JPH0524367U - Thermal transfer recorder - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a small-sized and inexpensive thermal transfer recording device in which the image receiving paper is reliably conveyed and wrinkles are prevented from occurring on the ink sheet. An image receiving paper 36 and an ink sheet 30 are sandwiched between a thermal head 24 and a platen roller 20, and while the image receiving paper is being conveyed, the ink on the ink sheet is transferred to the image receiving paper by the thermal head to form an image. Form. In order to bring the image receiving paper into close contact with the platen roller via an ink sheet, the length is longer than the width of the ink sheet, and the inner side in the width direction of the side frame of the ink sheet cassette 31 accommodating the ink sheet. A rotation guide roller 43 shorter than the size is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thermal transfer recording apparatus in which an image receiving paper and an ink sheet are sandwiched between a thermal head and a platen roller, and the ink on the ink sheet is transferred to the image receiving paper to record an image on the image receiving paper.

[0002]

[Prior Art]

 In this type of thermal transfer recording apparatus, in order to reliably transfer the ink to the image receiving paper, it is necessary to accurately convey the image receiving paper to the platen roller.

As a conventional device for this purpose, a platen roller having a large diameter is used, and the front end of the image receiving paper is clamped by a clamp mechanism so that it is wound around the peripheral surface of the platen roller. It is known that a roller with a small diameter is used, and a pinch roller is arranged on the paper discharge side of this platen roller to enhance the adhesion between the peripheral surface of the platen roller and the image receiving paper. It is being done.

[0004]

[Problems to be solved by the device]

 However, in the former type of device, not only does the device itself increase in size as the diameter of the platen roller increases, but also a complicated clamping mechanism is required, which causes a problem of high cost. On the other hand, in the latter type of device, although there is no such drawback, the tip of the image receiving paper ejected from the platen roller tends to go straight along the support substrate of the thermal head, so this tip is pinched by the pinch roller. It may not be conveyed between the platen roller and the platen roller. That is, there is a problem in the reliability of conveyance of the image receiving paper.

In the latter device, the applicant has arranged a guide roller between the sheet discharge side of the platen roller and the pinch roller to ensure that the leading end of the discharged image receiving sheet serves as the pinch roller. I applied for a technology to guide it between the platen roller. However, in this prior application, the guide roller, which is in sliding contact with the back surface of the ink sheet, is set so that the entire length thereof is narrower than the width of the ink sheet. This is because if the length of the guide roller is simply increased, not only the size of the device will be increased, but also the guide roller and the side frames of the ink sheet cassette will interfere with each other, which may hinder the rotation of the guide roller. Because there is. However, as in this prior application, when a short guide roller is used, the guide roller does not make sliding contact over the entire width of the ink sheet, so that the tension on the take-up side of the ink sheet becomes uneven in the width direction. For this reason, the ink sheet is stretched at the central portion and wrinkles occur. As a result, what is called a transfer mark is generated in the formed image.

Therefore, an object of the present invention is to provide a thermal transfer recording apparatus which can make the apparatus small and inexpensive, can reliably convey the image receiving paper, and is free from wrinkles on the ink sheet. It is to be.

[0007]

[Means for Solving the Problems]

 According to the present invention, an image receiving paper and an ink sheet are sandwiched between a thermal head and a platen roller, and while the image receiving paper is being conveyed, the ink on the ink sheet is transferred to the image receiving paper by the thermal head to form an image, In a thermal transfer recording apparatus in which an image receiving paper on which an image is formed is sandwiched between a platen roller and a pinch roller and conveyed, the image receiving paper is rotatable in order to bring the image receiving paper into close contact with the platen roller via an ink sheet. A guide roller having a length longer than the width of the ink sheet and shorter than the inner dimension of the frame of the ink sheet cassette accommodating the ink sheet in the width direction is positioned at least at the time of transfer in the frame of the ink sheet cassette. Is characterized by.

[0008]

[Action]

 The fed image receiving paper is conveyed together with the ink sheet between the platen roller and the thermal head, and the thermal head transfers the image through the ink sheet. The image receiving paper on which the image has been transferred is ejected from between the platen roller and the thermal head, and is conveyed between the platen roller and the pinch roller while being pressed against the outer peripheral surface of the platen roller by the guide roller and ejected. It In this way, the image receiving paper discharged from between the platen roller and the thermal head is pressed against the outer peripheral surface of the platen roller by the guide roller and guided in the direction of the pinch roller. On the other hand, the ink sheet used for transfer is guided by the guide roller while receiving tension in the width direction, and is conveyed between the platen roller and the guide roller.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

