JP2002250673A - Measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring instrument, made compact in size as a whole, free of heat generation, and adapted to be a bright optical system, when measuring mounting errors of a tested body by optical means. SOLUTION: This optical system is formed with intermediates parts, such as half mirrors or target mark plates abandoned for use, and an LED or a semiconductor laser is employed as a light source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a measuring device for measuring an inclination angle when a small member having a mirror surface is attached to an article by optical means to confirm and determine an allowable range. is there.

[0002]

2. Description of the Related Art Conventionally, an autocollimator has been known as a device for measuring an inclination angle when a small member having a mirror surface is attached to an article by optical means.
This principle will be described with reference to FIG. FIG. 1A is a plan view schematically showing an optical system of a general autocollimator. In the figure, reference numeral 1 denotes a tungsten lamp as a light source attached to an autocollimator main body 2. Reference numeral 3 denotes a target mark plate on which a crosshair 4 as illustrated in FIG. 1B is engraved. 5 is a half mirror attached to the main body 2 and constituted by a prism 6. 7 is an objective lens attached to the main body 2. Reference numeral 8 denotes a small member having a mirror surface, which is installed outside the main body. Reference numeral 9 denotes a screen on the main body 2 installed at the focal position of the objective lens 7. Reference lines 11 and 12 having a scale 10 as illustrated in FIG. 1C are engraved on the screen. Reference numeral 13 also denotes an eyepiece attached to the main body 2 for viewing the screen 9. In order to measure the inclination angle of the subject 8 with such an apparatus,
First, the cross line 4 and the reference lines 11, 1 are placed on the optical axis of the imaging lens 7.
Adjust so that the respective intersections of 2 are located. Then, the light source 1 is turned on. If the subject 8 is vertical and horizontal in the XY directions, the cross line 4 of the target mark plate is connected to the reference lines 11 and 12 on the screen 9 via the half mirror 5 and the objective lens 7. Projected in unison. However, when the member to be the subject 8 is tilted due to an assembling error or improper adjustment, the reflection angle changes due to the tilt of the subject, and the image of the crosshair 4 is displayed on the screen 9 as shown in FIG.
As shown in D, it is displayed shifted from the reference lines 11 and 12. The scale 10 corresponding to the deviation is read through the eyepiece 13 to determine whether or not the scale 10 is within an allowable range.

FIG. 2 is a detailed explanatory view of the optical system shown in FIG. 1A. Light from a light source 1 is converged by a condenser lens 1a and forms an image on an objective lens 7. The objective lens has a focal point on the condenser lens 1a, and the light passing therethrough illuminates the subject as a parallel light flux. FIG. 3 shows the relationship between the scale 10 of the screen 9 and the amount of tilt. When the subject 8 has a tilt of the angle θ, the measured amount L as the amount of tilt that appears on the screen 9 is given by f × tan2θ. You can ask. Therefore, if the f of the objective lens 7 and the inclination angle θ 2 as an allowable value are obtained in advance, the mounting angle of the subject 8 can be easily determined by reading the scale 10. However, this type of conventional autocollimator is generally large, and when the subject is a small member, workability is inconvenient. In particular, when measuring the mounting accuracy of a pickup lens used for compact discs, video tape recorders, laser discs (registered trademark), etc., or an object with a small mirror surface such as a prism or mirror, handling is difficult. It was inconvenient. Further, since the light source 1 is a tungsten lamp, the heat gives an unpleasant feeling to an operator who operates the autocollimator.
Further, since an intermediate member such as the target mark plate 3, the prism 6 serving as the half mirror 5, and the scale plate 9 is present in the optical system, it has been pointed out that a fatal defect that the optical system is necessarily darkened.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a measuring apparatus which has solved the above-mentioned problems. That is, miniaturization suitable for handling an object having a small mirror surface such as the pickup lens described above, and bright optics in which an intermediate such as the target mark plate 3 or the half mirror 5 is removed from the optical system as much as possible. It is an object of the present invention to provide a measuring apparatus having a system and an optical system that eliminates heat generation.

