JP2565494B2 - Thermal transfer printing mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention uses a frame-sequential ink sheet and a heat-sensitive line head to thermally transfer a plurality of colors onto an image-receiving paper to obtain a color image. The present invention relates to a printing mechanism, and more particularly to a thermal transfer printing mechanism aiming at miniaturization and improvement of heat radiation from the heat-sensitive line head.

[Conventional technology]

Conventionally, a thermal transfer printing mechanism used to obtain a color image using a frame sequential ink sheet thermal line head is disclosed in Japanese Patent Publication No. 50-38029 and Japanese Patent Publication No. 56-6859. Is provided movably with respect to a carrier such as a chassis, and at the time of thermal transfer onto an image receiving paper, the heat-sensitive line head is pressed against the platen side by some means for printing. As means for carrying out this, use a cylindrical platen roll having a peripheral length larger than the longitudinal length of the image receiving paper, or sandwich the image receiving paper between a pinch roller and a small diameter platen roller, The image receiving paper is reciprocated for the number of times of printing.

[Problems to be solved by the invention]

The above-mentioned conventional technology does not consider effective heat dissipation when the heat-sensitive line head is large-sized or when the power consumption per hour is increased. It was necessary to take measures such as providing a large heat dissipation fin, or providing a fan for the heat dissipation fin as needed. However, providing a large heat-dissipating fin on the heat-sensitive line head, which is a movable part,
There is a problem that the moving means of the heat-sensitive line head is enlarged. Further, usually, there are ten to several tens of wires laid on the heat-sensitive line head, and from this point also, providing the heat-sensitive line head on the movable side makes the wire-wiring treatment difficult.

Incidentally, the drum type one provided with a platen roller having a peripheral length larger than the length of the image receiving paper leads to an increase in size of the thermal transfer printing mechanism with the increase in size of the image receiving paper.
The configuration in which the image receiving paper is reciprocally moved by using the pinch roller is to increase the printing time from the start of printing to the end of printing.

The present invention solves the above-mentioned problems of the prior art, provides good heat dissipation from the heat-sensitive line head, facilitates wiring to the heat-sensitive line head, and is small in size and has a short printing time. The purpose is to provide.

[Means for solving problems]

In order to achieve the above object, the structure of the thermal transfer printing mechanism according to the present invention is such that a thermal line head fixed to a chassis, a platen roller in pressure contact with the thermal line head, and at least a part of the circumference of the platen roller. A guide plate provided with a gap so as to cover it, a paper feeding / discharging guide for restricting the feeding / discharging of the image receiving paper to / from the gap by the guide plate, and the sheet are conveyed between the platen roller and the thermal line head. An ink sheet which is housed in an ink sheet cartridge and is applied with a plurality of colors of ink in a frame-sequential manner, and which passes between the ink sheet and the platen roller, and along a transport path longer than the transport direction length of the single-leaf image receiving paper. In a thermal transfer print mechanism having a transport mechanism capable of transporting image receiving paper and a chassis supporting these,
The ink sheet cartridge is attachable / detachable in the axial direction of the platen roller, and the transport mechanism is at least in the closed image receiving sheet transport path constituted by the platen roller, the guide plate, and the paper feed / discharge guide,
Color recording is performed while circulating the image receiving paper, and the ink sheet cartridge is attached / detached between the heat sensitive line head and the platen roller at a printing position where the platen roller is brought into pressure contact with the heat sensitive line head. The platen roller moving mechanism that can be positioned at two positions apart from the heat-sensitive line head as far as possible is provided on the chassis.

 The details are as follows.

The heat-sensitive line head is fixed to the shear and the platen roller is movable. The platen roller is fixed to the swing arm that is swingable around the main shaft of the shear. In addition to being movable with respect to the heat-sensitive line head, the conveyance path of the image receiving paper is an elliptical conveyance path having the center of the conveyance roller fixed to the main shaft and the center of the platen roller as both centers. By allowing the circular conveyance path to take two positions, a printing position and a separating position, together with the swing arm, even when the platen roller is on the movable side, the platen roller takes the printing position. Sometimes
The image receiving paper can be fed and discharged.

