JPS62140917A - Article position detecting device in article conveying system - Google Patents

Abstract

PURPOSE:To make it possible to detect several positions with the use of a small number of detectors, by providing a light source and a light-conductive receiving section at each detecting position, and by connecting the other end of light conductive members to light detectors having a number less than the number of the detecting numbers in such a way that each adjacent conductive members are not connected to one and the same light detector. CONSTITUTION:When there is no sheet material at detecting positions A through E, light beams from light sources 13a through 13e are absorbed by a conveyer 10, and therefore, only a slight amount of light reaches detectors 15A through 15B through optical fibers 14a through 14e. Meanwhile at the detecting positions A through E where a sheet material 11 reaches, the amount of light passing through the optical fibers 14a through 14e corresponding to the positions increases. Accordingly, the light detector 15a detects an increased amount of light when the sheet material 11 extends along the positions A, C, E while the light detector 15B detects an increased amount of light when the sheet material 11 extends along the positions B. D. Such variations in light amount are processed by a signal processing circuit 17 after being amplified by amplifiers 16A, 16B, and therefore, a position detection signal is obtained. With this arrangement it is possible to detect several positions with the use of a small number of detectors.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a device for detecting the position of an article conveyed by an article conveyance system, and more particularly, the present invention relates to an apparatus for detecting the position of an article conveyed by an article conveyance system, and more particularly, to an apparatus for detecting the position of an article at a large number of positions using a small number of photodetectors. This article relates to a device that enables this.

(Technical Background and Prior Art of the Invention) For example, in devices that record images on a recording medium while conveying the recording medium within the device, or in assembly lines for various products, in many cases, the recording medium is conveyed by a conveyance system. It is necessary to detect the position of the item. Conventionally, devices for detecting the position of articles have been constructed by combining a light source that emits light toward the article at a predetermined detection position along the conveyance system, and a photodetector that detects this light. Widely used. In other words, if the light reflected from the above-mentioned article is detected by a photodetector, it can be determined that the article has passed the detection position when the photodetector outputs a photodetection signal. If the light emitted toward the object is blocked by the object being transported, it can be determined that the object has passed the detection position when the light detection signal output from the photodetector is interrupted.

However, in the conventional apparatus described above, a photodetector is provided at each detection position, so there is a problem in that the cost of the apparatus becomes extremely high when a large number of article detection positions are set.

(Object of the Invention) Therefore, an object of the present invention is to provide an article position detection device in an article conveyance system that can detect article positions at a large number of positions using a small number of photodetectors. .

(Structure of the Invention) The article position detection device for an article conveyance system of the present invention is applied when detecting article positions at three or more detection positions along a conveyance system that conveys articles along a fixed route. Yes, the light emitted from the light source and indicating the presence or absence of an article is not directly detected by the photodetector, but is guided to the photodetector by a light transmission means consisting of a plurality of light guides provided corresponding to each detection position. In addition, the number of photodetectors is smaller than the number of detection positions, that is, the number of light guides (two or more), so that naturally at least one photodetector can be coupled to a plurality of light guides. However, the light guides from adjacent detection positions are coupled to different photodetectors, and each photodetector receives a signal indicating that an article is present at one of the detection positions. , the article position is detected by a signal processing circuit that specifies the detection position in response to switching of the photodetector that outputs this signal.

(Embodiment g, Hammer) Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.

FIG. 1 shows a 16-piece placement detection device in an article conveyance system according to a first embodiment of the present invention.

Actual implementation! As an example, the shaking device includes bell 1 to conveyor 10.
It is formed so as to detect the position of the sheet material 11 placed thereon and conveyed in the X direction. Note that the belt conveyor 10 is not reversed and the sheet material 1
1 is always conveyed in the direction of the arrow X above. In this example,
The sheet material 11 is detected at five detection positions A, B, C, D, and E along the belt conveyor 10. That is, each detector HA, 8. At C, D and E, light is directed onto the belt conveyor 10, respectively. 2a, 12b.

Light ff113 emitting 12G, 12d and 12e
a, 13b, 13c, 13d and 13e are provided, and optical fibers 14a, 14b as light guides,
One ends of 14c, 14d and 14e are arranged.

These optical fibers 14a to 14e transmit the light beams 12a to 14e.
12e to photodetectors 15A and 153, which will be described later, and one end of each is connected to the bell 1 to the conveyor 10 (or when the sheet material 11 is conveyed). It is arranged at a position where each of the above-mentioned lights 12a to 12e reflected (on the material 11) is incident.

The other ends of the five optical fibers 14a to 14e are connected to two photodetectors 15A made of, for example, photodiodes,
153. Here, the optical fibers 14a, 14C, and 14e connect to one photodetector 15A.
and optical fibers 14b, 14d are coupled to a used photodetector 15B. In other words, the optical fibers whose one ends are arranged at adjacent detection positions are coupled to different photodetectors. Each detection position A, B, C
, D or E light 12a112b, 12c, 1
2d or 12e is the sheet material 11 at its detection position.
When it is not present, a large amount is absorbed on the surface of the belt conveyor 10. Therefore, in this case, the optical fiber 14a
A relatively small amount of light is transmitted via 114b, 14c, 14d or 148 to photodetector 15A1 or 15B. On the other hand, when the sheet material 11 is sent to each detection position A, B, C, D or E, the light 12a, 12
b, 12c, 12d or 12e is reflected in a large amount on this sheet material 11, so the photodetector 15A or 12e is
A relatively large amount of light is transmitted to 53. In other words, when the sheet material 11 is present at the detection position A, C, or E, the photodetector 15A outputs an H (Hiah level) signal indicating a large amount of detected light; otherwise, the photodetector 15A outputs the An L (LOW level) signal indicating a small amount of light is output. In addition, when the sheet material 11 is present at the detection position B or D, H
At other times, the photodetector 15B outputs an L signal indicating that the detected light is small.