A pair of frames fixed in a housing (not shown) of the thermal transfer recording apparatus includes a small-diameter platen roller 20 and a paper feed side pinch roller 21 shown in FIG. The paper discharge side pinch roller 22 is rotatably supported. The platen roller 20 has an outer peripheral surface made of a material having a large friction coefficient, for example, rubber, and is rotationally driven by a driving mechanism (not shown) in the clockwise direction in FIG. 1 during transfer. The pinch rollers 21 and 22 are urged from both sides of the platen roller 20 in the rotation axis direction of the platen roller 20 by pressing means (not shown). As a result, both pinch rollers 21 and 22 are pressed against the outer peripheral surface of the platen roller 20, and as the platen roller 20 rotates, the image receiving paper is moved between the sheet feeding side and the sheet discharging side between them. Guide along the outer surface. Below the platen roller 20, a thermal head 24 having a heating element line 24a (shown in FIGS. 2 and 3) is provided supported by a support substrate. The thermal head 24 is pivotally supported on the frame at one end by a head arm shaft 37, and is supported at the other end of a head support arm 32 rotatable about the head arm shaft 37 via a radiator 25. Has been done. As a result, the thermal head 24 is movable between a transfer position where it contacts the platen roller 20 and a loading position where it is separated from the platen roller 20 and an ink sheet cassette 31 described later can be loaded. Further, the thermal head 24 is biased toward the platen roller 20 at the transfer position thereof by a biasing means (not shown). These members are arranged so that the nip position between the thermal head 24 and the platen roller 20 is substantially in the center between the paper feed side pinch roller 21 and the paper discharge side pinch roller 22. There is. To the radiator 25, the base end portion of an L-shaped guide roller support arm 46 is fixed by an arm fixing member 47. A guide roller 43, which will be described later, is rotatably supported at the tip of the guide roller support arm 46. Thus, the guide roller 43 can be moved together with the thermal head 24 by the rotation of the head support arm 32. As a result, when the thermal head is moved to the transfer position, the guide roller 43 is positioned near the pinch roller 22 between the pinch roller 22 and the nip position between the thermal head 24 and the platen roller 20. The guide roller support arm 46 is set so that it can contact the outer peripheral surface of the platen roller 20.

An ink sheet cassette 31 is detachably supported on the frame by a support mechanism (not shown). The ink sheet cassette 31 is provided on one end side and has a winding reel chamber in which the winding reel 29 is rotatably housed and a delivery reel chamber in which the delivery reel 28 is rotatably housed in the other end side. Have. When the ink sheet cassette 31 is mounted on the frame, the take-up reel 29 is connected to a drive mechanism (not shown) so that the ink sheet 30 wound around the delivery reel 28 can be taken up. Further, when the platen roller 20 is at the loading position and the ink sheet cassette 31 is loaded, the ink sheet 30 stretched between the delivery reel 28 and the take-up reel 29 becomes the platen roller 20 and the thermal head 24. The ink sheet cassette 31 and the head support arm 32 are arranged so that they can be inserted between the platen roller 20 and the guide roller 43. As the ink sheet 30, a thermoplastic such as polyethylene terephthalate film may be used. This film is preferably extremely thin, mainly about 5 μm in thickness, so that the heat energy applied from the heating element of the thermal head 24 can be efficiently transmitted to the ink layer of the ink sheet 30 (described later). As such, thinner ones are desirable to increase the recording speed).

Above the platen roller 20, a paper feed side guide plate 33 and a paper discharge side guide plate 34 are arranged substantially parallel to each other. The paper feed side guide plate 33 guides the untransferred image receiving paper 36 conveyed from an image receiving paper supply unit (not shown) between the platen roller 20 and the pinch roller 21 between the outer surface of the ink sheet cassette 31. Further, the paper discharge side guide plate 34 guides the image receiving paper 36 after transfer, which is discharged from between the platen roller 20 and the pinch roller 22, to an image receiving paper discharging unit (not shown). The image receiving paper is carried by the platen roller and the image receiving paper conveying means (not shown). The transfer operation of the thermal transfer recording apparatus having the above configuration will be briefly described.

