JP2008093872A - Display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent printing blur from occurring at the joint portion of thermal paper. <P>SOLUTION: Thermal paper 12 is superimposed at the opposite ends and bonded to form an endless loop. A thermal head 50A is fixed onto a subbase plate 52A. The subbase plate 52A is urged in the direction receding from a base plate 58A by a coil spring 56A, i.e. urged resiliently in the direction of the thermal paper 12. The base plate 58A is fixed to a housing (not shown). The thermal head 50A is pressed against the thermal paper 12 by the coil spring 56A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device that displays characters or images using a rewritable thermosensitive recording medium.

  The rewritable thermal paper, so-called rewritable paper, is colored by heating to a coloring temperature (for example, 180 degrees), and then cooled to fix the colored state, and the erasing temperature (for example, for example, from the coloring temperature) It is a paper material that can eliminate the colored state by heating and cooling to a low (120 to 160 degrees).

By using this type of rewritable thermal paper, it is possible to realize a display device that is suitable for use as a bulletin board or a guide plate and whose display contents can be changed (for example, see Patent Document 1). The end of the rewritable thermal paper is connected to form an endless loop, and the rewritable thermal paper in the loop can be conveyed between two feed rollers. Then, the rewritable thermal paper is heated by the thermal head to form a visible image such as a character or an image on the rewritable thermal paper. The previously recorded visible image can be erased by heating to the erasing temperature with the erasing heating head.
JP 2003-011404 A

  In order to maintain the print quality, the thermal head needs to be in close contact with the rewritable thermal paper. Therefore, the position of the thermal head and the rewritable thermal paper is usually adjusted so that the thermal head is in close contact with the rewritable thermal paper. Further, a rubber material having some elasticity may be used as a material of the platen roller disposed on the back surface of the thermal paper.

  In a display device used as a bulletin board or the like, both ends of the thermal paper are connected so as to partially overlap to form an endless loop, so that the thickness of the overlapping portion of the joint is approximately twice the thickness of the other portion. become. The rewritable paper is thicker than ordinary paper because the coloring layer and the protective layer are stacked on the base layer. There was a problem that the thermal head bounced before and after the joint, resulting in faint printing.

  In order to avoid this, the printing timing may be controlled so as to avoid the overlapping portion. However, in that case, it is necessary to set the thermal paper at a predetermined position of the paper feed mechanism, and considering the deviation due to the progress of use, the position of the overlapping portion is detected at an appropriate timing during use, and the print start position is adjusted. There must be.

  An object of the present invention is to provide a display device that can eliminate such inconvenience and obtain good print quality even in an overlapping portion.

  The display device according to the present invention is a rewritable thermal paper having an endless loop formed by overlapping both ends, and is rewritable by heating to a coloring temperature and erasing by heating to a decoloring temperature. Rewritable thermal paper, a paper feed mechanism that cyclically conveys the rewritable thermal paper, a thermal head that heats the thermal paper, and the thermal head and the rewritable portion at the joint of the rewritable thermal paper. The thermal head and the rewritable thermal paper are elastically biased so as to hold the possible thermal paper in close contact with each other.

  According to the present invention, the thermal head can be brought into close contact with the overlapping portion of the joint of the rewritable thermal paper. As a result, even if the rewritable thermal paper overlaps, the blurring is reduced or eliminated, and printing can be performed without worrying about the overlapping position.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an external perspective view of a mechanism unit according to one embodiment of the present invention, and FIG. 2 is a schematic block diagram of the present embodiment. In FIG. 2, members arranged around the thermal paper 12 are illustrated in a developed state of the thermal paper 12.

  The display device 10 according to the present embodiment is an information display used in general information on hotels and inns, bulletin corners of universities and vocational schools, or offices and showrooms of public offices, hospitals, and general companies. The display device 10 receives print data from a PC (Personal Computer) 40.

  The display device 10 uses the rewritable thermal paper 12 in an endless loop shape by partially overlapping and adhering both ends as a display medium for a visible image. Inside the rewritable thermal paper 12, the drive roller 14 and the driven roller 16 are arranged at a predetermined distance in the vertical direction, and the rewritable thermal paper 12 is held tightly. A motor 18 rotates the drive roller 14. As a result, the thermal paper 12 is conveyed in the direction indicated by the arrow in FIG.

  An opening 20 serving as a display window is provided in a housing that accommodates the paper feeding mechanism illustrated in FIG. Through the opening 20, a passer-by can read the printed content on the surface of the thermal paper 12.

  The thermal head unit 22A is disposed on the back side of the driving roller 14, and the thermal head unit 22B is disposed on the lower side of the driving roller 14. In FIG. 1, the thermal head unit 22B is illustrated apart from the driving roller 14 so that the shape of the thermal head unit 22B can be easily understood, but actually, the thermal head unit 22B is similar to the thermal head unit 22A. Is located near. The thermal head unit 22A is in charge of one side when the thermal paper 12 is divided into two in the width direction, and the thermal head unit 22B is in charge of the remaining side. Details of the configuration and arrangement of the units 22A and 22B will be described later.

