JP7055296B2 - Optical sensor and counter - Google Patents

Description

The present invention relates to an optical sensor that detects a sheet-shaped object to be detected having a transparent portion at least partially, which is intermittently conveyed to a predetermined position.

When detecting a sheet-shaped object to be detected such as a banknote, for example, a transmissive optical sensor including a floodlight and a light receiver is used. Such an optical sensor includes a determination unit that outputs a determination output, which is a digital signal indicating the presence or absence of an object to be detected, according to the light reception output (see Patent Document 1).

The determination unit is set, for example, with a value indicated by the maximum light receiving output of the light receiver as a reference value, and a value of about half of this reference value as a threshold value. That is, the determination unit outputs a Hi signal indicating that there is no object to be detected when the light receiving output is larger than the threshold value, and a Lo signal indicating that there is an object to be detected when the light receiving output is smaller than the threshold value. Output. On the contrary, the determination unit may be configured to output a Lo signal when there is no object to be detected and to output a Hi signal when there is an object to be detected.

In recent years, there are not only paper bills but also resin bills having a transparent portion. When a banknote having such a transparent portion is detected by an optical sensor, a signal indicating that there is an object to be detected is output even though the banknote is present between the optical sensors.

Therefore, as shown in FIG. 8, the value of the light receiving output when the light passing through the transparent portion is received is higher than the value of the light receiving output when the light passing through the transparent portion is received so as not to be erroneously determined that there is no bill even when the light passing through the transparent portion is received. It is necessary to set the threshold value to a value that is large and smaller than the light receiving output when there is no bill.

However, for example, when the power supply voltage supplied to the light receiver fluctuates and the light receiving output becomes larger than in the normal state, the light received when the light passing through the transparent portion is detected as shown in FIG. The output value may exceed a predetermined threshold. When such a situation occurs, the determination unit outputs a discrimination output indicating that the bill does not exist even though the bill exists between the optical sensors, resulting in an erroneous determination.

JP-A-2015-95023

The present invention has been made in view of the above-mentioned problems, and when a sheet-shaped object to be detected having a transparent portion at least partially transported intermittently is detected, the light receiving output is disturbed by disturbance. It is an object of the present invention to provide an optical sensor capable of preventing erroneous determination due to detection of light passing through a transparent portion even when it fluctuates.

That is, the optical sensor according to the present invention is an optical sensor used for detecting a sheet-shaped object to be detected having a transparent portion at least partially intermittently transported to a predetermined position, and the predetermined position. An LED that emits light to the predetermined position, a light receiving element provided to detect light that has passed through the predetermined position, or light that has passed through the transparent portion of the object to be detected, and the object to be detected at the predetermined position. A reference value setting unit that sets a reference value based on the light receiving output output by the light receiving element when there is no light receiving element, a threshold value setting unit that sets a threshold value based on the reference value, and a value indicated by the light receiving output of the light receiving element. A determination unit that outputs a digital determination output indicating whether or not the object to be detected is present based on the magnitude relationship between the light and the threshold value is provided, and the reference value setting unit is located at the predetermined position of the object to be detected. It is characterized in that it is configured to update the reference value when there is no such reference value.

In such a case, the reference value setting unit updates the reference value when the object to be detected is not present at the predetermined position, so that, for example, a fluctuation in the power supply voltage occurs and the light receiving output of the light receiving element is increased. Even if it fluctuates, the reference value is changed accordingly, and the threshold value can also be changed.

Therefore, even if the light receiving output when the light passing through the transparent portion of the object to be detected is detected by the light receiving element is larger than that in the normal state, the threshold value is not exceeded so that the object to be detected is described. It is possible to prevent the determination unit from outputting an erroneous determination by outputting a determination output indicating that the object to be detected is not present even though the position is in a predetermined position.

For example, a threshold value that is smaller by a predetermined percentage with respect to the value of the maximum light receiving output output from the light receiving element is always maintained, and the threshold value is sequentially set according to the fluctuation of the light receiving output when there is no object to be detected. To enable the change, when the reference value setting unit outputs a determination output indicating that the object to be detected does not exist at the predetermined position, the light receiving output output by the light receiving element is output. Anything may be used as long as the reference value is updated to the value of.

