JPH03211488A - Automatic adjusting device of detection sensor for paper or the like - Google Patents

Abstract

PURPOSE:To speedily and accurately adjust the operation point of the detection sensor without any operator's intervention by using a voltage, at which a decision result is inverted while the quantity of light emission of a light emission device is made less than usual, as the threshold voltage of a comparator. CONSTITUTION:The light emitting diode 1 of an inspection sensor is supplied with a necessary current from a light emission quantity control means and the light emitted by the diode turns on a phototransistor 2. The voltage which is generated as a result is applied to one input terminal of a comparing means 3 and the variable voltage Vs which is generated by a voltage control means 5 is supplied as the threshold voltage (reference voltage). The comparing means 3 compares them with each other and supplies its comparison result signal to a decision means 4. A control part 6 sends commands to a variable source voltage control means 5 and the light emission quantity control means 7 respectively according to the decision result of the decision means 4.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention automatically adjusts a non-detection sensor for paper sheets used in a paper sheet processing device that processes paper sheets such as banknotes. The present invention relates to an automatic adjustment device that allows automatic adjustment.

[Conventional technology]

2. Description of the Related Art Paper sheet processing devices such as banknote deposit devices used in financial institutions and the like use a large number of detection sensors that detect the presence or absence of paper sheets in order to control the operation of the device. This detection sensor generally has a light emitter and a light receiver facing each other with a path of paper sheets in between.

An example of a paper sheet processing apparatus will be outlined with reference to FIGS. 11 and 12. FIG. 11 is an external view of the paper sheet processing device, and FIG. 12 is a schematic diagram showing its internal structure.

As shown in FIG. 11, a deposit port 11 for taking in banknotes such as deposited banknotes and a withdrawal port 12 for taking out banknotes from the device as needed are provided at the upper front of the paper sheet processing device. ing. On the left and right sides of the upper front of the deposit port 11 and the withdrawal port 12, there are operations that allow two tellers who operate the device to instruct collection processing, withdrawal processing, =I number processing, etc. from both sides of the device. A section 13 is provided. A display section 14 is provided on the front side of each operation section 13, and the display section 14 displays the number of deposited coins, etc., and if necessary, the amount of money. In addition, when an abnormality occurs or the banknotes in the storage section become empty, a message to that effect can be displayed to notify the operator.

As shown in FIG. 12, the internal structure of this device includes a deposit port 11, a withdrawal port 12, a transport section 15, a storage section consisting of a -time storage section 16 and a lower storage section 17, an identification section 19, etc. It is provided as a part.

This paper sheet processing device is capable of various operation modes, but for example, in the case of the deposit kr number mode, the banknotes set in the deposit slot 11 are taken in and conveyed to the recognition section 16a by the conveyance section 13, and then transferred to the recognition section 16a. The denomination and authenticity are determined at step 19a, and after the determination, the conveyance section 15 conveys the denomination to the temporary storage section 16 for the corresponding denomination.

If there is no problem with the identification result in the identification section 19a, the product is stored in the lower storage section 15 provided at the bottom of the temporary storage section 16. When withdrawing money, it is fed out by the feeding roller 18 provided at the bottom of the storage H17, checked by the identification part 19b, and conveyed the required number of coins of the desired denomination to the withdrawal port.
Throw in 2. In addition, in the case of counting mode, deposit port 1
The banknotes set at 1 are conveyed to the recognition section 19a, the denominations of the banknotes are counted to determine whether they are genuine or false, and the banknotes are dispensed to the dispensing port 12 by the conveyance section 15.

Such paper sheet processing apparatuses are generally provided with a large number of detection sensors as shown in FIG. These include, for example, banknote presence/absence detection sensors for deposit port 11 and withdrawal port 2;
These sensors include a sensor for detecting passage of banknotes on the conveyance path, a storage detection sensor for the minus hour storage section 16 and the lower storage section 17, an empty detection sensor for the lower storage section 17, and the like.

