JP3638766B2 - Multi-beam injection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light emitting device used in a writing system such as a digital copying machine and a laser printer, and more particularly to a multi-beam emitting device capable of switching a beam pitch by rotating a light source unit by a stepping motor.
[0002]
[Prior art]
As a means for increasing the recording speed in the light emitting device used in the writing system, there is a method for increasing the rotational speed of the rotary polygon mirror as the deflecting means. However, in this method, the durability of the motor, the material of the polygon mirror, and the like become problems, and the recording speed is limited. In order to reduce the rotational speed of the polygonal mirror without reducing the recording speed, it is only necessary to scan with a plurality of laser beams at a time.
[0003]
As such a multi-beam injection device, as disclosed in Japanese Patent Laid-Open No. 60-32019, a light source method for combining and emitting light beams from a plurality of semiconductor lasers, or Japanese Patent Laid-Open No. 2-54211 As disclosed in the official gazette, a light source method using a semiconductor laser array in which a plurality of light emitting sources are arranged in an array is proposed. The scanning line pitch is adjusted by adjusting the optical axis inclination in the sub-scanning direction in the former and the latter Is adjusted by the light source tilt around the optical axis. Further, the former has a feature that the range of use is wide because the wavelength and output can be selected in order to use the semiconductor laser. In order to solve the fluctuation of the beam pitch due to the fluctuation of the environment, there is an application by Japanese Patent Application No. 5-216800.
[0004]
In general, in a multi-beam injection apparatus, when a light source unit is attached to an apparatus frame, a predetermined scanning line pitch cannot be obtained due to an attachment error, a processing error of an optical element, and the like.
As a solution to such a problem, for example, there is one described in JP-A-9-43523.
[0005]
This device has a light source unit formed by substantially integrally combining two semiconductor lasers, a collimator lens that converts light beams from the semiconductor lasers into parallel light beams, and beam combining means that emits the light beams by overlapping them. In the multi-beam emitting apparatus that simultaneously and repeatedly scans a plurality of light beams, the light source unit is configured such that each light beam emitted from the beam combining unit is emitted at a predetermined angle in the main scanning direction, and The synthesized light beam is freely adjustable around the optical axis.
[0006]
Specifically, as shown in FIG. 13A, the light beam is adjusted so that the position of the second beam 2 emitted from another semiconductor laser is adjusted around the first beam 1 emitted from one semiconductor laser. Can be adjusted to rotate around the optical axis, whereby the writing density can be changed by changing the pitch between the first beam 1 and the second beam 2. In the example of FIG. 13 (a), when the second beam 2 is at the position A, the pitch P2 between the first beam 1 and the second beam 2 is reduced, so that the writing density is increased and the second beam 2 is B. When in position, the pitch P2 between the first beam 1 and the second beam 2 is wider than the pitch P1, so the writing density is low.
[0007]
As a means for rotating the light source unit so that the pitch of the first beam 1 and the second beam 2 is aimed at in this way, a stepping motor and an output shaft of the stepping motor and the light source unit are interposed. A sliding member formed with a threaded portion that is screwed to the output shaft so as to rotate the light source unit by converting the rotational drive of the stepping motor into a linear motion, and constantly bias the light source unit in one direction. Thus, there is a spring configured to bring the light source portion into contact with the output shaft of the stepping motor via the sliding member.
[0008]
By the way, in order to switch the light source unit to the rotation position A and the rotation position B with high accuracy in this way, as shown in FIG. 13B, the light source unit (reference numeral 3 in FIG. 13 indicates the center of the optical axis). ) Is moved from the rotation position A or the rotation position B to the home position (hereinafter referred to as H · P), and the stepping motor has the number of pulses corresponding to the amount of movement from this position to the rotation position B or the rotation position A. In general, it is considered that such a configuration is also adopted in the conventional apparatus.
[0009]
[Problems to be solved by the invention]
However, in such a conventional multi-beam injection device, the light source part is urged in one direction by a spring so that the light source part comes into contact with the output shaft of the stepping motor via the sliding member. Therefore, for example, when the spring urges the light source unit to the H / P side, the light source unit is positioned between the rotation position A and H / P from the rotation position A away from the H / P. Although the motor is driven by a predetermined pulse from the rotation position A to the rotation position B when rotating to the rotation position B (ie, A> B with respect to H · P), The amount of backlash generated in the thrust direction of the output shaft is as much as the output shaft of the motor moves in one direction due to the spring.
[0010]
For this reason, an angle error or a position error occurs when the light source unit is moved to the rotation position B, and there is a problem that the rotation position B cannot be positioned with high accuracy.
