.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the multi-beam recording apparatus described above, the phase of a plurality of beam position detection signals generated by the first means sequentially detecting the n beams by the output signal of the light receiving unit and each of the n beams A second means for substantially synchronizing the phase of the modulation clock, and a control signal for setting an image recording area with reference to one set of the plurality of beam position detection signals and each of the modulation clocks of the n beams. And a third means for generating.

The invention according to claim 4 is a reference for generating a control signal for setting an image area or the like based on the plurality of beam position detection signals in the multi-beam recording apparatus according to claim 1, 2 or 3. A fourth means for detecting a deviation between the beam position and other beam positions is provided.

The invention according to claim 5 is the invention as defined in claims 1, 2, and 3.
Alternatively, in the multi-beam recording apparatus described in 4, the recording light source is composed of a semiconductor laser array having a plurality of light emitting points that can be independently modulated in one chip.

[0027]

According to the invention described in claim 1, the light receiving section receives at least two or more beams among the n beams, and the first means sequentially outputs the n beams from the output signal of the light receiving section according to the timing signal. And sequentially turn off the lights for a predetermined time. The cycle of the timing signal is 1 / K (K ≧ 1) of the cycle of the modulation clock. Therefore, the turn-off timing of the beams becomes faster, and adjacent beams are prevented from overlapping and entering the light receiving portion. Therefore, the beam position can be reliably detected without being affected by the configuration and arrangement of the light receiving section and the beam shape, and the accuracy and reliability are increased.

According to a second aspect of the invention, in the multi-beam recording apparatus according to the first aspect, the recording density in the exposure scanning direction by the n beams is set independently, and the cycle of the timing signal is by the n beams. It is 1 / K (K ≧ 1) of the cycle of the modulation clock corresponding to the minimum recording density of the recording densities in the exposure scanning direction. Therefore, it is possible to provide a highly versatile multi-beam recording apparatus which is not affected by the change in the recording density of each beam when the recording density in the exposure scanning direction by n beams is independently set.

According to a third aspect of the present invention, in the multi-beam recording apparatus according to the first or second aspect, the first means sequentially detects n beams by the output signal of the light receiving section to generate a plurality of beams. The phase of the position detection signal and the phase of each modulation clock of the n beams are substantially synchronized by the second means, and the third means of the plurality of beam position detection signals and each modulation clock of the n beams is used. A control signal for setting the image recording area or the like is generated based on one set. Therefore, the circuit can be simplified, and the cost can be reduced, high speed and high accuracy can be achieved.

According to a fourth aspect of the present invention, in the multi-beam recording apparatus according to the first, second or third aspect, the fourth means generates a control signal for setting an image area based on a plurality of beam position detection signals. The deviation between the reference beam position and the other beam positions is detected. Therefore, it is possible to cope with the deviation of the beam position due to various factors such as a temperature rise, and it is possible to improve the reliability with high accuracy.

According to the invention of claim 5, claims 1, 2,
In the multi-beam recording apparatus described in 3 or 4, the recording light source is composed of a semiconductor laser array having a plurality of light emitting points that can be independently modulated in one chip. Therefore, it is possible to easily provide regular angles and equal intervals between the plurality of beams, and it is possible to obtain a high alignment accuracy of the plurality of beams and to realize a highly accurate multi-beam recording device.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first embodiment of the present invention, n (n ≧ 2) is independently modulated in synchronization with a modulation clock by an image information signal.
A recording light source having a light emitting portion composed of a plurality of semiconductor lasers is provided, and n laser beams emitted from the light emitting portion of the recording light source are focused and imaged on n minute light spots. In a multi-beam recording apparatus for recording an image by exposure scanning of a recording medium with spots, a light receiving element composed of a light receiving element (photoelectric conversion element) for synchronization detection that receives the n laser beams within the exposure scanning range of the light spot. And a means for sequentially detecting the n laser beams by a timing signal from the output signal of the light receiving unit and sequentially extinguishing the laser beams for a predetermined time, and the cycle of the timing signal is 1 / the cycle of the modulation clock. K (K ≧ 1).

This first embodiment is an embodiment of the invention described in claim 1, and the laser scanning optical system using the plurality of semiconductor lasers shown in FIG. 4 as a light source is used, and the plurality of semiconductor lasers are two. The semiconductor lasers are not limited to the above semiconductor lasers, and n (n ≧ 2) semiconductor lasers 17 ₁ , 17 ₂ ... Can be used. Further, after the photoconductor 22 is uniformly charged by the charging device and an electrostatic latent image is formed by exposure by the laser scanning optical system, the electrostatic latent image is developed by the developing device and transferred to the transfer paper by the transfer device. Transcribed.

