JPH07151534A - Paper sheet thickness detecting mechanism - Google Patents

Abstract

PURPOSE:To simplify setting adjustment and output adjustment for a sensor and to detect the number of paper sheets at the time of multi-feed and detect the thickness of paper sheets different in thickness. CONSTITUTION:In order to detect the thickness of paper sheets, there are provided a reference roller 1 and a detecting roller 2 which can be displaced up and down according to the thickness of a paper sheet. The displacement of the detecting roller 2 is enlarged and transmitted to a scale 6, an encoder 7 counts the brightness and darkness of a slit on the scale 6, and the thickness of a paper sheet is detected by a digital amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper sheet thickness detecting mechanism, and more particularly to a paper sheet thickness detecting mechanism having a function of detecting the displacement of a detection roller by an encoder and detecting the thickness digitally. Regarding

[0002]

2. Description of the Related Art A conventional paper sheet thickness detecting mechanism, as shown in FIG. 2, expands a reference roller 1, a detecting roller 2 which is displaced by the thickness of the sheet, and a displacement of the detecting roller 2. It has a detection lever 8 and a magnetic sensor 9. The detection roller 2 is set at a position wider than the reference roller 1 by the thickness interval of the paper sheet.

Next, the operation of this conventional example will be described.

When the processing start trigger sensor 10 detects a sheet, the thickness detection processing is started. When the paper sheet is conveyed between the reference roller 1 and the detection roller 2, the detection roller 2 is displaced due to the thickness of the paper sheet. If the thickness of the paper sheet is less than or equal to a predetermined thickness, the detection roller 2 will not be displaced. In the case of a paper sheet having an abnormal thickness or a double-fed paper sheet corrected with cellophane tape or the like, the detection roller 2 is displaced, and the displacement is magnified by the detection lever 8. The magnetic sensor 9 detects the displacement of the tip of the detection lever 8. The detection unit detects the thickness abnormality by comparing the voltage change of the magnetic sensor 9 with the voltage level at which the thickness abnormality should be made.

[0005]

In the above-described conventional paper sheet thickness detecting mechanism, when the paper sheets are double-fed, it can be determined that they are double-fed, but there are two or three sheets. It is impossible to determine the number of sheets. Further, there is a problem that it is difficult to adjust the attachment and the output of the magnetic sensor.

[0006]

SUMMARY OF THE INVENTION The present invention detects a displacement of a detection roller when a paper sheet is conveyed between a reference roller and a detection roller, and detects a paper sheet having an abnormal thickness. In the paper sheet thickness detection mechanism for detecting the double-fed paper sheets, the displacement of the detection roller is magnified and transmitted to the scale, and is detected by the encoder to detect the thickness digitally. It is characterized by that.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a side view showing an embodiment of a paper sheet thickness detecting mechanism according to the present invention. This paper sheet thickness detection mechanism, in order to detect the thickness of the paper sheet, a reference roller 1,
A detection roller 2 that can be displaced up and down depending on the thickness of the paper sheets,
Gear 4, gear 5, for increasing the displacement of the detection roller 2
It has an encoder 7 which is arranged with the scale 6 and counts the scale 6.

Next, the operation of this embodiment will be described.

When the processing start trigger sensor 10 detects the sheet conveyed to the sheet thickness detection mechanism, the thickness detection process is started. When a paper sheet plunges between the reference roller 1 and the detection roller 2, the detection roller 2 is displaced according to the thickness of the paper sheet. At this time, the detection roller 2 is set in advance at a position widened from the reference roller 1 by the thickness interval of the paper sheet. For this reason, the detection roller 2 is not displaced when a sheet having a predetermined thickness or less is conveyed. When a paper sheet having an abnormal thickness or a double-fed paper sheet that has been corrected with cellophane tape or the like is conveyed, the detection roller 2 rotates about the rotation center 3, and the gears 4 and 4 are rotated. The scale 6 is displaced via 5. At this time, the displacement of the detection roller 2 is enlarged and transmitted to the scale 6 according to the gear ratio and the arm ratio. In order to accurately transmit the displacement of the detection roller 2, two gears 5 are overlapped with each other to engage with the gear 4 so as to eliminate backlash. The scale 6 has slits arranged at equal intervals perpendicular to the displacement direction of the scale, and the encoder 7 counts the brightness of the slits of the scale 6. The same square wave pulse as the count number is output from the encoder 7. If the number of slits to be counted is calculated according to the thickness, the thickness of the paper sheet can be detected by the rectangular wave pulse output from the encoder 7.

[0011]

As described above, according to the present invention, in the paper sheet thickness detection mechanism, the encoder counts the displacement of the detection roller and indicates it as a digital amount, so that the number of paper sheets can be detected during double feeding. It is also possible to detect the thickness of paper sheets with different thicknesses by changing the discrimination count value that should be an abnormal thickness, and there is no need for conventional magnetic sensor mounting adjustments and output adjustments. There is an effect that becomes.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a side view of a conventional example.

[Explanation of symbols]

 1 Reference Roller 2 Detection Roller 3 Rotation Center 4 Gear 5 Gear 6 Scale 7 Encoder 8 Detection Lever 9 Magnetic Sensor 10 Processing Start Trigger Sensor

Claims (3)

[Claims] 1. When a sheet is conveyed between a reference roller and a detection roller, a displacement of the detection roller is detected to detect a sheet having an abnormal thickness or a sheet that has been double-fed. In the paper thickness detecting mechanism for detecting the thickness, the displacement of the detection roller is enlarged by a gear and transmitted to a scale, and is detected by an encoder to detect the thickness by a digital amount. Thickness detection mechanism. 2. A processing start trigger sensor for detecting a sheet to start a thickness detection process, a reference roller, and a position widened from the reference roller by a thickness interval of the sheet,
Displacement according to the thickness of the paper sheet plunging along the reference roller, and a detection roller that rotates when a paper sheet having an abnormal thickness or a double-fed paper sheet is conveyed, Scale with slits arranged at equal intervals perpendicular to the direction, gear means for expanding the displacement of the detection roller to the scale according to the gear ratio and arm ratio, and counting the brightness of the slits and counting A paper sheet thickness detection mechanism, comprising: an encoder that outputs the same number of rectangular wave pulses. 3. The gear means is characterized in that two first gears are overlapped and meshed with a second gear.
The sheet thickness detection mechanism described.