Therefore, the present invention provides a multi-beam emission device capable of preventing an angle error or a position error of the light source unit when the light source unit is rotated from a certain rotation position toward the urging direction of the urging member. The purpose is that.
[0011]
[Means for Solving the Problems]
  BookIn order to solve the above-described problems, the present invention substantially integrates a plurality of semiconductor lasers, a collimator lens that converts light beams from the semiconductor lasers into parallel light beams, and beam combining means for superimposing and emitting these light beams. The combined light source unit and each light beam emitted from the beam combining unit are rotated around the optical axis between one direction and the other direction so that each light beam is emitted at least at a predetermined angle in the main scanning direction. A multi-beam injection device having a rotation adjusting means for adjusting the movement, wherein the rotation adjusting means is attached to a stepping motor and an output shaft of the stepping motor, and converts the rotational drive of the stepping motor into a linear motion. The light source unit is rotated through the sliding member by constantly urging the light source unit in one direction. In the multi-beam injection apparatus comprising an urging member that abuts against the output shaft of the rotating motor, the stepping motor is provided with a motor frame, a rotor into which the output shaft is press-fitted, and the rotor interposed therebetween, and the rotor A pair of bearings rotatably attached to the motor frame;A spring washer configured to bias the output shaft of the stepping motor in the same direction as the biasing member biases the output shaft of the stepping motor.It is characterized by that.
[0012]
The operation of the first aspect of the invention will be described. First, a position where the light source portion is rotated in a predetermined direction with respect to a home position (hereinafter simply referred to as H · P) is defined as a first rotation position. When the position rotated to the position between 1 rotation position and H * P is made into the 2nd rotation position, urging | biasing member shall urge the light source part to the H * P side. At this time, the relationship between the first rotation position and the second rotation position is such that the rotation angle from H · P is such that the first rotation position> the second rotation position.
[0013]
Here, when the output shaft of the stepping motor moves to one direction side when the light source unit is rotated from the first rotation position to the second rotation position by the stepping motor, the backlash in the thrust direction of the output shaft Therefore, a deviation of the rotation angle or the position error with respect to the target position of the light source unit occurs.
For this reason, in the first aspect of the invention, the output shaft of the stepping motor does not move in the same direction as the direction in which the light source unit rotates to the H / P side (the same direction as the one direction side of the light source unit). By configuring, when the light source unit is moved from the first rotation position to the second rotation position, the backlash in the thrust direction of the output shaft of the stepping motor is prevented, and the rotation error or position of the light source unit is prevented. The shift can be prevented, and the light source unit can be positioned at the target position (second rotation position) with high accuracy.
[0017]
  BookThe described invention solves the above-mentioned problems.BeforeStepping motorBut,The light source unit is switched to a plurality of rotation positions between one direction and the other direction, and energization is interrupted each time the rotation position of the light source unit is switched.
  In this case, it is possible to prevent accumulation of rotation error or displacement error of the rotation position of the light source unit when the rotation position of the light source unit is changed repeatedly.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings.
FIGS. 1-8 is a figure which shows 1st Embodiment of the multi-beam injection apparatus which concerns on this invention. First, the configuration will be described. In FIG. 1, semiconductor lasers 11 and 12 are fixed to supports 13 and 14 respectively, and are joined to the back surface of a base 15 using screws 18 and 19 so that the optical axes of collimator lenses 16 and 17 described later coincide with each other. . The collimator lenses 16 and 17 are housed in a lens barrel, engaged with the fitting holes 15a and 15b of the base 15 in alignment with the semiconductor lasers 11 and 12, respectively, and bonded to convert each light beam into a parallel light beam. To do. Light emitted from the collimator lenses 16 and 17 is shaped by a diaphragm plate 20 formed so as to correspond to a perfect circular slit for each, and is synthesized by the beam synthesis means 21. In the present embodiment, the diaphragm plate 20 is provided separately, but the lens barrels of the collimator lenses 16 and 17 can also serve as this.
[0019]
Here, the beam combining means 21 will be described. The two semiconductor lasers 11 and 12 are arranged in the same plane with their pn junction surfaces aligned. One of the beams (the beam of the semiconductor laser 11 in the embodiment) has its polarization plane rotated by 90 ° by the half-wave plate 22 affixed to the incident surface of the beam synthesizing unit 21, and the beam synthesizing unit 21. Passes through the polarizing beam splitter surface 21b. The beam of the semiconductor laser 12 is internally reflected by the inclined surface 21a of the beam synthesizing means 21, reflected by the polarization beam splitter surface 21b of the beam synthesizing means 21, and synthesized with the beam near the optical axis of the reference semiconductor laser 12. Is done. The series of optical axes related to the semiconductor lasers 11 and 12 are set so as to be shifted from each other by an angle θ shown on the output side of the beam combining means 21 so as to correspond to positions slightly shifted in the main scanning direction. Has been.
