JP2000147607A - Optical image pickup device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the speed and the efficiency of succesive processing operations using a frame image higher, in a visual inspection of a carried matter and to take the image of plural carried matters on the frame image with high difinition. SOLUTION: In this optical image pickup device, the image of two carried matters B is taken on one frame image, by simultaneously capturing reflected light beams from two adjacent carried matters B with a single CCD light- receiving surface 6 where plural carried matters B are carried at regular intervals T1. The device is equipped with an optical lens 4 for forming the image of two adjacent carried matters B on the CCD light-receiving surface 6 while transmitting the respective reflected light beams from two adjacent carried matters B, and 3rd and 4th refracting bodies 22 and 23 making emitted light beams R1a and R2a approach each other and guiding them to the lens 4, by causing the respective reflected light beams advancing to the lens 4 to refract from two adjacent carried matters B, while making them incident as incident light beams R1 and R2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical image pickup apparatus and an optical image pickup method for photographing a plurality of conveyed objects conveyed at regular intervals on one frame image in an appearance inspection of an electronic component or the like. About.

[0002]

2. Description of the Related Art Conventionally, an optical image pickup device equipped with a CCD or the like has been used for inspecting the appearance of electronic components such as chip resistors, for example. From a transport line which is transported side by side at a constant interval, electronic components as transported objects are imaged by a CCD.

In the appearance inspection of a conveyed object using such an optical image pickup apparatus, a method of photographing a plurality of conveyed objects on the same frame image has been adopted from the viewpoint of speeding up the inspection work and increasing efficiency. I have. In such a method, a plurality of conveyed objects that have reached a predetermined position on the convey line are captured by the optical imaging device in the same frame image. Thereafter, the frame images obtained from the optical imaging device are sequentially subjected to predetermined image processing and displayed on a monitor screen, and a visual inspection on a predetermined number of conveyed objects is collectively performed for each frame image displayed on the monitor screen. It has been done.

FIG. 12 is a schematic explanatory view showing an optical system in a conventional optical imaging apparatus. As shown in FIG. 12, a situation in which a plurality of articles B are conveyed at a constant interval T is shown. For example, two of them are imaged at a predetermined position by an optical imaging device. Specifically,
In the optical imaging device shown in this figure, a range including two conveyed objects is set as a target region TG, and totally reflected light from the target region TG is transmitted through a lens 92. The reflected light transmitted through the lens 92 is guided to a CCD light receiving surface 94 through an aperture stop 93, and the CCD light receiving surface 9
4 shows a state in which an image of each transported object B is formed. In other words, the two conveyed objects B are C
Based on the charge signal from the CD light-receiving surface 94, the image is shot in one frame image and is shot in one frame image.
The images of the transported objects B are displayed on the monitor screen together with the inter-image portion at the interval αT obtained by multiplying the actual interval T by the magnification α.

FIG. 13 is an explanatory view showing a frame image displayed on a monitor screen by a conventional optical imaging device. As shown in FIG. The image αB of the individual conveyed objects B is displayed in a state where the image αB fits in the entire monitor screen, and the inter-image portion BB at the interval αT is also displayed in a state where it fits in the entire monitor screen.

[0006]

However, in the above-mentioned conventional optical imaging apparatus, when a frame image obtained by simultaneously capturing the images of two conveyed objects is displayed on a monitor screen, as shown in FIG. Inter-image part BB together with image αB of each conveyed object B
Are simultaneously displayed with an interval αT. Then, in order to improve the inspection accuracy, if the magnification α is increased to increase the image αB of each transported object B to increase the definition, the interval αT between the inter-image portions BB is also increased according to the magnification α. Increased and projected. Therefore, the image αB of each transported object B is displayed in accordance with the enlargement ratio α within the allowable limit with a margin in the monitor screen under the restriction of the increasing interval αT in addition to the restriction of the monitor screen size. The Rukoto. In other words, in a frame image in which a plurality of transported objects are simultaneously captured, an inter-image portion BB at an interval αT corresponding to the actual interval T is captured together with the image of each transported object. However, it is not possible to display the image αB of each transported object B with a sufficiently large size on the entire monitor screen, and it is hardly possible to increase the resolution of the images αB of the plurality of transported objects B. there were.

The present invention was conceived in view of the above-mentioned circumstances, and by capturing images of a plurality of conveyed objects on one frame image, the speed of a sequential processing operation using the frame images is improved. It is an object of the present invention to provide an optical imaging apparatus and an optical imaging method capable of realizing high resolution and efficiency, and capable of taking high-resolution images of a plurality of conveyed objects with respect to a frame image. .