[Action]

Since printing can be carried out in a frame-sequential manner by carrying the image receiving paper in one direction, the printing time is short. Further, since the relative position of one of the axes forming the conveyance path of the image receiving paper, that is, the main shaft, does not change with respect to the shear, the consistency between the conveyance mechanism and the paper feed mechanism fixed to the shear is ensured. Do not disturb. Then, a platen roller is attached to the other shaft, that is, a platen shaft, the platen roller is swingable around the main shaft, and the platen roller is pressed against and separated from the heat sensitive line head, so that the heat sensitive line head is fixed. The heat-sensitive line head can be provided on the side to simplify the wiring process to the heat-sensitive line head, and improve heat dissipation by fixing the heat-sensitive line head to, for example, a shear. It should be noted that, by making the conveyance path of the image receiving paper an elliptical shape, compared to the drum type with the same circumference,
The thermal transfer printing mechanism is further miniaturized.

〔Example〕

Hereinafter, the present invention will be described with reference to the drawings based on embodiments.

FIG. 1 is a schematic side view of a thermal transfer printing mechanism according to an embodiment of the present invention (however, with a housing removed), FIG.
FIG. 1 is a side view showing a drive unit for the ink sheet cartridge and the image receiving paper conveying mechanism in FIG. 1, and FIG.
FIG. 4 is a plan view showing the details of the platen roller moving mechanism in the figure, FIG. 4 is a perspective view showing the details of the paper discharge mechanism in FIG. 1, and FIG. 5 is a development view showing the main part of the ink sheet in FIG. FIG. 6 is a cross-sectional view showing details of an attachment state of the heat-sensitive line head in FIG. 1 to the shear.

An outline of the thermal transfer printing mechanism will be described with reference to FIG. 1. The thermal transfer printing mechanism includes a heat sensitive line head 1, a platen roller 10 in pressure contact with the heat sensitive line head 1, the platen roller 10 and the heat sensitive line head 1. The ink sheet 3 that is conveyed to the space between the ink sheet 3 and the platen roller 10 is conveyed along the conveyance path P that passes between the ink sheet 3 and the platen roller 10, for example, with the longitudinal direction and the conveyance direction aligned. Transport mechanism T that can
And a shear 2 for carrying them, in which the heat-sensitive line head 1 is fixedly provided to the shear 2.
The platen roller 10 is separated from the heat-sensitive line head 1 by a printing position (a position indicated by a solid line) where the platen roller 10 is pressed against the heat-sensitive line head 1 and the ink sheet 3 is detachable between the heat-sensitive line head 1 and the platen roller 10. The platen roller moving mechanism 19 that can be positioned at two separate positions (the position indicated by the broken line) is the shear 2
Is a thermal transfer printing mechanism provided in the.

 The details of the thermal transfer printing mechanism will be described below.

