JP2002098873A - Switching device for optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switching device for an optical element which can stably perform switching operation. SOLUTION: In the initialization operation, an excitation pattern is preliminarily selected from a plurality of excitation patterns of a stepping motor 15 when a movable member 11 is in the stable position of a click mechanism 20 so that the rotor of the stepping motor 15 is set at the angle corresponding to the excitation pattern by exciting the stepping motor 15 according to the preliminarily determined excitation pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element switching device for switching an optical element arranged in an optical path in an optical device such as a microscope or an optical measuring device.

[0002]

2. Description of the Related Art Conventionally, in a microscope or an optical measuring device, in order to control the amount of light to be observed and to switch various optical paths, an optical element arranged in the optical path can be electrically and quickly switched with high precision. An element switching device is used.

In such an optical element switching apparatus, a driving mechanism such as a motor and a click mechanism are combined to drive the movable member having the optical element attached thereto by the driving means and to move the movable member moved to a predetermined position. Positioning is performed by a click mechanism.

Japanese Unexamined Patent Application Publication No. 11-84217 discloses a click mechanism for positioning a movable member with respect to a fixed member in such an optical element switching device, wherein a click groove or a click ball provided in the movable member is provided. And a click member provided on the fixed member and engaged with the click ball or a click member having an engagement hole is used. When the movable member is positioned and engaged between them, noise can be eliminated when the movable member moves, and wear on the click ball and groove edge can be significantly reduced. You can also reduce the click ball and escape from the click groove by simply deforming the click part,
It does not require a large escape torque.

In Japanese Patent Application Laid-Open No. 7-325420, a moving member having an optical element fixed and having a click member is driven via a drive transmission mechanism by a step motor driven by a predetermined drive pulse. It is moved by the contact member, the number of drive pulses of the step motor is between the contact member and the moving member, as well as the play present in the drive transmission mechanism, the interval between the optical elements to be switched, and the click member. A switching mechanism of an optical element has been proposed in which a setting is made between a case where positioning can be performed with a minimum number of pulses and a case where positioning can be performed with a maximum number of pulses, in consideration of the amount of material called into a groove.

Further, in Japanese Patent Laid-Open Publication No. Hei 10-333049, a movable member provided movably with respect to a guide portion provided in a housing and having an optical element attached thereto is driven by a driving means via a driving force transmitting means. The position detecting means detects that a click for moving and engaging the groove of the movable member to hold the movable member at a predetermined position is immediately before engagement with the groove, and the click is engaged with the groove. When the position detecting means detects that it is just before combining, the driving of the driving means is stopped, the click is dropped into the groove by the inertial force of the movable member, and the supply of the driving force of the driving means is stopped. There has been proposed an optical element switching device in which a play mechanism for expanding a moving range of a movable member due to an inertial force is provided in a driving force transmission unit.

[0007]

By the way, in a combination of such a driving means and a click mechanism, a stepping motor is often used as the driving means. This stepping motor is composed of a rotor having a permanent magnet on the outer periphery of a shaft, a plurality of magnetic poles arranged around the rotor, and a stator composed of windings wound around these magnetic poles, respectively. By changing the combination (excitation pattern) of passing the excitation current, the rotor follows the pattern by the interaction between the permanent magnet of the rotor and the electromagnet of the stator, thereby rotating the shaft.

For example, when the excitation patterns are four patterns A, B, C, and D, the excitation patterns are changed from A → B → C → D
→ A → B → C → ・ ・ ・ Right rotation, D → C → B
When it is changed in the order of → A → D → C → B →...

In this case, since the angle at which the shaft rotates each time one pattern is updated is determined by the structure of the motor, it is easy to move the movable member by a predetermined amount.

On the other hand, the click mechanism combined with such a stepping motor is configured such that when the movable member enters the click retracting range, the movable member is retracted to the stable position of the click by the force of the click spring. Positioning can be performed. Due to such features, devices which require easy control and high-precision positioning use a combination of the above-described stepping motor as a click mechanism and an actuator.

