JPH08151167A - Sheet detecting device - Google Patents

Abstract

PURPOSE: To prevent the detection error of an optical sensor while keeping a function capable of adjusting the arranging position of the optical sensor according to the width of a sheet to be installed. CONSTITUTION: A substantially U-shaped sensor holding body 14 having a pair of lengthy parts 16 arranged in parallel to each other and a connecting part 17 for mutually connecting one-side ends of the lengthy parts 16, which are molded thereon, is supported by a support part 15 in such a manner as to be capable of sliding. An optical sensor is held by the free ends of the lengthy parts 16 so that the optical axis of the optical sensor crosses a sheet route 7 situated between the lengthy parts 16. A regulating member 21a is stationarily arranged on the moving track of the free ends of the lengthy parts 16 for holding the optical sensor to regulate the mutually separating directional movements of the free ends of the lengthy parts 16. Thus, the oscillation of the lengthy parts 16 by the waving of a sheet 3 is arrested to prevent the detection error of the optical sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper detection device,
In particular, the present invention relates to a sheet detection device suitable for detecting a gap between labels on a label sheet and a mark attached to a long tag sheet.

[0002]

2. Description of the Related Art A paper detecting device is generally provided in a printing apparatus which guides a paper to a predetermined conveying path and performs predetermined printing on the paper in the guiding process.
For example, in a label printer that prints on a label affixed to a backing paper or a long tag paper, in order to align the printing position with respect to the label or the tag, the gap between the label and the label or the tag paper is attached at a predetermined position. It is necessary to detect the marked marks. A conventional example of such a label printer is shown in FIG.
And FIG. 3 will be described.

The overall schematic structure is shown in FIG. First, a case-shaped main body case 1 is provided, and in this main body case 1, a long label paper 3 wound in a roll shape and held by a holding shaft 2 is printed. A paper path 7 is formed to guide the paper to a predetermined path through the paper path 5 and the winding shaft 6. The printing unit 4 includes a platen 8, a thermal head 9 that contacts the platen 8 via the paper path 7, and a ribbon supply unit 11 that supplies an ink ribbon 10 between the platen 8 and the thermal head 9. And consists of. The label peeling unit 5 has a structure in which the label paper 3 is bent at an acute angle to peel the label 3b from the mount 3a. Therefore, only the mount 3a is wound around the winding shaft 6.

Next, in the paper path 7, the holding shaft 2
Between the sheet and the printing section 4, a meandering regulation section 12 that regulates the positional deviation of both ends of the label sheet 3 and a sheet detection device 13 are arranged. The meandering restricting portion 12 is composed of a pair of flat plate-like members, and the interval between the flat plate-like members is variably formed so as to accommodate label papers 3 of various widths. Further, as shown in FIG. 3, the sheet detection device 13 includes a sensor holder 14 that is formed in a substantially U shape and holds an optical sensor (not shown), and a support portion 15 that slidably supports the sensor holder 14. It is formed by and.
That is, the sensor holder 14 is formed by integrally molding a pair of long portions 16 arranged in parallel and a connecting portion 17 that connects one ends of the long portions 16. A wide holding portion 18 is formed on the free end side of the one long portion 16, and the optical sensor is embedded in the holding portion 18. The optical sensor is arranged so that its optical axis crosses the paper path 7. Further, a screw hole 19 having an axial direction in the sliding direction of the sensor holder 14 is formed on the free end side of the other long portion 16, and a support screw rotatably held in the main body case 1. By screwing 20 into the screw hole 19, the support portion 15 that supports the sensor holding body 14 is configured.

In such a structure, the backing paper 3a of the label paper 3 held by the holding shaft 2 is wound up by the winding shaft 6, whereby the label paper 3 is conveyed along the paper path 7. In the process of conveying the label paper 3, the printing unit 4 performs predetermined printing on the label 3a. At this time, the label 3 b is detected by the optical sensor held by the sensor holder 14.
The gap between the label and the label 3b, that is, the portion of the backing sheet 3a is detected, and the detection result is used for the print position alignment in the print unit 4.

In actual use, it is necessary to adjust the width of the meandering restricting portion 12 and the position of the sensor holding body 14 in accordance with the width of the label paper 3 mounted on the holding shaft 2. The position of the sensor holding body 14 is determined by rotating the support screw 20. Here, the label printer shown in FIGS. 2 and 3 can be used as a tag printer by mounting tag paper (not shown) on the holding shaft 2. In this case, the tag paper is provided with a mark for printing position alignment on its back surface, and this mark is detected by the optical sensor held by the sensor holder 14. For this reason, the configuration in which the sensor holding body 14 is slidably supported by the support portion 15 is an essential configuration when printing is performed on tag paper.

[0007]

The label paper 3 and the tag paper conveyed through the paper path 7 are slightly wavy as they progress. In particular, in the case of the label printer illustrated in FIGS. 2 and 3, the paper path 7 is farther than the paper detection device 13.
If the transport roller pair R located on the upstream side of the label sheet 3 has a structure for imparting a transport force to the label sheet 3 or the like, the label sheet 3 or the like is wavy due to the difference in the transport amount between the roller pair R and the platen 8. Occurs. Further, when a thermal paper is used for the label 3b or the like, the label 3b or the like tends to stick to the heating element (not shown) of the thermal head 9 at the printing position, and the waviness amplitude increases. When such waviness of the label paper 3 or the tag occurs at the portion of the optical sensor held by the sensor holding body 14, the free end of the long portion 16 of the sensor holding body 14 shakes up and down, and the optical sensor and the label paper. The distance between the third and the like will change. As a result, there is a problem that the output of the optical sensor becomes unstable and a detection error may occur. Further, when the label paper 3 is corrugated, there is a problem that the label 3b may be caught by the long portion 16 in the vicinity of the connecting portion 17 of the sensor holding body 14 and cause a paper jam.