Reference numeral 2 denotes a chassis having a bottom plate 2b on which a head seat portion 2a (details described later) that is convex upward is formed. Reference numeral 1 denotes a so-called heat generating element in which a plurality of heating elements are arranged in the edge portion of the head in a direction perpendicular to the paper surface. This is an edge type heat-sensitive line head, and the heat-sensitive line head 1 is fixed to the head seat portion 2a. Reference numeral 3 denotes an ink sheet (details described later) coated with a coloring material such as a sublimable dye or a molten pigment, and the ink sheet 3 is housed in an ink sheet cartridge 6 for convenience of attachment / detachment. That is, the ink sheet 3 is wound in the direction C from the supply shaft 4 of the ink sheet cartridge 6 through the connecting portion 6a and the winding shaft 5. The supply shaft 4 and the take-up shaft 5 are mounted on a supply reel stand 46 and a take-up reel stand 45 of a drive device 49 (details will be described later). Reference numeral 7 denotes a main shaft rotatably supported by the shear 2, and the main shaft 7 is provided with a platen roller moving mechanism 19 (described later in detail) having the main shaft 7 as a swing center. The platen shaft 9 of the platen roller 10 is rotatably attached to the tip of the swing arm 40 of the mechanism 19. The platen roller moving mechanism 19 will be described in detail with reference to FIG. 3. The platen roller moving mechanism 19 has a main shaft 7 and a pair of swing arms 40 having the main shaft 7 as a swing center. The swing arm 40 is rotatable about a first gear 54 fixed to the main shaft 7, a second gear 51 fixed to the platen roller shaft 9, and an idler shaft 52 on the swing arm 40. The first and second gears 54,5 are supported by the bearings.
A rotation transmission mechanism composed of an idler gear 53 meshing with 1 is provided, and rotation of the main shaft 7 is controlled by the platen roller 10.
Can be transmitted to. Then, the platen roller moving mechanism 19 is oscillated by an ordinary link mechanism (or solenoid mechanism), so that the platen roller 10 is brought into pressure contact with the heat-sensitive line head 1 at a printing position (solid line position in FIG. 1). ) And a separated position (position indicated by a broken line in FIG. 1) apart from the above).

T is a conveying roller 8 fixed to the main shaft 7, and a platen belt 11 made of an elastic material such as rubber and stretched between the conveying roller 8 and the platen roller 10 to convey the image receiving paper. A drive mechanism for the main shaft 7
When driven by the large gear 44 ′ of 49, the transport roller 8 rotates integrally therewith, and the platen roller 10 rotates in the same direction as the transport roller 8 via the platen belt 11.
P is an oval-shaped conveyance path of the image receiving paper along the platen belt 11 of the conveyance mechanism T.

Reference numeral 12 denotes a lower guide plate provided with a slight clearance with respect to a lower outer peripheral surface of the platen belt 11, and the lower guide plate 12 has a pair of swing arms via a stay (not shown). It is connected to the roller 40 and prevents the transport roller 8 and the platen roller 10 from twisting with respect to each other.

The platen belt 11 creates a constant arcuate locus around the main shaft 7 supported by the shear 2 regardless of the swing motion of the swing arm 40. 14 has a slight clearance with respect to this arc-shaped trajectory,
It is a paper feed / discharge guide provided so as to be swingable around a center. The bearing 13 (not shown) is swingably supported around the main shaft 7, and can be locked to the swing arm 40 by a locking mechanism (not shown). Sometimes, it is an upper guide plate (details will be described later) provided so as to maintain a slight clearance with the platen belt 11. 16
Is rotatably supported by the chassis 2 and is a platen belt.
The lower guide roller 17 which is in pressure contact with the conveying roller 8 via 11 is rotatably attached to the upper guide plate 13, and the upper guide roller 18 which is in pressure contact with the platen roller 10 via the platen belt 11 is On the winding shaft 5 side near the heat-sensitive line head 1, the shear 2 is rotatably supported by the sheath 2.
When the platen roller 10 is in the printing position (solid line position in FIG. 1), it is a peeling roller that is in pressure contact with the platen roller 10.

Reference numeral 20 is an image receiving paper, and the image receiving paper 20 is stacked on a push-up plate 22 in a supply tray 21 provided in a housing (not shown). A push-up pin 24 is supported by a push-up shaft 23 provided on the chassis 2, and the push-up pin 24 is rotated by a link mechanism (not shown) to move the push-up plate 22. Can be pushed up. Numerals 25 and 26 are pick-up rollers and feeding rollers rotatably supported by the chassis 2, respectively, and numeral 27 is a conveyor belt which is hung around these rollers 25 and 26 in an elliptical shape.
Is made of a high friction material such as rubber, a flexible material having a rough abrasive grain layer on its surface, or a flexible material having many thin needles embedded therein. 28 is a reverse roller which is swung by a swing mechanism (not shown) provided in the chassis 2, and is pressed against the conveyor belt 27 when reaching the position of the broken line and can be rotated in the direction of arrow E, Reference numerals 29 and 30 denote a lower paper feed guide member and an upper paper feed guide member fixed to the chassis 2, respectively.

