JPS62165291A - Counting device for number of sheets - Google Patents

Abstract

PURPOSE:To attain counting with high accuracy and exactness by providing a setting apparatus which gives a threshold that decides the stage of an object to be counted, and a counting means which gives the threshold from the setting apparatus to an output signal from a filter circuit, and counts a binarization signal. CONSTITUTION:Only stage displacement signals are taken out at a high-pass filter 19 and a low-pass filter 21, and a signal set so that a stage fluctuation can count the threshold is generated based on a displacement on a sheet of paper due to the overlapping quantity of a printed matter 4 as a reference, with a low-pass filter 20, a detection level setting apparatus 23, and an adder 22. By performing a subtraction between both two signals at a differential amplifier 24, a signal SG2 consisting of only the stage displacement on which the threshold is added can be obtained. And by inputting the signal SG2 to a Schmitt circuit, its output becomes the binarization signal like a signal SG3, and it is counted at a counting circuit 26, and a circuit is constituted as the one having a function to perform the subtraction and the reset of a pulse with a non-paper detection signal SD and a reset switch 27. Based on the count signal, the number of printed sheets are displayed at a count display apparatus 28.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sheet counting device for counting sheets of printed matter, which is applied to, for example, a printing machine.

[Prior Art] In general, the books printed by commercial rotary offset presses come in a variety of sizes, from very thin to very thick, and are printed with designs with strong color contrast. There is a technique shown in FIG. 4 as a method for counting printed books in various combinations such as paperbacks, folding, etc.

In other words, in FIG. 4, a laser projector 1 is installed in the middle of the sheets printed by a printing machine, overlapping each other in a shim shape, and the laser beam emitted from the projector 1 is directed onto the conveyor belt 3. A reflecting mirror 2 is disposed so as to be obliquely in front of the traveling printed material 4. On the other hand, the laser beam hitting the printed material 4 is reflected by the printed material 4, and the configuration is such that the pair of light intensity detectors 5.6 detects the overlapping step portion of the printed material by receiving this reflected light. It has become.

In such a configuration, light! As a method of detecting a step part from the signal of the i-detector 5.6, in the part where there is no step, the signal level is high because the amount of light hitting the light amount detector 5 is in the direction of receiving specularly reflected light. .

On the other hand, since the amount of light hitting the light amount detector 6 is in the direction of receiving diffusely reflected light, the signal level is low.

Here, when the printing book moves and the stepped portion is illuminated, there is a moment when the signal level of the light amount detector 5.6 is reversed at a certain position of the stepped portion. Therefore, the number of printed matter 4 can be counted by detecting the portion where the rotation is rapidly reversed. Note that in the case of a pattern with strong contrast, both signal levels fluctuate in phase and are not detected.

[Problem to be Solved by the Invention 1] By the way, in a printed book that is folded over and over like a newspaper, it is possible to measure the moment when the level is reversed.

However, in the case of thin paper sheets that are printed using a commercial rotary offset press, it is very difficult to detect the reversed portions using the method described above because the signal of the stepped sharp edges changes discontinuously. be. In addition, since it is said that the minimum spot diameter of a laser for light projection is technically a diameter of 80 μm, the spot may vary depending on the thickness of the thin paper sheet.
It is also not easy to accurately detect a step-shaped reflection change of 0 um.

The present invention has been made in order to solve the above-mentioned problems, and its purpose is to provide a highly reliable sheet counting device that can count the number of printed materials with high precision and reliability. It's about doing.

[Means for Solving the Problems] In order to achieve the above object, the sheet counting device according to the present invention includes a light spot position detection element, a light spot source, and a force, and detects the difference in level of a sheet-like object to be counted. A light spot displacement detector that detects displacement as a light spot displacement, a filter circuit that extracts only a level difference signal from the signal output from the light spot displacement detector, and a threshold that determines the level of the object to be counted. The present invention is characterized in that it comprises a setting device for giving a value, and a counting means for giving a threshold value from the setting device to the output signal from the filter circuit and counting the binary signal.

[Function] In the counting device having the above configuration, the displacement of the step of the sheet-like object to be counted is detected by the light spot displacement by the light spot displacement detector ψ, and the apparent fluctuation displacement due to the picture pattern (picture noise signal) is detected by the light spot displacement detector ψ. ) is removed by the electric filter circuit, and as a result, the number of sheets to be counted can be counted with high precision and reliability.

In the present invention, instead of detecting the change in the direction of reflected light due to the step shape of the printing book, a method is basically adopted in which the displacement of the step of the printing book is detected by the displacement of the light spot. This is handled by removing the noise using an electric filter.

