JPH05340742A - Measuring device of lens inclination - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a lens tilt measuring device capable of measuring the lens tilt with high accuracy by eliminating the secondary reflected light from the end face of the calibration axis. [Configuration] By providing a through hole in the train wheel setting shaft 2a,
The tilt of the lens can be measured without being affected by the secondary reflected light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens tilt measuring device for measuring the tilt of a lens such as an optical pickup.

[0002]

2. Description of the Related Art As a method of measuring the inclination of a lens of an optical pickup or the like, a method using a laser light source, an optical system, a light receiving element, etc. is generally used.

A conventional lens tilt measuring method will be described below with reference to the drawings. FIG. 2 shows an optical system for measuring the tilt of the lens of the optical pickup.
Reference numeral 3 is an optical pickup, and 4 is a lens as an object to be measured. Reference numeral 2b is a regulating shaft for fixing the position of the optical pickup and is fixed to the work table 1. 5 is a laser light source.
A beam expander 6 spreads the laser beam light. A condenser lens 10 condenses the reflected light from the surface of the lens 4 and forms an image on the light receiving element 11.

If the attitude of the lens 4 is not tilted, the reflected light 12 from the lens 4 forms an image at the center of the light receiving element 11,
If the posture is tilted, the reflected light 12 is tilted, and the image is shifted from the center of the light receiving element 11.

The inclination of the lens 4 is measured by the deviation of the image forming position. FIG. 4 shows the optical path of the reflected light from the lens 4.

[0006]

However, in the above-mentioned conventional lens tilt measuring method, in addition to the reflected light from the lens portion, the secondary reflected light which is transmitted through the lens and imaged on the end face of the regulating shaft is incident on the light receiving element. It had the drawback of being incident, causing erroneous measurements and adversely affecting the measured values.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a lens tilt measuring device which eliminates secondary reflected light from the end face of the regulating shaft and can measure the lens tilt with high accuracy. To do.

[0008]

The present invention for achieving this object is characterized in that a through hole is provided in the regulating shaft so that the laser beam light transmitted through the lens is not imaged.

[0009]

According to the present invention, by providing a through hole in the regulating shaft,
The tilt of the lens can be measured without being affected by the secondary reflected light.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an optical system for measuring the inclination of the lens of this embodiment. In the figure, 2a is a restriction shaft provided with a through hole. The laser beam light expanded by the beam expander 6 is applied to the lens 4 to be measured, then reflected from the surface of the lens 4 to be measured, and focused on the light receiving element 11 by the condenser lens 10. The laser beam light transmitted through the lens to be measured 4 is directly transmitted without being imaged on the surface of the regulation axis 2a.

As described above, according to this embodiment, the regulating shaft 2
The inclination of the lens can be measured without being affected by the secondary reflected light by the through hole provided in a.

[0013]

As described above, according to the present invention, the tilt of the lens can be measured without being affected by the secondary reflected light, and a highly accurate lens tilt measuring method can be realized.

[Brief description of drawings]

FIG. 1 is a diagram of a lens tilt measuring method according to an embodiment of the present invention.

FIG. 2 is a diagram of a conventional lens tilt measuring method.

FIG. 3 is an enlarged view of reflected light and secondary reflected light from the lens surface, which is focused on the light-receiving element surface.

FIG. 4 is an enlarged view showing a tilt of reflected light depending on a lens posture.

[Explanation of symbols]

 1 Work Table 2a, 2b Controlled Axis 4 Lens to be Measured 10 Condenser Lens 11 Photoreceptor 12 Reflected Light 13 Secondary Reflected Light

Claims (2)

[Claims] 1. A laser light source, and an optical system that spreads the beam light of the laser and irradiates the lens unit of the work with the beam light.
A tilt of the lens including a light receiving element that collects the reflected light from the lens unit and detects the condensed laser beam light, and a work table into which a regulation axis that regulates the work is inserted. measuring device. 2. The tilt measurement of a lens, characterized in that a through-hole is provided in a regulation axis of a work inserted in a work table so that a beam light transmitted through the lens is focused and is not reflected to a light receiving element. apparatus.