[0005]

[Embodiment 1] FIG. 4 shows a first embodiment, in which the outline of the optical system is shown as a plan view. In the figure, 15 is an LED as a light source fixed to the main body 16. Reference numeral 17 denotes an illumination optical system constituted by a condenser lens, which is attached to the main body. Reference numeral 18 denotes a mirror holding plate fixed to the illumination optical system 17, and a mirror 19 for reflecting light from the light source 15 in a substantially right angle direction is attached to a tip of the mirror holding plate at a position corresponding to the vicinity of the image forming point of the illumination system 17. Have been. Reference numeral 20 denotes another mirror fixed to the main body, which reflects light from the mirror 19,
It is directed to the objective lens 21. Reference numeral 22 denotes a subject having a mirror surface that receives light from the objective lens 21 and is set at a predetermined position outside the main body. Reference numeral 23 denotes an image forming point of the objective lens 21 which is set near the mirror 19. Reference numeral 24 denotes a magnifying lens installed near the image forming point, and forms an image on a screen 25. On this screen, a circular scale 26 is marked as shown in FIG. FIG. 6 is a detailed explanatory view of the optical system shown in FIG.
Is once formed on the image forming point 28, and goes to the objective lens 21.
The light from the objective lens irradiates the subject 22 as a parallel light flux. To check the subject 22 in such an embodiment, first, the subject is set at a predetermined position outside the main body. When the LED 15 is turned on, the light passes through the illumination optical system 17 and is reflected by the mirror 19 installed near the image point 28, and travels to another mirror 20. The light reflected again by this mirror goes to the subject 22 via the objective lens 21 and is reflected there. If the subject has no error such as tilt and is normal, the reflected light passes through the imaging lens 21 and is reflected by the mirror 20, and once at an imaging point 23 defined in the vicinity of the mirror 19. Tie the statue. This image is enlarged by the magnifying lens 24 and projected as a bright spot 27 (FIG. 5) on the center of the scale on the screen 25. The optical system described above will be further described with reference to FIG. The normal image forming point of the illumination system 17 is at the position shown in FIG. 28. In this embodiment, the mirror 19 is installed near the front side. The objective lens 21 is a mirror 1 installed near the normal imaging point.
The subject 22 is illuminated by receiving the light from the light source 9. The light reflected by the subject once forms an image at a focal position 23 defined on the optical axis of the objective lens 21. That is, the condenser lens 17
Although the normal imaging point 28 of the objective lens 21 and the imaging point 23 of the objective lens 21 originally coincide with each other (in the figure, 23 and 28 are shown shifted from each other), in this example, both the imaging points are intentionally conscious. Slightly shifted (between 23 and 28). By using an optical system that separates the light for illuminating the subject and the reflected light from the subject in this manner, the mirror 19 can be installed near the imaging point 28 of the illumination system 17, and Point 2
An optical member such as a half mirror, which is indispensable when 8 and 23 are matched, can be removed from the optical system. If the subject 22 has an error such as a tilt, the light reflected on the surface of the subject forms an image at the focal position 23 shifted by the error via the objective lens 21 and further the magnifying lens 2.
The image is projected on the screen 25 through the step 4. Since the scale 26 is written on the screen in the relationship as described in FIG. 3 as shown in FIG. 5, the inclination angle can be known by reading the relationship between the bright spot and the scale. For example, if the bright spot is at the position 29, the error is 10 due to the scale 26a.
Within seconds, if the luminescent spot is at the position 30, the measured amount can be determined to be within 20 seconds by the scale 26b.

As is apparent from the above description, one feature of this embodiment is that the mirror 19 is installed near the image forming point 28 of the condenser lens 17. As a result, the half mirror could be removed from the optical system.
That is, assuming that the half mirror 31 is installed at the regular imaging point 28 of the illumination system 17 as shown in FIG. 8, the light from the light source 15 is halved by the half mirror and travels toward the mirror 20. The light returned from the screen 2 is again halved by the half mirror.
The amount of light that reaches 5 is a quarter of the original amount. However, in this embodiment, since the half mirror has been removed,
The entire amount of light can be directed to the screen 25, and a bright optical system can be provided. The removal of the half mirror also provides the following functions. 8, the light from the illumination optical system 17 is reflected by the half mirror 31 as described above, and travels toward the next mirror 20 and the objective lens 21.
At that time, the inner surface 3 of the prism constituting the half mirror
Light is reflected also at 1a, 31b, 31c, and 31d, and the result appears as a ghost on the screen 25, which greatly affects the observation of the luminescent spot as the target mark. Can be removed.