Since the characteristics of each component of this detection sensor vary, it is necessary to adjust the detection operating point in order to appropriately determine the presence or absence of banknotes. For this reason, conventionally, the threshold value of 51! J[ is performed for each detection sensor. Furthermore, this adjustment needs to be performed at regular intervals to prevent erroneous recognition due to aging of the sensor or the like.

FIG. 13 is a circuit diagram showing a conventional adjustment of the detection operating point. In this circuit, a phototransistor 2 receives light emitted from a light-emitting diode 1 when a current is applied with a power supply voltage of +Vc, and a voltage generated when the phototransistor becomes conductive is detected by a comparator 3.
Compared with the variable voltage Vs which becomes the threshold voltage (reference voltage) at
The presence or absence of paper sheets is determined by the discriminating means 4 based on the size of the paper sheet, and the operating point is adjusted by adjusting the resistor R connected to the emitter side of the phototransistor to determine the magnitude of the input signal that enters the comparator. , or the reference voltage V that enters the comparator is adjusted by two.

[Problem to be solved by the invention]

However, as mentioned above, these adjustments have to be made one by one by the operator, and paper sheet processing equipment generally has a large number of detection sensors, so it takes a lot of effort to make adjustments. . In addition, it was necessary to readjust the number at regular intervals in consideration of changes over time, which required a great deal of effort. In addition, since the work is done manually, adjustments often occur due to incorrect adjustments.

The present invention was made to solve such problems, and an object of the present invention is to provide an automatic adjustment device that can automatically adjust the operating point of a paper sheet detection sensor.

[Means to solve the problem]

According to the present invention, a paper sheet adjusts the operating point of a detection sensor consisting of a light emitter and a light receiver that receives light emitted from the light emitter and generates a signal depending on the presence or absence of an intervening paper sheet. The automatic adjustment device for a type detection sensor includes: a light emission amount adjusting means for adjusting the light emission amount of the light emitter; a variable power supply voltage control means for outputting a voltage corresponding to a threshold value for a detection operation of the detection sensor; a comparison means for comparing the detection signal with a threshold value adjusted by the variable power supply voltage control means; a determination means for determining passage or presence of a paper sheet based on a comparison result of the comparison means; and a light emission amount adjustment means. The adjustment voltage of the variable power supply voltage is a voltage at which the discrimination result of the discrimination means is reversed when the variable power supply voltage is changed with the amount of light emitted by the light emitter fixed at a predetermined value smaller than normal light emission. The present invention is characterized in that it is equipped with a control section to

[For production]

In the automatic adjustment device according to the present invention, the amount of light emitted from the light emitting device of the detection sensor is reduced by a command from the control device, and the reference voltage applied to the comparator is gradually increased to obtain the discrimination result. The inverted voltage is found and used as the threshold voltage of the comparator. Therefore, the operating point of the detection sensor can be adjusted quickly and accurately without any manual effort.

〔Example〕

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

FIG. 1 is a block diagram showing the basic concept of the configuration of the present invention.

A necessary current is supplied to the light emitting diode 1 of the detection sensor from the light emitting amount control means, and the emitted light thereby makes the phototransistor 2 conductive. The voltage generated thereby is applied to one input terminal of the comparison means 3. On the other hand, the other side input terminal of the comparison means 3 is supplied with a variable voltage V 1 which is a threshold voltage (reference voltage) generated by the variable power supply voltage control means 5 . Therefore, the comparing means 3 compares these and provides a comparison result signal to the determining means 4. Further, the control section 6 gives commands to the variable power supply voltage control means 5 and the light emission amount control means 7, respectively, based on the determination result by the determination means 4.

FIG. 2 is a more specific version of the configuration shown in FIG. 1, and shows a configuration for automating all adjustments and adjustment checks of a paper sheet detection sensor used in a paper sheet processing apparatus.