[0020]
The beam combining means 21 and the diaphragm plate 20 are supported at predetermined positions on the back surface of the flange member 23 and are fixed to the base body 15 by screws 24 and 25. Each member of the optical path from the semiconductor lasers 11 and 12 to the flange member 23 is integrally fixed to a frame 26 in which a drive circuit for the semiconductor lasers 11 and 12 is formed, and forms the light source unit 10.
Further, a hollow cylindrical portion 23a protrudes from the flange member 23, and this cylindrical portion 23a is inserted into a hole 26a formed in the frame 26 of the main device, and at the outer peripheral portion of the cylindrical portion 23a. A spring 27 is attached.
[0021]
A protrusion 23b is formed at the tip of the cylindrical portion 23a, and the tip of the cylindrical portion 23a is inserted into the hole 26a and inserted into the hole 28a formed in the spring pressing member 28. The light source 10 is pulled in the direction of arrow α by attaching the projection 23b to the projection 28b formed on the pressing plate 28 by rotating the angle 28 by 90 °, and the cylindrical portion 23a is attached to the frame 26 as the center of the optical axis. Thus, the light source unit 10 is rotatably attached to the frame 26.
[0022]
Here, in order to establish this configuration, the diameter of the spring 27 must be larger than the diameter of the hole 26a, and the portion of the spring pressing plate 28 that receives the spring 27 must be wider than the diameter of the spring 27.
The flange member 23 and the frame 26 are made of plastic containing glass fiber, and stainless steel (not shown) having higher strength than plastic is interposed between the flange member 23 and the frame 26. For this reason, the sliding resistance between the flange member 23 and the frame 26 is reduced, and the wear resistance of the flange member 23 can be improved.
[0023]
Next, a control example of the multi-beam injection apparatus will be described. FIG. 2 shows a system of the multi-beam injection apparatus. In the figure, the light source section 10 is constituted by members of an optical path from the semiconductor lasers 11 and 12 to the flange member 23 in FIG. Each beam emitted from the light source unit 10 is incident on a polarization unit including a polygonal mirror 31 through a cylinder lens 30 and is repeatedly polarized in the main scanning direction by rotating the polygonal mirror 31. The beam reflected by the polygon mirror 31 is further projected as a spot on a predetermined scanning recording surface by a scanning lens including an fθ lens 32 and a toroidal lens 33. At this time, two scanning lines are simultaneously written by assuming that each beam is shifted by 1 pitch p in the sub-scanning direction.
[0024]
  A photosensor 34 as a light amount detecting means is disposed in the vicinity of the surface to be scanned and detects a scanning beam in a non-writing area. Calculation unit 35aReceives the detected data and compares it with a predetermined reference value to calculate a deviation amount from the initial value. Semiconductor laser controller 36aControls the beam output of the semiconductor laser drive circuit to reduce the deviation. The photo sensor 34 and the semiconductor laser control unit 36 constitute a light amount variable control means.
[0025]
The rotation drive unit 37 includes a stepping motor and a sliding member, which will be described later, and rotates the light source unit 10. The rotation drive unit 37 is configured such that the HP position is always detected by a home position (hereinafter referred to as HP / P) sensor 29 serving as a detection member. Based on the command signal from the control unit 38, rotation adjustment control to be described later is performed.
[0026]
Next, the configuration of the rotation drive unit 37 will be described.
In FIG. 1, a rod-shaped member 23c is provided on one side surface of the flange member 23, and a sliding member 39 can come into contact with an end portion of the rod-shaped member 23c. The sliding member 39 has a D-shaped outer shape as shown in FIG. 3A, and an M3 screw portion 39a is formed on the inner peripheral portion as shown in FIG. It is inserted through the formed hollow cylindrical part 26b. Note that the inner peripheral portion of the cylindrical portion 26b is also D-shaped like the outer shape of the sliding member 39.
[0027]
A feed screw 40a formed on a nominal diameter M3 formed on the output shaft of the stepping motor 40 is formed on the inner peripheral portion of the sliding member 39 (separately shown in FIG. The output shaft is integral). Therefore, when the stepping motor 40 is driven to rotate, the sliding member 39 slides in one direction approaching the motor 40 side in the cylindrical portion 26b and in the other direction away from the motor 40, that is, in the vertical direction in FIG. To do.
