JPH0366036A - Light scanning record device - Google Patents

Abstract

PURPOSE:To facilitate adjustment and to make a device inexpensive by equipping a means driving a converging lens and a means storing the optimum positional data of the converging lens corresponding to the polarizing angle of a reflection deflecting mirror and performing the converging motion of an optical beam electrically. CONSTITUTION:The optical beam 3 emitted from a semiconductor laser 1 is made a parallel beam by a collimator lens 2 and made incident on a converging lens 11. Moreover the optical beam 3 is made incident on a galvanomirror 12 and polarized with its reflection, reflected further by a longsized mirror 6 and executes a main scanning in an arrow mark X direction on a sensitive film 7. At the same time the film 7 is transferred in the arrow mark Y direction almost orthogonal with the main scanning direction X by the endless belt 8 driven by a driving device 9, a sub-scanning is executed and the optical beam 3 is two-dimensionally radiated on the film 7. The laser 1 is then subjected to ON-OFF control based on a digital image signal S like corresponding to a stored image by a control device 10 and a recording image is formed. The device is made inexpensive and the adjustment becomes easy because of the converging motion of the optical beam being performed electrically.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an optical scanning recording device that records an image by scanning an irradiated object with a deflected light beam using a rotatable mirror. .

[Conventional technology]

FIG. 7 is a diagram showing a conventional optical scanning recording device disclosed in, for example, Japanese Unexamined Patent Publication No. 63-167559. Collimator lens 3 is the light beam emitted from the semiconductor laser l, 4 is the light beam 3
A rotating polygon mirror 5 is a rotating polygon mirror 5 having a characteristic that the focal point position is proportional to the deflected angle.
A focusing lens consisting of a θ lens; 6 a long mirror for reflecting the light from the focusing lens 5 consisting of an f/θ lens at a predetermined angle; 7 a photosensitive film; 8 an endless belt for transporting the photosensitive film 7; 9 is a drive device for driving the endless belt 8, and 10 is a control device for controlling ON-OFF of the semiconductor laser 1.

Next, the operation will be explained.

A light beam 3 emitted from a semiconductor laser 1 is made into a parallel beam by a collimator lens 2 and then passed through a rotating polygon mirror 4.
incident on . The light beam 3 is reflected and deflected by the rotating polygon mirror 4, passes through a focusing lens 5 consisting of an f/θ lens, is reflected by a long mirror 6, and scans the photosensitive film 7 in the direction of arrow X (main scanning). At the same time, the photosensitive film 7 is conveyed by the endless belt 8 driven by the drive device 9 in the direction of the arrow Y, which is substantially perpendicular to the main scanning direction X, and sub-scanning is performed.
A light beam 3 is two-dimensionally irradiated onto the top. Then, the semiconductor laser 1 is controlled by the control device 10 to control the digital signal image signal S.
Based on 0N-OFF! ! ]? III, whereby the light beam 3 is pulse number modulated. Therefore, an image based on the image signal S is recorded on the photosensitive film 7.

[Problem to be solved by the invention]

Conventional optical scanning recording devices are configured as described above, so expensive optical components such as f/theta lenses must be used, and strict optical adjustments such as adjustment of the f/theta lenses are required. In addition, f/theta lenses are usually used in combination with multiple lenses, so they have a large volume and weight.
There have been problems in that the accuracy of the recorded image is largely determined by the accuracy of the optical components.

This invention was made to solve the above-mentioned problems, and it is possible to reduce the volume and weight of the optical device, and also eliminates the need to use expensive optical components such as f/θ lenses. A further object of the present invention is to obtain an optical scanning recording device that can be electrically adjusted from the outside.

[Means to solve the problem]

The optical scanning recording device according to the present invention includes means for driving a condensing lens and means for storing optimum position data of the condensing lens corresponding to the deflection angle of the reflective deflection mirror, and the condensing lens is positioned at the optimum position. The driving means is driven while referring to the storage means in accordance with the deflection angle of the reflecting deflection mirror so as to obtain the deflection angle of the reflecting deflection mirror.