In the case where driving is performed by a stepping motor and precise positioning is performed by a click mechanism,
The movable member is moved by the driving force of the stepping motor,
When the movable member enters the retraction range of the click mechanism and the retraction force of the click exceeds the driving force of the stepping motor, the movable member is retracted to the stable position of the click. The position sensor detects whether or not it is at the position, checks the position signal of the position sensor while updating the excitation pattern of the stepping motor, and stops the movable member when the position signal of the position sensor indicates that it is at the click position. Such control is performed.

In this case, when the movable member enters the click pull-in range, the movable member is pulled into the click stable position by the click pull-in force. If the click pull-in force is strong at this time, the movable member is driven by the stepping motor. It may move more than amount. This means that the controller that controls the stepping motor recognizes the position of the movable member from the position sensor and the driving amount of the stepping motor, so that the difference between the position recognized by the controller and the actual position of the movable member is different. If the other positions are controlled by the driving amount of the stepping motor based on the click position, there is a problem that the position reference is erroneously recognized and the correct position control cannot be performed.

The present invention has been made in view of the above circumstances, and has as its object to provide an optical element switching device capable of performing a stable switching operation.

[0014]

According to the first aspect of the present invention,
A moving member that has a plurality of optical elements and selectively positions these optical elements on the optical axis; a stepping motor that drives the moving member; and any one of the optical elements provided on the moving member has an optical axis. A click mechanism for positioning the movable member in a state where the movable member is positioned above, so that when the click mechanism is at a stable position for positioning the movable member, the excitation pattern of the stepping motor becomes a specific pattern. It is characterized by setting.

According to a second aspect of the present invention, there is provided a moving member having a plurality of optical elements, for selectively positioning these optical elements on the optical axis, a stepping motor for driving the moving member, and A click mechanism that positions the movable member with any of the provided optical elements positioned on the optical axis, and a position sensor that detects that the click mechanism is at a stable position that positions the movable member. When the position sensor detects a stable position of the click mechanism by driving the movable member by the stepping motor, the stepping motor is driven by a predetermined number of steps.

According to a third aspect of the present invention, there is provided a moving member having a plurality of optical elements, for selectively positioning these optical elements on the optical axis, a stepping motor for driving the moving member, and A click mechanism provided to position the movable member in a state where any of the optical elements is positioned on the optical axis; and a position at which the click mechanism detects a predetermined position outside a stable position for positioning the movable member. A step of driving the stepping motor by a predetermined number of steps based on the predetermined position when the position sensor detects the predetermined position.

As a result, according to the present invention, the positional relationship between the excitation pattern of the stepping motor and the rotor of the stepping motor can always be matched,
It is possible to prevent the position of the movable member from being mistakenly recognized,
Further, not only the pull-in force of the click mechanism but also the driving force of the stepping motor acts as a pull-in force to the stable position of the click mechanism. Therefore, even if the spring force of the click mechanism is reduced, high-precision positioning becomes possible.

[0018]

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

(First Embodiment) FIG. 1 shows a schematic structure of an optical element switching device to which the present invention is applied.
In the figure, reference numeral 11 denotes a movable member.
It is provided so as to be able to reciprocate linearly in a direction orthogonal to the optical axis a.

A plurality (two in the illustrated example) of optical elements 12 and 13 are arranged on the movable member 11 along the moving direction.
The optical elements 12 and 13 are selectively positioned on the optical axis a by the linear reciprocating movement.

A stepping motor 15 is connected to the movable member 11 via a driving force transmission mechanism 14, and is moved according to the number of steps of the stepping motor 15. The driving force transmission mechanism 14 includes a rack gear 141 disposed along the moving direction of the movable member 11 and a pinion gear 142 connected to a rotor shaft 151 of the stepping motor 15. , The pinion gear 142 and the rack gear 14
The movable member 11 is moved linearly via the first member 1. A control circuit 16 is connected to the stepping motor 15. The control circuit 16 generates an excitation pattern for the stepping motor 15 and controls the number of steps.

A position sensor 17 is connected to the control circuit 16. The position sensor 17 is composed of a transmission type photo sensor, and detects the state of the flag 18 indicating the position of the movable member 11.

