JPH02169440A - Device for detecting piece of paper - Google Patents

Abstract

PURPOSE:To surely detect the end portion of a piece of paper not by means of the color or reflectance of the piece of paper or letter paper by providing a detecting device for detecting the end portion of the piece of paper from the condition of the analysis of a reflected light based on the irregularity of the end portion. CONSTITUTION:Light in a first position is projected from the light projecting portion 31 of a detecting device onto a piece of paper 2 attached to a sheet of letter paper being conveyed in one direction, and the light reflected from this piece of paper 2 is received by the light receiving portion 32 thereof. Then, the condition of the analysis of the reflected light is observed from the received light receiving signal by an information processing portion 33 to judge whether the reflected light is the end portion of the piece of paper 2 or not. Thus, the end portion of the piece of paper can be surely detected not by means of the color or reflectance of the piece of paper 2 or the letter paper 1.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a paper piece detection device that detects the edge of a piece of paper attached to a letter, such as a stamp or an address label, and measures its position, size, etc. It is related to.

(Prior art) When automatically processing letters such as mail, it may be necessary to measure the position and size of pieces of paper such as stamps and address labels attached to the letters. A paper piece detection device is used for the measurement.

Conventionally, this type of paper strip detection device detects the edge of a paper strip by optically measuring the differences in color and reflectance between the paper strip and the surrounding letter surface. I was trying to measure the location and size.

[Problem to be solved by the invention]

By the way, there are various types of letters and pieces of paper that we handle.
The color and reflectance are not necessarily constant, and therefore, the above-mentioned conventional paper piece detection apparatus has the disadvantage that detection may not be performed successfully depending on the color or reflectance of the paper piece or letter.

The present invention has been proposed in view of the above points, and its purpose is to accurately detect the edge of a piece of paper without being affected by the color or reflectance of the piece of paper or letter. An object of the present invention is to provide a paper piece detection device.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a light projector that irradiates a light beam of a single phase onto a piece of paper attached to a letter that is conveyed in one direction, and a light receiver that receives the light beam reflected from the piece of paper. , and an information processing section that observes the state of diffraction of reflected light from the received light signal and determines whether or not it is at the end of the piece of paper.

[Effect]

In the paper piece detection device of the present invention, the light emitting section of the detection device irradiates a light beam of a single phase to a piece of paper pasted on a letter conveyed in one direction, and the light receiving section The information processing unit receives the reflected light beam and observes the state of diffraction of the reflected light from the light reception signal to determine whether or not it is the end of the piece of paper.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of the paper piece detection device of the present invention. In FIG. 1, 1 is a letter, and 2 is a piece of paper pasted on the letter 1 to be detected. And the letter l
is transported in the direction of the arrow at a predetermined speed by a transport mechanism (not shown). On the other hand, 3A, 3B, 3C
, . . . are detection devices, and a plurality of them are arranged in a line in a direction perpendicular to the conveyance direction of the letter 1, and output signals (judgment results) of each detection device 3A, 3B, 3C, .
is input to the paper piece position calculation section 4.

Note that this embodiment shows a configuration for one-dimensionally measuring the position and size of a piece of paper 2, and therefore a plurality of detection devices 3 are installed in a direction perpendicular to the conveying direction of the letter l.
A, 3B, 3C, . . . are arranged in a negative column. Therefore, if only -dimensional measurement is required, at least one detection device is sufficient.

The internal configuration of the detection devices 3A, 3B, 3C, ... will be described later, but their functions are as follows: As the letter l is conveyed, the detection devices 3A, 3B, 3C, ... It sends out a signal indicating whether or not the point hit by the light is approaching the edge of the piece of paper 2. Then, the paper piece position calculation unit 4 receives signals indicating the end of the paper piece 2 from each of the detection devices 3A, 3B, 3C, . . . and calculates the position and size of the paper piece 2 from these signals. For example, detection devices 3B, 3C
If it is assumed that the piece of paper 2 passes under the letter l as it is conveyed, then the detection devices 3B, 3C,... first detect the edge, and then the edge is detected. The distance conveyed between the time and the time becomes the length (size) of the paper piece 2 in the conveyance direction. Moreover, detection devices 3A, 3B, and 3C.

. . , the length of the paper strip 2 in the direction perpendicular to the conveyance direction is obtained by multiplying the number of detection devices 3A, 3B, 3C, . . . by the arrangement pitch of the detection devices 3A, 3B, 3C, . In addition, the position of the piece of paper 2 is
It can be expressed by the distance from the reference point to the edges on both sides of the piece of paper 2, and in the direction perpendicular to the conveyance direction, it can be expressed by which detection device obtained the signal indicating the edge. .

FIG. 2 shows the detection devices 3A and 3B in FIG. 1.