When the light receiving output fluctuates to the extent that an erroneous judgment does not occur in the judgment output regarding the presence or absence of the detected object of the judgment unit, the threshold value is changed so that the consistency of the judgment criteria can be maintained. In order to do so, the light receiving output fluctuates only slightly, and the value indicated by the light receiving signal output by the light receiving element when the object to be detected is not present at the predetermined position by the reference value setting unit, and the above. The reference value may be updated only when the absolute value of the difference from the reference value is smaller than the predetermined value.

To enable the determination unit to output a determination output indicating that the object to be detected is present at the predetermined position even when the light passing through the transparent portion of the object to be detected is detected by the light receiving element. The threshold value setting unit is configured to set the threshold value so as to be larger than the value indicated by the light receiving output when the light receiving element detects the light transmitted through the transparent portion of the object to be detected. Just do it.

When it is possible to provide an analog external output as a reference for determining the presence or absence of the object to be detected in addition to the digital determination output output from the determination unit, and there is a light receiving output of light passing through the transparent unit. However, in order to make it easier to set a threshold value for the external output, the reference for the light receiving output when the light receiving element detects light that has passed through the transparent portion based on the light receiving output of the light receiving element. It suffices if it is further provided with an external output generator that generates an analog external output in which the amount of decrease with respect to the value is enlarged.

In such a case, for example, it is assumed that the value of the light receiving output when there is no object to be detected and the value of the light receiving output when the light passing through the transparent portion of the object to be detected is detected are close to each other. However, it is possible to widen the interval between the values of the external output corresponding to those cases. Therefore, when setting a separate threshold value for the analog external output, it is possible to select a value sufficiently distant from the value in each case, and even if there is a fluctuation in the external output, erroneous judgment is less likely to occur. Can be done.

In order to match the maximum light receiving output of the light receiving element with the maximum external output so that the range of the threshold value that can be set with respect to the external output is less likely to fluctuate, the external output generating unit may be used with the light receiving element. When the value indicated by the light receiving output of is the reference value, the value indicated by the external output may also be one that generates the external output so as to indicate the reference value.

Depending on the transparency of the transparent part of the object to be detected, for example, the value of the external output when passing through the transparent part can be set to be about half of the maximum output so as to be shielded from the object to be detected. In order to facilitate accurate determination by separating the value of the external output when the object is to be detected and the value of the external output when there is no object to be detected at approximately equal intervals, the external output generation unit may be used. A coefficient that determines the magnification of the reduction in the light receiving output with respect to the reference value when the light passing through the transparent portion is detected by the light receiving element is accepted as an external input, and an external output corresponding to the accepted coefficient is generated. It should be.

In order to accurately determine the presence or absence of the object to be detected by reflecting the change in the amount of decrease in the light receiving output to the external output even when the light receiving output of the light receiving element fluctuates. When the reference value setting unit receives an external input for updating the reference value, the reference value may be updated to the value of the light receiving output output by the light receiving element.

An optical sensor according to the present invention, a transport mechanism that intermittently conveys the object to be detected to a predetermined position, a detection number output unit that outputs the number of detected objects to be detected based on the output of the optical sensor, and a detection number output unit. For example, it is possible to configure an automatic payment machine or the like that can accurately count resin bills or the like having a transparent portion if the counter is provided with the above.

Further, an optical sensor according to the present invention, a transport mechanism that intermittently conveys the object to be detected to a predetermined position, and an abnormality determination unit that determines a transfer abnormality of the object to be detected based on the output of the optical sensor. If the transport device is provided with a

As described above, according to the optical sensor according to the present invention, since the reference value is updated based on the light receiving output of the light receiving element when the object to be detected is not detected, the power supply voltage or the like fluctuates and the light receiving output However, the threshold value can be changed as appropriate even if the voltage fluctuates as compared with the normal time. Therefore, when the light that has passed through the transparent portion is received, the light receiving output exceeds the threshold value, and the determination unit outputs a determination output indicating that the object to be detected is not present even though the object to be detected is in a predetermined position. It can be prevented from being stored.

The schematic perspective view which shows the optical sensor which concerns on 1st Embodiment of this invention. The schematic circuit diagram of the receiver in 1st Embodiment. The functional block diagram of the optical sensor of 1st Embodiment. The flowchart which shows the operation of the optical sensor of 1st Embodiment. The functional block diagram of the optical sensor of the 2nd Embodiment. The schematic diagram which shows the relationship between the received light output and the external output of the optical sensor of 2nd Embodiment. The flowchart which shows the operation of the optical sensor of 2nd Embodiment. A schematic graph showing a case where an erroneous judgment occurs due to a fluctuation in power supply voltage in a conventional optical sensor.

