JPH08247953A - Inspecting instrument for surface of spherical body - Google Patents

Abstract

PURPOSE: To enable inspecting of the character of the overall surface of a spherical body to be inspected handily without altering an optical system according the size of a steel ball. CONSTITUTION: This apparatus has an elliptic mirror 13 which has as a mirror surface a specified area 12 of the internal surface of a curved surface obtained by turning a long axis 11 of an ellipse 10 having a first focus A and a second focus B and a rotary mirror 18 allowed to turn or oscillate as arranged at a specified position on the long axis 11 while a flat mirror 16 is provided on one end face 15 of the axis 18 of rotation. Light from a laser diode 1 is admitted into a spherical body 6 to be inspected via the flat mirror 16 and the elliptic mirror 13. The center of the spherical body 6 to be inspected is set to coincide with the second focus B so that light enters the spherical body 6 to be inspected from the vertical direction. Therefore, the light incident into the spherical body 6 to be inspected reverses and the quantity of the light passing through a slit 5 by way of a beam splitter 21 is converted to electricity by a photodetector 3 to inspect the properties of the surface of the spherical body 6 to be inspected by a spherical body property judging means 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sphere surface inspection device, and more particularly to a sphere surface inspection device for optically inspecting the surface properties of a sphere such as a steel ball.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 13, a spherical surface inspecting apparatus of this type has a set of a plurality of light emitting elements 51 and light receiving elements 52 arranged at equal angles in a semicircular shape. The provided semicircular array 53 is provided in the circumferential direction of a steel ball 54, which is a sphere to be inspected, and the steel ball 54 is centered around the support shaft 55.
It is known that the surface texture of the steel ball 54 is determined based on the electric signal level output from the light receiving element 52 by rotating the arrow mark in the direction of the arrow Y (hereinafter referred to as "first conventional example"). .

In the first conventional example, as shown in FIG. 14, the light emitted from the light projecting element 51 is reflected on the surface of the steel ball 54, and the reflected light is then the light projecting element 51. The light is received by the light receiving element 52 arranged at a constant angle α. Then, the light passing through the light receiving element 52 is converted into an electric signal by a photoelectric conversion element such as a photodiode (not shown) and output through an amplifier and a gain adjusting circuit (not shown), and the steel ball is output based on the output signal level. The surface properties of 54 are judged, and it is inspected whether or not the steel ball 54 is free from defects such as scratches.

Further, as another conventional example of the spherical surface inspection apparatus, as shown in FIG. 15, illumination light 56 (emitted from an illuminator or the like) is applied to the surface of a steel ball 54 rotating in the arrow Z direction. It is known that a light is reflected by the surface of the steel ball 54 and is condensed by using a convex lens 57 and the image is formed on a photoelectric conversion element 58 such as a CCD (charge coupled device). (For example, JP-A-56-586)
43, JP-A-56-58644; hereinafter referred to as "second conventional example").

In the second conventional example, the photoelectric conversion element 58 converts the amount of light into an electric signal, and the surface quality of the spherical surface is judged based on the output signal level of the electric signal.
The steel balls 54 are inspected for defects. In addition, the second
In the conventional example, by performing skew rotation of the steel ball 54 at a predetermined angle, the surface texture of the entire surface area of the steel ball 54 can be inspected even with the photoelectric conversion element 58 having a small light receiving area.

[0006]

However, in the first conventional example, the diameter dimension of the steel ball 54 (hereinafter,
Since it is necessary to inspect the surface texture of the steel balls 54 with relatively the same sensitivity relative to the "steel ball size"),
There has been a problem that the sensitivity for detecting defects of the steel balls 54 has to be adjusted every time the size of the steel balls changes.
That is, the allowable size of a steel ball defect varies depending on the steel ball size, and for the steel ball 54 having a small steel ball size, the allowable defect size such as a scratch needs to be set small, while For the steel ball 54 having a large ball size, the allowable defect size may be set to be large according to the steel ball size. Therefore, conventionally, in order to prevent a decrease in yield and the like, sensitivity adjustment according to the steel ball size has been performed in order to set an allowable defect size according to the steel ball size. Therefore, in the above-mentioned first conventional example, it is necessary to perform balancing adjustment and inspection of variations in sensitivity for converting the amount of light received by the photoelectric conversion element into an electric signal for each steel ball size. There was a problem that it took time.