Next, the target mark projected on the screen 25 will be described with reference to FIG. In this embodiment, a target mark plate 3 having a crosshair as shown in FIG.
Do not have. However, since an LED is employed as the light source 15, when it is turned on, a bright spot 32 as shown by a horizontal line in FIG. 9 is projected on the screen 25 as a target mark. FIG. 9A shows when a red or orange LED is used, and FIG. 9B shows when another color is used. FIG.
In A, the target mark has a circular space with protrusions 33 at four opposing positions inside. There is no theoretical proof why such an image appears on the screen, but experiments have confirmed this. With this target mark, the operator observes the target mark with an illusion that a temporary cross line connecting the projections is inside the circle. That is, the light emission of the light source itself generates the target mark.

Next, a second embodiment will be described. Figure 1
Numeral 0 is a plan view schematically showing the optical system. Reference numeral 34 denotes a light source fixed to the main body 16, which is constituted by an infrared or near-infrared laser. Reference numeral 18 denotes a mirror holding plate fixed to the main body. A mirror 19 is attached to the tip of the mirror holding plate, and reflects a laser beam in a substantially right angle direction. 20 is another mirror fixed to the main body,
Is reflected and directed toward the objective lens 21. 22
Is an object having a mirror surface and is set at a predetermined position outside the main body. 23 is an image forming point of the objective lens 21;
Is set in the vicinity. Reference numeral 24 denotes a magnifying lens, and reference numeral 35 denotes a screen constituted by an infrared viewer. When receiving infrared or near-infrared light, it converts it into green visible light and emits light. For example, commercially available channel plates and phosphors can be used. The screen is scaled as shown in FIG. A CCD 36 is used in place of the magnifying lens 24.
When the objective lens 21 is inserted into the optical system instead of
Is arranged on or near the imaging point 23.
Reference numeral 37 denotes a CCD driving circuit which transmits an electric signal to an image processing circuit 38. Reference numeral 39 denotes a CRT for receiving a signal from the image processing circuit 38, and a scale 26 as shown in FIG.
Then, the bright spot 27 from the subject 22 is projected in the same manner as the screen 25. The magnifying lens 24 and the CCD 36
Is replaced by any mechanical means. Also, C
It is obvious that the CD image sensor has no problem even if it is a position sensor such as a PSD. FIG.
Is a detailed explanatory view of the optical system shown in FIG. 10, in which light from a light source 24 is directed to an objective lens 21 and illuminates a subject 22 as a parallel light flux.

In order to measure the tilt angle of the subject 22 with the apparatus as in this embodiment, the subject 22 is installed at a predetermined position outside the main body 16 and the light source 34 is turned on. The light is reflected by a mirror 19 installed in the vicinity of an imaging point 23 and travels to another mirror 20. The objective lens 21 irradiates the subject 22 with the light.
If the subject is not tilted, the light reflected by the mirror surface once forms an image on the imaging point 23 of the objective lens 21 via the reverse path. When the magnifying lens 24 is set in the optical system, a bright point is imaged on the screen 35 by the magnifying lens. The scale on the screen 35 is obtained by multiplying the focal length f of the objective lens and the inclination angle θ by the magnification of the magnifying lens as described with reference to FIG. 3, and a luminescent spot is projected at a position 27 on the screen in FIG. Will be. As described above, since the screen 35 is an infrared viewer such as a phosphor, when receiving light such as an infrared laser, the bright spot formed on the screen 35 is colored green (550 nm). By this action, the laser light can be prevented from directly entering the eyes, and the safety standard can be satisfied even if the bright spot of the laser light is confirmed on the screen. If the subject 22 is tilted, bright points are projected at positions 29 and 30 as already described with reference to FIG. 5, so that the tilt angle may be determined by the scales 26a and 26b. When the CCD 36 is used instead of the magnifying lens 24, both are replaced by any mechanical means. Then, since the CCD is set in the vicinity of the image forming point 23 of the objective lens 21, the CCD receives the reflected light from the subject 22 and converts it into an electric signal. The drive circuit 37 receives the signal and transmits the signal to the image processing circuit 38, which transmits the signal to the CRT 39. Since a scale similar to that of FIG. 5 is displayed on the screen of the CRT in advance as an image, the relationship with the scale 26 may be determined. In addition, CRT
Displaying the coordinates of the positions 29 and 30 as "情報 seconds" as angle information on a part of the screen can be easily implemented as one of the embodiments. It is also obvious that a digital camera can be installed instead of the CCD 36. As described above, also in this embodiment, since the mirror 19 for receiving the light from the light source 34 is installed near the image forming point 23 of the objective lens 21, the half mirror as shown in FIG. 1 or 8 is removed from the optical system. You can do it. This prevents the occurrence of interference fringes due to reflection on the inner surface of the prism constituting the half mirror, and prevents the interference fringes from being displayed on the screen 35 as ghosts. Alternatively, it is possible to prevent noise due to ghost from appearing on the CRT 39 or the digital camera.

