JP4695793B2 - Optical observation device for light-reflective spherical surface - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical observation apparatus suitable for observation of a light-reflective spherical surface, particularly a specular reflective spherical surface of a microsphere.
[0002]
[Prior art]
Even when trying to optically and visually observe the state of the specular reflective spherical surface of a light reflecting spherical surface, particularly a microsphere such as a solder ball, by ordinary indoor lighting, the light from above and from the four sides is caused by the minimal convex mirror effect of the spherical surface. It was difficult to detect abnormalities such as flaws and minute irregularities due to reflection with high brightness in the direction of the viewing line of sight, and only spot or minute ring-like brightness was seen or halation occurred.
[0003]
For this reason, an upper light source having a ring shape or a conical slope shape is used so that light from the upper side and the four sides is incident on the observation-side hemisphere relatively uniformly, or this is used in combination with light transmitted illumination from the lower side. Attempts have been made to make observations such as making the circumference of the spheres stand out. However, even in this method, in the case of a light-reflective microsphere, such as a solder ball of about 0.5 to 1.0 mmφ, all parts have appropriate brightness when viewed from above. It was difficult to observe clearly without producing bright spots or shadows.
[0004]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide an optical observation device for clearly observing or photographing a light-reflecting spherical surface.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides: a) a light-transmitting plate that is arranged substantially horizontally; and at least one positioning spot for receiving the lower partial spherical surface of the test ball on the upper surface. A placed test ball fixing plate,
b) The lower end is kept in contact with or close to the upper surface of the test ball fixing plate, and the outer diameter is about 1 mm larger than the test ball diameter to about four times the test ball diameter. A translucent tube to be placed coaxially with the vertical axis that passes through one of the test balls,
c) Functions as an inward surface light source along the conical slope of a hollow truncated cone with the semi-transparent cylinder coaxially surrounded and with the truncated head facing upward, and passes through the semi-transparent cylinder to the upper portion of the subject ball Shadowless illumination structure for shadowless illumination of the hemisphere,
d) having a diameter or side length larger than the outer diameter of the translucent tube, which is arranged coaxially with the vertical axis at a level slightly spaced from the lower surface of the test ball fixing plate. By having a transmission illumination structure consisting of an upward facing surface light source,
e) The optical surface of the light-reflecting sphere, wherein the upper hemisphere of the test sphere is magnified or observed from above through an opening formed in the cone head of the shadowless irradiation structure. An observation apparatus was configured.
[0006]
In the above, “semi-transparent” in the “semi-transparent tube” means light scattering transmission by a so-called “semi-transparent medium”, and is 1 / of “semi-transparent film” and “semi-transparent mirror (half mirror)”. 2 transmission: It does not mean 1/2 transmission in 1/2 reflection. Hereinafter, when the term “semi-transparent” is used for other elements, the term “scattering transmission” is also used. Further, the term “transmission illumination” is used to mean “illumination for seeing through a watermark” of the subject sphere.
[0007]
In the present invention, the inward surface light source along the conical slope is formed by forming a conical slope of the truncated cone from a semi-transparent plate, and arranging a large number of light emitting elements on the outer side of the semi-transparent plate, The light is emitted from the light emitting elements through a semitransparent plate.
[0008]
In the present invention, the second form of the inwardly facing surface light source along the cone slope is formed by forming the cone slope of the truncated cone with a plastic plate and arranging a large number of light emitting elements on the side surface of the plastic plate in the cone. Thus, the surface light source has a surface crossing these light emitting element arrays.
[0009]
The frustoconical pyramid having a shadowless irradiation structure in these forms is typically a truncated cone, but may be a truncated pyramid according to design requirements. Note that the term “inward surface light source along the conical slope of the truncated cone” refers to a wall surface that is curved in a dome shape between the upper and lower edges of the conical slope, in addition to the case where the conical and pyramidal slope itself is the light source. It also includes light emission from.