That is, recently, the manufacturing of elements for detecting light spot displacement has become stable, and highly accurate devices have been commercialized. The detection accuracy with this type of element has a resolution of 1 .mu.m, and it is possible to sufficiently detect a paper sheet of 60 .mu.m. Therefore, in order to faithfully detect changes in the cross-sectional shape of a printing book being conveyed in a sammel pattern using the displacement of the light spot, it is necessary to adjust the electrical filter characteristics to By changing according to
Only changes in cross-sectional shape can be extracted. FIG. 3 shows this signal. EXAMPLE 1 Hereinafter, an example of the present invention based on the above concept will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and shows a configuration in which a light spot position detector measures step displacement in order to count the number of printed books. That is, in FIG. 1, the conveyance belt 3 is driven by the conveyance roller 7, and the printed matter 4 is sent out one after another. The configuration for detecting the level difference in the printed matter 4 is such that the driving power supply 9 moves the LED driving circuit 10G to light the LED 12, and the lighting light is focused by the light projecting lens 13 to form the printed matter 4.
Apply to. On the other hand, the PSD 1 driven by the signal calculation circuit 11
5, the light reflected by the printed matter 4 is condensed by a light-receiving lens and applied to the detection surface, so that the step displacement signal 16 changes as the light spot moves on the detection surface.

FIG. 2 shows a circuit that processes the electrical signal of the step displacement of the printed material detected in FIG. 1. In Figure 2,
First, for signal processing, the information input is an optical micro-displacement meter 17 configured as shown in FIG. This is provided by a detection level setter 23 that provides a threshold value for the calculation, and a reset switch 27 that cancels the counted value. On the other hand, since the step displacement signal SG1 as shown in FIG. 3 inputted from the optical micro displacement meter 17 contains pattern noise of the printed matter 4, it is necessary to erase this to make a signal representing only the step displacement. As this method, since the frequency of stage displacement and pattern noise changes depending on the conveyance speed, the frequency output from the one-rotation speed detector 8 is set to F-V.
The converter 18 converts it into a voltage signal, and the bypass filter 19
, the cutoff frequency of the low-pass filter 20 is varied according to the conveyance speed using this voltage signal. This filter 19
．． When the input signal SG1 is applied to the filter 20, the filter characteristics move with the conveyance speed, so that the frequency component of the picture noise can be eliminated. Then, the bypass filter 19 and the low-pass filter 21 take out only the stage displacement signal, and the low-pass filter 20, the detection level setter 23, and the adder 22 set the threshold based on the displacement on the paper due to the overlapping area of the printed object 4. Create a signal whose value is set so that step changes can be counted. These two signals are transferred to a differential amplifier 24.
When subtracted by
You can get G2. Then, when this signal SG2 is input to the Schmitt circuit, its output becomes a binary signal like signal SG3, which is counted by the counting circuit 26, and functions to reduce and reset the pulse using the paper out detection signal SD and the reset switch 27. The circuit has a

Based on this count signal, mark til1 is displayed on the count display 28.
The number of sheets is now displayed.

The following effects can be obtained. In other words, by detecting the displacement of the steps of the printing book by the displacement of the light spot and removing the apparent fluctuation displacement due to the pattern using an electric filter, the manufacturing of the detection element using the light spot displacement method is stable and highly accurate (resolution: It becomes possible to count the number of sheets at ±1μTrL). In addition, since the apparent fluctuation frequency due to the image changes depending on the conveyance speed, it is possible to eliminate the influence of the conveyance speed by automatically varying the cutoff frequency of the electrical filter characteristics according to the conveyance speed of the printing book. becomes. From the above, it is possible to count the number of sheets with high precision and reliability.

Note that the present invention can be similarly applied to counting the number of sheets, labels, banknotes, etc.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a highly reliable sheet counting device that is capable of counting the number of printed matter with high accuracy and reliably.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are configuration diagrams showing one embodiment of the present invention,
FIG. 3 is a waveform diagram for explaining the present invention in detail, and FIG. 4 is a configuration diagram for explaining the conventional counting method. 7... Conveyance roller, 8... Rotation speed detector, 9...
- Drive power supply, 10... LED drive circuit, 11... Signal calculation circuit, 12... LED, 13... Light emitting lens, 14... Light receiving lens, 15... PSD, 16...
- Stage displacement signal (SG1), 17... Optical micro displacement meter, 18... F-■ converter, one... bypass filter, 20... low pass filter, 22... adder,
23...Detection level setter, 24...Differential amplifier,
25... Schmitt circuit, 26... Counting circuit, 27
...Reset switch, 28...Counting display, SD
...paper out detection signal, SG1...stage displacement signal, SG
2...After bandpass signal change, SG3...2
(duplex signal.

Claims (1)

[Claims] A light spot displacement detector consists of a light spot position detection element and a light spot source, and detects the displacement of a step on a sheet-like object to be counted by the light spot displacement, and a signal output from this light spot displacement detector detects the step difference. a filter circuit that extracts only the signal; a setter that provides a threshold value for determining the stage of the object to be counted; and a setter that provides the output signal from the filter circuit with the threshold value from the setter and its binary 1. A number-of-sheets counting device comprising: counting means for counting digitization signals.