JPH0680272A - Conveyance clock generating device - Google Patents

Abstract

PURPOSE:To make it unnecessary to use a rotary encoder which is expensive by controlling the conveyance clock number, and generating an accurate conveyance clock suitable to the conveying speed of paper sheets. CONSTITUTION:When the front ends of paper sheets reach to the detecting position of a detector 14, the measurement by a paper sheet length measure 11 is started, and the counting of the conveyance clock fed from a divider 16 is started. When the rear ends of the paper sheets pass the detecting position of the detector 14, the counting of the conveyance clock fed from the divider 16 is finished, and the counting result is output to a comparator 13. The comparator 13 compares the counting result from the paper sheet length measure 11 and the counting number from a standard value setter 12, and outputs a converting signal to a dividing ratio setter 14 according to the result. The dividing ratio setter 14 outputs a renewed dividing value to the divider 16, and the divider 16 divides a standard clock fed from a standard clock generator 15 by the dividing value fed from the dividing ratio setter 14, and outputs the resultant value to the paper sheet length measure 11 as a new conveyance clock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier clock generator for generating a carrier clock synchronized with paper sheets that are nipped by a conveyor belt and conveyed.

[0002]

2. Description of the Related Art Generally, for a paper sheet that is nipped by a conveyor belt and conveyed on a conveyance path, a judgment device for judging the characteristics of the paper sheet is provided. In such a determination device, the characteristic data of the determination target paper sheet is sampled at regular intervals. When obtaining a sample of this characteristic data, a carrier clock synchronized with the carrier system is used so as not to be affected by carrier fluctuations of the carrier system.

However, a conventional device for generating a carrier clock uses a rotary encoder connected to a drive roller for moving a carrier belt, so that the carrier clock is generated by detecting a slit provided in the rotary encoder. It has become. The rotational force of the motor is transmitted to the drive roller. However, such a carrier clock generator has a drawback in that an expensive rotary encoder is used and a carrier clock that is actually synchronized with the carrier speed of the paper sheet is not generated.

For example, between the conveyor belt and the paper sheets,
Since a slip occurs and the transport clock by the rotary encoder and the actual transport speed of the paper sheet are deviated, an accurate transport clock has not been generated. Therefore, there are drawbacks in that an accurate transport clock that matches the transport speed of paper sheets is not generated, or an expensive rotary encoder is used.

[0005]

SUMMARY OF THE INVENTION As described above, it is intended to eliminate the disadvantages that an accurate transport clock that matches the transport speed of paper sheets is not generated or that an expensive rotary encoder is used. It is an object of the present invention to provide a carrier clock generation device that can generate a correct carrier clock that matches a paper sheet conveying speed and does not require an expensive rotary encoder.

[0006]

SUMMARY OF THE INVENTION A carrier clock generator according to the present invention comprises a detecting means for detecting conveyed paper sheets, a reference clock generating means for generating a reference clock, and a reference clock from the reference clock generating means. A carrier clock generating means for generating a carrier clock divided by a predetermined dividing ratio, while the sheet is detected by the detecting means,
Counting means for counting the carrier clocks generated by the carrier clock generating means, judging means for comparing the counting result of the counting means with a predetermined value, and judging the frequency division ratio according to the comparison result, and this judging means. It is composed of changing means for changing the frequency division ratio by the carrier clock generating means according to the result of the judgment.

[0007]

According to the present invention, the carrier clock is generated by detecting the conveyed paper sheets by the detecting means and dividing the reference clock from the reference clock generating means for generating the reference clock by a predetermined dividing ratio. The carrier clock generated by the carrier clock generator is counted while the sheet is detected by the detector, and the count result is compared with a predetermined value. The frequency division ratio is determined in accordance with the determination result, and the frequency division ratio by the carrier clock generation means is changed according to the determination result.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing a state in which paper sheets are being conveyed. That is, the paper sheet 1 is transported along the transport path 2 by the transport belts 3 and 3. A detector 4 that detects passage of the paper sheet 1 is provided on the transport path 2. As shown in FIG. 3A, the detector 4 outputs a detection signal while the sheet 1 is in correspondence, and is a well-known detector including, for example, a light emitting element and a light receiving element. The conveyor belts 3 are moved by a drive roller (not shown), and the rotational force of a motor (not shown) is transmitted to the drive roller.

