JPH0753094A - Printing device - Google Patents

Abstract

PURPOSE:To detect a double feeding of plural sorts of printing paper sheets with different thicknesses and sizes securely by a single detecting sensor, by detecting a double feeding of printing paper sheets based on a specific data set in a specific character setting means, the feeding current to the detecting sensor, and the light receiving amount to the detecting sensor. CONSTITUTION:A detecting sensor 25 to detect the thickness of printing paper through a light emitter 25a and a light receiver 25b opposing each other on both sides of the printing paper sheets is provided on the way of a feeding route. And in a setting mode at first, the feeding current fed to the light emitter 25a of the detecting sensor 25 is converted, and a specific character data to indicate the relation of the feeding current, the sorts and number of paper sheets, and the light receiving amount is set by utilizing the fact the light receiving amount of the light receiver 25b of the detecting sensor 25 is converted by making the sorts and the number of the printing paper sheets as the parameters. And in an operating mode, a double feeding detecting means detects a double feeding of the printing paper sheets by using the set specific character data, based on the feeding current to a light emitter 25a, and the light receiving amount from the light receiver 25b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer having a plurality of paper cassettes, and more particularly to a printer which detects double feeding of print papers fed from the respective paper cassettes by a single detection sensor. is there.

[0002]

2. Description of the Related Art Recently, in order to issue various certificates such as a resident's card and a seal stamp certificate other than the business hours of city halls and ward offices, they are connected to a host computer that stores various data relating to each of the residents. In addition, a certificate issuing device that is equipped with a printing device capable of high-speed printing and reads the data of the necessary items requested by the applicant from this host computer while printing on a specified paper in a specified form It has been put to practical use.

By the way, in the printing device provided in this certificate issuing device, when issuing various certificates, dedicated printing papers having different thicknesses and sizes are required. It is equipped with a plurality of paper cassettes that respectively store different types of printing paper. Then, at the time of issuing the certificate, when a dedicated print sheet is fed from a specific sheet cassette, in order to detect the double-sheet feeding of the print sheet, that is, the double-feed, in the vicinity of the outlet of each sheet cassette, Each of the light-transmissive detection sensors is provided so that the double-fed printing paper is not issued when the double-feed is detected.

[0004]

However, when a plurality of paper cassettes are provided as in the printing device provided in the certificate issuing device, each of the paper cassettes is provided with a double feed detection sensor. Therefore, there is a problem that the double feed detection mechanism of the printing paper becomes large and complicated, and a space for providing the plurality of double feed detection sensors is required and the cost becomes high. Furthermore, when the type of printing paper stored in the paper cassette is changed, the thickness of the paper is changed, so that it is necessary to adjust the detection level of the double feed detection sensor each time.

The present invention has been made to solve the above-mentioned problems, and can easily and surely detect the double feeding of plural kinds of printing papers having different thicknesses and sizes by using one detection sensor. It is an object of the present invention to provide such a printing device.

[0006]

In order to achieve the above object, a printer according to a first aspect of the present invention, as shown in a functional block diagram of FIG. 1, stores a plurality of types of print sheets having different thicknesses and sizes. A printing apparatus having a paper cassette of No. 1 and feeding a print paper from a selected paper cassette to perform printing by a printing means, and the print paper is sandwiched in the middle of a print paper supply path to face each other. The detection sensor for detecting the thickness of the print sheet through the light emitting section and the light receiving section, and the supply current supplied to the light emitting section of the detection sensor in the setting mode are changed to change the supply current and the print sheet. Characteristic setting means for setting and storing characteristic data indicating the relationship between the type, the number of print sheets, and the amount of received light, the characteristic data set in the characteristic setting means in the use mode, and the light emitting unit of the detection sensor. Based on the amount of received light supply current and a light receiving portion for feeding the received, in which a double-feed detection means for detecting the double feed of the printing paper.