[0008]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

In other words, the optical imaging device provided by the first aspect of the present invention provides a light receiving surface for reflecting light from each conveyed object in a situation where a plurality of conveyed objects are conveyed at a constant interval. An optical imaging device that captures the plurality of objects in one frame image by capturing at the same time, while transmitting each reflected light from the plurality of objects, A lens that forms an image of each conveyed object, and a light beam shaping unit that guides the light beam paths of the respective reflected lights that advance from the plurality of conveyed objects toward the lens to the one light receiving surface. And characterized in that:

[0010] In the optical imaging apparatus provided by the first aspect in which the above technical means have been taken, reflected light from each conveyed object is simultaneously captured by one light receiving surface, so that the light from the light receiving surface is captured. Based on the charge signal, images of a plurality of objects are captured in one frame image. By using the frame images obtained in this way, the processing operations for a predetermined number of conveyed objects are sequentially and collectively performed for each frame image. Further, each reflected light that passes through the lens and advances from a plurality of conveyed objects to the light receiving surface is guided to the light receiving surface along the light beam paths approaching each other by the light beam shaping means. That is, the reflected light from the interval between the conveyed objects does not reach the light receiving surface in a state where it is partially removed by the light beam shaping means, and the inter-image portion corresponding to the actual interval is:
This means that the frame image cannot be completely taken. As a result, a large image of each conveyed object is captured in one frame image, and when the frame image is enlarged and displayed on, for example, a monitor screen, the image of each conveyed object is displayed on the entire monitor image. Will be displayed with a sufficiently large size.

Therefore, according to the optical imaging apparatus provided by the first aspect of the present invention, since a plurality of images of a conveyed object are photographed in one frame image, the frame image thus obtained is obtained. By using the method, the speed and efficiency of the sequential processing can be increased. Moreover,
In one frame image, the image of each transported object is largely captured without an extra inter-image portion corresponding to the actual interval between the transported objects being completely captured, so that the frame image is For example, when enlarged and displayed on a monitor screen or the like, the image of each conveyed object is displayed with a sufficiently large size with respect to the entire monitor image. You can take a copy.

As the transported object, for example, an electronic component such as a chip resistor, which is an object to be inspected for appearance, is suitable. However, other transported objects can of course be applied.

The light receiving surface is, for example, CC
A light receiving surface constituted by light receiving elements such as D is suitable, but is not particularly limited to a CCD, and may be constituted by other light receiving elements.

[0014] In a preferred embodiment, the light beam shaping means is constituted by a reflector which reflects the reflected light beams to bring the light beam paths closer to each other.

According to such an embodiment, each reflected light from each conveyed object travels to the lens along the luminous flux path. At this time, the luminous flux path serving as the optical path of each reflected light is The reflectors are directed toward one light receiving surface in a state in which they approach each other by reflecting each reflected light. In other words, since the reflected light from the space between the conveyed objects is partially removed from between the light beam paths approaching via the reflector, an inter-image portion corresponding to the actual space is provided. Is completely captured in a frame image, and a large image of each transported object can be reliably captured for one frame image.

In another preferred embodiment, the light beam shaping means is constituted by a refractor which refracts each of the reflected lights to bring the light beam paths closer to each other.

According to such an embodiment, each reflected light from each conveyed object travels to the lens along the luminous flux path. At this time, the luminous flux path which is the optical path of each reflected light is The refractor refracts each reflected light to approach one light receiving surface in a state of approaching each other. In other words, since the reflected light from the space between the conveyed objects is partially removed from between the light flux paths approaching via the refractor, the inter-image portion corresponding to the actual space is provided. Is completely captured in a frame image, and a large image of each transported object can be reliably captured for one frame image.

In still another preferred embodiment, the light beam shaping means is provided between the one light receiving surface and the lens.

According to such an embodiment, since the light beam shaping means is provided between the one light receiving surface and the lens,
Each reflected light from a plurality of conveyed objects converges by passing through the lens, and then is guided to one light receiving surface while approaching each other via the light beam shaping means, and is positioned closer to the light receiving surface side than the lens. Since the images of the conveyed objects are brought close to each other, the images of the conveyed objects can be formed on the light receiving surface with high definition.

Further, in the optical imaging method provided by the second aspect of the present invention, in a situation where a plurality of conveyed objects are conveyed at a constant interval, reflected light from each conveyed object is converted into one light receiving surface. In the optical imaging method of capturing the plurality of objects in one frame image at the same time, while transmitting each reflected light from the plurality of objects to a lens,
When forming an image of each transported object on the one light receiving surface,
It is characterized in that the luminous flux paths of the reflected light traveling from the plurality of conveyed objects toward the lens are brought closer to each other and guided to the one light receiving surface.

In the optical imaging method provided by the second aspect in which the above technical means are employed, reflected light from each conveyed object is simultaneously captured by one light receiving surface, and a charge signal from the light receiving surface is captured. , Images of a plurality of conveyed objects are taken on one frame image. If the frame images obtained in this way are used, the processing operation for a predetermined number of conveyed objects will be sequentially and collectively performed for each frame image. In addition, each reflected light from a plurality of conveyed objects travels to the light receiving surface while passing through the lens, so that an image of each conveyed object is formed on the light receiving surface. The light travels toward one light receiving surface along the light flux paths approaching each other. In other words, the reflected light from the gap between the conveyed objects does not reach the light receiving surface in a state where it is partially removed, and the inter-image portion corresponding to the actual gap is completely copied to the frame image. It will not be taken. As a result, a large image of each conveyed object is captured in one frame image, and when the frame image is enlarged and displayed on a monitor screen, for example, the image of each conveyed object is displayed on the entire monitor screen. Will be displayed with a sufficiently large size.

Therefore, according to the optical imaging method provided by the second aspect of the present invention, the same effect as that obtained by the optical imaging apparatus provided by the first aspect of the present invention can be obtained. Can be.

Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred first to first aspects of the present invention will be described.
The fourth embodiment will be specifically described with reference to the drawings.