[0028]
Further, a spring (biasing member) 41 is interposed between the frame 26 and the rod-like member 23c. The spring 41 presses the rod-like member 23c against the upper surface of the sliding member 39, so that the flange member 23 is integrated. The flange member 23 is brought into contact with the output shaft of the motor 40 via the sliding member 39 by always energizing the direction side (motor 40 side). Therefore, when the stepping motor 40 is driven to rotate, the light source 10 rotates about the cylindrical portion 23a constituting the optical axis as the sliding member 39 moves in the vertical direction within the cylindrical portion 26b. .
[0029]
Further, a detection filler 23 d is formed on the other side surface of the flange member 23, and this detection filler 23 d is detected by the H / P sensor 29. Specifically, as shown in FIG. 1, in the H / P sensor 29, a light emitting element 29a and a light receiving element 29b are arranged to face each other, and the tip of the detection filler 23d is located between the light emitting element 29a and the light receiving element 29b. The H / P position is detected at the moment when the light receiving element 29b is inserted and shielded. In other words, the H / P sensor 29 is arranged at the H / P position, and detects the H / P position which is the reference for the rotation of the light source unit 10 when the detection filler 23d is detected.
[0030]
Next, the rotation position of the light source unit 10 will be described.
FIG. 4A is a diagram showing the rotation position of the light source unit 10, and the installation positions of the light emitting element 29a and the light receiving element 29b are the HP and P positions. From this HP position, the position where the light source unit 10 is rotated by θ1 in a predetermined direction around the optical axis as the rotation center is the rotation position A (first rotation position), and the light source unit 10 is in the predetermined direction around the optical axis as the rotation center. The position rotated by θ2 is the rotation position B (second rotation position), and this rotation position B is located between the rotation positions A and HP. That is, the relationship between the rotational position A and the rotational position B is θ1> θ2 with H · P as a reference.
[0031]
In order to rotate the light source unit 10 from H / P to the rotation position B, the stepping motor 40 is moved by a predetermined pulse in a predetermined direction, the sliding member 39 is moved upward, and the light source unit 10 is moved to H. In order to rotate from P to the rotation position A, the stepping motor 40 is moved in a predetermined direction by a pulse equal to or more than the pulse, and the sliding member 39 is further moved upward.
[0032]
Further, as shown in FIG. 4B, the pitches of the beams 10a and 11a are P1 and P2 corresponding to the rotation angles θ1 and θ2, respectively, and the relationship of P2> P1 is established. Here, for example, the rotation position A corresponds to a writing density of 600 dpi, and the rotation position B corresponds to a writing density of 400 dpi. As a matter of course, the higher the writing density, the two beams The pitch of 10a and 11a becomes narrow.
[0033]
Further, the control unit 38 rotates to the rotation position B after rotating the light source unit 10 to HP by the stepping motor 40 only when moving the light source unit 10 from the rotation position A to the rotation position B. When the light source unit 10 is rotated from the rotation position B to the rotation position A, the light source unit 10 is rotated to the rotation position A without being rotated by the stepping motor 40 to HP. It comes to control. In the present embodiment, the rotation drive unit 37, the H / P sensor 29, and the control unit 38 including the sliding member 39 and the stepping motor 40 constitute a rotation adjusting unit.
[0034]
  The control unit 38 cuts off the energization of the motor 40 every time the motor 40 is driven to switch the flange member 23 between the rotation position A and the rotation position B.
  Next, the configuration of the stepping motor 40 will be described with reference to FIG. As shown in FIG.,Rotor 43 press-fitted into motor shaft (output shaft) 42But this rotor 43 A pair ofMotor frame 45 by bearing 44Freely rotatableInstalled.
[0035]
  A starter 46 is attached to the inside of the motor frame 45, and one of the rotor 43 and the stator 46 is composed of a permanent magnet or an electromagnet. Further, in order to restrict the movement of the motor shaft 42 in the thrust direction, a spring washer 47 is provided as shown in FIG.Upper bearing 44 And rotor 43 This spring washer is interposed between 47Therefore, when a force is applied in the direction indicated by the arrow β of the motor shaft 42 (the direction in which the flange member 23 is moved to the rotational position A side), rattling occurs.
[0036]
  For this reason, the motor shaft 42 does not move in the direction opposite to the β direction (the direction opposite to the direction in which the flange member 23 is moved to the rotation position A), and no play occurs in this direction.Ie, spring washer 47 The spring 41 Stepper motor 40 Motor shaft 42 Stepping motor in the same direction as energizing 40 Motor shaft 42 Configured to energize.
  Next, a method of switching the rotation position (beam pitch) of the light source unit 10 will be described based on the flowcharts shown in FIGS.
