JP4885489B2 - Dimension measuring device - Google Patents

Description

  The present invention relates to a dimension measuring apparatus, and more particularly, to a dimension measuring apparatus capable of measuring the dimensions of each surface of a test object with high accuracy.

For quality control and other purposes in each industrial field, it may be desired to measure the dimensions of an object to be tested from multiple directions.
5 and 6 are explanatory views showing a conventional example of a method for measuring the dimensions of a test object from multiple directions. As shown in FIG. 5, conventionally, a method has been adopted in which the number of reading devices corresponding to each surface of the object to be examined is set.

  Alternatively, when such a method is not employed, a method of measuring the dimensions of each surface of the object to be inspected with a single reader using a flat mirror as shown in FIG. In addition, the following has been proposed as a technique for simultaneously measuring the shape of each surface of an object.

Japanese Patent Laid-Open No. 5-322526 “Three-dimensional shape measuring apparatus” Japanese Patent Laid-Open No. 5-240607 “Optical Distance Sensor”

  In the prior art shown in FIGS. 5 and 6, when a number of reading devices are installed corresponding to each surface where measurement of the object to be measured is required, a time saving effect can be obtained but the cost is increased. Become. On the other hand, in the example in which the dimensions of each surface are measured by a single reading device, the movement, rotation, and position determination of the reading device or the object to be inspected involve considerable labor and complexity, and time is required.

  Further, the method shown in FIG. 6 cannot simultaneously focus each surface, and does not constitute an apparatus capable of accurate dimension measurement.

  Therefore, the inventors of the present application can solve the above-described problems of the prior art first by simultaneously measuring each surface of the object to be detected with high accuracy and increasing the efficiency of inspection, etc. A patent application was filed for the purpose of providing a cost-effective multi-directional simultaneous observation optical system and an image reading apparatus (Japanese Patent Application No. 2004-54440). The outline of the invention disclosed herein is as follows.

(P1) At least one of one or two or more side surface image acquisition prism systems for obtaining each side image for one or more side surfaces of the test object, or a bottom surface image acquisition prism system for obtaining a bottom image The side image acquisition prism system has an optical path direction changing prism or an optical path direction changing prism function, and the prism system is an object to be inspected. Is provided on the side of the space so as to secure an open space for acquiring the upper surface image and a space for placing the object to be inspected. Multi-directional simultaneous observation, characterized in that the optical path of the emitted light is arranged so as to be directed upward of the object to be examined, parallel to each other and in the same direction, and not to block the optical path Optical system.
(P2) A multiplicity of one or two or more side surface image acquisition prism systems for obtaining each side image for one or more side surfaces of the test object and a bottom surface image acquisition prism system for obtaining a bottom surface image Directional simultaneous observation optical system, each of the side surface image acquisition prism system and the bottom surface image acquisition prism system has an optical path direction changing prism function or an optical path direction changing prism function, and each prism system has In addition, an open space for acquiring the upper surface image is secured in the direction directly above the test object, and a side periphery and a part of the space are positioned below so that a test object placement space is secured. Each prism system is arranged so that the optical path of the light emitted by each of the prism systems is directed upward or parallel to and in the same direction with respect to the object to be measured, and is transmitted by other prism systems. A multi-directional simultaneous observation optical system characterized by being arranged so as not to block a road.
(P3) In each of the side surface image acquisition prism system and the bottom surface image acquisition prism system, the working distance of each surface excluding the upper surface of the object to be measured is above the optical path direction changing prism or the optical path direction changing prism function. The multi-directional simultaneous observation optical system according to (p1) or (p2), characterized in that an optical path length correcting prism or an optical path length correcting prism function for making the same as the working distance of the upper surface is provided .
(P4) The optical path length correcting prism or the optical path length correcting prism function is formed to be exchangeable or optical path length adjustable so that optical path length correction according to the shape and size of the test object is performed. The multi-directional simultaneous observation optical system according to (p3), characterized in that
(P5) For the optical path direction changing prism or the optical path direction changing prism function, a 45 ° mirror prism or a prism having the function is used in the side surface image acquisition prism system, and in the bottom image acquisition prism system, The multi-directional simultaneous observation optics according to (p3) or (p4), wherein a trapezoidal prism, a triangular prism or a prism having any one of these functions is used. system.
(P6) A pentaprism capable of obtaining an erect image or a prism having the function is used as the optical path direction changing prism or the optical path direction changing prism function in the side surface image acquiring prism system. Multi-directional simultaneous observation optical system according to any one of (p3) to (p5).