3C, . . . shows the internal configuration of one of them. In FIG. 2, the detection device includes a light projector 31 that irradiates a single-phase light beam (irradiation light LL) onto a piece of paper 2 attached to a letter l that is conveyed in one direction, and a light beam reflected from the piece of paper 2. A light receiving section 32 that receives (reflected light L2) and a light receiving section 3
and an information processing section 33 that observes the state of diffraction of the reflected light L2 from the received light signal photoelectrically converted by 2 and determines whether or not it is the end of the piece of paper 2. Note that a laser light source is used as the light projector 31 to obtain the single-phase irradiation light Ll, and as the light receiver 32, a COD whose detection position can be selected is used to detect the state of diffraction of the reflected light L2. It will be done.

The principle of detecting the edge of the paper piece 2 in the detection device is as follows. That is, when the irradiation light L1 hits the flat part of the piece of paper 2 as shown in FIG. 2, the part that reflects the irradiation light L1 is relatively smooth, so the reflected light L2 also reaches the light receiving part 32 in a substantially straight line. The received light intensity relative to the position of the light receiving section 32 is simple as shown in FIG. On the other hand, when the irradiated light L1 hits the edge of the piece of paper 2 as shown in FIG. The light L2 is transmitted to the light receiving section 32
Therefore, the received light intensity with respect to the position of the light receiving section 32 becomes complicated as shown in FIG. Therefore, by measuring the disturbance in the received light intensity of the light receiving section 32 with respect to the position, it is possible to determine whether or not it is the end of the piece of paper 2.

FIG. 4 shows the configuration of the information processing section 33 in FIG. 2, and detects disturbances in the received light intensity with respect to position by subjecting the light reception signal of the light receiving section 32 to Fourier transformation (finite interval Fourier transformation). That's what I do. In FIG. 4, the information processing section 33 includes a Fourier transform section 331 that performs Fourier transform on the light reception signal of the light receiving section 32, and a peak detection section 3 that detects the peak value of the output signal of the Fourier transform section 331.
32, and a determination unit 333 that determines whether or not the end of the piece of paper 2 is located based on the peak value obtained by the peak detection unit 332.

Figure 5 is a more specific configuration diagram of Figure 4, and shows the A/D
i exchange section 334. Memory 335. The FFT processing section 336 corresponds to the Fourier transform section 331 in FIG.
37 corresponds to the peak detection section 332 in FIG.
38 corresponds to the determination section 333 in FIG. Also, 3
39 is a timing controller that controls the timing of A/D conversion and FFT.

Therefore, the Fourier transform results corresponding to the distributions of the received light intensity shown in FIGS. 6 and 7 are shown in FIGS. 8 and 9, respectively. As shown in the figure, only a single peak appears, but in the case of the light reception signal at the edge, two or more peaks appear as shown in Figure 9, and therefore the number of peaks and the peak level The peak detection units 332, 337
By comprehensively determining them in the determination units 333 and 338, it is possible to determine whether or not it is the end of the piece of paper 2.

〔Effect of the invention〕

As explained above, in the paper piece detection device of the present invention,
Since the edge of a piece of paper is detected from the state of diffraction of reflected light based on the irregularity of the edge of the piece of paper,
This has the effect that the edge can be reliably detected regardless of the color or reflectance of the letter.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the paper piece detection device of the present invention, FIG. 2 is a block diagram of the detection device in FIG. 1, FIG. 3 is a diagram showing the detection operation at the edge of a paper piece, and FIG. The figure is a block diagram of the information processing unit in Figure 2, Figure 5 is a more specific block diagram of the information processing unit in Figure 4, Figure 6 is a diagram showing the received light intensity on the flat part of the piece of paper, and Figure 7 8 is a diagram showing the received light intensity at the edge of the paper strip, FIG. 8 is a diagram showing the Fourier transform result at the flat part of the paper strip, and FIG. 9 is a diagram showing the Fourier transform result at the edge of the paper strip. In the figure, 1...Letter 2...Paper pieces 3A, 3B, 3C...Detection device 31...Light emitter 32... ... Light receiving section 33 ... Information processing section Ll ... Irradiation light Ll ... Reflected light 331 ... Fourier transform section 332 ... Peak detection section 333 ... Judgment section 334...A/D conversion section 335...Memory 336...FFT processing section 337...Peak detection section 338...Judgment section 339...Timing controller 4...・Paper piece position calculation unit

Claims (1)

[Claims] A light projector that irradiates a single-phase light beam onto a piece of paper attached to a letter that is conveyed in one direction; a light receiver that receives the light beam reflected from the paper piece; and a light receiver that detects the state of diffraction of the reflected light from the received light signal. A piece of paper detection device comprising: a detection device including an information processing unit that observes and determines whether or not it is an end of the piece of paper.