JP2007106556A - Medium detection device and printer - Google Patents

Abstract

A medium detection device capable of preventing erroneous detection of a medium such as printing paper and a printer including the medium detection device are provided.
A detector 8 having a light-emitting element 8a and a light-receiving element 8b, a light-emitting element 9a and a light-receiving element 9b, and disposed so as to face the detector 8 with a print paper 4 to be detected. A detector 9 is provided, and the printing paper 4 is detected by detecting whether the light emitted from the light emitting element 8a of the detector 8 is transmitted or reflected by the light receiving elements 8b and 9b. The light emitting element 8a of the detector is arranged to face the light receiving element 9b of the detector 9, and the light emitting element 9a of the detector 9 is arranged not to face the light receiving element 8b of the detector 8. .
[Selection] Figure 2

Description

The present invention relates to a medium detection device for detecting a medium such as a label, a receipt, and printing paper having a preprint, and a printer including the medium detection device.

Conventionally, a printer that prints on a label affixed to a roll (band) mount has an upstream side in the transport direction with respect to the print position for control of transporting the label to a print position and printing it at a predetermined position. A paper detection device (medium detection device) is disposed on the label to detect the position of the label (see Patent Document 1). Since the paper detection device supports a plurality of types of printing paper (medium), as shown in Patent Document 2, there are two detectors in which a light emitting element (light emitting part) and a light receiving element (light receiving part) are paired. However, it is mentioned that they are arranged at positions facing each other through the printing paper. Further, Patent Document 1 discloses that when a printed label is discharged from a printer separately from the paper detection device,
A label discharge detecting device for checking whether or not the operator has removed the label is provided near the label discharge port.

In particular, a paper detection apparatus having a configuration referred to in Patent Document 2 will be described in more detail with reference to FIG. FIG. 7A is a cross-sectional view showing a configuration of a conventional paper detection device and detection of printing paper. FIG. 7B is a cross-sectional view showing detection when there is no printing paper. The paper detection device 50 arranges the same reflection type detectors as a detector 54 and a detector 55 via a printing paper 53 in which a label 52 is attached to a mount 51. The detector 54 and the detector 55 respectively have light emitting elements 54a and 55a that emit light and light receiving elements 54b and 55b that receive light. The light emitting element 54a and the light receiving element 55b face each other, and the light emitting element 55a and The light receiving element 54b is disposed to face the light receiving element 54b. A light emitting element 54 a of the detector 54 and a light receiving element 55 b of the detector 55.
Are combined to form a transmission detector. Moreover, both the detector 54 and the detector 55 can be used as a reflection detector. In the case of printing paper having a preprint, in consideration of the appearance of the surface to be printed, preprinting is often performed on the back surface of the printing paper. The same applies to the printing paper 53 in which the label 52 is pasted on the mount 51. Here, the detector 54 is used as an original reflection detector so as to detect from the back surface of the printing paper 53. Of course, if there is a preprint on the surface of the printing paper 53, the detector 55 can be used as a reflection detector to perform the same operation.

When used as a transmission detector, the light emitting element 54 a of the detector 54 emits light, and the emitted light can pass through the mount 51 of the printing paper 53 (transmitted light P), and the light receiving element 55 of the detector 55.
b is reached. On the other hand, the mount 51 and the label 5 are attached to the portion where the label 52 is attached.
Since 2 overlaps, almost no light can be transmitted. Therefore, the position of the label 52 on the mount 51 can be recognized based on the change in the output of the light receiving elements 55b. by the way,
A part of the light emitted from the light emitting element 54a is reflected although there is a slight difference in any of the portions where the mount 51 and the label 52 are attached. Accordingly, the light-emitting element 5 of the detector 54.
The light receiving element 54b of the detector 54 also senses the reflected light Q of 4a. At this time, if there is a preprint on the back surface of the mount 51, the light emitted from the light emitting element 54a is absorbed by the preprinting portion, so that the reflected light Q disappears and the light receiving element 54b does not sense the light. Therefore, these light receiving elements 5
Based on the output change of 5b, the position of the preprint on the back surface of the mount 51 can be recognized. If there is a preprint on the back surface of the mount 51, the light does not pass through the light receiving element 55 b of the detector 55. In this case, the light receiving element 55b cannot distinguish whether it is sensing the part to which the label 52 is attached or pre-printing. Therefore, when there is a preprint, the detector 54 is used as a reflection detector.

