JPS5942241B2 - The first step is to get the job done. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dimension detection device that can photoelectrically detect the dimensions of a paper-like object while eliminating the influence of positional deviations, twists, etc. that occur during conveyance of the paper-like object.

Conventionally, a means for automatically detecting the dimensions of a paper-like object in a direction perpendicular to the transport direction on a conveyance path for conveying a paper-like object is, for example, one-dimensionally arranging light receivers consisting of a large number of light receiving elements on the conveyance path. A method of photoelectrically counting the length of the shadow of a paper-like object is known.

However, in such a method, when a paper-like object is misaligned or twisted during transportation, the structure becomes quite complicated and the equipment is difficult to remove if the paper-like object is misaligned or twisted during transportation. There is a drawback that the whole system has to be expensive. Furthermore, if the conveyed paper-like object is temporarily stopped and alignment and twist adjustments are made, it is possible to achieve high-precision detection at a relatively low cost with conventional dimension detection methods, but in this case, the processing speed is This significantly reduces the effectiveness of automated machines and labor-saving machines.

Therefore, there is a need for an inexpensive device that can eliminate these drawbacks, detect the dimensions of a paper-like object being conveyed with high accuracy while it is being transported, and is capable of detecting the size of a conveyed paper-like object with high accuracy.

The present invention has been made in view of the above circumstances, and its purpose is to reduce the influence of detection errors caused by positional deviations and skews of the conveyed paper-like object in the direction perpendicular to the travel of the conveyed paper-like object, and to The present invention aims to provide an inexpensive dimension detection device that can be detected photoelectrically.

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 4.

FIG. 1 is a basic layout diagram showing the optical system of the present device.
In the figure, 1 is a rectangular paper-like object with a constant width, and this paper-like object 1 is a conveyor belt 2, 2, and 2', which is a conveyor device.
2' and transported at a constant speed in a direction perpendicular to the plane of the paper and in the width direction of the paper-like object. Also, 3, 3'
is a lamp as a light source, and illumination members such as a plano-convex lens 4, which receives the light from the lamps 3 and 3' and illuminates it uniformly.
4', the parallel light beams 5..., 5'... are arranged so that both ends of the paper wag-like object 1 are uniformly irradiated. Further, reference numerals 6 and 6' denote light collecting boxes that collect the transmitted light that has passed through the paper-like object 1, and these light collecting boxes 6 and 6'
Diffusion plates 7, 7'' for diffusing light are installed at the top of the ``, and light receivers 8, 8' are installed at the bottom.

In the optical system having the above configuration, a portion of the uniform transmitted light 5..., 5'' that has passed through the plano-convex lenses 4, 4'' is attenuated by passing through the paper-like object 1, and is attenuated by the diffusion plate 7. , 7'', and the other part is not attenuated by the diffuser plate 7, 7'.
reach. Therefore, the illuminance of the diffuser plates 7, 7'' will differ, but the illuminance of the light collecting boxes 6, 6'' and the diffuser plates 7, 7
Due to the action of ``, the light incident on the diffuser plates 7, 7'' is averaged and reaches the light receivers 8, 8''.

The light condensing boxes 6, 6'' have the same principle as optical integrating spheres whose inner walls are painted white, and the diffusing plates 7, 7'' are made of, for example, a milky white glass member.

Moreover, FIG. 2 is a plan view showing the positional relationship between the light-receiving area of transmitted light and the paper-like object that can be run.

In other words, 9 and 9'' are areas of the diffuser plates 7 and 7'' that are uniformly irradiated and receive light, and when the paper-like object 1 travels in the direction of the arrow, the paper is The width of the diffuser plates 7, 7'' is set to be sufficiently large so that the light illuminates the entire width of the shaped object 1 and passes through the light-receiving areas 9, 9''. Next, FIG. 3 shows the light receivers 8 and 8 shown in FIG.
This is an example showing a processing circuit for electrical signals obtained from ``.

In the figure, 8, 8' are photoreceivers, 11, 1' are preamplifiers,
12 is an adder, and 13 is an integrator. Further, 14 is a photoelectric switch that detects the position of the traveling paper-like object 1, and 15 is a timing pulse generation circuit. Next, the operation of the present invention based on the above configuration will be explained.

Now, when the paper-like object 1 passes through the irradiation and light-receiving area on the diffuser plates 7 and 7'', photocurrents 1t and I'' are generated from the light receivers 8 and 8''.
t is obtained. Then, the preamplifiers 11 and 1' convert the signals into voltage signals Vlt and v'1t of appropriate levels, which are then added together by the adder 12 to obtain the signal V2t.
The integrator 13 integrates the input signal V2t for a predetermined time and outputs V. is obtained. That is, the output V. is expressed by the following equation. Note that the integration time is determined by the timing pulse T of the timing pulse generation circuit 15. On the other hand, since the photoelectric switch 14 emits a position signal S when the paper-like object 1 is transported and reaches a predetermined position, the timing pulse generation circuit 15 receives the position signal S and determines the integration time of the integration circuit 13. Generate pulse T.

Therefore, the following effects can be obtained by the present device.

That is, both ends of the paper-like object being conveyed are connected to lamps 3, 3.
! The light is uniformly irradiated by the plano-convex lenses 4 and 47, is received by the light receivers 8 and 8'' for a predetermined period of time via the diffusion plates 7 and 7'', and the photocurrent is integrated by the integrating circuit 13. As a result, equivalent illumination and light-receiving areas are obtained as shown by 21 and 2'' in FIG. Now, the length of the paper-like object 1 is 11, the width is 12, and the length of each part of the illumination/light receiving part is L.

