JPH0682700A - Magnification switching device for optical equipment - Google Patents

Abstract

PURPOSE:To accurately stop a specified objective lens and to prevent the positional deviation of the objective lens at a stop position, as to a magnification switching device for an optical equipment for moving plural objective lenses and switching the magnification. CONSTITUTION:The objective lenses 11a-11d are mounted on an X stage 21. When an operator makes a key input so as to specify either of the objective lenses 11a-11d, a pulse motor M1 is driven by a CPU 31, and the X stage 21 is moved in a direction X so that the optical axis of the objective lens may be aligned with the optical axis 12 of the optical equipment main body 10. And, simultaneously, a pulse motor M2 is driven so as to move a Y stage 22 having an opening 22a formed on its central part in a direction Y. The attachment of respective objective lenses 11a-11d on the X stage 21 is improved so that the rear planes of respective objective lenses 11a-11d may not interfere with a sample positioned under the lenses when the magnification is switched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical instrument such as a microscope used for inspecting a liquid crystal panel. More specifically, one of a plurality of objective lenses having different focal lengths is individually selected to increase the magnification. The present invention relates to a magnification switching device for an optical device that performs switching.

[0002]

2. Description of the Related Art Conventionally, various optical instruments such as a microscope have been used in an optical inspection process. Among these optical devices, in a magnification switching type optical device having a plurality of objective lenses having different magnifications, the magnification is switched by an electric revolver.

An electric revolver type magnification switching device is usually constructed as follows. A rotary lens plate mounted on an optical device holds a plurality of objective lenses having different magnifications around the center of rotation thereof. An arc-shaped rack is formed on the outer peripheral surface of the lens plate, and a pinion attached to the output shaft of the motor meshes with the rack. Therefore, when the motor is driven, the lens plate is rotationally driven in the circumferential direction, and accordingly, the objective lens is rotated around the rotation center.

In addition, a sensor for individually identifying and detecting the objective lens is arranged in the rotation range of the objective lens, and the control device receiving the detection signal from the sensor determines a desired objective lens. Select the objective lens by stopping at the position,
That is, the magnification is set.

Here, this magnification switching device is provided with the following positioning means for stopping the objective lens of the selected magnification at a position where its optical axis accurately coincides with the optical axis of the optical apparatus body. Has been.

The positioning means is composed of a V-shaped groove formed on the lens plate and a ball which is provided on the optical device body side and which is fitted into the V-shaped groove when the lens plate is stopped. In this way, the selected objective lens can be accurately stopped at the desired position.

[0007]

By the way, in the case of using an optical instrument equipped with such a magnification switching device in an inspection process, it is necessary to frequently perform the objective lens switching operation. For this reason, the above-mentioned positioning means has the drawbacks that the V-grooves are easily worn, the positioning accuracy deteriorates over time, and positioning failure easily occurs when used for a long period of time.

When the V-groove is worn away, the objective lens is not positioned at the stop position and rattles, so that the observation accuracy is deteriorated. For example, when observing a pattern having 100 pitches in the vertical and horizontal directions, another pattern is observed unless the displacement of the objective lens is 50 μm or less.

Further, as described above, according to the structure in which the corresponding objective lens is detected by each of the plurality of sensors and the lens plate is stopped, the lens plate is stopped at a desired position due to a malfunction of one of the sensors. There is also a risk that an undesired overrun will occur and a different objective lens will be selected by mistake.

The present invention solves the above-mentioned problems of the prior art, and the object thereof is to reduce mechanical wear caused by the positioning of the objective lens as much as possible and to perform accurate positioning for a long period of time. It is an object of the present invention to provide a magnification switching device for an optical device that can be performed and does not cause a mistake in switching the objective lens due to a malfunction of the sensor, and as a result can significantly improve the reliability of the optical device.