Further, in order to improve the detection resolution of defects in the surface texture, it is necessary to bring the light receiving elements 52 as close as possible to the surface of the steel ball 54 so that the field of view of each light receiving element 52 becomes narrow. In the first conventional example, there is a problem that it is necessary to prepare in advance a plurality of circumferential arrays 53 adapted to the steel ball size. That is, in order to bring the circumferential array 53 as close as possible to the surface of the steel ball 54 and inspect the surface texture of the steel ball 54 with high accuracy, a plurality of types of circumferential arrays having different pitch circle diameters according to the steel ball size are used. Since it is necessary to manufacture 53 and select a desired circumferential array 53 according to the size of the steel ball to set the apparatus, there is a problem that preparation for measurement takes time and effort.

On the other hand, in the second conventional example, the face-to-face distance of the steel ball to be inspected by the imaging optical system (the first face-to-face distance a between the steel ball 54 and the lens 57 and the convex lens 57 and the photoelectric conversion element 58). And the second surface distance b) and the image magnification (b /
Since a) is determined, it is relatively easy to adjust the relative distances between the first face-to-face distance a and the second face-to-face distance b for the steel balls 54 having different steel ball sizes. Although easy, it is difficult to uniformly illuminate the surface of the steel ball 54 to obtain an image of uniform brightness. That is, even if the surface of the steel ball 54 is irradiated with the illumination light, the angle of reflection from the surface of the steel ball 54 after being incident on the surface of the steel ball 54 is largely different between the central portion and the peripheral portion of the illumination light. It becomes difficult for light to enter the lens 57, and an image of uniform brightness cannot be obtained. Therefore, as shown by the chain double-dashed line in FIG. 15, a diffusion glass 59 is provided on the optical path of the illumination light to irradiate the surface of the steel ball 54 from multiple directions, and the reflected light is scattered in all directions to perform photoelectric conversion. It is conceivable to form an image on the element 58. However, when the diffusion glass 59 is provided, the illumination light is diffused over a wide range on the surface of the steel ball.
The convex lens 57 has a poor light-collecting property, and it is difficult to inspect a steel ball surface in a substantially wide range.

Further, in order to change the detection resolution of defects in the surface texture according to the size of the steel ball, it is possible to use a convex lens 57 corresponding to the size of the steel ball and change the magnification of the optical system. To rotate the steel balls in a skewed manner, for example, as disclosed in Japanese Patent Publication No. 42-17608, a control roller manufactured according to the size of the steel balls or the skew is used, or The skew mechanism as disclosed in Japanese Patent Laid-Open No. 56-58643 must be provided. Therefore, the parts must be replaced one by one according to the change of the steel ball size. Similar to the above, there is a problem that it takes time and effort to set the device. Further, contact between these parts and the steel balls 54 may cause wear or damage of the parts, which may cause skew rotation irregularity. Therefore, in order to sufficiently guarantee the inspection result of the total surface area of the steel balls 54. Requires careful and artificial management. Furthermore, for example, a control roller and a skew mechanism capable of skew-rotating a steel ball 54 having a small diameter of about 1 mm are practically extremely difficult to manufacture in terms of production technology. That is, in the second conventional example, there are various problems as described above in terms of replacement and maintenance of the rotation control mechanism and manufacturing.

The present invention has been made in view of these problems, and the properties of the entire surface of the inspected sphere can be obtained without changing the optical system according to the steel ball size of the inspected sphere. It is an object of the present invention to provide a sphere surface inspection device capable of inspecting a sphere easily and with high accuracy.

[0011]

In order to achieve the above object, the present invention provides a light source for illuminating the surface of a sphere to be inspected and a light amount detecting means for detecting the amount of light reflected from the surface of the sphere to be inspected. A polarizing means disposed on the optical path formed between the light source and the light quantity detecting means, and a surface for determining the surface texture of the inspected sphere based on the detection value detected by the light quantity detecting means. In a spherical surface inspection apparatus including a property determining means, at least a part of an inner surface of a curved surface obtained by the polarizing means rotating a major axis of an ellipse having a first focus and a second focus is a mirror surface. And an elliptic mirror, and at least one end face of the rotating shaft is formed in a slanted form, a flat mirror is provided on the one end face, and the axis of the rotating shaft is disposed at a predetermined position on the major axis. Movable rotating mirror and from the light source A light collecting means for collecting the emitted light on the plane mirror and guiding the reflected light from the plane mirror to the light quantity detecting means, and disposing the center of the inspected sphere on the second focus. It has a sphere driving means for rotating the sphere, and the entire surface area of the sphere to be inspected is scanned by the light emitted from the light source through the polarizing means.