[0037]
First, pitch switching control for rotating the light source unit 10 from the rotation position A to the rotation position B will be described. In the present embodiment, when the stepping motor 40 in FIG. 1 is viewed from the front motor shaft direction, the clockwise direction is defined as the CCW direction, and the counterclockwise direction is defined as the CW direction.
As shown in the flowchart of FIG. 6, when the light source unit 40 is in the rotation position A, when a pitch switching execution command is generated from the control unit 38, the motor 40 is rotationally driven in the CCW direction (step S1). At this time, since the sliding member 39 moves downward, the flange member 23 rotates clockwise and the detection filler 23d moves upward.
[0038]
Next, it is determined whether or not the detection filler 23d has shielded the light receiving element 29b (step S2), and when it is determined that it has been shielded, the light source unit 10 is located at H and P and is at the reference position, so the motor 40 Is stopped (step S3).
Next, the motor 40 is rotated in the CW direction by a predetermined number of pulses corresponding to the rotation position B from H · P (step S4). At this time, since the sliding member 39 moves upward, the flange member 23 rotates counterclockwise. When the motor 40 is rotationally driven by a predetermined pulse, when the motor 40 is stopped and the power supply to the motor 40 is interrupted, the light source unit 10 is rotated to the rotation position B and positioned. The operation of moving the light source unit 10 to the rotation position A or the rotation position B after moving the light source unit 10 to HP is hereinafter referred to as a homing operation.
[0039]
On the other hand, when a pitch switching execution command is generated from the control unit 38 when the light source unit 40 is at the rotation position B, a predetermined pulse corresponding to the rotation position A from the rotation position B is generated, as shown in the flowchart of FIG. The motor 40 is rotationally driven in the CW direction by the number (step S11). At this time, since the sliding member 39 moves upward, the flange member 23 rotates counterclockwise. When the motor 40 is rotationally driven by a predetermined pulse, when the motor 40 is stopped and the motor 40 is de-energized, the light source unit 10 is rotated to the rotation position A and positioned. It should be noted that since the operation to cut off the power to the motor 40 is surely performed every time the rotation position A and the rotation position B are positioned, the description thereof will be omitted.
[0040]
Next, the reason why the above-described control is performed will be described.
When the motor shaft 42 is moved downward in FIG. 1 by the biasing force of the spring 41 when the light source unit 10 is rotated from the rotation position A to the rotation position B by the motor 40, the thrust of the motor shaft 42 is thrust. Due to the backlash in the direction, a deviation of the rotation angle or the position error with respect to the target position of the light source unit 10 occurs.
[0041]
For this reason, in this embodiment, the motor 40 is configured so that the motor shaft 42 does not move in the same direction as the direction in which the light source unit 10 rotates to the H / P side. It is possible to prevent backlash of the screw shaft 39a and backlash in the thrust direction of the motor shaft 42 when the light source unit is moved, and to prevent rotation error or displacement of the light source unit 10. 10 can be positioned at the target position with high accuracy.
[0042]
Further, when the light source unit 10 is rotated from the rotation position B to the rotation position A, the light source unit 10 is directly rotated from H / P to the rotation position A. There is no backlash in the thrust direction generated from above and the backlash of the screw portion 39a of the sliding member 39.
Therefore, when the light source unit 10 is rotated from the rotation position B to the rotation position A, the motor 40 rotates the light source unit 10 to the rotation position A without rotating the light source unit 10 to HP. The switching time can be shortened by not performing the homing operation. Further, a member having low durability and wear resistance of the motor 40 and the sliding member 39 can be used as much as the homing operation is reduced.
[0043]
In the present embodiment, since the power supply to the motor 40 is cut off every time the light source unit 10 is switched between the rotation position A and the rotation position B, the rotation position of the light source unit 10 is repeatedly changed. In this case, it is possible to prevent the rotation error or the displacement error of the rotation position of the light source unit 10 from being accumulated.
This point is clear from the experimental results shown in FIG. That is, when the power supply to the motor 40 is not interrupted every time the light source unit 10 is switched between the rotation position A and the rotation position B, the light source unit 10 In the case of turning off the power to the motor 40 every time the light source unit 10 is switched to the rotation position A and the rotation position B, while the rotation error or the displacement error of the rotation position is accumulated to the right. As shown by the dots, every time the rotation position is switched, a rotation error or displacement error of the rotation position of the light source unit 10 does not occur, and a certain amount between the rotation position A and the rotation position B. You can see that it is moving.