[0011]

A magnification switching device for an optical apparatus according to the present invention is a magnification switching mechanism for an optical apparatus which individually selects one of a plurality of objective lenses having different focal lengths to switch the magnification. In which a plurality of objective lenses are held, and the tables can be reciprocally moved along a plane intersecting the optical axis of the optical apparatus body, and the tables are driven and controlled according to a set magnification, and the plurality of objective lenses are And a control means for stopping one of them at a position that coincides with the optical axis of the optical device body, thereby achieving the above object.

[0012] Preferably, the table is attached to a plane orthogonal to the optical axis of the optical apparatus body in an inclined posture such that one end portion orthogonal to the moving direction is higher than the other end portion, and A plurality of objective lenses are held obliquely with respect to the moving direction of the table, and their optical axes are held parallel to the optical axis of the optical device body.

Further, preferably, a second table is provided which is movable in a direction orthogonal to the moving direction of the table and has an opening at the center, and the relative movement of the table and the second table allows the table to be moved. Switch the magnification of a plurality of objective lenses.

Preferably, the table reciprocates in an oblique direction with respect to the optical axis of the optical apparatus main body, and the plurality of objective lenses are oblique with respect to the moving direction of the table and each of the light beams. The axis is held so that it is parallel to the optical axis of the main body of the optical device.

[0015]

In the above structure, when the objective lens to be selected is notified to the control means by, for example, a key input by the operator, the control means linearly drives the table, and the optical axis of the selected objective lens is the optical device main body. Stop at a position that matches the optical axis.

Here, as means for driving the table,
When the pulse motor is used, the selected objective lens can be accurately stopped at a desired position by driving the pulse motor by the number of pulses designated by the control means. Also,
The positioning means accompanied by wear as in the above-mentioned conventional example becomes unnecessary. Therefore, there is no possibility that the positioning accuracy of the objective lens will deteriorate with time.

Further, since a plurality of sensors for setting the stop position of the objective lens are not required, troubles due to malfunction of the sensors do not occur. .

Further, when a plurality of objective lenses are attached to the table as described above, when the objective lenses are moved to the magnification switching position, the lower surface of each objective lens having a different length and the measurement positioned below the lower surface of each objective lens are moved. Alternatively, the separation distance from the sample to be processed can be made substantially constant for each objective lens. Therefore, when the magnification is switched, the objective lens and the sample do not interfere with each other and both are not damaged.

[0019]

EXAMPLES Examples of the present invention will be described below.

(Embodiment 1) FIGS. 1 to 3 show Embodiment 1 of a magnification switching device of an optical instrument according to the present invention. As shown in Figure 1,
The magnification switching device includes an X stage (table) 21 that can reciprocate in the X direction, which corresponds to the horizontal direction in the drawing,
It is provided with a Y stage 22 which is capable of reciprocating in a Y direction which corresponds to the front-rear direction on the drawing orthogonal to this. The X stage 21 and the Y stage 22 are arranged below the optical device body 10, and the Y stage 22 is located above the X stage 21. The X stage 21 and the Y stage 22 both have a flat plate shape, and are attached to the Z stage 40 so as to be movable in the X direction and the Y direction in a posture in which the front end side is higher than the rear end side. The Z stage 40 can move up and down in the Z direction corresponding to the vertical direction.

The X stage 21 has four diagonal lines.
Book objective lenses 11a, 11b, 11c, and 11d are fixedly held. These four objective lenses 11a, 11
b, 11c and 11d have different magnifications and lengths. The objective lenses 11a to 11d are attached by four screw holes 21a, 21b tapped on the X stage 21,
It is performed by fastening the roots to 21c and 21d.

The inclination angles of the X stage 21 with respect to the vertical optical axis 12 of the optical device body 10 are the objective lenses 11a to 11a.
In consideration of the focal length of 1d and the length of the lens barrel, it is determined that whichever objective lens is selected does not interfere with the sample to be measured arranged below it. That is, the longest objective lens 11a is fixed at the highest position on the X stage 21, and each objective lens 11a is fixed.
The height variation of the lower surface position of 11b is reduced. Therefore, according to the configuration of this embodiment, neither the objective lens nor the sample is damaged when the magnification is switched.

