JP4455299B2 - Printing method of thermal transfer printer - Google Patents

Description

  The present invention relates to a printing method for a thermal transfer printer, and more particularly to a printing method for a thermal transfer printer that senses the print start position of an ink ribbon during printing.

The printing method of the conventional thermal transfer printer 31 will be described based on Patent Document 1. As shown in FIG. 9, the thermal transfer printer 31 can be mounted with a printer main body 31a and a ribbon cassette 39 to be described later in the printer main body 31a. A cassette mounting portion 31b is formed.
A platen roller 32 is disposed in the printer main body 31a, and a thermal head 33 is disposed above the platen roller 32.
Further, between the thermal head 33 and the platen roller 32, the recording paper 34 is fed in the direction of arrow A and can be conveyed.

The recording paper 34 is made of thick paper such as photographic paper on which a color image such as a photograph can be printed.
The thermal head 33 is supported by a head mounting base 35, and the head mounting base 35 is attached to a head lever 36. The head lever 36 is rotated with the support shaft 37 as a fulcrum, so that the thermal head 33 can come in contact with and separate from the platen roller 32 (head up / down).

Further, when a ribbon cassette 39 (to be described later) is mounted on the cassette mounting portion 31b with the thermal head 33 raised, the ink ribbon 38 is positioned between the platen roller 32 and the thermal head 33.
Both ends of the ink ribbon 38 are wound around a supply reel 39 a and a take-up reel 39 b and are stored in a ribbon cassette 39.

As shown in FIG. 10, the ink ribbon 38 is formed with an ink layer 38a coated with, for example, yellow (Y), cyan (C), and magenta (M) inks in order. The printing paper 34 is formed slightly longer than the printing range.
Two first markers 38b are formed in the transparent portion between the last C color ink layer 38a and the first Y color ink layer 38a, and the Y color ink layer 8a and One second marker 38c is formed between the M color ink layer 8a and the transparent portion between the M color ink layer 8a and the C color ink layer 8a. .

When the thermal head 33 is in the head-up state, the first marker 38b is detected by a ribbon sensor 42 described later, so that the print start position of the first Y-color ink layer 38a at the time of printing is determined on the recording paper 34. Ribbon sensing is performed to align with the print start position.
In addition, ribbon sensing of the M and C ink layers 38a is performed by the second marker 38c.
A transparent space portion 38d having a dimension B is formed between the first and second markers 38b and 38c and the ink layer 38a of each color.

Further, in the ribbon cassette 39, a relief groove 39d is formed on the left side of the partition wall 39e in the figure, and a winding port 39f is formed on the bottom side of the relief groove 39d in the upper part of the figure. A guide roller 39g made of a metal rod is rotatably supported on the side plate 39c in the vicinity of the winding port 39e.
The ink ribbon 38 that is in close contact with the recording paper 34 at the time of printing is peeled off from the thermal head 33 at a predetermined peeling angle, and can be taken up on a take-up reel 39b via a guide roller 39g.

Further, on the left side of the platen roller 32 in the figure, a paper feed roller 40 and a pressure contact roller 41 that is in pressure contact with the paper feed roller 40 are disposed, and a recording paper 34 is placed between the paper feed roller 40 and the pressure contact roller 41. It can be held and conveyed in the direction of arrow A.
When the ribbon cassette 39 is mounted on the cassette mounting portion 31b, the pressing roller 41 is positioned in the escape groove 39d.
Further, an optical ribbon sensor 42 is disposed in a portion where the escape groove 39d is located, and the light irradiated from the ribbon sensor 42 can be reflected on the partition wall 39e on the side facing the ribbon sensor 42. A reflective portion (not shown) having gloss is formed. In addition, the dimension from the heating element of the thermal head 33 in the head down state to the ribbon sensor 42 is the same as the dimension B of the space portion 38 d of the ink ribbon 38.

A printing method of such a conventional thermal transfer printer 31 will be described. First, with the thermal head 33 raised, the take-up reel 39b is driven to rotate and the ink ribbon 38 is taken up.
As a result, when the ribbon sensor 42 detects the first marker 38b and stops ribbon winding, the leading portion of the first Y-color ink layer 38a of the ink ribbon 38 becomes the heating element forming portion of the thermal head 33. The Y-color ink layer 38a is sensed by being aligned.

At the same time, the recording paper 34 fed between the thermal head 33 and the platen roller 32 in the head-up state has the front end 34a sandwiched between the paper feed roller 40 and the pressure roller 41, and the recording paper 34 is sensed. Is called.
Thereafter, the thermal head 33 is headed down, the recording paper 34 is conveyed in the direction of arrow A by the rotation of the paper feed roller 40, and the heat generating elements of the thermal head 33 are selectively heated based on the print information. The first Y ink is thermally transferred, and a Y color image is printed on the recording paper 34.

Thereafter, the thermal head 33 is headed up, the recording paper 34 is back-fed and sensing is performed again, and the take-up reel 39b is rotationally driven to wind up the ink ribbon 38, whereby the M color ink layer 38a is formed. The ribbon sensor 42 detects the second marker 38c and senses the M color ink layer 38a.
The thermal head 33 is then headed down, and an M color image is printed over the Y color image. Thereafter, the same operation is repeated, and the C color image is overprinted on the M color image, so that a desired color image can be printed on the recording paper 34.
JP 2002-144616 A

However, in the conventional printing method of the thermal transfer printer 31, the ink ribbon 38 is sensed by the ribbon sensor 42 disposed in the escape groove 39 d of the ribbon cassette 39 away from the heating element of the thermal head 33. The dimension B of the space portion 38d of the ink ribbon 38 corresponding to the dimension from the heating element to the ribbon sensor 42, which is a portion not subjected to printing, is long.
Therefore, the dimension from the first marker 38b to the second marker 38c of the ink ribbon 38 and the dimension from the second marker 38c of M color to the second marker 38c of C color are increased, It takes a long time to overlap and print a plurality of ink layers 38a, 38a of different colors on one recording paper 38, which hinders improvement in printing speed.
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and to provide a printing method for a thermal transfer printer that can improve the printing speed for recording paper by reducing the size of a portion that is not used for printing an ink ribbon.

As a means for solving the above problems, a printing method of a thermal transfer printer according to the present invention includes a thermal head attached to a thermal head support member via a thermal head mounting base and disposed so as to be able to contact and separate from a platen roller, and the thermal head An ink ribbon routed between the head and the platen roller, and an opening for the thermal head to face the platen roller is formed on the lower side of the cavity surrounding the thermal head mounting base, and independently A head guide that is movably disposed and is capable of pressing and releasing the recording paper against the platen roller in conjunction with the contact and separation of the thermal head with respect to the platen roller, and the recording paper when the head guide is printed In the conveyance direction of the A ribbon sensor capable of ribbon sensing by detecting reflected light reflected from the ink, and disposed opposite to the ribbon sensor with a conveyance path between the recording paper and the ink ribbon interposed therebetween, and irradiation of the ribbon sensor A thermal transfer printer including a reflecting plate capable of reflecting light, and a plurality of color ink layers used for color printing on each recording paper is longer than a printable range of the recording paper, shorter than the paper length, and A first marker that aligns the print start position of the ink layer with the thermal head is formed at the tip of the ink layer that is formed in order and used for printing the first color of the ink layer, A second marker for aligning the print start position of each ink layer with the thermal head is formed at the tip of each ink layer used for printing for the second and subsequent colors. Using the ink ribbon, the recording paper is conveyed forward and backward, the ink layers of a plurality of colors are overprinted by thermal transfer, and a blank portion is formed at least at the rear end of the recording paper. A printing method for printing a color image, wherein the first ribbon sensing for detecting the first marker raises the thermal head, raises the head guide and the ribbon sensor, and irradiates the ribbon sensor. Second ribbon sensing is performed by reflecting light on the reflector and detecting the second marker. The thermal head is lowered, the head guide and the ribbon sensor are lowered, and the ribbon sensor is irradiated. It is characterized in that the light is reflected by the margin part.

In the thermal transfer printer printing method of the present invention, the head guide has a first position where the head guide is largely separated from the platen roller when the thermal head is in a head-up state, and when the thermal head is in a head-up state. It can be positioned at a second position that is smaller than the platen roller than the first position, and a third position that presses the recording paper against the platen roller when the thermal head is in a head-down state. It is characterized by.
When there is no recording paper between the platen roller and the head guide, the head guide is positioned at the first position or the second position to perform the first ribbon sensing, and then the recording paper is used. , The thermal head is lowered, the head guide is positioned at the third position, and the first color image is printed on the recording paper. Thereafter, the head guide is moved to the third position. The second ribbon sensing is performed at the position.