(P7) Each of the prism systems is provided with an optical path shift prism or an optical path shift prism function for shifting the optical path above the optical path direction changing prism. The multidirectional simultaneous observation optical system according to any one of p6).
(P8) The optical path shift prism or the optical path shift prism function is formed so as to reduce the optical path cross section of the light output from each surface of the object to be measured in order to reduce the incident light area to the lens or the like and increase the resolution. The multi-directional simultaneous observation optical system according to (p7), characterized in that:
(P9) A test object transporting means is provided which can mount two or more test objects and transport them through the test object mounting space, and each prism system has the test system The multi-directional simultaneous observation optical system according to any one of (p3) to (p8), wherein the multi-directional simultaneous observation optical system is arranged such that a path of the object conveying unit is secured.
(P10) The four side surface image acquisition prism systems are provided, and each image information from the six directions of the object to be inspected can be acquired as light, including the upper surface direction where light output is obtained without each prism system. The multidirectional simultaneous observation optical system according to any one of (p3) to (p9).
(P11) In the four systems of side image acquisition prism systems, two sets of two systems facing each other across the object placement space portion are arranged, and each set is orthogonal to each other, Alternatively, the multi-directional simultaneous observation optical system according to (p10), which is arranged at an arbitrary angle.
(P12) The lens further includes a lens provided in a light output direction of the side surface image acquisition prism system and the bottom surface image acquisition prism system or a telecentric lens capable of making the test object side telecentric. The multidirectional simultaneous observation optical system according to any one of (p3) to (p10).
(P13) The lens is characterized by having a depth of field sufficient to adjust the focal plane simultaneously on each surface even if it is a complex test object having a sphere or a super polyhedron in shape. The multidirectional simultaneous observation optical system according to (p12).

(P14) An electronic imaging device including the multi-directional simultaneous observation optical system according to any one of (p11) to (p13) and a CCD, CMOS, or line CCD for photoelectric conversion processing of light obtained through the lens And an image reading apparatus characterized in that it can be used for image analysis including image measurement.
(P15) The multidirectional simultaneous observation optical system according to any one of (p11) to (p13) acquires image information of each surface of the object to be inspected as light, and the light obtained through the lens is obtained as a CCD, An image reading method characterized in that image information that can be electrically processed is obtained by performing photoelectric conversion processing by an electronic image pickup device including a CMOS or a line CCD, and thus can be used for image analysis including image measurement. .
(P16) Each of the side surface image acquisition prism system and the bottom surface image acquisition prism system has an open space above the optical path direction changing prism or the optical path direction changing prism function so that visual observation with the naked eye can be easily performed. The multidirectional simultaneous observation optical system according to (p1) or (p2), wherein the multidirectional simultaneous observation optical system is formed.
(P17) For the optical path direction changing prism or the optical path direction changing prism function, a triangular mirror prism or a prism having the function is used in the side image acquisition prism system, and in the bottom image acquisition prism system, The multidirectional simultaneous observation optical system according to (p16), wherein a trapezoidal prism, a triangular prism, or a prism having a function thereof capable of obtaining a double direction change is used.
(P18) The pentagonal prism capable of obtaining an erect image or a prism having the function is used for the optical path direction changing prism or the optical path direction changing prism function in the side surface image acquiring prism system. , (P16) or (p17).
(P19) The multi-direction according to any one of (p16) to (p18), characterized in that an antireflection prism or its function is provided above the trapezoidal prism or triangular prism or its function. Simultaneous observation optical system.
(P20) A test object transporting means is provided that can mount two or more test objects and transport them via the test object mounting space, and each prism system includes the test object The multi-directional simultaneous observation optical system according to any one of (p16) to (p19), wherein the multi-directional simultaneous observation optical system is arranged such that a path of the object conveying unit is secured.
(P21) Four side image acquisition prism systems are provided, and each image information from the six directions of the test object can be acquired as light, including the upper surface direction where light output can be obtained without each prism system. The multidirectional simultaneous observation optical system according to any one of (p16) to (p20).
(P22) In the four systems of side image acquisition prism systems, two sets of two systems facing each other across the test object placement space are arranged, and each set is orthogonal to each other, Alternatively, the multidirectional simultaneous observation optical system according to (p21), which is arranged at an arbitrary angle.
(P23) Multi-directional simultaneous observation characterized in that two or more multi-directional simultaneous observation optical systems described in (p1) or (p2) are used and multi-directional simultaneous observation of an object to be examined is possible. Optical system complex.

