JP2008217196A - Positioning device and positioning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning device and a positioning method, positioning a moving member so that the detection output becomes maximum in a short time. <P>SOLUTION: According a positioning method for moving the moving member moved within a movable range by a driving device so that the detection output of the position detecting means whose detection output changes depending on the position of the moving member becomes maximum, the moving member is returned to the origin at the end of the movable range, the detection output is confirmed every time the moving member is pitch-fed by a predetermined moving amount each, and when the detection output is more than a predetermined threshold, scanning is performed to stop pitch-feeding, the moving member is moved from the stopped position by a predetermined vary small amount by scanning to confirm the detection output, and perform fine adjustment for moving the moving member in the direction estimated to increase the detection output. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a positioning device and a positioning method.

  For example, Patent Document 1 describes a laser device that guides a laser beam emitted from a light projecting unit such as a laser oscillator to an optical receiving member such as an optical fiber by an optical member such as a lens.

  In Patent Document 1, the optical member is microvibrated with a constant period and a constant amplitude, the change in the intensity of the laser light in the optical fiber is measured, and the moving direction and movement of the optical member for maximizing the received light intensity of the laser light. The laser beam is positioned with respect to the optical fiber by a method called wobbling for calculating the quantity. However, when the laser beam is misaligned, it is necessary to repeat this wobbling, and there is a problem that it takes a considerable time to accurately position the optical member.

  In such a laser device, the optical member is moved by a predetermined amount, whether or not the received light intensity is increased, and is continuously increased by a predetermined amount in the direction in which the received light intensity increases until the received light intensity starts to decrease. A control method called hill climbing control is also known. This hill-climbing control is capable of aligning with higher accuracy than wobbling, but has a problem that the time required for positioning is longer than that of wobbling.

In particular, when the movable range of the optical member is wide, the received light intensity becomes zero when the laser beam is greatly deviated from the light receiving member, and the maximum point of the received light intensity may not be found by wobbling.
JP 2003-338895 A JP-A-6-265759

  In view of the above problems, the moving member can be positioned so that the detection output is maximized in a short time, and the detection output is maximized even if the position is shifted so that the detection output cannot be obtained. It is an object of the present invention to provide a positioning device and a positioning method capable of positioning a device.

  In order to solve the above-mentioned problem, a positioning device according to the present invention includes a moving member that is moved within a movable range by a driving device, and a position detecting unit that has a maximum detection output when the moving member is at a predetermined position, The moving member is returned to the end of the movable range and the detection output is checked every time the moving member is pitch-fed by a predetermined movement amount. If the detection output is equal to or greater than a predetermined threshold, the pitch feed is The moving member is moved from the position stopped by the scanning by a predetermined minute amount, the detection output is confirmed, and the moving member is moved in a direction in which the detection output is expected to increase. Control means for performing fine adjustment to be moved.

  According to this configuration, the moving member is quickly moved by pitch feed to the vicinity of the peak position of the detection output by scanning, and is positioned at an accurate peak position from near the peak position by fine adjustment such as wobbling or mountain climbing control. . As a result, the positioning member can be accurately positioned in a short time at a position where the detection output is maximized.

  Further, in the positioning device of the present invention, in the scan, if the movement amount of the pitch feed of the moving member is less than or equal to ½ of the width of the position of the moving member at which the detection output is equal to or greater than the threshold value, It can be prevented that the pitch of the detected main force jumps over the peak of the detection main force and the stop position of the moving member cannot be found by one pitch feed.

  In the positioning device of the present invention, the number of movements of the moving member pitch-fed by the scan is stored, and when performing the scan later, the moving member returned to the origin is less than the stored number of movements. If confirmation of the detection output is started from the position where the pitch is fed by the skip count, the time required for the second and subsequent scans can be shortened.

  In the positioning device of the present invention, if the storage of the number of movements is updated every time the scan is performed, even if the driving amount of the driving device changes due to a change over time, the detection output can be appropriately and quickly performed. The maximum position can be found.