[0044]
9 and 10 are views showing a second embodiment of the multi-beam injection apparatus according to the present invention. The present embodiment is characterized in that the homing operation is not performed when the light source unit 10 is rotated between the rotation position A and the rotation position B, and the control method is different from that of the first embodiment. Is the same as that of the first embodiment, and will be described with reference to the drawings of the first embodiment. Further, since the structure of the motor 40 is the same as that of the motor shown in the first embodiment, description thereof is omitted.
[0045]
FIG. 9 is a diagram showing a method of switching the rotation position (beam pitch) of the light source unit 10, and FIG. 10 shows the backlash and sliding in the thrust direction of the motor shaft 42 generated from the structure of the motor 40 obtained by experiments. FIG. 5 is a diagram illustrating how to obtain a pulse for taking a pulse fluctuation due to backlash of a screw portion 39a of a moving member 39;
In the present embodiment, when the light source unit 10 is moved from the rotation position A to the rotation position B, the control unit 38 drives the motor 40 by a pulse amount that moves the rotation position A to the rotation position B. After the light source unit 10 is moved to the rotation position B, the motor 40 is driven in the same direction as the rotation direction by a preset pulse, and the motor 40 is moved in the rotation direction by a set pulse. By driving in the reverse direction, the light source unit 10 is positioned at the rotation position B, and when the light source unit 10 is rotated from the rotation position B to the rotation position A, the motor 40 moves the light source unit 10 to H · P. The control unit 38, the stepping motor 40, and the sliding member 39 constitute a rotation adjusting means.
[0046]
Next, the operation will be described.
When a pitch switching execution command is generated from the control unit 38 when the light source unit 10 is in the rotation position A, a calculation of CD is performed (step S21). Here, C is the number of pulses of the motor 40 for moving from H · P to the rotation position A, and D is the number of pulses of the motor 40 for moving from H · P to the rotation position B.
[0047]
As a result, the positional difference E by the rotation pulse of the motor 40 between the rotation position A and the rotation position B is obtained.
Next, when the motor 40 is rotationally driven in the CCW direction by an amount corresponding to the pulse E, the sliding member 39 moves downward, so that the flange member 23 rotates clockwise and stops (steps S22 and S23). At this time, theoretically, this position becomes the rotation position B as much as the backlash of the screw portion 39a does not exist.
[0048]
However, as described in the first embodiment, there is a pulse fluctuation due to backlash in the thrust direction of the motor shaft 42 generated from the structure of the motor 40 and the backlash of the screw portion 39a of the sliding member 39. Unlike the general position, the light source unit 10 is not located at the rotation position B.
For this reason, the motor 40 is driven to rotate in the CCW direction by F pulses, thereby obtaining an adjustment margin for rotation in the CW direction for adjustment in the next step (step S24). That is, the pulse F causes the motor 40 to rotate in the CCW direction extra in order to take the fluctuation of the pulse caused by the backlash of the screw portion 39a of the sliding member 39 and the backlash of the motor shaft 42 generated from the structure of the motor 40. For the number of pulses.
[0049]
Next, the motor 40 is set to CW by the pulse J for adjusting the fluctuation in the thrust direction of the motor shaft 42 generated from the structure of the motor 40 obtained by the experiment and the pulse fluctuation due to the backlash of the screw portion 39a of the sliding member 39. The direction is rotated (step S25). As a result, the light source unit 10 is positioned at the rotation position B.
Next, how to obtain the pulse C will be described with reference to FIG.
[0050]
First, the motor 40 is rotated from an arbitrary position G to, for example, 100 pulses CCW, and the detection filler 23d is rotated to the H position. Next, when the motor 40 is rotated in the direction of 100 pulses CW from this position H, the detection filler 23d stops at the position indicated by I due to the backlash and the backlash of the motor described above. This difference, that is, GH-IH is a value of J, which is a value for taking a pulse fluctuation.
[0051]
Further, since the method of rotating the light source unit 10 from the rotation position B to the rotation position A is the same as that of the first embodiment, the description thereof is omitted.
As described above, in the present embodiment, the motor 40 is configured so that the motor shaft 42 does not move in the same direction as the direction in which the light source unit 10 rotates to the H / P side. It is possible to prevent backlash of the screw shaft 39a and backlash in the thrust direction of the motor shaft 42 when the light source unit is moved, and to prevent rotation error or displacement of the light source unit 10. 10 can be positioned at the target position with high accuracy.
[0052]
When moving the light source unit 10 from the rotation position A to the rotation position B, the motor 40 is driven in the CCW direction by the pulse E for moving the motor 40 from the rotation position A to the rotation position B. After moving to the moving position B, the motor 40 is driven in the CCW direction by the pulse F, and the motor 40 is further driven in the CW direction by the pulse J determined by the experiment, whereby the light source unit 10 is rotated. When the light source unit 10 is moved from the rotation position A to the rotation position B because it is positioned at B, the backlash in the thrust direction generated from the structure of the motor 40 and the backlash of the screw portion 39a of the sliding member 39 are caused. The error or the positional deviation can be corrected, and the light source unit 10 can be positioned at the rotational position B with higher accuracy.