A plurality of (two in the illustrated example) click grooves 19a and 19b are formed on the side edge of the movable member 11. A click mechanism 20 is provided corresponding to the click grooves 19a and 19b. The click mechanism 20 has a roller 20b at the tip of a leaf spring 20a, and positions the movable member 11 by retracting the roller 20b into one of the click grooves 19a and 19b by the elastic force of the leaf spring 20a. Like that. That is, when the click mechanism 20 is at the stable position at the position of the click groove 19a, the optical element 12 enters the optical axis a, the flag 18 is detected by the position sensor 17, and from this state, the stepping motor 15 The movable member 1 is driven by a number of times so that the optical element 13 is on the optical axis a.
When the click mechanism 20 is moved, the click mechanism 20
b.

Next, the operation of the embodiment configured as described above will be described.

First, after turning on the power of the apparatus, an initialization operation is performed in order to recognize the position of the movable member 11 within the movable range. In this case, the stepping motor 15 is driven while monitoring the detection signal of the position sensor 17,
The click mechanism 20 enters the stable position of the click groove 19a, and moves the movable member 11 to a position where the position sensor 17 detects the flag 18.

After this initialization operation, the optical element 12
Alternatively, the control for selectively positioning the optical element 13 on the optical axis a is performed by driving the stepping motor 15 by a predetermined number of pulses. That is, the moving amount of the movable member 11 for selectively positioning the optical element 12 or the optical element 13 on the optical axis a is controlled by the number of steps for driving the stepping motor 15, and precise positioning is realized by the click mechanism 20. I do.

In the initialization operation, when the click mechanism 20 is out of the range of the click groove 19a, the movable member 11 moves only following the step feed of the stepping motor 15, but the click mechanism 20 moves. Is within the retracting range of the click groove 19a, the movable member 11
May be pulled into the stable position of the click groove 19a, and may be deviated from following the step feed of the stepping motor 15.

However, in this state, the click mechanism 20
Is pulled into the stable position of the click groove 19a, the position sensor 17 detects the flag 18, and if the position is used as a reference for switching the optical elements 12, 13, the subsequent switching control may be performed. A difference occurs between the recognized position of the movable member 11 and the position where the movable member 11 is actually located. When the optical elements 12 and 13 are switched in this state, the click mechanism 20 causes the click grooves 19a,
There is a problem in that a stable position cannot be obtained because the position does not enter the stable position of 19b.

Therefore, in the first embodiment, when the click mechanism 20 is at a stable position of the click groove 19a for positioning the movable member 11, the excitation pattern of the stepping motor 15 is set to a specific pattern. Set. Specifically, first, the rotor shaft 151 of the stepping motor 15 and the pinion gear 1 shown in FIG.
Set screw 142b for fixing the boss portion 142a
, The excitation pattern of the stepping motor 15 is excited in a predetermined pattern, the rotor of the stepping motor 15 is set at an angle corresponding to the excitation pattern at this time, and then the click mechanism 20 is positioned at the stable position of the click groove 19a. When the position sensor 17 detects the flag 18, the set screw 142b is tightened to tighten the rotor shaft 151 and the boss portion 142 of the pinion gear 142.
a is fixed.

[0030] Thus, in this manner, in the initializing operation, when the movable member 11 is in a stable position of the click mechanism 20, among a plurality of excitation pattern of the stepping motor 15, leave decide to advance what pattern ,
Since the rotor of the stepping motor 15 is set to an angle corresponding to the excitation pattern by exciting the stepping motor 15 with the determined excitation pattern, the movable member 11 is driven by the click mechanism 20 by the retraction force of the click mechanism 20. Even if the excitation pattern of the stepping motor 15 is drawn into the stable position and the positional relationship between the excitation pattern of the
After the completion of the initialization operation, the position of the movable member 11 recognized by the control circuit 16 and the actual position of the movable member 11 can be matched. Thus, when the movable member 11 is at the stable position of the click mechanism 20 and stops driving the stepping motor 15, a predetermined specific excitation pattern is used, so that the stepping motor 1 is always turned on.
Since the positional relationship between the excitation pattern 5 and the rotor of the stepping motor 15 can be matched, it is possible to prevent the position of the movable member 11 from being erroneously recognized. In addition, not only the pulling force of the click mechanism but also the driving force of the stepping motor 15 acts as a force for pulling the click mechanism 20 to a stable position. Therefore, even if the spring force of the click mechanism 20 is reduced, highly accurate positioning is possible. The subsequent switching operation of the optical elements 12 and 13 is stable, and accurate positioning can be performed.