[0012]

According to the above construction, the light emitted from the light source is condensed and reflected by the plane mirror of the rotating or swinging rotating mirror,
The light enters the sphere to be inspected on the second focal point through the elliptical mirror. Then, the light incident on the inspected sphere travels backward and is detected by the light amount detecting means as reflected light, so that the rotating mirror rotates a plurality of times or a plurality of times while the inspected sphere makes one rotation on the second focus. The property of the entire surface of the sphere to be inspected can be inspected by oscillating or by rotating the sphere to be inspected a plurality of times while the rotary mirror rotates by a predetermined rotation angle.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an overall configuration diagram schematically showing an embodiment (first embodiment) of a sphere surface inspection apparatus according to the present invention. The sphere surface inspection apparatus is, for example, a single wavelength of 780 nm. A laser diode (light source) 1 that emits a laser beam, a light source driving unit 2 that emits a drive signal to the laser diode 1, and a photodetector 3 such as a photodiode that detects the amount of light obtained through a predetermined optical path described later. (A light quantity detecting means), a slit 5 having a predetermined window portion 4 arranged behind the light detecting element 3, and the laser diode 1
Polarizing means 7 that guides the outgoing light flux emitted from the above to the inspected sphere 6 arranged at a predetermined position and guides the reflected light from the inspected sphere 6 to the photodetection element 3 through the slit 5.
The surface texture determining means 8 for determining the surface texture of the inspected sphere 6 which is a steel ball based on the detection value detected by the light detecting element 3 and the spherical center of the inspected sphere 6 are on the second focus B. A sphere inspection section 9 for supplying the sphere 6 to be inspected to a predetermined position to rotate the sphere 6 to be inspected and for selecting the sphere 6 to be inspected according to the surface texture of the sphere 6. There is.

The polarization means 7 is, specifically, a part of a curved surface obtained by rotating the major axis 11 of an ellipse 10 having a first focal point A and a second focal point B, that is, a predetermined inner surface area 12.
Ellipsoidal mirror 13 having a mirror surface and one end surface 15 of the rotating shaft 14.
Is formed in an inclined shape and the flat mirror 16 is fixed to the one end surface 15 (including surface treatment such as vapor deposition), and the intersection of the flat mirror 16 and the axis 17 is at a predetermined position on the long axis 11, that is, the first A rotary mirror 18 which is arranged so as to be at the position of the focal point A and is rotatable or swingable in the direction of arrow C via a drive motor (not shown), and a light beam emitted from the laser diode 1 is condensed on the plane mirror 16. Further, it is provided with a condensing means 19 for guiding the reflected luminous flux from the plane mirror 16 to the photodetecting element 3, and the condensing means 19 further transforms the luminous flux emitted from the laser diode 1 into a parallel luminous flux. Then, the parallel light flux transmitted through the first lens 20 is transmitted and the plane mirror 1
The beam splitter 21 that is a half mirror that reflects the radiant flux from 6 and supplies it to the photodetecting element 3 through the slit 5, and the radiant flux that has passed through the beam splitter 21 is collected at the first focal point A on the plane mirror 16. A second lens 22 is provided which supplies a reflected light flux which is emitted from the plane mirror 16 and travels backward from the plane mirror 16 to the beam splitter 21. In addition, the first
As the second lenses 20 and 22, theoretically inexpensive convex lenses may be used, but it is preferable to use compound lenses capable of correcting various aberrations.

The inner surface predetermined area 12 in which the mirror surface of the elliptic mirror 13 is formed is specifically shown in FIG.
The width region L is larger than the width region 1 into which the radiation beam reflected from 6 can enter. That is, the predetermined area 12 of the inner surface is an area having an angle θ of at least 180 °, preferably 200 ° so that the radiant flux reflected from the elliptical mirror 13 scans the entire surface area of the upper surface of the inspected sphere 6. A mirror surface is formed.