The reference numeral 33 designates a sheet discharge roller which is supported by the chassis 2 and rotates in the direction of arrow F by a sheet discharge roller drive mechanism (not shown). The reference numeral 34 designates a driven roller which is in pressure contact with the sheet discharge roller 33. Is a paper discharge tray fixed to the housing. Reference numerals 31 and 32 denote a lower paper ejection guide and an upper paper ejection guide, which are fixed to the chassis 2, respectively, and are arranged so that one end of these is located on the paper ejection guide 14 side and the other end is located on the paper ejection roller 33 side. Are provided, and a substantially uniform clearance is provided between them in the longitudinal direction.

The details of the head seat portion 2a will be described with reference to FIG. 6. The head seat portion 2a is formed on the bottom plate 2b of the chassis 2 so as to be convex upward, and has a slightly shallower portion. Yes, heat sensitive line head 1 in the shallowed part
Has been fixed. Reference numeral 2c is a hole for air circulation formed near the head seat portion 2a of the bottom plate 2b. 55 is a wiring connected to each heating element of the thermal line head 1.

The details of the ink sheet 3 will be described with reference to FIG. 5. The ink sheet 3 is an ink sheet for three-color printing, and has a coating length substantially equal to the circumferential length of the platen belt 11 and a cyan color, Magenta and yellow are applied in a frame-sequential manner and repeatedly in the longitudinal direction.

The details of the drive device 49 will be described with reference to FIG. 2. Reference numeral 50 is a motor mounted on the chassis 2, 41 is a worm gear provided on the shaft of the motor 50, and 42 is meshed with the worm gear 41. A helical gear, 43 is a take-up gear that meshes with the helical gear, 44 is a take-up clutch coaxial with the take-up gear 43, and 45 is a take-up reel stand having a convex portion formed in the radial direction. A hole (not shown) having a concave portion of the take-up shaft 5 of the ink sheet cartridge 6 is fitted into the convex portion of the take-up reel stand 45, and a driving force is applied to the take-up shaft 5. You are able to do it. The supply shaft 4 of the ink sheet cartridge 6 is adapted to be fitted into the convex portion of the supply reel base 46 by the concave portion of the hole, and the ink sheet cartridge 6 is arranged in the axial direction of the main shaft 7 (perpendicular to the paper surface). direction)
Put on and take off. The supply reel base 46 receives a sliding load from the shear 2 via the supply clutch 47, and has a tooth portion 46b and a stopper 48 provided around the supply reel 47 (the stopper 48 is swingably provided on the shear 2). It becomes impossible to rotate when engaged with. On the other hand, the helical gear
A small gear 43 'is fixed to the shaft 42 coaxially therewith, and this small gear 43' is meshed with a large gear 44 'fixed to the main shaft 7 to apply a driving force to the main shaft 7. You can do it.

In addition, the details of the upper guide plate 13 and the paper feed / discharge guide 14,
Explaining with reference to FIG. 4, a plurality of notches 13a are provided at the rear end 13b of the upper guide plate 13, and the same number of claw portions 14a provided in the paper feeding / discharging guide 14 are inserted therein. You are able to do it. The claw portions 14b and 14c provided at both ends of the paper feed / discharge guide 14 are slightly longer than the claw portion 14a. In addition, a plurality of convex portions 31a bent slightly downward are formed on the front surface (right side in FIG. 4) of the lower paper ejection guide 31, and each of these convex portions 31a is a claw of the paper ejection guide 14. It is getting into the space.

