JPH1068614A - Image pickup system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup system in which the size is reduced, the inspection time is shortened and the cost is reduced. SOLUTION: The image pickup system 1 comprises an illumination system 3 having an LED 9 for illuminating an object 6 arranged in a region S to be read out, a system 4 for picking up the image of the object 6 by receiving the light from the illumination system 3 reflected on the object 6, and a lens system 5 interposed between the image pickup system 4 and the illumination system 3 in order to focus the reflected light on the image pickup system 4. The lens system 5 comprises a single focus lens system 12 while the image pickup system 4 comprises a single image pickup means 13. A side face observation mirror 8 is arranged oppositely to at least one side face 6a of the object 6 arranged in the region S to be read out. Reflected light from the side face observation mirror 8 is directed directly to a focus lens means 12 the image of at least one side face 6a of the object 6 is picked up by the image pickup means 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device,
In particular, the present invention relates to an imaging device used for side observation of a lead in a process of mounting an electronic component on a circuit board.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 6-216580 discloses an example of a conventional imaging apparatus. In the device disclosed in this publication, when an electronic component such as a QFP or an SOP is mounted on a circuit board, a lead (outer lead) of the electronic component sucked by a nozzle is directly taken by one camera. It is configured to be observed. Therefore, the bent state of the lead extending from the side surface of the package can be observed optically and in a non-contact state with a camera arranged on the side,
It is possible to inspect the ups and downs (coplanarity) of the leads and the like, and to perform a preliminary measurement for mounting the components on the circuit board, and it is possible to preliminarily select the defective components with the raised leads.

[0003]

However, since the conventional imaging apparatus is configured as described above, there are the following problems. That is, since the lead of the electronic component is inspected from the side by one camera arranged on the side, a flow step of sequentially imaging each side surface of the electronic component while rotating the nozzle by 90 degrees is required. In addition, it takes time to inspect leads of electronic components. Further, when inspecting the four side surfaces of the electronic component at the same time, four cameras must be arranged around the electronic component, so that there is a problem that the image pickup apparatus becomes large.

[0004] The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an image pickup apparatus capable of reducing the size, the inspection time, and the cost.

[0005]

According to a first aspect of the present invention, there is provided an image pickup apparatus comprising: an illumination system having a light source for illuminating an object to be read disposed in a reading area with illumination light; and an illumination system. An imaging system that receives reflected light from the object to be read and captures an image of the object to be read, and a lens system that is arranged between the imaging system and the illumination system and forms an image of the reflected light on the imaging system. In the imaging apparatus having the above, the lens system is constituted by one imaging lens unit, the imaging system is constituted by one imaging unit, and a side surface observation mirror is provided at a position facing at least one side surface of a reading object arranged in a reading area. Is disposed, the reflected light from the side-viewing mirror is directly incident on the imaging lens means, and the image pickup means captures an image of at least one side of the object to be read.

[0006] In this imaging apparatus, a reading object arranged in a reading area is illuminated by illumination light emitted from an illumination system. At this time, the reflected light from the side surface of the object to be read is reflected by a side surface observation mirror provided at a position facing the side surface of the object to be read, and then directly reaches the imaging lens unit. The light that has passed through the imaging lens means
The image is taken as an image of the side surface of the object to be read by the imaging means.
Therefore, according to the fixed magnification of the imaging lens means, the optical path length between the side-viewing mirror and the imaging lens means can be easily changed only by changing the reflection angle of the side-viewing mirror. In particular, since the imaging device of the present invention is reduced in size, it is effective when the installation space in the electronic component mounting device is limited in consideration of other mechanisms.

In this case, it is preferable that the side-viewing mirror face two sides of the object to be read disposed in the reading area, and that the imaging means simultaneously capture images of the two sides of the object to be read. When such a configuration is adopted, images of two sides of the object to be read that have passed through one imaging lens unit can be simultaneously imaged by one imaging unit, so that simultaneous observation of the two sides of the object to be read is possible. And the amount of ups and downs of the leads extending from the two sides of the object to be read can be inspected at one time. Further, even for an electronic component of a type in which leads are arranged on four sides of an object to be read, the ups and downs of all the leads can be inspected only by rotating by 90 degrees. Accordingly, the efficiency of lead inspection can be increased.

It is preferable that the side-viewing mirrors face the four sides of the object to be read arranged in the reading area, and that the imaging means simultaneously captures images of the four sides of the object to be read. When such a configuration is adopted, images of four sides of the object to be read that have passed through one imaging lens unit can be simultaneously imaged by one imaging unit, so that simultaneous observation of the four sides of the object to be read is possible. Becomes possible. Therefore, the amount of ups and downs of the leads arranged on the four sides of the object to be read can be inspected at a time, and the inspection speed of the leads is dramatically improved.

