Television – Special applications – Manufacturing
Reexamination Certificate
1999-01-19
2002-03-19
Le, Vu (Department: 2613)
Television
Special applications
Manufacturing
C348S091000, C348S094000, C348S095000
Reexamination Certificate
active
06359646
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a part mounting device for automatically mounting electronic parts on a printed circuit board while correcting the positions of the electronic parts.
2. Description of the Related Art
Conventionally, there was a part mounting device for mounting a number of integrated circuit-type electronic parts (simply referred to as parts hereinafter) such as an IC, a resistor, a condenser, etc. on a printed circuit board (simply referred to as a board hereinafter). This part mounting device comprises a mounting head which can move upward and downward and is attached to a working tower which can move to the right and left and back and forth, picks up a part from a part supplying device with a picking-up nozzle of the mounting head, and mounts the picked up part at a mounting position on the board, which is specified by a parameter of a mounting process program.
At this time, the position of the part picked up by the picking-up nozzle (the attitude or the orientation of the picked up part) is not fixed. Therefore, the picking-up state of the part is examined, a deviation from the center of the picking-up position, the rotational state of the picking-up attitude, etc. are examined, and the position is corrected in order to correctly mount the part at the assigned position on the board based on the results of the examinations.
FIG. 1
is a side view exemplifying the configuration of such a conventional part mounting device. A part mounting device
1
shown in this figure is in a state where a mounting head
2
attached to a working tower (not shown) picks up each part
5
supplied from a part supplying unit
4
by using a picking-up nozzle
3
, moves along a moving route indicated by a broken line arrow A, and stops so that a part recognizing device can recognize an image of a picked up part in order to correctly mount the part on a board
6
.
An illuminating device
7
of the part recognizing device illuminates the part
5
from below, and an image recognizing camera
8
of the part recognizing device captures the image of the part
5
. This image information is transmitted to a controlling unit via a signal cable. The controlling unit processes the captured image of the part
5
, compares the processed image with required image data, and calculates the correction values of the position at which the mounting head
2
must stop over the board
6
and of the angle to which the picking-up nozzle
3
must rotate based on the results of the comparison.
The above described board
6
is conveyed into the part mounting device
1
along board guide rails
9
, and is supported from below with pins
13
of a support plate
12
which is raised by a raising/lowering device
11
. Its exact position is determined with a position determining pin
14
, and the board
6
is fixed to the board guide rails
9
. The mounting head
2
mounts the part
5
at the required mounting position on the fixed board
6
, and the position of the part
5
is properly determined as described above based on the calculated correction values.
To capture the image of the part
5
with the image recognizing camera
8
as described above is an essential step for performing image recognition. Especially, since the arrangement density of lead wires and bumps of a part has become high in recent years with the advances in part manufacturing techniques, the above described step for recognizing an image of a part with an image recognizing camera become more and more important in order to correctly connect the electrode-terminal of the part to the printed wiring on the board
6
, that is, to mount the part, the step of recognizing the image of a part with an image recognizing camera becomes more and more important. However, the mounting head must move to and stop at the position at which the image recognizing camera for capturing the image of a part is arranged, after it picks up the part.
Therefore, the amount of time required for moving and stoppage for each part is accumulated by the number of parts mounted on one board, and the accumulated amount of time will become of significant amount such that it cannot be ignored in a total amount of operation time. This is a principal factor which prevents an improvement of the efficiency of part mounting operations, that is, the improvement of the productivity of board units.
SUMMARY OF THE INVENTION
The present invention was developed in the above described background, and aims at providing a part mounting device for efficiently performing part mounting operations without an amount of time required for moving and stopping in order to recognize an image of a part. To achieve this aim, a working tower of the part mounting device according to the present invention comprises: an image transmitting unit which is configured by an optical waveguide composed of an optical fiber bundle intended for transmitting an image of an electronic part picked up by a picking-up nozzle, and is attached to the working tower; an image recognizing camera for capturing the image of the electronic part transmitted by the image transmitting unit; and a flexible cable for transferring the image captured by the image recognizing camera to a controlling unit. The electronic part is picked up from a part supplying device with the picking-up nozzle which can be attached/detached to/from a nozzle shaft of a mounting head of the working tower. The image of the picked up part is then captured with the image recognizing camera while the part is being moved to a mounting position, and the captured image is transferred to the controlling unit. The controlling unit recognizes the captured image, corrects the mounting position of the electronic part based on the results of the recognition, and controls the working tower in order to mount the electronic part at the proper position based on the correction values.
Additionally, this part mounting device may further comprise a part illuminating unit for illuminating the electronic part picked up by the picking-up nozzle via the optical waveguide; and an image recognizing camera which is different from the image recognizing camera
8
used in order to capture the image of the electronic part picked up by the picking-up nozzle on the route along which the working tower moves. The image transmitting unit and the illuminating unit are configured by sharing the optical waveguide, for example, via a beam splitter. The nozzle shaft is arranged, for example, by being inserted into an insertion hole arranged close to an entry point of the image transmission path of the image of the electronic part within the optical waveguide. Furthermore, the image recognizing camera is configured to also detect a mark indicating the position of the printed circuit board, which is transmitted, for example, via the optical waveguide.
REFERENCES:
patent: 5381508 (1995-01-01), Krumenacher
patent: 5541834 (1996-07-01), Tomigashi et al.
patent: 5854745 (1998-12-01), Muraoka et al.
patent: 4-31802 (1992-02-01), None
patent: 4-165309 (1992-06-01), None
patent: 5-51298 (1993-08-01), None
patent: 6-112690 (1994-04-01), None
patent: 10-145094 (1998-05-01), None
Frishauf, Holtz Goodman, Langer & Chick, P.C.
Le Vu
Yamagata Casio Co., Ltd.
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