First, as shown in FIG. 2, the detection sensor is a transmitted light sensor consisting of light emitting diodes 11 to 1o connected in series and phototransistors 21 to 2o whose collectors are commonly connected. The command from the control unit 6 is converted from D to A by the D-A converter 7a, and the analog voltage is converted to V-1 converter 7b.
The light emitting current IF generated from this V-1 converter 7b is applied to the light emitting diodes 1□ to 1n.

In other words, the light emitting diode 1
, ~1o can be controlled. Further, a command is given from the control unit 6 to the D-A converter means 5 as a variable power supply voltage control means, and from there, a command is sent to the normal rotation input terminal of each comparator 3□ to 3o forming the comparison means 3. A voltage (v, 1 to VS□) is given to define those threshold values (VTH). Then, the phototransistor 21 which is the light receiving side of the detection sensor
The detection signal of 2 is inputted as the input signal V1o to the inverting input terminal of the comparators 3, 1 to 3, and the output signal V of the comparators 3 and 3 is inputted as the input signal V1o. ut is input to the control unit 6, and it is determined whether a banknote has passed based on the high level or low level state of this output signal (VoUt). Note that the control unit 6 is controlled by the CPU 8. ROM9a and RA
The determination means 4 shown in FIG. 1 corresponds to the CPU 8 in the actual device, so it is common to the control section 6. Further, an instruction manual means 10 is also connected to the control section 6.

Next, the automatic adjustment operation of the threshold voltage (reference voltage) of the comparator circuit will be explained with reference to the flowchart of FIG. In addition,
Such automatic adjustment of the threshold voltage is performed when adjustment is required due to a sensor error of the passage detection sensor, when the power is turned on, or when an adjustment instruction is given by the instruction input means 1o for periodic adjustment. .

First, the light emitting current IF of the light emitting diode is 2096
The voltage applied to the V-1 converter 7b via the DA converter 7a is controlled based on the command from the control unit 6 so that the voltage is applied to the V-1 converter 7b (step S1). Here, the light emitting current I
The reason why F is set to 20% of the normal value is because the detection output of the detection sensor when detecting the presence of paper sheets (■in=” L) is usually about several percent to 10% of the detection output (Vin""It) when no detection is being performed, so the actual threshold value (VTI
This is to ensure that IL (THI+) falls within the range of ■L and It. In this way, the light emitting current IF
The D-A converter 5 is controlled based on the command from the control unit 6 with the voltage set to 20% of the normal voltage, and the rlJ substation voltage (step S2) is first set to O■, and then gradually raised. Go (step S3), output signal ■. Confirm that uL is inverted (L-H)L (step S4),
When it is reversed, the V at that time is stored in the RAM 9 in the control unit 6.
b (step S5).

Subsequently, an adjustment check is performed to confirm whether or not the value (2) temporarily stored in the RAM 9b is an appropriate value.

First, the control section instructs the D-A converter 5 to fix (2) at the value temporarily stored in the RAM 9b. Then, when ■ is fixed, the light emitting current I of the light emitting diode is
Increase F by a predetermined amount from the normal 20%, and increase the light emitting current IF to, for example, 25% of the normal value, and the manual signal ■1□
(step S6). At this time, it is confirmed that the output signal V is inverted (H-uLL) (step S7). Next, the light emitting current IF is decreased by a predetermined amount to, for example, 18% of the normal light emitting current IF, and the input signal Vln is lowered (step S8
). At this time, the output signal V. , t are inverted (L-H) (step S9). In this way, the threshold value V. 1
After setting 1, as the input signal VIn is raised and lowered,
When the output signal is reliably inverted, the variable power supply voltage V 1 at that time is stored in the RAM 9b as a normal value, and the threshold value adjustment operation is completed. On the other hand, if the output signal V does not perform an inversion operation in the confirmation operation, the ut adjustment operation is restarted from the beginning, and if the adjustment is not possible even after performing 5J adjustment again 0 times (step 511), an adjustment error is detected. Display (step 512) and end J'.