[0008]

According to the first aspect of the present invention,
A substantially U-shaped sensor holding body in which a pair of long portions arranged in parallel and a connecting portion that connects one end of these long portions are molded, and a pair of long portions of the sensor holding body is a sheet of paper. On the straight line that connects the free ends of the long parts with the support parts that are positioned so as to sandwich the path and that slidably supports the long parts in the longitudinal direction. And an optical sensor having an optical axis. Also, fixedly arranged on the movement path of the free end of the long portion holding the optical sensor,
The elongated member has a restricting member that restricts the movement in the direction in which the free ends are separated from each other.

According to the second aspect of the present invention, the surface of the regulating member facing the paper path and the surface of the elongated portion whose movement is restricted by the restricting member facing the paper path are arranged in the same plane.

[0010]

Even if the paper guided in the paper path is corrugated, the regulation member prevents the long portion of the sensor holder from swinging, thereby preventing a detection error of the optical sensor held by the sensor holder. It Moreover, since the regulating member is arranged on the movement locus of the long portion holding the optical sensor,
Surely prevent the long portion from shaking regardless of the position of the sensor holder. Further, in the invention according to claim 2, since the surfaces of the regulating member and the elongated portion facing the paper path are formed in the same plane, it is difficult for the label of the label paper to be caught on the sensor holding body, and the per-per-jam is prevented. Less likely to occur.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. The same parts as those described with reference to FIGS. 2 and 3 are designated by the same reference numerals, and the description thereof will be omitted. Paper detection device 13
Is provided with a regulation member 21. This regulation member 2
1 is on the movement locus of the elongated portion 16 holding the optical sensor in the sensor holder 14, and along the swinging direction of the elongated portion 16, that is, the direction orthogonal to the longitudinal direction of the elongated portion 16. It is arranged. Further, the surface 21a of the regulation member 21 facing the paper path 7 and the surface 16a of the elongated portion 16 facing the paper path 7 whose swing is restricted by the restriction member 21 are in the same plane. The edges of the regulating member 21 and the elongated portion 16 that are formed and are continuous with the surfaces 16a and 21a are rounded.

In such a structure, even if the label sheet 3 is wavy, the movement of the long portions 16 in the direction in which the free ends thereof are separated from each other is regulated by the regulating member 21, so that the long portions 16 are oscillated. Be blocked. As a result, the distance between the optical sensor and the label sheet 3 does not fluctuate significantly, the output of the optical sensor is stable, and a detection error is prevented. Moreover, since the regulating member 21 is arranged on the movement locus of the long portion 16 that holds the optical sensor, it does not interfere with the sliding operation of the sensor holding body 14, and the sensor holding body 14 slides and is long. Even if the length portion 16 moves, the long portion 16 is reliably prevented from swinging. Further, the regulation member 2 facing the paper path 7
The first surface 21a and the surface 16a of the long portion 16 are located in the same plane, and the edges of the restriction member 21 and the long portion 16 which are continuous with the surfaces 16a, 21a are rounded.
For this reason, even if the label paper 3 is wavy, the areas of the surfaces 16a and 21a in contact with the label paper 3 are widened, and the rounded edges of the restriction member 21 allow the contact of the label 3b against the restriction member 21 smoothly. become. As a result, the label 3b is prevented from peeling off from the mount 3a due to being caught by the sensor holding body 14, and paper jam is less likely to occur.

[0013]

According to the first aspect of the present invention, the optical sensor is fixedly arranged on the moving locus of the free end of the long portion holding the optical sensor,
Since there is a restricting member that restricts the movement of the free ends of the long parts away from each other, even if the paper guided in the paper path is corrugated, the restricting member prevents the long part of the sensor holder from shaking. Therefore, the detection error of the optical sensor held by the sensor holder can be prevented. Further, since the regulating member is arranged on the movement locus of the long portion that holds the optical sensor, it is possible to reliably prevent the long portion from swinging regardless of the position of the sensor holder.

According to the second aspect of the present invention, since the surfaces of the regulating member and the elongated portion facing the sheet path are formed in the same plane, it is possible to prevent the label of the label sheet from being caught by the sensor holder. Therefore, it is possible to prevent the occurrence of a par jam.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional side view showing an example of a label printer using a sheet detection device as a conventional example.

FIG. 3 is a perspective view of a sheet detection device.

[Explanation of symbols]

 7 Paper Path 14 Sensor Holder 15 Supporting Part 16 Long Part 17 Connecting Part 21 Restricting Member

Claims (2)

[Claims] 1. A substantially U-shaped sensor holding body in which a pair of long portions arranged in parallel and a connecting portion connecting one end of these long portions are molded, and a pair of the sensor holding bodies. A supporting portion which is positioned at a position where the long portion sandwiches the paper path and slidably supports in the longitudinal direction of the long portion; and a long portion which is provided on the free end side of the long portion. An optical sensor having an optical axis on a straight line connecting the free ends of the long end is fixedly arranged on the moving path of the free end of the long part holding the optical sensor, and the free ends of the long part are A sheet detecting apparatus comprising: a regulating member that regulates a movement in a separating direction. 2. The surface of the regulation member facing the paper path and the surface of the long portion of which the movement is restricted by the restriction member facing the paper path are arranged in the same plane. 1. The paper detection device according to 1.