Further, the sphere inspection section 9 is movable in the direction of arrow D, specifically as shown in FIG. 3, and the sphere 6 to be inspected.
A stopper 23 for appropriately stopping the sphere 6, a guide member 25 for guiding the sphere 6 to be inspected to the drive roller 24 (rotating in the direction of arrow F), and a sphere 6 to be inspected by holding the sphere 6 to be inspected on the drive roller 24. Sphere driving means 26 for rotating the rotating body, and sorting means 28 for sorting the good product and the defective product by rotating the hinge 27 in the arrow E direction based on the determination result of the surface shape determining means 8.
It has and. That is, in the sphere inspection unit 9, the sphere 6 to be inspected is conveyed to the drive roller 24 through the guide member 25 by the upward movement of the stopper 23, and the sphere 6 is rotated by the sphere drive means 26. The surface shape determination means 8 determines the surface shape of the entire surface.
Then, based on the determination result of the surface shape determination means 8, the hinge 27 is appropriately moved in the direction of arrow E, and the sphere whose inspection has been completed is stored in either the good product storage unit 29 or the defective product storage unit 30.

As shown in FIGS. 4 and 5, the sphere driving means 26 is provided with a V-shaped groove 31 for loosely fitting and holding the sphere 6 to be inspected and via a drive motor (not shown). The drive roller 24 rotating in the direction of arrow F, a round bar-shaped support roller 33 whose both ends are rotatably supported by a pair of left and right bearing portions 32a and 32b, and the bearing portion 32.
arm part 34 for accommodating a and 32b, and the arm part 34
And a pivot 35 provided on the base end side of the.

In the sphere driving means 26, when the sphere 6 to be inspected is inspected, as shown in FIG.
Is rotated in the direction of the arrow F, the inspected sphere 6 is driven by the drive roller 2
The support roller 3 rotates in the direction of arrow G due to the frictional force with the support roller 3.
Reference numeral 3 supports the inspected sphere 6 while rotating in the direction of arrow H. This allows the inspected sphere 6 to rotate while disposing its spherical center on the second focal point B, so that all the light from the elliptical mirror 13 is incident perpendicularly on the inspecting sphere 6. The surface area of the inspected sphere 6 is inspected by scanning the entire surface area of the inspected sphere 6. Then, when the inspection of the surface texture of the inspected sphere 6 is completed, the pivot 35 moves to the arrow K.
The spherical body 6 to be inspected is separated from the driving roller 24 and sent to the selecting means 28. The drive roller 24
Is movable on a straight line (direction of arrow L) connecting the position (first focus A) where the ball center of the inspected sphere 6 should be held and the rotation center of the drive roller 24, and various steel ball sizes are different. It is possible to inspect the surface texture of the inspected sphere 6. Further, in the sphere driving means 26, the pivot 35 supports the holding and separation of the sphere 6 to be inspected from the driving roller 24. Instead of the pivot 35,
It goes without saying that the movement of the spherical body 6 to be inspected and the detachment from the driving roller 24 may be supported by a moving stage or another method.

In the spherical surface device thus constructed, as shown in FIG. 1, the emitted light flux emitted from the laser diode 1 whose light emission amount is controlled by the light source driving means 2 is emitted by the first lens 20. It is converted into a parallel light flux, passes through the beam splitter 21, and is focused on the first focus A of the ellipse 10 by the second lens 22. Since the rotary mirror 16 is arranged so that the first focus A and the axis 17 of the plane mirror 16 coincide with each other, the light flux emitted from the laser diode 1 is condensed on the axis 17 of the plane mirror 16. The radiated light flux that is incident on the plane mirror 16 is reflected and travels toward the elliptic mirror 13, and is further reflected by the elliptic mirror 13 to form a second beam.
The light enters the sphere 6 to be inspected, which is disposed on the focal point B, in a perpendicular direction from all directions.