FIG. 1 shows the circuit configuration of the first embodiment, and FIG.
Is a timing chart showing the operation example. The photoelectric conversion signal PDout from the light-receiving element 31 for synchronization detection is amplified by the amplifier circuit 32, binarized by the separation circuit 33 at a preset threshold level, and a plurality of semiconductor lasers 17 ₁ , 17 ₂ ... Photoelectric conversion signal PDou output from the light receiving element 31 corresponding to the laser beam of
The beam position detection signals BD ₁ , BD _2, ... Are separated from t ₁ , PDout ₂ ,. The recording device control circuit 34 for controlling the respective parts of the first embodiment uses the beam position detection signals BD ₁ , BD ₂ ... From the separation circuit 33 as a reference to synchronize the phase of the pixel clock WCLK and the semiconductor lasers 17 ₁ , 17 _2.
.. is turned on / off, recording is started, a recording area is set, and the like. In this case, each of the semiconductor lasers 17 ₁ , 17 _2, ...
A laser beam having an intensity corresponding to the image information signal is output in synchronization with the pixel clocks, and the recording device control circuit 34 determines the phase of the n pixel clocks by the beam position detection signals BD ₁ , BD _2. .. Synchronize with the falling edge of.

The separation circuit 33 binarizes the photoelectric conversion signal a from the amplifier circuit 2 at a threshold level, and outputs the binarized signal (positive logic) c from the recording device control circuit 34 to the timing signal for each main scan. Based on b (positive logic), the mask signals d, e, f ... (Positive logic) generate the semiconductor laser 17 ₁ ,
.. corresponding to the respective laser beams from 17 ₂ are masked so as to be sequentially separated, and the beam position detection signals BD ₁ , BD ₂ ... Corresponding to the respective laser beams are separated.
Here, the interval Δt of the binarized signal c is set such that the light receiving element 31 receives the next laser beam after the reception of one laser beam among the laser beams from the semiconductor lasers 17 ₁ , 17 ₂ ... It will be time to start.

When the timing signal b from the recording device control circuit 34 transits from a low level (hereinafter referred to as L) to a high reher (hereinafter referred to as H), the separation circuit 33 detects the transition and sets the mask signal d to L. To H, the position detection of the first laser beam from the semiconductor laser 17 ₁ is started. When the first laser beam scans the light receiving surface of the light receiving element 31 and the binarized signal c changes from L to H, the separation circuit 33 changes the beam position detection signal BD ₁ from H to L and the recording device control circuit 34.
Is notified of the position detection of the first laser beam.

Next, when the binarized signal c makes a transition from H to L, the separation circuit 33 detects the transition and changes the mask signal d from H to L, and at the same time sets the beam position detection signal BD ₁ to L.
To H, the position detection of the first laser beam is completed, and the mask signal e is changed from L to H to start the position detection of the second laser beam from the semiconductor laser 17 ₂ . Similarly, the second laser beam is the light receiving element 3
When the light receiving surface of No. 1 is scanned and the binarized signal c changes from L to H, the separation circuit 33 changes the beam position detection signal BD ₂ from H to L, and the recording device control circuit 34 sets the position of the second laser beam. Notify of detection.

Next, when the binarized signal c makes a transition from H to L, the separation circuit 33 detects the transition and changes the mask signal e from H to L, and at the same time sets the beam position detection signal BD ₂ to L.
By changing from H to H, the position detection of the second laser beam is ended, and the mask signal f is changed from L to H to start the position detection of the third laser beam. When the third laser beam scans the light receiving surface of the light receiving element 31 and the binarized signal c changes from L to H, the separation circuit 33 changes the beam position detection signal BD ₃ from H to L and the recording device control circuit 34. To 3
Notify the position detection of the second laser beam. In the same manner, the position of each of the other laser beams is detected to complete the detection of all the beam positions within one main scan, and the beam position detection for the next main scan is timed from the recording device control circuit 34 to the separation circuit 33. Wait until signal b is input.

FIG. 9 is a timing chart showing the operation of the first embodiment for one laser beam. In FIG. 9, WCLK is a pixel clock, OCLK is a timing signal (clock) for monitoring the presence or absence of beam position detection, P
Dout is a photoelectric conversion signal from the light receiving element 31 for synchronization detection,
BD ₁ is a beam position detection signal (negative logic) obtained by binarizing the photoelectric conversion signal PDout at a threshold level, LDon / of
f ₁ is a lighting / non-lighting control signal for the semiconductor laser 17 ₁ output from the recording device control circuit 34 (low level: semiconductor laser 17 ₁ lighting at L), and is set to K = 4, for example.