  In the positioning device of the present invention, if the number of skips is set to a number obtained by subtracting a predetermined number of margins from the number of movements, the detection output can be output even if the drive amount of the drive device changes suddenly due to environmental changes or the like. The maximum position can be found without skipping by skipping.

  In the positioning device of the present invention, the return to origin can correct a positional shift due to gravity by moving the moving member to the upper moving end.

  Further, according to the present invention, the moving member that is moved within the movable range by the driving device moves the moving member so that the detection output of the position detecting means whose detection output changes according to the position of the moving member is maximized. The positioning method for positioning the member is to return the origin of the moving member to the end of the movable range, check the detection output every time the moving member is pitch-fed by a predetermined movement amount, and the detection output is a predetermined value. If it is equal to or greater than a threshold value, a scan for stopping the pitch feed is executed, the moving member is moved by a predetermined minute amount from the position stopped by the scan, the detection output is confirmed, and the moving member is detected by the detection output. A fine adjustment is made to move in a direction where the increase is expected to increase.

  According to the present invention, by scanning, the moving member is pitch-fed to the vicinity of the peak position of the detection output to quickly move, and from the vicinity of the peak position to the accurate peak position by fine adjustment such as wobbling or hill climbing control. Since the member is positioned, accurate positioning can be performed in a short time.

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 shows a positioning device 1 according to a first embodiment of the present invention. The positioning device 1 includes a laser diode 2 that generates laser light, a fixed light projecting lens 3, and a moving lens (moving member) 5 that can be moved by the driving device 4 in two directions XY orthogonal to the laser light. A second harmonic generation element (Second Harmonic Generation) 6 in which the laser light is incident through the light projecting lens 3 and the moving lens 5, an emission lens 7 for emitting the output of the second harmonic generation element 6, and a first A half mirror 8 that splits the output of the second harmonic generation element 6, a power monitor (position detection means) 9 that converts the output level of the split second harmonic generation element 6 into a voltage signal (detection output), and a power monitor And a control device (control means) 10 for moving the moving lens 5 in the Y-Y direction according to the detection output 9.

  The second harmonic generation element 6 has a light receiving portion with a diameter of about 1 to 3 μm. The moving lens 5 condenses the laser light so as to have the same diameter as the light receiving portion of the second harmonic generation element 6, and the optical axis of the laser light at the center of the light receiving portion of the second harmonic generation element 6. Align the center.

  When the optical axis of the laser beam coincides with the center of the second harmonic generation element 6 by the moving lens 5, all the energy of the laser beam is input to the second harmonic generation element 6. The output of the element 6 is maximized, and the detection output of the power monitor 9 is also maximized.

  FIG. 2 shows a configuration of the driving device 4 that moves the moving lens 5. The drive device 4 includes an X-axis actuator 12 fixed to the housing 11 and a Y-axis actuator 13 that is moved in the X-axis direction by the X-axis actuator 12 and moves the moving lens 5 in the Y-axis direction. .

  One end of the X-axis actuator 12 is fixed to the housing 11, and when a voltage is applied, the X-axis piezoelectric element 14 expands and contracts in the X-axis direction, and the X-axis piezoelectric element 14 expands and contracts to reciprocate in the X-axis direction. The shaft drive shaft 15 includes an X-axis friction engagement member 16 that frictionally engages the X-axis drive shaft 15, and an X-axis stopper 17 provided at the tip of the X-axis drive shaft 15. One end of the Y-axis actuator 13 is fixed to the X-axis friction engagement member 16, and when a voltage is applied, the Y-axis piezoelectric element 18 expands and contracts in the Y-axis direction, and the Y-axis piezoelectric element 18 expands and contracts in the Y-axis direction. A Y-axis drive shaft 19 that reciprocates, a Y-axis friction engagement member 20 that frictionally engages the Y-axis drive shaft 19, and a Y-axis stopper 21 provided at the tip of the Y-axis drive shaft 19, The friction engagement member 20 holds the moving lens 5. The X-axis friction engagement member 16 can move between the X-axis piezoelectric element 14 and the X-axis stopper 17 as a movable range, and the Y-axis friction engagement member 20 includes a Y-axis piezoelectric element 18 and a Y-axis stopper 21. Can be moved as a movable range.

