JPS6248556B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for determining the front and back sides of parts to be transferred.

This type of discrimination method includes, for example, Fig. 1, 2A
There is a method shown in Fig. and Fig. 2B. In the figure, an analyzer 1 is disposed above a component transfer path 2, and a light beam from its light emitting element 1a is projected onto a component 3 being transferred directly below. The transfer path 2 is, for example, a track of a vibrating component feeder, and the vibrations cause the component 3 to be transferred to the left in FIG. 1, as indicated by arrow a. The illustrated component 3 is a resistance element used in a variable resistance device, and is a brown Bakelite plate 3.
Ω-shaped tin plating 3b is applied to the surface of a.
Therefore, in this component 3, the tin-plated portion 3b is a light-reflecting portion, and the other Bakelite portion 3a is a non-light-reflecting portion. The analyzer 1 is disposed directly above the line C-C, and when the front-facing component 3 passes below the analyzer 1 as shown in FIG. 2A, the light projected onto the tin plated portion 3b is reflected. The light then reaches the photosensitive element 1b of the analyzer 1, whereby the analyzer 1 detects that the component 3 located below it is facing up. Furthermore, when the component 3 is transferred face down below the analyzer 1 as shown in FIG. 2B, the light beam from the light emitting element 1a is projected onto the component 3, but most of it is reflected. No, photosensitive element 1
b receives almost no reflected light. Thereby, the analyzer 1 detects that the component 1 below it is face down.

Note that the transfer path 2 itself has a certain degree of light reflection depending on its surface properties, but it is sufficient to make it distinguishable from the reflectance of the component 3, and in some cases, the surface of the transfer path 2 may be painted black. Alternatively, you can create a recess. Alternatively, the fact that the component 3 has come directly below the analyzer 1 may be detected by some method, thereby enabling the analyzer 1 to operate. There are various known means for these.

However, as described above, it is only necessary to be able to distinguish between the front and back sides of the component 3, but in reality, even if the component 3 is face down, light may be reflected at the edge of the component 3 and projected onto the photosensitive element 1b. , or may be reflected by scratches on the surface of parts. Furthermore, due to the inclination of the component 3, light may be reflected from a non-reflective portion or reflected light from a reflective portion may not be projected onto the photosensitive element 1b.
In such a case, the front and back sides of the component 3 will be incorrectly determined.

The analysis output of the analyzer 1 is as shown by arrow b.
The parts are supplied to the parts removing means or the front and back correcting means, but if the front and back sides are incorrectly determined, the parts to be removed may be fed as they are to the next process or may be erroneously corrected. As a result, the efficiency of supplying parts in desired orientations is reduced.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a method for determining the front and back sides of transferred parts, which can always accurately determine the front and back sides of parts. According to the present invention, this object is achieved by disposing a light analyzer for receiving reflected light from a light reflecting portion of a component above a component transfer path, and with the surface of the component facing upward, a light analyzer is provided below the light analyzer. A histogram of the number of times the light is received by the analyzer when the part passes through the analyzer, and the number of times the analyzer receives the light when the part passes under the analyzer with the back side facing upward. A threshold value for the number of times the analyzer receives light reflected from the reflective parts of the front and back parts is determined, and the number of times the light is received is determined from this threshold value. This is achieved by a method for determining the front and back sides of parts to be transported, which is characterized in that the front and back sides of parts are determined based on whether they are large or small.

Embodiments of the present invention will be described below with reference to the drawings. Note that although FIG. 3 and subsequent figures show embodiments of the present invention, parts corresponding to those in FIGS. 1 to 2B are given the same reference numerals.

FIG. 3 shows a first embodiment of the present invention. In this embodiment, the analyzer 1 is disposed directly above the line D-D which is offset laterally from the center line C-C of the transfer path 2. be done. Therefore, ideally, when the front-facing component 3 passes below the analyzer 1, the photosensitive element 1b should receive reflected light from the three locations X, Y, and Z of the tin-plated portion 3b. . Furthermore, the component 3 facing down should not receive reflected light even once.