[Effect]

The optical scanning recording device according to the present invention stores in advance the position of the condenser lens with respect to the deflection angle of the reflective deflection mirror, and drives the condenser lens by referring to the optimum position data of the condenser lens, thereby optimizing the condensing position. become

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a semiconductor laser, 2 is a collimator lens for collimating the light emitted from the semiconductor laser l, 11 is a condenser lens for converging the parallel light from the collimator lens 2, and 3 is a semiconductor laser. 1 is a galvanometer mirror that reflects and deflects the light beam 3; 17 is a photosensitive film; 6 is a long mirror for reflecting the light onto the photosensitive film 7; 8 is a conveyor for transporting the photosensitive film 7. Endless belt; 9 is a drive device for driving the endless belt 8; IO is 0N- of the semiconductor laser 1;
This is a control device that controls OFF.

The operation of the above embodiment will be explained below.

A light beam 3 emitted from a semiconductor laser 1 is made into a parallel beam by a collimator lens 2 and then passed through a condenser lens 1.
1. The light beam 3 that has passed through the condensing lens 11 is incident on the galvanometer mirror 12, is reflected and deflected, and is further reflected on the elongated mirror 6, thereby scanning the photosensitive film 7 in the direction of the arrow X (main scanning). At the same time, the photosensitive film 7 is conveyed by the endless belt 8 driven by the drive device 9 in the direction of the arrow Y, which is substantially perpendicular to the main scanning direction X, and sub-scanning is performed. It is irradiated two-dimensionally. Then, the semiconductor laser 1 is controlled ON-OFF by the control device 10 based on the digital image signal S corresponding to the recorded image, and the recorded image is formed.

Next, FIGS. 2 and 3 show the above-mentioned light condensing operation in detail.

Based on FIG. 4, a method of focusing the light beam 3 will be explained in detail.

In FIG. 2, 11 is a condensing lens, 13 is a slider that holds the condensing lens 11 and moves to any position within the movable range of δl, and 14a and 14b are guide rails that guide the slider 13 in a predetermined direction. A and guide rail B
15 is a magnet 16 which is a coil, and these constitute a linear motor 17.

In FIG. 4, reference numeral 24 is a condenser lens position memory that stores position data of the condenser lens 11 corresponding to the deflection amount of the galvanometer 12, and 20 is a condenser lens position memory that stores position data from the condenser lens position memory 24 and a near motor 17. 21 is a D/A converter that converts the output from the comparator 20 into D/A, and 22 amplifies the output of the D/A converter 21. These amplifiers constitute the condensing lens movement signal generating section.

23 is a linear motor drive circuit for driving the linear motor 17.

In Fig. 3, a light beam 3 is
When the light beam 3 is reflected and deflected, the focal point position of the light beam 3 is distributed on an arc FC having a radius l and centered on the point where the light beam 3 enters the galvanometer mirror 12. In this case, the light beam 3 is focused at the point O on the photosensitive film 7 (hereinafter referred to as focusing), but not focused at the point P. Therefore, the light beam 3 is focused at the point P. Condensing lens 1
1 can be brought into focus by moving the condenser lens 11 in the direction closer to the photosensitive film 7 by the difference δl between the point P on the photosensitive film 7 and the point P' on the arc FC where the focusing positions are distributed. Possible 0 e.g. l=400mm, h/2-1
08mm, θ-15,1", δlζ7.1
It will be 6mm. Therefore, in this case, it is sufficient to bring the condensing lens 11 close to the photosensitive film 7 by about 7.16 mm.As in this example, the movement amount δl is determined as δ2-2·(1/cosθ-1), and the linear motor 17 is given as the amount of movement. Therefore, this movement amount δl with respect to θ that changes every moment
The light beam 3 can be focused on the photosensitive film 7 by converting it into electric power to be applied to the linear motor 17 in synchronization with the deflection angle θ of the galvano mirror 12.

FIG. 4 shows an example of a galvanometer mirror 12 in which a condensing lens movement signal generating section 18 is provided to drive a linear motor 7.
The position of the condenser lens 11 corresponding to the deflection angle (hereinafter referred to as an appropriate position) is obtained by referring to the condenser lens position memory 24.

Proper position and position detection unit of linear motor 7 (not shown)
The comparator A20 compares the information on the condensing lens position obtained from the comparator A20 to obtain a comparison value. The D/A converter 21 uses this comparison value.
．． After applying a predetermined operation using the amplifier 22, the linear motor 7 is supplied to the linear motor drive circuit No. 2.
is driven, the slider 13 is moved, and the condenser lens 11 is always held at an appropriate position. In this method, the scanning linear velocity of the light beam 3 in the main scanning direction
The velocity is proportional to the deflection angular velocity by 12.