Further, within the retracting range of the click mechanism 20, it is possible to prevent the retracting direction by the spring force of the click mechanism 20 and the retracting direction by the magnetic force of the stepping motor 15 from competing with each other.
Vibration can be suppressed.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
Will be described. In this case, the schematic configuration of an optical element switching device to which the second embodiment is applied is the same as that of FIG.

In the second embodiment, in the initialization operation, when the click mechanism 20 enters the stable position of the click groove 19a and the position sensor 17 detects the flag 18, the control circuit 16 further activates the stepping motor 15. Advance by a predetermined number of pulses, and then stop. In this case, the number of steps for moving the stepping motor 15 is set in advance to the number of steps required for the click mechanism 20 to move from a position immediately before entering the click groove 19a into the retracted range to the stable position of the click groove.

In this case, the movable member 11 is pulled into the stable position of the click mechanism 20 by the retraction force of the click mechanism 20, and the positional relationship between the excitation pattern of the stepping motor 15 and the rotor of the stepping motor 15 is shifted. Also, by increasing the number of steps of the stepping motor 15 by the deviation, the position of the movable member 11 recognized by the control circuit 16 at the time of completion of the initialization operation matches the actual position of the movable member 11. be able to. Thereby, after the initialization operation, the positional relationship between the excitation pattern of the stepping motor 15 and the rotor of the stepping motor 15 can be always matched, so that the position of the movable member 11 can be prevented from being erroneously recognized. . Also, not only the pulling force of the click mechanism 20 but also the driving force of the stepping motor 15 acts to draw the click mechanism 20 to a stable position.
Even if the spring force of the click mechanism 20 is reduced, high-precision positioning becomes possible, and the subsequent switching operation of the optical elements 12 and 13 is stabilized, and accurate positioning can be performed.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
Will be described. FIG. 3 shows a schematic configuration of the third embodiment, and the same parts as those in FIG. 1 are denoted by the same reference numerals.

In this case, as shown in FIG.
When the click mechanism 20 is in a stable position at the position of the click groove 19a by the movement of the optical element 12 and the optical element 12 is on the optical axis a, the position sensor 17 does not detect the flag 18 and the stepping motor 15 When the movable member 11 is moved by the predetermined number of steps to move the optical element 13 so as to enter the optical axis a, the click mechanism 20 is brought into the stable position of the click groove 19b, and the position sensor 17 18 is configured to be detected.
That is, in this case, when the click mechanism 20 is located between the stable position of the click groove 19a and the stable position of the click mechanism 19b, the terminal 18a of the flag 18 is detected by the position sensor 17. I have. Then, using the detected position of the terminal 18a as a reference position, the number of steps A of the stepping motor 15 until the optical element 12 enters the optical axis a from the terminal 18a and the click groove 19a enters the stable position of the click mechanism 20, and Terminal 18
The number of steps B of the stepping motor 15 from when the optical element 13 enters the optical axis a to when the click groove 19b enters the stable position of the click mechanism 20 is set.

In such a configuration, first, after the power of the apparatus is turned on, an initialization operation is performed in order to recognize the position of the movable member 11 within the movable range. In this case, it is determined from the signal of the position sensor 17 whether the flag 18 is detected. Here, the position sensor 17 sets the flag 18
Is detected, the position sensor 17 sets the flag 1 in the direction in which the optical element 12 enters the optical axis a (rightward in the figure).
If the optical element 13 has not been detected, the movable member 11 is moved by the stepping motor 15 in the direction in which the optical element 13 enters the optical axis a (left direction in the figure), and the terminal 18a of the flag 18 is searched. If the position sensor 17 detects the terminal 18a of the flag 18, for example, the optical element 1
When switching 2 to the optical axis a, the stepping motor 15 is advanced by the preset number of steps A, the movable member 11 is moved to position the optical element 12 on the optical axis a, and the click mechanism 20 is clicked. The groove 19a is positioned at a stable position. When switching the optical element 13 on the optical axis a, the stepping motor 15 is advanced by the preset number of steps B, and the movable member 11 is moved to position the optical element 13 on the optical axis a. The mechanism 20 is positioned at a stable position of the click groove 19b.