FIG. 1 is a block diagram showing the structure of a carrier clock generator which generates a carrier clock in response to a detection signal from the detector 4. That is, the detector 4,
Paper length measuring device 11, reference value setting device 12, comparator 13,
The frequency division ratio setting unit 14, the reference clock generator 15, and the frequency divider 16 are included.

The sheet length measuring device 11 is composed of, for example, a counter, and has a detector 4 as shown in FIG.
3 (b) to FIG. 3 while the detection signal from
The carrier clock supplied from the frequency divider 16 as shown in (d) is counted, and the counting result is output to the comparator 13. In the reference value setting device 12, a count number (the number of carrier clocks corresponding to the length of the sheet 1) as a reference value corresponding to the length of the sheet 1 is set, for example, "6". . The count number from the reference value setting unit 12 is output to the comparator 13.

The comparator 13 compares the count result from the paper sheet length measuring device 11 with the count number from the reference value setting device 12 to change the division ratio when the values do not match. The signal is output to the frequency division ratio setting unit 14.
For example, when the count result from the paper sheet length measuring device 11 is smaller than the count number from the reference value setting device 12 (when the carrier clock is slow), a change signal for increasing the frequency division ratio is output to output the paper sheet. When the count result from the length measuring device 11 is larger than the count number from the reference value setting device 12 (when the carrier clock is fast), a change signal for decreasing the frequency division ratio is output.

The frequency division ratio setting unit 14 outputs a predetermined frequency division value to the frequency divider 16 according to the change signal from the comparator 13. For example, when a change signal for increasing the frequency division ratio is supplied from the comparator 13, the current frequency division value is set to "+1".
When the frequency division value is changed to the updated frequency division value and the change signal for decreasing the frequency division ratio is supplied from the comparator 13, the current frequency division value is changed to "-
1 ”Change to the updated frequency division value.

The reference clock generator 15 is shown in FIG.
The reference clock is generated as shown in FIG. The frequency divider 16 divides the reference clock supplied from the reference clock generator 15 as shown in (e) of FIG. 3 by the frequency division value supplied from the frequency division ratio setting unit 14, and divides this frequency. The signal as shown in FIG. 3B is output to the paper sheet length measuring device 11 and the determination device (not shown) as a carrier clock. In this determination device, a sample of the characteristic data of the paper sheet 1 is obtained by using the supplied carrier clock.

Next, the operation timing of each of the above parts will be described with reference to FIGS. 4 (a) to 4 (g). That is, the paper sheet length measuring device 11 starts the measurement in response to the rise of the detection signal from the detector 4, and ends the measurement in response to the fall of the detection signal from the detector 4 shown in FIG. Upon completion of this measurement, the comparator 13 starts the comparison process and outputs a change signal for this comparison. The frequency division value of the frequency division ratio setting unit 14 updated according to this output is output to the frequency divider 16.

Thus, the period from the rise of the detection signal from the detector 4 to the fall thereof is the measurement period for measuring the length of the paper sheet 1, and the detection signal from the detector 4 is divided from the fall to the frequency division. The carrier clock calculation period is until the value is output. Next, in such a configuration, the operation will be described with reference to the flowchart shown in FIG. That is, when the paper sheet 1 is conveyed on the conveyance path 2 and the leading end of the paper sheet 1 reaches the detection position of the detector 4, the measurement by the paper sheet length measuring device 11 is started and the paper sheet is supplied from the frequency divider 16. Start counting carrier clocks.

When the trailing edge of the paper sheet 1 has passed the detection position of the detector 4, the measurement by the paper sheet length measuring device 11 is completed and the carrier clock supplied from the frequency divider 16 is counted. Upon completion, the counting result is output to the comparator 13. The comparator 13 compares the count result from the paper sheet length measuring device 11 with the count number from the reference value setting device 12, and if the comparison result is the same, the change signal is not output and the frequency divider 16 The carrier clock output from is unchanged.