According to the above-described invention, the object to be inspected can be simultaneously observed from each surface with high accuracy, and the efficiency of inspection or the like can be increased. More specifically, for example, the following effects can be obtained.
(I) Regardless of whether the shape of the test object can be grasped in a roughly cubic shape or a rectangular parallelepiped, the in-focus plane can be adjusted simultaneously in all six directions, and an image without so-called vignetting can be provided simultaneously. Therefore, it is possible to accurately perform image analysis such as appearance defect inspection, to shorten the time for inspection and the like, to increase the efficiency of inspection and the like, and to reduce the cost.
(II) Even if the object to be examined is a polyhedron with a top and bottom heptahedron or more, a sphere, or a super polyhedron, increase the number of side image acquisition prism systems and increase the depth of field of the lens of the reader. Thus, it is possible to simultaneously provide an in-focus image on all surfaces and an image without vignetting.
(III) By replacing the 45 ° mirror prism of the side image acquisition prism system with a pentaprism or the triangular mirror prism with a pentagonal prism, an upright image can be provided simultaneously.
(IV) By adding an optical path shift prism function such as an optical path shift prism or an optical path shift plane mirror, the incident light area to the lens is reduced, and the object size captured per image of the image sensor is reduced, resulting in improved resolution. Can be increased.
(V) A multi-directional simultaneous observation of a large number of test objects can be performed continuously by providing a transport path through which the test objects can be moved.
(VI) By using an object-side telecentric lens as the lens of the reading device, the size of each prism can be suppressed and the arrangement thereof can be made closer due to its characteristics, and the overall size can be reduced. Also, image measurement such as dimensional defect inspection can be performed accurately.

  Now, the application of the previous invention is possible in various ways, and observation can be performed efficiently. However, although the above-described invention is a technique that is superior to the related art in terms of dimensional measurement, further improvements aiming at higher accuracy are required.

  Therefore, the problem to be solved by the present invention is to provide a multi-directional simultaneous observation optical system and an image reading apparatus capable of simultaneously measuring each surface of a test object with high accuracy and improving the efficiency of inspection and the like. The object is to provide an apparatus for measuring the size of a test object.

  As a result of studying the above problems, the inventor of the present application has used a prism arrangement method capable of providing a single focal length for an image from each surface, a lens configuration for accurately measuring dimensions, and a test object. The present inventors have found that the above problems can be solved by examining the state of the end face and boundary of the prism for guiding the image from each surface of the object to the lens with high accuracy, and have reached the present invention. That is, the invention claimed in the present application, or at least the disclosed invention, as means for solving the above-described problems is as follows.

(1) having one or more side image acquisition prism systems for obtaining each side image for one or more side surfaces of the object to be examined, and a bottom image acquisition prism system for obtaining a bottom image; A dimension measuring device using a multi-directional simultaneous observation optical system,
The side surface image acquisition prism system and the bottom surface image acquisition prism system (hereinafter also referred to as “each prism system”) have an optical path direction changing prism function or an optical path direction changing prism function, and optical path length correction. Has a function,
Respective prism system is or lateral position of the space as置空between unit test object mounting with the right above direction of the test object is an open space for acquiring the top image is ensured is ensured set vignetting to some lower position,
Each prism system is arranged so that the optical path of the light emitted by each of the prism systems is directed upward of the object to be measured, or parallel to and in the same direction as each other , and is not blocked by the other prism system. And
The lens provided in the optical output direction of each prism system is a telecentric lens, which can be a telecentric a test object side,
A measuring means for measuring a desired dimension of the test object based on the acquired image information ;
Each prism system is integrally formed,
The optical path length correction function is an optical path length provided above the optical path direction changing prism or the optical path direction changing prism function in each prism system in order to match that of each surface with the working distance of the upper surface of the object to be examined. Correction prism,
In each prism system, an AR coating for reducing light reflection is applied to the object side, the lens side, or both surfaces,
In order to reflect the light, either the coating for reflecting the light on the surface of the path turning portion or the material of the refractive index that totally reflects the light is used for the light path turning portion. ,
With such a configuration , the dimension measuring apparatus can measure the side, bottom and top surfaces of the object to be measured simultaneously with high accuracy .
(2) An electronic image pickup device including a CCD, a CMOS, or a line CCD for performing photoelectric conversion processing on the light obtained through the multi-directional simultaneous observation optical system and the lens is provided. (1) The dimension measuring apparatus described in 1.