The recording device control circuit 34 controls the turning on / off of the semiconductor lasers 17 ₁ , 17 _2, ... Via the driving circuit, but the laser beam from the semiconductor laser 17 ₁ is used for LDon / off ₁ as the light receiving element 31. Immediately before being incident on the semiconductor laser 17 ₁ , the semiconductor laser 17 ₁ is turned on. When the laser beam from the semiconductor laser 17 ₁ enters the light receiving element 31 and the photoelectric conversion signal PDout from the light receiving element 31 for synchronization detection exceeds the threshold level, the beam position detection signal BD ₁ becomes L and the beam position detection is performed. Done.

The recording device control circuit 34 sets the first timing signal OCL after the beam position detection signal BD ₁ becomes L.
In synchronism with the rising edge of K, LDon / off _{1 is set} to H to turn off the semiconductor laser 17 ₁ . The beam position detection signal BD ₁ is the pixel clock W after the semiconductor laser 17 ₁ is turned off.
It becomes H in synchronization with the first rise of CLK, and the beam position detection for the laser beam from the semiconductor laser 17 ₁ is completed.

As described above, the period of the timing signal OCLK for monitoring the presence / absence of beam position detection with respect to the period of the pixel clock WCLK is shortened, and the semiconductor laser 17 is reduced.
By controlling the timing of turning off the laser beam from _1, even if the interval between adjacent laser beams is narrow,
It is possible to prevent a plurality of laser beams from simultaneously entering the light receiving surface of the light receiving element 31. For example, since K = 4 in the first embodiment, if the distance between the adjacent laser beams in the main scanning direction is larger than 1/4 of the recording pitch, the position detection of each adjacent laser beam in the main scanning direction is surely performed. It can be carried out.

Next, referring to FIG. 10, the semiconductor laser 1
7 _1, 17 laser beams 30 ₁ adjacent from _2, 30 ₂ of the position detection will be described. In FIG. 10, edges 1 to 6 are ₁ in the traveling direction of the laser beams 30 ₁ and 30 _2.
A position having an interval of / 4 dot is shown. If the laser beam 17 _second from the semiconductor laser 17 ₂ is incident on the light receiving element 31 the laser beam 30 ₁ than with the one dot of the delay from the semiconductor laser 17 _1, these laser beams 3
The power spectra of 0 ₁ and 30 ₂ are as shown in FIG. If K is set to 1, for example, the semiconductor laser 17
The laser beam 30 ₁ from ₁ is incident on the light receiving element 31, the photoelectric conversion signal PDout from the light receiving element 31 reaches the threshold level, and the laser beam 30 ₁ is about to turn off at the timing of turning off the semiconductor laser 17 _1. It takes time to move one dot. When the semiconductor laser 17 ₁ is extinguished at the timing of extinction 2, the semiconductor laser 17 ₁
The laser beam 17 ₂ from ₂ has already entered the light receiving element 31, and the light receiving element 31 for this laser beam 17 ₂
Since the photoelectric conversion signal PDout from the signal reaches the threshold level, it becomes difficult to detect the position of the laser beam 17 ₂ .

However, since K = 4 is set in the first embodiment, the laser beam 3 from the semiconductor laser 17 ₁
When 0 ₁ is incident on the light receiving element 31, the semiconductor laser 17 ₁ is turned off at the timing of extinguishing 1 after the laser beam 30 ₁ has moved by about 1/4 dot. Therefore, after the semiconductor laser 17 ₁ is turned off, the next semiconductor laser 17 ₂
The laser beam 30 ₁ has a time to move by about 3/4 dots before the laser beam 17 ₂ enters the light receiving element 31, and the position of the laser beam 30 ₂ can be reliably detected.

As described above, the period of the timing signal OCLK for controlling the turn-off timing of each laser beam in consideration of the positions of the adjacent laser beams is set to the pixel clock WC.
By setting 1 / K (K ≧ 1) of the LK cycle,
It is possible to speed up the beam turning-off timing and prevent adjacent laser beams from overlapping and entering the light receiving element 31. Therefore, the beam position of each racer beam can be reliably detected without being affected by the configuration and arrangement of the light receiving element 31 and the beam shape, and the accuracy and reliability are increased.

FIG. 11 shows a phase locked loop circuit used in the second embodiment of the present invention, and FIG. 12 is its timing chart. This second embodiment is an embodiment of the invention according to claim 2, and in the first embodiment, each laser beam 30
The recording densities in the main scanning direction by ₁ , 30 _2, ... Are independently set by a phase synchronization circuit. That is, the beam position detection signal B for the laser beam 30 ₁
Phase synchronization between D ₁ and the pixel clock WCLK ₁ is performed by the circuit shown in FIG. 11, and the beam position detection signals BD ₂ ... And the pixel clock WCL for other laser beams 30 ₂ ...
Phase synchronization with K ₂ ... Is performed by a circuit similar to the circuit shown in FIG. These circuits are the recording device control circuit 3
It is provided in 4.

The oscillator 35 outputs the reference clock CLK having a period of 1 / m of the pixel clock to the phase synchronization unit 36, and the phase synchronization unit 36 receives the beam position detection signal BD ₁ (negative logic) input from the separation circuit 33. The reset signal RESET (negative logic) that rises in synchronization with the rising edge of the reference clock CLK from the oscillator 35 immediately after the falling edge is applied to the frequency divider 37.
Output to. The frequency divider 37 divides the reference clock CLK from the oscillator 35 based on the reset signal RESET from the phase synchronization unit 36, and outputs the pixel clock WCLK ₁ .
The recording device control circuit 34 controls the turning on and off of the laser beam 30 ₁ as described above, the start of recording, the setting of a recording area, etc. in synchronization with the pixel clock WCLK ₁ from the frequency divider 37.

The phase synchronization unit 36 outputs the beam position detection signal B
When D ₁ becomes L, the reset signal RESET is made L in synchronization with the reference clock CLK from the oscillator 35 closest to the falling edge. This reset signal RESET
12 is two clocks of the reference clock CLK in FIG. 12, but it does not necessarily have to be two clocks of the reference clock CLK, and is not less than one clock of the reference clock CLK unless there are special restrictions on the circuit. It only has to have a time width. When the reset signal RESET from the phase synchronization unit 36 becomes L, the frequency divider 37 is reset in synchronization with the rising edge of the reference clock CLK from the oscillator 35 in the section where the reset signal RESET is L, and the reset signal RE
When SET becomes H, the reference clock CL from the oscillator 35
The division of K is started. Therefore, the phase synchronization of the pixel clock WCLK _{1 with} the beam position detection signal BD ₁ can be performed within the error range of 1 / m of the cycle.

In the second embodiment, the recording density in the exposure scanning direction by each laser beam is independently set by the above circuit, and the cycle of the timing signal OCLK for monitoring the presence or absence of beam position detection is set for each laser beam. 1 / K of the period of the pixel clock (pixel clock for the laser beam having the minimum recording density) WCLK corresponding to the minimum recording density of the recording densities in the exposure scanning direction
Set to (K ≧ 1). Therefore, it is possible to provide a highly versatile multi-beam recording apparatus that is not affected by changes in the recording density of each beam when the recording density in the exposure scanning direction by n beams is set independently. Also, K = m
If so, a reference clock generated by the oscillator 35 and a timing signal OCL for monitoring the presence or absence of beam position detection
K can be shared, and the circuit can be simplified.

FIG. 13 shows a phase locked loop circuit used in the third embodiment of the present invention. The third embodiment is an embodiment of the invention described in claim 2. In the phase locked loop, the oscillator 35 and the phase locked loop 36 are commonly used for each laser beam 30 ₁ , 30 _2, ... And have n frequency dividers 38 ₁ , 38 _2, ... 38 _n . Also, n pixel clocks WCL within one main scan
The laser beam 3 from the light emitting point (semiconductor lasers 17 ₁ , 17 ₂ ...) In order to perform phase synchronization of K ₁ , WCLK ₂ ...
Beam position detection signals BD ₁ , B corresponding to 0 ₁ , 30 _2, ...
D ₂ according to ... divider 38 _1, 38 ₂ each are sequentially outputs a reset signal pixel ... clock WCLK _1, WCLK ₂
A light emitting point selection unit 39 is provided so as not to adversely affect each other by the phase synchronization of ...

The laser beam 30 ₁ from the separation circuit 33,
Beam position detection signals BD ₁ , BD ₂ corresponding to 30 ₂ ...
Is input to the phase synchronization unit 36 through the OR gate 40, and the phase synchronization unit 36 outputs the reference clock from the oscillator 35 immediately after the falling edge of each beam position detection signal BD ₁ , BD ₂ ... From the OR gate 40. The reset signal RESET that rises in synchronization with the rising edge of CLK is output to the light emitting point selection unit 39.

The light emitting point selecting section 39 receives the beam position detection signal BD ₁ from the separating circuit 33 and the phase synchronizing section 3
The reset signal RESET corresponding to the beam position detection signal BD ₁ input from 6 is output to the frequency divider 38 ₁ as the reset signal RESET ₁ , and when the beam position detection signal BD ₂ is input from the separation circuit 33, the phase synchronization unit Reset signal RES corresponding to the beam position detection signal BD ₂ input from
ET is output as a reset signal RESET ₂ to the frequency divider 38 ₂ ,
Similarly, when each beam position detection signal BD ₃ ... Is input, the reset signal RESET from the phase synchronization unit 36 is output to the frequency divider 38 ₃ ... As a reset signal RESET ₃ .