  An erasing thermal head 26 is disposed upstream of the thermal head unit 22A. Further, a cooler 28 for cooling the thermal paper 12 by water cooling or air cooling is disposed on the downstream side of the thermal head unit 22B.

  The control box 30 accommodates a controller 32 that controls the whole, a memory 32 that stores print data as bitmap image data, and an interface 34 that is connected to the PC 40. Specifically, the controller 32 controls the paper feed of the thermal paper 12 by the drive motor 18, supplies a printing current to the thermal head units 22A and 22B, supplies an erasing current to the erasing thermal head 26, and The cooler 28 is operated in response to heating of the thermal paper 12 by the thermal head units 22A and 22B.

  The interface 34 is a modem device for fax reception, a communication port such as RS232C, a wired LAN (Local Area Network), a USB (Universal serial Bus), a wireless LAN such as IEEE (Institute of Electrical and Electronic Engineers) 802.1x, or A short-range wireless system such as Bluetooth.

  3 and 4 show cross-sectional views taken along line AA in FIG. 3 shows a state in which the thermal head 50A of the unit 22A is in close contact with the thermal paper 12, and FIG. 4 shows a state in which the thermal head 50A of the unit 22A is separated from the thermal paper 12. Normally, it is in the state shown in FIG. 3, and when the thermal paper 12 is replaced, it is temporarily in the state shown in FIG.

  A thermal head 50A is fixed on the sub-base plate 52A. A plurality of pins 54A are planted on the back surface of the sub-base plate 52A. Each pin 54A passes through the hole 60A of the coil spring 56A and the base plate 58A, and a bolt (or E ring or the like) 62A is fixed to the tip thereof. By fixing the bolt 62A to the tip of each pin 54A, the sub base plate 52A is prevented from being detached from the base plate 58A. The base plate 58A is fixed to a housing (not shown). The coil spring 56A is adjusted so as to bias the sub-base plate 52A in a direction to separate it from the base plate 58A. Therefore, in the state of being left, as shown in FIG. 3, the thermal head 50A is pressed against the thermal paper 12 by the coil spring 56A.

  The configuration of the thermal head unit 22B is exactly the same as the configuration of the thermal head unit 22A, and the thermal head 50B of the thermal head unit 22B is pressed against the thermal paper 12 by the coil spring 56B of the thermal head unit 22B.

  For example, the lateral width of the thermal paper 12 is slightly larger than the A1 standard paper width of 593 mm. By setting the height of the aperture window 20 to about A1 standard paper height of about 841 mm, the display area becomes almost A1 size. In this embodiment, the horizontal width of the thermal paper 12 is divided and handled by the two thermal head units 22A and 22B. Therefore, the thermal heads 50A and 50B may be any as long as they can support the horizontal width of the A3 standard.

  The thermal paper 12 of this embodiment develops a black color when heated to about 180 degrees Celsius, and the colored state is fixed by subsequent cooling. Further, when heated to a lower temperature of about 120 to 160 degrees, the colored state disappears and becomes decolored, and the decolored state is fixed by subsequent cooling. These coloring and decoloring temperatures vary depending on the thermal paper used.

  The basic operation of this embodiment will be described. Display data indicating the contents to be displayed on the controller 24 is transferred from the PC 40 via the interface 36. The controller 32 develops the display data into bitmap image data and stores it in the memory 34. In operation, the PC 40 regards the display device 10 of this embodiment as a printer and transmits display data to the display device 10.

  The controller 32 applies an erasing current that can heat the erasing thermal head 26 to an erasing temperature at which the display content of the thermal paper 12 can be erased. Then, the driving roller 14 is appropriately rotated by the motor 18 to convey the thermal paper 12. In response to the conveyance of the thermal paper 12, the controller 24 reads out bitmap image data of contents to be printed from the memory 34 and applies them to the thermal heads 50A and 50B of the thermal head units 22A and 22B. Of course, since the thermal head units 22A and 22B are shifted in the feeding direction of the thermal paper 12, the controller 24 reads out image data at a position corresponding to the shift amount from the memory 34 and applies it to the thermal heads 50A and 50B. To do.

  The thermal heads 50 </ b> A and 50 </ b> B partially overlap in the width direction of the thermal paper 12. The controller 24 applies print data to the thermal heads 50A and 50B so that the print portions in charge of the heads 50A and 50B do not overlap. This adjustment or setting may be performed before service.

  The action of bounce prevention by the coil springs 56A and 56B of the thermal head units 22A and 22B will be described. 5, 6, and 7 are enlarged side views of the joint portion of the thermal paper 12. FIG. 5 shows a state immediately before the thermal head 50A reaches the joint, FIG. 6 shows a state where the thermal head 50A gets on the joint, and FIG. 7 shows a state immediately after the thermal head 50A passes the joint. Show.