FIG. 1 is an explanatory diagram showing a use form of the optical imaging apparatus according to the first embodiment of the present invention,
The optical imaging device A is used for performing an appearance inspection of chip resistors (hereinafter, referred to as “transported objects”) B that are transported along the transport direction F in a state of being arranged at a constant interval T. . The optical imaging device A sets a predetermined range at a predetermined position on a transport line as a target area TG, and simultaneously captures a predetermined number of conveyed objects B reaching the target area TG by a CCD imaging method. Such an optical imaging device A is connected to an image processing device C that sequentially performs image processing on a frame image of a conveyed object B and performs an appearance inspection, and the image processing device C includes an optical imaging device. A CRT monitor C1 for displaying a frame image obtained by the device A as an output image is provided. The monitor screen of such a CRT monitor C1 has a fixed resolution of, for example, 640 × 480 pixels. Note that the interval T between the adjacent transported objects B is set to be much larger than the dimension of the transported object B.

FIG. 2 is an explanatory view showing an optical system inside the optical imaging device A according to the first embodiment. As shown in FIG. It is provided with first and second reflectors 2 and 3, an optical lens 4, an aperture stop 5, a CCD light receiving surface 6, and the like.

The light source 1 is arranged so as to irradiate the irradiation light to two objects B in the target area TG on the conveyance line.

The first and second reflectors 2 and 3 use incident light R1 and R2 as light reflected on the two conveyed objects B in the target area TG and the periphery thereof, respectively.
The reflected light R1a, R2
a are brought close to each other and guided to an optical lens 4 described later. Outgoing light R1a, R2a from these incident light R1, R2
The light path until the light reflected by each conveyed object B reaches the lens surface of the optical lens 4 is a light beam path, and the first and second reflectors 2 and 3 respectively pass the light paths. And a light beam shaping means for guiding the light beam to the optical lens 4.

The first and second reflectors 2 and 3 will be described more specifically. Each of the first and second reflectors 2 and 3 is constituted by a prism having a substantially parallelogram cross section. Have been. 2a, 2b and 3a, 3b in the first and second reflectors 2, 3, respectively
Is a total reflection surface (hereinafter referred to as a downward mirror surface 2).
a, 3a, upward mirror surfaces 2b, 3b). That is, in the first stage of the reflection by the first and second reflectors 2 and 3, the incident lights R1 and R2 from the transport object B located forward and rearward with respect to the transport direction F are reflected by the downward mirror surface 2a. , 3a, the light is reflected substantially at a right angle, so that the light travels along the horizontal direction while approaching and approaching each other. In the second stage of reflection, the incident lights R1 and R2 reflected through the downward mirror surfaces 2a and 3a are reflected again at substantially right angles through the upward mirror surfaces 2b and 3b, so that they are parallel to each other. It goes up vertically while rising. Finally, after the incident lights R1 and R2 are reflected by the upward mirror surfaces 2b and 3b, the outgoing lights R1a and R1 of the parallel light flux are reflected.
The light reaches the optical lens 4 as 2a. That is, the light beam paths from the incident lights R1 and R2 to the outgoing lights R1a and R2a are formed such that the light path is narrowed from the incident path distance RT to the smaller outgoing path distance RTa.

The optical lens 4 converges the light beams R1a and R2a emitted from the first and second reflectors 2 and 3 and forms an image of each conveyed object B on a CCD light receiving surface 6 described later. Lens.

The aperture stop 5 is arranged in view of the optical positional relationship between the optical lens 4 and a CCD light receiving surface 6 described later, and focuses on the CCD light receiving surface 6 while restricting the light beam from the optical lens 4. In order to form a focused image, it is arranged at a position that has a desired depth of focus.

Here, as an optical positional relationship between the optical lens 4 and the aperture stop 5, a telecentric optical system is employed. The telecentric optical system refers to an optical system arranged such that a principal ray (a ray passing from a target point off the optical axis and passing through the center of the aperture stop 5) passes through a focal point. In other words, by using this telecentric optical system, only the reflected light traveling in parallel from the transported object B can be used as the first light
And the aperture stop 5 while passing through the second reflectors 2 and 3.
And reaches the CCD light receiving surface 6 to be described later, even if the conveyed object B changes in the optical axis direction.
It is assumed that the size of the image above does not change.

The CCD light-receiving surface 6 is a light-receiving surface in which a number of CCD elements are arranged in pixels, and accumulates charges corresponding to the intensity of light received from the optical lens 4 via the aperture stop 5. The charge signal from the CCD light receiving surface 6 is amplified by an amplifier (not shown) to finally generate a frame image capturing two images of the conveyed object, and the frame image is transmitted to the image processing device C. Will be output.

Next, the operation of the optical system of the optical imaging apparatus according to the first embodiment will be described with reference to FIG. 2 and FIG.

First, as shown in FIG.
When the two transported objects B reach the target area TG with the above, the light reflected by each transported object B is incident on the first and second reflectors 2 and 3 as incident lights R1 and R2.

At this time, the incident lights R1 and R2 are reflected a predetermined number of times inside the first and second reflectors 2 and 3, so that the optical lens 4 is converted into parallel light beams R1a and R2a approaching each other. , And the reflected light from the portion corresponding to the interval T between the adjacent transported objects B is partially removed without passing through the first and second reflectors 2 and 3 and the optical lens 4. State.