Such adjustment of the detection sensors is performed sequentially for each of the six detection sensors in accordance with a predetermined order.

Next, confirmation of adjustment of the detection sensor will be explained.

Adjustment checks include the adjustment check that is performed immediately after the automatic adjustment of the detection sensor described above, the assembly check (A check) that is performed when the device is assembled, the shipping check (B check) that is performed when the device is shipped, and the device check that is performed immediately after the automatic adjustment of the detection sensor. There are various checks such as an operational check (C-check) that is performed during operation, and each has different adjustment confirmation standards.

These standards are stored in advance in the ROM 9a.

These standards are shown in Figure 5, and in the order of assembly check (A check), shipping check (B check), and series of use checks (C check), the checking standards become looser and the allowable range becomes wider. It is defined as follows.

FIG. 6 is a flowchart showing the operation when checking the adjustment of the detection sensor. Here, the check at the time of adjustment, which is performed after the automatic adjustment is completed, has strict standards because it is performed after the adjustment, and is performed automatically after the adjustment, as already explained with reference to FIG. On the other hand, the assembly check, shipping check, and operation check are performed according to instructions without automatic adjustment. Note that, as described later, the check during operation may be automatically performed when the power is turned on.

First, it is checked whether the power is turned on (step 5).
21) When there is a check instruction (step 522), not when the power is turned on, an interrupt is generated and the mode shifts to adjustment check mode. In this state, input of a check is awaited (step 823), and the type of check is input (step 524).

On the other hand, when the power is turned on and when there is a check instruction but no check type is input, the C check can be automatically set (step 525).

The following setting values differ depending on the type of check, and the type of check is determined in step S31. In the case of A check, the light emitting current IF is set to 29% of the normal value (step 532), and the B
The control unit instructs the D-A converter 7a to set the light emitting current IF to 34% of the normal value (step 533) in the case of a check, and to set the light emitting current IF to 50% of the normal value in the case of a C check (step 534). do. This causes the input signal V, respectively, to rise, and at this time the output signal n, v. It is confirmed that ut is at L level (step 535).

Next, the type of check is determined again in step S36,
In the case of A check, the light emitting current IF is set to 17% of the normal value (step 537), in the case of B check, the light emitting current IF is set to 15% of the normal value (step 538), and in the case of C check, the light emitting current IF is set to 17% of the normal value (step 537). The control unit instructs the D-A converter 7a to set the value to 12% (step 539). At this time, the output signal V is inverted and becomes H level u
t (step 540). When the H level is confirmed in step S40, it is determined that there is no problem with the sensor adjustment check (step 541), and the process ends.

On the other hand, if the predetermined level cannot be confirmed in step S35 and step S40, first check whether the readjustment has been performed n times, which is the limit number of readjustments (step 542), and the number of readjustments has not yet been reached. If not, readjustment is performed (step 543), and if the adjustment is not completed even after n times of readjustment, a sensor error is displayed (step 544) and the process ends.

In this manner, this device can automatically check according to the state of the device using check criteria appropriate to that state.

Next, a comparison circuit for determining the presence or absence of a comparison banknote using the human input signal ■In as a threshold value will be explained using FIG. This comparison circuit compares an input signal with a threshold value, which is a set reference value, and generates an output depending on the magnitude thereof. This comparison circuit is affected by the noise component of the input signal V1n, minute fluctuations of the input signal VIn near the threshold, etc.
The input signal V and the output signal V are adjusted so that the output signal V does not cause malfunction phenomena such as chattering. , 1 are made to have hysteresis characteristics. The width of the dead zone in this hysteresis characteristic is automatically changed to an appropriate value according to the threshold value. Therefore, it is very effective in devices where the threshold value is not determined in advance and is automatically adjusted.

To explain the configuration of this comparison circuit, the voltage V supplied from the variable voltage power supply 3 is passed through the resistor R to the first comparator 1.
It is input as human power VpI to the forward rotation side input terminal of
The output of the second comparator 22 is applied to this input terminal via a resistor R2.

