JPS60147602A - Mark sensor - Google Patents

Abstract

PURPOSE:To detect surely marks by irradiating the light from a light source to a measuring object through a beam splitter and an object lens and leading the reflected light to a line sensor and outputting a detection signal only when a mark is detected. CONSTITUTION:A mark sensor consists of a light source 1, a lens 2, a beam splitter 3, an object lens 4 having a large diameter, a cylinder lens 7, a line sensor 8, a control line 9, and an output circuit 10. A measuring object 5 with a mark 6 is set so as to be fed at certain speed. When the light from the light source 1 is irradiated to the measuring object 5 and the mark 6 through the beam splitter 3 and the object lens 4, the reflected light is made incident on the line sensor 8 through the beam splitter 3 and the cylinder lens 7 and is processed by the output circuit 10 to detect variation of the angle of inclination of the surface of the measuring object 5, and the detection signal is outputted only when the mark 6 is detected, and thus, the mark 6 is detected surely even if the color of the measuring object 5 is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mark sensor for detecting marks provided at predetermined intervals on a measurement object such as cloth, and for cutting the measurement object such as cloth into a predetermined length. .

Conventionally, the length of cloth tape, etc. is measured using a reflective photoelectric switch placed on plastic or adhesive tape. ing. However, according to this method, it is necessary to adjust the detection level of the switch every time the light on the tape or mark changes. In particular, making adjustments such as color matching every time a lot changes is inefficient from the point of view of automation and labor saving, and neglecting to make adjustments can result in the processing line having to be stopped. There is a risk that this may occur.

In view of these conventional drawbacks, the present invention aims to reliably detect the marks on the tape L and obtain a stable output signal even if the color of the measurement object changes.

Therefore, in order to achieve this purpose, this invention passes light from a light source through a beam splitter and an objective lens with a sufficiently large aperture, and passes the light onto a measurement object that is moving at a constant speed and a predetermined distance above the measurement object. When the mark on the measurement object 1 is detected, the reflected light is guided to the line sensor through the objective lens, beam splitter and cylinder lens, and the change in the inclination angle of the surface of the measurement object is detected. The detection signal of the mark is output only when the mark is detected.

An embodiment of the present invention will be described below with reference to the drawings.

, that is, in FIG. 1, numeral 1 is a light source, for example L
It is composed of ED. 2 is a lens, 3 is a beam splitter, 4 is an objective lens, and 5 is a measurement object, for example, a cloth tape. Reference numeral 6 denotes marks provided at predetermined intervals on the measurement object, 7 a cylinder lens, 8 a line sensor, 9 a control line, and 10 an output circuit.

In this configuration, light from a light source 1 is made into a parallel beam by a lens 2, passes through a beam splitter 3, is further focused by a lens 4, and is irradiated onto a measurement object 5 and a mark 6. Then, the reflected light from the measurement object 5 passes through the lens 4 again, is reflected by the beam splitter 3, passes through the cylinder lens 7, and enters the line sensor 8. When this incident light exceeds a predetermined level, it is subjected to logic and mathematical processing by the output circuit 10, and then an output signal is generated.

issue a number.

FIG. 2 shows the reflection state of the measuring object 5, for example, the cloth tape 1, and the light entering the lens 4'. As shown in Figure (a), the reflection angles on the cloth surfaces are different, and therefore the light is reflected over a wide range. This is because the magnitude of the inclination of the reflective surface on the cloth tape is different. Figure (0) shows the reflection situation at the mark 6 portion and the light incident on the lens 4. On this mark surface, the angle of the reflective surface is smaller than that on the cloth surface, so the light is concentrated. reflect.

In addition, FIG. 3 shows the distribution of light on the light receiving surface of the line sensor 8, and as shown in FIG.
If it is made of cloth, the spread of the reflected light increases depending on its weaving method, but as shown in FIG. By receiving the spread of the light with the line sensor 8, the mark 6 and the measurement object 5, ie, cloth, can be identified. The position of the reflected light on the line sensor 8 varies depending on the large undulations of the measurement object 5, that is, the cloth surface and the mark 60 surface, but the difference can be easily seen by looking at the standard deviation. Looking at it another way,
In order to allow light to enter the line sensor 8 in this way, the measurement object 5 must be traveling at a constant speed, and in this respect, the sensor in this case can be said to be a speed or frequency domain sensor. Measuring object 5 at a constant speed
By sending the mark 6, it is possible to detect the passed mark 6 and perform processing such as cutting at a certain distance.

Note that it is undesirable for the reflected light to change due to reflection on the surface of the measurement object 5, so the control line 9 is set so that the intensity of the light at the light receiving surface of the line sensor 8, that is, the point A in FIG. It is desirable to control the light source l through. In the case of a normal photoelectric sensor, since the point A is viewed as a spot, the problems described in the conventional drawbacks occur. On the other hand, when the line sensor 8 is used, after receiving the distribution of O and 1 caused by contrast/trust in a register, the output circuit 10 performs logical and mathematical processing to estimate the position of the mark 6. can be done.

It goes without saying that the measurement conditions should be determined by using a lens 4 that is sufficiently close to the measurement object 5 and has a large aperture.

As described above, this invention passes light from a light source through a beam splitter and an objective lens with a sufficiently large aperture, and places the light at a predetermined interval above a measurement object that is moving at a constant speed and the measurement object. The light is irradiated onto the mark, and the reflected light is guided to the line sensor via the objective register, beam splitter, and cylinder lens, and detects changes in the inclination angle of the surface of the measurement object. Since the mark detection signal is output, the mark can be detected reliably and an extremely reliable mark sensor can be used.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the mark sensor according to the present invention, Fig. 2 is a diagram showing the relationship between the reflection situation on the measurement object and the light incident on the lens, and Fig. 3 is a diagram showing the relationship between the reflection situation on the measurement object and the light incident on the lens. It is a figure showing a state. l...Light source, 2...Lens, 3...Beam splitter, 4...Objective lens, 5...Measurement object, 6...
- Mark, 7°゛° cylinder lens, 8... Line sensor, 9... Control line, 1o-... Output circuit. Patent applicant Yamatake Honeywell Co., Ltd.

Claims (1)

[Claims] Light from a light source is passed through a beam splitter and an objective lens with a sufficiently large aperture, and is irradiated onto a measurement object that is moving at a constant speed and marks placed at predetermined intervals on the measurement object, and the reflected light is is guided to the line sensor through the objective lens, the beam splitter, and the cylinder lens, and detects changes in the inclination angle of the surface of the measurement object, and detects the mark only when the mark on the measurement object is detected. A mark sensor that outputs a signal.