When the printing paper 53 is not loaded in the printer or the printing paper 53 is no longer consumed, the reflected light Q does not exist even if the printing paper 53 is transported for a predetermined length. The element 54b does not sense light, and the transmitted light P is continuously sensed by the light receiving element 55b of the detector 55. In this way, depending on the combination of the detector 54 and the detector 55, the state of the print paper 53 at the position of the paper detection device 50 is only the mount 51, the mount 51 and the label 52, or there is a preprint. It is possible to detect whether the printing paper 53 is present or not. The detection operation for distinguishing the printing paper 53 is:
The initial operation may be performed when there is a possibility that a different type of printing paper 53 is loaded, such as when the power is turned on or when the printing paper 53 is loaded. This is because after the type of the printing paper 53 can be specified, only the combination detection device may be used in accordance with the type of the printing paper 53. In this configuration, the light emitting element only needs to be included in the detector 54.
By making the detector 54 and the detector 55 the same detector having the light emitting elements 54a and 55a and the light receiving elements 54b and 55b, the characteristics of light emission and light reception can be matched, and no special adjustment or the like is required. It is. Furthermore, it is effective in terms of reduction of parts types, ease of procurement and handling of detectors, and ease of detection control due to the same detector.

JP 2004-181887 A JP-A-5-332717

However, in the conventional technique, as shown in FIG. 7B, when there is no printing paper 53 at the position of the paper detection device 50, the light leakage R or the like dispersed from the light emitting element 54a of the detector 54 is detected by the detector 55.
May be reflected by the surface of the light emitting element 55a, and the light receiving element 54b of the detector 54 may sense the reflected light. In this case, there is a problem that the paper detection device 54 erroneously detects that the print paper 53 is present even though the print paper 53 is not present.

In order to solve the above-described problems, an object of the present invention is to provide a medium detection device capable of preventing erroneous detection of a medium such as printing paper and a printer including the medium detection device.

The medium detection device of the present invention includes a first detector having a light emitting part and a light receiving part, and a second detector having a light emitting part and a light receiving part, and arranged with respect to the first detector via a medium. And detecting the medium by detecting the light emitted from the light emitting unit of the first detector with the light receiving unit of the first or second detector, the light emitting unit of the first detector is The light detector of the second detector is disposed at a position facing the light receiving section of the second detector, and the light emitting section of the second detector is disposed at a position not facing the light receiver of the first detector. To do.

According to this medium detection device, when light from the light emitting unit of the first detector passes through the medium, the light receiving unit of the second detector senses the transmitted light, and from the light emitting unit of the first detector. Is reflected by the medium, the reflected light is sensed by the light receiving unit of the first detector. The presence or absence of the medium can be detected based on the result of sensing light from the light emitting unit of the first detector by the light receiving unit of the first detector and the light receiving unit of the second detector. In this case, the light emitting unit of the second detector reflects light leaked from the light emitting unit of the first detector, and the reflected light is received by the light receiving unit of the first detector, causing erroneous detection. In order to prevent this, it is arranged so as not to face the light receiving portion of the first detector. If it carries out like this, even if it reflects by the light emission part of a 2nd detector, and light emission part itself light-emits, it will not be detected by the light-receiving part of a 1st detector. In this way, by a simple procedure of arranging the position where the light emitting unit of the second detector is arranged so as not to face the light receiving unit of the first detector, the medium related to the light emitting unit of the second detector False detection can be almost prevented.

The printer of the present invention includes a medium detection device, and the medium is a medium for printing.

According to this printer, the medium detection device is provided. When the light from the light emitting portion of the first detector passes through the medium, the medium detection device senses the transmitted light by the light receiving portion of the second detector. When the light from the light emitting unit of the first detector is reflected by the medium, the light receiving unit of the first detector senses the reflected light. The presence or absence of the medium can be detected based on the result of sensing light from the light emitting unit of the first detector by the light receiving unit of the first detector and the light receiving unit of the second detector. In this printer, the light emitting unit of the second detector reflects the light leaked from the light emitting unit of the first detector, and the reflected light is received by the light receiving unit of the first detector to perform erroneous detection. So as not to occur,
It is the arrangement | positioning which does not oppose the light-receiving part of a 1st detector. If it carries out like this, even if it reflects by the light emission part of a 2nd detector, and light emission part itself light-emits, it will not be detected by the light-receiving part of a 1st detector. As described above, the second detector for the medium mounted on the printer can be simply arranged so that the position where the light emitting unit of the second detector is arranged is not opposed to the light receiving unit of the first detector. It is possible to substantially prevent erroneous detection related to the light emitting unit.