Further, it is preferable that the reflected light from the side observation mirror and the reflected light from the bottom surface of the object to be read are directly incident on the imaging lens means, and the images of the side surface and the bottom surface of the object to be read are simultaneously taken by the imaging means. When such a configuration is adopted, the image of the bottom surface of the object to be read can be simultaneously imaged by the imaging means, and the displacement and posture of the object to be read with respect to the suction nozzle can also be imaged. It will be more certain.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an imaging apparatus according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view showing an image pickup apparatus according to this embodiment. The imaging apparatus 1 shown in FIG. 1 includes a casing 2 forming a dark box.
An illumination system 3 is arranged at an upper part, an imaging system 4 is arranged at a lower part, and a lens system 5 is arranged between the illumination system 3 and the imaging system 4. The image pickup apparatus 1 picks up an image of an electronic component (surface mount device) having a package developed in response to demands for downsizing, thinning, and multifunctional electronic components, and is incorporated as a part of an electronic component mounting device (not shown). Have been. Packages include QFP, SOP, SOJ, QFJ, and the like.

As shown in FIGS. 1 and 2, at the top of the image pickup apparatus 1, there is provided a reading area S for disposing a packaged electronic component 6 as an object to be read. This is an area where the electronic component 6 being transported from the component stocking location to a circuit board (not shown) using the suction nozzle 7 is temporarily taken in for component inspection. Four side-viewing mirrors 8 composed of total reflection type mirrors are arranged on four sides of the reading area S. Each side-viewing mirror 8 is disposed with a phase angle of 90 degrees in the horizontal direction around the reading area S, and is fixed to the inner wall surface of the casing 2 with a predetermined reflection angle α. Further, each side surface observation mirror 8 faces each side surface 6a of the electronic component 6 in the reading area S in a one-to-one manner in the horizontal direction, and obliquely collects the reflected light from each side surface 6a to the lens system 5. Pointed downward.

An illumination system 3 is arranged below the reading area S. The illumination system 3 has a light source 9 for illuminating each side surface 6a and bottom surface 6b of the electronic component 6 from obliquely below.
The light source 9 is arranged as a row of LEDs on an annular mounting base 10, which is fixed to the casing 2, and in the center of the mounting base 10 is a bottom surface connecting the bottom surface 6 b of the electronic component 6 and the lens system 5. In order to secure an optical path for the image, an opening 11 is formed to allow the reflected light from the bottom surface 6b of the electronic component 6 to pass toward the lens system 5. Also, the mounting table 10
Needs to be arranged below the side-viewing mirror 8 so as to avoid the side-view image optical path connecting the side-viewing mirror 8 and the lens system 5. This is because the light reflected by the side surface observation mirror 8 is directly incident on the lens system 5.

The lens system 5 comprises a single imaging lens means 12 and is of a fixed focus type and has a desired focal length. Immediately below the reading area S, the imaging lens means 12 is located at the center axis. It is arranged concentrically with respect to it.
The imaging lens means 12 has such a wide angle that the reflected light from each side-viewing mirror 8 can be taken in from all directions, and can capture the bottom and side images of the electronic component 6 at the same time. It has a depth of field.

The imaging system 4 includes one CCD (imaging means) 13
The CCD 13 is disposed at the focal position of the imaging lens means 12 and is disposed directly below the imaging lens means 12 and concentrically with respect to the central axis. Therefore, a side image and a bottom image of the electronic component 6 having passed through the imaging lens means 12 can be simultaneously captured by the CCD 13.

Next, a description will be given of the operation when the image pickup apparatus 1 picks up an image of the QFP type electronic component 6 in which a plurality of leads L are arranged on the four side surfaces 6a.

First, the electronic component 6 sucked in vacuum by the suction nozzle 7 of the electronic component mounting apparatus (not shown) and transported from a predetermined place is arranged in the reading area S of the image pickup apparatus 1. Then, the side surface 6a and the bottom surface 6b of the electronic component 6 are illuminated by turning on the light source 9 made of an LED. At this time, each of the leads L arranged on each side surface 6a is illuminated, and at the same time, the light reflected by each lead L enters each of the four side surface observation mirrors 8 and the light reflected by each side surface mirror 8 is combined. The light is focused on the image lens means 12. Also, since the bottom surface 6b of the electronic component 6 is a horizontal flat surface,
The light reflected by the bottom surface 6b is reflected immediately below and, at the same time, passes through the opening 11 of the mounting table 10, and then forms the imaging lens means 1.
2 is incident.