(3) The dimension measuring apparatus according to (1) or (2), wherein the coating for reflecting light is an aluminum coat.
(4) The dimension measuring apparatus according to (1) or (2), wherein the coating for reflecting light is a dielectric multilayer film.
(5) In order to reflect light at the optical path redirecting portion, the optical path redirecting portion is formed by each means of forming an aluminum coat, forming a dielectric multilayer film, or using a material having a refractive index smaller than that of the incident side. From any one of (1) to (4), any two or more are used together.

  That is, according to the present invention, in order to accurately measure the dimensions of each surface of the object to be measured, first, a telecentric lens capable of making the object side to be telecentric is used as a characteristic configuration of the apparatus. It is.

  In addition, the apparatus of the present invention includes a multi-directional simultaneous observation optical system and an electronic imaging device that performs photoelectric conversion processing on light obtained through a lens, and a configuration that can perform image analysis including image measurement. .

  Furthermore, the apparatus of the present invention includes an apparatus having a configuration in which a special film is formed on a predetermined portion of the prism system in order to guide an image from each surface of the object to be detected with high accuracy.

  AR coating (anti-reflective coating) is a technique usually used for anti-reflection (non-glare) treatment applied to the surface of a CRT display. In the present invention, this is applied to light from an object to be examined to a lens. This is used to improve the accuracy of transmission.

  The dielectric multilayer film is generally used for so-called multilayer film deposition in which a target function based on interference, absorption, reflection, etc. of light is given by coating on a substrate. In the present invention, in order to obtain good reflection of light at the optical path redirecting portion, for example, a thin film is formed by alternately combining a plurality of types of dielectrics having a high refractive index and a low refractive index in a predetermined film thickness. A desired dielectric multilayer film can be formed by appropriately using a multilayer film deposition technique such as coating in multiple layers.

Total reflection means that when light enters a small medium (n ₀ ) from a medium having a large refractive index (n ₁ ), the light is incident at a certain critical angle Θc (sin Θc = (n ₀ / n ₁ )) or more. However, the apparatus of the present invention also includes a prism system configured so as to be totally reflected by reflection at the optical path direction changing unit of the prism system. For example, as a prism member constituting the optical path direction changing portion, a material having a refractive index smaller than that of the incident side prism member is used.

As described above, the multidirectional simultaneous observation optical system according to the dimension measuring apparatus of the present invention is for (a) obtaining one or more side images for obtaining each side image for one or more side surfaces of the object to be examined. Since it is a dimension measuring device using a multi-directional simultaneous observation optical system having at least one of a prism system and (b) a bottom image acquisition prism system for obtaining a bottom image, the following three Pattern is included.
(A) Dimensional measuring apparatus using a multi-directional simultaneous observation optical system having only one or two or more side surface image acquisition prism systems for obtaining each side surface image of one or more side surfaces of a test object .
(B) A dimension measuring apparatus using a multi-directional simultaneous observation optical system having only a bottom surface image acquisition prism system for obtaining a bottom surface image of a test object.
(C) Either one or two or more side image acquisition prism systems for obtaining each side image for one or more side surfaces of the test object, and a bottom image acquisition prism system for obtaining a bottom image A dimension measuring apparatus using a multi-directional simultaneous observation optical system.

  Since the apparatus for measuring a dimension of a test object according to the present invention is configured as described above, according to this, it is possible to simultaneously measure the dimensions of each surface of the test object with high accuracy, and to increase the efficiency of inspection and the like. Can do. In other words, the measurement device including a single telecentric lens can measure the dimensions of each surface of the object to be measured simultaneously and with high accuracy, thereby reducing the measurement time and reducing labor and cost. .