In addition, the medium detection device has no function and medium for distinguishing and detecting, as a medium, a printing paper with a label attached to a belt-like mount or a printing paper for a slip and a printing paper having a preprint. It is preferable to have a function of detecting

According to this configuration, in addition to the function of detecting whether or not a medium is loaded, the printer further detects that the medium is loaded. Whether the sheet is a sheet or a printing sheet having a preprint printed for position detection is distinguished and detected. The printer can identify the medium to some extent and reduce the burden of checking the medium in the user's print preparation.

And when detecting a medium with a medium detection apparatus, it is made to light-emit from the light emission part of a 1st detector, and is not made to light-emit from the light emission part of a 2nd detector.

According to this configuration, in order to detect the medium, it is set to emit light only from the light emitting part of the first detector, and the light receiving part is not provided so as to face the light emitting part of the second detector. In addition to measures to suppress the effects when the light emitting part of the detector emits light, the erroneous detection of the medium is prevented more reliably by stopping the light emitting part of the second detector from emitting light. It is possible.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Embodiments of the invention will be described below with reference to the drawings. In the embodiment, a thermal head that prints on a printing paper with a label attached to the mount or roll paper, and a paper detection device that can detect the label and the mount of the printing paper, and a medium such as roll paper separately. A printer having a (medium detection device) will be described as an example.
(Embodiment)

FIG. 1 is a schematic diagram showing an outline of a printer according to an embodiment of the present invention. The printer 1
A thermal head that accommodates a roll unit 5 around which a printing paper 4 having a label 3 attached to a belt-like mount 2 is wound inside the main body of the printer 1 and prints on the label 3 of the printing paper 4 drawn from the roll unit 5. 6, an opening / closing lid 18 that can be opened and closed for mounting the roll unit 5, and a peeling unit 13 that is closed so as to overlap the closed opening / closing lid 18.

The opening / closing lid 18 presses the printing paper 4 against the thermal head 6 when the opening / closing lid 18 is closed, and rotates the platen roller 7 that conveys the printing paper 4, and the upstream of the printing paper 4 in the conveyance direction with respect to the platen roller 7. And a detector (first detector) 8 provided on the side for detecting the printing paper 4. A detector (second detector) 9 is provided on the main body side of the printer 1 so as to face the detector 8 with the printing paper 4 interposed therebetween, and the detector 8 and the detector 9 are a paper detection device. (Media detection device) 10 is formed. Further, the opening / closing lid 18 is provided with the platen roller 7.
, A peeling roller 11 for rapidly changing the transport direction of the printing paper 4 so that the label 3 is peeled from the mount 2, and a transport for transporting the mount 2 whose transport direction has been changed. And a roller 12.

The peeling unit 13 passes through the peeling unit 13 so that the pressing roller 14 for pressing the mount 2 against the transport roller 12 to smoothly transport the mount 2 and the label 3 peeled from the mount 2 are discharged. A label discharge port 15 provided on the outer surface side of the printer 1 of the label discharge port 15 and capable of manual cutting of the printing paper 4 when necessary, and a label provided facing the label discharge port 15. And a label detector 19 for detecting the presence or absence of 3. Between the opening / closing lid 18 and the peeling unit 13, a mount discharge port 1 for discharging the mount 2.
7 is formed. The printer 1 also includes a control unit 20 that comprehensively controls detection, conveyance, printing, and the like of the printing paper 4 in the printer 1.

In the printer 1 having such a configuration, mounting of the printing paper 4, printing on the label 3, and peeling of the label 3 will be described in detail. First, the printing paper 4 is loaded when the opening button (not shown in FIG. 1) is pressed and the opening / closing lid 18 is open, and the roll portion 5 of the printing paper 4 is loaded inside the printer 1. Next, the printing paper 4 is pulled out from the roll unit 5 and the opening / closing lid 18 is closed.

When the open / close lid 18 is closed, the platen roller 7 presses the printing paper 4 between the platen roller 7 and the thermal head 6 so as to contact the thermal head 6. At this time, the printing paper 4 is guided from the roll unit 5 to the thermal head 6 through the detector 8 and the detector 9, and further drawn out of the printer 1 through the peeling roller 11. Platen roller 7 and transport roller 12
Meshes with a drive device (not shown) linked to a conveyance motor (not shown), and the rotation of the conveyance motor can be transmitted to the platen roller 7 and the conveyance roller 12. The platen roller 7 and the transport roller 12 are configured to synchronize their rotations in order to transport the printing paper 4 in cooperation.

In this state, the printing paper 4 is wound around the peeling roller 11 so that the peeling unit 13
Close. By closing the peeling unit 13, a sensor (not shown) senses the closed state of the opening / closing lid 18 and the peeling unit 13, and the printer 1 is ready for printing. When the peeling unit 13 is closed and the printer 1 is ready for printing, the platen roller 7 and the conveyance roller 12 are rotated by driving the conveyance motor, and the printing paper 4 sandwiched between the platen roller 7 and the thermal head 6. Is conveyed, and the label 3 to be printed first is sent to a printable position.

Here, the process of sending the label 3 to the print start position will be briefly described. The position of the label 3 is detected by using a detector 8 and a detector 9 provided in the conveyance path of the printing paper 4. The detector 8 and the detector 9 are arranged so as to face each other with the printing paper 4 interposed therebetween, and detect the mount 2 and the label 3 by detecting the light transmittance and reflectance of the printing paper 4. . The printing paper 4 is composed of a portion of the label 3 and the mount 2 and a portion of only the mount 2, and the mount 2 and the label 3.
Is different in light transmittance and reflectance from each other, and using these differences, it is possible to detect only the mount 2 (hereinafter referred to as between labels). From the position where this label was detected,
By feeding a predetermined amount of paper, the label 3 is conveyed to a position where printing on the label 3 is started. Details will be described later with reference to FIG.

Next, peeling of the label 3 printed by the thermal head 6 will be described. FIG. 1 shows an outline of the printer 1, and at the same time, after the peeling unit 13 is closed, the label 3 is conveyed to the thermal head 6 by the rotation of the platen roller 7 to perform printing. It is shown that the conveyance is stopped by the amount of. After the label 3 is printed by the thermal head 6, the label 3 is conveyed along with the mount 2 toward the peeling roller 11. Then, the mount 2 is bent at the peeling roller 11 so as to be wound around the peeling roller 11 to change the transport direction, and is guided to the mount discharge port 17 by the transport roller 12 that rotates in synchronization with the platen roller 7.

When the mount 2 changes the transport direction in the peeling roller 11, the label 3 attached to the mount 2 also tries to change the transport direction following the mount 2, but the mount 2 is bent sharply. , Peel off from the mount 2 without being able to follow. The peeled label 3 is discharged toward the label discharge port 15 on the extended line connecting the thermal head 6 and the peeling roller 11. The label 3 after printing is conveyed by a predetermined amount based on position information between labels detected before conveyance to the printing start position or position information between labels detected during printing. It is conveyed to the stop position.

In this case, the label detector 19 detects the presence / absence of the label 3 discharged from the label discharge port 15. The label 3 remains attached to the mount 2 by the end of the label 3 that has not been peeled off from the mount 2, and the peeled portion is discharged from the label discharge port 15 toward the outside of the printer 1. The label 3 discharged from the label discharge port 15 can be easily peeled off from the mount 2, and is taken out from the printer 1 and used as a label on which predetermined printing has been performed. When the label 3 is removed and the label 3 is no longer detected by the label detector 19, the printer 1 determines that the label 3 has been removed and determines that printing on the next label 3 is possible. Then, printing on the next label 3 is executed. In addition, if a fluorine resin or the like is applied to the label discharge port 15, it is possible to prevent the sticking surface of the label 3 from sticking to the label discharge port 15.

