JPH0727544A - Lens inspecting device - Google Patents

Abstract

PURPOSE:To measure and inspect the lens angle at an optional point on the surface of a continuous lens having a complex curved surface or a discontinuous lens. CONSTITUTION:This lens inspecting device is constituted of a laser oscillating device 1 emitting a laser beam, a sample stage 7 positioning a measured object in the perpendicular direction to the laser beam, a detecting device 6 detecting the spot image position of the laser beam after it transmits the measured object, and a detection section stage 8 positioning the detecting device 6 in the perpendicular direction to the optical axis of the laser oscillating device 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens inspection device used for a video projector device, a CRT device or the like for inspecting an inclination angle of an arbitrary point of a discontinuous lens or a continuous lens.

[0002]

2. Description of the Related Art Conventionally, there has been a problem in quality because a person has visually inspected the inclination angle and the finished state of the discontinuous lens or the continuous lens alone or in a state of being assembled in the apparatus. Further, as these quantitative measuring devices, there is a stylus-type three-dimensional measuring machine, but there is a problem that the measuring object is damaged or soiled because it comes into contact with the measuring object.
In addition, a non-contact type three-dimensional measuring machine or surface shape measuring machine that obtains height information from the reflected light of laser or light can be considered, but when the measured object is glass or plastic material, it depends on the angle of the measuring point. Due to factors such as change in reflectance and reflection of transmitted light,
There is a problem in practical application. Further, the lens surface inspection apparatus using the laser interferometry has a limitation in the shape of the object to be measured,
Inspection of a discontinuous lens or a continuous lens having a complicated curved surface is difficult. Other optical lens surface measuring devices have been put into practical use, but all of them are very expensive because they require a special optical system and control and analysis are complicated.

[0003]

SUMMARY OF THE INVENTION The present invention eliminates these problems, and the angle measurement and inspection of an arbitrary point on the surface of a continuous lens or a discontinuous lens having a simple structure at a low cost and having a complicated curved surface. The purpose is to realize.

[0004]

FIG. 1 shows the overall configuration of the present invention.
Shown in. The lens inspection device of the present invention is a laser oscillation device 1.
And a detection device 6, a sample stage 7, and a detection device stage 8. 3 is an object to be measured and is shown in FIG. Either the discontinuous lens or the continuous lens shown in (b). Here, the laser beam emitted from the laser oscillator 1 is arranged so as to hit the DUT 3 perpendicularly. In addition, the detection device 6 is
The laser beam is arranged so as to strike the detection surface of the detection device perpendicularly. The detection stage 8 has a function of managing movement amount information in the XY directions. Also, the inspection object 3
And the detection device 6 are installed at a constant distance L.

[0005]

The laser beam emitted from the laser emitting device 1 is incident on the object 3 to be measured, passes through the object 3 to be measured, and then is emitted from the emitting surface. At this time, the laser beam is refracted according to the angles θx and θy of the emission surface at the measurement point of the object to be measured.
The deviation amounts Fx and Fy of the emission laser beam spot position from the optical axis of the laser oscillation device are detected from the movement amount of the detection stage 8 and the position detection information of the detection device 6, and the deviation amount F is detected.
θx and θy are detected from x and Fy and the distance L.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 is a plan view of the apparatus, and FIG. 4 is a side view.
1 is a semiconductor laser oscillator, 7 is a hollow sample stage for positioning an object to be measured at an arbitrary position, 3 is an object to be measured, 2 is a clamp device for fixing the object to be measured 4, 5
Is a total reflection mirror, 6 is a detector for detecting the spot position of the laser beam, 8 is a detector stage, and 9 is a housing to which these devices are fixed. The sample stage 7 is installed so that the DUT 3 operates in a plane perpendicular to the optical axis of the laser oscillator 1. The mirrors 4 and 5 and the detection stage 8 are arranged on the optical axis of the laser oscillation device 1 with respect to the detection device 6
The detection surface of is installed so as to operate in a vertical plane.
This operation will be described below. The laser beam emitted from the laser oscillating device 1 passes through an arbitrary measuring point of the DUT 3, is then totally reflected by the mirrors 4 and 5, and forms an image on the detection surface of the detecting device 6. When passing through the DUT 3, the laser beam is refracted by the angle (lens angle) of the emitting surface with respect to the optical axis of the laser beam. By this refraction, the detection device 6
The laser beam spot position at the height of the detection surface is XY
In order to move in the direction, the detection stage 8 is moved, and the positional deviation amount of the laser beam spot in the XY directions is measured. Since the design values of the lens angles θx and θy at the measurement point of the DUT 3 are known, the detection stage is moved in advance according to the design values, and the deviation amount from the design value is detected by the detection device 6. , Inspect the object to be measured. The relationship between the positional deviation amounts Fx and Fy of the laser spot and the lens angles θx and θy at the measurement point of the DUT 3 will be described below with reference to FIG. The laser beam that is perpendicularly incident on the incident surface of the measured object is refracted at the emission surface of the measured object at an angle of αx with respect to the normal line of the emission surface and emitted. Here, the relationship between θx and αx is
It is expressed by equation (1) according to Snell's law.