Further, as shown in the functional block diagram of FIG. 2, the printer according to claim 2 has a plurality of paper cassettes for accommodating a plurality of kinds of printing papers having different thicknesses and sizes, and the selected paper cassette. A printing device which feeds printing paper from a printer to perform printing by a printing means, wherein the printing paper is inserted through a light emitting section and a light receiving section which face each other with the printing paper sandwiched in the middle of the printing paper supply path. Sensor for detecting the thickness of the sensor, current changing means capable of changing the supply current supplied to the light emitting portion of the detection sensor, and light receiving amount detecting means for detecting the amount of light received by the light receiving portion of the detection sensor. In the setting mode in which the supply current is set and the threshold value of the amount of received light is set, the amount of received light detected by the received light amount detecting unit is one sheet of printing paper while gradually increasing the supply current through the current changing unit. Receive light only when Setting control means for determining whether or not a predetermined value of the received light amount range is reached, data of a supply current when the received light amount reaches a predetermined value, and a cassette number of a paper cassette are stored in association with each other. In the use mode in which the data storage means and the printing means print on the printing paper, the supply current is set to the supply current corresponding to the cassette number of the paper cassette through the current changing means based on the data from the data storage means. And a double feed detecting means for receiving an output from the received light amount detecting means and detecting whether or not the received light amount is equal to or less than a predetermined value in the use mode.

[0008]

According to the printing apparatus of the present invention having the above-mentioned structure, the detection sensor for detecting the thickness of the printing paper is arranged so as to detect the thickness of the printing paper through the light emitting portion and the light receiving portion which face each other with the printing paper sandwiched therebetween. Since the characteristic setting unit is provided in the middle of the supply path, the amount of light received by the light receiving unit of the detection sensor is changed by changing the supply current supplied to the light emitting unit of the detection sensor in the setting mode. Utilizing the fact that the type and number of print sheets are changed as parameters, characteristic data indicating the relationship between the supply current, the type of print sheet, the number of print sheets, and the amount of received light is set. And the double feed detection means
In the use mode, double feeding of print paper is detected based on the characteristic data set in the characteristic setting means, the supply current supplied to the light emitting portion of the detection sensor, and the amount of light received by the light receiving portion.

As described above, the supply current supplied to the light emitting portion of the detection sensor is changed to set and store characteristic data indicating the relationship between the supply current, the type of print paper, the number of print papers, and the amount of received light. In the use mode, the characteristic data is used to detect the double feeding of the printing paper based on the current supplied to the issuing unit and the amount of light received from the light receiving unit. It is possible to easily and surely detect the double feeding of the printing paper by using one detection sensor.

Further, in the printing apparatus having the above structure, since the detection sensor for detecting the thickness of the printing paper is provided in the middle of the feeding path of the printing paper, the setting control means is provided. In the setting mode in which the supply current is set and the threshold value of the amount of received light is set, while gradually increasing the supply current via the current changing unit capable of changing the supply current supplied to the light emitting unit of the detection sensor, It is determined whether or not the light receiving amount detected by the light receiving amount detecting means for detecting the light receiving amount received by the light receiving unit has reached a predetermined value within the light receiving amount range received only when there is one print sheet. . Then, the data storage means stores the data of the supply current when the amount of received light reaches a predetermined value and the cassette number of the paper cassette in association with each other. On the other hand, in the use mode in which the printing means prints on the printing paper, the current control means makes the supply current corresponding to the cassette number of the paper cassette through the current changing means based on the data from the data storage means. Since the supply current is controlled, the double feed detecting means receives the output from the light receiving amount detecting means in the use mode and detects whether or not the light receiving amount is equal to or less than the predetermined value, that is, whether or not the light receiving amount is in the double feeding state.

As described above, while gradually increasing the supply current supplied to the light emitting portion of the detection sensor, the amount of light received by the light receiving portion of the detection sensor is within the light receiving amount range received only when the print sheet is one sheet. While determining whether or not a predetermined value has been reached,
Since the data of the supply current when the amount of received light reaches a predetermined value and the cassette number are stored in association with each other, the supply current to the light emitting unit is controlled so that the supply current corresponds to the cassette number of the paper cassette. In addition, since the double feed state is detected when the amount of light received falls below a predetermined value, multiple feed of multiple types of printing paper with different thicknesses and sizes can be easily and reliably detected using one detection sensor. It becomes possible to do.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is a case where the present invention is applied to a certificate issuing device that issues various certificates such as a resident's card and a seal stamp certificate. As shown in FIG. 3, the certificate issuing device 1
On the front panel of the main body frame 1a, a CRT display 2 that displays the contents of issued certificates and information to be provided, a numeric keypad 3 housed in a recess, and an ID card (not shown) owned by each user. ) Is sent to the card reader 4 (see FIG. 4), and a call button 5 for calling a person in charge is provided.