In the state shown in FIG. 1 in which the ink sheet cassette 31 is loaded in the housing and the thermal head 24 is brought to the transfer position, the image receiving paper 36 is the paper feed side guide plate 33 and the ink sheet cassette 31. The sheet is fed from the outer side of the sheet and is sandwiched between the platen roller 20 and the sheet feeding side pinch roller 21. Further, the image receiving paper 36 is conveyed between the platen roller 20 and the thermal head 24 by the sandwiching, and the image is transferred to the one surface of the image receiving paper 36 by the thermal head 24 through the ink sheet 30. The image receiving paper 36 on which the image has been transferred is discharged from the nip position between the platen roller 20 and the thermal head 24, and is pressed against the outer peripheral surface of the platen roller 20 by the guide roller 43 while being pinched by the platen roller 20 and the discharge side pinch. It is conveyed to a nip point with the roller 22 and further discharged through the guide plate 34. In this way, the image receiving paper 36 discharged from the nip position between the platen roller 20 and the thermal head 24 is pressed against the outer peripheral surface of the platen roller 20 by the guide roller 43, and the direction of the paper discharge side pinch roller 22 is increased. Without being guided, the sheet is reliably fed to the nip point between the platen roller 20 and the pinch roller 22. On the other hand, the ink sheet 30 used for the transfer is guided by the guide roller 43, passes between the platen roller 20 and the guide roller 43, and is wound up by the winding reel 29. As a result, the ink sheet 30 does not come into contact with the edge of the supporting substrate of the thermal head 24, so that the ink sheet 30 may be added excessively or the ink sheet 30 may be partially tensioned. There is no such thing. The ink sheet 30, the ink sheet cassette 31, and the guide roller 43 will be described in more detail with reference to FIGS. 2 and 3.

The guide roller 43 is composed of three hollow rollers 43a, 43b, 43c which are fixed to the tip of a guide roller support arm 46 and are rotatably supported by a horizontally extending guide roller shaft 50. Has been done. The guide roller shaft 50 penetrates through the central through holes of the hollow rollers 43a, 43b, 43c arranged in a line, and E-rings 51 are attached to both ends thereof so as not to fall off. The entire length of the guide roller 43 (the distance between the outer ends of the hollow rollers 43b and 43c located outside) is larger than the width of the ink sheet 30, and the distance between the inner surfaces of the side frames 31a and 31a of the ink sheet cassette 31. It is set shorter than (the inner dimension in the width direction of the frame). Further, in this embodiment, as the material for forming the guide roller 43, a polyamide resin having a small friction coefficient mixed with molybdenum disulfide for the purpose of further increasing lubricity is used. The material is not limited to this.

By using the guide roller 43 as described above, the guide roller 43 abuts over the entire width of the ink sheet 30 when the ink sheet 30 is being conveyed, so Applies not only the tension in the transport direction but also the tension in the width direction. Therefore, in order to increase the printing speed while keeping the printing density constant by increasing the thermal energy applied in the unit time or increasing the thermal efficiency, the ink sheet 30 should be used as much as possible, for example. Even if the thickness is reduced to 2 to 3 μm, wrinkles do not occur on the ink sheet 30 during transportation. As a result, it is possible to prevent the transfer marks due to the generation of wrinkles. Further, since the length of the guide roller 43 is set to be shorter than the inner dimension between the side frames 31a, 31a of the ink sheet cassette 31, the length of the guide roller 43 is set within the plane connecting the outer peripheral surfaces of the feed reel 28 and the take-up reel 29. Even if the thermal head 24 is pressed against the platen roller 20 at a deeper position, the guide roller 43 and the ink sheet cassette 31 do not collide with each other and interfere with each other.

In the above embodiment, the guide roller is composed of three hollow rollers, but it may be composed of a different number of rollers. For example, the guide roller may be composed of one roller. Although the guide roller is fixed to the thermal head, it may be movable by, for example, rotatably supporting the guide roller support arm on the thermal head (radiator). The pinch roller on the paper feed side is not always necessary.

[0017]

[Effect of the device]

 In the thermal transfer recording apparatus according to the present invention, a platen roller having a small diameter can be used, so that the apparatus can be made small and inexpensive. Further, the guide roller and the pinch roller enable reliable conveyance of the image receiving paper, and by making the guide roller a predetermined length, there is no risk of wrinkles on the ink sheet.

[Brief description of drawings]

FIG. 1 is a side view showing a thermal transfer recording apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of the thermal transfer recording apparatus shown in FIG.

3 is an enlarged plan view of a main part of the device shown in FIG.

[Explanation of symbols]

20 ... Platen roller, 21, 22 ... Pinch roller, 2
4 ... Thermal head, 30 ... Ink sheet, 31 ... Ink sheet cassette, 36 ... Image receiving paper, 43 ... Guide roller.

Claims (1)

[Scope of utility model registration request] 1. An image receiving sheet and an ink sheet are sandwiched between a thermal head and a platen roller, and while the image receiving sheet is being conveyed, the ink on the ink sheet is transferred to the image receiving sheet by the thermal head to form an image. In a thermal transfer recording device that conveys an image receiving paper on which an image is formed by sandwiching it between a platen roller and a pinch roller, in order to bring the image receiving paper into close contact with the platen roller via an ink sheet, it is rotatable, Positioning a guide roller having a length longer than the width of the ink sheet and shorter than an inner dimension of the frame of the ink sheet cassette accommodating the ink sheet in the width direction at least at the time of transfer in the frame of the ink sheet cassette. A thermal transfer recording device characterized by: