JPH0138103Y2 - - Google Patents

Description

[Detailed Description of the Invention] (A) Field of Industrial Application The present invention relates to a thermal transfer printer, and particularly to a sheet roll holding mechanism that rotatably and detachably holds a sheet roll from both ends thereof.

(b) Prior Art At present, thermal transfer printers exist as devices for printing high-quality records on plain paper. FIG. 2 shows this type of printer, and 20 is an ink sheet roll in which an ink sheet 20a is wound around a core 21;
2 is a thermal head, 23 is a platen facing the thermal head, and 24 is an ink sheet 2.
0a is a winding roll, 25 is a feed roller, and 26 is a recording paper. Desired recording is performed on the recording paper 26 by supplying the ink sheet 20a from the ink sheet roll 20 and bringing the recording paper 26 into contact with the thermal head 22 via the ink sheet 20a. And used ink sheet 20
A is wound up by a winding roll 24.

Therefore, this type of printer requires a mechanism for holding the ink sheet roll 20 in a rotatable and detachable manner.

FIG. 3 shows a conventional example as seen in, for example, Utility Model Application No. 58-67856. 30 is a frame portion, 31 is a left holding body, and 32 is a right holding body. This left and right holding body 3
1 and 32 rotatably hold both ends of the ink sheet roll 1. 33 is a first fixed shaft fixed to the frame part 30, 34 is a left reel plate attached to the tip of the fixed shaft, and in the center of the reel plate is a shaft with a diameter slightly smaller than the inner diameter of the core 2 of the ink sheet roll. A left engaging portion 35 is provided.

36 is a second fixed shaft fixed to the frame part 30; 37 is a holding part movably inserted into the second fixed shaft 36; Right reel plate 3 attached to the
9 and a right engaging portion 40 provided on the right reel plate 39. A spring 41 is wound around the second fixed shaft 36 between the frame portion 30 and the holding portion 37, and this spring presses the holding portion 37 in the direction of the ink sheet roll 1. In the insertion portion 38, a first hole 38a having approximately the same diameter as the second fixed shaft 36 is bored from the right side, and a second hole 38b having a larger diameter is provided following the first hole 38a. Further, 42 is an E-ring fixed to the tip of the second fixed shaft 36 to prevent the holding part 37 from coming off.

In such a structure, the spring 41 presses the holding portion 37 to the left, so that the ink sheet roll 1 has its core 2 aligned with the left and right reel plates 34,
It is held between left and right engaging portions 35 and 40 provided at 39. Then, when the ink sheet is pulled out from the ink sheet roll 1, the ink sheet roll 1 rotates with both end surfaces slidingly in contact with the left and right reel plates 34, 39.

Also, when replacing the ink sheet roll 1, the holding part 37 is moved to the right against the pressing force of the spring 41 to make the distance between the left holding body 31 and the right holding body 32 larger than the length of the ink sheet roll 1. shall be. When the ink sheet roll 1 is replaced in such a state, the core 2 of the ink sheet roll 1 is attached to the left and right holders 31 and 32.
It is held in place.

(c) Problems to be solved by the invention By the way, the core 2 of the ink sheet roll 1 is
Generally, they are made of paper, and their inner diameters vary. As shown in FIG. 4, the left locking part 3
If the inner diameter of the core 2 is larger than the diameter of the right locking portion 40, the ink sheet roll 1 will wobble and the amount of the ink sheet pulled out will be uneven. In addition, the core 2 is damaged at the left locking portion 35 (or right locking portion 40), and the rotational load on the ink sheet roll 1 cannot be kept constant at all times, resulting in a change in the pulling force of the ink sheet. do. Therefore, the conveyance accuracy of the ink sheet is adversely affected.

This invention was made in view of these points,
The purpose of this is to make the ink sheet roll easily attachable and detachable, and to stabilize the drawing of the ink sheet from the ink sheet roll to improve the conveyance accuracy of the ink sheet.

(d) Means for solving the problem The present invention consists of a platen and a thermal head, one of which is fixed, through which the ink sheet pulled out from the ink sheet roll is inserted under pressure together with the recording paper;
The other is a pair of reel plates elastically biased in one direction so as to be retractable, and the other is inserted from the end of the core of the ink sheet roll, and its diameter changes according to the inner diameter of the core. a sheet roll mounting tool comprising a protrusion that is integrally formed with the protrusion, a plate part that is integrally formed with the protrusion and that is in contact with the reel plate and coaxially engaged with the reel plate, and an engaging part that engages with the core of the ink sheet roll. and a friction sheet inserted between the reel plate and the plate portion of the sheet roll mounting jig.

(e) Effect The present invention involves attaching to the sheet roll a sheet roll mounting jig having a protrusion whose diameter can change according to the inner diameter of the core of the sheet roll, and holding the sheet roll in such a state. It is rotatably held by a mechanism.