On the screen of the CRT display 2 is attached a well-known touch panel 6 in which a plurality of small touch sensors are arranged in a matrix so that a user can input desired information by simply pressing the finger. ing. Also, C
On the front panel on the right side of the RT display 2, a coin insertion slot 7a communicating with the coin sorting device 7 (see FIG. 4) and a bill insertion slot communicating with the bill detecting device 8 (see FIG. 4) for paying the issuing fee. 8a are provided respectively. Further, the front panel is provided with an outlet 9 for taking out change and receipts and an outlet 10 for taking out issued various certificates.

Next, the control system of the certificate issuing device 1 is shown in FIG.
The block diagram of FIG. A drive circuit 30 for driving the card reader 4, a drive circuit 31 for driving the coin sorting device 7, a drive circuit 32 for driving the bill detecting device 8, a drive circuit 33 for driving the laser printer (LP) 11, and a receipt. A drive circuit 34 for driving a journal printer (JP) 12 for printing a certificate, and a drive circuit 35 for driving a stapler 13 for binding the certificates when the laser printer 11 prints a plurality of certificates.
A driving circuit 36 for driving the tallying machine 14 for stamping the certificate, a driving circuit 37 for driving the voice device 15 for outputting an operation explanation regarding the issuance of the certificate by voice, and a CRT.
The CRT controller 38 that drives the display (CRT / D) 2, the ten-key pad 3, the touch panel 6, the call switch 17 linked to the call button 5, and the remote operation panel (R / operation panel) 18 are included in the controller C. Each is connected to the input / output interface 54.

By the way, in the certificate issuing device 1, since special printing paper P is required for issuing various certificates, these three kinds of printing papers P having different thicknesses and sizes are accommodated respectively. It is equipped with three paper cassettes (not shown). Then, in order to individually feed the print paper P stored in each paper cassette, paper feed mechanisms 20 to 22 each including a paper feed roller are attached to each paper cassette, and paper is fed from these paper cassettes. A paper transport mechanism 23 is provided for transporting the printed printing paper P to the laser printer 11 via a supply path (not shown), and a drive circuit 40 for driving these paper feeding mechanisms 20-22.
To 42 and a drive circuit 43 for driving the paper transport mechanism 23 are connected to the input / output interface 54.

Further, the input / output interface 54 includes
It has a mode change switch 24 for switching between a setting mode for setting a threshold value of the amount of received light for detecting the double feeding of the printing paper P and a normal use mode, and a light emitting element 25a and a light receiving element 25b. A voltage change circuit 26 connected to a detection sensor 25 that detects the thickness of the print paper P and a Schmitt trigger TTL 27 are connected to each other.

The controller C is connected to the well-known CPU 52, the input / output interface 54 connected to the CPU 52 via a bus such as a data bus, the RAM 53, and the input / output interface 54 via the hard disk drive controller 51. And a hard disk drive (HDD) 50.

The hard disk drive device 50 has a display drive control program for displaying display data on the CRT display 2, a print drive control program for driving the laser printer 11 and the journal printer 12 to perform print processing, and is specific to the present application described later. A program memory that stores various control programs including the print control control program is provided, and in order to print the character, the outline of the character for each of a large number of characters such as kanji, hiragana, and alphabets is displayed. A font memory in which specified contour line data (outline data) is classified by typeface and stored in correspondence with code data, a pattern in which dot pattern data for displaying each of a large number of characters is stored in correspondence with code data. Data memory etc. It is provided.

In the RAM 53, a supply current pattern memory for storing the number data of the paper cassette and the set supply current pattern data PD in association with each other, and set when the mode changeover switch 24 is switched to the setting mode side ( The flag data of the setting mode flag SF whose data is "0"), the flag memory storing the cassette flags CF1 to CF3 corresponding to the selected cassette numbers 1 to 3, and the calculation result calculated by the CPU 52 are temporarily stored. Various types of memory are provided.

Further, a host computer (HC) 55
In the database, for each of a large number of users to whom an ID card is issued, unique information consisting of various types of data such as a reference number, address, data for seal certification, family register and address for issuing a resident card, etc. is stored in a database. Provided storage device,
The host computer 55 is connected to the input / output interface 54 via a communication device 56. Here, the printing device includes a laser printer 11 and a paper feed mechanism 2.
0-22, paper transport mechanism 23, mode changeover switch 2
4, a detection sensor 25, a current changing circuit 26, a Schmitt trigger 27, a supply current pattern memory of the RAM 53, a flag memory, and the like.