The frequency dividers 38 ₁ , 38 _2, ... Divide the reference clock CLK from the oscillator 35 based on the reset signals RESET ₁ , RESET _2, ... Clocks WCLK ₁ , WCLK ₂ ... Are output, and the recording device control circuit 34 synchronizes with the laser beams 30 ₁ in synchronization with the pixel clocks WCLK ₁ , WCLK ₂ ... From the frequency dividers 38 ₁ , 38 _2. , 30 ₂ ... The above-mentioned lighting and extinction control, recording start, control of recording area setting, and the like are performed. Also, a timing signal OC for monitoring the presence or absence of beam position detection
The cycle of LK corresponds to the minimum recording density of the recording densities in the exposure scanning direction by each laser beam (pixel clock for the laser beam having the minimum recording density) 1 / K of the cycle of WCLK (K ≧ Set to 1).

In the third embodiment, all the pixel clocks WCLK ₁ , WCLK _2, ... Are generated based on the reference clock CLK from the common oscillator 35. Therefore, the pixel clocks WCLK ₁ , WCLK ₂ ,. It is possible to provide a high-quality multi-beam recording device with less variation in accuracy. Further, the period of the pixel clocks WCLK ₁ , WCLK ₂ ... Is changed for each laser beam 30 ₁ , 30 ₂ ... By changing the division ratio of each frequency divider 38 ₁ , 38 _2. It is possible to independently set the recording density in the main scanning direction for each of the laser beams 30 ₁ , 30 ₂ .
Furthermore, the cycle of the timing signal OCLK for monitoring the presence or absence of beam position detection is 1 / K (K) of the cycle of the pixel clock WCLK corresponding to the minimum recording density of the recording densities in the exposure scanning direction by each laser beam. Since it is set to ≧ 1), it is possible to provide a multi-beam recording apparatus with high versatility that is not affected by changes in the recording density of each laser beam. If K = m, the reference clock generated by the oscillator 35 and the timing signal OCLK for monitoring the presence / absence of beam position detection can be shared, and the circuit can be simplified.

A fourth embodiment of the present invention is an embodiment of the invention described in claim 3, and in the first embodiment, the phase of a plurality of beam position detection signals BD ₁ , BD _2, ... And each pixel. The phases of the clocks WCLK ₁ , WCLK _2, ...
Also, a control signal for setting the image recording area is generated based on one set of the beam position detection signals BD ₁ , BD ₂ ... And each of the pixel clocks WCLK ₁ , WCLK _2. Is.

In the fourth embodiment, the phase of a plurality of beam position detection signals BD ₁ , BD _2, ... Is generated by the same phase synchronization circuit as the second embodiment (or the same phase synchronization circuit as the third embodiment). And the phase of each pixel clock WCLK ₁ , WCLK ₂ ... Is substantially synchronized, and the beam position detection signals BD ₁ , BD ₂ ... And each pixel clock WCLK ₁ ,.
A control signal for setting an image recording area or the like is generated based on one set of WCLK ₂ ...

The recording device control circuit 34 knows a deviation of one laser beam from another laser beam corresponding to a pair of beam position detection signals which is a reference for generating a control signal for setting an image recording area. In some cases, it is possible to easily set the timing such as the recording start position and generate the control signal for setting the image recording area. FIG. 14 shows an example of setting the timing of the recording start position.

FIG. 14 shows the beam position detection signals BD ₁ and B ₁ .
Pixel clocks WCLK ₁ and WCL phase-locked to D ₂ ...
The cycle of K ₂ is the same, the beam position of the laser beam 30 ₂ is delayed by 2.5 clocks with respect to the beam position of the laser beam 30 _{1 by} the pixel clock, and the beam position of the laser beam 30 ₃ is the laser beam 30 _1. It shows that the pixel position is advanced by 2.5 clocks with respect to the beam position.
Performing recording apparatus control circuit 34 is a timing setting of the recording start position of the beam position detection signal BD ₁ and the pixel clock WCLK ₁ to the laser beam 30 ₁ as a reference.

That is, the recording device control circuit 34 starts recording by the laser beam 30 ₁ in synchronization with the rising edge a ₁ of the pixel clock WCLK ₁ after a certain period of time has elapsed since the laser beam 30 ₁ was detected. . The recording start position by the laser beam 30 ₂ is set to the laser beam 30 ₁
Pixel clock WCLK
₁ of the pixel clock WCLK the rising edge a _1
2 may be delayed by 2.5 clocks, and the phase of the pixel clock WCLK ₂ is delayed by 0.5 clocks with respect to the pixel clock WCLK ₁ . Therefore, the recording device control circuit 34 delays the pixel clock WCLK ₂ by 2 clocks with the pixel clock WCLK ₁ as a reference, sets the recording start position by the laser beam 30 _{2 at the} falling edge P _2, and records by the laser beam 30 ₂ . Pixel clock W whose start is delayed by 2.5 from the recording position by laser beam 30 _1.
The recording position by the laser beam 30 ₁ and the recording position by the laser beam 30 ₂ are matched by starting at the rising edge a ₂ of CLK ₂ .