[0053]
Further, when the light source unit 10 is rotated from the rotation position B to the rotation position A, the light source unit 10 is rotated as it is without rotating the light source unit 10 to HP by the motor 40. It is possible to position at the rotational position A with higher accuracy.
Further, since the homing operation is not performed when the light source unit 10 is rotated between the rotation position A and the rotation position B, the switching time can be further shortened. Further, as long as the homing operation is not performed, a member having low durability and wear resistance of the motor 40 and the sliding member 39 can be used.
[0054]
FIG. 11 is a view showing a third embodiment of the multi-beam injection apparatus according to the present invention. Although the present embodiment shows an example in which a multi-beam injection device is mounted on a printer, the basic configuration and the structure of the motor 40 are the same as those in the first embodiment, so the configuration of the multi-beam injection device Is described with reference to the drawings of the first embodiment.
In FIG. 11, reference numeral 50 denotes a first board, and this first boat has a CPU, and controls the entire printer apparatus such as an engine sequence, timing control of each member, image processing, control of an operation unit, Responsible for system control. A PSU (Power Supply Unit) 51 and a semiconductor laser unit 52 for supplying power are connected to the first boat 50.
[0055]
Reference numeral 53 denotes a second board. The second boat 52 includes various sensors 55 and actuators 56 of the paper feed / control unit 54, a main motor 57 of the printer device, various sensors 58, actuators 59, a power pack 60, and the above. The stepping motor 40 and the H / P sensor 29 are controlled. In short, the board has input / output ports and drivers for controlling the load of sensors, actuators and the like of the plotter unit, a PWM control unit for controlling high-voltage power supply, and a fixing control circuit. The PSU 51 supplies power to the fixing heater 61.
[0056]
In the present embodiment, a configuration corresponding to the CPU control unit 38 is incorporated in the first board 50, and after the power source of the printer device is turned on, the motor 40 moves the light source unit 10 to HP. It moves to the rotation position A or the rotation position B, It is characterized by the above-mentioned.
Hereinafter, the operation will be specifically described.
[0057]
In this embodiment, when a power source provided in the operation unit is turned on and a voltage is supplied to the PSU 51, a reset signal is sent to the CPU of the first boat 50, and the motor is driven by the first boat 53 based on the reset signal. 40 is operated, and the light source unit 10 is moved to the rotation position A or the rotation position B through H and P.
In this way, in addition to the same effects as in the first embodiment, the pitch of the light source unit 10 due to vibration or impact of the printer device is not performed for a period of time during which the pitch position (rotation position) of the light source unit 10 is switched. Turn on the power when the position changes over time, or when the switching operation is performed several times without performing the homing operation as in the second embodiment, the error accumulates and the pitch fluctuates. Sometimes, performing the homing operation prevents the accumulation of pitch fluctuations and accumulated pitch errors over time, and the light source unit 10 can be rotated and adjusted with high accuracy. .
[0058]
FIG. 12 is a view showing a fourth embodiment of the multi-beam injection apparatus according to the present invention. In this embodiment, the control method is different from that of the first embodiment, and the overall configuration and the structure of the motor are the same as those of the first embodiment. Therefore, the control method will be described with reference to the drawings of the first embodiment.
In this embodiment, the control unit 38 performs switching from the rotation position A to the rotation position B of the light source unit 10 or switching from the rotation position B to the rotation position A of the light source unit 10 a predetermined number of times or more. The light source unit 10 is moved to HP by the motor 40 and then moved to the rotational position A or the rotational position B.
[0059]
Next, the operation will be described based on the flowchart shown in FIG.
When a pitch switching execution command is generated from the control unit 38, the execution command is counted (step S31). Next, it is determined whether or not the pitch switching count has reached N times (step S32), and if not, switching control that does not execute the homing operation is continued.
[0060]
If N times have been reached, the motor 40 is driven to rotate in the CCW direction (step S33). At this time, since the sliding member 39 moves downward, the flange member 23 rotates clockwise. Thus, the detection filler 23d moves upward. Next, it is determined whether or not the detection filler 23d has shielded the light receiving element 29b (step S34), and when it is determined that it is shielded, it is determined that the light source unit 10 has reached H · P and the motor 40 is driven. Is stopped (step S35).