Furthermore, in the printing method of the thermal transfer printer according to the present invention, in the case where continuous printing is performed on a plurality of recording sheets, the head guide performs the first ribbon sensing when the first first sheet is printed. The first ribbon sensing when the second and subsequent sheets are printed is performed when the head guide is positioned at the second position. And
  Further, the head guide is provided with a peeling roller on the downstream side of the ribbon sensor in the recording paper conveyance direction so that the ink ribbon that is in close contact with the recording paper during printing is peeled off by the peeling roller. It is characterized by that.

In the printing method of the thermal transfer printer of the present invention, a paper guide is disposed between the platen roller and a paper feed roller provided downstream in the conveyance direction of the recording paper, and the recording paper is bent downward. It is characterized by preventing the removal.
Further, the reflector is provided on the upper surface of the paper guide to prevent the recording paper from being bent downward, and when the recording paper is not fed, the reflector is provided on the upper surface. The first ribbon sensing is performed.

In the thermal transfer printer printing method of the present invention, since the ribbon sensor is disposed in the vicinity of the thermal head, the size of the ink ribbon from the first marker to the ink layer can be reduced to reduce the portion not used for printing. The winding time of the ink ribbon required for printing can be shortened.
Therefore, it is possible to shorten the time required for color printing in which different color ink layers are printed on a single recording sheet, thereby improving the printing speed.
Further, when the recording paper is not conveyed between the thermal head and the platen roller, the thermal head is raised and the irradiation light of the raised ribbon sensor is reflected by the reflecting plate to form the ink ribbon. When the recording paper is being transported between the thermal head and the platen roller by detecting the first marker, when the recording paper is being transported between the thermal head and the platen roller, the irradiation light of the ribbon sensor lowered and lowered. The second ribbon sensing is performed by detecting the second marker formed on the ink ribbon by reflecting on the recording paper, so the first ribbon sensing performed when the thermal head is raised and the ribbon sensor is raised, The irradiation light from the ribbon sensor can be reflected by a glossy reflecting plate at a distance.
Therefore, even if the distance from the ribbon sensor to the reflecting plate is long, ribbon sensing can be performed by brightly reflecting the irradiation light of the ribbon sensor with the reflecting plate, and high-accuracy first ribbon sensing can be performed. it can.
Further, in the second ribbon sensing performed when the ribbon sensor is lowered, the irradiation light of the ribbon sensor can be reflected by a white recording paper having a short distance.
For this reason, even when the recording member is white recording paper whose reflectance is inferior to that of the reflecting plate, the distance from the ribbon sensor is short, so that highly accurate second ribbon sensing can be performed.

Further, since the ribbon sensor is attached in the vicinity of the thermal head of the head guide that can come in contact with and separate from the platen roller in conjunction with the head up / down of the thermal head, the ribbon sensor can be easily moved up and down. .
In addition, after the first ribbon sensing, the recording paper is fed between the platen roller and the thermal head, and the thermal head is lowered to transfer the ink layer of the first color of the ink ribbon onto the recording paper. After the first color image is printed, the second ribbon sensing is performed continuously, and then the thermal head is headed up and the recording paper on which the first color image is printed is back-fed to the first color image. Since the image of the second color is overprinted on the image, the irradiation light of the ribbon sensor is reflected brightly on the recording paper at a short distance with the thermal head down after the first color image is printed. Thus, the second ribbon sensing can be performed, and the second ribbon sensing can be performed with higher accuracy.

In addition, the recording paper on which the first color image is printed has a blank portion on the rear end side. In the second ribbon sensing, the irradiation of the ribbon sensor is reflected at the blank portion to detect the second marker. Since the reflected light from the ribbon sensor at the time of the second ribbon sensing can be made to have the same brightness as the reflected light from the reflector at the time of the first ribbon sensing, Both ribbon sensing can be performed with high accuracy.

In addition, since the head guide when performing image printing on the recording paper is in the third position where the recording paper is pressed against the platen roller, the ribbon cassette can be exchanged at the first position. The recording paper can be fed and back-fed in the second position, and the recording paper being printed can be securely adhered to the platen roller in the third position.
When there is no recording paper between the platen roller and the head guide, the head guide is positioned at the first or second position to perform the first ribbon sensing. Since the first color image is printed on the recording paper at the third position and the head guide is positioned at the third position and the second ribbon sensing is performed thereafter, the first ribbon sensing is performed. The second ribbon sensing can be performed with the reflected light from the margin of the recording paper that is close to the ribbon sensor. It can be carried out.

Further, when continuously printing on a plurality of recording sheets, the first ribbon sensing when printing on the first sheet is performed when the head guide is positioned at the first position. Since the first ribbon sensing for subsequent printing is performed when the head guide is positioned at the second position, the thermal at the time of the first ribbon sensing is performed on the second and subsequent recording sheets. The head up / down time of the head can be shortened, and the printing speed can be improved.
In addition, the head guide is provided with a peeling roller on the downstream side of the ribbon sensor in the recording paper conveyance direction, and the ink ribbon that is in close contact with the recording paper during printing is peeled off by the peeling roller. The ink ribbon can be reliably peeled off and high-quality image printing can be performed on the recording paper.

Hereinafter, the printing method of the thermal transfer printer of the present invention will be described with reference to FIGS. 1 and 2 are cross-sectional views of the main part of the thermal transfer printer of the present invention, FIG. 3 is a plan view of an ink ribbon according to the present invention, and FIGS. 4 to 8 are schematic diagrams for explaining the printing method of the present invention. It is.
First, in the thermal transfer printer 1 according to the present invention, as shown in FIG. 1, a cylindrical platen roller 3 rotatably supported on a side plate 2a of a main body case 2 is disposed on the lower side.
Above the platen roller 3, a thermal head 4 comprising a long line head parallel to the axial direction of the platen roller 3 is disposed.
The thermal head 4 has a plurality of heating elements (not shown) aligned in the longitudinal direction on the side facing the platen roller 3, and is attached to the head support member 6 via the head mounting base 5.

The head support member 6 is formed with a head support portion 6a to which the head mounting base 5 is attached and an extension portion 6b extending from the head support portion 6a in a crank shape in the right direction in the figure. A heat sink portion 6c capable of radiating the heat of the head 4 is attached.
A support arm 6d is attached downward to the right end of the extending portion 6b in the figure, and the support arm 6d is rotatably supported by a support shaft 7 that bridges and supports the side plate of the main body case 2. That is, the thermal head 4 can be brought into and out of contact with the platen roller 3 (head up / down) by the head support member 6 rotating about the support shaft 7 as a fulcrum.

Further, the lower end side of the first coil spring 8 is supported on the head support portion 6 a of the head support member 6. Further, the upper end side of the first coil spring 8 is elastically biased to the pressure contact plate 9 a of the pressure contact member 9. The press contact member 9 has a press contact plate 9a formed in a long shape parallel to the longitudinal direction of the thermal head 4 on one end side, and both end portions of the press contact plate 9a are one end portions of a pair of rotating arms 9b. It is integrally formed on the side.
Further, the other end side of the rotating arm 9b is supported by the support shaft 7, and the press contact plate 9a moves up and down as the rotating arm 9b rotates about the support shaft 7 as a fulcrum.

The pressure contact member 9 is always elastically biased upward on the pressure contact plate 9a side by an elastic member (not shown). Further, the head support member 6 is elastically biased upward by being supported by an engaging portion 9c formed by cutting and raising a part of the rotating arm 9b.
Further, the press contact member 9 can move up and down by pressing the press contact plate 9a against the cam member 10 rotatably supported by the support shaft 10a supported by the side plate 2a.

Further, a head guide 11 separate from the head support member 6 is disposed so as to surround the head mounting base 5 to which the thermal head 4 is mounted. The head guide 11 has a cavity 11a formed therein, and the cavity 11a is open at the lower side by an opening 11b.
Further, a peeling roller 11c is rotatably supported at the lower left end portion of the head guide 11 shown in the drawing so that an ink ribbon 18 that is in close contact with a recording paper 17 (to be described later) can be peeled off during printing.

An optical ribbon sensor 12 is disposed on the left side of the opening 11b in the cavity 11a of the head guide 11 (on the downstream side of the thermal head 4 in the paper feeding direction of an arrow C of the recording paper 17 described later). The ribbon sensor 12 detects the ink layer of the ink ribbon 18 to be described later, and enables the ribbon cueing that can be aligned with the print start position. The head guide 11 is always elastically biased upward direction Do Re that is from the platen roller 3 by an elastic member (not shown), in the printing standby state of the thermal head 4 is the head-up state, in FIG. 1 As shown, the head guide 11 is also raised from the platen roller 3 by a predetermined amount.

Such a head guide 11 can be moved up and down independently by the same drive source that drives the cam member 10. When the thermal head 4 is headed down and printing is performed, the head guide 11 is lowered to the vicinity of the platen roller 3, and a plurality of heating elements of the thermal head 4 are positioned at the opening 11b and can be pressed against the platen roller 3. ing. Further, on the left side of the platen roller 3 in the figure, a paper feed roller 13 and a pressure roller 16 that presses against the paper feed roller 13 by a biasing force of the second coil spring 15 via a lever 14 are disposed.

Further, as shown in FIG. 1, when the cam member 10 is rotated substantially horizontally, the thermal head 4 rises to the maximum and the head guide 11 is greatly separated from the platen roller 3. It comes to become a position.
Further, when the cam member 10 is slightly rotated in the clockwise direction and the thermal head 4 is headed down by a predetermined amount, the separation distance of the head guide 11 from the platen roller 3 becomes a second position smaller than the first position. It has become.
Between the head guide 11 located at the second position and the platen roller 3, a recording paper 17 made of thick paper such as photographic paper capable of color printing is illustrated by a paper feed roller (not shown). Paper is fed in the direction of arrow C from the right side, and the front end portion 17 a is press-clamped between the paper feed roller 13 and the pressure roller 16.

The recording paper 17 held in pressure contact with the paper feed roller 13 and the pressure roller 16 can be conveyed in the direction of arrow C and back-fed in the direction of arrow D by the rotation of the paper feed roller 13. A recording sheet 17 fed between the platen roller 3 and the thermal head 4 and conveyed in the direction of arrow C has a front end portion 17a sandwiched between the sheet feeding roller 13 and the pressing roller 16 as a sheet sensor. When paper sensing is performed by detection (not shown), the rotation of the paper feed roller 13 is temporarily stopped. Further, as shown in FIGS. 7 and 8, blank portions 17d and 17d having a predetermined size on which no image is printed are formed on the recording paper 17 on which the image is printed, as shown in FIGS.

Further, an ink ribbon 18 is drawn around the upper side of the recording paper 17 between the head-up thermal head 4 and the platen roller 3.
The width of the ink ribbon 18 is slightly larger than the width of the recording paper 17. Further, as shown in FIG. 3, the ink ribbon 18 is formed on the lower surface side (the surface facing the recording paper 17), which is one surface of the ink ribbon 18, slightly longer than the printing range of the recording paper 17. Ink layers 18a of different colors coated with Y), cyan (C), and magenta (M) inks are formed.

  Then, the first marker 18b composed of two black streaks capable of detecting the first color Y ink layer 18a by the ribbon sensor 12 is the first color C ink layer 18a and the first color C ink layer 18a. It is formed in a transparent portion between the Y color ink layer 18a. The second marker 18c made of one black streak that can detect the ink layer 18a of M color and the ink layer 18a of C color by a ribbon sensor is provided with the ink layer 18a of Y color and the M color of the ink layer 18a. Are formed between the M ink layer 18a and the M ink layer 18a and the C ink layer 18a.

The first Y-color ink layer 18a is sensed by the first ribbon sensing in which the ribbon sensor 12 detects the first marker 18b, and the print start position of the Y-color ink layer 18a is thermal. The head 4 is aligned with the heating element 4a.
In addition, the M or C color ink layer 18a is sensed by the second ribbon sensing in which the ribbon sensor 12 detects the second marker 18c, and the M or C color ink layer 18a is printed. The starting position is aligned with the heating element 4 a of the thermal head 4.

In the ink ribbon 18, a transparent space portion 18d having a dimension E is formed between the first and second markers 18b and 18c and the ink layer 18a of each color.
The dimension E of the space 18 d is slightly smaller than the dimension from the heating element 4 a of the thermal head 4 to the ribbon sensor 12.
Therefore, even if the ribbon sensor 12 senses the first and second markers 18b and 18c slightly, the respective ink layers 18a are surely positioned at positions where the heating elements 4a of the thermal head 4 face each other. It is like that.
The both ends of the ink ribbon 18 are wound around a supply reel 19 and a take-up reel 20 and stored in a ribbon cassette 21.

As shown in FIG. 1, the ribbon cassette 21 is capable of winding a first ribbon storage portion 21a for storing a supply reel 19 in which an unused ink ribbon 18 is wound, and a used ink ribbon 18. A second ribbon storage portion 21b for storing the take-up reel 20 is formed.
And the 1st, 2nd ribbon accommodating parts 21a and 21b are connected by the connection wall 21c formed facing each other.

Further, the ribbon cassette 21 is formed with a drawer port 21d through which the ink ribbon 18 wound around the supply reel 19 can be pulled out on the connection wall 21c side of the first ribbon storage portion 21a, and the second ribbon storage portion 21b. A winding port 21e is formed on the connecting wall 21c side, and the ink ribbon 18 drawn out from the drawing port 21d can be taken up on the take-up reel 20.
Further, a guide insertion port 21f into which the head guide 11 that moves up and down can be inserted is formed in the connection wall 21c of the ribbon cassette 21.
Such a ribbon cassette 21 is formed inside the main body case 2 when the thermal head 4 is raised as shown in FIG. 1 and the head guide 11 is in the first position that is largely separated from the platen roller 3. The cassette mounting portion 22 is detachable.

  In addition, a paper guide 23 that can prevent the recording paper 17 being conveyed from being bent downward is disposed in the conveyance path of the recording paper 17 between the platen roller 3 and the paper feed roller 13. On the upper surface of the paper guide 23, for example, a reflecting plate 23a having a glossy mirror-finished surface to be a reflecting surface is fixed with an adhesive or the like. The reflection plate 23a may be formed by directly forming a glossy reflection surface on the upper surface of the paper guide 23 by metal plating or the like.

The operation of the thermal transfer printer 1 of the present invention having such a configuration will be described. First, in the initial state which is a print standby state, as shown in FIG. Is in the first position where the head guide 11 is largely separated from the platen roller 3.
When the head guide 11 is in the first position, the ribbon sensor 12 is largely separated from the reflecting plate 23a as shown in FIG.
When the head guide 11 is in the first position, the recording paper 17 is not fed between the platen roller 3 and the head guide 11 and is in a standby state.

When the print command is issued to the thermal transfer printer 1 when the head guide 11 is at the first position greatly separated from the platen roller 3, the ink ribbon 18 is wound on the take-up reel 20, and the ribbon sensor 12 is moved. First ribbon sensing is performed by detecting the first detection marker 18b. This first ribbon sensing, the printing start position of the first Y color ink layer 18a is aligned with the heating elements 4a of the thermal head 4.
The ribbon sensor 12 at the time of the first ribbon sensing is separated from the reflecting plate 23a. However, since the reflecting plate 23a has a glossy surface, the reflected light 12a from the ribbon sensor 12 is reflected brightly. be able to. Therefore, the ribbon sensor 12 can reliably detect the first marker 18b corresponding to the first Y-color ink layer 18a and perform highly accurate ribosensing.

Next, after the first ribbon sensing, the cam member 10 is slightly rotated clockwise to lower the thermal head 4 by a predetermined dimension and the head guide 11 as shown in FIG. The distance from the roller 3 is lowered to the second position closer to the first position.
Then, between the head guide 11 and the platen roller 3 located at the second position, the recording paper 17 is fed in the direction of arrow C from the right side of the figure, and the front end 17a of the recording paper 17 is fed to the paper feed roller 13. And the pressure roller 16 and the recording paper 17 is sensed by a paper sensor (not shown).

Thereafter, as shown in FIG. 2, when the cam member 10 is rotated to a substantially vertical shape and the press contact plate 9a is pushed downward, the lower surface of the lowered head guide 11 presses the recording paper 17 against the platen roller 3. 3, the recording paper 17 can be reliably brought into close contact with the outer peripheral surface of the platen roller 3. As a result, even if the recording paper 17 is warped, the head guide 11 in the third position can correct the warp.

At the same time, the pressure plate 9a which is pressed downward by the cam member 10, under the head support plate 6 is also pressed downward via the first coil spring 8 Gerare, the thermal head 4 was head down, recording paper with the ink ribbon 18 17 And the platen roller 3 are pressed against each other. At this time, the ink ribbon 18 is pressed against the recording paper 17 in a state where the first marker 18b is sensed by the first ribbon sensing performed by the ribbon sensor 12 when the head guide 11 is in the first position. Is done.

Then, the plurality of heating elements 4a of the thermal head 4 are selectively heated based on the printing information, and the paper feed roller 13 is rotated counterclockwise as shown in FIG. By transporting in the direction, as shown in FIG. 7, the ink of the first Y ink layer 18a of the ink ribbon 18 is transferred to the recording paper 17, and the Y image 17c is printed on the recording paper 17. Is done.
At this time, blank portions 17d and 17d on which the Y-color image 17c is not printed are formed on the front end portion 17a side and the rear end portion 17b side of the recording paper 17.

  Even after printing the Y color image 17c, when the thermal head 4 is lowered and the head guide 11 is positioned at the third position and the recording paper 17 is further conveyed in the direction of the arrow C, the ribbon sensor 12 Is reflected by the blank portion 17d, and the second marker 18c corresponding to the M ink layer 18a, which is the next color of the Y ink layer 18a, is detected, and the second ribbon sensing is performed. Is performed, and the conveyance of the recording paper 17 is temporarily interrupted.

Next, as shown in FIG. 8, the thermal head 4 is raised, and the head guide 11 is raised to the second position. Then, the paper feed roller 13 is reversed in the clockwise direction, the recording paper 17 is back-fed in the direction of arrow D, and the front end portion 17a of the recording paper 17 is sensed again.
Thereafter, the printing operation as shown in FIG. 6 is repeated to transfer the M color ink layer 18a onto the Y color image 17c, whereby the M color image is applied onto the Y color image 17c. Are overprinted.

And repeat the above printing operation, by overprinting the C color images on top of the color images of M, a color image is printed to the recording sheet 17 made of a desired color. When the recording paper 17 after printing is discharged and the recording paper 17 is no longer between the platen roller 3 and the thermal head 4, the thermal head 4 is used when images are continuously printed on the next recording paper 17. While raising the head, the head guide 11 is raised to the height of the second position.

Then, the first marker 18b corresponding to the Y ink layer 18a that is the first color to be printed on the next recording paper 17 is detected by the ribbon sensor 12, and the first ribbon sensing is performed.
Thereafter, the desired color image can be continuously printed on the next recording paper 17 by repeating the printing operation as described above.
That is, in the first ribbon sensing when continuously printing on a plurality of recording sheets 17, the head guide 11 is positioned at the first position away from the platen roller 3 for the first sheet. Sometimes, the second and subsequent sheets are performed when the head guide 11 is located at the second position that is closer than the first position.
Therefore, the head up / down movement amount of the thermal head 4 when printing on the second and subsequent recording sheets 17 can be reduced, and the printing speed can be increased.

In such a thermal transfer printer 1 of the present invention, since the ribbon sensor 12 is disposed in the vicinity of the downstream side of the thermal head 4, the dimension E of the space portion 18d of the ink ribbon 18 that is not used for printing can be reduced. The length from the ink layer 18a to the ink layer 18a can be shortened.
Therefore, it is possible to shorten the time for overlapping printing of the ink layers 18a and 18a of different colors, and to improve the printing speed.
Furthermore, the running cost of the ink ribbon 18 can be reduced. Therefore, the image printing cost per recording sheet 17 can be reduced.

It is principal part sectional drawing of the thermal transfer printer concerning this invention. It is principal part sectional drawing of the thermal transfer printer concerning this invention. It is a top view of the ink ribbon concerning this invention. It is the schematic explaining the printing method of the thermal transfer printer of this invention. It is the schematic explaining the printing method of the thermal transfer printer of this invention. It is the schematic explaining the printing method of the thermal transfer printer of this invention. It is the schematic explaining the printing method of the thermal transfer printer of this invention. It is the schematic explaining the printing method of the thermal transfer printer of this invention. It is principal part sectional drawing of the conventional thermal transfer printer. It is a top view of the conventional ink ribbon.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal transfer printer 2 Main body case 3 Platen roller 4 Thermal head 5 Head mounting base 6 Head support member 6a Head support part 6b Extension part 6d Support arm 7 Support shaft 8 First coil spring 9 Pressure contact member 9a Rotary arm 9b Pressure contact Plate 9c Engagement part 10 Cam member 11 Head guide 11a Cavity part 11b Opening part 11c Separation roller 12 Ribbon sensor 13 Paper feed roller 16 Pressure roller 17 Recording paper 17a Front end part 17b Rear end part 18 Ink ribbon 18a Ink layer 18b First marker 18c Second marker 18d Print image 19 Supply reel 20 Take-up reel 21 Ribbon cassette 23 Paper guide 23a Reflector