  As shown in FIG. 3, the position of the moving lens 5 can be represented on the XY coordinates, and is positioned at the alignment position shown in the figure by the driving device 4, so that the output of the second harmonic generation element 6 is obtained. And the detection output of the power monitor 9 can be maximized (for example, 3V). However, the exact alignment position in each positioning device 1 is unknown due to manufacturing variations and the like.

  FIG. 4 shows a flow of control of the driving device 4 by the control device 10 of the present embodiment. If the positioning device 1 is activated, the control device 10 first returns the moving lens 5 to the origin in step S1 (see FIG. 5). To return to the origin, the X-axis actuator 12 and the Y-axis actuator 13 are operated in reverse directions much more than the X-axis friction engagement member 16 and the Y-axis friction engagement member 20 move from end to end of their respective movable ranges. Is applied by mechanically butting the X-axis friction engagement member 16 and the Y-axis friction engagement member 20 against the moving end of the movable range.

  Temporarily, in the X-axis actuator 12, the number of design drive pulses required to bring the X-axis friction engagement member 16 in contact with the X-axis stopper 17 into contact with the X-axis piezoelectric element 14 is 1000 times. Then, in step S1, the X-axis actuator 12 is input to the X-axis actuator 12 to return to the origin, but the number of pulses is set to be larger than the designed number of pulses, for example, 1200 times, so that the X-axis actuator 12 can be reliably Can be restored.

  The origin of the Y-axis actuator 13 is set at a position where the Y-axis friction engagement member 20 contacts the upper Y-axis stopper 21. This is because, when the Y-axis friction engagement member 20 is moved when not in use, it is often dropped downward due to gravity. Therefore, when returning to the origin, the Y-axis friction engagement member 20 is moved upward. This is because an effect such as the elimination of sticking of the member 20 can be expected.

  Subsequently, in step S2, the control device 10 drives the X-axis actuator 12 to move the moving lens 5 in the X-axis direction by the stored skip amount, but the initial value of the skip amount is zero. First, it is assumed that there is no processing in step S2.

  In step S <b> 3, the control device 10 confirms the detection output of the power monitor 9. If the detection output is less than a predetermined threshold value (for example, 1V), the process proceeds to step S4, and as shown in FIG. 5, scanning is performed to scan and move the moving lens 5 at a predetermined pitch in the XY direction. In the present embodiment, the Y axis is the main scanning direction, and the X axis is the sub scanning direction. That is, the moving lens 5 moves by a predetermined pitch in the Y-axis direction from the origin, and when it reaches the opposite side of the movable range, it is fed by one pitch in the X-axis direction, and this time, one pitch in the Y-axis direction. Reverse feed. When the moving end is reached again in the Y-axis direction, it is further moved by one pitch in the X-axis direction, and the direction is changed again in the Y-axis direction to feed the pitch. The control device 10 confirms the value of the detection output in step S3 every time the moving lens 5 is moved by one pitch in the X-axis direction or the Y-axis direction by the driving device 4.

  If the detection output is equal to or greater than the threshold value in step S3, the scan is terminated, the process proceeds to step S5, and the number of times the moving lens 5 is pitched in the X-axis direction (seven times in FIG. 5) is Store in memory.

  As shown in FIG. 3, when the moving lens 5 reaches a certain distance from the alignment position, the detection output becomes equal to or greater than the threshold value. However, when the laser beam is distorted, the scanning stop range is distorted elliptically.

  Here, the pitch feeds in the X-axis direction and the Y-axis direction are the width of the position of the moving lens 5 where the detection output is equal to or greater than the threshold, the diameter in the X-axis direction and the Y-axis direction of the scan stop range in FIG. By setting it to 1/2 (e.g., 20 pulses) or less of the equivalent of the pulse, it is possible to prevent the movable lens 5 from jumping over the scan stop range by one pitch feed and making it impossible to find the alignment position.

  Subsequently, in step S6 of FIG. 3, the control device 10 repeats the wobbling of the X axis and the Y axis in order, and continuously performs the operation of bringing the moving lens 5 closer to the alignment position.