The operation of the thermal transfer printing mechanism thus configured will be described.

When not operating, the platen roller moving mechanism 19 is in the standby position, that is, the separated position, as shown by the broken line in FIG.
Along with this, the upper guide plate 13, the platen roller 10, the lower guide plate 12, etc. are also in the separated positions shown by the broken lines. Therefore, between the heat-sensitive line head 1 and the lower guide plate 12, there is a space in which the connecting portion 6a for connecting the supply shaft 4 and the take-up shaft 5 of the ink sheet cartridge 6 can freely move in the direction perpendicular to the paper surface. .

In the state described above, the ink sheet cartridge 6 is attached to the drive device 49. That is, the supply shaft 4 of the ink sheet cartridge 6 is fitted to the supply reel stand 46 of the drive unit 49, and the take-up shaft 5 is fitted to the take-up reel stand 45.

When the platen roller moving mechanism 19 is rotated by the link mechanism after the ink sheet cartridge 6 is mounted on the drive device 49 in this manner, the swing arm 40 causes the swing arm 40 to move.
And the platen roller 10 is pressed against the printing position (the position shown by the solid line).

 The paper feeding operation will be described.

The image receiving paper 20 stacked in the paper feed tray 21 is pushed up via the push-up plate 22 by the push-up pin 24 being rotated by the link mechanism as shown by the broken line in FIG. The uppermost one comes into contact with the conveyor belt 27. The conveyor belt 27 is rotated in the direction of arrow D by a rotation source (not shown), the image receiving paper 20 is pulled out by friction, and the lower paper feed guide material 29 and the upper paper feed guide material 30 are wound up. , The tip of the lower guide roller 16 comes into contact with the platen belt 11.

As shown in FIG. 2, the rotation of the motor 50 causes the small gear
43 'rotates in the G direction, and the main shaft 7 rotates in the A direction. Therefore, as shown in FIG. 1, the conveying roller 8 fixed to the main shaft 7 rotates in the direction of arrow A, and the first gear 54, the idler gear 53, the second gear 51, and the platen shaft 9 are rotated.
At the same time, the platen roller 10 also rotates in the direction of arrow B via (see FIG. 3).

As a result of the above, the platen belt 11 rotates in an elliptical shape, and the lower guide roller 16 in pressure contact with this also rotates. Therefore, the leading edge of the image receiving paper 20 is the lower guide plate 12 and the platen belt.
Go through the clearance between 11 and. The coefficient of friction between the heat-sensitive line head 1 and the ink sheet 3 is sufficiently small, and the coefficient of friction between the ink sheet 3 and the platen belt 11 is large. Therefore, due to the rotation torque of the take-up reel stand 45 in the direction of arrow C, The ink sheet 3 that receives the tension moves at the same speed as the flatten belt 11. Therefore, the image receiving paper 20 passes through the pressure contact portion with the heat-sensitive line head 1. At this time, the heating element of the heat-sensitive line head 1 selectively generates heat via the wiring 55 according to the print data input in advance to the control device (not shown), and the heat causes pressure contact with this. The ink of the ink sheet 3 is melted or sublimated, and this is transferred to the image receiving paper 20 to form a desired print. Even if the ink sheet 3 is moved in the direction of the take-up shaft 5 by the peeling roller 18, the image receiving paper 20 is relatively hard, so the upper guide plate 13
Is transported to and from.

The paper feeding / discharging guide 14 has a clearance with respect to the platen belt 11 as shown by the solid line in FIG. 1, and as shown in FIG. 4, the notch 13a at the rear end of the upper guide plate 13 is provided.
Since the claw portion 14a of the paper feeding / discharging guide 14 has entered,
The image receiving paper 20 is conveyed along the conveying roller 8 and reaches the lower guide roller 16 again, and thereafter, the image receiving paper 20 is rotated a necessary number of times, three times in this embodiment since it is a three-color print.

Since the circumference of the platen belt 11 is set to be slightly longer than the length of the image receiving paper 20, the front end and the rear end of the image receiving paper 20 are adjacent to each other and pass through the heat sensitive line head 1. The thermal transfer printing mechanism can print a plurality of colors in a shorter time than the method of reciprocating only three times in the case of three-color printing.

 Next, the paper discharge operation will be described.

While printing the last color, i.e. yellow,
When the rear end enters the paper feeding / discharging guide 14, the paper feeding / discharging guide 14 swings around the paper feeding / discharging guide shaft 15 to a position indicated by a broken line in FIG. 1 by a link mechanism (not shown). . At this time, since the claws 14b and 14c at both ends of the paper feeding / discharging guide 14 are slightly longer than the other claws 14a, the main shaft 7 is more than the surface of the platen belt 11.
The claw portion 14a is located closer to the platen belt 11 than the rear end 13b of the upper guide plate 13. Since the front end of the image receiving paper 20 is elastic, the image receiving paper 20 is near the rear end 13b which forms an arc around the main shaft 7 of the upper guide plate 13.
Proceed along the inner surface of the sheet, and then come out to the upper surface of the sheet feeding / discharging guide 14. In particular, by setting the width of the platen belt 11 to be smaller than the width of the image receiving paper 20 and larger than the width of the actual print portion, the claws 14b and 14c at both ends of the paper feeding / discharging guide 14 are made to be the image receiving paper 20.
In order to scoop up the non-printing portion (so-called ear or margin), the transfer of the image receiving paper 20 to the upper surface of the paper feed / discharge guide 14 is ensured.

The image receiving paper 20 that has emerged on the upper surface of the paper supply / discharge guide 14 reaches the lower paper discharge guide material 31. As shown in FIG. 4, the lower discharge guide material 31
Since a plurality of convex portions 31a bent slightly downward are provided at the front end of the sheet feeding device, and each of them is inserted between the claws of the sheet feeding / discharging guide 14, the sheet feeding / discharging guide 14 is indicated by a broken line in FIG. Even when the image receiving sheet 20 is moved to the indicated sheet discharging position, the leading edge of the image receiving sheet 20 is guided to the upper surface of the lower sheet discharging guide member 31.

After that, the image receiving paper 20 will be the lower discharge guide material 31 and the upper discharge guide material.
32, and is guided between the paper discharge roller 33 rotating in the direction of arrow F in FIG. 1 and the driven roller 34 to form a paper discharge tray.
The paper is ejected into 35. In this way, when the second and subsequent image receiving papers 20 are fed, printed, and discharged, and the desired number of sheets are stored in the discharge tray 35, the thermal transfer print mechanism is turned off.

 According to the embodiment described above, the following effects can be obtained.

(A) Since the heat-sensitive line head 1 is fixed to the head seat portion 2a provided on the bottom plate 2b of the chassis 2, the heat generated by the print from the heat-sensitive line head 1 has a large heat capacity and is always stored in relatively low temperature air. It is quickly transmitted to the exposed chassis 2 and is exhausted. Therefore, it is not necessary to provide a fan for exhaust heat, and the thermal transfer printing mechanism is downsized. The wiring 55 to the heat-sensitive line head 1 is not subjected to repeated bending. Therefore, it is sufficient to use an inexpensive ordinary wire rod without using a particularly expensive flexible pattern, and the wiring process becomes easy.

(B) A platen belt 11 (the circumference of the platen belt 11 is slightly longer than the length of the image receiving paper 20 in the longitudinal direction), which is formed by extending the conveying path P of the image receiving paper 20 between the conveying roller 8 and the platen roller 10. Since it has an oval shape along the circumference, the thermal transfer printing mechanism is downsized as compared with the drum type having the same circumference as the circumference. The print time is shorter than the configuration in which the pinch rollers are used to reciprocate.