On the other hand, the light beam 3 is deflected using a galvanometer mirror 12 and scanned onto the photosensitive film 7 (hereinafter referred to as deflection scanning).
In this case, one pixel row (hereinafter referred to as a main scanning line) is recorded by one deflection scan at 124 of the galvano mirror.
Two main scanning lines are recorded during one reciprocating section of 12.

The operation in this case will be explained below with reference to FIGS. 5 and 6. FIG. 5(a) shows the operating state of the galvano mirror 12, and the linear motor 17 operates as shown in FIG. 5(b) corresponding to the deflection angle of the galvano mirror 12. Fifth
In the figure, no image recording operation is performed in the PF section.

FIG. 6(a) shows the scanning state of the light beam 3 when the photosensitive film 7 is conveyed continuously at a speed V in the sub-scanning direction Y. At this time, the scanning state of the light beam 3 in the main scanning direction Since the scan direction Y moves simultaneously, the trajectory of the Nth main scanning line (hereinafter referred to as N main scanning line) and the N+1st main scanning line (hereinafter referred to as N+1 main scanning line) becomes a zigzag shape.

Therefore, if the photosensitive film 7 can be transported by driving the drive device 9 only in the PF section shown in FIG.
The 0 image signal S that can obtain a trajectory in which the interval between the N main scanning line and the N+1 main scanning line is the transport amount δy of the photosensitive film 7 as shown in FIG. 5(d) is shown in FIG. 5(d). is applied to the control device 10 outside the PF section.

In the above embodiment, the movement amount δl is given by referring to the condensing lens position memory 24, but it is also possible to give driving power to the linear motor 17 using an electric circuit having the above characteristics.

Further, in the above embodiment, the linear motor 17 is used to move the condensing lens 11, but other electromagnetic means for moving the condensing lens 11, such as a voice coil, may be used.

In addition, although the galvanometer mirror 12 is used as the deflection means for the light beam 3 on the private stream side, for example, a rotating polygon mirror may be used as other reflective deflection means. In this case,
The focal length changes because the incident position of the light beam 3 moves according to the rotation of ξ, but by correcting the data in the condenser lens position memory 24 in consideration of the correction needle, the condensing position can always be adjusted appropriately. can be kept.

Further, in the above embodiment, the photosensitive film 7 is used as the object to be irradiated with the light beam 3, but other objects to be irradiated may be, for example, a photosensitive drum that forms an electrostatic latent image by irradiation with the light beam 3. However, it is not necessarily limited to the photosensitive film 7.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a means for driving a condenser lens and a means for storing optimum position data of the condenser lens corresponding to the deflection angle of the reflective deflection mirror, and the condensing operation of the light beam is performed. Since this is configured to be performed electrically, the device can be made inexpensive, easy to adjust, and the device volume can be reduced. Further, there is an effect that the accuracy of recorded image quality can be determined electrically.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an optical scanning recording device according to an embodiment of the present invention, FIG. 2 is a diagram showing a near motor for driving a condensing lens, and FIG. 3 is a diagram illustrating the amount of movement of the condensing lens. Fourth
The figure shows the condenser lens movement signal generator, Figure 5 shows the operating status of the galvano mirror and linear motor, and the PF section, Figure 6 shows the scanning locus of the light beam, and Figure 7 shows the conventional 1 is a diagram showing an optical scanning recording device of FIG. 1 is a semiconductor laser, 2 is a collimator lens, 3 is a light beam, 6 is a long ξ beam, 7 is a photosensitive film, 8 is an endless belt, 9 is a driving device, 11 is a condensing lens, 12 is a galvanometer. 18 is a condensing lens movement signal generating section; 20
2 is a comparator, 21 is a D/A converter, and 22 is a linear motor drive circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A semiconductor laser, a collimator lens that converts the light beam emitted from the semiconductor laser into parallel light, a condenser lens that focuses the light beam emitted from the semiconductor laser, and a reflective deflection mirror that deflects the light beam. scanning means; and a driving means for moving the condensing lens to a position corresponding to the deflection angle of the reflective deflection mirror, and the driving means for driving the condensing lens is configured to perform scanning using the previously created Optical scanning recording is performed by referring to position data of the condenser lens according to the deflection angle of the reflection deflection mirror based on position data of the condenser lens corresponding to the deflection angle of the reflection deflection mirror. Device.