(1): n2 · sin θx = n1 · sin αx

Further, the deviation Fx of the spot position on the detection surface
Is geometrically expressed by equation (2).

(2): Fx = L · tan (αx−θx)

Here, θx: inclination angle of the emission surface of the measured object in the X direction L: distance between the measured object and the detection surface Fx: displacement amount of the laser beam spot position in the X direction

Since the distance L between the emission surface and the detection surface of the object 3 to be inspected, the refractive index n1 of air, and the refractive index n2 of the object to be measured are already known, the object to be inspected can be measured by measuring the deviation Fx of the laser beam spot position. It is possible to know the lens angle θx of. Or more X
Although the tilt angle in the direction has been described, the lens angle θy can be known also in the y direction by similarly measuring the deviation Fy of the laser beam spot position. Further, although the case where the inspection object 3 is the discontinuous lens has been described, the same measurement can be performed on the continuous lens as long as the amount of change in angle of the continuous lens surface is small. As described above, by irradiating the laser beam emitted from the laser oscillator to the DUT and measuring the refraction amount of the laser beam when passing through the DUT, it is possible to obtain a complicated curved surface that was difficult in the past. The lens angle measurement and inspection of continuous lenses and discontinuous lenses can be realized at low cost. Further, in the present embodiment, for reasons such as reducing the size of the device and lowering the center of gravity of the device,
Although the mirrors 4 and 5 are provided, this is not necessarily important to the present invention, and the mirrors 4 and 5 may be directly incorporated into the detection device without passing through them. Further, in the present embodiment, the laser oscillation device is fixed, and the DUT and the detection unit are movable, but this is not particularly limited, and for example, the laser oscillation device and the DUT are movable, and the detection unit is fixed. Also good. The detecting device may be a two-dimensional sensor using a CCD element or a PSD element, but is not particularly limited as long as it can detect two-dimensionally.

[0012]

According to the present invention, an inexpensive laser oscillating device, a camera stage, and a TV, which do not require a special optical system, are provided.
Only by properly arranging the camera, it is possible to accurately and inexpensively measure and inspect the inclination angle of the discontinuous lens or the surface of the continuous lens having a complicated curved surface at an arbitrary position.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of the present invention.

FIG. 2 is a schematic sectional view of an object to be measured.

FIG. 3 is a structural plan view showing an embodiment of the present invention.

FIG. 4 is a structural front view showing an embodiment of the present invention.

FIG. 5 is an explanatory view of the principle of the present invention.

[Explanation of symbols]

 1 Laser oscillator 3 Object to be measured 6 Detector 7 Sample stage 8 Detector stage

Claims (1)

[Claims] 1. A laser oscillating device for emitting a laser beam, a sample stage for positioning an object to be measured, a detector for detecting a spot image of a laser beam transmitted through the object to be measured, and a detector stage for positioning the detector. Be equipped with
A lens inspection device that calculates a refraction amount of a laser beam when the laser beam passes through an object to be measured from movement amount information of a detection unit stage and detection information of a detection device, and detects a lens angle of a laser beam transmission point.