[0010]
The height of the translucent cylinder, which is a core element of the present invention, may be at a level such that incident light from the upper end of the cylinder does not directly hit the test sphere positioned at the lower end of the cylinder. The upper end of the cylinder protrudes upwardly through the fringe opening edge of the truncated cone in the shadowless irradiation structure, and the shadowless irradiation structure protects the protruding portion. A cylinder protection block having a top surface having a height equal to or higher than the tip of the transparent cylinder, and a protective hole that opens on the top surface and faces the opening edge so as to surround the protruding portion of the translucent cylinder It is provided.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an apparatus configuration diagram in which a main part is drawn in cross section to show a typical embodiment of the invention. 1 is a main body of the optical observation apparatus of the present invention, 2 is a light source element (herein) Power supply for illuminating the LED), 3 is a CCD camera for observing and photographing the subject sphere from above the apparatus body 1, 4 is for monitoring and printing and recording image signals from the CCD camera 3. It is a monitor to do.
[0012]
Further, in FIG. 1, the apparatus main body 1 includes a test ball fixing plate 6 made of a light transmissive plate for supporting a small test ball 5 having a plurality of light-reflecting spherical surfaces, and the fixing plate 6. The semi-transparent cylinder 7 is made upright on the fixed plate 6 coaxially with the vertical axis passing through the test ball 5a located at the measurement spot, and is substantially supported by the fixed plate 6 or slightly spaced. The shadowless irradiation structure 8 for irradiating the upper hemisphere of the test ball 5a through the semi-transparent tube 7 (particularly, its wall) and the test ball fixing plate 6 are substantially supported. Or a transmission illumination structure 9 arranged so as to be coaxial with the vertical axis at a slight interval.
[0013]
The test ball fixing plate 6 that is light-transmitting, that is, transparent or translucent, is composed of a light-transmitting plate body arranged substantially horizontally on the transmission illumination structure 9 and receives the lower partial spherical surface of the test ball on the upper surface. For this purpose, at least one positioning spot made of a partially spherical depression is provided. As can be inferred from the examples described later, the translucent cylinder 7 has an outer diameter of about 1 mm to about 4 mm of the same spherical diameter, and its lower end is in contact with the upper surface of the test ball fixing plate 6. Or upright at close levels.
[0014]
The shadowless irradiation structure 8 includes a hollow truncated cone having a conical slope 10 made of a semitransparent plate coaxially surrounding the semitransparent cylinder 7, and the lower end of the semitransparent cylinder 7 using the conical slope 10 as an inward surface light source. In order to irradiate the central part (the upper hemispherical surface of the test sphere), the head portion thereof is arranged upward, and a light source element array such as an LED 11 is provided on the outer side of the conical slope 10. is there. Thus, the shadowless irradiation structure 8 irradiates the scattered transmitted light from the conical inclined surface (inwardly facing light source) 10 that originates from the light source element array, and further passes through the semitransparent cylinder 7 to the upper hemisphere of the subject sphere 5a. Can be incident in the form.
[0015]
The height of the translucent cylinder 7 which is a core element of the present invention may be at a level such that incident light from the upper end of the cylinder does not directly hit the test sphere positioned at the lower end of the cylinder, as shown in FIG. In addition, typically, the upper end of the cylinder protrudes upward through the truncated cone opening edge 10a of the truncated cone in the shadowless irradiation structure 8, while the shadowless irradiation structure 8 protects this protruding portion. Further, a top surface 12a at the same level as the tip of the semitransparent tube 7 and a protective hole 12b that opens to the top surface 12a and faces the opening edge 10a so as to surround the protruding portion of the semitransparent tube 7 are provided. The cylinder protection block 12 is provided.
[0016]
The lower part of the cylinder protection block 12 has a large-angle conical surface 13 whose outer periphery facing the outside of the conical slope 10 is flat, and an LED is formed on the inner surface of the suspended outer peripheral wall (the lower end of the peripheral surface of the block 12). The support base 11a is supported. Further, the outer edge of the outer peripheral wall 12c of the block 12 is fitted to the outer periphery of the outer flange 10b (FIG. 2) of the conical slope 10. FIG. 2 is a view of the coaxial arrangement relationship of the translucent cylinder 7, the conical slope 10, and the hanging outer peripheral wall 12c of the cylinder protection block 12 as viewed from below along the line AA in FIG. The explanation will be well understood.
[0017]
FIG. 3 is a plan view of the transmitted illumination structure 9 which is the lowermost structure of the apparatus main body 1 as viewed from above. Here, 9a is a square petri dish-like basic frame, for example, having an LED mounting frame 14 inside the four side walls, the upper surface of which is entirely covered by a plastic translucent cover 15, and further this semi-transparent cover. A light blocking frame 17 is installed around the upper surface of the transparent cover 15 in such a range that the tip of the LED 16 is hidden, and the translucent cover 15 exposed from the opening of the frame 17 forms an upward surface light source. Yes.
[0018]
【Example】
FIGS. 4-8 has shown the experimental result for determining the design of the optical observation apparatus in the said embodiment. The equipment used in the experiment is the shadowless illumination structure 8 constituting the conical surface light source, the shadowless ring illuminator (KKR-50 type) manufactured and sold by the applicant company, the conical flange surface and the test ball fixing plate. Used at zero distance (adjacent). The outline of the standard of KKR-50 is: emission color: red, angle of irradiation cone surface with respect to horizontal: 40 °, irradiation area: 30 mmφ, number of LEDs: 54, power consumption 2.2 W. As the transmissive illumination structure 9 constituting the upward surface light source, an edge light type transmissive illuminator (KE-100LE type) manufactured and sold by the applicant company was used. The outline of the standard of KE-100LE is emission color: red, emission area: 80 × 100 mm ² , number of LEDs: 84, power consumption 3.4 W.
[0019]
The test sphere is a solder ball having a sphere diameter of 0.76 mmφ, which is fixed (half-immersed) on a transparent acrylic resin plate having a thickness of about 2 mm, and this resin plate is placed on the edge light type transmission illuminator. The solder ball is placed so as to coincide with the vertical center axis, and the shadowless ring illuminator is arranged as described above, and the upper hemisphere portion of the solder ball is surrounded coaxially. The experimental method and results will be described below.
[0020]
Experiment 1: When there is no shadow irradiation structure (shadowless ring illumination) on the upper hemisphere Fig. 4 shows a case where the subject sphere is imaged by CCD only with illumination from the bottom (edge light type transmitted illumination) A is a schematic drawing of the photographed image, A is not using the translucent cylinder 7 (FIGS. 1 and 2), and B is a translucent plastic straw having an inner diameter of 4 mmφ and a length of 50 mm as the translucent cylinder 7. It is what was used. In all cases, only the peripheral part is slightly bright, and the inside is completely black when there is no cylinder (A), and when there is a cylinder (B), the cylinder has a slight light condensing effect, or the darkness is faint and the spherical surface is faintly observed It is a grade. This shows that lighting from above is essential.
[0021]
Experiment 2: When there is no illumination from the bottom (edge light type transmitted illumination) FIG. 5 shows a photographed image when the subject ball is imaged with a CCD only with a shadowless illumination structure (shadowless ring illumination). A schematic drawing, A does not use the translucent cylinder 7 (FIGS. 1 and 2), and B uses a translucent plastic straw having an outer diameter of 4 mmφ and a length of 50 mm as the translucent cylinder 7. It is. Without the cylinder (A), even in the so-called “shadowless ring illumination”, the ring illumination reflecting ring 18 is formed on the test hemisphere, and the mirror image 19 of the lens portion 3a of the CCD camera is reflected. The peripheral area 20 is dazzling. The regions that can be observed to some extent are only the outer ring and the narrow annular regions 21a and 21b inside and outside the ring illumination reflecting ring 18. In the case with the cylinder (B), the ring illumination reflection and the lens mirror image effect are removed by the translucent cylinder 7, but the peripheral portion is darkened by the absence of illumination from below.
[0022]
Experiment 3: When the length of a semi-transparent tube (made of paper) is changed FIG. 6 includes the above-described shadowless irradiation structure for the upper hemisphere and illumination from below according to the configuration of the present invention, and It is a schematic diagram when experimenting also using a semi-transparent cylinder, A is the length of the semi-transparent cylinder 7 (cylinder having an outer diameter of 2 mmφ made of fine paper) is 10 mm, and B is the length of the same translucent cylinder 7 Is 50 mm. When the cylinder length is 10 mm (A), light enters from the upper end of the cylinder which is at a relatively low level, so that a relatively thin reflecting ring 22 is formed on the hemispherical surface, and the hemispherical apex is constricted with a cylinder. A lens part mirror image 23 is formed. However, scratches 24a and 24b on the spherical surface are slightly observed in a comparatively wide intermediate region between the reflection ring 22 and the vertex mirror image 23. In addition, when the tube length is 50 mm (B), almost no light enters from the upper end of the tube, and the hemisphere is irradiated only by weak scattered light that has passed through the tube. Scratches 24a and 24b are also clearly observed.
[0023]
Experiment 4: When the length of the semi-transparent tube (straw) is changed FIG. 7 shows the same illumination structure according to the configuration of the present invention, and the translucent tube has an outer diameter of 4 mmφ and translucent. It is a schematic diagram at the time of experimenting using a plastic straw, A is the length of the translucent cylinder 7 being 10 mm, and B is 50 mm. When the tube length is 10 mm (A), the level is relatively low, and a relatively large amount of light enters from the upper end of the tube having a wider opening than the paper tube. Therefore, the black spot at the center is large and the surrounding area is blurred, and scratches 24a and 24b Is also unclear. In addition, when the tube length is 50 mm (B), almost no light enters from the upper end of the tube, and the hemisphere is irradiated with the combined light of the scattered light that has passed through the tube and the light from below. Except for this, the entire hemisphere is observed almost uniformly, and the scratches 24a and 24b are also observed almost clearly.
[0024]
Experiment 5: Increasing the height of the shadowless irradiation structure on the upper hemisphere FIG. 8 is a high- quality paper having an outer diameter of 2 mmφ and a length of 50 mm as a translucent cylinder, similarly according to the configuration of the present invention. In a state in which the tube making is made upright on the test ball fixing plate, the distance from the test ball fixing plate to the lower end of the surrounding illumination is not zero (abutment) in the previous experiments, A: 50 mm, and B : It is a schematic diagram at the time of setting to 20 mm. At A (50 mm), this light source power of 2.2 W is too far away (on the contrary, if the light source power is increased, it may cause a problem of spherical reflection), and an illuminance that can be observed on the spherical surface is obtained. Instead, the contour ring 25 only appears light and the others are black. Further, even when the surrounding illumination is brought close to about B (20 mm), the contour ring 25 still appears light, and only the scratches 24a and 24b are observed indistinctly in the dim image of the innermost part.
[0025]
From the above experimental results, for the solder balls having a sphere diameter of 0.76 mm, the lower end flange portion of the conical surface light source is used in the configuration of the experimental use apparatus embodying the present invention and according to the modes of the experiments (1 to 4). When the outer diameter of the semitransparent tube 7 is 2 mm, that is, 2.00 / 0.76 = 2,63 times the diameter of the test ball. 4mm, that is, the image is clearer than when the diameter of the test ball is 5.26 times. In any case, when the tube length is 10 mm, there is reflection due to incident light from the upper end of the tube. It is considered that a sufficiently long length (in this case, 50 mm) is required.
[0026]
However, the material of the cylinder is considered to be a brighter image if it is a translucent material having better light transmission than fine paper, like the straw used in Experiment 4. Further, the ball diameter of the solder ball in this experiment was 0.76 mm. However, if the ball diameter is up to about 1.00 mmφ by experimenting with manufacturing tolerances and approximate standards, this 2 mmφ paper It was confirmed that similar measurements could be made with a tube. Furthermore, taking into account that a 4 mmφ straw could be observed relatively clearly, the outer diameter of the translucent tube is a value from about 1 mm larger than the test ball diameter to about four times the test ball diameter. It is concluded that it is necessary.
[0027]
In the typical example of the device of the present invention, the height of the shadowless irradiation structure to the upper hemisphere (the lower end level of the conical slope light source with respect to the test ball fixing plate) is zero, and the substantial height is given by Experiment 5 Although it has been verified that this is inconvenient, this is a result of using a device (KKR-50: red) having a defined standard and power, and a shadowless irradiation light source with better power and light scattering than this is used. It may be better to use the shadowless illumination light source at a higher position when it is used or when the test spherical surface has a surface state that is easy to observe. FIG. 9 shows an optical observation apparatus 1 ′ in which the position of the shadowless irradiation light source is increased for such a purpose.
[0028]
9, the parts indicated by the same reference numerals as those in FIG. 1 are the same as the instruction parts shown in FIG. The apparatus of this modification has an outer cylinder 26 that is connected to the outer periphery of the structure 8 ′ and supports the lower end flange 10b of the conical slope 10 in the shadowless irradiation structure 8 ′, and the lower end of the outer cylinder 26 is It is configured to be positioned close to the test ball fixing plate 6.
[0029]
FIGS. 10 to 13 show modifications of the optical observation apparatus shown in FIGS. 1 and 9 that can be used as a light source for substantially shadowless irradiation of the upper half of the test ball. A rectangular oblique illuminator in which inclined light sources 27 to 28 are arranged on each pyramidal surface portion of the pyramid, FIG. 11 is a direct ring illuminator in which light source elements 31 such as LEDs having optical axes along respective normal lines are arranged on a conical inclined surface, FIG. 12 shows a coaxial surface-emitting illumination for producing a downward uniform diffused light by applying a light beam emitted from the vertical arrangement of the light source elements 31 to a half mirror 33 disposed at 45 ° through a vertical translucent (light scattering) plate 32. 13 shows a typical example (A) of the low angle direct ring illuminator 34 having a smaller angle with respect to the vertical axis of the conical slope than that of FIG. 11, and a case (B) of the ultimate low angle (0 °), respectively. Show.
[0030]
【The invention's effect】
As described above, according to the present invention, there is provided an optical observation device for clearly observing or photographing a light-reflecting spherical surface, particularly a microspherical surface such as a solder ball. Other examples of objects to be observed include steel balls for ball bearings, bulb balls for ball valves, condensing parts for semiconductor lasers, pearls, ballpoint pen balls, etc. Applicable.
[Brief description of the drawings]
FIG. 1 is an apparatus configuration diagram illustrating a main part in cross section according to a preferred embodiment of the present invention.
FIG. 2 is a bottom view of the shadowless irradiation structure as viewed from below along the line AA in FIG.
FIG. 3 is a plan view of the transmitted illumination structure, which is the lowermost structure of the apparatus main body shown in FIG. 1, viewed from above.
FIG. 4 is a diagram illustrating the effect of the present invention, in which a photographed image (A) of a test hemisphere and a translucent cylinder are used when the translucent cylinder is omitted without using the shadowless irradiation structure of the apparatus main body. It is a figure which shows typically the picked-up image (B) of the to-be-tested hemisphere in the case of having met.
FIG. 5 is a view showing the effect of the present invention, in which a photographed image (A) of a test hemisphere and a translucent cylinder are used when the translucent illumination structure of the apparatus main body is not used and the translucent cylinder is omitted. It is a figure which shows typically the picked-up image (B) of the test hemisphere in a case.
