JP2009233916A - Thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal printer improved in the accuracy of positional detection of a label and tag. <P>SOLUTION: In the thermal printer 100, an organic electroluminescent 110 which is a planar light source arranged on the undersurface of a label pressing part 106 emits a light of uniform intensity downwards from the planar luminescence surface, and a light receiving part 112 arranged in the position opposite to the organic electroluminescent 110 across the conveyance path receives the light which has permeated both the label 320 and a pasteboard 310 and the light having permeated only the pasteboard 310. A positional detection function 104 in a control part 102 detects the end of the label 320 from the change of the light intensity in the light receiving part 112. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermal printer that detects the position of a conveyed sheet and performs printing in order to perform printing at an appropriate position on a sheet such as a label or a tag.

  2. Description of the Related Art Conventionally, thermal printers that perform printing on a plurality of labels temporarily attached to a mount at regular intervals and paper such as strips having tags at regular intervals are known. The thermal printer needs to detect the position of the conveyed label or tag in order to print at an appropriate position of the label or tag. In such label and tag position detection, a so-called transmission sensor may be used. In this transmission sensor, a light emitting element and a light receiving element are arranged so as to face each other across a conveyance path for conveying a label or a tag.

  In this transmission sensor, the light emitting element irradiates light toward a label or tag. On the other hand, when the label is temporarily attached to the mount, the light receiving element receives the light emitted from the light emitting element and transmitted through both the label and the mount and the light transmitted through only the mount. At this time, the light that passes through the label and the mount and reaches the light receiving element and the light that passes through only the mount and reaches the light receiving element have different intensities. It becomes possible to detect. Further, in the case of a tag, the light receiving element receives light emitted from the light emitting element and transmitted through the tag and light that reaches directly through a hole or the like formed in the tag. At this time, the light passing through the tag and reaching the light receiving element is different in intensity from the light passing through the hole formed in the tag and directly reaching the light receiving element. The position of the formed hole or the like can be detected.

  When the above-described transmission sensor is used, the position of the paper width (width in the direction perpendicular to the conveying direction), the hole, or the like differs depending on the label or tag to be detected. is there. However, if the light-emitting element and the light-receiving element do not face each other after movement and the optical axes do not coincide with each other, the intensity of light reaching the light-receiving element decreases, and whether or not the intensity exceeds a predetermined threshold value. When detecting the position of the end of the label, the hole of the tag, or the like, accurate detection becomes difficult. For this reason, by using a U-shaped holding part and arranging the light emitting element and the light receiving element at both ends of the U-shaped holding part and moving the entire holding part, the light emitting element and the light receiving element are moved. There are techniques for maintaining the facing of the element. However, in this method, the operation of adjusting the facing of the light emitting element and the light receiving element is frequently performed in the production process of the thermal printer, and the adjustment may take a long time. Therefore, a method has been proposed in which a plurality of light emitting elements are arranged in a line in a direction perpendicular to the transport direction so that only the light receiving elements are moved, and after moving, the light emitting elements are opposed to each other before the movement. (For example, refer to Patent Document 1).

JP-A-6-183114

  However, in the method of arranging a plurality of light emitting elements in a row and moving only the light receiving elements, each of the light emitting elements is a point light source, so that the light intensity at a position equidistant from the light emitting element is constant. It will be wavy. For this reason, for example, when the light emitting element is positioned in front of the light receiving element and between the light emitting elements adjacent to the front of the light receiving element, the intensity of light reaching the light receiving element is different, and the accurate position This hinders detection.

The present invention has been made to solve the above-described conventional problems, and provides a thermal printer with improved accuracy of label and tag position detection.

  According to the present invention, there is provided a thermal printer for detecting a position of a conveyed sheet and performing printing in order to perform printing at an appropriate position of the sheet, the thermal printer being disposed in the sheet conveyance path, and A planar light source that emits light of uniform intensity toward the paper, and a light receiving unit that is disposed at a position facing the planar light source across the conveyance path, and that receives the light emitted from the planar light source; And detecting means for detecting the position of the sheet based on the intensity of light received by the light receiving unit.

  According to this configuration, the planar light source has a planar light emitting surface, and irradiates light of uniform intensity from the planar light emitting surface toward the paper. Therefore, the light receiving unit is equidistant from the planar light source. Even if it moves in a certain position, the intensity of light directly reaching the light receiving part from the planar light source is constant. Therefore, in the light receiving unit, it is possible to accurately capture the difference in intensity between the light emitted from the planar light source and transmitted through the paper, and the accuracy of detecting the position of the paper can be improved.

  Further, the thermal printer according to the present invention has a pressing portion disposed in the paper conveyance path and abutting against the paper, and the planar light source is disposed at a position facing the conveyance path in the pressing portion. The

  According to this configuration, by using the pressing portion, it is possible to make the distance between the light emitting surface and the paper constant, prevent paper flapping, and stably detect the position of the paper. Further, by integrating the planar light source and the pressing portion, it is only necessary to lift the pressing portion in the operation of opening the conveyance path, and operations such as cleaning and maintenance are facilitated.