Resistors R and R2 form a voltage divider circuit and divide the variable power supply voltage Vs. Since the input signal V is input to the inverting input terminal of the comparator 21, the output signal V, which is the comparison output, is output from the ]n output terminal. ut is taken out, and the human power V is applied to the normal rotation side input terminal of the comparator 22.
, 2. Further, a power supply voltage +Vc is applied to this output terminal via a resistor R3, and this power supply voltage is divided by a voltage dividing circuit consisting of resistors R4 and R5 connected in series, and the divided voltage is applied to the comparator 22. It is given as the inverting side input terminal input Vn2.

Here, the comparator 22 is an oven in which an open output with an infinite resistance value is generated at the output terminal when the normal input is larger than the inverted input, and a ground output is generated at the output terminal when the normal input is smaller than the inverted input. It forms a collector circuit, and its equivalent circuit is shown in FIG. As shown in the figure, this circuit consists of a differential amplifier made up of transistors Ql-Q6 and an output circuit made up of transistors Q7 and Q8.

The voltage V supplied from the variable voltage power supply is input to the normal input terminal of the first comparator 21 via the resistor R1, and the output of the second comparator 22 is input to this input terminal via the resistor R2.
is given through.

Resistors R and R2 form a voltage divider circuit, and variable power supply 1 Divide the voltage V.

Therefore, the comparator 22 compares the output signal of the comparator 21 with the divided voltage of the power supply (V) and outputs the output signal (Vou
1) is at a high level or a low level, and depending on the result, the output is switched and the threshold value (VV) Tllll' TIIL that is input to the normal input terminal of the comparator 1 is switched.

The operating principle of this comparison circuit is explained below in Figures 7, 9, and 1.
This will be explained with reference to FIG. Now, in FIG. 7, the input signal (Vn,) entering the inverting input terminal of the comparator 21 is greater than the voltage (V pl) entering the normal input terminal.
■+)1), and its output signal is assumed to be in the state of ■-〇. In this state, the normal input terminal of the comparator 22 is -O, and the output of the comparator 22 is at the ground level because the input is larger at the inverted input terminal (vo2>V, ,,). , comparator 1 is required.

As the voltage of the input signal (Vlo) decreases, the output signal changes from L to H.
This is the threshold voltage when the voltage is reversed to . H
Conversely, L is the input signal (V, o
) is smaller than the normal input voltage (V, 1) (Vnl
<Vpl), and its output signal is ■. ut-+v.

Assume that the state is as follows. In this state, the voltages applied to the normal input terminal of comparator 2 are V, 2-+V.

, and there is an inverted input. Therefore, the inverting input terminal is smaller (Vn2<V
, 2), the output of comparator 2 becomes open, and the voltage of V, t-V is applied to the normal input terminal of comparator 1. This voltage is the threshold f! when the output signal is inverted from H to L as the voltage of the input signal (Vln) increases! i voltage v
THtl="s. This situation is shown in FIG. 9 as a hysteresis characteristic.

As mentioned above, the width of the dead zone is determined by the voltage of the 11-variable power supply (V) and the resistance (R1°R2) for setting the threshold voltage.
(') Constant Niyotte is determined, IIJ substation ia (V,
') is in a proportional relationship. Therefore, when the threshold voltage is changed, the width of the dead zone also changes accordingly.
As shown in the figure, when the threshold voltage is lowered to vTl+, the width of the dead zone (E,,') also decreases accordingly,
When the threshold voltage is increased to create "TIE", the width of the dead zone (E,,') also increases accordingly, and the width of the dead zone always changes at a constant ratio to the threshold voltage, and the width of the dead zone is determined to be appropriate. Therefore, in cases where the threshold value is not known in advance, a variable power supply (V
), the width of the dead zone of the hysteresis characteristic (E, ,
), it is possible to always set an appropriate dead zone.