(C) Since the attachment / detachment direction of the ink sheet cartridge 6 coincides with the axial direction of the platen roller 10 and the elliptical conveyance path P is made swingable around the main shaft 7 by the platen roller moving mechanism, the platen roller When 10 is in the separated position, the platen roller of the thermal line head 1
Drive the ink sheet cartridge 6 from between 10 and
Can be attached to and detached from 49. Since the movement amount of the transport path P can be reduced and the positional accuracy due to the swing is improved, the peripheral length of the transport path P is accurately maintained even before and after the platen roller is moved, and the feeding / discharging fixed to the chassis 2 is performed. The image receiving paper 20 can be smoothly fed to and discharged from the conveyance path P without disturbing the consistency between the paper mechanism and the conveyance path P.

In this embodiment, the heat-sensitive line head 1 is directly fixed to the head seat portion 2a. However, if the heat-sensitive line head 1 is fixed in the middle through a member having good heat conduction, for example, an aluminum plate, the heat-sensitive line head 1 is discharged. The heat is further improved. Further, a heat radiation fin may be attached to the back surface of the head seat portion 2a. An attachment position adjusting mechanism may be interposed between the heat-sensitive line head and the head seat portion 2a so that the attachment position of the heat-sensitive line head can be adjusted.
The easiest way to adjust the mounting position is to make an adjustment hole in the head seat portion 2a, insert a driver or the like into the adjustment hole, and use the driver to pry.

Furthermore, although the platen shaft 9 is rotatably attached to the swing arm 40 in the present embodiment, it may be fixed. In that case, replace the platen roller 10 with the platen shaft 9
Must be rotatably attached to.

Furthermore, in the present embodiment, the conveyance path P of the image receiving paper is an elliptical conveyance path along the platen belt 11 which is stretched between the conveyance roller 8 and the platen roller 10.
A rubber ring or the like is attached to each of the rollers 8 and 10, and intermediate guide plates are arranged above and below the rollers 8 and 10 so that the conveyance roller 8 and the center and the center of the platen roller 10 are both centers. You may make it form an oval shape conveyance path.

 Another embodiment will be described.

FIG. 7 is a side view of essential parts of a thermal transfer printing mechanism according to another embodiment of the present invention.

In FIG. 7, the same parts as those in FIG. 1 are designated by the same reference numerals. And 1A is in the center of the head,
The so-called center type heat-sensitive line head, 10A, in which a plurality of heating elements are arranged in the direction perpendicular to the paper surface, has a circumferential length slightly longer than the length of the image receiving paper and the surface is covered with an elastic material such as rubber. The platen roller 10A is rotatably attached to the tip of the swing arm 40 via the platen shaft 9.

This embodiment is different from the embodiment according to FIG. 1 in that the image receiving paper conveyance path P'is substantially circular along the outer periphery of the platen roller 10A.

By the swinging operation of the platen roller moving mechanism 19, the platen roller 10A is moved between the printing position (solid line position) where the platen roller 10A is brought into pressure contact with the heat sensitive line head 1A and the heat sensitive line head 1A and the platen roller 10A. There is no difference from the embodiment according to FIG. 1 described above in that it can be positioned at two positions, that is, the separated position (broken line position), which is separated from the heat-sensitive line head 1A as much as possible. The paper feeding / discharging operation is exactly the same.

In this embodiment, since the heat-sensitive line head 1A is fixedly provided on the head seat portion 2a of the chassis 2, the thermal transfer printing mechanism can be made smaller than the conventional one, and the heat discharging property from the heat-sensitive line head 1A is improved, and This has the effect of facilitating the wiring process.

〔The invention's effect〕

As described in detail above, according to the present invention, a heat transfer printing mechanism that provides good heat dissipation from the heat-sensitive line head, facilitates the wiring process to the heat-sensitive line head, and is small in size and has a short printing time is provided. be able to.