The outgoing lights R1a and R2a that have reached the optical lens 4 in a state of approaching each other are received by the CCD light receiving surface 6 via the aperture stop 5 while being converged on the optical lens 4. . In other words, the images of two adjacent transported objects B are formed on the CCD light receiving surface 6 in a state of being extremely close to each other, and are also adjacent to the frame image formed according to the charge signal from the CCD light receiving surface 6. The two images of the transported object B are largely captured in a state where they are close to each other.

FIG. 3 is an explanatory view showing a state where a frame image formed by the CCD light receiving surface 6 shown in FIG. 2 is output and displayed on a monitor screen. As shown in FIG.
In the frame image displayed on the monitor screen of the T monitor C1, images of two adjacent transported objects B are displayed as an enlarged image αB enlarged at an enlargement factor α.

Here, according to the ordinary imaging method, the portion corresponding to the actual interval T between the adjacent conveyed objects B is the magnification α
12, the inter-image portion BB is projected on the monitor screen at an interval αT (FIG. 12).
), Since the image αB of the transported object B is formed on the CCD light receiving surface 6 in a state in which the image αB is closer than the actual interval T, the interval between the image portions BB is determined by the conventional imaging method. In this case, the image is projected with an interval βT narrower than αT. That is, in a state where the frame image is displayed in an enlarged manner to the maximum, the enlarged images αB of two adjacent conveyed objects are displayed with a sufficiently large size on the entire monitor screen of the CRT monitor C1.

Therefore, according to the optical imaging apparatus A according to the first embodiment, two optical images adjacent to one frame image
Since the image αB of the individual transported object B is captured and taken, the speed and efficiency of the appearance inspection of the transported object B performed sequentially can be improved by using the frame image obtained in this way.

Further, in one frame image, an extra inter-image portion B-corresponding to the interval T between two adjacent conveyed objects B.
B is hardly photographed, and an image α of each transported object B is obtained.
Since B is photographed largely on the frame image, when the frame image is enlarged and displayed on the CRT monitor C1, the image αB of each transported object B is displayed with a sufficiently large size on the entire monitor image. The image αB of a predetermined number of the conveyed objects B adjacent to the frame image can be captured with high definition.

Next, an optical imaging device according to a second embodiment of the present invention will be described. Note that the optical imaging device according to the second embodiment has the same usage as the optical imaging device A shown in FIG.
It is assumed that the sheet is being conveyed at an interval T1 smaller than the interval T shown in FIG. The same members as those in the first embodiment are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

FIG. 4 is an explanatory view showing an optical system inside the optical imaging apparatus according to the second embodiment of the present invention. The optical imaging apparatus according to the second embodiment shown in FIG. Are the first and the second in the first embodiment.
The first and second refractors 12, 13 are provided between the optical lens 4 and the target area TG in place of the reflectors 2, 3.

The first and second refractors 12 and 13 use the light reflected on the two conveyed objects B in the target area TG and the periphery thereof as incident lights R1 and R2, and convert the incident lights R1 and R2 into the incident lights R1 and R2. Outgoing light R1a, R
2a are led to the optical lens 4 by approaching each other.
The optical paths from the incident lights R1 and R2 to the outgoing lights R1a and R2a are light beam paths until the light reflected by each conveyed object B reaches the lens surface of the optical lens 4, and the first and second light paths.
Each of the refractors 12 and 13 realizes a light beam shaping unit that guides the light beam paths to the optical lens 4 by approaching each other.

The first and second refractors 12, 13 will be described more specifically. Each of the first and second refractors 12, 13 is formed of a flat plate of optical glass having a predetermined thickness. ing. When the sectional structures of the first and second refractors 12 and 13 are viewed from a direction orthogonal to the transport direction F (a state viewed from the front surface in the drawing), the first
And the second refractors 12 and 13 are provided in the target region TG.
Are arranged and integrated in a valley shape symmetrical with respect to the central portion of the refractors 12, 13 and the respective incident surfaces 12a, 1
3a and the emission surfaces 12b and 13b are configured to form a predetermined angle θ with each other. That is, the entrance surfaces 12a, 13a of the first and second refractors 12, 13, respectively.
In the above, incident light R1, R2 from the transported object B located forward and rearward with respect to the transport direction F is incident at a predetermined incident angle, and the incident light R1, R2 is refracted in a direction in which they inward. Then, the light gradually advances toward the emission surfaces 12b and 13b. Finally, the incident light R1,
R2 is refracted again by the emission surfaces 12b and 13b of the first and second refractors 12 and 13, respectively, and advances in the vertical direction in parallel with each other. Each is a parallel light beam R1
The light reaches the optical lens 4 as a and R2a. That is, the light beam paths from the incident lights R1 and R2 to the outgoing lights R1a and R2a are formed with the light path slightly narrowed to the outgoing path interval RTb smaller than the incoming path interval RT1.

Here, the optical positional relationship between the optical lens 4 and the aperture stop 5 in the second embodiment can be expressed as follows.
A telecentric optical system is adopted, and only the reflected light traveling in parallel from the conveyed object B passes through the center of the aperture stop 5 while passing through the first and second refractors 12 and 13 and will be described later. The image reaches the CCD light receiving surface 6 and the size of the image on the CCD light receiving surface 6 does not change even if the conveyed object B changes in the optical axis direction.