The optical sensor 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

The optical sensor 100 of the first embodiment is used to configure a counter or an automatic payment machine that counts the number of resin banknotes such as Australian dollars, which is a sheet-shaped object to be detected TG having a transparent portion TG1. ..

This counter has a transport mechanism (not shown) that intermittently transports banknotes to a predetermined position, and whether or not the banknotes are in a predetermined position based on the difference between the presence or absence of shielding by the banknotes by emitting light to the predetermined position. It is provided with an optical sensor 100 for detecting the above, and a detection number output unit (not shown) for outputting the detected number of banknotes based on the output of the optical sensor 100. The details of the optical sensor 100 will be described below.

As shown in FIG. 1, the photosensor 100 is a transmissive type and includes a photodetector 1 and a photodetector 2 provided so as to receive the light emitted from the light projector 1 so as to be opposed to each other. Is.

In the first embodiment, the floodlight 1 includes an LED 11. The floodlight 1 is arranged so that the light emitted from the LED 11 passes through a predetermined position in the transport path of the bill to be detected TG.

The light receiving device 2 includes, for example, a light receiving element 21 such as a photodiode or a phototransistor, and a microcomputer MC that determines the presence or absence of a detected object TG based on the output of the light receiving element 21. The light receiving element 21 and the microcomputer MC form a circuit as shown in FIG.

The light receiving element 21 detects light when the detected object TG is not in a predetermined position or has passed through the transparent portion TG1 of the detected object TG, and outputs a voltage which is a light receiving output according to the radiation intensity of the light. .. Hereinafter, the light receiving output when the object to be detected TG is not at a predetermined position is referred to as a first light receiving output, and the light receiving output when the light passing through the transparent portion TG1 is detected is referred to as a second light receiving output. Here, the characteristics of the object to be detected TG will be described. The value of the second light receiving output can be, for example, 50% or more and 90% or less based on the value of the first light receiving output.

The microcomputer MC includes an A / D converter, a D / A converter, a memory, a CPU, and the like, and determines whether or not the object to be detected TG exists at a predetermined position based on the light receiving output of the light receiving element 21. Then, a determination output, which is a digital signal indicating the determination result, is output. Specifically, in the microcomputer MC, a program for the optical sensor 100 stored in the memory is executed, and various devices cooperate with each other, so that at least the output acquisition unit 22 and the reference value setting unit 23 are shown in FIG. It functions as a threshold value setting unit 24 and a determination unit 25. The details of each part will be described below.

The output acquisition unit 22 samples the light receiving output of the light receiving element 21 which is an analog signal at a predetermined sampling cycle, converts it into a digital value, and calculates the average value thereof. In the first embodiment, the output capture unit 22 captures the received light output n times and calculates the average value V1. Unless otherwise specified in the following description, the light receiving output includes not only a single light receiving output but also an average value V1 output from the output capturing unit 22.

The reference value setting unit 23 sets a reference value Vo used for setting a threshold value for determining the presence / absence of the detected object TG based on the average value V1 output from the output acquisition unit 22, and averages them. When the value V1 changes by a predetermined amount, it is updated to a new value. Here, the reference value Vo is a value set based on the light receiving output output by the light receiving element 21 when there is no object to be detected TG at a predetermined position. In other words, the reference value Vo is set to the maximum output or a value in the vicinity thereof that is output when the optical sensor 100 is not shielded from light in the environment where the optical sensor 100 is installed. The configuration and operation related to the update of the reference value Vo by the reference value setting unit 23 will be described later.

The threshold value setting unit 24 sets a value obtained by multiplying the reference value Vo by a predetermined constant as a threshold value. In the first embodiment, the predetermined constant is a predetermined value larger than 0 and 1 or less, and is fixed at, for example, 0.95. The threshold value is T, the predetermined constant K, the value A of the light receiving output when the object to be detected TG does not exist at the predetermined position, and the value of the light receiving output when the light passing through the transparent portion TG 1 is detected by the light receiving element 21. When B is set, the threshold value is set so that B ≦ T = Vo × K ≦ A. As can be seen from the above equation, when the reference value Vo is updated in the reference value setting unit 23, the threshold value T is also updated accordingly. That is, a value smaller by a predetermined ratio of the reference value Vo is set as the threshold value T. In the first embodiment, the predetermined constant K is multiplied by the reference value Vo, but for example, the threshold value T may be set by subtracting the predetermined constant K from the reference value Vo.