Hereinafter, the present invention will be described in more detail with reference to the drawings.
FIG. 1-1 is a side view showing a general configuration example of a side image acquisition prism system according to the dimension measuring device of the present invention;
1-2 is a side view showing a general configuration example of a prism system for bottom image acquisition according to the dimension measuring apparatus of the present invention, and
FIG. 1C is a side view of a general configuration example of a prism system in which a side image acquisition prism system and a bottom image acquisition prism system are integrated according to the dimension measurement apparatus of the present invention. Also,
FIG. 2 is an explanatory view showing a side view configuration of a main part of the dimension measuring apparatus of the present invention for obtaining image information of the side surface and the top surface of the object to be examined;
FIG. 3 is an explanatory view showing a side view configuration of a main part of the dimension measuring apparatus of the present invention for obtaining image information of the bottom surface and the top surface of the object to be examined; and
FIG. 4 is an explanatory view showing a side view configuration of a main part of the dimension measuring apparatus of the present invention for obtaining image information of the side surface, bottom surface and top surface of the object to be examined. Each configuration shown in FIGS. 2 to 4 uses the prism system configuration shown in FIGS. 1-1 to 1-3.

  As shown in FIG. 2, one example of the dimension measuring apparatus of the present invention is a side image acquisition prism system 3 </ b> A for obtaining each side image for one or more side surfaces of the test object 11, or two or more side images. Using the multi-directional simultaneous observation optical system having the prism systems 3A, 3A ', etc., and the side surface image acquisition prism system 3A or the like is an optical path direction changing prism or an optical path direction changing prism function. (Hereinafter, simply referred to as “optical path direction changing prism” or “optical path direction changing unit”) 30a and an optical path length correcting function. The prism system 3A and the like are directly above the object 11 to be examined. In the direction, an open space for acquiring the upper surface image is secured and a test object placement space is secured at a side position of the space, and the prism system 3A and the like are thereby provided. Optical path 5 of the emitted light Are arranged so as to be directed upward of the object to be inspected 11 or in parallel and in the same direction so as not to obstruct the optical path 5b etc., and the light output direction of the prismatic system 3A for side image acquisition A telecentric lens 41 is provided at the in-focus position on the optical path, and includes measurement means (not shown) for measuring desired dimensions on the side surface and the upper surface of the test object 11 based on the acquired image information. Is the main configuration.

  In FIG. 2, since the device of the present invention is configured as described above, the object 11 side is telecentric, and high-accuracy side images of one or more side surfaces of the object 11 are obtained simultaneously. Based on the image information, desired dimensions on the side surface and the upper surface of the test object 11 are measured by the measuring means.

  In other words, the principal ray, which is a ray that passes through the center of the stop in the optical system, is parallel on the side of the object to be examined 11 of the lens. The telecentric optical system is realized. Therefore, the magnification fluctuation due to the focusing error does not occur, and further, no visual difference with respect to the object to be inspected 11 occurs between the center of the image and the periphery, so that the perspective does not occur over the entire field of view and there is no distortion. Images are acquired, and highly accurate dimensional measurement of each surface is realized.

  In the figure, the light path direction of the light incident on the object 11 from the test object 11 is changed by the optical path direction changing prism of the side image acquisition prism system 3A and the like (upward direction of the test object 11) ( Optical path 5b). The upper surface image of the test object 11 is acquired without passing through the special prism system due to the open space secured in the directly above direction (optical path 5a).

  The optical path length correction function is a function for making the working distance (WD) of each surface of the object 11 to be the same, depending on the refractive index and length of the prism itself constituting the side image acquisition prism system 3A and the like. However, the present invention is not limited to such a method. That is, for example, an optical path length correcting prism (not shown) for making the WD of each surface excluding the upper surface of the object 11 to be the same as the WD of the upper surface above the optical path direction changing prism such as the prism system 3A. It can be set as the structure provided specially.

  Here, the optical path length correction prism can be adjusted by appropriately replacing the optical path length according to the shape and size of the object to be measured, or by other appropriate means. It can also be set as the structure to form.

  As shown in FIG. 3, another example of the dimension measuring apparatus of the present invention uses a multidirectional simultaneous observation optical system having a bottom surface image acquisition prism system 3BC for obtaining a bottom surface image of the object 11 to be examined. The bottom surface image acquisition prism system 3BC has an optical path direction changing prism and an optical path length correction function, like the side surface image acquisition prism system 3A described with reference to FIG. The prism system 3BC is provided with an open space for acquiring a top surface image in a direction directly above the object 11 to be tested, and partially occupies a lower position and a side position. 3BC blocks the optical path by another prism system so that the optical path 5c of the emitted light is directed upward of the object to be inspected 11 or parallel to and in the same direction as the optical path 5a of the top image. Arranged so as not to A telecentric lens 41 is provided at a focal point on the light output direction optical path of the bottom surface image acquisition prism system 3BC, and desired dimensions on the bottom surface and the top surface of the test object 11 based on the acquired image information. The main configuration is that a measuring means (not shown) for measuring the above is provided.