Accordingly, in this manner, in the initialization operation, the terminal 18 of the flag 18 is detected by the position sensor 17.
a, and if this terminal 18a is detected, the stepping motor 15 is advanced by a preset number of steps based on this position, and the movable member 11 is moved to move the optical elements 12, 13 on the optical axis a. Along with
Since the click mechanism 20 is positioned at the stable position of the click grooves 19a and 19b, the position of the movable member 11 recognized by the control circuit 16 at the time of completion of the initialization operation and the position of the movable member 11 actually exist. Can be matched. Thereby, after the initialization operation, the excitation pattern of the stepping motor 15 and the stepping motor 15
Since the position relationship with the rotor can be matched,
The position of the movable member 11 can be prevented from being erroneously recognized, and the subsequent switching operation of the optical elements 12 and 13 is stabilized, and accurate positioning can be performed.

In the above-described first to third embodiments, an example in which two optical elements 12 and 13 are switched has been described. However, the same applies to the case where the number of optical elements is two or more. It can be implemented in the same way by means. Further, in the first to third embodiments described above, the device in which the movable member 11 moves linearly has been described. However, the same effect can be obtained by the same means even when the movable member 11 rotates. In addition, the first
In the third to third embodiments, the position sensor 17 has been described as a transmissive photo sensor. However, similar effects can be obtained by similar means using a position sensor such as a reflective photo sensor, a magnetic sensor, or a microswitch. can get.

[0040]

As described above, according to the present invention, it is possible to prevent the position of the movable member from being erroneously recognized.
High-precision positioning is possible, and within the retraction range of the click mechanism, the retraction direction by the spring force of the click mechanism and the retraction direction by the magnetic force of the stepping motor can be prevented from competing with each other.
Vibration can be suppressed.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a connection configuration between a stepping motor and a driving force transmission mechanism used in the first embodiment.

FIG. 3 is a diagram showing a schematic configuration of a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Movable member 12 ... Optical element 12.13 ... Optical element 13 ... Optical element 14 ... Driving force transmission mechanism 141 ... Rack gear 142 ... Pinion gear 142a ... Boss 142b ... Set screw 15 ... Stepping motor 151 ... Rotor shaft 16 ... Control Circuit 17: Position sensor 18: Flag 18a: Terminal 19a. 19b: click groove 20: click mechanism 20a: leaf spring 20b: roller

Claims (3)

[Claims] A moving member that has a plurality of optical elements and selectively positions the optical elements on an optical axis; a stepping motor that drives the moving member; A click mechanism for positioning the movable member in a state where any one is located on the optical axis, and when the click mechanism is at a stable position for positioning the movable member, the excitation pattern of the stepping motor is specified. A switching device for an optical element, wherein the switching device is set to have a pattern. 2. A moving member having a plurality of optical elements and selectively positioning these optical elements on an optical axis; a stepping motor for driving the moving member; A stepping motor comprising: a click mechanism for positioning the movable member in a state where one of them is positioned on the optical axis; and a position sensor for detecting that the click mechanism is at a stable position for positioning the movable member. Wherein the step sensor drives the stepping motor by a predetermined number of steps when the position sensor detects the stable position of the click mechanism by driving the movable member. 3. A moving member that has a plurality of optical elements and selectively positions these optical elements on an optical axis; a stepping motor that drives the moving member; A click mechanism that positions the movable member in a state where one of them is positioned on the optical axis, and a position sensor that detects a predetermined position outside a stable position where the click mechanism positions the movable member, An optical element switching device, wherein when the position sensor detects the predetermined position, the stepping motor is driven by a predetermined number of steps based on the predetermined position.