[0010]

As described above, according to the present invention, a half mirror is removed from an optical system, and instead, an optical system in which light for illuminating an object and light reflected from the object are separated is formed. LED or laser could be used. As a result, despite the removal of the half mirror, a small measuring device suitable for handling small members can be obtained, and a bright optical system without intermediates such as a target mark plate and a half mirror. Can be done. Further, since an LED or a laser beam can be used instead of the tungsten lamp, the problem of heat generation can be eliminated, and the working environment for the operator can be improved. The adoption of an LED as a light source not only saves energy, but also allows the light emission of the light source itself to act as a target mark. In addition, since an infrared viewer is used as the screen, it is possible to obtain a device that meets safety standards even when looking directly at the laser beam. Even when a CCD, a digital camera, or the like is connected to the optical system so that the image can be confirmed, it can be performed in a clear optical system free from ghost and noise.

[Brief description of the drawings]

FIG. 1A is a plan view illustrating a conventional autocollimator, B is a perspective view of a target mark plate, C is a perspective view of a screen, and D is an image on a screen.

FIG. 2 is a diagram illustrating a detailed optical system of FIG. 1;

FIG. 3 is an explanatory diagram of a tilt of a subject and a focal length f of an objective lens.

FIG. 4 is a plan view schematically showing an optical system according to the first embodiment.

FIG. 5 is an explanatory view of a screen and a scale.

FIG. 6 is a diagram illustrating a detailed optical system of FIG. 4;

FIG. 7 is a detailed explanatory diagram of the optical system shown in FIG. 4;

FIG. 8 is an explanatory diagram of a half mirror.

FIG. 9 is an explanatory diagram of a target mark projected on a screen.

FIG. 10 is a plan view schematically showing an optical system according to a second embodiment.

FIG. 11 is a view for explaining the detailed optical system of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source (tungsten lamp) 1a Condenser lens 2 Autocollimator main body 3 Target mark plate 4 Cross line 5 Half mirror 7, 21 Objective lens 8, 22 Subject 9, 25 Screen 10 Scale 13 Eyepiece 15 Light source (LED) 17 Lighting Optical system 19 Mirror 23 Imaging point 24 Magnifying lens 32 Bright spot 34 Light source (laser) 35 Screen (infrared viewer) 36 CCD 37 Drive circuit 38 Image processing circuit 39 CRT

Claims (4)

[Claims] 1. A condenser lens for connecting a light beam from a light source to an image forming point thereof, a mirror disposed near the image forming point, for reflecting the light beam in a substantially right angle direction, and receiving a light beam from the mirror to cover the light beam. An objective lens for irradiating the specimen, receiving and passing the reflected light again, and forming an image in the vicinity of a mirror provided near the imaging point, and a screen for projecting an image formed by the objective lens A measuring device configured to measure, on a screen, an image forming position of the image forming lens caused by a tilt angle of a subject, 2. A light source comprising an infrared or near-infrared semiconductor laser, a mirror for reflecting a light beam from the light source in a substantially right angle direction, and irradiating a subject with the light beam from the mirror and reflecting the light beam. An objective lens for receiving and passing light again to form an image in the vicinity of the mirror, and an image formed by the objective lens is projected, and converts infrared or near-infrared light from a light source into visible light to emit light. And a screen configured by an infrared viewer. The measurement device measures an image forming position of the image forming lens caused by a tilt angle of the subject on the screen. 3. The measuring device according to claim 1, wherein a red or orange LED is used as a light source. 4. A magnifying lens installed near an image forming position of an objective lens, and a magnifying lens installed in an optical system in place of the magnifying lens in order to magnify and project reflected light from a subject onto a screen. CCD and the signal photoelectrically converted by the CCD
3. The measuring device according to claim 2, further comprising a CRT for displaying an image via an image processing circuit.