Next, the paper detection device 10 will be described. FIG. 2 is a cross-sectional view showing the configuration of the sheet detection apparatus according to the embodiment of the present invention. The paper detection apparatus 10 includes a detector 8 provided on the opening / closing lid 18 and a detector 9 provided on the main body side of the printer 1. The detector 8 includes a light emitting element (light emitting part) 8a such as a photo LED (Light Emitting Diode) that emits light, and a light receiving element (light receiving part) 8b such as a phototransistor that senses light. Like the detector 8, the detector 8 has a light emitting element (light emitting part) 9a and a light receiving element (light receiving part) 9b.

The detector 8 and the detector 9 are disposed so as to face each other with the printing paper 4 interposed therebetween so that the light receiving element 9b of the detector 9 senses the light emitted from the light emitting element 8a of the detector 8. The light emitted from the light emitting element 8 a is substantially orthogonal to the printing paper 4. On the other hand, the light emitting element 9a of the detector 9 is disposed so as to be the farthest from the light receiving element 8b of the detector 8. In this case, the light for detecting the printing paper 4 is emitted by the light emitting element 8a of the detector 8, and the light emitting element 9a of the detector 9 does not emit light. That is, although the light emitting element 9a is not necessary, using the same detector as the detector 8 and the detector 9 reduces the number of parts, facilitates procurement of the detector, and the printer due to the same detector. 1 is effective and effective in terms of the ease of detection control and the like in 1.

Such detection of the printing paper 4 by the paper detection device 10 is performed when light emitted from the light emitting element 8 a passes through the printing paper 4 and is detected as transmitted light P by the light receiving element 9 b of the detector 9 or reflected by the printing paper 4. Has been sensed as reflected light Q by the light receiving element 8b of the detector 8, or
The detection result of whether the light receiving element 8b and the light receiving element 9b both sensed or not sensed and the characteristics of the printing paper 4 are inquired. That is, a transmission detector is configured by combining the light emitting element 8a of the detector 8 and the light receiving element 9b of the detector 9, and the light emitting element 8a of the detector 8;
A reflection detector is configured by combining the light receiving element 8b of the detector 8. Detected printing paper 4
The identification will be described later with reference to FIGS. 4 and 5.

When the printing paper 4 is not mounted, the light from the light emitting element 8a is detected most directly as the transmitted light P by the light receiving element 9b. At this time, even if there is light leakage R from the light emitting element 8a and it is reflected by the light emitting element 9a of the detector 8, there is no light receiving element 8b facing the light emitting element 9a, so the light leakage R is detected by the light receiving element 8b. There is almost nothing to do. Therefore, it is possible to almost completely prevent erroneous detection of the conventional printing paper 4 described with reference to FIG.

Next, main media that can be detected by the paper detection device 10 will be described. FIG. 3 shows typical media, (a) is a perspective view showing a printing paper with a label affixed to a mount, and (b) is a perspective view showing a ticket having a preprint, (C) is a perspective view showing a roll paper for receipt printing. The medium shown in FIG. 3A is a typical example of the medium shown in FIG.
The printed paper 4 shown in FIG. 4 is printed with labels 3 attached to the belt-like mount 2 at equal intervals. The paper detection device 10 detects between labels based on the light transmission and reflection relationship between the mount 2 and the label 3, and the printer 1 accurately conveys the label 3 to the thermal head 6 and the peeling roller 11 based on the detection result. Is possible.

The medium shown in FIG. 3B is a ticket (printing paper) 21 for a concert or the like, and the tickets 21 are continuous in a strip shape with the cutout portion 22 as a boundary. In this case, the ticket 21 is the printer 1
The performance date, venue, seat number, etc. are printed by the thermal head 6 and the label outlet 1
5 is discharged. After the discharge, the tickets 21 are cut one by one or after a predetermined number of prints, the cut portion 22 is cut by the cutter 16 and delivered to the customer. Each ticket 21 includes a ticket 21.
For the position detection, a preprint 23 that does not transmit and reflect light is printed and provided on the light emitting element 8a side of the detector 8 of the ticket 21. When the paper detection device 10 detects the preprint 23, each ticket 21 is accurately conveyed to the printing position on the thermal head 6 and the cutting position on the cutter 16 based on the position where the preprint 23 is detected. Is possible.

The medium shown in FIG. 3C is a so-called roll paper for printing a customer purchase and issuing a receipt (printing paper) 25. When printing the receipt 25, the paper detection device 10
When the presence or absence of roll paper is detected, and the installation of roll paper is detected, the roll paper is conveyed by a predetermined length in the direction of the thermal head 6 and printing on the roll paper is started. After printing, the cutting unit 26 is conveyed to the position of the cutter 16. Thereafter, the receipt 25 is sequentially printed on the roll paper.

4A and 4B show detection of the medium shown in FIG. 3 by the paper detection device 10, wherein FIG. 4A is a cross-sectional view showing detection of a printing paper mount, and FIG. 4B shows detection of a printing paper label. Sectional view, (c
) Is a cross-sectional view showing detection of a preprint. 4A shows that the paper detection device 10 is shown in FIG.
The case where the mount 2 of the printing paper 4 shown in (a) is detected is shown. Usually, the mount 2 to which the label 3 is attached has a property of transmitting and reflecting light emitted from the light emitting element 8a of the detector 8. Therefore, the transmitted light P emitted from the light emitting element 8 a and transmitted through the mount 2 is detected by the light receiving element 9 b of the detector 9. At the same time, the reflected light Q emitted from the light emitting element 8 a and reflected by the mount 2 is detected by the light receiving element 8 b of the detector 8. As described above, since the light receiving element 8b and the light receiving element 9b of the paper detection device 10 respectively detect the reflected light Q or the transmitted light P, the printer 1 is mounted and detected on the printing paper 4. It can be determined that it is the mount 2.

FIG. 4B shows a case where the paper detection device 10 detects the label 3 of the printing paper 4 shown in FIG. In the case of detecting the label 3, the label 3 and the mount 2 to which the label 3 is attached are detected together. Usually, the label 3 affixed to the mount 2 has a property of reflecting the light emitted from the light emitting element 8a of the detector 8 while hardly transmitting the light. Therefore, the transmitted light P emitted from the light emitting element 8 a and transmitted through the label 3 is minimal, and the light receiving element 9 of the detector 9.
b is a level at which nothing is detected. At the same time, the reflected light Q emitted from the light emitting element 8 a and reflected by the label 3 and the mount 2 is detected by the light receiving element 8 b of the detector 8.
Thus, the transmitted light P is not detected by the light receiving element 9b of the detector 9, and the light receiving element 8b of the detector 8 is detected.
Since the reflected light Q is detected, the printer 1 can determine that the label 3 of the printing paper 4 is mounted and detected.

The roll paper for the receipt 25 shown in FIG. 3C also has a property of transmitting almost no light emitted from the light emitting element 8a of the detector 8 but reflecting it, like the label 3. The transmitted light P is not detected by the light receiving element 9b, and the reflected light Q is detected by the light receiving element 8b of the detector 8.

FIG. 4C shows a case where the sheet detection apparatus 10 detects the ticket 21 having the preprint 23 shown in FIG. Preprint 2 printed on ticket 21
3 has the property of not transmitting and reflecting light emitted by the light emitting element 8a of the detector 8. Accordingly, there is no transmitted light P emitted from the light emitting element 8a and transmitted through the ticket 21 and reflected light Q reflected by the ticket 21, and the light receiving elements 8b and 9b do not detect anything. Thus, since the transmitted light P and the reflected light Q are not detected, the printer 1 can determine that the ticket 21 having the preprint 23 is mounted and detected.

Note that the preprint 23 can be used not only for detecting the position of the ticket 21 but also for detecting the position of the coupon or the label 3.

Next, in the medium shown in FIGS. 3 and 4, the identification of the medium based on the detection results of the light receiving element 8 b of the detector 8 and the light receiving element 9 b of the detector 9 will be described. FIG. 5 is a matrix diagram showing the detection intensities of the reflection detector and the transmission detector with respect to the medium. Detector 8 and detector 9
Each of the light receiving elements 8b and 9b shows the detected intensity of the transmitted light P or the reflected light Q detected by each medium in a matrix. H represents that the detection intensity is strong, and L represents that the detection intensity is weak or no light is received. The medium can be specified from the combination of H and L.

First, when there is no medium, almost all the light emitted by the light emitting element 8a of the detector 8 is received by the light receiving element 9b of the detector 9. Therefore, the detection intensity of the light receiving element 9b is H. on the other hand,
Since the reflected light Q does not exist, the detection intensity of the light receiving element 8b of the detector 8 is L without light reception. From the combination of the light receiving element 9b being H and the light receiving element 8b being L, it can be determined that the printer 1 is not loaded with the printing paper 4 or the like.

In the case of the detection of the mount 2, since the transmitted light P and the reflected light Q exist, both the light receiving element 9b and the light receiving element 8b are H. In the case of the detection of the label 3, since the transmitted light P is hardly present and the reflected light Q is mainly present, the light receiving element 9b is L and the light receiving element 8b is H.

In the case of detecting the receipt 25, the transmitted light P is hardly present and the reflected light Q is mainly present, so that the light receiving element 9b is L and the light receiving element 8b is H. In this case, the detection result is the same as the detection result of the label 3, but the intensity of the reflected light Q detected by the light receiving element 8 b when detecting the receipt 25 and the detection of the light receiving element 8 b when detecting the label 3. If the intensity can be detected by comparison, the receipt 25 can be detected separately from the label 3.

Furthermore, in the case of detection of the preprint 23, since both the transmitted light P and the reflected light Q do not exist, both the light receiving element 9b and the light receiving element 8b are L. As described above, the light receiving elements 8b and 9b of the paper detection device 10 detect the transmitted light P and the reflected light Q in the mount 2, label 3, receipt 25, preprint 23, and the like. It is possible to specify the medium as described above, or determine whether there is no medium.

Next, the configuration of the control unit 20 that controls the printer 1 will be described. FIG. 6 is a block diagram mainly showing the control unit of the printer. The control unit 20 creates a document to be printed by the printer 1 and temporarily transmits a communication interface 31 for connecting to the host computer 30 that transmits the print data as print data, and print data sent from the host computer 30. A RAM (Random Access Memory) 32, a medium storage unit 34 storing types of printing paper 4 and receipts 25 that the printer 1 can handle, a light receiving element 8 b shown in FIG.
A detection matrix storage unit 35 storing a matrix for medium detection by 9b, a ROM (Read Only Memory) 33 having a program for controlling the printer 1, and various types based on the program stored in the ROM 33 CPU that executes the function (Centra
l Processing Unit) 36.

In addition, the control unit 20 controls the thermal head 6 to execute printing and print control unit 3.
7, a transport control unit 38 for controlling a transport motor 39 for driving the platen roller 7 and the transport roller 12, a detector 8 having a light emitting element 8a and a light receiving element 8b, and a light emitting element 9a
And a detection management unit 40 for managing the detection result of the detector 9 having the light receiving element 9b.

Communication interface 31, RAM 32, ROM 33, CP constituting these control units 20
The U 36, the print control unit 37, the conveyance control unit 38, and the detection management unit 40 are connected to each other via the bus 41 and function as the printer 1.

In the above, the embodiment of the sheet detection apparatus 10 embodying the present invention has been described. The effect of this embodiment is described collectively.

(1) Since the paper detection device 10 provided in the printer 1 is arranged so that the light emitting element 9a of the detector 9 that detects the transmitted light P does not face the light receiving element 8b of the detector 8, the light emission of the detector 9 There is no case where the element 9a reflects the light leakage from the light emitting element 8a of the detector 8 and the reflected light is received by the light receiving element 8b of the detector 8. As a result, when the printing paper 4 is not loaded and detection by the light receiving element 8b is not performed, it is possible to substantially prevent the light receiving element 8b from detecting light reception and erroneously detecting that the printing paper 4 is present.

(2) By disposing the light emitting element 9a of the detector 9 at a position farthest from the light receiving element 8b of the detector 8, light leakage etc. reaches the light emitting element 9a of the detector 9 and is reflected and sensed by the light receiving element 8b. It is possible to prevent almost completely.

(3) Whether the mount 2 of the printing paper 4 is detected in addition to the detection of whether or not the printing paper 4 or the receipt 25 is mounted by detecting the transmitted light P and the reflected light Q by the two light receiving elements 8b and 9b. Alternatively, whether the label 3 is detected can be easily identified with reference to the detection matrix stored in the ROM 33.

(4) By setting the light emitting element 9a of the detector 9 so as not to emit light, the light emitted from the light emitting element 9a of the detector 9 leaks out of the setting direction and is detected by the light receiving elements 8b and 9b. It is possible to prevent the erroneous detection caused by it.