Next, the operation of the optical system of the optical imaging apparatus according to the second embodiment will be described with reference to FIGS.

First, as shown in FIG.
When the two transported objects B reach the target area TG with 1, the light reflected by each transported object B enters the first and second refractors 12 and 13 as incident lights R1 and R2.

At this time, the incident lights R1 and R2 are refracted inside the first and second refractors 12 and 13 to reach the optical lens 4 as outgoing lights R1a and R2a of parallel light beams approaching each other. That is, the reflected light from the interval T <b> 1 between the conveyed objects B is guided to the optical lens 4 in a slightly overlapping state.

The outgoing lights R1a and R2a that have reached the optical lens 4 in the approaching state are received by the CCD light receiving surface 6 via the aperture stop 5 while being converged on the optical lens 4. That is, the CCD light receiving surface 6 has two adjacent
The images of the two conveyed objects B are formed in a state where the images of the two conveyed objects B are slightly close to each other, so that the image of the two adjacent conveyed objects B is also formed in the frame image formed according to the charge signal from the CCD light receiving surface 6. A large shot will be taken with the camera slightly approaching.

FIG. 5 is an explanatory view showing a state in which a frame image formed by the CCD light receiving surface 6 shown in FIG. 4 is output and displayed on a monitor screen. As shown in FIG.
In the frame image displayed on the monitor screen of the T monitor C1, images of two adjacent transported objects B are displayed as an enlarged image αB enlarged at an enlargement factor α.

Here, according to the normal imaging method, the portion corresponding to the actual interval T1 between the adjacent transported objects B is also enlarged with the enlargement factor α, so that the inter-image portion BB has the interval αT1. Although the image is conveyed (see FIG. 12), since the image of the conveyed object B is formed on the CCD light receiving surface 6 in a state slightly closer to the actual interval T1, an inter-image portion B-B is formed. Is projected with an interval γT1 that is somewhat smaller than αT1. That is,
In a state where the frame image is enlarged and displayed to the maximum, the enlarged images αB of two adjacent conveyed objects are displayed larger than usual on the entire monitor screen of the CRT monitor C1.

Therefore, even in the optical imaging apparatus according to the second embodiment, an extra inter-image portion BB corresponding to the interval T1 between two adjacent conveyed objects B is reduced in one frame image. The image αB of each conveyed object B is photographed larger than usual with respect to the frame image by taking a picture in a state where the image is conveyed, and when the frame image is enlarged and displayed on the CRT monitor C1, the image αB Is displayed with a sufficient size on the entire monitor image, and images αB of a predetermined number of conveyed objects B adjacent to the frame image can be taken with high definition.

Further, in the second embodiment, unlike the first embodiment described above, the interval T1 between the adjacent conveyed objects B is not set so large as compared with the size of the conveyed object B. The first and second refractors 12 and 13 having the thickness of the optical lens 4 and the target region TG
, It is possible to cope with a simple structure even when the transported object B is being transported at a narrow interval.

Although the first and second refractors 12 and 13 shown in FIG. 4 are used, the first and second refractors 12 and 13 are optically different from the arrangement shown in FIG. An experimental result was obtained that when the lens was disposed between the lens 4 and the CCD light receiving surface 6, the image αB of the transported object B could be captured with the highest definition.

FIG. 6 is an explanatory view showing a modification of the second embodiment. As shown in FIG. 6, the first and second refractors 12 and 13 are CCDs (not shown). The optical lens 4 and the CCD light receiving surface 6 are attached to itself.
, And the optical positional relationship of the telecentric system is maintained on both sides of the conveyed object B and the image on the CCD light receiving surface 6. In such a case, the outgoing light Rb transmitted through the optical lens 4 is refracted by the first and second refractors 12 and 13 so as to reach the optical lens 4 as outgoing light Rc approaching each other. Become.
In other words, since the images αB of the objects B are close to each other at a position closer to the CCD light receiving surface 6 side than the optical lens 4, the image αB of each object B is high on the CCD light receiving surface 6. It is imaged finely.

Further, an optical imaging device according to a third embodiment of the present invention will be described. Note that the optical imaging device according to the third embodiment is also in the same usage form as the optical imaging device A shown in FIG. 1 as in the second embodiment. Are transported at an interval T1 smaller than the interval T shown in FIG. Also, the first
In the drawings, the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 7 is an explanatory diagram showing an optical system inside the optical imaging apparatus according to the third embodiment of the present invention. The optical imaging apparatus according to the third embodiment shown in FIG. Are the first and the second in the first embodiment.
Are replaced by third and fourth refractors 22, 23 between the optical lens 4 and the target area TG.

The third and fourth refractors 22 and 23 use the two objects B in the target area TG and the light reflected on the periphery thereof as incident lights R1 and R2, and convert the incident lights R1 and R2 into the incident lights R1 and R2. Outgoing light R1a, R
2a are led to the optical lens 4 by approaching each other.
The optical path from the incident light R1, R2 to the outgoing light R1a, R2a is a light beam path until the light reflected by each conveyed object B reaches the lens surface of the optical lens 4, and the third and fourth light paths.
Each of the refractors 22 and 23 realizes a light beam shaping unit that guides the light beam paths to the optical lens 4 by approaching each other.