The light beam thus vertically incident on the sphere 6 to be inspected is reflected by the sphere 6 to be inspected, and the portion having no scratches or stains on the surface goes backward in the light incident path and again the elliptical mirror. It returns to the second lens 22 via 13 and the plane mirror 16. Then, the reflected light flux returning to the second lens 22 is bent at a right angle by the beam splitter 21, and only the light that has passed through the window portion 4 of the slit 5 enters the photodetection element 3 and the photodetection element 3 Photoelectric conversion is performed, and the presence or absence of the defect is determined by the surface shape determination unit 8, and the non-defective or defective product of the inspected sphere 6 is selected by the selection unit 28 of the sphere inspection unit 9. That is, as shown in FIG. 7, of the reflected light flux from the beam splitter 21, only the light that has passed through the window portion 4 of the slit 5 (indicated by the hatched portion in the figure) enters the photodetection element 3 and Photoelectric conversion is performed by the photodetector 3. When defects such as scratches and stains are present on the surface of the inspected sphere 6, the reflected light from those parts is scattered, and a bright-dark pattern corresponding to these defects is formed on the surface of the window 4. Since it is formed, the amount of light passing through the slit 5 changes. Then, these light amounts are photoelectrically converted by the photodetector 3, and the surface shape determination means 8 determines that the surface property of the inspected sphere 6 is abnormal.

In the first embodiment, however, the elliptic mirror 1
In order that the light from the plane mirror 16 may enter the predetermined area 12 on the inner surface of the rotary mirror 3, the rotary mirror 18 has a positive / negative 45 with reference to the position shown in FIG.
The surface texture of the sphere 6 to be inspected is inspected in the section which is rotating in the range of °.

FIG. 8 is a diagram showing how the incident light flux and the reflected light flux change depending on the rotation angle of the rotary mirror 18.

When the rotation angle of the rotary mirror 18 is 0 °, that is, when light is incident at the position shown in FIG. 1, the light flux corresponds to the substantially central portion of the elliptical mirror 13 as shown in FIG. 8A. At the same time, the light flux is incident on the spherical body 6 to be inspected from above, and the incident light flux travels backward in the incident optical path. Further, as shown in FIG. 8B, when the rotating mirror 18 is rotated by 45 ° in the direction of arrow I, that is, the rotating mirror 18
When the rotation angle is 45 °, the light beam is incident on the position corresponding to the upper part of the elliptic mirror 13 in the figure, the light beam is incident on the inspected sphere 6 from the horizontal direction, and the incident light beam is Reverse the incident light path. Further, as shown in FIG. 8C, when the rotating mirror 18 is rotated by 45 ° in the direction of the arrow J, that is, when the rotating angle of the rotating mirror 18 is −45 °, the luminous flux is a diagram of the elliptical mirror 13. The light beam is incident on the position corresponding to the middle and lower parts and is incident on the inspected sphere 6 from the horizontal direction, and the incident light beam travels backward in the incident optical path. That is, since the inspected sphere 6 is arranged so that the center of the inspected sphere 6 coincides with the second focal point B, the light beam is always incident on the surface of the inspected sphere 6 from the vertical direction. . In addition, the rotary mirror 18 has a positive / negative 4 with reference to the vertical position in FIG.
When rotating by 5 °, that is, while the rotating mirror 18 swings between −45 ° and + 45 °, or when the rotating mirror 18 rotates, the rotating angle rotates in the range of −45 ° to + 45 °. During this period, the semicircular portion exposed on the upper surface side of the inspected sphere 6, that is, 180 °, is inspected through the slit 3. Further, since the inspected sphere 6 is supported by the support roller 33 and is rotated by the frictional force between the inspected sphere 6 and the drive roller 24, the rotating mirror 18 is swung or rotated a plurality of times while the inspected sphere 6 makes one revolution. Alternatively, the rotary mirror 18 has a predetermined angle,
That is, by rotating the inspected sphere 6 a plurality of times while rotating the section from −45 ° to + 45 °, the entire surface of the inspected sphere 6 is scanned by the light flux from the laser diode 1, and therefore the inspected sphere 6 is scanned. The surface texture can be inspected over the entire surface of the inspection sphere 6.

When the rotating mirror 18 is rotated and inspected in the first embodiment, there is a section in which the inspection cannot be performed depending on the rotational position of the rotating mirror 18, as described above. Judgment means for judging only the section in which the light flux reflected from the inspected sphere 6 is incident on the photodetecting element 3 (for example, sensors such as an encoder for detecting the rotation angle of the rotating mirror 18 and outputs based on these sensors). Output means such as a gate circuit for outputting a signal only in a section of a predetermined rotation angle), stable rotation can be easily obtained, and the inspection speed can be increased easily. On the other hand, the rotating mirror 1
When the inspection is performed by swinging 8, the swing range in which the reflected light flux from the inspected sphere 6 is incident can be selected, so that the rotation section is wasted when rotating the rotary mirror 18. Although there is no need to provide the determining means described above, it becomes difficult to obtain stable high-speed rotation as compared with the case where the rotary mirror 18 is rotated. Therefore, it is preferable to appropriately select either the swing or the rotation according to the application.

When the steel ball size of the inspected sphere 6 changes, it is desirable to proportionally change the lower limit of the size of the defect to be detected according to the size of the steel ball. According to the first embodiment, the spherical center of the inspected sphere 6 is an ellipse 1
Since the sphere 6 to be inspected is arranged so as to coincide with the second focal point B of 0, the incident light flux is focused on the spherical center of the sphere 6 to be inspected, and therefore the size of the steel ball of the sphere 6 to be inspected. Regardless of this, the solid angle is always constant, and it is possible to avoid troublesome parts replacement and the like for the inspected spheres 6 having various steel ball sizes.

FIG. 9 shows a second embodiment of the spherical surface inspection apparatus, which is on the optical path through which the light beam from the laser diode 1 travels and on the major axis 11 of the ellipse 10. The fixed plane mirror 36 is provided at a predetermined angle with respect to the major axis 11. That is, in the second embodiment, the condensing means 37 is provided with the fixed plane mirror 36 in addition to the above-mentioned first and second lenses 20, 22 and the beam splitter 21. Further, in the rotating mirror 38, the plane mirror 16 is fixed to the inclined one end face 39 so that the reflected light flux can enter the elliptic mirror 13 after the light flux reflected from the fixed plane mirror 36 enters.

In the spherical surface inspecting device thus constructed, the emitted light flux emitted from the laser diode 1 is divided into the first lens 20, the beam splitter 21 and the second lens 20.
Is incident on the fixed plane mirror 36 through the lens 22 of No. 1, and the incident light beam is then bent by the fixed plane mirror 36 toward the rotating mirror 38 and condensed at the first focal point A on the plane mirror 16, and then the first focus A.
Similar to the embodiment described above, the spherical center is incident on the inspected spherical body 6 arranged on the second focal point B from the vertical direction. Then, the reflected light flux from the inspected sphere 6 travels backward in the incident optical path and the reflected light flux is input to the photodetecting element 3, and the surface shape of the inspected sphere 6 is inspected as in the first embodiment. .

In the second embodiment, the surface texture of the sphere 6 to be inspected is inspected within a range of positive and negative 90 ° with reference to the position shown in FIG. That is, -90 ° with reference to the position shown in FIG.
The surface texture of the inspected sphere 6 is inspected in the rotation section from + 90 ° to + 90 °. That is, in the first embodiment, 90 degrees of the rotation of the rotary mirror 18 from −45 ° to + 45 °.
°, that is, 1/4 of the rotation of the rotating mirror 18 is used for the inspection, whereas in the second embodiment, 180 ° of -90 ° to + 90 ° of the rotating of the rotating mirror 38, That is, since half of the rotation of the rotary mirror 38 is used for the inspection, the inspection time can be shortened and the efficiency can be improved.

FIG. 10 shows a third embodiment of the spherical surface inspection apparatus, which is obtained by omitting the first lens 20 in the first and second embodiments. is there. By omitting the first lens 20 in this way, it is also preferable to simplify the device.

FIG. 11 shows a fourth embodiment of the spherical surface inspection apparatus, in which a polarization beam splitter 40 is used in place of the beam splitter 21 used in the first embodiment and the like, and a polarization beam splitter 40 and A quarter wave plate 41 is interposed between the second lens 22 and the second lens 22. That is, 1 /
A straight line that crosses the direction of linearly polarized light of a predetermined single wavelength (780 nm) emitted from the laser diode 1 by passing through the four-wave plate 41 back and forth and displacing the phase by ½ wavelength (180 ° in terms of phase). Since it becomes polarized light and is reflected by the polarization beam splitter 40 in the direction of the photodiode 3, the power of the laser light can be effectively utilized, and therefore the signal-to-noise ratio (S / N ratio) is improved.

