JPH0488311A - Position adjusting mechanism for scanner - Google Patents

Abstract

PURPOSE:To accurately and efficiently adjust the inclination of an optical deflector by providing a spherical part which is provided on one end side of the optical deflector and a pressing means which presses the other end side from biaxial directions intersecting with each other and adjusts the angle position of the optical deflector. CONSTITUTION:This mechanism has the spherical part 32 which is provided on one end side of the optical deflector 20, a holder 34 which has circular optical parts 44, 46 in contact with the spherical part 32 and can rotate and fix the spherical part 32 and the pressing means 36 which presses the other end side of the optical deflector 20 from the biaxial directions intersecting with each other and adjusts the angle position of the optical deflector 20. Then, the spherical part 32 provided on one end side of the optical deflector 20 is held rotatably with the holder 34 and thereafter, the other end side of this optical deflector 20 is pressed by means of the pressing means 36 from the biaxial directions intersecting with each other, by which the angle position of the optical deflector 20 is adjusted. Further, the spherical part 32 is fixed at a desired angle by the holder 34. The inclination of the optical deflector 20 is thus corrected with good accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a scanning device for correcting the inclination of an optical deflector that scans a light beam onto a scanned object [Background of the Invention] Printing, plate making, etc. In the field of , image scanning reading and reproducing systems that electrically process image information carried on a manuscript to create a film master have been widely adopted for the purpose of streamlining work processes and improving image quality.

In this image scanning reading and reproducing system, an optical deflector is used to cause a light beam to perform main scanning on an object to be scanned, such as a document or a record carrier that is conveyed in a sub-scanning direction. This optical deflector has a deflection mirror that vibrates at high speed via a rotating shaft, and the light beam is deflected by the deflection mirror to main-scan the object to be scanned.

By the way, the optical deflector may be tilted with respect to the coordinate system of the system at the time of setting. Furthermore, the mirror rotation axis or the deflection mirror may be tilted in advance due to errors in manufacturing the optical deflector itself. In this case, the trajectory of the light beam scanning the object to be scanned is not only shifted in the sub-scanning direction, but also curved or tilted.

Therefore, the present applicant has developed a method for adjusting the inclination of a surface mirror type optical deflector, or the mirror rotation axis of this optical deflector and/or the inclination of a deflection mirror, to the amount of curvature, the amount of inclination, etc. of the scanning line on the object to be scanned. By performing correction based on the scanning beam, it is possible to obtain an accurate scanning beam trajectory free from curvature, inclination, etc., and also to improve the yield of the optical deflector and to provide an inexpensive device. A trajectory correction method has been proposed (see Japanese Patent Laid-Open No. 2-64521).

[Problems to be Solved by the Invention] By the way, as for a mechanism for carrying out the above correction method, only a mechanism using thin foil has been disclosed. For this reason,
When actually adjusting the inclination or the like of the optical deflector, there are problems in that the adjustment work becomes complicated and it becomes difficult to perform the adjustment work with high precision.

The present invention was made in order to solve this type of problem, and it is an object of the present invention to provide a position adjustment mechanism for a scanning device that can accurately and efficiently perform the tilt adjustment work of an optical deflector. purpose.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a scanning device in which an optical deflector for scanning a light beam onto a scanned object is disposed, in which one end side of the optical deflector is disposed. A spherical part provided, a holder having a conical part in contact with the spherical part and capable of rotating and fixing the spherical part, and the other end side of the optical deflector are pressed from biaxial directions intersecting with each other. It is characterized by comprising a pressing means for adjusting the angular position of the optical deflector.

[Operation] In the position adjustment mechanism of the scanning device configured as described above,
After the spherical part provided at one end of the optical deflector is made rotatable relative to the holder, the other end of the optical deflector is pressed from two axes directions intersecting each other via a pressing means. The angular position of the optical deflector is adjusted. moreover,
The spherical part is fixed at a desired angle by the holder, and the tilt correction of the optical deflector is performed with high precision.

[Embodiments] An embodiment of the position adjustment mechanism of a scanning device according to the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates the main body of an image reproduction device f (scanning device) in which the position adjustment mechanism according to the present embodiment is incorporated. This main body 10 includes a laser diode 12 that outputs a recording laser beam L1, and a synchronization laser beam L2.
It has a laser diode 14 that outputs. The recording laser beam L1 output from the laser diode 12 is guided to a single-mirror optical deflector 20 via a collimator 16.
Synchronization laser light L output from the laser diode 14
2 is guided to this optical deflector 20 via a collimator 22.