The third and fourth refractors 22 and 23 will be described more specifically. Each of the third and fourth refractors 22 and 23 is formed of a flat plate of optical glass having a predetermined thickness. ing. When the sectional structures of the third and fourth refractors 22 and 23 are viewed from a direction perpendicular to the transport direction F (a state viewed from the front surface in the drawing), the third
In addition, the fourth refractors 22 and 23 are integrated while being kept at a predetermined angle λ with respect to the transport surface. In particular, the fourth refractor 23 has a region substantially half the target region TG. Are joined on the inclined surface of the third refractor 22 near the optical lens 4. The entrance surface 22a and the exit surface 22b of the third refractor 22 cover almost the entire target region TG, and
The incident surface 23a and the outgoing surface 23b of the refractor 23 of this example are in a state of covering substantially half of the target region TG. That is, the incident lights R1 and R2 from the transport object B located forward and rearward with respect to the transport direction F enter the entire incident surface 22a of the third refractor 22 at a predetermined incident angle, and the incident lights R1 and R2 enter the incident light R1 and R2. The lights R1 and R2 are refracted in the same direction and proceed to the emission surface 22b. The incident light R1 emitted from the emission surface 22b is refracted again by the emission surface 22b, and rises as emission light R1a having a shifted optical axis along the vertical direction from the emission surface 22b. On the other hand, the other incident light R2 exiting from the exit surface 22b further enters the entrance surface 23a of the fourth refractor 23, and is refracted again by the exit surface 23b of the fourth refractor 23. The emitted light R2a is shifted upward from the emission surface 23b in the vertical direction as the emitted light R2a having a larger optical axis deviation than the emitted light R1a. Simply put, finally, the incident light R1, R2
Are parallel output lights R1 whose optical axes are shifted in the same direction.
The light beams R2a reach the optical lens 4 as a and R2a. One of the outgoing light beams R2a reaches the optical lens 4 in a state where the optical axis is shifted more than the other outgoing light beam R1a. That is, the luminous flux paths from the incident lights R1, R2 to the outgoing lights R1a, R2a have an exit path distance RT smaller than the entrance path interval RT1.
The optical path is formed in a state slightly narrowed to c.

Here, also in the third embodiment,
As the optical positional relationship between the optical lens 4 and the aperture stop 5, a telecentric optical system is adopted, and only the reflected light traveling in parallel from the conveyed object B is the third and fourth optical elements.
And passes through the center of the aperture stop 5 to reach the CCD light receiving surface 6 described later while passing through the refractors 22 and 23 of FIG.
It is assumed that the size of the image on the CCD light receiving surface 6 does not change even if the conveyed object B changes in the optical axis direction. The third
In the embodiment of the present invention, the reflected light from each transported object B to the optical lens 4 is transmitted through only one of the third refractors 22 or both the third and fourth refractors 22 and 23. The optical path length differs for each transported object B. In such a case, it is difficult to form both images of the transported object B with good focus. However, the optical path lengths of the reflected light from each transported object B are matched to form the images of both transported objects B. In order to focus well, the emitted light R1a
A refractor having a predetermined thickness may be arranged in the middle of the optical path, and the refractor may transmit outgoing light R1a. Then, the reflected light from both the transported objects B travels along the optical path lengths substantially coincident with each other, so that the images of both the transported objects B are formed with good focus on the CCD light receiving surface 6. .

Next, the operation of the optical system of the optical imaging device according to the third embodiment will be described with reference to FIGS.

First, as shown in FIG.
When the two transported objects B reach the target area TG with 1, the incident light R1 from the transported object B positioned forward with respect to the transport direction F enters the third refractor 22,
Incident light R2 from the transported object B located rearward in the transport direction F is incident on the third and fourth refractors 22,23.

At this time, the incident lights R1 and R2 reach the optical lens 4 in a state where they are refracted in the same direction while being parallel to each other by being incident on the third refractor 22 maintained at a predetermined angle λ. The one incident light R2, unlike the other incident light R1, is refracted by the thickness of the fourth refractor 23 and reaches the optical lens 4 in a shifted state. That is, the incident lights R1 and R2 are output light R of a parallel light flux approaching each other.
The reflected light from the portion of the interval T1 between the adjacent conveyed objects B is guided to the optical lens 4 in a slightly overlapping state as 1a and R2a.

The outgoing lights R1a and R2a that have reached the optical lens 4 in the approaching state are received by the CCD light receiving surface 6 via the aperture stop 5 while being converged on the optical lens 4. That is, the CCD light receiving surface 6 has two adjacent
The images of the two conveyed objects B are formed in a state where the images of the two conveyed objects B are slightly close to each other, so that the image of the two adjacent conveyed objects B is also formed in the frame image formed according to the charge signal from the CCD light receiving surface 6. A large shot will be taken with the camera slightly approaching.

FIG. 8 is an explanatory view showing a state in which the frame image formed by the CCD light receiving surface 6 shown in FIG. 7 is output and displayed on a monitor screen. As shown in FIG.
In the frame image displayed on the monitor screen of the T monitor C1, images of two adjacent transported objects B are displayed as an enlarged image αB enlarged at an enlargement factor α.

Here, according to the ordinary imaging method, the actual interval T1 between the adjacent conveyed objects B is also enlarged with the enlargement factor α, so that the inter-image portion BB is captured with the interval αT1. (See FIG. 13)
Is slightly closer to CC than the actual interval T1.
Since the image is formed on the D light receiving surface 6, a portion B-
The interval B is projected with an interval δT1 that is somewhat smaller than αT1. That is, in a state where the frame image is enlarged and displayed to the maximum, the enlarged images αB of two adjacent conveyed objects are displayed with a sufficient size on the entire monitor screen of the CRT monitor C1.

Therefore, even with the optical imaging apparatus according to the third embodiment, an extra inter-image portion BB corresponding to the interval T1 between two adjacent conveyed objects B is actually included in one frame image. The photograph is taken smaller than the enlarged size of. As a result, the image αB of each transported object B can be copied to the frame image larger, so that the frame image is
When enlarged and displayed on the T monitor C1, the image α of each transported object B is displayed.
B can be displayed with a sufficient size on the entire monitor image, and a predetermined number of images αB of the conveyed objects B adjacent to the frame image can be captured with high definition.

Also, in the third embodiment, similarly to the above-described second embodiment, the interval T
1 is not set so much wider than the size of the transported object B, but by providing the third and fourth refractors 22 and 23 having a certain thickness between the optical lens 4 and the target area TG, Even in the case where the transported object B is transported at such a narrow interval, it can be handled with a simple structure.

Further, an optical imaging device according to a fourth embodiment of the present invention will be briefly described.

FIG. 9 is an explanatory diagram showing a use form of the optical imaging apparatus according to the fourth embodiment of the present invention.
The optical imaging device A1 shown in FIG.
2, a predetermined number of the objects B, which are being transported along the transport direction F in a state of being arranged in two rows at T3, are imaged in the target area TG. Note that the optical imaging device A1 according to the fourth embodiment is used in substantially the same manner as the optical imaging device A shown in FIG. ing. Further, the same members as those in the first to third embodiments are denoted by the same reference numerals in the drawings, and the description thereof is partially omitted.

FIG. 10 is a perspective view showing an optical system inside an optical imaging device A1 according to the fourth embodiment. The optical imaging device A1 according to the fourth embodiment shown in FIG. This is adopted as a modification of the second embodiment. Inside the optical imaging device A1, between the optical lens (not shown) and the target area TG, each of the four flat rhombus-shaped pyramidal refractors 30a to 30d is formed at a predetermined same angle with respect to the transport surface. It is arranged integrally while being kept. Pyramidal refractors 30a to 30d
Are arranged with their tip vertices facing substantially the center of the target area TG. That is, four pyramidal refractors 3
In the structure in which 0a to 30d are integrated, the bottom surface of the quadrangular pyramid and the periphery of its four corners are removed, and each of the pyramidal refractors 30a to 30d has a target area TG Are arranged so as to cover the periphery of the four transported objects B. The pyramid-shaped refractors 30a to 30d having such an arrangement structure have substantially the same functions and effects as the first and second refractors 12 and 13 in the above-described second embodiment. That is, the pyramidal refractor 30
a to 30d are formed of the same optical glass as the first and second refractors 12 and 13 described in the second embodiment, and the first and second refractors 12 and 13 are used. Is characterized by a point different from the arrangement structure.

Each of the pyramidal refractors 30a to 30d converts incident light S1 to S4 into light reflected from four conveyed objects B in the target area TG and the periphery thereof, and the incident light S1 to S4.
Outgoing light S1a to S4a by refracting
Are brought closer to each other and led to the optical lens. The optical path from the incident light S1 to S4 to the outgoing light S1a to S4a is 4
This is a light beam path until the light reflected by each of the conveyed objects B reaches the lens surface of the optical lens, and is a pyramidal refractor 30a to 30c.
Each of 30d realizes a light beam shaping unit that guides the light beam paths to each other and guides them to the optical lens.

That is, in the fourth embodiment, each of the pyramidal refractors 30a to 30d causes the reflected lights from the four transported objects B to approach each other, so that the outgoing light S1a from the incident lights S1 to S4. The light flux paths to S4a are guided to the optical lens in a state of approaching each other.

FIG. 11 is an explanatory diagram showing a state where the frame image obtained by the structure shown in FIG. 10 is output and displayed on the monitor screen. As shown in FIG. 11, the frame image is displayed on the monitor screen of the CRT monitor C1. The image of the four conveyed objects B adjacent to each other is displayed as an enlarged image αB enlarged at an enlargement ratio α in the frame image thus obtained.

Here, according to the ordinary imaging method, the actual distances T2 and T3 between the conveyed objects B vertically and horizontally are also equal to the enlargement ratio α.
, The inter-image portion BB is projected at intervals αT2 and αT3. However, the image αB of the transported object B is slightly closer than the actual intervals T2 and T3, Therefore, the interval between the inter-image portions BB is projected with the intervals εT2 and εT3 somewhat smaller than αT2 and αT3. That is, in a state where the frame image is maximally enlarged and displayed, the enlarged images αB of the four conveyed objects adjacent to each other are CR.
The entire monitor screen of the T monitor C1 is displayed larger than usual.

Therefore, according to the optical imaging apparatus A1 according to the fourth embodiment, the images of the four conveyed objects B adjacent to each other are captured in one frame image, and the frame obtained in this manner is obtained. If an image is used, the speed and efficiency of the appearance inspection of the conveyed object B can be significantly increased as compared with the first to third embodiments.