The determination unit 25 outputs a digital determination output indicating whether or not the object to be detected TG is present or present, based on the magnitude relationship between the value indicated by the light receiving output of the light receiving element 21 and the threshold value. That is, the determination unit 25 compares the average value V1 calculated from the output acquisition unit 22 with the set threshold value T, and if the average value V1 is larger than the threshold value T, it is detected at a predetermined position. The judgment output Hi indicating that there is no object TG is output. On the other hand, when the average value V1 is equal to or less than the threshold value T, the determination unit 25 outputs a determination output Lo indicating that the object to be detected TG is present at a predetermined position.

In the first embodiment, for example, even if the power supply voltage connected to the receiver 2 fluctuates, the light passing through the transparent portion TG1 of the object to be detected TG is in a predetermined position when the light receiving element 21 is detected. The reference value Vo and the threshold value T are updated so that the determination unit 25 outputs the determination output Lo indicating the presence of the detected object TG.

Specifically, the reference value setting unit 23 is a case where the determination unit 25 outputs a determination output Hi indicating that the object to be detected does not exist at a predetermined position, and the average value V1 of the light receiving output at that time is output. When the absolute value of the difference between and the reference value Vo is smaller than the predetermined value, the average value V1 at that time is updated as a new reference value Vo. That is, when the light receiving output detected between the intermittently transported TGs to be detected is smaller than ± 1% of the set reference value Vo, the next TG to be detected is transported. The light-receiving output output by the light-receiving element 21 in the absence of the immediately preceding object to be detected TG is set to a new reference value Vo.

Further, when the reference value Vo is updated to a new value, the threshold value setting unit 24 multiplies the reference value Vo by a predetermined constant K and updates the reference value Vo to the new threshold value T. That is, when the characteristics of the light receiving output fluctuate due to fluctuations in the power supply voltage or the like, the reference value Vo is updated in accordance with the fluctuations. Then, when the reference value Vo is changed, the threshold value T is updated so that the ratio is maintained, so that the value of the threshold value T itself is appropriately changed.

The detection operation of the object to be detected TG of the optical sensor 100 configured in this way will be described with reference to the flowchart of FIG.

When the power of the optical sensor 100 is turned on, the output capture unit 22 captures the light receiving output of the light receiving element 21 n times and calculates the average value V1 (step S1). At the time of this activation, the reference value setting unit 23 sets the average value V1 calculated by the output acquisition unit 22 as the reference value Vo without determining the presence or absence of the detected object TG. Further, the threshold value setting unit 24 sets a value obtained by multiplying the set reference value Vo by a predetermined coefficient K as the threshold value T (step S2).

When the initial setting is completed, the determination operation regarding the presence / absence of the detected object TG and the update operation of the reference value Vo are started. That is, the output capture unit 22 captures the light receiving output of the light receiving element 21 n times and calculates the average value V1 (step S3).

Next, the determination unit 25 compares the newly calculated average value V1 with the threshold value T, which is a value obtained by multiplying the reference value Vo by, for example, 0.95, which is a predetermined constant K (step S4).

Here, when the average value V1 is smaller than the threshold value T, the determination unit 25 outputs a determination output Lo indicating that the object to be detected TG is present (step S5). When the step S5 is reached, the reference value Vo is not updated, but the process returns to step S3, and the determination operation regarding the presence / absence of the detected object TG at the predetermined position is repeated.

On the other hand, when the average value V1 is larger than the reference value Vo, the determination unit 25 outputs a determination output Hi indicating that there is no detected object TG (step S6). In this case, it is determined whether or not to update the reference value Vo (step S7).

For example, when the current average value V1 is included within, for example, 1% above and below the current reference value Vo, the process returns to step S2, and the reference value setting unit 23 sets the current average value V1 as a new reference value. Update as Vo. On the other hand, if the average value V1 is not included within, for example, 1% above and below the current reference value Vo, and for example, if a large difference occurs for some reason, the reference value Vo is not updated and step S3. The determination operation of the object to be detected TG is repeated as it is.

If there is an external input from the user to update the reference value Vo before the operation from step S4 to step S7 is performed, the operation from step S4 to step S7 is not performed immediately at that time. The reference value setting unit 23 may be configured so that the reference value Vo is updated by the average value V1 of the above.

As described above, according to the optical sensor 100 of the first embodiment, the light receiving output characteristics of the light receiving element 21 change due to fluctuations in the power supply voltage, and the light receiving output that is output changes even if the same amount of light is received. If so, the reference value Vo is updated to a new value with the average value V1 while the detected object TG is not detected. Then, since the threshold value setting unit 24 always multiplies the same predetermined coefficient K by the reference value Vo to set the threshold value T, the same threshold value T is updated every time the reference value Vo is updated.

That is, the difference in the absolute value within the predetermined value of the average value V1 of the light receiving output in the state where the detected object TG is intermittently conveyed and in the absence of the detected object TG is based on the reference value Vo at that time. If it occurs, the value of the reference value Vo is updated with the average value V1 at that time.

Further, since the threshold value T is always maintained at a value that reflects fluctuations in the power supply voltage and the like, the threshold value T can be set to exceed the received light output even when light that has passed through the transparent portion TG1 is received. Therefore, it is possible to prevent the determination output Lo, which indicates that there is no detection, from being erroneously output from the determination unit 25 when the light that has passed through the transparent unit TG1 is received.

Next, the optical sensor 100 according to the second embodiment of the present invention will be described with reference to FIGS. 5 to 7. The same reference numerals are given to the parts corresponding to the parts described in the first embodiment.

The optical sensor 100 of the second embodiment is configured so that the light receiving output of the light receiving element 21 used for determining the presence or absence of the detected object TG can be output as an analog output to the outside. That is, as shown in FIG. 5, the microcomputer MC is configured to realize a function as an external output generation unit 26 that outputs an analog output by a D / A converter.

The external output generation unit 26 does not output the light-receiving output output from the light-receiving element 21 as it is as an external output, but corrects the light-receiving output to a form suitable for detecting the object to be detected TG and externally. Output to.

That is, as shown in the schematic diagram of FIG. 6, the external output generation unit 26 is an analog in which the amount of decrease in the light receiving output with respect to the reference value Vo when the light receiving element 21 detects the light passing through the transparent unit TG1 is expanded. Produces an external output of. Specifically, when the light receiving output of the light receiving element 21 is used as it is as an external output, the maximum light receiving output output by the light receiving element 21 and the transparent portion TG1 when there is no object to be detected TG as shown in FIG. 6 (b). The difference from the light receiving output of the light receiving element 21 when the light passing through the light receiving element 21 is detected is small. This is because when the light that has passed through the transparent portion TG1 is detected, a light receiving output larger than about half of the maximum light receiving output is generated. Therefore, the light receiving output itself has the presence of the object to be detected TG, the light passing through the transparent portion TG1 is detected, and the light is completely shielded by the printing portion or the like. It cannot be evenly reflected as a difference in light reception output. Therefore, when the light receiving output itself is an external output, a threshold value is set between the maximum output and the output when passing through the transparent portion TG1 with respect to this external output, and the presence or absence of the detected object TG is determined. When trying to make a judgment, the range in which the threshold value can be set is very limited, and it is not easy to use.

In order to solve such a problem, the external output generation unit 26 has a case where the light passing through the transparent unit TG1 is detected by the light receiving element 21 as can be seen by comparing FIGS. 6 (a) and 6 (b). The external output of is expanded to be about half of the maximum light receiving output.

Further, the external output generation unit 26 is configured to accept a coefficient for determining the magnification of the reduction amount as an external input, and how much the reduction amount of the light receiving output with respect to the reference value Vo is expanded to be an external output. Can be set as appropriate. It should be noted that this magnification is set in advance before the determination operation and the update operation are started, and is not changed during the operation.

In addition, when the light receiving output of the light receiving element 21 fluctuates when there is no object to be detected TG due to fluctuation of the power supply voltage or the like, the reference value Vo is updated and the light passing through the transparent portion TG1 is detected. The light receiving output is configured to always be maintained at a predetermined ratio with respect to the maximum output.

Next, the operation of the optical sensor 100 of the second embodiment will be described with reference to the flowchart shown in FIG.

When the power of the optical sensor 100 is turned on, the output capture unit 22 captures the light receiving output of the light receiving element 21 n times and calculates the average value V1 (step ST1).

At the time of this activation, the reference value setting unit 23 sets the average value V1 calculated by the output acquisition unit 22 as the reference value Vo without determining the presence or absence of the detected object TG. When the predetermined condition is satisfied except for the first time, the reference value Vo is updated based on the average value V1 of the light receiving output at that time (step ST2).

When the initial setting is completed, the operation of the external output generation unit 26 is started. That is, the output capture unit 22 captures the light receiving output of the light receiving element 21 n times and calculates the average value V1 (step ST3).

Next, the external output generation unit 26 starts the calculation of the difference output V2 (step ST4). Specifically, the external output generation unit 26 subtracts the value obtained by multiplying the reference value Vo by the coefficient A (0≤A≤1) preset by the external input from the average value V1 of the received light output as the differential output V2. Calculate the value (step ST5). Next, the external output generation unit 26 determines whether or not the difference output V2 is 0 or more (step ST6). When the difference output V2 is 0 or more, the calculated value is maintained as it is (step ST7), and when the difference output V2 is smaller than 0, the difference output V2 is treated as 0 (step ST8).

When the calculation of the difference output V2 is completed, the external output generation unit 26 calculates the external output Vout based on the difference output V2 and the coefficient A. Specifically, the external output generation unit 26 calculates Vout = V2 × {1 / (1-A)} = (V1-Vo × A) × {1 / (1-A)} as an external output, and the external output is calculated. The voltage indicating the value is output as an analog signal (step ST9). Here, when V1 = Vo, Vout = V1 and the light receiving output and the external output have the same value. On the other hand, when the average value V1 of the light receiving output is smaller than the reference value Vo and the difference output V2 is larger than 0, the amount of decrease in the light receiving output is expanded and the external output Vout smaller than the average value V1 of the light receiving output is output. Will be done. The light receiving output and the external output do not have to be set to the same value, and may be set to have different values.

Next, when there is an external input for updating the reference value Vo in order to adjust the external output Vout by the user, the reference value setting unit 23 updates the reference value Vo with the average value V1 at that time ( Step ST10).

When there is no external input, the reference value setting unit 23 determines whether or not the object to be detected is TG (step ST11). When there is a detected object TG, the reference value setting unit 23 repeats the generation of the external output without updating the reference value Vo. On the other hand, when there is no object to be detected TG, the reference value setting unit 23 determines whether or not the difference between the average value V1 and the reference value Vo is within a predetermined range. When the difference is within a predetermined range, the reference value setting unit 23 updates the reference value Vo to the acquired average value V1 (step ST12). On the other hand, when the difference is out of the predetermined range, the reference value setting unit 23 does not update the reference value Vo.

In the case of the optical sensor 100 of the second embodiment configured in this way, the presence or absence of the detected object TG having the transparent portion TG1 is determined as compared with the case where the light receiving output of the light receiving element 21 is analog output as it is. An external output suitable for determination can be output as an analog signal.

That is, if it is a light receiving output, the difference in the light receiving output is small between the case where there is no light receiving object TG and the case where the light passing through the transparent portion TG1 is detected by the light receiving element 21, and the range in which the threshold value can be set becomes small. On the other hand, in the case of the external output of the optical sensor 100 of the second embodiment, the detected object TG exists as the value of the external output when the light passing through the transparent portion TG1 is detected by the light receiving element 21. It can be halved with respect to the value of the external output when it is not set, and the threshold value can be easily set.

Other embodiments will be described.

In the above embodiment, the case where the optical sensor according to the present invention is used as a counter for detecting the number of objects to be detected has been described as an example, but the optical sensor may be used for other purposes. For example, an optical sensor according to the present invention, a transport mechanism that intermittently transports an object to be detected to a predetermined position, an abnormality determination unit that determines a transport abnormality of the object to be detected based on the output of the optical sensor, and an abnormality determination unit. It may be configured as a transport device provided with. In such a case, even if the object to be detected having a transparent portion causes a transport clogging at the detection position of the optical sensor and an abnormality occurs, there is no object to be detected and the transport clogging occurs. It is possible to distinguish and judge.

The object to be detected whose presence or absence is determined by the optical sensor according to the present invention is not limited to the resin banknote, and may be a sheet-like object having another transparent portion. For example, the presence or absence of the transparent film that is intermittently conveyed may be detected by an optical sensor.

The output from the optical sensor may be an output in which a determination output, which is a digital signal indicating the presence or absence of an object to be detected, and an external output, which is an analog signal, are simultaneously output in parallel.

The optical sensor of each embodiment was a so-called transmissive optical sensor, but a floodlight and a light receiver were provided on the same side with respect to the object to be detected, a reflection mirror was placed on the opposite side, and light was emitted from the floodlight. It may be configured as a retroreflective type optical sensor that determines the presence or absence of an object to be detected based on whether or not the light is reflected by the reflection mirror and detected by the light receiver.

The microcomputer for determining the presence or absence of the object to be detected may be provided in the floodlight instead of being provided in the light receiver, and may be wired so that the output of the light receiving element can be transmitted into the floodlight.

In addition, a part of various embodiments may be combined or modified as long as it does not contradict the gist of the present invention.

100 ... Optical sensor 1 ... Floodlight 11 ... LED
2 ・ ・ ・ Receiver 21 ・ ・ ・ Light receiving element 22 ・ ・ ・ Output acquisition unit 23 ・ ・ ・ Reference value setting unit 24 ・ ・ ・ Threshold setting unit 25 ・ ・ ・ Judgment unit 26 ・ ・ ・ External output generation unit TG・ ・ ・ Detected object TG1 ・ ・ ・ Transparent part

Claims (9)

An optical sensor used to detect a sheet-shaped object to be detected having a transparent portion at least partially, which is intermittently conveyed to a predetermined position.
An LED that emits light to the predetermined position and
A light receiving element provided so as to detect light that has passed through the predetermined position or light that has passed through the transparent portion of the object to be detected.
A reference value setting unit that sets a reference value based on the light receiving output output by the light receiving element when the object to be detected is not present at the predetermined position.
A threshold setting unit that sets a threshold value based on the reference value,
A determination unit that outputs a digital determination output indicating either the presence or absence of the object to be detected based on the magnitude relationship between the value indicated by the light receiving output of the light receiving element and the threshold value is provided.
When the reference value setting unit does not have the object to be detected at the predetermined position while the object to be detected is intermittently conveyed to the predetermined position.
When the absolute value of the difference between the value indicated by the light receiving signal output by the light receiving element and the reference value is smaller than the predetermined value, the reference value is updated.
An optical sensor characterized in that the reference value is not updated when the absolute value of the difference between the value indicated by the light receiving signal output by the light receiving element and the reference value exceeds the predetermined value. When the reference value setting unit outputs a determination output indicating that the object to be detected does not exist at the predetermined position, the reference value setting unit updates the reference value to the value of the light receiving output output by the light receiving element. The optical sensor according to claim 1. A claim in which the threshold value setting unit is configured to set the threshold value so as to be larger than the value indicated by the light receiving output when the light receiving element detects the light transmitted through the transparent part of the object to be detected. Item 1. The optical sensor according to item 1. An external output generator that generates an analog external output in which the amount of decrease in the light receiving output with respect to the reference value when the light passing through the transparent portion is detected by the light receiving element is enlarged based on the light receiving output of the light receiving element. The optical sensor according to claim 1, further comprising. The fourth aspect of claim 4, wherein the external output generation unit generates the external output so that the value indicated by the external output also indicates the reference value when the value indicated by the light receiving output of the light receiving element is the reference value. Optical sensor. The external output generation unit accepts as an external input a coefficient for determining the magnification of the reduction amount of the light receiving output with respect to the reference value when the light receiving element detects the light passing through the transparent unit, and uses the accepted coefficient. The optical sensor according to claim 4, wherein the corresponding external output is generated. The optical sensor according to claim 1, wherein when the reference value setting unit receives an external input for updating the reference value, the reference value is updated to the value of the light receiving output output by the light receiving element. The optical sensor according to any one of claims 1 to 7.
A transport mechanism that intermittently transports the object to be detected to a predetermined position,
A counter including a detection number output unit that outputs the detection number of the object to be detected based on the output of the optical sensor. The optical sensor according to any one of claims 1 to 7.
A transport mechanism that intermittently transports the object to be detected to a predetermined position,
A transport device including an abnormality determination unit for determining a transport abnormality of the object to be detected based on the output of the optical sensor.

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