As shown in FIG. 2, the optical deflector 20 includes a drive section 26 housed in the main body 24, a mirror rotation shaft 28 that is rotated at high speed by the drive section 26, and a mirror rotation shaft 28 that is attached to the mirror rotation shaft 28. The main body 24 includes a deflection mirror 30 that vibrates in the direction of the arrow in FIG.

This spherical portion 32, holder 34, and pressing means 36 constitute a position adjustment mechanism 38 according to this embodiment.

As shown in FIGS. 1 and 2, the holder 34 includes a fixed base 40 and a mounting base 42, and the fixed base 40 and the mounting base 42 are capable of rotating and fixing the spherical part 32 in contact with the spherical part 32. Conical portions 44 and 46 are provided, and the mounting base 42 is fixed to the fixed base 40 via bolts 48.

The suppressing means 36 includes micrometers 52a and 52b that are attached to bases 50a and 50b and press the main body 24 of the optical deflector 20 in two axes (X-axis and Y-axis) that intersect with each other. , 52b to spindle 5
4a and 54b protrude.

The recording laser beam L1 incident on the deflection mirror 30 of the optical deflector 20 is aligned with the mirror rotation axis 28 with respect to the synchronization laser beam L2.
The beam is set so that it is incident at a predetermined angle α in the axial direction.

The recording laser beam L1 reflected and deflected by the optical deflector 20 enters the reflection mirror 58 via the fθ lens 56, and then is deflected upward by approximately 90° and main-scans the film F in the direction of arrow A. (See Figure 3). This film F is attached to a drum 60 and a pair of nip rollers 62a and 62b.
It is configured to be conveyed in the sub-scanning direction in the direction of arrow B while being held between them.

Synchronization laser beam L reflected and deflected by optical deflector 20
2 is guided through an fθ lens 56 to a reference grating plate 64 for generating a synchronization signal.

A large number of slits 66 are formed in the reference grating plate 64 along the main scanning direction (arrow A direction), and the synchronizing laser beam L2 that has passed through the slits 66 is emitted onto the back surface of the reference grating plate 64. A condensing rod 68 is provided to condense light, and photoelectric conversion elements 70a and 70b, which are composed of PIN photodiodes and the like, are attached to both ends of the condensing rod 68, which convert the synchronizing laser beam L2 into an electrical signal. .

The position adjustment mechanism of the scanning device according to this embodiment is constructed as described above, and its operation will be explained next.

When the laser diode 14 is driven, the synchronizing laser beam L2 output from the laser diode 14 is converted into a parallel beam by the collimator 22 and then sent to the optical deflector 20.
incident on . In this optical deflector 20, a deflection mirror 30 is vibrated at high speed in the direction of the arrow.
The synchronizing laser beam L2 reflected by the fθ lens 5
6 to a reference grid plate 64, and this reference grid plate 6
4 Scan above. In this case, a large number of slits 66 are formed in the reference grating plate 64, and the synchronizing laser beam L2 that has passed through the slits 66 enters the condensing rod 68 as a pulsed optical signal, and then enters the condensing rod 68 by its inner surface. The light is repeatedly reflected and guided to photoelectric conversion elements 70a and 70b.

The photoelectric conversion elements 70a and 70b convert the optical signal into an electrical signal, and after this electrical signal is multiplied to a predetermined frequency, it is supplied as a synchronization signal for controlling the laser diode 120.

On the other hand, the laser diode 12 emits eight recording laser beams L1 modulated according to image information based on the synchronization signal. This recording laser beam L1 is made into a parallel beam by the collimator 16, and then enters the optical deflector 20. A deflection mirror 30 constituting this optical deflector 20 reflects and deflects the recording laser beam L1, and guides it onto the film F via an fθ lens 56 and a reflection mirror 58. At that time, film F
is conveyed in the sub-scanning direction in the direction of arrow B while being sandwiched between the drum 60 and nip rollers 62a and 62b.
An image is formed two-dimensionally on the film F by the recording laser beam L1 that main scans in the direction of the arrow A.

Here, the mirror rotation axis 28 or the deflection mirror 30 constituting the optical deflector 20 is set parallel to the coordinate system constituting the main body 10, for example, the two axes of the xYZ coordinate system shown in FIG. If not, the scanning line 80 of the recording laser beam L1 that main scans the film F will be displaced in the Z'-axis direction, or the scanning line 80 will be curved, tilted, etc.

In this case, in this embodiment, the curvature of the scanning beam locus of the recording laser beam L1 on the film F is
This is corrected by tilting the main body 24 in a predetermined direction.