Next, the detection sensor 25, the current changing circuit 26 and the Schmitt trigger 27 will be described with reference to FIG. First, the current changing circuit 26 will be described.
The base of the transistor T1 is connected to the output port OP0 of the input / output interface 54, and the output port O0
The base of the transistor T2 is connected to P1, the base of the transistor T3 is connected to the output port OP2,
The base of the transistor T4 is connected to the output port OP3. The emitter of the transistor T1 is connected via the resistor R1 and the emitter of the transistor T2 is connected to the resistor R1.
2, the emitter of the transistor T3 is connected to the light emitting element 25a via the resistor R3, and the emitter of the transistor T4 is connected to the light emitting element 25a via the resistor R4. Here, the bases of the respective transistors T1 to T4 are connected to the power source via the pull-up resistor r, and the respective transistors T1 to T4 are connected.
The collector of ~ T4 is connected to the power supply.

When the "H" level signal is output from the output port OP0, the transistor T1 becomes conductive,
A current is supplied to the light emitting element 25a via the resistor R1.
Similarly, when the "H" level signal is output from the output port OP1, the transistor T2 is turned on. When the "H" level signal is output from the output port OP2, the transistor T2 is turned on and the output port OP3 is turned on. When the "H" level signal is output from the transistor T4
Are conducted, and the light emitting element 25a is connected through the resistors R2 to R4, respectively.
A supply current I is supplied to. Here, each resistance value is the resistance value of the resistance R1 <the resistance value of the resistance R2 <the resistance value of the resistance R3 <
There is a relationship of the resistance value of the resistor R4.

Next, the light transmission type detection sensor 25 will be described. The detection sensor 25 is provided in the middle of the supply path, and detects the thickness of the print paper P via the light emitting element 25a and the light receiving element 25b which face each other. The light emitting element 25a is composed of a light emitting diode, the light receiving element 25b is composed of a phototransistor, and both elements 25a and 25b are connected in the same manner as a normal detection sensor as shown in the drawing.

Further, the collector of the light receiving element 25b is connected to the input port IP of the input / output interface 54 via the non-inverter type Schmitt trigger 27. That is, when the amount of light received by the light receiving element 25b increases, the signal level from the collector decreases. Here, the Schmitt trigger 27 outputs an "L" level signal when the collector signal level is below the threshold level, and outputs an "H" level signal when the collector signal level exceeds the threshold level.

Next, a print control routine executed by the control device C of the certificate issuing device 1 will be described with reference to the flowcharts shown in FIGS. Incidentally, reference numeral Si in the drawing
(I = 10, 11, 12, ...) Is each step. This control is started when the certificate issuing device 1 is powered on, and when the setting command signal is not input from the remote operation panel (S10: No) and the printing command signal is not input (S11: No). ) And S10 to S11 are repeatedly executed. Then, when the setting command signal is input (S10: Yes), when the setting mode flag SF is set, that is, when the setting mode is set (S14: Yes), the received light amount of each printing paper P is changed. A setting process (see FIG. 7) for setting a threshold value is executed (S1
Five).

When the setting process control is started, a screen for selecting the number of the paper cassette is first displayed on the CRT display 2 (S21). For example, as shown in FIG. 9, a selection screen for selecting three types of paper cassettes or the end of setting is displayed on the CRT display 2. next,
When the desired paper cassette (cassette numbers 1 to 3) is selected via the touch panel 6 (S22) and "End" is not selected (S23: No), the cassette corresponding to the selected cassette numbers 1 to 3 is selected. Only the flags CF1 to CF3 are set (S24).

Next, the set cassette flag C
Paper feed mechanism 20 of paper cassette corresponding to F1 to CF3
A paper feed command is output to 23 (S25). As a result, by the operation of the paper feed mechanisms 20-23 instructed, the print paper P is fed from the paper cassette of the paper feed mechanisms 20-23 to the transport path. Next, "0001" is set as 4-digit pattern data PD consisting of a binary number ("1" or "0") (S26), and this pattern data PD "0001" is set.
Output signals corresponding to the four output ports OP0 to OP3
Is output to (S27). Here, the four numerical values of the pattern data PD “0001” correspond to the four output ports OP0 to OP3 in this order.