Further, as a further modification of the present invention, FIG.
It goes without saying that the arrangement positions of the laser diode 1 and the first lens 20 and the arrangement positions of the slit 5 and the photodetecting element 3 may be interchanged as in the fourth embodiment shown in FIG. Absent.

Further, it goes without saying that instead of providing the plane mirror 16 in each of the above-mentioned embodiments, the one end surfaces 15, 39 of the rotary shafts 14, 38 may be mirror-finished by polishing or the like.

[0034]

As described above in detail, according to the spherical surface inspection apparatus of the present invention, the light emitted from the light source is condensed and reflected by the plane mirror of the rotating mirror, passes through the elliptical mirror, and is focused on the second focus. The light incident on the sphere to be inspected, and further, the light incident on the sphere to be inspected travels backward and is detected by the light amount detecting means as reflected light, so that the solid angle of the incident light on the sphere to be inspected becomes constant, and Even if the steel ball size of the sphere changes, there is no need to change and adjust the optical system by replacing parts, etc., and the preparation for measurement does not take time.

Further, since the light scans the entire surface of the sphere to be inspected by rotating or oscillating the rotating mirror, it is not necessary to rotate the sphere to be inspected in a skewed manner, and therefore it is also necessary to use a control roller as in the prior art. Also, there is no need to use a skew mechanism that may cause irregular rotation speed,
It is possible to accurately inspect a sphere having a small diameter, and to obtain an inexpensive sphere surface inspection device that is easy to operate and maintain.

[Brief description of drawings]

FIG. 1 is a conceptual diagram schematically showing an embodiment of a spherical surface inspection device according to the present invention.

FIG. 2 is a perspective view for explaining a predetermined area on the inner surface forming an elliptical mirror.

FIG. 3 is a detailed configuration diagram of a sphere inspection unit.

FIG. 4 is a front view showing details of a spherical body driving means.

FIG. 5 is a plan view showing details of a spherical body driving means.

FIG. 6 is a perspective view of a spherical body driving means.

FIG. 7 is a diagram showing a relationship between a slit and a light detection element.

FIG. 8 is a diagram showing how incident light flux and reflected light flux are changed by rotation of a rotating mirror.

FIG. 9 is a conceptual diagram schematically showing a second embodiment of the spherical surface inspection device according to the present invention.

FIG. 10 is a schematic diagram of a main part schematically showing a third embodiment of the spherical surface inspection apparatus according to the present invention.

FIG. 11 is a schematic diagram of a main part schematically showing a fourth embodiment of the spherical surface inspection apparatus according to the present invention.

FIG. 12 is a schematic diagram of a main part schematically showing a fifth embodiment of the spherical surface inspection apparatus according to the present invention.

FIG. 13 is a conceptual diagram of a main part schematically showing a first conventional example of a spherical surface inspection device.

14 is a view on arrow X in FIG. 13. FIG.

FIG. 15 is a schematic diagram of a main part schematically showing a second conventional example of the spherical surface inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 laser diode (light source) 3 light detecting element (light amount detecting means) 6 inspected sphere 7 polarizing means 8 surface texture determining means 12 inner surface predetermined area 13 elliptical mirror 14 rotation axis 15 one end surface 16 plane mirror 17 axis core 18 rotating mirror 19 assembly Optical means 26 Sphere driving means

Claims (1)

[Claims] 1. A light source for irradiating the surface of an inspected sphere, a light amount detecting means for detecting an amount of reflected light reflected from the surface of the inspected sphere, and a light source formed between the light source and the light amount detecting means. A spherical surface inspecting device comprising a polarizing means arranged on the optical path, and a surface texture determining means for determining the surface texture of the inspected sphere based on the detection value detected by the light quantity detecting means, The means has an elliptic mirror in which at least a part of an inner surface of a curved surface obtained by rotating the major axis of an ellipse having a first focal point and a second focal point is a mirror surface, and at least one end surface of the rotational axis is inclined. And a rotatable mirror having a flat mirror provided on one end face thereof and an axis of the rotary shaft disposed at a predetermined position on the long axis, and a light emitted from the light source. Focus on the plane mirror and A sphere driving means for arranging the spherical center of the sphere to be inspected on the second focus and rotating the sphere to be inspected. An apparatus for inspecting a surface of a sphere, wherein the entire surface area of the sphere is scanned by the light emitted from the light source through the polarization means.