FIG. 6 shows a photographed image (A) of the hemispherical surface to be tested and the same translucent when the entire configuration of the apparatus main body is used and the length of a paper 2 mmφ translucent cylinder is 10 mm in order to verify the effect of the present invention. It is a figure which shows typically the picked-up image (B) of the to-be-tested hemisphere at the time of using the pipe | tube length set to 50 mm.
FIG. 7 shows a photographed image (A) of a hemispherical surface to be examined when the length of a semitransparent cylinder made of plastic straw 4 mmφ is 10 mm, using the entire configuration of the apparatus main body in order to verify the effect of the present invention; It is a figure which shows typically the picked-up image (B) of a to-be-tested hemisphere at the time of using the length of the same semi-transparent cylinder which was 50 mm.
FIG. 8 is a photograph of a hemispherical surface to be examined (A) and 20 mm of the shadowless irradiation structure of the apparatus main body when the height from the test ball fixing plate is 50 mm in order to verify the effect of the present invention; It is a figure which shows typically the picked-up image (B) of the to-be-tested hemisphere at the time of doing.
FIG. 9 is an apparatus configuration diagram illustrating a main part in cross section in a second embodiment of the present invention.
FIG. 10 is a view showing a side cross section (A) and a lower surface (B) in the second embodiment of the shadowless irradiation structure.
FIG. 11 is a side sectional view showing a third embodiment of a shadowless irradiation structure.
FIG. 12 is a view showing a side cross section (A) and a lower surface (B) in a fourth embodiment of a shadowless irradiation structure.
FIG. 13 is a side sectional view showing a typical example (A) of a low-angle direct ring illuminator 34 and a case (B) of a low-angle ultimate (0 °) in the fifth embodiment having a shadowless irradiation structure. It is.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical observation apparatus main body 2 Illumination power supply 3 CCD camera 4 Monitor 5 Small test ball 6 Test ball fixing plate 7 Translucent tube 8 Shadowless irradiation structure 9 Transmission illumination structure 10 Conical slope 11 LED
12 Tube protection block 13 Large angle conical surface

Claims (1)

a) a test ball fixing plate comprising a light-transmitting plate arranged substantially horizontally and having an upper surface provided with at least one positioning spot for receiving the lower partial spherical surface of the test ball;
or b) a lower end in contact with the upper surface of the test sphere fixed plate, or is maintained in close levels, the outer diameter is from about 1mm greater than the test spherical diameter up to about four times the test sphere diameter, observed A translucent tube to be placed coaxially with the vertical axis that passes through one subject ball,
c) A conical slope of a hollow frustoconical cone that coaxially surrounds the translucent cylinder and has a truncated head facing upward is formed of a semitransparent plate, and a large number of light emission is formed on the outer side of the semitransparent plate. By arranging the elements, the semitransparent plate functions as an inward surface light source, and the shadowless irradiation structure for shadowlessly irradiating the upper hemisphere of the test ball through the semitransparent tube,
or d) the upper end is in contact with the lower surface of the test sphere fixed plate, or in a level spaced slightly intervals, is disposed in the vertical and coaxial larger diameter or side length than the outer diameter of the translucent tube A transmission illumination structure comprising an upwardly facing surface light source ,
e) The translucent tube has an upper end that protrudes upward through the truncated cone opening edge of the truncated cone in the shadowless irradiation structure,
f) The shadowless irradiation structure has a top surface that is at the same level or higher as the upper end of the translucent tube, and is open to the top surface so as to surround the projecting portion of the translucent tube in a non-contact manner. By having a cylinder protection block having a protective hole facing the head opening edge ,
g ) A light-reflective spherical optical system characterized in that the upper hemisphere of the test sphere is magnified or observed from above through the truncated cone opening of the truncated cone in the shadowless irradiation structure . Observation device.

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