(F) Embodiment FIG. 1 is a perspective view showing an embodiment of the present invention. Reference numeral 1 designates an ink sheet roll having an ink sheet 1a wound around a core 2, and only the left end portion thereof is shown in the figure. A small notch 2a is formed in the end face of the winding core 2. 3 is a sheet roll mounting jig, which is a feature of the present invention, and is made of, for example, a plastic molded product. Such sheet roll mounting jig 3
is a middle plate (plate part) 4 having a circular opening 4a in the center.
, a cylindrical body (protrusion) 5 provided on the disk 4 substantially coaxially with the circular opening 4a, and a protrusion (engaging portion) 6 provided on the surface of the disk 4 on the outside of the cylindrical body 5. Become. In this embodiment, the cylindrical body 5 has four notches 5a, 5a, . . . in the axial direction of the cylinder, and its outer diameter can be changed. The diameter is larger than the inner diameter.

Reference numeral 7 denotes a left holder fixed to the recording device, and the left holder 7 includes a fixed shaft 8, a left reel plate 9 attached to the tip of the fixed shaft, and one surface of the left reel plate. It consists of a locking part 10 provided protrudingly from the top.
The outer diameter of the locking portion 10 is approximately the same as the diameter of the circular opening 4a of the sheet roll mounting jig 3. Reference numeral 11 denotes a ring-shaped friction sheet made of synthetic leather or the like and adhered to one surface of the left reel plate 9.

Note that the right end portion of the ink sheet roll 1 is held by a right holder having the same structure as that shown in FIG. 3.

Thus, sheet roll mounting jigs 3 are mounted on both ends of the core 2 of the ink sheet roll 1. The outer diameter of the cylindrical body 5 of the sheet roll mounting jig 3 is
It changes according to the inner diameter of and becomes the same as this inner diameter.
In addition, a projection 6 is provided in the notch 2a provided in the winding core 2.
By engaging these, the sheet roll mounting jig 3 becomes integrated with the ink sheet roll 1.

In this state, the disc 4 of the sheet roll mounting jig 3
The disc 4 is placed in contact with the reel plate 11 and the circular opening 4a of the sheet roll mounting jig 3 is fitted into the locking portions 10 of the left holder 7 and the right holder (not shown). The sheet roll 1 is held coaxially with the reel plate 11. Then, when the ink sheet 1a is pulled out from the ink sheet roll 1, the ink sheet roll 1 rotates together with the sheet roll mounting jigs 3 at both ends thereof.

As described above, since the ink sheet roll 1 is attached to the holder via the sheet roll attachment jig 3, the ink sheet roll 1 is always attached to the holder without wobbling, regardless of variations in the inner diameter of the core 2. installed in the same condition.

Furthermore, as described above, as the ink sheet roll 1 is always mounted in the same state, the friction sheet 11 inserted between the sheet roll mounting jig 3 and the reel plate 9 is pressed and held by the left and right holders. A predetermined amount of braking force is always applied to the ink sheet roll 1 through a sheet roll mounting jig 3. Therefore, a constant back tension is always applied to the ink sheet 1a pulled out from the ink sheet roll 1, and the ink sheet 1a
It is transported without sagging.

(g) Effects of the invention According to the invention, it is possible to easily load and unload the ink sheet roll by simply moving one reel plate slightly backward.
Regardless of variations in the inner diameter of the core of the ink sheet roll, the ink sheet roll can be stably held without damaging the ends of the core, and the ink sheet roll can be held at a specified level with respect to the ink sheet roll. It is possible to provide a thermal transfer printer that can reliably apply a back tension of 1,000 yen, draw out an ink sheet with high precision, and perform recording without deteriorating print quality.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
4 to 4 show a conventional example, FIG. 2 is a schematic perspective view, FIG. 3 is a partial sectional view, and FIG. 4 is a sectional view of a main part. 1... Ink sheet roll, 3... Sheet roll mounting jig, 7... Left holding body.

Claims (1)

[Scope of utility model registration request] a platen and a thermal head through which an ink sheet pulled out from an ink sheet roll is inserted under pressure together with a recording paper; a pair of reel plates, one of which is fixed and the other of which is retractably biased in the one direction; a protrusion that is inserted from the end of the core of the ink sheet roll and whose diameter changes according to the inner diameter of the core; a protrusion that is integrally formed with the protrusion, faces the reel plate, and is coaxially engaged with the reel plate; A sheet roll mounting jig consisting of a plate portion to be mated and an engaging portion that engages with the core of the ink sheet roll, and a friction plate inserted between the reel plate and the plate portion of the sheet roll mounting jig. A thermal transfer printer characterized by comprising a sheet.