The H signal or low signal output from the photodetectors 15A and 15B as described above is transmitted to the amplifiers 16A and 1, respectively.
6B and input to the signal processing circuit 17. This signal processing circuit 17 is configured such that when the sheet material 11 is conveyed as described above, the H signal indicating that the sheet material 11 is present at each detection position is alternately switched from the photodetector 15A and the photodetector 15B. Using this input, it is specified where the sheet material 11 is located among the five detection positions A to E. That is, the photodetectors 15A, 15
The signal input from B to the signal processing circuit 17 is switched as shown in the table below depending on the position where the sheet material 11 is detected (in this table, the H signal is changed to the 01L signal and the
).

While the sheet material 11 has not yet been sent to the detection position A, L signals are input to the signal processing circuit 17 from both the photodetectors 15A and 15B. As mentioned above, the sheet material 11
Since the sheet material 11 is transported only in the direction of the arrow X, when the H signal is input from the photodetector 15A to the signal processing circuit 17, the signal processing circuit 17 determines that the sheet material 11 has been sent to the detection position A. , a position detection signal S indicating that the sheet material 11 is at the detection position A while the H signal is being input.
Output. When the sheet material 11 passes the detection position A, the signal processing circuit 17 again includes both photodetectors 15A and 15.
An L signal is input from B to both. Next, the photodetector 15
When the H signal is input from B, the signal processing circuit 17 determines that the sheet material 11 has been sent to the detection position B, and outputs a position detection signal S indicating this fact. Similarly, H
In response to the switching of the signal, the sheet material 11 moves to the detection position c,
, o, E is detected.

Note that the signal processing circuit 17 can be constructed from, for example, a known logic circuit.

Next, a second embodiment of the present invention will be described with reference to FIG. Note that in FIG. 2, elements that are equivalent to those in FIG. 1 are given the same numbers, and explanations thereof will be omitted. In this device, one light source 13
A plurality of (-5 as an example) optical fibers 30a, 3
One ends of 0b, 30c, 30d, and 30e are connected. Their other ends are at detection positions A-E, respectively.
Optical fibers 148 to 14e similar to those described above are arranged so that the lights 12a to 12e emitted from the other ends of these optical fibers 30a to 30e are incident.

Note that the optical fibers 30a to 30e are connected to the belt conveyor 10.
When the article 40 conveyed by the detectors arrives at each of the detectors @A-E, the light beams 12a to 12e are respectively placed in positions such that they are blocked by the article 40. Therefore, in this case, the H1L signals input from the photodetectors 15A and 153 to the signal processing circuit 17 are switched as shown in the table below depending on the position of the article 40 (Same as above, the H signal is O, the L signal is ).

When the article 40 is not located at any of the detection positions A to E, an H signal is input to the signal processing circuit 17 from both photodetectors 15A and 15B.

In this case as well, the signal processing circuit 17 sequentially processes the article 40 in response to switching of the photodetectors 15A and 15B that output the L signal.
is sent to the detection position ~E.

Note that the number of detected positions of articles is determined by the first and second points explained above.
The number of locations is not limited to five in the embodiment, and may be any number of locations, including three or more.

In addition, in the device of the present invention, basically two photodetectors may be provided, but in order to avoid the light guide from becoming extremely long, three or more photodetectors (a number smaller than the number of detection positions described above) may be installed. ) may be provided.

(Effects of the Invention) As explained in detail above, the article position detection device in the article conveyance system of the present invention has a minimum of 2 detection positions no matter how large the number of detection positions is.
It is possible to detect the position of an article by using just one photodetector, and therefore the device of the present invention can be made extremely inexpensive and compact compared to conventional devices in which a photodetector is installed at each detection position.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing a device according to a first embodiment of the present invention, and FIG. 2 is a schematic plan view showing a device according to a second embodiment of the present invention. 10... Belt conveyor 11... Sheet material 1
2a~12e...light 13.13a~13e・
...Light sources 14a to 14e, 30a to 30e...Optical fibers 15A, 15B...Photodetector 17...
Signal processing circuit 20... optical transmission means 40...
Article A-E...Detection position

Claims (1)

[Scope of Claims] A device for detecting the position of an article conveyed along a certain route by an article conveyance system, comprising: emitting light toward the article at three or more detection positions along the conveyance system; a light source for irradiation; a plurality of photodetectors smaller in number than the number of detection positions; one end arranged to receive light indicating the presence or absence of the article at the detection position, and the other end coupled to the photodetector; ,
The light guides are composed of the same number of light guides as the detection positions, and the light guides whose one ends are arranged at the detection positions adjacent to each other are light transmitting means whose other ends are coupled to different photodetectors. , a signal processing circuit that receives a signal from the plurality of photodetectors indicating that the article is at one of the detection positions, and specifies the detection position according to switching of the photodetector that outputs the signal; An article position detection device in an article conveyance system, comprising: