JPH0843006A - Device for detecting thickness of paper - Google Patents

Abstract

PURPOSE:To detect the thickness of paper by reducing the effect of wrinkles. CONSTITUTION:Compressing rollers 1 and 2 are provided for a paper conveying path 6. Strong compressing force is applied on the compressing rollers 1 and 2 with springs 8 and 9. When the paper in conveyance passes between the compressing rollers 1 and 2, the wrinkles of the paper are smoothed out by the compressing force. Furthermore, the paper is conveyed between a thickness detecting roller 3 and a thickness reference roller 4. The amount of the displacement of the thickness detecting roller 3 corresponding to the thickness of the paper is read with a displacement-amount measuring part, and the thickness of the paper is measured. Since the wrinkles are smoothed out by the compressing forces of the compressing rollers 1 and 2 immediately before the detection of the thickness of the paper, the effect of the wrinkles is made small, and the thickness of the paper can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thickness detecting device suitable for accurately detecting the thickness of paper sheets and the like.

[0002]

2. Description of the Related Art In the prior art, as described in JP-A-59-60592, a very weak pressing force is applied to a paper sheet thickness detection roller, so that the paper sheet thickness folds with respect to the paper sheet thickness. The effect of wrinkles was great.

Further, when a strong pressure is applied to the paper thickness detecting roller for the purpose of removing wrinkles from the paper, the paper thickness detecting roller is used when the paper is not conveyed to the paper thickness detecting roller. And the reference roller are in contact with each other, the paper thickness detection roller and the reference roller are worn.

Further, since the paper thickness detecting roller does not have a conveying force, it causes a jam. When the sheet thickness detection roller is given a conveying force, the vibration at the time of conveyance is transmitted to the sheet thickness detecting unit, and the accuracy of detecting the sheet thickness deteriorates.

[0005]

In the above prior art, since the influence of wrinkles on the sheet thickness is not taken into consideration, the sheet thickness measurement error is large. It is an object of the present invention to remove wrinkles on a paper sheet and reduce an error in detecting the thickness of the paper sheet by using a pressure roller.

[0006]

In order to solve the above-mentioned object, a pressure roller is provided in front of the sheet thickness detecting roller on the sheet conveying path.

[0007]

[Function] Since the pressure roller is provided in front of the paper thickness detecting roller on the paper conveying path, the wrinkles of the paper are removed before the paper reaches the paper thickness detecting roller. The leaf thickness detection accuracy is improved.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. 1, 2 and 3.

FIG. 1 shows a mechanism diagram of a bill thickness detecting unit according to the present invention.

A strong pressing force is applied to the pressure roller (upper) 1 and the pressure roller (lower) 2 by the spring material 8 and the spring material 9. The pressure roller (upper) 1 and the pressure roller (lower) 2 rotate by receiving a driving force from a conveyance path drive source by the belt. The paper sheet 11 is conveyed on the conveying path 6 and passes between the pressure roller (upper) 1 and the pressure roller (lower) 2 and between the thickness detection roller 3 and the reference roller 4. When the paper sheet 11 passes between the pressure roller 1 and the pressure roller 2, a pressing force is applied by the pressure roller 1 and the pressure roller 2 to remove wrinkles. The angle sensor 5 is fixed to the transport path 6. The thickness detection roller 3 is fixed to the rotation shaft of the angle sensor 5 via the arm 10. A weak pressing force is applied to the thickness detection roller 3 in the direction of the reference roller 4 by the elastic member 7 connected to the arm 10. Therefore, when the paper sheet 11 is not conveyed, it is in contact with the reference roller 4. The position of the thickness detection roller 3 at that time becomes the sheet thickness reference position. When the paper sheet 11 passes through the paper sheet thickness detection unit 3, the position of the paper sheet thickness detection unit 3 changes according to the thickness of the paper sheet 11. The rotation angle of the rotation shaft of the angle sensor 5 changes according to the amount of positional displacement of the thickness detection unit 3. The thickness of the paper sheet 11 is detected based on the displacement amount of the rotation angle.

The sheet thickness detection control unit will be described with reference to FIG. The output voltage value of the angle sensor 5 changes in proportion to the displacement amount of the rotating shaft. The output voltage value is amplified by the AMP 12. The amplified output voltage is converted into a digital value by the A / D cone converter 13 and input to the CPU 14. By the above, the thickness of the paper sheet 11 is obtained.

Referring to FIG. 3, the difference between the thickness detection signals when the wrinkles of the paper sheet 11 are expanded and when the wrinkles are not expanded by the pressing force of the pressure roller (upper) 1 and the pressure roller (lower) 2 will be described. To do. Waveforms (a), (b), and (c) show thickness detection signals. A thickness detection signal of a paper sheet having no wrinkles is shown in (a). A thickness detection signal of a wrinkled paper sheet is shown in (b). In this case, the thickness detection signal fluctuates due to the amount of displacement caused by wrinkles and the impact force that wrinkles give to the thickness detection roller 3, resulting in a thickness measurement error. Pressure roller (upper)
1, (c) shows a thickness detection signal which is detected after the wrinkles of the paper sheet are extended by the pressing force of the pressure roller (lower) 2.
Since the thickness is detected after the wrinkle is stretched, the measurement error due to the influence of the wrinkle can be reduced.

[0013]

According to the present invention, since the wrinkles are stretched by the pressing force of the pressure roller immediately before the thickness detection of the paper sheet, the thickness of the paper sheet is detected by reducing the influence of the wrinkles. be able to.

[Brief description of drawings]

FIG. 1 is a configuration of a paper sheet thickness detection mechanism unit.

FIG. 2 is a block diagram of a paper sheet thickness detection control unit.

FIG. 3 is a sheet thickness detection signal.

[Explanation of Codes] 1 ... Pressure roller (upper), 2 ... Pressure roller (lower), 3 ... Thickness detection roller, 4 ... Reference roller, 5 ... Angle sensor, 6 ... Conveyance path, 7 ... Elastic member, 8 ... Spring material, 9 ... Spring material, 10 ... Arm, 11 ... Paper sheets, 12 ... AMP (amplifier), 13 ... A / D converter, 14 ... CPU.

Claims (1)

[Claims] 1. A sheet conveying path, a thickness detecting roller for detecting the thickness of a sheet, a reference roller, an elastic member for bringing the thickness detecting roller into contact with the reference roller, and the thickness detecting roller. In a sheet thickness detecting device for measuring the thickness of the sheet conveyed between the reference roller and the thickness detection roller, which is configured by a displacement amount measuring unit for reading the displacement amount of
A pressure roller is provided in front of the thickness detection roller and the reference roller, and a spring member for applying a pressing force to the pressure roller is provided, and the pressure roller is used to detect the thickness of the paper sheet before the thickness of the paper sheet is detected. A sheet thickness detecting device characterized in that the sheet is detected by pressing the sheet.