Note that in this example, we explained an inverting comparison circuit, but
Even in a normal comparison circuit in which the inverting input terminal and the normal input terminal are connected in reverse, the width of the dead zone E due to the hysteresis characteristic
11 is similarly determined by the constants of the variable power supply (VS) and the resistors (R, , R2), so a variable width dead zone can be obtained.

As described above, in this paper sheet processing device, all of the large number of detection sensors can be automatically 211fE, and it is also possible to check whether the adjustment has been made properly after adjustment. It is possible to check the adjustment of the detection sensor using appropriate check standards depending on the operation.

In the above embodiment, a comparison circuit is used in which the dead zone due to hysteresis of the input/output characteristics can be automatically changed by the threshold value, but the comparison circuit is not limited to this, and the comparison means may be a simple comparator or a conventionally known Schmidt circuit. - A trigger circuit etc. may be used.

In addition, in the above embodiment, the light emitting current IF was reduced by several percent of the normal value.
~10% is the detection output of banknotes, and the normal 20% in between is used as the threshold standard,
Of course, these values differ depending on the type of sensor and how the sensor is arranged.

In addition, in the above embodiment, the detection sensors are connected in series as shown in FIG. 2 and controlled based on commands from the control button.
The V-1 converters may be connected in parallel to individually control the detection sensors.

〔Effect of the invention〕

As described above, according to the automatic adjustment device for a paper sheet detection sensor according to the present invention, the threshold voltage of the comparator is set to the voltage at which the determination result is reversed when the light emission amount of the light emitter is reduced compared to normal. The SJ! can do.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic concept of the structure of the present invention, Fig. 2 is an explanatory diagram showing the schematic structure of a paper sheet processing device that is a more specific version of the structure of Fig. 1, and Fig. 3 is a comparison diagram. A flow chart explaining the automatic adjustment operation of the threshold voltage (reference voltage) of the circuit, Figure 4 is a graph showing the input/output characteristics of the comparator, Figure 5 is a graph showing the input/output characteristics of the comparator.
6 is a graph showing various criteria for checking the adjustment of the detection sensor, FIG. 6 is a flowchart showing the operation when checking the adjustment of the detection sensor, and FIG. 7 is the input signal Vl. 8 is a detailed circuit diagram of the comparator, FIG. 9 is an explanatory diagram of the dead zone, and FIG. 10 is the dead zone with the configuration of FIG. 7. Fig. 11 is an external view of the paper sheet processing device, Fig. 12 is a schematic diagram of its internal structure, and Fig. 13 shows the conventional adjustment of the detection operating point. It is a circuit diagram. DESCRIPTION OF SYMBOLS 1... Light emitting diode, 2... Phototransistor, 3... Comparison means, 4... Discrimination means, 5... Variable power supply voltage control means, 6... Control part, 7a...D -A
Converter, 7b...V-1 converter, 8...CPU. 9a...ROM. 9b...RAM. 21゜22... Comparator.

Claims (1)

[Claims] A paper sheet that adjusts the operating point of a detection sensor consisting of a light emitter and a light receiver that receives light emitted from the light emitter and generates a signal depending on the presence or absence of an intervening paper sheet. An automatic adjustment device for a type detection sensor, comprising: a light emission amount adjusting means for adjusting the light emission amount of the light emitter; a variable power supply voltage control means for outputting a voltage corresponding to a threshold value for a detection operation of the detection sensor; a comparison means for comparing the detection signal with a threshold value adjusted by the variable power supply voltage control means; a determination means for determining whether or not a paper sheet has passed based on the comparison result of the comparison means; and the light emission amount adjustment means. A voltage at which the determination result of the determining means is reversed when the variable power supply voltage is changed with the amount of light emitted by the light emitter fixed at a predetermined value smaller than normal light emission is set as the adjustment voltage of the variable power supply voltage. An automatic adjustment device for a paper sheet detection sensor, comprising: a control section.