[Brief description of drawings]

FIG. 1 is a schematic side view of a thermal transfer printing mechanism according to an embodiment of the present invention (however, with a housing removed), and FIG. 2 is a conveyance of ink sheet cartridge and image receiving paper in FIG. FIG. 3 is a side view showing a driving device of the mechanism, FIG. 3 is a plan view showing details of the platen roller moving mechanism in FIG. 1,
FIG. 4 is a perspective view showing details of the paper discharge mechanism in FIG. 1, FIG. 5 is a development view showing a main part of the ink sheet in FIG. 1, and FIG. 6 is a heat-sensitive line head in FIG. FIG. 7 is a cross-sectional view showing the details of the state of attachment to the chassis, and FIG. 7 is a side view of the essential parts of a thermal transfer printing mechanism according to another embodiment of the present invention. 1,1A: Thermal line head, 2 ... Chassis, 2a ... Head seat, 2b ... Bottom plate, 3 ... Ink sheet, 7 ... Spindle, 8 ... Conveying roller, 10, 10A ... Platen roller, 11
...... Platen belt, 19 ...... Platen roller moving mechanism,
40 …… Rotating arm, 51 …… Second gear, 52 …… Idler shaft, 53 …… Idler gear, 54 …… First gear, P, P ′ ……
Conveyance path for image receiving paper, T ... Conveying mechanism for image receiving paper.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 60-52374 (JP, A) JP 59-192587 (JP, A) JP 57-69079 (JP, A) JP 63- 5976 (JP, A) Actual public 37-18502 (JP, Y1)

Claims (5)

(57) [Claims] 1. A heat-sensitive line head fixed to a chassis,
A platen roller that is in pressure contact with the heat-sensitive line head, a guide plate provided with a gap so as to cover at least a part of the circumference of the platen roller, and the supply and discharge of image receiving paper to and from the gap by the guide plate are restricted. A sheet feeding / discharging guide, an ink sheet that is conveyed between the platen roller and the heat-sensitive line head, is stored in an ink sheet cartridge, and ink of a plurality of colors is applied in a surface sequential manner; the ink sheet and the platen roller. In a thermal transfer printing mechanism having a transport mechanism capable of transporting the image receiving paper along a transport path longer than the transport direction length of the single-leaf image receiving paper, and a chassis supporting these, the ink sheet The cartridge is detachable in the axial direction of the platen roller, and the transport mechanism is at least the platen roller. Color recording is performed while the image receiving paper is circulated in the closed image receiving paper conveying path constituted by the guide plate and the paper supply / discharge guide, and the platen roller is pressed against the thermal line head. A platen roller moving mechanism capable of being positioned at two positions, that is, an image printing position and a position separated from the heat sensitive line head so that the ink sheet cartridge can be attached to and detached from the heat sensitive line head and the platen roller. A thermal transfer printing mechanism, wherein: 2. A thermal transfer printing mechanism according to claim 1, wherein the heat-sensitive line head is fixed to a head seat portion provided on the bottom plate of the chassis through a member having good heat conduction. 3. A platen roller moving mechanism having a main shaft provided on a chassis and a pair of swing arms having the main shaft as a swing center. A platen roller is provided at the tip of the swing arm. The thermal transfer printing mechanism according to claim 1, wherein the thermal transfer printing mechanism is rotatably attached. 4. A main shaft is made rotatable and a conveying roller is fixed to the main shaft, and a swinging arm is provided with a rotation transmitting mechanism for transmitting the rotation of the main spindle to a platen roller. 4. The thermal transfer printing mechanism according to claim 3, wherein an elliptical conveying path is formed with the center of the conveying roller and the center of the platen roller as both centers. 5. A conveyance path for receiving an image receiving paper is an elliptical conveyance path along a platen belt which is stretched between a conveyance roller and a platen roller.
The thermal transfer printing mechanism according to the item.