  In the joint portion, basically, the thickness of the thermal paper 12 is almost twice that of the other portions. In the present embodiment, the thermal head 50A is always pressed against the thermal paper 12 by the coil spring 56A, so that it extends from immediately before the joint (FIG. 5) to above the joint (FIG. 6) and after the joint (FIG. 7). Until then, the thermal head 50 </ b> A is kept in close contact with the thermal paper 12. Therefore, it is possible to print on the thermal paper 12 without any fading or noticeable printing fading regardless of the level difference due to the joint. In other words, printing can be performed without worrying about the joint position of the thermal paper 12.

  Because of this action, the coil springs 56A and 56B of the present embodiment have a restored length or a movable length that exceeds the thickness of the thermal paper 12.

  In the above embodiment, the thermal head of the roller and the thermal head sandwiching the thermal paper 12 is elastically pressed against the thermal paper 12, but conversely, the roller may be pressed against the thermal paper 12. FIG. 8 is a side view of an embodiment in which the thermal head is fixed and the platen roller is elastically biased toward the thermal head. The same components as those in the first embodiment are denoted by the same reference numerals. Elements different from the first embodiment will be described.

  The thermal head 70 is fixed to the base plate 72. The base plate 72 is fixed to a casing (not shown) through a movable mechanism that retracts the thermal head 70 from the travel area of the thermal paper 12 when the thermal paper 12 is replaced. ing.

  A platen roller 74 is disposed at a position facing the thermal head 70 via the thermal paper 12. The rotation shaft 76 of the platen roller 74 is elastically biased toward the thermal paper 12 by a coil spring 78 at both ends thereof. The other end of each coil spring 78 is fixed to a base plate 80 fixed to the housing.

  Since the platen roller 74 is always elastically biased toward the thermal head 70 by the action of the coil spring 78, the thermal paper 12 can be applied to the thermal head 60 at a portion other than the joint or at the joint. It will always be pressed. As a result, the thermal head 70 adheres to the thermal paper 12 at any stage before, during and after the joint of the thermal paper 12. Similar to the coil springs 56A and 56B of the first embodiment, the coil spring 78 has a restored length or a movable length that exceeds the thickness of the thermal paper 12.

  Although the invention has been described with reference to specific illustrative embodiments, various modifications and alterations may be made to the above-described embodiments without departing from the scope of the invention as defined in the claims. This is obvious to an engineer in the field to which the present invention belongs, and such changes and modifications are also included in the technical scope of the present invention.

It is a perspective view of the main mechanism part of Example 1 of the present invention. 2 is a functional block diagram of Embodiment 1. FIG. FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 and shows a state in which a thermal head 50A is in close contact with the thermal paper 12. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 and shows a state in which a thermal head 50A is separated from the thermal paper 12 against a coil spring 56A. 4 is a side view of a state in which a thermal head 50A is located immediately before a joint of thermal paper 12. FIG. 4 is a side view of a state in which a thermal head 50A is on a joint of thermal paper 12. FIG. FIG. 6 is a side view after the thermal head 50A has passed through the joint of the thermal paper 12. It is a side view of Example 2 of the present invention.

Explanation of symbols

10: display device 12: rewritable thermal paper 14: driving roller 16: driven roller 18: motor 20: opening of housing (display window)
22A, 22B: Thermal head unit 26: Thermal head 28 for erasing 28: Cooler 30: Control box 32: Controller 32: Memory 34: Interface 40: Computer (PC)
50A, 50B: Thermal heads 52A, 52B: Sub-base plates 54A, 54B: Pins 56A, 56B: Coil springs 58A, 58B: Base plate 60A: Hole 62A: Bolt 70: Thermal head 72: Base plate 74: Platen roller 76: Rotation Shaft 78: Coil spring 80: Base plate

Claims (3)

A rewritable thermal paper that is endless looped by overlapping both ends, and is rewritable thermal paper (12) that develops color by heating to a coloring temperature and decolors by heating to a decoloring temperature;
A paper feed mechanism (14, 16, 18) for cyclically conveying the rewritable thermal paper (12);
A thermal head (50A, 70) for heating the thermal paper (12);
The thermal head and the rewritable sheet are held so that the thermal head (50A, 70) and the rewritable thermal sheet (12) are held in close contact with each other at the joint portion of the rewritable thermal sheet (12). Elastic member (56A, 78) that elastically biases one of the possible thermal papers (12)
A display device comprising:   The display device according to claim 1, wherein the elastic member is means (56A) for elastically pressing the thermal head (50A) against the rewritable thermal paper (12).   The display device according to claim 1, wherein the elastic member has a restoration length exceeding a thickness of the rewritable thermal paper.

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