  In the thermal printer according to the present invention, the pressing portion includes a roller that contacts the paper.

  In the thermal printer according to the present invention, the planar light source is electroluminescence.

By using electroluminescence as a planar light source, it becomes possible to easily irradiate light having a uniform intensity from a planar light emitting surface.

According to the present invention, the light receiving unit can accurately capture the difference in intensity of light emitted from a planar light source and transmitted through a sheet such as a label or a tag, and improve the position detection accuracy of the sheet.

  Hereinafter, a thermal printer according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a thermal printer according to an embodiment of the present invention. The thermal printer 100 shown in FIG. 1 detects the position of a label 320 temporarily attached to a strip-shaped mount (release paper) 310 in a label sheet 300 conveyed on a conveyance path.

  The thermal printer 100 includes a control unit 102, a label pressing unit 106, an organic electroluminescence 110 as a planar light source, and a light receiving unit 112. Among these, the control unit 102 has a position detection function 104 for the label 320.

  A label paper 300 wound in a roll shape is mounted on the conveyance path, and the label paper 300 drawn out from a supply reel (not shown) is conveyed. The label pressing part 106 and the organic electroluminescence 110 are arranged in the upper part of this conveyance path. On the other hand, the light receiving unit 112 is disposed in the lower part of the conveyance path. Hereinafter, details of the arrangement of the label pressing unit 106, the organic electroluminescence 110, and the light receiving unit 112 will be described.

  2 is a perspective view showing the arrangement of the label holding unit 106, the organic electroluminescence 110, and the light receiving unit 112. FIG. 3 is a front view showing the arrangement of the label holding unit 106, the organic electroluminescence 110, and the light receiving unit 112. FIG.

  As shown in FIGS. 2 and 3, the label pressing portion 106 and the organic electroluminescence 110 are integrated. The lower surface of the label pressing unit 106 is in contact with the upper surface of the label 320 in the label paper 300 to be conveyed, thereby suppressing the flapping of the label paper 300. A concave portion is formed on the lower surface of the label pressing portion 106. Furthermore, the organic electroluminescence 110 extending in the direction perpendicular to the conveyance direction of the label paper 300 is disposed in the concave portion. The organic electroluminescence 110 has a light emitting surface 111 having a flat bottom surface, and emits light having a uniform intensity downward from the light emitting surface 111 by the power supplied from the control unit 102.

  The light receiving unit 112 is disposed at a position facing the light emitting surface 111 of the organic electroluminescence 110 across the conveyance path of the label paper 300. The light receiving unit 112 has a light receiving surface 113 on the upper surface. The light receiving unit 112 is attached to a paper guide (not shown), and is provided so as to be movable in the paper width direction of the label paper 300, that is, in the direction perpendicular to the transport direction when the label paper 300 is set. In any position within this moving range, the light emitting surface 111 of the organic electroluminescence 110 is opposed.

  The light emitted from the light emitting surface 111 of the organic electroluminescence 110 is incident on the upper surface of the label 320 when a label 320 is present directly below the light emitting surface 111, and a part of the light is emitted from the label 320 and the label 320. Through the bottom mount 310 and downward. On the other hand, the light emitted from the light emitting surface 111 of the organic electroluminescence 110 is incident on the upper surface of the mount 310 and part of the light is transmitted when only the mount 310 exists immediately below the light emitting surface 111. Head down.

  Both the light transmitted through both the label 320 and the mount 310 and the light transmitted through only the mount 310 reach the light receiving surface 113 of the light receiving unit 112 and are received. The intensity of light received by the light receiving unit 112 is small when the light emitted from the light emitting surface 111 of the organic electroluminescence 110 passes through both the label 320 and the mount 310, and when the light passes through only the mount 310. Will grow. The light receiving unit 112 detects the intensity of the received light at a predetermined cycle, and outputs the detected light intensity to the control unit 102.

  When the intensity of light from the light receiving unit 112 is input, the position detection function 104 in the control unit 102 determines whether or not the intensity is equal to or greater than a predetermined threshold. As described above, the intensity of light received by the light receiving unit 112 is small when both the label 320 and the mount 310 are transmitted, and is large when only the mount 310 is transmitted. Correspondingly, the threshold value is the light reception in the case of transmitting both the label 320 and the mount 310 so that it can be discriminated whether the label 320 and the mount 310 are transmitted. It is set to a value between the light intensity at the unit 112 and the light intensity at the light receiving unit 112 when only the mount 310 is transmitted.

  Further, the position detection function 104 in the control unit 102 allows the front end in the conveyance direction of the label 320 to be directly above the light receiving unit 112 when the light intensity at the light receiving unit 112 that has been equal to or higher than the threshold changes to less than the threshold. It is determined that the part is located. On the other hand, the position detection function 104 in the control unit 102 allows the label 320 to follow the conveyance direction of the label 320 immediately above the light receiving unit 112 when the light intensity in the light receiving unit 112 that has been less than the threshold value changes to the threshold value or more. Judge that the end is located.

  When the positions of the front end portion and the rear end portion of the label 320 are detected in this way, the control unit 102 is based on the conveyance speed of the label paper 320 and the distance in the conveyance direction from the light receiving unit 112 to the thermal head. Then, it is determined whether or not the label 320 is further conveyed and reaches directly below a thermal head (not shown). When it is determined that the label 320 has reached directly below the thermal head, the control unit 102 instructs the thermal head to print on the label 320. In response to this instruction, the thermal head prints on the label 320.

  As described above, in the thermal printer 100 according to the present embodiment, the organic electroluminescence 110 that is a planar light source disposed on the lower surface of the label pressing unit 106 has light of uniform intensity from the planar light emitting surface 111 downward. , And the light receiving unit 112 disposed at a position facing the organic electroluminescence 110 across the conveyance path receives light transmitted through both the label 320 and the mount 310 and light transmitted only through the mount 310. The position detection function 104 in the control unit 102 detects the end portion of the label 320 based on the change in the light intensity in the light receiving unit 112.

  By using the organic electroluminescence 110 as a planar light source, it is possible to irradiate light having a uniform intensity from the planar light emitting surface 111 toward the label 320, and the light receiving unit 112 is emitted from the light emitting surface 111. Even if it moves in a position at a distance, the intensity of light that directly reaches the light receiving unit 112 from the organic electroluminescence 110 is constant. Therefore, in the light receiving unit 112, the intensity difference between the light transmitted through both the label 320 and the mount 310 and the light transmitted through only the mount 310 can be accurately captured, and the position detection accuracy of the label 320 can be improved.

  In addition, by using the lower surface of the label pressing unit 106 as a pressing member in contact with the label 320, the flapping of the label paper 300 is suppressed, the distance between the light emitting surface 111 and the label 320 is fixed, and the position of the label 320 is stably detected. Is possible.

  By the way, in the above-described embodiment, the light emitting surface 111 and the lower surface of the label pressing unit 106 are used as the pressing by contacting the label 320, but various other configurations are conceivable. For example, in the configuration shown in FIG. 4, the lower surface of the label pressing portion 106 is not in contact with the label 320 as compared to the configuration shown in FIG. 3. On the other hand, in the configuration shown in FIG. 4, a roller 114 that rotates as the label sheet 300 is transported is disposed in the lower portion of the label pressing unit 106, and a label is positioned at a position facing the roller 114 across the transport path. A roller 116 that rotates as the paper 300 is conveyed is disposed. The roller 114 abuts against the label 320 while rotating, and the roller 116 abuts against the mount 310 while rotating, thereby suppressing flapping of the label sheet 300.

  In the above-described embodiment, the position detection of the label 320 temporarily attached to the mount 310 has been described. However, the present invention can be similarly applied to the position detection of a band-like tag having holes at equal intervals. . In this case, the configuration shown in FIG. 4 can be applied in addition to the configuration shown in FIG.

  In the above-described embodiment, the organic electroluminescence 110 is used as a planar light source. However, if the planar light source emits uniform light from a planar light emitting surface such as inorganic electroluminescence, the present invention is similarly applied. The invention can be applied.

  As described above, the thermal printer according to the present invention can improve the accuracy of detecting the position of paper such as labels and tags, and is useful as a thermal printer.

It is a figure which shows the structure of a thermal printer. It is a perspective view which shows arrangement | positioning of a label holding | maintenance part, organic electroluminescence, and a light-receiving part. It is a 1st front view which shows arrangement | positioning of a label holding | maintenance part, organic electroluminescence, and a light-receiving part. It is a 2nd front view which shows arrangement | positioning of a label holding | maintenance part, organic electroluminescence, and a light-receiving part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Thermal printer 102 Control part 104 Position detection function 106 Label holding part 110 Organic electroluminescence 111 Light emission surface 112 Light reception part 113 Light reception surface 114,116 Roller 300 Label paper 310 Mount 320 Label

Claims (4)

A thermal printer that detects the position of a conveyed paper and performs printing in order to perform printing at an appropriate position on the paper,
A planar light source that is disposed in the paper transport path and that emits light of uniform intensity from a planar light emitting surface toward the paper;
A light receiving unit that is disposed at a position facing the planar light source across the conveyance path, and that receives light emitted from the planar light source;
A thermal printer having detection means for detecting the position of the paper based on the intensity of light received by the light receiving unit. A pressing portion disposed in the paper conveyance path and in contact with the paper;
The thermal printer according to claim 1, wherein the planar light source is disposed at a position facing the conveyance path in the pressing portion.   The thermal printer according to claim 2, wherein the pressing portion includes a roller that contacts the paper.   The thermal printer according to claim 1, wherein the planar light source is electroluminescence.

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