KR20100128177A - Image formation optical system - Google Patents

Abstract

PURPOSE: An imaging optical system is provided to prevent the inclination of the imaging shape of the target object. CONSTITUTION: A lighting unit(100) offers light to a target object(20). An imaging lens(200) has a imaging optical axis(210) which is parallel with a normal direction. A camera(300) receives the reflected light reflected from the target object through the imaging lens. The camera takes a picture of the image of the target object. Based on the imaging optical axis, the target object is arranged in one side. Based on the imaging optical axis, the camera is arranged in the other side.

Description

Image forming optical system {IMAGE FORMATION OPTICAL SYSTEM}

The present invention relates to an imaging optical system, and more particularly, to an imaging optical system for imaging an image of a target object disposed on one surface of a substrate.

In general, an imaging optical system is a system for imaging an image of a target object disposed on one surface of a substrate. The imaging optical system includes an illumination unit for providing light to the target object and an image of the target object through a reflected light reflected from the target object. And an imaging unit for imaging. The imaging unit may include an imaging lens through which the reflected light passes and a camera configured to capture an image of the target object by receiving the reflected light passing through the imaging lens.

On the other hand, the illumination unit is disposed to be inclined on one side with respect to the target object, the imaging unit is disposed on the other side opposite to the one side with respect to the target object. Therefore, the imaging unit may receive the light generated by the illumination unit and reflected from the target object to capture an image of the target object.

However, as the imaging unit is disposed to be inclined to the other side with respect to the target object, the imaging shape of the target object formed on the imaging unit is formed to be inclined, thereby accurately capturing an image of the target object. Missing problems can occur.

Accordingly, an object of the present invention is to provide an imaging optical system capable of accurately capturing an image of a target object.

An imaging optical system according to an embodiment of the present invention captures an image of a target object disposed on one surface of a substrate, and includes an illumination unit, an imaging lens, and a camera.

The illumination unit provides light to the target object. The imaging lens has an imaging optical axis parallel to the normal direction of one surface of the substrate. The camera receives the reflected light reflected from the target object through the imaging lens to capture an image of the target object. The target object is disposed on one side based on the imaging optical axis, and the camera is disposed on the other side opposite to the one side on the basis of the imaging optical axis.

The camera may include an imaging device configured to capture the planar image of the target object by receiving the reflected light passing through the imaging lens, and the horizontal axis of the imaging device may be perpendicular to a normal direction of one surface of the substrate.

The imaging lens and the camera unit are disposed on one side with respect to the central axis passing through the center of the target object in parallel with the normal direction of one surface of the substrate, and the illumination unit is disposed on the other side opposite to the one side with respect to the central axis. Can be.

The imaging optical system may further include a projection lens disposed between the target object and the illumination unit to project light generated by the illumination unit to the target object. In this case, the projection optical axis of the projection lens may be parallel to the normal direction of one surface of the substrate. In addition, the imaging lens and the projection lens may be disposed at positions symmetrical with respect to the central axis.

The imaging optical system may further include a grating unit disposed between the projection lens and the illumination unit to change the light generated by the illumination unit into grating image light and provide the grating image light to the projection lens. In this case, the imaging device and the grating unit may be disposed at positions symmetrical with respect to the central axis. In addition, the imaging optical system may further include a grating transfer unit coupled to the grating unit to move the grating unit.

The target object may be a surface-mount device (SMD) mounted on one surface of the substrate.

According to the present invention, the imaging optical axis of the imaging lens is formed in parallel with the normal direction of one surface of the substrate on which the target object is disposed, thereby preventing the imaging shape of the target object formed by the camera from inclining, thereby making the target object more accurate. To obtain an image.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and that one or more other features It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, actions, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted as ideal or overly formal in meaning unless explicitly defined in the present application Do not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

≪ Example 1 >

1 is a cross-sectional view showing an imaging optical system according to a first embodiment of the present invention.

Referring to FIG. 1, the imaging optical system according to the present exemplary embodiment is a system for imaging an image of the target object 20 disposed on one surface of the base substrate 10. At this time, one surface of the base substrate 10 is preferably a flat plane as a whole.

The target object 20 may be a surface-mount device (SMD) mounted on one surface of the base substrate 10. That is, the target object 20 may be disposed on one surface of the base substrate 10 to be electrically connected to a pad formed on one surface of the base substrate 10.

The imaging optical system according to the present embodiment includes an illumination unit 100, an imaging lens 200, and a camera 300.

The illumination unit 100 is disposed on the base substrate 10 to provide light to the target object 20. The imaging lens 200 is disposed on the base substrate 10 to project the reflected light reflected from the target object 20 to provide it to the camera 300. The camera 300 is disposed above the imaging lens 200 to capture an image of the target object 20 using the reflected light applied through the imaging lens 200.