[0060] Also, the laser beam 30 ₃ pixel clock WCLK ₃ a recording start position with respect to the rising edge a ₁ pixel clock WCLK ₁ to match the recording position by the laser beam 30 ₁ by 2.5 clock Susumere Well, the pixel clock WCLK ₃ is the pixel clock W
The phase is 0.5 clocks behind CLK ₁ . Therefore, the recording device control circuit 34 uses the pixel clock WCLK ₁
The by the pixel clock WCLK ₃ is advanced three clock phases as a reference laser beam 3 to the edge P ₃ drops its Standing
Set the recording start position by 0 _3, by the laser beam 30 ₁ by starting the recording start by the laser beam 30 ₃ on the rising edge a ₃ of the laser beam 30 _{by one} pixel clock WCLK ₃ to from 2.5 advanced recording position by The recording position and the recording position by the laser beam 30 ₃ are matched.

By doing so, the recording positions of a plurality of laser beams can be made to coincide with each other with reference to the position of one laser beam, and each pixel clock WCLK
₁ , WCLK ₂ ... are beam position detection signals BD ₁ , BD ₂ ...
The error in the recording position is reduced by synchronizing the phase with.

The recording device control circuit 34 has a control signal generator 41 as shown in FIG.
Is the pixel clock WCL from the phase synchronization circuit 42.
Control signals for controlling recording start, image recording area, etc. are generated from K ₁ , WCLK _2, ... And beam position detection signals BD ₁ , BD ₂ ,. Video part 43
Are controlled by a control signal from the control signal generator 41 to output an image signal in synchronism with the pixel clocks WCLK ₁ , WCLK ₂ ... And the semiconductor lasers 17 ₁ , 17 ₂ ... Is modulated according to the image signal of.

In the fourth embodiment, the phases of the beam position detection signals BD ₁ , BD ₂ ... And the respective pixel clocks WCLK ₁ , WCLK.
Since the phases of CLK ₂ ... Are substantially synchronized, the recording position shift in the exposure scanning direction is reduced. Further, since the control signal for controlling the recording start, the image recording area, etc. is generated by using only one set without using all the pixel clocks, the circuit can be simplified, the cost is low and the reliability is high. .

The fifth embodiment of the present invention is an embodiment of the invention described in claim 3, and in the fourth embodiment, the recording device control circuit 34 is replaced by the control signal generator 41 as shown in FIG. The control signal generator 44 is included. Beam position detection signal BD ₁ from the control signal generator 44 the phase locked loop circuit 42 pixel clock WCLK ₁ output from, WCLK ₂ ··· 1 single pixel clock WCLK ₁ and the separation circuit 33 of, BD ₂ The control signal for controlling the recording start, the image recording area, and the like is generated from the ... And output to the video unit 43. Therefore, similar to the fourth embodiment, the recording position deviation in the exposure scanning direction is small, the circuit can be simplified, and the cost is low and the reliability is high.

FIG. 17 shows a beam position deviation detecting circuit of the sixth embodiment of the present invention, and FIG. 18 shows its timing chart. The sixth embodiment is an embodiment of the invention described in claim 4, and in the above embodiment, a beam position deviation detection circuit is provided. This beam position deviation detection circuit detects deviations of other beam positions with reference to the beam position detected first after the start of main scanning, and a counter 45 for counting the number of beams, and after the start of main scanning. Of the counter 46, which is reset to 0 by the first beam position detection signal BD ₁ for counting the pixel clock WCLK ₁ , and the address of the counter 46 at the time of detecting the positions of the second and subsequent laser beams 30 _2. A buffer 47 for storing positional deviation data, a counter 45,
It has flip-flops 48, 49 and 50 for generating control signals for the buffer 46 and the buffer 47.

The counter 45 receives the count enable signal / EN from the flip-flop 50, and the buffer 47 receives the write enable signal / WE from the flip-flop 49. A data read permission signal / RE is input to the buffer 47 from the recording device control circuit 34.
All signals except the pixel clock WCLK ₁ are negative logic.

After the main scanning is started, the beam position detection signal BD ₁ from the separation circuit 33 is input to the counters 45 and 46 as a reset signal to reset the counters 45 and 46, and the counter 46 starts counting the pixel clock WCLK _1. To do. The flip-flop 48 is the separation circuit 33.
Beam position detection signals BD ₁ , BD ₂ , BD ₃ from the above are input via an OR circuit 51, and the pixel clock WCLK ₁
At the rising edge of, the output signal of the OR circuit 51 is latched.