Further, as shown in FIG. 3, the objective lens 11
a to 11b are attached so as to be inclined with respect to the plate surface of the X stage 21, and their optical axis directions are parallel to the optical axis 12 of the optical device body when the X stage 21 is attached to the optical device body 10. It is like this.

On the other hand, as shown in FIGS. 2 and 3, a large opening 22a is formed in the center of the Y stage 22,
The objective lens positioned below the Y stage 22 is prevented from being shielded.

A movement of the X stage 21 and the Y stage 22, that is, drive control is performed by the control device 30.
The control device 30 includes a CPU 31, which is a control center, a driver 32, a key input device 33, a RAM 34, a pulse motor M1 for driving the X stage, and a pulse motor M2 for driving the Y stage. When the operator operates the key input device 33 to specify the objective lens corresponding to the set magnification, the CPU 31 stops the objective lens at a position where its optical axis coincides with the optical axis 12 of the optical device body 10. First, the pulse motor M1 is rotated by the required number of pulses via the driver 32 to drive and control the X stage 21.

Explaining a little now, a side edge of the X stage 21 is provided with a feed mechanism composed of, for example, a ball screw 24 and a ball nut 23 that meshes with the ball screw 24, and drives the pulse motor M1. The ball screw 24 rotates, whereby the X stage 21 is smoothly moved in the X direction.

At the same time, the CPU 31 rotates the pulse motor M2 via the driver 32 to control the drive of the Y stage 22 so that the portion of the Y stage 22 other than the opening 22a does not shield the selected objective lens. . The Y stage 22 is also provided with a similar feed mechanism, and when the pulse motor M2 is driven, the Y stage 22 is smoothly moved in the Y direction. The RAM 34 stores data such as the distance between the objective lenses, which is necessary for such control, and is used as a working area.

The CPU 31 also controls the elevation of the Z stage 40, and adjusts the selected objective lens to the in-focus state with respect to the sample.

As described above, the magnification switching device of this embodiment is
Objective lenses 11a ...
The CPU 3 is provided with an X stage 21 in which 11b is arranged and a Y stage 22 in which a large opening 22a is formed in the central portion.
The configuration is such that the objective lens is selected, that is, the magnification is set, by relatively moving it in response to a command from 1. Therefore, the movement and stop operation are performed smoothly and accurately,
The positioning mechanism that causes mechanical wear over time as in the above-described conventional example is not required. Therefore, the positioning accuracy does not deteriorate with time, and the reliability of the optical device can be maintained for a long period of time.

Further, at the time of switching the magnification, the objective lenses 11a to 1a
Since the shape of holding the objective lenses 11a to 11d has been devised so that the separation distance between the lower surface of 1d and the sample is substantially constant, both the objective lenses 11a to 11b and the sample are not damaged. Therefore, also in this respect, the reliability of the optical device can be improved.

Further, since a plurality of sensors are unnecessary, troubles due to malfunction of the sensors will not occur.

(Embodiment 2) FIGS. 4 and 5 show Embodiment 2 of the magnification switching device of the optical apparatus of the present invention. This magnification switching device is configured to switch the magnification of the objective lens by moving only the X stage 21.

The X stage 21 is attached to the optical device body 10 so as to be capable of reciprocating in the X direction in an inclined posture in which the front end side is higher than the rear end side. Here, this Example 2
The X direction in is different from the X direction in the first embodiment.
That is, in this case, the X direction reciprocates in an inclined posture in which the left end side is higher than the right end side so as to move in an oblique direction with respect to the optical axis of the optical device body 10.

On the plate surface of the X stage 21, the first embodiment described above is used.
Similarly, four objective lenses 11a and 11b are held. The driving of the X stage 21 is performed by the control device similar to the above.