The light transmitted through the imaging lens means 12 is incident on the CCD 13, and as shown in FIG.
Now, four side images 14 and one bottom image 1 of the electronic component 6
5 are imaged simultaneously. In this case, the bottom image 15 is a CCD
An image is picked up at the center of 13, and each side image 14 is imaged in a mirror-symmetrical state on four sides. The side image 14 picked up by the CCD 13 is sent to an image processing device (not shown) as data, and is used for inspection of the amount of ups and downs in each lead L and chucking of the suction posture by the suction nozzle 7. Further, the bottom image 15 picked up by the CCD 13 is also sent as data to the image processing device, and is used as an inspection for a positional shift and a suction posture of the electronic component 6 with respect to the suction nozzle 7. At this stage, a defective product having a poor lead arrangement and an electronic component 6 having a poor suction attitude are selected in advance. Thus, the four side images 14 of the electronic component 6
By simultaneously capturing one bottom image 15 and the other, the inspection speed and inspection accuracy of the electronic component 6 are dramatically improved.

The present invention is not limited to the above-described embodiment. For example, as shown in FIG.
In A, the reading area S is located immediately below the reading area S, that is, the reading area S
By completely closing the space between the light source 9 and the imaging lens means 12 with the mount 20 for the light source 9, as shown in FIG.
, Only the four side images 14 are imaged, and the portion of the bottom surface 6b of the electronic component 6 is hidden behind the mounting table 20 and does not appear. In the image pickup apparatus 1A shown in FIG. 4, the same or equivalent components as those of the image pickup apparatus 1 shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The SOP in which the leads L are arranged only on the two side surfaces 6a of the electronic component 6 is formed by making the two side observation mirrors 8 and making each side observation mirror 8 face the two side surfaces 6a of the electronic component 6. This is extremely effective for a type such as a package, and can further reduce the size and cost as compared with an imaging device having four side-viewing mirrors 8.

Further, the image pickup apparatus of the present invention is not limited to the image pickup of the electronic component 6, but may be used for checking the horizontality and the height level of the suction surface provided at the tip of the suction nozzle 7 as an object to be read. Is also used.

[0022]

Since the imaging apparatus according to the present invention is configured as described above, the following effects can be obtained. That is, the lens system is constituted by one imaging lens unit, the imaging system is constituted by one imaging unit, and a side surface observation mirror is arranged at a position facing at least one side surface of a reading object to be arranged in a reading area, The reflected light from the side-viewing mirror is directly incident on the imaging lens means, and the image pickup means picks up an image of at least one side of the object to be read, so that the image pickup apparatus can be downsized and the number of parts can be reduced. Thus, the cost can be reduced, and the inspection time of the object to be read can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an imaging device according to the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of the imaging device illustrated in FIG. 1;

FIG. 3 is a diagram showing an image of an electronic component obtained by the imaging device of FIG. 1;

FIG. 4 is a schematic diagram showing another embodiment of the imaging device according to the present invention.

FIG. 5 is a diagram illustrating an image of an electronic component obtained by the imaging device of FIG. 4;

[Explanation of symbols]

S: reading area, 1, 1A: imaging device, 3: illumination system, 4
... Imaging system, 5 ... Lens system, 6 ... Electronic components (read object), 6a ... Side, 6b ... Bottom surface, 7 ... Suction nozzle (Read object), 8 ... Side observation mirror, 9 ... LED (light source), 12: imaging lens means, 13: CCD (imaging means).

Claims (4)

[Claims] 1. An illumination system having a light source for illuminating an object to be read arranged in a reading area with illumination light, and receiving reflected light from the object to be read generated when the object is illuminated by the illumination system. An imaging system having an imaging system for imaging the object to be read, and a lens system arranged between the imaging system and the illumination system to form the reflected light on the imaging system. Is constituted by one imaging lens means, the imaging system is constituted by one imaging means, and a side observation mirror is arranged at a position facing at least one side of the object to be read arranged in the reading area, An imaging apparatus, wherein reflected light from a side-viewing mirror is directly incident on the imaging lens unit, and the imaging unit captures an image of at least one side surface of the object to be read. 2. The apparatus according to claim 1, wherein the side-viewing mirror faces two sides of the object to be read arranged in the reading area, and the imaging means simultaneously captures images of the two sides of the object to be read. The imaging device according to claim 1. 3. The apparatus according to claim 2, wherein the side-viewing mirror faces four sides of the object to be read arranged in the reading area, and the imaging means simultaneously captures images of the four sides of the object to be read. The imaging device according to claim 1. 4. The reflected light from the side-viewing mirror and the reflected light from the bottom surface of the object to be read are directly incident on the imaging lens means, and the image pickup means forms images of the side surface and the bottom surface of the object to be read. The imaging device according to claim 2, wherein imaging is performed simultaneously.