If the result of the comparison is that the count result from the paper sheet length measuring device 11 is smaller than the count number from the reference value setting device 12, the comparator 13 outputs a change signal for increasing the frequency division ratio. Output to the frequency division ratio setter 14. The frequency division ratio setter 14 changes the current frequency division value to the frequency division value updated by “+1”, and outputs it to the frequency divider 16. The frequency divider 16 divides the reference clock supplied from the reference clock generator 15 by the frequency division value supplied from the frequency division ratio setter 14 into a new carrier clock (becomes faster than the carrier clock at the time of measurement). Is output to the paper sheet length measuring device 11 and the determination device (not shown).

As a result, the carrier clock corresponding to the current carrier speed of the sheet 1 is output from the frequency divider 16. Further, the comparator 13 determines that the paper sheet length measuring device 1
When the count result from 1 is larger than the count number from the reference value setting unit 12, a change signal for decreasing the division ratio is output to the division ratio setting unit 14. The frequency division ratio setter 14 changes the current frequency division value to the frequency division value updated by “−1”, and the frequency divider 16
Output to. The frequency divider 16 divides the reference clock supplied from the reference clock generator 15 by the frequency division value supplied from the frequency division ratio setting unit 14 into a new carrier clock (which is later than the carrier clock at the time of measurement). Is output to the paper sheet length measuring device 11 and the determination device (not shown).

As a result, the frequency divider 16 outputs a carrier clock corresponding to the current carrier speed of the paper sheet 1. As described above, the number of carrier clocks generated while the sheet is detected by the detector is counted, and the count result is compared with the number of carrier clocks corresponding to the length of the sheet. However, the frequency division ratio is determined according to the comparison result, and the number of carrier clocks generated is changed according to the frequency division ratio as the determination result.

As a result, it is possible to generate an accurate transport clock suitable for the transport speed of paper sheets, and an expensive rotary encoder is unnecessary.

[0021]

As described above in detail, according to the present invention,
It is possible to provide an accurate transport clock that matches the transport speed of paper sheets, and to provide a transport clock generator that does not require an expensive rotary encoder.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of a carrier clock generator according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a conveyance state of paper sheets.

FIG. 3 is a diagram for explaining output signals of each unit in FIG.

FIG. 4 is a timing chart for explaining the operation timing of each unit in FIG.

5 is a flowchart for explaining the operation of the carrier clock generation device of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Paper sheet, 2 ... Conveying path, 3, 3 ... Conveying belt, 4 ... Detector, 11 ... Paper sheet length measuring device, 12 ... Reference value setting device, 1
3 ... Comparator, 14 ... Dividing ratio setter, 15 ... Reference clock generator, 16 ... Divider.

Claims (2)

[Claims] 1. A detection unit for detecting a sheet to be conveyed, a reference clock generation unit for generating a reference clock, and a conveyance clock obtained by dividing the reference clock from the reference clock generation unit by a predetermined division ratio. And a counting means for counting the carrier clock generated by the carrier clock generating means while the sheet is being detected by the detecting means, and a counting result of the counting means and a predetermined value. And a changing unit for changing the frequency dividing ratio by the carrier clock generating unit according to the result of the comparison. A carrier clock generator characterized in that. 2. A transporting means for transporting a paper sheet, a detecting means for detecting a paper sheet transported by the transporting means, a reference clock generating means for generating a reference clock, and a reference clock generating means. Carrier clock generating means for generating a carrier clock obtained by dividing the reference clock by a predetermined dividing ratio, output means for outputting the number of carrier clocks corresponding to the length of the paper sheets, and the detecting means for the paper sheets. Counting means for counting the carrier clocks generated by the carrier clock generating means, and comparing means for comparing the count result of the counting means with the number of carrier clocks from the output means. Determination means for determining the frequency division ratio according to the comparison result of the comparison means, and changing means for changing the frequency division ratio by the carrier clock generation means according to the determination result of the determination means, A carrier clock generator characterized by being provided.