In addition, the present invention is not limited to the above-described embodiment, and the following modifications can be given.

(Modification 1) In FIG. 2, the arrangement of the detector 8 and the detector 9 may be interchanged with respect to the printing paper 4. The function as the paper detection device 10 is not changed, and the printer 1
The degree of freedom of arrangement is improved.

(Modification 2) In FIG. 2, the light emitted from the light emitting element 8a of the detector 8 is not substantially orthogonal to the printing paper 4, but may be emitted obliquely by tilting the light emitting element 8a. The light receiving element 9b of the detector 9 is also tilted so as to receive light. Even with such an arrangement, the transmitted light P
Further, by detecting the reflected light Q, the printing paper 4 can be detected as in the embodiment.

(Modification 3) The light receiving element 8b and the light receiving element 9b not only detect the presence or absence of light reception, but also detect the detected intensity of the transmitted light P and reflected light Q, that is, the printing paper 4 or the like from the difference in light transmittance and reflectance. It may be detectable. In this way, even if the label 3 and the receipt 25 have the same combination of the presence or absence of light reception by the light receiving element 8b and the light receiving element 9b, each can be specified by the difference in detection intensity.

(Modification 4) The printer 1 is not limited to the thermal method of printing on the thermal label 3 or the like,
A thermal method using an ink ribbon, a dot impact method, an ink jet method, or the like may be used. Use other than thermal paper is possible, and the types of printers 1 on which the paper detection device 10 can be mounted can be expanded.

1 is a schematic diagram showing an outline of a printer according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a configuration of a paper detection device according to an embodiment of the present invention. (A) The perspective view which shows the printing paper with which the label was affixed on the mount. (B) The perspective view which shows the ticket which has a preprint. (C) The perspective view which shows the roll paper for receipt printing. (A) Sectional drawing which shows the detection of the mount of printing paper. (B) Sectional drawing which shows the detection of the label of a printing paper. (C) Sectional drawing which shows the detection of a preprint. The matrix figure which shows the detection intensity of the reflection detector with respect to a medium, and a transmission detector. FIG. 2 is a block diagram mainly showing a control unit of the printer. (A) Sectional drawing which shows the structure of the conventional paper detection apparatus, and the detection of printing paper. (B) Sectional drawing which shows the detection when there is no printing paper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Mount, 3 ... Label, 4 ... Printing paper, 6 ... Thermal head, 7 ... Platen roller, 8 ... Detector as 1st detector, 8a, 9a ... Light emitting element as light emission part,
8b, 9b ... light receiving element as light receiving unit, 9 ... detector as second detector, 10 ... paper detecting device as medium detecting device, 11 ... peeling roller, 12 ... conveying roller, 13 ... peeling unit, 14 ... Pressing roller, 19 ... Label detector, 20 ... Control unit, 23 ... Preprint, 3
DESCRIPTION OF SYMBOLS 0 ... Host computer, 32 ... RAM, 33 ... ROM, 36 ... CPU, 37 ... Print control part, 38 ... Conveyance control part, 40 ... Detection management part, P ... Transmitted light, Q ... Reflected light, R ... Leakage light.

Claims (4)

A first detector having a light emitting portion and a light receiving portion;
A second detector having a light emitting portion and a light receiving portion, and arranged with respect to the first detector via a medium,
Detecting the medium by detecting light emitted from the light emitting unit of the first detector at the light receiving unit of the first or second detector;
The light emitting part of the first detector is disposed at a position facing the light receiving part of the second detector, and the light emitting part of the second detector is a light receiving part of the first detector. A medium detection device, wherein the medium detection device is disposed at a position not facing the surface. A medium detection device according to claim 1,
A printer, wherein the medium is a medium for printing. The printer according to claim 2.
The medium detection device has a function of distinguishing and detecting, as the medium, a printing paper having a label attached to a strip-shaped mount, or a printing paper for a slip, and a printing paper having a preprint,
A printer having a function of detecting the absence of the medium. The printer according to claim 2 or 3,
A printer characterized in that when the medium is detected by the medium detection device, light is emitted from a light emitting unit of the first detector and is not emitted from a light emitting unit of the second detector.

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