In the present exemplary embodiment, the imaging lens 200 and the camera unit 300 have a central axis 22 passing through the center of the target object 20 in parallel with the normal direction 12 of one surface of the base substrate 10. It is arranged on one side based on). On the other hand, the lighting unit 100 is disposed on the other side opposite to the one side with respect to the central axis (22). Therefore, the reflected light generated by the illumination unit 100 and reflected by the target object 20 may be applied to the camera 300 by projecting the imaging lens 200.

The imaging lens 200 has an imaging optical axis 210 parallel to the normal direction 12 of one surface of the base substrate 10. That is, when the imaging vertical axis 220 of the imaging lens 200 is orthogonal to the imaging optical axis 210, the imaging lens 200 has the imaging vertical axis 220 at one surface of the base substrate 10. Arranged in parallel.

In the present embodiment, the target object 20 is disposed on one side with respect to the imaging optical axis 210, and the camera 300 is disposed on the other side opposite to the one side with respect to the imaging optical axis 210. .

Meanwhile, the camera 300 includes an imaging device 310 that receives the reflected light transmitted through the imaging lens 210 and captures an image of the target object 20. For example, the reflected light transmitted through the imaging lens 210 is applied to the imaging device 310 to form a planar image of the target object 20 on the imaging device 310, and the imaging The device 310 captures a planar image of the target object 20 and stores it in a memory (not shown) in the camera 300.

The horizontal axis of the imaging device 310 is preferably perpendicular to the normal direction 12 of one surface of the base substrate 10. That is, the horizontal axis of the imaging device 310 may be substantially parallel to the imaging vertical axis 220 of the imaging lens 200.

FIG. 2 is a cross-sectional view illustrating a relationship between a target object and an image pickup device in the imaging optical system of FIG. 1.

1 and 2, the relationship between the target object 20, the imaging lens 200, and the imaging device 310 may have the following characteristics.

The center line CL connecting the center of the target object 20, the center of the imaging lens 200, and the center of the imaging device 310 is predetermined with respect to the central axis 22 or the imaging optical axis 210. Tilted at an angle of In this case, an angle between the center line CL and the imaging optical axis 210 is defined as a center angle θ.

A vertical distance between the imaging lens 200 and the target object 20 is called a first vertical distance S1, and a vertical distance between the imaging lens 200 and the imaging device 310 is a second vertical distance. The horizontal distance between the center of the target object 20 and the imaging optical axis 210 is referred to as a first horizontal distance a, and the center of the imaging device 310 and the imaging optical axis 210 are referred to as (S2). The horizontal distance between the () is defined as the second horizontal distance (b).

Meanwhile, when the focal length of the imaging lens 200 is f, the relationship between the first and second vertical distances S1 and S2 satisfies Equation (1).

Equation (1): 1 / S1 + 1 / S2 = 1 / f

Further, the relationship between the first and second horizontal distances a and b and the center angle θ satisfies Equation (2).

Equation (2): a = S1 tanθ, b = S2 tanθ

That is, in the present embodiment, the target object 20, the imaging lens 200, and the imaging device 310 are disposed to satisfy the equation (1) and the equation (2).

On the other hand, the target object 20 should be disposed within the maximum viewing angle range of the imaging lens 200. In this case, the maximum viewing angle of the imaging lens 200 is the imaging optical axis that the reflected light reflected from the target object 20 is moved to the imaging lens 200 to form an image on the imaging device 310 ( 210) means the maximum angle. In this case, the maximum viewing angle of the imaging lens 200 may be, for example, about 35 degrees.

Therefore, when the line connecting the end of the target object 20 from the imaging optical axis 210 and the center of the imaging lens 200 is called the maximum outline of the target object 20, the imaging optical axis 210 is used. ) And the maximum outline should be smaller than the maximum viewing angle of the imaging lens 200.

As described above, the imaging lens 200 is disposed such that the imaging optical axis 210 is parallel to the normal direction 12 of one surface of the base substrate 10 supporting the target object 20. The imaging device 310 is disposed such that a horizontal axis of the imaging device 310 is parallel to one surface of the base substrate 10. In addition, the target object 20 and the imaging device 310 are disposed on both sides of the imaging optical axis 210, respectively.

Therefore, when the reflected light reflected from the target object 20 is transmitted to the imaging lens 200 and applied to the imaging device 310 to form a planar image of the target object 20, the target The planar image of the object 20 may be substantially the same as the actual planar shape of the target object 20.

<Example 2>

3 is a cross-sectional view showing an imaging optical system according to a second embodiment of the present invention.

The imaging optical system according to the present embodiment further includes the projection lens 400, the grating unit 500, and the grating transfer unit 600, and the imaging according to the first embodiment described with reference to FIGS. 1 and 2. Since the optical system is substantially the same, detailed description of other components except for the above components will be omitted, and the same reference numerals will be given to the same components as those in the first embodiment.

