JPH0446182Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is a precision optical instrument such as a spectrophotometer that requires optical elements such as slits, mirrors, filters, or shutters in the optical path of the optical system of the instrument. The invention relates to a switching mechanism that can be turned on and off depending on the situation.

(Prior art) When switching an optical element is used to switch between two states, such as switching on/off of a luminous flux or switching a filter, if the positional accuracy of the optical element is not required, the switching It is not necessary to use a driving means capable of precise position control such as a stepping motor, and a solenoid can also be used.

(Problem that the invention aims to solve) In precision optical instruments such as spectrophotometers, when an optical element is moved in and out of the optical path of the optical system or switched, the optical element must have appropriate accuracy and reproducibility. is required. If precision and reproducibility are required for one of the two conditions,
Exactly the same control mechanism as in the case where precision and reproducibility are required for both states is required.

Furthermore, when using a solenoid, it is difficult to provide a large drive stroke, and there are also problems in terms of service life.

An object of the present invention is to provide a switching mechanism that can achieve positional accuracy without precise positional control when switching an optical element between two or more states.

(Means for Solving the Problems) In the present invention, for one of two or more states, the optical element is brought into contact with the contact member and is pressed by a tension spring, whereby the first state is The positional accuracy is obtained and used as a substitute for the origin position detection means. The other states are switched and set using the contact state as the origin.

That is, in the switching mechanism of the present invention, an optical element that can be switched to two or more positions is mounted in a direct axis format on the rotating shaft of a motor, and a contact member that abuts the optical element is provided at a first position of the optical element. and the optical element is biased in the direction of pressing against the abutting member, and when the motor stops energizing, the optical element is pulled back to the position of the abutting member, so that movement of the optical element by motor drive is not hindered. It is equipped with a strong tension spring.

(Embodiment) FIG. 1 shows an example in which the present invention is applied to a chromatographic scanner that uses a rotating slit disk and can switch between flying spot scanning and linear scanning. Figure A is a plan view;
Figure B is a front view, and Figure C is a left side view.

2 is a slit disk, and the slit disk 2 has a spiral slit slot 4 for flying spot scanning and rectangular slit holes 6-1 to 6 for linear scanning.
-3 is provided. Slit disk 2 is boss 9
It is attached to the rotating shaft of the stepping motor 8 via.

Reference numeral 10 denotes a widthwise slit plate to which the present invention is applied, and is provided with a slit hole 12 that defines the width direction of the light beam during flying spot scanning. The widthwise slit plate 10 is bonded to a support plate and attached to the rotating shaft of a stepping motor 14 via a boss.

Both stepping motors 8 and 14 are mounted on an L-shaped plate 16 for motor mounting. A guide plate 20 is attached to the surface of the L-shaped plate 16 via a guide stand 18. A portion of the slit disk 2 passes through the gap between the guide stand 18 and the guide plate 20, thereby preventing the slit disk 2 from warping.

The tip of the guide plate 20 is bent, and a sponge 2 with a thickness of about 1 mm or less is attached to the bent part.
2 is attached, and the tip of this guide plate 20 serves as an abutment member for the width direction slit plate 10 in the first position state.

The widthwise slit plate 10 has a widthwise slit plate 1.
A tension spring 24 is applied to bias the guide plate 20 in the direction of pressing the bent portion at the leading end of the guide plate 20.

Note that 26 is an element for detecting the origin of the slit disk 2.

The state shown in the figure is a state in which flying spot scanning is executed. The spiral slit slot 4 of the slit disk 2 is on the optical path, and the slit plate 10 in the width direction
is set so that it comes into contact with the bent end portion of the guide plate 20 and the center of both the vertical and horizontal directions of the widthwise slit 12 is on the light beam. No current is passed through the stepping motor 14. The width direction slit plate 10 has its radial position fixed by the shaft of the motor 14, and is in contact with the bent portion of the tip of the guide plate 20 while being pulled by the tension spring 24. Then, the width direction slit plate 1
The axial and rotational positions of 0 are fixed.
In other words, the center of the widthwise slit hole 12 is located on the light beam, and moreover, on the exit slit imaging position.

Next, when switching the measurement mode from flying spot scanning to linear scanning, remove the widthwise slit hole 12 from the optical path, select any of the rectangular slits 6-1 to 6-3 on the slit disk 2, and select the light beam. move to position. Width direction slit hole 12
To remove the lens from the optical path, a current is applied to the stepping motor 14 and the stepping motor 14 is rotated clockwise by the required angle as shown in FIG. At this time, the stepping motor 14
The widthwise slit plate 10 stops when the rotational force (torque) of the tension spring 24 is balanced with the tension force of the tension spring 24. That is, the strength of the tension spring 24 and the type of motor 14 are selected in this manner. Once the widthwise slit plate 10 has been moved to a position where linear scanning does not interfere with measurement, the stepping motor 14 is continuously energized by current.
The width direction slit plate 10 is maintained so as not to come down by using the holding torque when stationary.