  In FIG. 3, since the apparatus of the present invention is configured as described above, the object 11 side is telecentric, and a highly accurate bottom surface image is obtained for the bottom surface of the object 11 to be detected. Desired dimensions on the bottom and top surfaces of the object 11 are measured by the measuring means.

  In the device of the present invention capable of measuring the dimensions of the bottom surface and the top surface of the object to be measured, a configuration in which a telecentric optical system is realized, a configuration in which the optical path direction is changed, a configuration in which a top image is acquired, an optical path length correction function, and an optical path length correction The configuration of the prism for use is the same as that of the apparatus using the side image acquisition prism system 3A described above.

  As shown in FIG. 4, another example of the dimension measuring apparatus of the present invention includes both the side surface image acquisition prism system 3A shown in FIG. 2 and the bottom image acquisition prism system 3BC shown in FIG. A telecentric lens 41 is provided at a focal point position on the optical path of the light output direction of the side image acquisition prism system 3A and the bottom image acquisition prism system 3BC. The main configuration is provided with measurement means (not shown) for measuring desired dimensions on the side surface, the bottom surface, and the top surface of the test object 11 based on the acquired image information.

  In FIG. 4, since the apparatus of the present invention is configured as described above, the object 11 side is telecentric, and high-accuracy images are obtained on the side surface and bottom surface of the object 11 to be detected. Desired dimensions on the side, bottom and top surfaces of the specimen 11 are measured by the measuring means.

  In the device of the present invention, the configuration in which the telecentric optical system is realized, the configuration in which the optical path direction is changed, the configuration in which the top image is acquired, and the configuration of the optical path length correction function and the optical path length correction prism are described above. It is the same as the case of.

  The above-described dimension measuring apparatus of the present invention is configured to include an electronic image pickup device including a CCD, a CMOS, or a line CCD for performing photoelectric conversion processing on the light obtained through the multi-directional simultaneous observation optical system and the lens. You can also. As a result, the dimension measuring apparatus of the present invention can perform image reading, image measurement, and other image analysis on the screen or image data in combination with appropriate software such as image analysis software, and is highly accurate and efficient. Convenient for accurate dimension measurement.

  In the above description, in the figure, only 3A and 3A ′ are shown as side image acquisition prism systems of the dimension measuring device of the present invention, but the present invention is not limited to this, and the side image acquisition is performed. A larger number of prism systems may be provided. For example, in order to measure the dimensions of the regular hexagonal surface of the test object, four prism systems can be arranged, or a larger number of systems can be arranged depending on the application.

  In the dimension measuring apparatus according to the present invention, in each of the prism systems 3A and the like, an AR coating that reduces light reflection is applied to the surfaces of the object to be tested 32a and 32b, the lens sides 33a and 33b, or both. A characteristic configuration in which an AR coat is formed can be added.

  With such a configuration, reflection of light is reduced on each surface on which the AR coating is applied, and each image can be guided to the lens 41 with high accuracy, thereby further improving the accuracy of dimension measurement.

For the AR coating, SiO ₂ , TiO ₂ , ZnO ₂ , and others conventionally known in this application can be used in an appropriate configuration.

  Further, in the dimension measuring apparatus of the present invention, in each of the prism systems, a coating is formed on the surfaces of the optical path direction changing portions 30a, 30b, 30c, etc. by applying a coating for reflecting light. Can be added.

  With such a configuration, light is favorably reflected at the boundary surface of the optical path direction changing portion 30a and the like with the coating applied, and each image can be guided to the lens 41 with high accuracy. Can be achieved.

As the coating, an aluminum coat or a dielectric multilayer film can be suitably used. The dielectric multilayer film can be formed with an appropriate configuration using, for example, SiO ₂ , TiO ₂ , Al ₂ O ₃ , Ta ₂ O ₅ , and other conventionally used materials.

  As a configuration for obtaining the light reflection effect in the optical path direction changing unit, in order to totally reflect the light, a means that uses a member having a refractive index smaller than that of the incident side as a member constituting the optical path direction changing unit is adopted. Also good. Further, in order to obtain the light reflection effect, two or more of the above methods may be used in combination.

  According to the dimension measuring apparatus for an object to be inspected according to the present invention, each surface of the object to be inspected can be simultaneously measured with high accuracy, and the efficiency of inspection or the like can be increased. It is an invention that is excellent in effect of shortening measurement time, labor and cost, and having high industrial utility value.

It is a side view which shows the general structural example of the prism system for a side image acquisition which concerns on this dimension measuring apparatus. It is a side view which shows the general structural example of the prism system for bottom face image acquisition which concerns on the dimension measuring apparatus of this invention. It is a side view which shows the general structural example of the prism system which integrated the prism system for side surface image acquisition, and the prism system for bottom surface image acquisition based on the dimension measuring apparatus of this invention. It is explanatory drawing which shows the side view structure of the principal part of the dimension measuring apparatus of this invention for obtaining the image information of the side surface and upper surface of a to-be-tested object. It is explanatory drawing which shows the side view structure of the principal part of the dimension measuring apparatus of this invention for obtaining the image information of the bottom face and upper surface of a to-be-tested object. It is explanatory drawing which shows the side view structure of the principal part of the dimension measuring apparatus of this invention for obtaining the image information of the side surface of a to-be-tested object, a bottom face, and an upper surface. It is explanatory drawing which shows the prior art example of the method of measuring the dimension of to-be-tested object from multiple directions. It is explanatory drawing which shows the other conventional example of the method of measuring the dimension of a to-be-tested object from multiple directions.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Test object 3A, 3A '... Side surface image acquisition prism system 3BC ... Bottom surface image acquisition prism system 30a-30c ... Optical path direction change part (optical path direction change prism)
32a, 32b ... Object-side surfaces 33a, 33b of the image acquisition prism system Lens-side surfaces 41 ... Telecentric lenses 5a-5c ... Optical paths 81a-81f ... Test object surfaces 82a-82f ... Flat mirror 840 ... Image reading device

Claims (5)

Multi-direction comprising one or more side image acquisition prism systems for obtaining each side image for one or more side surfaces of the test object, and a bottom image acquisition prism system for obtaining a bottom image A dimension measuring device using a simultaneous observation optical system,
The side surface image acquisition prism system and the bottom surface image acquisition prism system (hereinafter also referred to as “each prism system”) have an optical path direction changing prism function or an optical path direction changing prism function, and optical path length correction. Has a function,
Respective prism system is or lateral position of the space as置空between unit test object mounting with the right above direction of the test object is an open space for acquiring the top image is ensured is ensured set vignetting to some lower position,
Each prism system is arranged so that the optical path of the light emitted by each of the prism systems is directed upward of the object to be measured, or parallel to and in the same direction as each other , and is not blocked by the other prism system. And
The lens provided in the optical output direction of each prism system is a telecentric lens, which can be a telecentric a test object side,
A measuring means for measuring a desired dimension of the test object based on the acquired image information ;
Each prism system is integrally formed,
The optical path length correction function is an optical path length provided above the optical path direction changing prism or the optical path direction changing prism function in each prism system in order to match that of each surface with the working distance of the upper surface of the object to be examined. Correction prism,
In each prism system, an AR coating for reducing light reflection is applied to the object side, the lens side, or both surfaces,
In order to reflect the light, either the coating for reflecting the light on the surface of the path turning portion or the material of the refractive index that totally reflects the light is used for the light path turning portion. ,
With such a configuration , the dimension measuring apparatus can measure the side, bottom and top surfaces of the object to be measured simultaneously with high accuracy . The electronic imaging device including a CCD, a CMOS, or a line CCD for performing photoelectric conversion processing on the light obtained through the multi-directional simultaneous observation optical system and the lens, according to claim 1. Dimension measuring device. Coating for reflecting the light, characterized in that an aluminum coating, sizing device according to claim 1 or 2. Coating for reflecting the light, characterized in that it is a dielectric multilayer film, dimension measuring apparatus according to claim 1 or 2. In order to reflect light at the optical path redirecting portion, the optical path redirecting portion is formed by each means of forming an aluminum coat, forming a dielectric multilayer film, or using a material having a refractive index smaller than that of the incident side. From any one of the above, the dimension measuring device according to any one of claims 1 to 4 , wherein any two or more of them are used together.

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