The NOR circuit 52 receives the output signal of the OR circuit 51 and the non-inverted output signal of the flip-flop 48,
When the output signal of the OR circuit 51 is L and the non-inverted output signal of the flip-flop 48 is H, the output signal becomes H. The flip-flop 50 latches the output signal of the NOR circuit 52 at the rising edge of the pixel clock WCLK ₁ and outputs the non-inverted output signal to the counter 45 as the count enable signal / EN. Therefore, the count enable signal / EN becomes L each time each of the beam position detection signals BD ₁ , BD ₂ , BD ₃ is input to the OR circuit 51, and allows the counter 45 to count, and the counter 45 causes the laser beam 30 ₁ , 30 ₂ , 30
Each time position detection ₃ is performed, the pixel clock WCLK _{1 is} incremented by one.

The inverted output signal of the flip-flop 48 and the output signal of the OR circuit 51 are input to the NOR circuit 53, and the flip-flop 49 causes the pixel clock WCLK.
_At the rising edge of ₁ , the output signal of the NOR circuit 53 is latched. When the count enable signal / EN becomes L, the write enable signal / WE from the flip-flop 49 becomes L with a delay of one clock with the pixel clock WCLK ₁ , and the buffer 47 receives the address (laser beam 30 specified by the counter 45). ₍ Addresses corresponding to ₁ , 30 ₂ , and 30 ₃ ), the count content of the counter 46, that is, the pixel clock WCL
Beam position deviation data of each laser beam in units of K ₁ is stored.

The recording device control circuit 34 retrieves the positional deviation data from the buffer 47 as needed, and the positional deviation data and the beam position detection signals BD ₁ and BD _{2 are} read.
, And each pixel clock WCLK ₁ , WCLK _2, ... (Or one set of them) are used as a reference to generate a control signal for setting an image recording area. In this case, the recording device control circuit 34
Is based on the beam position detection signals BD ₁ , BD ₂ ... And each pixel clock WCLK ₁ , WCLK ₂ ... (Or one set thereof), and corrects the beam position deviation by correcting the position deviation data. I do. Therefore, it is not affected by the beam position change over time due to environmental changes and the like, and the reliability is improved.

In the sixth embodiment, the beam position shift detection circuit detects the position shift of each laser beam and the recording device control circuit 34 corrects the position shift of each laser beam, so that various factors such as temperature rise are caused. It is possible to cope with the fluctuation of the beam position detection signal due to the above, and the reliability is improved.

In another embodiment of the present invention, in each of the above embodiments, a plurality of light emitting portions capable of being independently modulated according to an image signal in place of the plurality of semiconductor lasers 17 ₁ , 17 ₂ ... The semiconductor laser array contained therein was used. In this embodiment, since the beams are fixed at a constant pitch in the semiconductor laser array, it is possible to easily provide a regular angle and an equal interval between the plurality of beams, and to improve the alignment accuracy of the plurality of beams. A highly accurate multi-beam recording apparatus can be realized.

[0073]

As described above, according to the first aspect of the present invention, there is provided a recording light source having n (n ≧ 2) light emitting portions which are independently modulated in synchronization with a modulation clock by an image information signal. A multi-beam system that includes n beams emitted from the light emitting portion of the recording light source, focuses and forms an image on n minute light spots, and records an image by scanning the exposure of the recording medium with these light spots. In the recording apparatus, one or a plurality of light receiving sections are arranged within the exposure scanning range of the light spot, each of which receives at least two or more beams of the n beams, and a timing based on an output signal of the light receiving section. A first means for sequentially detecting the n beams by a signal and sequentially extinguishing them for a predetermined time, and the cycle of the timing signal is 1 / K (K) of the cycle of the modulation clock.
Since ≧ 1), the turning-off timing of the beams becomes faster, and it is possible to prevent adjacent beams from overlapping and entering the light receiving portion. Therefore, the beam position can be reliably detected without being affected by the configuration and arrangement of the light receiving section and the beam shape, and the accuracy and reliability are increased.

According to a second aspect of the present invention, in the multi-beam recording apparatus according to the first aspect, the recording densities in the exposure scanning direction by the n beams are independently set, and the cycle of the timing signal is the n. Since the recording density in the exposure scanning direction by the n beams is set to 1 / K (K ≧ 1) of the cycle of the modulation clock corresponding to the minimum recording density in the exposure scanning direction by the n beams, the recording density in the exposure scanning direction by the n beams is independent. It is possible to provide a highly versatile multi-beam recording apparatus that is not affected by changes in the recording density of each beam when set to.

According to the invention described in claim 3, in the multi-beam recording apparatus according to claim 1 or 2,
Second means substantially synchronizes the phases of a plurality of beam position detection signals generated by sequentially detecting the n beams with the output signal of the light receiving section and the phases of the respective modulation clocks of the n beams. And a third means for generating a control signal for setting an image recording area or the like with reference to one set of the plurality of beam position detection signals and each of the modulated clocks of the n beams. The circuit can be simplified, and the cost can be reduced, high speed and high accuracy can be achieved.