[0061]
Next, the motor 40 is rotationally driven in the CW direction by a predetermined number of pulses from H and P (step S36), the light source unit 10 is positioned at the rotational position A or the rotational position B, and this control is finished.
In this way, the same effect as that of the first embodiment can be obtained, and the motor 40 is not used when the rotational position of the light source unit 10 is switched more than a predetermined number of times, not when the power is turned on. By moving the light source unit 10 to H and P, it is possible to prevent the accumulation of pitch fluctuations and accumulated pitch errors over time, and to rotate and adjust the light source unit 10 with high accuracy.
[0064]
【The invention's effect】
  BookAccording to the invention, when the light source unit is moved from the first rotation position to the second rotation position, it is possible to prevent occurrence of backlash in the thrust direction of the output shaft of the stepping motor. The shift can be prevented, and the light source unit can be positioned at the target position with high accuracy.
[0065]
  BookAccording to the invention, it is possible to prevent accumulation of rotational errors or misalignment errors of the rotational position of the light source unit when the rotational position of the light source unit is repeatedly changed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of a multi-beam injection apparatus according to the present invention, and is a perspective exploded view of an optical part thereof.
FIG. 2 is a schematic configuration diagram of a multi-beam injection apparatus according to the first embodiment and an apparatus for processing a beam emitted from the injection apparatus.
3A is a top view of the sliding member of the first embodiment, and FIG. 3B is a cross-sectional view of the sliding member.
4A is a diagram showing a rotational position of the light source unit according to the first embodiment, and FIG. 4B is a diagram showing a relationship between the rotational position of the light source unit and the beam pitch.
FIG. 5A is a structural view showing a part of the stepping motor according to the first embodiment in section, and FIG. 5B is an external view of a spring washer.
FIG. 6 is a flowchart of pitch switching control for rotating the light source unit from the rotation position A to the rotation position B according to the first embodiment.
FIG. 7 is a flowchart of pitch switching control for rotating the light source unit from the rotation position B to the rotation position A according to the first embodiment.
FIG. 8 shows the displacement of the light source unit when the motor is deenergized when the light source unit of the first embodiment is moved between the rotation position A and the rotation position B and when the motor is energized. It is a figure which compares.
FIG. 9 is a diagram showing a second embodiment of the multi-beam injection apparatus according to the present invention, and is a flowchart showing a method for switching the rotation position (beam pitch) of the light source unit.
FIG. 10 is a diagram illustrating how to obtain a pulse for taking a pulse fluctuation due to backlash in a thrust direction and backlash generated from the structure of the stepping motor obtained by the experiment of the second embodiment.
FIG. 11 is a diagram showing a third embodiment of a multi-beam injection apparatus according to the present invention, and is a configuration diagram of a printer apparatus.
FIG. 12 is a view showing a fourth embodiment of the multi-beam injection apparatus according to the present invention, and is a flowchart of a homing operation.
FIG. 13A is a diagram showing the rotational position of the light source unit, and FIG. 13B is a diagram showing the relationship between the rotational position of the light source unit and the beam pitch.
[Explanation of symbols]
10 Light source
11, 12 Semiconductor laser
16, 17 Collimator lens
21 Beam synthesis means
39 Sliding member (rotation adjustment means)
40 Stepping motor (rotation adjustment means)
41 Spring (biasing member)

Claims (2)

A light source unit obtained by substantially integrally combining a plurality of semiconductor lasers, a collimator lens that converts light beams from the semiconductor lasers into parallel light beams, and beam combining means for superimposing and emitting these light beams;
A rotation adjusting means for rotating and adjusting the light source unit between one direction and the other direction around the optical axis so that each light beam emitted from the beam combining unit is emitted at least at a predetermined angle in the main scanning direction; A multi-beam injection device comprising:
The rotation adjusting means is attached to a stepping motor, an output shaft of the stepping motor, a sliding member for rotating the light source unit by converting the rotational drive of the stepping motor into a linear motion, and the light source unit. In the multi-beam injection device constituted by a biasing member that abuts the light source part on the output shaft of the stepping motor via the sliding member by always biasing in one direction side,
The stepping motor includes a motor frame, a rotor in which an output shaft is press-fitted, a pair of bearings that are provided to sandwich the rotor, and rotatably attach the rotor to the motor frame, and a spring washer.
The multi-beam injection apparatus according to claim 1, wherein the spring washer is configured to bias the output shaft of the stepping motor in the same direction as the biasing member biases the output shaft of the stepping motor . The stepping motor, with switching to a plurality of rotational positions between the light source portion in one direction and the other direction, according to claim 1 Symbol energization whenever switching the rotational position of the light source unit is characterized in that it is cut off multibeam injection equipment mounting.

Images