That is, first, an xYZ coordinate system is set for the main body 24 as shown in FIG. 4a. Here, Z of the main body 24
The inclination angle around the X axis with respect to the axis is ex (see Figure 4),
The inclination angle around the Y axis with respect to the Z axis is θy (see Figure 4 C)
shall be.

On the other hand, Fig. 5a shows a case where the trajectory of the scanning beam is curved, and this case is defined as BOW (curved). Indicates the case where it is tilted, and this case is defined as LEAN (tilt).

Therefore, the relationship between ex1θy, BOW, and LEAN is obtained. Here, M is a 2×2 coefficient matrix specific to the image reproduction device shown in FIG.

The spindles 5 of the micrometers 52a and 52b are connected from the center of rotation of the main body 240 of the optical deflector 20 to the spherical part 320.
4a, 54b, the movement amounts ΔX, Δy of the spindles 54a, 54b can be determined from ΔX=)(xey Δy=−HX Ox.

When each movement amount ΔX, Δy is set in this way, first, the mounting base 42 constituting the holder 34 is loosened via the bolt 48, and then the micrometers 52a, 52b are operated and the spindles 54a, 54b are is the predetermined movement amount Δ
y, is displaced by ΔX. As a result, the main body 24 of the optical deflector 20 is tilted with the center of the spherical portion 32 as a fulcrum,
Next, by tightening the bolt 48, the mounting base 42 is fixed to the fixed base 40, and the main body 24 is held in its inclined position.

As described above, in this embodiment, when the bolt 48 is loosened, the spherical part 32 provided on one end side of the main body 24 moves into each conical part 4 of the fixing base 40 and the mounting base 42 that constitute the holder 34.
4.46 and can be rotated in various directions.

Each spindle 5 in contact with the other end side of the main body 24
By moving 4a and 54b forward and backward, the main body 24 can be easily and accurately tilted in a desired direction using the spherical portion 32 as a fulcrum. Therefore, if the mounting base 42 is fixed to the fixed base 40 via the bolt 48, the conical portion 44.46
presses against the spherical portion 32, and the main body 24 is reliably held in the above-mentioned position.

This provides the effect that the position adjustment work of the optical deflector 20 can be performed efficiently and with high precision.

In this embodiment, the micrometers 52a and 52b constituting the pressing means 36 are arranged to be oriented in the optical axis direction of the fθ lens 56 and in a direction perpendicular thereto.
It is also possible to set the arrangement position as shown in FIG.

That is, the micrometers 52a and 52b are arranged to be perpendicular to each other and oriented in a direction perpendicular to a direction parallel to the reflective surface of the deflection mirror 30.

Therefore, M in equation (1) is selected as a predetermined coefficient matrix M1,
Similarly, the position adjustment work of the optical deflector 20 may be performed.

[Effects of the Invention] The position adjustment mechanism for a scanning device according to the present invention configured as described above has the following effects and advantages.

The spherical part provided at one end of the optical deflector is rotatably supported by the holder, and the other end of the optical deflector is pressed from two axes directions that intersect with each other via a pressing means. The optical deflector is easily and accurately adjusted to the desired angular position. Therefore, the mounting angle of the optical deflector can be corrected with high precision based on the correction amount obtained by calculation, and the locus of the scanning beam can be made linear.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an image reproducing device to which a position adjustment mechanism according to the present invention is applied, FIG. 2 is an explanatory side view of the position adjustment mechanism, and FIG. 3 is a coordinate system set in the position adjustment mechanism. 4 is an explanatory diagram of the inclination of the position adjustment mechanism, FIG. 5 is an explanatory diagram of the error in the trajectory of the scanning beam, and FIG. 6 is an explanatory diagram of other power distribution states of the pressing means constituting the position adjustment mechanism. It is an explanatory diagram. Ll... Recording laser beam L2... Synchronization laser beam 0... Main body 2.14... Laser diode 0... Light deflector 4... Main body 0... Deflection mirror 2. ...Spherical part 4...Holder 6...Press means...Position adjustment mechanism 0...Fixing base 2...Mounting base 4.46...Conical part 2a, 52b...Micrometer FIG, 3 b2゜

Claims (1)

[Claims] (1) A scanning device in which an optical deflector for scanning a light beam onto a scanned object is disposed, the optical deflector having a spherical part provided at one end side and a conical part in contact with the spherical part; A holder capable of rotating and fixing the spherical part; and a pressing means for pressing the other end of the optical deflector from biaxial directions intersecting each other to adjust the angular position of the optical deflector. A position adjustment mechanism for the scanning device.