According to the invention described in claim 4,
In the multi-beam recording device described in 2 or 3, a deviation between a beam position which is a reference for generating a control signal for setting an image area based on the plurality of beam position detection signals and a beam position other than that is detected. Since the fourth means is provided, it is possible to cope with the deviation of the beam position due to various factors such as temperature rise, and it is possible to increase the accuracy and reliability.

According to the invention of claim 5, claim 1,
In the multi-beam recording device according to 2, 3, or 4,
Since the recording light source is composed of a semiconductor laser array having a plurality of light emitting points that can be independently modulated in one chip, it is possible to easily provide regular angles and equal intervals between a plurality of beams. Therefore, it is possible to obtain a high precision of arrangement of a plurality of beams and to realize a high precision multi-beam recording apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a first embodiment of the present invention.

FIG. 2 is a timing chart showing an operation example of the first embodiment.

FIG. 3 is a perspective view showing an example of a laser optical system used in a laser printer.

FIG. 4 is a front view showing an example of a laser scanning optical system using as a light source a plurality of semiconductor lasers used in a multi-beam recording method.

FIG. 5 is a waveform diagram showing a state of an output signal of the synchronous detection light receiving element when the laser beams are extremely overlapped with each other in the laser scanning optical system.

FIG. 6 is a waveform diagram showing a state of a signal when laser beams overlap by about ¼ in the laser scanning optical system.

FIG. 7 is a waveform diagram showing a state of signals when laser beams overlap with each other in a minute time in the same laser scanning optical system.

FIG. 8 is a waveform diagram showing a waveform example of a photoelectric conversion signal from a light receiving element in a conventional device.

FIG. 9 is a timing chart showing the operation of the first embodiment.

FIG. 10 is a diagram for explaining the first embodiment.

FIG. 11 is a block diagram showing a phase locked loop circuit used in a second embodiment of the present invention.

FIG. 12 is a timing chart of the same phase locked loop circuit.

FIG. 13 is a block diagram showing a phase locked loop circuit used in a third embodiment of the present invention.

FIG. 14 is a timing chart showing an example of setting the timing of the recording start position in the fourth embodiment of the present invention.

FIG. 15 is a block diagram showing a part of the fourth embodiment.

FIG. 16 is a block diagram showing a part of a fifth embodiment of the present invention.

FIG. 17 is a block diagram showing a beam position deviation detecting circuit according to a sixth embodiment of the present invention.

FIG. 18 is a timing chart of the beam position shift detection circuit.

[Explanation of symbols]

 31 light receiving element 33 separation circuit 34 recording device control circuit

Claims (5)

[Claims] 1. A recording light source having n (n ≧ 2) light emitting portions independently modulated in synchronization with a modulation clock by an image information signal, and n emitted from the light emitting portion of the recording light source. In a multi-beam recording apparatus for focusing an image of a book beam on n minute light spots and recording an image by exposure scanning of a recording medium with these light spots, 1 A light-receiving unit, in which a plurality of or a plurality of beams are arranged, each of which receives at least two beams out of the n-beams, and the n-beams are sequentially detected from the output signal of the light-receiving unit according to a timing signal and sequentially And a first means for turning off the light for a predetermined time,
A multi-beam recording apparatus, wherein the cycle of the timing signal is 1 / K (K ≧ 1) of the cycle of the modulation clock. 2. The multi-beam recording apparatus according to claim 1, wherein the recording densities in the exposure scanning direction by the n beams are independently set, and the cycle of the timing signal is in the exposure scanning direction by the n beams. 1 / K of the period of the modulation clock corresponding to the minimum recording density of the recording densities (K ≧
1) A multi-beam recording device characterized in that 3. A multi-beam recording apparatus according to claim 1, wherein the first means sequentially detects the n beams by the output signal of the light receiving section and generates a plurality of beam position detection signals. Means for substantially synchronizing the phase of each of the modulation clocks of the n beams with one another of the plurality of beam position detection signals and each of the modulation clocks of the n beams. And a third means for generating a control signal for setting an image recording area and the like. 4. The multi-beam recording apparatus according to claim 1, wherein a beam position serving as a reference for generating a control signal for setting an image area based on the plurality of beam position detection signals, and other beam positions. A multi-beam recording apparatus comprising a fourth means for detecting a deviation from the beam position of the. 5. The multi-beam recording apparatus according to claim 1, 2, 3 or 4, wherein the recording light source is constituted by a semiconductor laser array having a plurality of light emitting points which can be independently modulated in one chip. Characteristic multi-beam recording device.