Further, an extra inter-image portion BB corresponding to the intervals T2 and T3 between the four conveyed objects B adjacent to each other is photographed in one frame image in a slightly reduced state. Since the image αB of each conveyed object B can be displayed larger than usual on the monitor screen, when the frame image is enlarged and displayed on the CRT monitor C1, the image αB of each conveyed object B is sufficiently large for the entire monitor image. As a result, a large number of images αB of the transported objects B can be captured with high definition with respect to the frame images.

In each of the above embodiments, two adjacent units or four adjacent units in two rows are arranged.
Although the configuration is such that the images of the conveyed objects B are taken and taken, the number is not particularly limited. For example, when the conveyed objects are conveyed in a line, three or more images of the conveyed objects are formed. On the other hand, when the articles are conveyed in two rows, images of up to six or more conveyed articles up to the third piece may be taken along the conveying direction. Further, the present invention can be applied to a situation where the articles are conveyed in a state of being arranged in three or more rows.

Further, in the first embodiment, the first and second reflectors 2 made of a prism having a reflection function are provided in order to make the reflected light from the conveyed object approach each other.
3 is used, but without using such a prism reflector, the total reflection surfaces 2a, 2b and 3a, 3a,
It is also possible to adopt a structure in which a mirror having a mirror surface is arranged at a position 3b.

Furthermore, if the thickness of the refractor used in the second to fourth embodiments is made considerably thick, it is possible to make the reflected light from each conveyed object closer.

Further, in the fourth embodiment,
Four flat rhombic pyramid-shaped refractors 30a to 30d are provided. However, even if the flat rhombus is not a flat rhombus, if it is an arrangement structure capable of refracting reflected light from four adjacent conveyed objects, for example, a triangular shape The four refractors may be combined to form a quadrangular pyramid-like overall structure.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a use form of an optical imaging device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an optical system inside the optical imaging device A according to the first embodiment.

FIG. 3 is an explanatory diagram showing a state where a frame image formed by a CCD light receiving surface shown in FIG. 2 is output and displayed on a monitor screen.

FIG. 4 is an explanatory diagram showing an optical system inside an optical imaging device according to a second embodiment of the present invention.

5 is an explanatory diagram showing a state where a frame image formed by the CCD light receiving surface shown in FIG. 4 is output and displayed on a monitor screen.

FIG. 6 is an explanatory diagram showing a modification of the second embodiment.

FIG. 7 is an explanatory diagram showing an optical system inside an optical imaging device according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a state where a frame image formed by the CCD light receiving surface shown in FIG. 7 is output and displayed on a monitor screen.

FIG. 9 is an explanatory diagram showing a usage pattern of an optical imaging device according to a fourth embodiment of the present invention.

FIG. 10 is a perspective view showing an optical system inside an optical imaging device according to a fourth embodiment.

11 is an explanatory diagram showing a state where a frame image obtained by the structure shown in FIG. 10 is output and displayed on a monitor screen.

FIG. 12 is a schematic explanatory view showing an optical system in a conventional optical imaging device.

FIG. 13 is an explanatory diagram showing a frame image displayed on a monitor screen by a conventional optical imaging device.

[Explanation of symbols]

 A, A1 Optical imaging device B Conveyed object C Image processing device 1 Light source 2 First reflector 3 Second reflector 4 Optical lens 5 Aperture stop 6 CCD light receiving surface 12 First refractor 13 Second refraction Body 22 Third refractor 23 Fourth refractor 30a to 30d Pyramid refractor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA49 BB02 BB15 CC25 DD06 FF01 FF04 FF42 HH12 HH14 JJ03 JJ09 JJ26 LL00 LL04 LL12 LL30 LL46 LL59 SS02 SS13 TT01 UU07 5C022 AA01 AB68 AC42 AC51 A05 CC05 CC04 HA05

Claims (5)

[Claims] In a situation where a plurality of articles are being conveyed at a fixed interval, reflected light from each article is simultaneously captured by one light receiving surface, so that the plurality of articles are conveyed in one frame image. An optical imaging device for photographing an object, wherein a lens that forms an image of each conveyed object on the one light receiving surface while transmitting each reflected light from the plurality of conveyed objects; and An optical imaging device, comprising: a light beam shaping unit that guides the light beam paths of the respective reflected light traveling from the conveyed object toward the lens to the one light receiving surface by approaching each other. 2. The optical imaging apparatus according to claim 1, wherein the light beam shaping means is configured by a reflector that reflects the respective reflected lights to bring the light beam paths closer to each other. 3. The optical imaging apparatus according to claim 1, wherein said light beam shaping means is constituted by a refractor that refracts each of said reflected lights to bring said light beam paths closer to each other. 4. The optical imaging apparatus according to claim 1, wherein said light beam shaping means is provided between said one light receiving surface and said lens. 5. In a situation where a plurality of transported objects are being transported at a constant interval, reflected light from each transported object is simultaneously captured by one light receiving surface, and the plurality of transported objects are captured in one frame image. In the optical imaging method of taking a picture, while transmitting each reflected light from the plurality of conveyed objects to a lens and forming an image of each conveyed object on the one light receiving surface, the plurality of conveyed objects are An optical imaging method, characterized in that the luminous flux paths of the respective reflected lights traveling toward the lens are brought closer to each other and guided to the one light receiving surface.