That is, when the pattern data PD is "0001", the "H" level signal is output only to the output port OP3. As a result, as shown in FIG. 5, in the current change circuit 26, only the transistor T4 becomes conductive, and
The resistance value of the maximum resistance value R4 itself in the parallel circuit including the one resistor R1 to R4 acts, and the minimum current is supplied to the light emitting element 25a. Therefore, the minimum light emission amount is output from the light emitting element 25a.

Next, the soft timer T provided in the controller C
A predetermined time t (for example, about 2 seconds) is set in M (not shown) to start the operation (S28), and the timer time t
When the time elapses, that is, at the timing when the print paper P is passing the detection sensor 25 (S29: Yes), the signal of the input port IP, that is, the output signal from the Schmitt trigger 27 is read (S30). When the signal at the input port IP is at "H" level, that is, when the collector signal level of the light emitting element 25b is higher than the threshold level of the Schmitt trigger 27 (S31: Yes), one pattern data PD "0001" is present. It is incremented (S32), and when the pattern data PD "0001" is smaller than the maximum value "1111" (S33: No), S27.
~ S33 is repeatedly executed.

For example, the pattern data PD is "000.
When it is "1", the next pattern data PD is "00".
"10" is set, and the "H" level signal is output only to the output port OP2. As a result, as shown in FIG. 5, only the transistor T3 becomes conductive, and the four resistors R1 to R1.
In the parallel circuit of R4, the resistance value of the second largest resistance value R3 itself acts, and the light emitting element 25a
Is supplied with a supply current I that is gradually increased as compared with the case where the resistance value is R4. Therefore, the light emitting element 25a emits a larger amount of light. Similarly, the pattern data PD is “0010” → “0011” → “0101” → “011”.
The supply current I supplied to the light emitting element 25a is gradually increased by sequentially incrementing in the order of "0" → "0111" → ..., The light emission amount from the light emitting element 25a gradually increases.

On the other hand, the supply current I supplied to the light emitting element 25a is gradually increased, the amount of light emitted from the light emitting element 25a increases, and the amount of light received by the light receiving element 25a after passing through the print paper P increases. When the collector signal level of the light receiving element 25b falls and exceeds the threshold level of the Schmitt trigger 27 and the "L" level signal is output from the Schmitt trigger 27 (S31: No), the cassette flags CF1 to CF3 in the set state are set. The cassette number data of the corresponding paper cassette and the pattern data PD at this time are associated and stored in the supply current pattern memory (S3
5) The print paper P supplied to the supply path is discarded through the disposal path (S36), and the process returns to S21. That is, the Schmitt trigger 27 determines whether or not the amount of light received by the light receiving element 25b has reached a predetermined value within the light receiving range in which light is received only when the print sheet P is one sheet.

In the same manner, other cassette numbers are selected (S21, S22) and S23 and subsequent steps are executed. When "End" is selected while the sheet cassette selection screen is displayed (S21, S22, S23: Yes), this control is terminated and the process returns to S10 of the print control. Incidentally, S
If it is determined Yes in 33, it means that the detection sensor 25 or the like has failed, and error processing such as displaying a warning message on the CRT display 2 is executed (S34),
This control is ended and the process returns to S10.

Next, in the print control, when the print command signal is input (S10: No, S11: Yes), when the setting mode flag SF is not set, that is, in the use mode (S12: No), The printing process (see FIG. 8) is executed (S13). When it is determined No in S14 or No in S12, error processing such as displaying an error message indicating that fact on the CRT display 2 is executed (S16), and the process returns to S10.

When this print processing control is started, first, pattern data PD corresponding to the cassette number data commanded at the same time as the print command signal is read from the supply current pattern memory (S41) and corresponds to this pattern data PD. Output signals are simultaneously output to the four output ports OP0 to OP3 (S43). As a result, "H" is output only from the output ports OP0 to OP3 corresponding to the pattern data PD.
The level signal is output, and the light emitting element 25a is supplied with the supply current I corresponding to the cassette number.

Next, similarly to S28 and S29 described above, the process waits until the print sheet P moves to the detection sensor 25 on the way of the supply path (S44, S45: Yes), and the signal from the input port IP, that is, the Schmitt trigger 27. The output signal of is read (S46). As a result, when the signal of the input port IP is at the “L” level, that is, when the print sheet P is one sheet, the attenuation of the light emission amount by the print sheet P is small, and the collector signal level of the light receiving element 25b is the Schmitt trigger 27. When it is lower than the threshold level (S47: No),
Printing is executed by the laser printer 11 (S48),
This control is ended and the process returns to S10 of the print control.