When the X stage 21 is reciprocally moved in the X direction in the tilted posture as described above, the distance between the lower surface of each of the objective lenses 11a to 11d and the sample becomes substantially constant at the time of switching the magnification, and the first embodiment described above is adopted. Similarly, the objective lenses 11a to 11
Both d and the sample can be prevented from being damaged.

According to the second embodiment, not only the same effects as in the first embodiment can be obtained, but also the magnification can be switched only by moving the X stage 21, so that the number of parts can be reduced and the apparatus structure can be simplified. And there is an advantage that the cost can be reduced.

The magnification switching device of the present invention as described above can be immediately applied to a microscope, but can also be applied to other optical devices. For example, the optical axis of the optical device body,
If the laser light is guided to the sample through the optical axis of the selected objective lens, the sample can be laser processed.

[0038]

As described above, according to the magnification switching device of the optical apparatus of the present invention, the mechanical wear required for positioning the objective lens can be reduced as much as possible, so that the positioning accuracy may deteriorate with time. There is no. Therefore, there is an advantage that the durability can be improved and the reliability of the optical device can be remarkably improved.

Moreover, since a plurality of sensors are not required in the operation of selecting the objective lens, troubles due to malfunction of the sensors will not occur.

In particular, according to the magnification switching device of the optical apparatus described in claims 2 to 4, since the objective lens and the sample do not interfere with each other when switching the magnification, it is possible to prevent both from being damaged. There is also an advantage that the reliability of the optical device can be improved.

Further, in particular, according to the magnification switching device of the optical apparatus described in claim 4, there is an advantage that the device configuration can be simplified and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a magnification switching device of an optical device according to the present invention.

FIG. 2 is an exploded perspective view of a moving stage according to the first embodiment.

FIG. 3 is a perspective view showing a method of attaching an objective lens to a moving stage.

FIG. 4 is a perspective view showing a second embodiment of the magnification switching device of the optical device of the present invention.

FIG. 5 is a perspective view showing a method of attaching an objective lens to a moving stage.

[Explanation of symbols]

 10 Optical Equipment Main Body 11a to 11d Objective Lens 12 Optical Axis of Optical Equipment Main Body 21 X Stage 22 Y Stage 30 Control Device 31 CPU M1, M2 Pulse Motor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tatsuya Sasaki 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Kazuo Okamura 22-22, Nagaike-cho, Abeno-ku, Osaka, Osaka Incorporated (72) Inventor Yoshihisa Iwade 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka

Claims (4)

[Claims] 1. A magnification switching device for an optical device for individually selecting one of a plurality of objective lenses having different focal lengths to switch the magnification, wherein the plurality of objective lenses are held and the A table that is capable of reciprocating along a plane that intersects the optical axis, and that table is driven and controlled according to a set magnification so that one of the plurality of objective lenses matches the optical axis of the optical device body. A device for switching magnification of an optical device, which is provided with a control means for stopping at a position for turning. 2. The table is attached to a plane orthogonal to the optical axis of the optical device body in an inclined posture such that one end portion orthogonal to the moving direction is higher than the other end portion,
The optical device main body according to claim 1, wherein the plurality of objective lenses are held obliquely with respect to the moving direction of the table, and their optical axes are parallel to the optical axis of the optical device main body. Magnification switching device. 3. A second table that is movable in a direction orthogonal to the moving direction of the table and has an opening in the center, and the plurality of objectives are provided by relative movement of the table and the second table. The magnification switching device for an optical device according to claim 2, wherein the magnification of the lens is switched. 4. The table reciprocates in an oblique direction with respect to the optical axis of the optical apparatus main body, the plurality of objective lenses are oblique with respect to the moving direction of the table, and each optical axis has the optical axis. 2. The magnification switching device for an optical device body according to claim 1, which is held so as to be parallel to the optical axis of the optical device body.