To return to flying spot scanning, rotate the stepping motor 14 counterclockwise little by little, and when the widthwise slit plate 10 reaches a position slightly before it hits the sponge 22 at the bent end of the guide plate 20, the motor should be turned off. The current flowing through 14 is cut off, and the widthwise slit plate 10 is fixed in place again by the tension spring 24. By doing so, it is possible to reduce the impact when the width direction slit plate 10 hits the sponge 22 at the moment after the current is turned off.

Further, if the power is turned off while the motor 14 is energized and the width direction slit plate 10 is moving, the width direction slit plate 10 will not remain in the middle position, but will be moved by the force of the tension spring 24. Return to the initial position indicated by . That is, the widthwise slit plate 10 is initialized to the position where it contacts the sponge 22 even when the power is turned on.

Figure 2 shows an example in which the present invention is applied to optical path switching by moving a plane mirror in and out.
Figure A is a plan view, and Figure B is a front view. A rotary plate 32 with a mirror 30 attached thereto is attached to a rotating shaft of a motor 34 via a boss. mirror 3
The abutment plate 36 is provided such that the 0 abuts the abutment plate 36 via the sponge 34 in its first position. The rotary plate 32 is biased toward the abutment plate 36 by a tension spring 38 .

When the rotating plate 32 is in contact with the contact plate 36, the light beam 40 is reflected by the mirror 30, and the light beam 40 is reflected by the symbol 40.
Proceed in the direction of a. Furthermore, when the motor 34 is energized and the rotating plate 32 is rotated clockwise to the position shown by the chain line in FIG.
goes straight in the direction of symbol 40b.

FIG. 3 shows an example in which the present invention is applied to a filter switching mechanism, in which FIG. 3A is a front view and FIG. 3B is a plan view.

Two types of filters 42a and 42b are attached to a filter mounting plate 44, and the filter mounting plate 44 is attached to the rotating shaft of a motor 46 via a boss. A contact plate 50 is provided so that one side of the filter mounting plate 44 contacts the contact plate 50 via the sponge 48. A tension spring 52 is applied to the filter mounting plate 44 to bias the filter mounting plate 44 in the direction of the abutment plate 50.

Assuming that a light beam passes through the filter 42a in the state shown in the figure, to switch the filter, the motor 46 rotates the filter mounting plate 44 clockwise in the figure, and moves the filter 42b to the light beam position. In this case, if the dimensions of the filters 42a and 42b are made larger than the size of the light beam passing through the light beam position, this can be achieved without any problem.

In the embodiment shown in FIG. 3, in order to easily fix the filter 42b at the light beam position, an abutting plate 50a and a sponge 48a are provided which abut on the other side of the filter mounting plate 44, and a tension spring 52 is provided.
A tension spring 52a that biases in the opposite direction may be further applied.

(Effect of the invention) In the switching mechanism of the invention, for one of two or more states, the optical element is brought into contact with the contact member and is pressed by the tension spring,
This increases the accuracy of the first position, which is used as a substitute for the origin position detection means, and the other states are switched and set using the contact state as the origin. As a result, when the optical element is moved in and out or switched between two states, there is no need to detect the origin before the movement, and a mechanism for detecting the origin is not required.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, in which Fig. 1A is a plan view, Fig. 1B is a front view, and Fig. 1C is a left side view. FIG. 2 shows another embodiment, in which FIG. 2A is a plan view and FIG. 2B is a front view. FIG. 3 shows still another embodiment, in which FIG. 3A is a front view and FIG. 3B is a plan view. 10... Width direction slit plate, 14, 34, 46
...Motor, 20...Guide plate, 24, 38, 5
2...Tension spring, 32...Rotating plate, 36,50
...Abutting plate, 44...Filter mounting plate.

Claims (1)

[Scope of utility model registration request] An optical element that can be switched to two or more positions is mounted in a direct axis format on the rotating shaft of the motor, a contact member that abuts the optical element is provided at a first position of the optical element, and the optical element has the The optical element is provided with a tension spring that is biased in a direction to press it against the abutting member, and that when the motor stops energizing, pulls the optical element back to the position of the abutting member, and has a strength that does not impede movement of the optical element by motor drive. Element switching mechanism.