  FIG. 6 shows an outline of wobbling. The wobbling is performed one by one for the X-axis and the Y-axis in order. Here, the X-axis will be described. First, it is assumed that the moving lens 5 is positioned at P0, and the detection output at this time is V0. First, a pulse (for example, two pulses) for sequentially feeding the X-axis friction engagement member 16 by a predetermined minute amount is input to the X-axis actuator 12. After the movement, the position of the moving lens 5 is P1, and the detection output is V1. Further, a pulse (for example, 4 pulses) that reversely feeds the X-axis friction engagement member 16 twice as much as a predetermined minute amount is input to the X-axis actuator 12, and the position of the moving lens 5 at this time is detected as P2. Is V2. Further, when a pulse (for example, two pulses) for sequentially feeding the X-axis friction engagement member 16 by a predetermined minute amount is input to the X-axis actuator 12, the moving lens 5 returns to the initial position P0.

  In this way, the movable lens 5 is moved back and forth by a minute amount, and V1 and V2 are measured (actually, an integral value for a fixed time), and the difference is calculated. As shown in the figure, if V1> V2, the difference is a positive value, and if V1 <V2, the difference is a negative value. When V1> V2, the position where the detection output is maximum is in a position further forward than P0, and when V1 <V2, the position where the detection output is maximum is at a position reversely fed from P0. I understand that. If P0 is the position where the detection output is maximized, the difference between V1 and V2 is eliminated. Therefore, the control device 10 inputs, to the X-axis actuator 12, a number of pulses obtained by multiplying the difference (V1-V2) in the detection output by a coefficient (ratio between the gain of the power monitor 9 and the gain of the X-axis actuator 12). Thus, the moving lens 5 can be moved to the position P3 close to the alignment position where the detection output is maximized.

  Similarly, in the Y-axis direction, the Y-axis actuator 13 is finely fed in the forward direction and the reverse direction, and a drive pulse proportional to the difference between the detection outputs is input to the Y-axis actuator 13.

  In the vicinity of the alignment position where the detection output is maximum, a proportional relationship is seen between the distance from the alignment position and the difference (V1−V2) in the detection output, but the moving lens 5 is far from the alignment position. Then, the difference between the detection outputs becomes small, and the moving lens 5 cannot be moved to the alignment position by one wobbling. Therefore, in step S6, it is necessary to repeat the wobbling in the X axis direction and the Y axis direction. . Further, by repeatedly performing the wobbling, it is ensured that the moving lens 5 is continuously moved toward the alignment position and the detection output is maintained at the maximum.

  In this way, the positioning device 1 positions the movable lens 5 at the alignment position. However, when the power is turned off, the X-axis friction engagement member 16 and the Y-axis friction engagement member 20 are displaced. there is a possibility. Therefore, when the positioning device 1 is restarted, the control of FIG. 4 is performed again, that is, the movable lens 5 is once returned to the origin, and then the movable lens 5 is positioned at the alignment position by scanning and wobbling. .

  At this time, the control device 10 stores the number of times of pitch feed performed for positioning the moving lens 5 at the previous alignment position. Therefore, in step S2, the moving lens 5 is pitch-fed in the X direction by the number of skips equal to the stored number of skips, and then the scans in steps S3 and S4 are performed, as shown in FIG. The number of pitch feeds in the direction can be greatly reduced.

  Even when the moving lens 5 is pitch-fed by the number of skips in step S2, if the driving amount per pulse of the X-axis actuator decreases due to a temperature change or the like, the moving lens 5 is further moved to the X-axis during scanning. It may be necessary to pitch forward in the direction. In such a case, the number of pitch feeds in the X-axis direction of the moving lens 5 including the number of skips is stored in the control device 10 again. That is, the number of pitch feeds is updated each time scanning is performed.

  Further, if the skip count for pitch feeding in the X-axis direction in step S2 is set to the number obtained by subtracting a predetermined margin count from the stored pitch of the moving lens 5 in the X direction, as shown in FIG. In the scans in steps S3 and S4, after the moving lens 5 reciprocates in the Y direction by the number of margins (two times in the figure), the detection output becomes equal to or greater than the threshold value and wobbling starts.