However, in reality, due to the reasons mentioned above, 100%
3 times for face-up part 3, 3 times for face-down part 3
There is no guarantee that the light will be received zero times. Therefore, according to the present invention, the number of times of light reception and detection by the analyzer 1 is actually tested for a large number of face-up and face-down parts 3, and a histogram is created for each of them. FIG. 4 is an example of this. In the figure, the hatched bar graphs are for parts 3 that are facing down, and the bar graphs that are not hatched are for parts 3 that are facing up. Part 3 face down as expected
For most of them, the number of times of light reception and detection is 0 times, and for most of the parts 3 facing upward, the number of times of light reception and detection is 3 times. The respective numbers are also observed for 1st, 2nd, and 4th times, but it is understood that 2 times is the threshold for heads or tails. Also, although the difference is slight, the number of times of light reception and detection twice is higher for the face-up component 3, so that twice or more is determined to be face-up, and once or less is determined to be face-down. Therefore, if the detection device 1 receives and outputs light twice or more for one component, it is determined that the component is facing up, and if it is less than once, it is determined that the component is facing down.

Regarding the creation of a histogram as shown in Fig. 4, it is also possible to actually flow, for example, 100 face-up parts 3 and 100 face-down parts 3 and count the number of parts for each number of light reception detections. , a large number of parts 3 may be passed completely randomly from front to back, the number of light reception detections for each part 3 may be supplied to a computer, the number of light reception detection times - number of parts may be calculated, and the threshold value may be determined based on the result. . In this case, the present invention can be completely automated by supplying the threshold output of this computer to a discrimination circuit connected to the analyzer 1.

FIG. 5 shows a second embodiment of the present invention, and according to this embodiment, there is a Another analyzer is provided. In this case, the total number of light reception and detection by both analyzers is zero for the front-facing component 3, and the maximum number for the front-facing component 3 is six times, but the threshold value is more accurately determined.
It will be understood that the discrimination ability is further improved than in the first embodiment.

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiments, the components shown in FIGS. 2A and 2B have been described, but the present invention is also applicable to other components that have optical differences between the front and back sides. Further, the parts may not be plate-shaped as shown in the figure, but may be block-shaped.

As described above, according to the method of the present invention, the number of light reception detections or response times of a reflective analyzer is statistically determined for each of a large number of front and back parts, and the threshold number of times for distinguishing front and back parts is determined from this. However, since the front and back of the component is determined based on whether the number of responses of the analyzer is greater or less than this number, it is possible to determine the front and back of the component with high accuracy in practice.

[Brief explanation of the drawing]

Fig. 1 is a schematic side sectional view of a conventional device for determining front and back sides of parts, Fig. 2A is a plan view taken in the - line direction in Fig. 1 to show the relationship between the front side parts and the analyzer, and Fig. 2B. 2A is a plan view similar to that shown in FIG. 2A for showing the same relationship for the face-down parts; FIG. 3 is a plan view similar to FIG. 2A in the first embodiment of the present invention; and FIG. 4 illustrates the same embodiment. graph for,
and FIG. 5 is the second A in the second embodiment of the present invention.
It is a top view similar to the figure. In the figure, 1...analyzer, 1a...light emitting element, 1b...photosensitive element, 2...transport path, 3...
...Parts, 3a...Bakelite board, 3b...Tin plating part.

Claims (1)

[Claims] 1. An analyzer for receiving reflected light from a light reflecting portion of a component is disposed above the component transfer path, and the light obtained when the component passes below the analyzer with the surface facing upward. A histogram of the number of light receptions by the analyzer and the number of light reception by the analyzer obtained when the component passes below the analyzer with its back side facing upward is calculated for a large number of front-facing and back-facing parts. Create a threshold value in advance for the number of times the analyzer receives light reflected from the reflective parts of front-side and back-side parts. A method for determining front and back sides of parts to be transferred, characterized in that the front and back sides of transferred parts are determined.