JPH0420910A - Simple automatic focus measuring optical instrument - Google Patents

Abstract

PURPOSE:To make rapid observation by setting a sample to a stage in an arbitrary stage position, then resetting this stage to a measuring position in the case of continuous measurement o the samples of the same kind. CONSTITUTION:The stage 14 is set in a reference position and the sample S is imposed on the stage 14. A user focuses the sample S manually by using a lever 28 for roughly moving the stage. The focused position of the stage 14 is then stored as the measuring position for the sample S in a memory means. The sample S is subjected to the prescribed observation or measurement, such as inspection. The stage 14 is lowered after the end of the measurement and the sample S is exchanged with the next sample of the same kind. The stage 14 is exactly moved to the position storing the stage 14 by pushing an autofocusing key 20 of an operating key box 19. The above-mentioned operations are repeated and the measurement of the samples of the same kind is executed simply by pushing the autofocusing key 20.

Description

[Detailed description of the invention] [Industrial application field]

The present invention particularly relates to a simple autofocus optical measuring device suitable for continuously observing or inspecting the same type of sample.

[Conventional technology]

Autofocus devices used in autofocus mirrors include those that employ a contrast method using a CCD camera, and those that employ a reflective active method that uses a semiconductor laser or the like. All of the above autofocus devices include a sensor unit that detects the sample position and converts it into an electrical signal, a stage drive motor that moves the stage on which the sample is placed, and a signal from the sensor that is fed back to the stage drive motor. The main device configuration is a control unit that controls the Therefore, the autofocus device has the ability to accurately focus on various samples.

[Problem to be achieved by the invention]

However, since the autofocus device itself is complicated, the microscope equipped with the autofocus also has a complicated configuration, and therefore, there is a problem that the microscope has to be expensive. The present invention has been made to solve the above problems, and
It is an object of the present invention to provide a simple autofocus optical measuring device that has a simple configuration and can therefore be manufactured at low cost.

[Means to achieve the task]

The present invention provides a simple autofocus optical measuring instrument, which provides a stage driving means for moving the stage forward and backward in the optical axis direction of the optical system, a reference position setting means for setting the reference position of the stage, and a sample mounted on the stage. The above object has been achieved by providing a storage means for storing the stage measurement position where the focus of the optical system coincides, and a return means for returning the stage to the measurement position 1 by the stage drive means.

[Action and effect]