  Thereby, even if the driving amount of the driving device 4 is increased due to a difference in temperature when the positioning device 1 is started, the detection output becomes a threshold value or more when the pitch is fed by the number of skips in step S2. Never go too far.

  In the present invention, as in the second embodiment shown in FIG. 8, the projection lens 3 can be driven as the first moving member in the Y-axis direction, and the moving lens 5 can be driven as the second moving member only in the X-axis direction. It may be movable. Thus, even if the moving member is dispersed in a plurality, there is no difference in its control method and its effect.

  Furthermore, the present invention is also applicable to a positioning device that can move only on one axis and a positioning device that can position on three or more axes.

  Further, the present invention can be applied not only to the alignment of the laser beam but also to the case where the actuator is returned to the origin based on the output of the Hall element, for example. In this case, in the wobbling, the wobbling may be terminated on the assumption that when the difference in the detection output when the minute feeding is performed is equal to or less than a predetermined threshold value, the origin is restored.

  In the present invention, instead of wobbling, a known control for driving the moving member so as to maximize the detection output, such as hill climbing control, may be applied.

The schematic diagram of the positioning device of a 1st embodiment of the present invention. Schematic of the drive device of the positioning device of FIG. The figure which shows the relationship between the movable range of the moving lens of the positioning apparatus of FIG. 1, and a detection output. FIG. 2 is a flowchart of control of the positioning device of FIG. 1. The figure which illustrates the locus | trajectory of the moving lens in the initial positioning of the positioning device of FIG. The figure which shows the principle of wobbling. The figure which illustrates the locus | trajectory of the moving lens in the positioning after the 2nd time of the positioning apparatus of FIG. The figure which illustrates the locus | trajectory of a moving lens when the frequency | count of a margin is set in the positioning after the 2nd time of the positioning apparatus of FIG. The schematic diagram of the positioning device of a 2nd embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positioning device 2 Laser diode 4 Drive device 5 Moving lens (moving member)
6 Second harmonic generator 9 Power monitor (position detection means)
10 Control device (control means)

Claims (7)

A moving member that can be moved within a movable range by the driving device; and a position detecting means that provides a maximum detection output when the moving member is at a predetermined position;
The origin of the moving member is returned to the end of the movable range,
Check the detection output every time the moving member is pitch-fed by a predetermined amount of movement, and if the detection output is equal to or greater than a predetermined threshold, execute a scan to stop the pitch feed,
Control for moving the moving member by a predetermined minute amount from the position stopped by the scan, confirming the detection output, and performing fine adjustment for moving the moving member in a direction in which the detection output is expected to increase. And a positioning device.   The positioning device according to claim 1, wherein the movement amount of the pitch feed of the moving member is ½ or less of the width of the position of the moving member at which the detection output is equal to or greater than the threshold value.   The control means stores the number of times the moving member has been pitch-fed by the scan, and when performing the scanning later, the moving member having returned to the origin is pitched by the number of skips equal to or less than the stored number of movements. The positioning apparatus according to claim 1, wherein confirmation of the detection output is started from a fed position.   The positioning apparatus according to claim 3, wherein the control unit updates the storage of the number of movements every time the scan is performed.   5. The positioning apparatus according to claim 3, wherein the skip count is a count obtained by subtracting a predetermined margin count from the move count.   The positioning apparatus according to claim 1, wherein the return to origin moves the moving member to an upper moving end. In this positioning method, a moving member that is moved within a movable range by a driving device is positioned so that the detection output of the position detection means whose detection output changes according to the position of the moving member is maximized. And
The origin of the moving member is returned to the end of the movable range,
Check the detection output every time the moving member is pitch-fed by a predetermined amount of movement, and if the detection output is equal to or greater than a predetermined threshold, execute a scan to stop the pitch feed,
Moving the moving member from the position stopped by the scan by a predetermined minute amount, confirming the detection output, and performing fine adjustment to move the moving member in a direction in which the detection output is expected to increase. A positioning method characterized by the above.

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