, Ll, L2, the area of the illumination area is S, the area of the diagonal line is Sl, S2, and the output of the integrator 13 when no paper-like object is being conveyed is VB (output when all parts of SO are integrated). ), and if the output of the integrator 13 when the paper-like object is conveyed is VO, then the following equation holds true.

Further, if the width 12 of the paper-like material 1 is constant and only the length 1 differs, then the following holds true.

Therefore, the length 11 of the paper-like object 1 is It is expressed as

Therefore, by setting the illumination/light receiving area as large as necessary, the traveling paper-like object will not protrude from this area, and the area (S1+S2) is unrelated to the positional deviation X during transportation.

Therefore, it is possible to detect the length 11 of the paper-like object 1 without being affected by the conveyance position shift. Next, the influence of the twist θ of the paper-like object 1 will be explained.

Now, in the case of twist θ-0, the area of the shaded part is S, θ\
If the area in the case of O is S'', the area error ε is as follows.

In the above equation, (1-...) is the case when the length 1 of the paper-like object 1 tilted at an angle θ is directly detected, so by detecting the length 11 of the paper-like object 1, the skew can be reduced. Effect decreases to L2/11.

Therefore, by making L2 as small as possible, the influence of skew can be reduced. Next, when the paper-like object has different partial transmittances and this affects the length detection accuracy, a detection device according to a modification of the present invention shown in FIG. 5 is effective.

In the figure, φA and φB are uniform illumination lights that are partially blocked by the traveling paper-like object 1, and the one-dimensional array of light receivers 31 and 3'
The light is received by the That is, each of the light receivers 31 and 3' is a multi-element light receiving element array having sufficient resolution for the required detection accuracy. Thus, the respective outputs of the photodetector 31 consisting of the photodetector arrays SA, ~SAO and the photodetector 3'' consisting of the photodetector arrays SBl~SBO are sequentially switched by the multiplexers 32, 32'' and sent to the Schmitt circuits 33, 33! I am beginning to be guided.

The above-mentioned Schmitt circuits 33, 33'' output a signal of 0 when the receiver is not blocked by a paper-like object and outputs a certain amount or more, and outputs a signal of 0 when the receiver is not blocked by a paper-like object and outputs a certain amount or more. When the output is output, a signal of ``1'' is generated.
In this case, by setting the switching speed of the multiplexers 32, 321 to be sufficiently high (compared to the transport speed of the paper-like object 1), the Schmitt circuits 33, 33' are opened to the regions 21, 2' shown in the fourth figure, and the hatched area is opened.゛1 - other parts “0”
” and generates signals A and VB which are replaced with time-series signals.

These signals VA and B are integrated for a predetermined time by integrators 34 and 34'', and the sum of both outputs is taken by an adder 35, so that a signal V related to the length that is not affected by the difference in partial transmittance is obtained.
. can be obtained. In addition, Schmitt circuits 33, 3
A similar effect can be obtained by using the outputs A and VB from the integrators 34 and 34'' as control signals for the integrators 34 and 34'' and integrating the constant voltage signal. In one embodiment of the present invention, the photocurrents obtained from the photodetectors are added by an adder, and the output of this adder is integrated by an integrator for a predetermined time, but the invention is not limited to this. The photocurrent may be individually integrated by an integrator, and the integrated values may be added by an adder.

Further, subtraction may be performed using a subtracter instead of an adder; in short, an arithmetic unit may be used. As explained above, the present invention illuminates both ends of a paper-like object to be conveyed, and a photoreceiver is installed in the illuminated/light-receiving area, and the photocurrent obtained from this photoreceiver can be added or subtracted. The present invention is characterized in that the width dimension of the paper-like object is detected while removing the displacement and twist of the paper-like object by performing calculations.

Therefore, there is no need for a photoreceptor consisting of many elements or a digital processing circuit, etc., and high-precision detection is possible without being affected by misalignment or twisting of the paper-like object being conveyed. This has practical effects such as lower cost.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of a dimension detection device showing an embodiment of the present invention, FIG. 2 is a plan view showing an example of a paper-like object to be inspected in a conveyed state, and FIG. 3 is a diagram of a signal processing circuit in the same device. System diagram,
FIG. 4 is a schematic plan view for explaining the effects of the present invention, and FIG. 5 is a system diagram of a signal processing circuit showing a modification of the present invention. 1...Paper-like object, 4,4''...Lighting member, 8,8t31,3''...Light receiver, 12,3
5... Arithmetic unit.

Claims (1)

[Claims] 1. A conveyance device that conveys a rectangular paper-like object with a constant width at a constant speed in the width direction, an illumination member that uniformly illuminates both side edges of the paper-like object conveyed by this conveyance device, and A pair of light receivers each receives light passing through both ends of a shaped object and converts the amount of light received into an amount of electricity, and the photoelectric signals obtained from this pair of light receivers are added together and the added output is calculated. and a calculation means that accumulates over almost the entire length of the paper-like object in the transport direction, and the dimension of the paper-like object to be transported in a direction perpendicular to the transport direction is detected from the accumulated value by the calculation means. A device for detecting the dimensions of a paper-like object.