However, when the signal at the input port IP is at the "H" level, that is, when the number of print sheets P is two or more, the amount of light emitted by the print sheets P is greatly attenuated, and the light receiving element 25b.
Is higher than the threshold level of the Schmitt trigger 27 (S47: Yes), the plurality of print sheets P supplied to the supply path are discarded through the discard path (S49), and the error count value EC is 1 Is incremented by one (S50), and when the error count value EC is smaller than "5" (S51: No), S41 and thereafter are executed. When the error count value EC becomes "5" (S51: Yes), there is a possibility that some kind of paper feeding has failed, and error processing such as displaying a warning message on the CRT display 2 is performed. The process is executed (S52), the control is terminated, and the process returns to S10.

By the way, the above embodiment is partially modified,
The relationship between the supply current I and the amount of received light may be set and stored using the type and number of each printing paper P as parameters. That is, as shown in FIG. 10, for example, when the number of print sheets is one, the received light amount characteristic shown by the one-dot chain line when the supply current I is changed, and when the number of print sheets is two, The received light amount characteristic indicated by the two-dot chain line when I is changed is stored in association with the type of the printing paper, and similarly, the received light amount characteristic is also stored for each of the other types of different printing papers. In the use mode, the double feeding of the printing paper may be detected based on the received light amount characteristic for the designated printing paper type, the supply current I and the received light amount at that time. Also in this case, double feeding of printing papers having different thicknesses and sizes can be detected easily and reliably using one detection sensor. Here, when the certificate issuing device is manufactured or used, the light emitting element 2 of the detection sensor 25 is used.
A person may operate the adjusting volume interposed in the supply circuit that supplies the supply current I to 5a to set the received light amount characteristics relating to various sheets and the number of sheets.

As described above, while the supply current I supplied to the light emitting element 25a of the detection sensor 25 is gradually increased, the amount of light received by the light receiving element 25b of the detection sensor 25 is only when the printing paper P is one sheet. While it is determined whether or not a predetermined value in the received light amount range to be received is reached, the data of the supply current I when the received light amount reaches the predetermined value and the cassette number are stored in association with each other. Issuing element 25a so that the supply current I corresponds to the cassette number of the paper cassette
Since the double feed state is detected when the current I supplied to the print sheet is controlled and the amount of received light becomes equal to or less than a predetermined value, the single feed sensor 25 detects the double feed of a plurality of types of printing paper P having different thicknesses and sizes. Can be used to easily and surely detect.
Further, since the threshold value of the amount of received light for the printing paper P fed from the paper cassette is set, even if the type of the printing paper P stored in the paper cassette is changed, the detection level for double feed detection is adjusted. The work can be omitted.

Here, the correspondence relationship between each means described in the claims and the configuration in the above-mentioned embodiment will be explained. The current changing means corresponds to the current changing circuit 26.
The Schmitt trigger 27 corresponds to the received light amount detecting means, the setting control means particularly S27 to S31 of the setting processing control, and the data storing means corresponds to the RAM 53. The supply current pattern memory, which corresponds to the current control means, is particularly S42 to S43 of the print processing control, and the one which corresponds to the double feeding detection means is S44 to S47.

In the setting process control, the pattern data PD when the Schmitt trigger 27 outputs the "L" level signal may be obtained 10 times and the average value thereof may be stored. Further, in the current changing circuit 27, a parallel circuit composed of five or more resistors R having different resistance values may be formed to gradually increase the supply current I at a finer current pitch. Further, the light emitting element 25a of the detection sensor 25 can be configured by a light emitting body that emits infrared rays and other light rays. Then, within the scope of the technical idea of the present invention, various modifications may be made to the control of the embodiment based on the existing technology or the technology obvious to those skilled in the art. Further, it is needless to say that the present invention can be applied to various printing devices including various printing mechanisms and a plurality of paper cassettes.

[0041]

As described above, according to the printing apparatus of the first aspect, the detection sensor, the characteristic setting means, and the double feed detection means are provided, and the supply current supplied to the light emitting portion of the detection sensor is changed. Then, the characteristic data indicating the relationship between the supply current, the type of printing paper, the number of printing papers, and the amount of received light is set and stored. Since the double feed of the printing paper is detected from the characteristic data corresponding to and, it is possible to easily and surely detect the double feed of the plural kinds of printing papers having different thicknesses and sizes by using one detection sensor. . Furthermore, since characteristic data indicating the relationship between the supply current, the type of print paper, the number of print papers, and the amount of received light is set and stored, even if the type of print paper stored in the paper cassette is changed, double feed is performed. The work of adjusting the detection level for detection can be omitted.

According to the printing apparatus of the second aspect, the detection sensor, the current changing unit, the received light amount detecting unit, the setting control unit, the data storing unit, the current control unit, and the double feed detecting unit. Is provided to gradually increase the supply current supplied to the light emitting portion of the detection sensor, and the amount of light received by the light receiving portion of the detection sensor reaches a predetermined value within the light receiving amount range that is received only when there is only one print sheet. While determining whether or not the data has been received, the data of the supply current when the amount of received light reaches a predetermined value and the cassette number are stored in association with each other, so that the supply current corresponds to the cassette number of the paper cassette. Since the double feed state is detected when the current supplied to the issuing unit is controlled and the amount of received light is less than or equal to a predetermined value, it is possible to detect the double feed of a plurality of types of printing paper having different thicknesses and sizes with one detection sensor. Easy and reliable inspection using It can be. Furthermore, since the threshold value of the amount of received light for the printing paper fed from the paper cassette is set, even if the type of printing paper stored in the paper cassette is changed, the detection level adjustment work for double feed detection can be performed. It can be omitted.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the configuration of claim 1.

FIG. 2 is a functional block diagram showing the configuration of claim 2.

FIG. 3 is a perspective view of a certificate issuing device.

FIG. 4 is a block diagram of a control system of the certificate issuing device.

FIG. 5 is a circuit diagram of a voltage changing circuit and a detection sensor.

FIG. 6 is a schematic flowchart of a print control routine.

FIG. 7 is a schematic flowchart of a setting process control routine.

FIG. 8 is a schematic flowchart of a print processing control routine.

FIG. 9 is a view showing an example of a cassette number selection screen.

FIG. 10 is a diagram of a received light amount characteristic showing a received light amount with respect to a change in supply current.

[Explanation of symbols]

 25 detection sensor 25a light emitting element 25b light receiving element 26 current changing circuit 27 Schmitt trigger 50 hard disk drive device 52 CPU 53 RAM C control device

Claims (2)

[Claims] 1. A printing apparatus comprising a plurality of paper cassettes for storing a plurality of types of printing papers having different thicknesses and sizes, wherein the printing papers are fed from the selected paper cassettes and printed by the printing means. A detection sensor for detecting the thickness of the print sheet through a light emitting section and a light receiving section that face each other across the print sheet in the middle of the print sheet supply path; Characteristic setting means for setting and storing characteristic data indicating the relationship between the supply current, the type of print paper, the number of print papers, and the amount of received light by changing the supply current supplied to the light emitting unit, and in the use mode, Double feed detection for detecting double feed of print paper based on the characteristic data set in the characteristic setting means, the supply current supplied to the light emitting portion of the detection sensor, and the amount of light received by the light receiving portion. A printing device comprising means and. 2. A printing apparatus having a plurality of paper cassettes for storing a plurality of types of printing papers having different thicknesses and sizes, wherein the printing papers are fed from the selected paper cassettes and printed by the printing means. A detection sensor for detecting the thickness of the print sheet via a light emitting section and a light receiving section that face each other with the print sheet sandwiched in the middle of the supply path of the print sheet; and a light emitting section of the detection sensor. Current changing means capable of changing the supplied current, light receiving amount detecting means for detecting a light receiving amount received by the light receiving portion of the detection sensor, and setting the supply current and a threshold of the light receiving amount. In the setting mode, while gradually increasing the supply current through the current changing unit, the amount of received light detected by the received light amount detection unit reaches a predetermined value within a received light amount range which is received only when there is one print sheet. did Setting control means for determining whether or not, a data storage means for storing the data of the supply current when the received light amount reaches a predetermined value and the cassette number of the paper cassette in association with each other, and the printing paper by the printing means. In a use mode for printing on, based on the data from the data storage means, through the current changing means, current control means for controlling the supply current so that the supply current corresponds to the cassette number of the paper cassette, A printing apparatus comprising: a multi-feed detection unit that receives an output from the received light amount detection unit and detects whether or not the received light amount is equal to or less than the predetermined value in the use mode.