Referring to FIG. 3, the imaging optical system according to the present embodiment further includes a projection lens 400, a grating unit 500, and a grating transfer unit 600.

The projection lens 400 is disposed between the target object 20 and the illumination unit 100 to project the light generated by the illumination unit 100 to the target object 400.

The projection optical axis 410 of the projection lens 400 may be parallel to the normal direction 12 of one surface of the base substrate 10. That is, the projection lens 400 may be disposed such that the projection vertical axis 420 of the projection lens 400 perpendicular to the projection optical axis 410 is parallel to one surface of the base substrate 10. In the present exemplary embodiment, the imaging lens 200 and the projection lens 400 may be disposed at symmetrical positions with respect to the central axis 22.

The grating unit 500 is disposed between the projection lens 400 and the illumination unit 100 to change the light generated by the illumination unit 100 into a grid image light and provide it to the projection lens 400. In addition, the grating image light passes through the projection lens 400 and is irradiated to the target object 20. Here, the grating unit 500 may be formed in various forms. For example, the grating unit 500 may be formed by patterning a grating pattern having a blocking part and a transmitting part on a glass substrate, or may be formed using a liquid crystal display panel.

In the present exemplary embodiment, the imaging device 310 and the grating unit 500 may be disposed at symmetrical positions with respect to the central axis 600.

The grid transfer unit 600 may be combined with the grid unit 500 to move the grid unit 500. In this case, the grid transfer unit 600 may move the grid unit 500 at regular intervals in a direction parallel to one surface of the base substrate 10. The grid transfer unit 600 may include an actuator for finely moving the grid unit 500.

On the other hand, when the illumination unit 100 provides light to the grating unit 500 that is moved at predetermined intervals, a plurality of grating image light may be generated. When the grating image lights are irradiated to the target object 20 through the projection lens 400 and reflected, and the image is captured by the camera 300, the camera 300 uses the grating image lights to target the target image 20. The three-dimensional shape of the object 20 can be measured.

As such, according to the present exemplary embodiment, the imaging optical system further includes the projection lens 400, the grating unit 500, and the grating transfer unit 600. Almost similarly, the three-dimensional shape of the target object 20 can be captured.

While the present invention has been described in connection with what is presently considered to be practical and exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the above description and the drawings below should be construed as illustrating the present invention, not limiting the technical spirit of the present invention.

1 is a cross-sectional view showing an imaging optical system according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a relationship between a target object and an image pickup device in the imaging optical system of FIG. 1.

3 is a cross-sectional view showing an imaging optical system according to a second embodiment of the present invention.

   <Short Description of Main Drawing Numbers>

10: base substrate 20: target object

22: central axis 100: lighting unit

200: imaging lens 210: imaging optical axis

220: Image forming vertical axis 300: Camera

310: image pickup device 400: projection lens

410: projection optical axis 420: projection vertical axis

500: grid unit 600: grid transfer unit

Claims (10)

An imaging optical system for imaging an image of a target object disposed on one surface of a substrate, An illumination unit providing light to the target object; An imaging lens having an imaging optical axis parallel to a normal direction of one surface of the substrate; And A camera for receiving the reflected light reflected from the target object through the imaging lens to capture an image of the target object, The target object is disposed on one side with respect to the imaging optical axis, the camera is an imaging optical system, characterized in that disposed on the other side opposite to the one side with respect to the imaging optical axis. The method of claim 1, wherein the camera And an image pickup device configured to capture the planar image of the target object by receiving the reflected light transmitted through the imaging lens. And the horizontal axis of the imaging device is perpendicular to the normal direction of one surface of the substrate. The method of claim 2, wherein the imaging lens and the camera unit It is disposed on one side with respect to the central axis passing through the center of the target object in parallel with the normal direction of one surface of the substrate, The lighting unit An imaging optical system, characterized in that disposed on the other side opposite to the one side with respect to the central axis. The imaging optical system of claim 3, further comprising a projection lens disposed between the target object and the illumination unit to project light generated by the illumination unit to the target object. The projection optical axis of claim 4, wherein the projection optical axis of the projection lens An imaging optical system, characterized in that parallel to the normal direction of one surface of the substrate. The method of claim 5, wherein the imaging lens and the projection lens And an imaging optical system arranged at positions symmetrical with respect to the central axis. The optical imaging apparatus of claim 4, further comprising: a grating unit disposed between the projection lens and the illumination unit to change the light generated by the illumination unit into grating image light and to provide the grating image light to the projection lens. system. The method of claim 7, wherein the imaging device and the grating unit And an imaging optical system arranged at positions symmetrical with respect to the central axis. The imaging optical system according to claim 7, further comprising a grating transfer unit coupled to the grating unit to move the grating unit. The method of claim 1, wherein the target object An imaging optical system, characterized in that it is a surface-mount device (SMD) mounted on one surface of the substrate.

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