In the present invention, the stage is moved in the direction of the optical system, the focus of the optical system is brought into alignment with the sample placed on the stage, and the deviation from the reference position at that time is stored as the measurement position of the stage. Even when another sample is set on the stage at an arbitrary stage position after the measurement of the sample is finished, the stage can be reliably returned to the measurement position. Therefore, especially when measuring the same type of sample continuously, by setting the sample on the stage at an arbitrary stage position and then returning the stage to the measurement position, it is possible to quickly and accurately measure the same type of sample. Since the sample can be focused, the sample can be efficiently and continuously measured. Further, according to the present invention, since a sensor section and a feedback control section are not required, the configuration of the autofocus device can be simplified, and as a result, a simple autofocus optical measuring device can be manufactured at low cost.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. A simple autofocus optical microscope, which is an embodiment of the present invention, has a microscope main body shown in a front view in FIG. 1, and an operation key box shown in a perspective view in FIG. The microscope main body 10 includes an optical system having three objective lenses 12 each having a different magnification, and a stage I4 located below the objective lenses 12 on which the sample S is placed. A pulse motor (stage driving means) 16 is attached to the stage 14, and the stage 14 is driven by the objective lens 1.
It is movable up and down in two directions. Further, the microscope main body 10 is provided with a limit switch (reference position setting means) 18, and the limit switch I8 sets the position at which the stage 14 has descended, for example, to the reference position (origin) of the stage 14. It has been possible to set it as The simple autofocus optical microscope of this embodiment also includes a storage means (not shown) for storing the position 1 of the stage 14, where the focus of the objective lens matches the sample S placed on the stage 14, as the measurement position. ) is provided. This storage means is configured to store the measurement position as a pulse number corresponding to the amount of deviation of the stage 14 from the reference position. In addition, after exchanging the sample S at an arbitrary stage position, the above-mentioned microscope has the exchange position and the above-mentioned measurement position! output a number of pulses corresponding to the number of pulses to the pulse motor 16, and
a return means (
(not shown). The operation key box 19 shown in FIG. A stage fine movement knob 22 is provided for sub-adjustment. In addition, the two microscopic mirror bodies 10 have a lens barrel fixing screw 23, a mirror I! 'i
It also includes a rate switching knob 24, a revolver fixing screw 26, a stage coarse movement lever 28, a -axis handle 30, a display panel 32, a lighting switch 34, and the like. Next, the operation of this embodiment will be explained with reference to the flowchart shown in FIG. First, turn on the power, press the origin confirmation key of the operation key box 19, and lower the stage 14 to the limit switch 18 to set the reference position of the stage 14 (steps 41 to 43). The sample S is placed on a predetermined position on the stage 14 (step 44), and the sample S is manually focused using the stage coarse movement lever 28. This focusing may be initially performed using a low magnification objective lens. , and finally at high magnification (step 45). Normally, microscope objective lenses are designed to focus at the same position regardless of the magnification, so if you focus with a high-magnification objective lens with a shallow depth of focus, you can then focus on a low-magnification objective lens with a shallow depth of focus. Even when switching to , the depth of focus is deep, so you can always reproduce an accurately focused state. After the above focusing is completed, the focused position of the stage 14 is stored in the storage means as the measurement position for the sample S. Specifically, the number of pulses required to move the stage 14 from the reference position to the measurement position 1 using the pulse motor 16 is stored (step 46).
). After finishing the specified measurement (observation or inspection) on the sample S, the stage 14 is lowered to an arbitrary position, and the next sample S of the same type is exchanged at that position (steps 47 to 47).
48). After completing the exchange of the same type of sample, press the autofocus key 20 in one of the operation key boxes, and the pulse motor 16
is driven, the stage 14 accurately moves to the measurement position stored as the number of pulses starting from the reference position, and returns (step 50).The stage 14 is placed on the stage 14 which has returned to the measurement position. Measurement (observation or inspection) is performed on the sample S (step 51), and step 4
Return to 7. Thereafter, by repeating each operation of steps 47 to 51, the same type of sample can be automatically focused by simply pressing the autofocus key 20 after replacing the sample. Continuous measurements can be made quickly. In addition, when a series of measurements on the same type of sample is completed,
By returning from step 51 to the stent 44 and exchanging the different sample with the stent, continuous measurements can be quickly performed on the different sample in the same manner as described above. Therefore, when inspecting many samples of the same type, such as when observing or inspecting samples at a factory or other site,
If you first focus by moving the stage up and down and memorizing the stage position at that time, when you change the sample, you can focus accurately by simply moving the stage to the memorized position. Therefore, it becomes possible to carry out a diagnosis or inspection quickly. As described above, according to this embodiment, the autofocus mechanism can be formed without using a sensor section or a feedback control section, so it is possible to have an autofocus optical mirror with a simple configuration. As a result, it becomes possible to provide an inexpensive autofocus optical microscope. Although the present invention has been specifically described above, it goes without saying that the present invention is not limited to what was shown in the above embodiments, and can be modified in various ways. For example, as a simple autofocus optical measuring machine,
The present invention is not limited to the optical microscope shown in Example 81, but may also be a projection inspection machine.

[Brief explanation of drawings]

FIG. 1 is a front view showing the main body of a simple autofocus optical folding microscope that is an embodiment of the present invention, and FIG. 2 is a perspective view showing the operation key box of the simple autofocus optical WL mirror. , FIG. 3 is a flowchart for explaining the operation of the embodiment. DESCRIPTION OF SYMBOLS 10...Microscope body, 12...Objective lens, 14...Stage, 16...Pulse motor, 18...Limit switch, 1...Operation key box, 20...Autofocus key 28... Stage coarse movement lever

Claims (1)

[Claims] (1) A stage driving means for moving the stage forward and backward in the optical axis direction of the optical system, a reference position setting means for setting the reference position of the stage, and a stage measurement position where the focus of the optical system matches the sample placed on the stage. storage means for storing
and a return means for returning the stage to the measurement position by the stage drive means.