Claims (8)

A thermal head attached to a thermal head support member via a thermal head mounting base and disposed so as to be able to come into contact with and separate from the platen roller, an ink ribbon drawn between the thermal head and the platen roller, and the thermal head attachment An opening is formed on the lower side of the cavity surrounding the base so that the thermal head faces the platen roller and can be moved up and down independently, interlocking with the thermal head coming into contact with and separating from the platen roller A head guide capable of pressing and releasing the recording paper against the platen roller, and disposed in the vicinity of the downstream side of the thermal head in the recording paper transport direction when the head guide is printed. Ribbon sensing is enabled by detecting the reflected light. Nsensa, and to face disposed in the ribbon sensor across the conveyance path of the recording paper and the ink ribbon, the thermal transfer printer comprising a reflector which is capable reflected irradiation light of the ribbon sensor,
  A plurality of color ink layers used for color printing on each recording paper are formed in order, being longer than the printable range of the recording paper, shorter than the paper length, and printing the first color of the ink layers A first marker for aligning the print start position of the ink layer with the thermal head is formed at the front end of the ink layer provided for the ink layer, and the front end of each ink layer used for printing for the second and subsequent colors Using the ink ribbon on which the second marker for aligning the printing start position of each ink layer with the thermal head is formed, and transporting the recording paper forward and backward, thereby forming the ink layers of a plurality of colors. A printing method for printing a desired color image, in which a blank portion is formed at least at the rear end portion of the recording paper by overprinting by thermal transfer,
The first ribbon sensing for detecting the first marker is performed by raising the thermal head and raising the head guide and the ribbon sensor, and reflecting the irradiation light of the ribbon sensor by the reflecting plate,
  The second ribbon sensing for detecting the second marker is performed by lowering the thermal head, lowering the head guide and the ribbon sensor, and reflecting the irradiation light of the ribbon sensor at the blank portion. A printing method for a thermal transfer printer. After the first ribbon sensing, the recording paper is fed between the platen roller and the thermal head, the thermal head is lowered, the head guide and the ribbon sensor are lowered, and the ink ribbon is The first color ink layer is thermally transferred onto the recording sheet to print the first color image, and the second ribbon sensing is performed continuously with the thermal head, the head guide, and the ribbon sensor headed down. Thereafter, the thermal head is headed up, the head guide and the ribbon sensor are raised, and the recording paper on which the first color image has been printed is back-fed to the top of the first color image. 2. The thermal transfer printer according to claim 1, wherein the color image is overprinted. Printing method. The head guide has a first position that is largely separated from the platen roller when the thermal head is in a head-up state, and is smaller than the platen roller than the first position when the thermal head is in a head-up state. 3. A second position that is spaced apart and a third position that presses the recording paper against the platen roller when the thermal head is in a head-down state. A printing method for the thermal transfer printer described in 1. When there is no recording paper between the platen roller and the head guide, the head guide is positioned at the first position or the second position to perform the first ribbon sensing, and then the recording paper is fed. Paper, the thermal head is headed down, the head guide is positioned at the third position, and the first color image is printed on the recording paper. Thereafter, the head guide is moved to the third position. The thermal transfer printer printing method according to claim 3 , wherein the second ribbon sensing is performed while being positioned at a position. When continuously printing on a plurality of recording sheets, the first ribbon sensing for printing the first sheet is performed when the head guide is positioned at the first position. 5. The thermal transfer printer according to claim 3 , wherein the first ribbon sensing when printing on the second and subsequent sheets is performed when the head guide is located at the second position. 6. Printing method. In the head guide, a peeling roller is disposed on the downstream side of the ribbon sensor in the conveyance direction of the recording paper, and the ink ribbon that is in close contact with the recording paper during printing is peeled off by the peeling roller. printing methods of the thermal transfer printer according to any one of claims 1 to 5, characterized. A paper guide is disposed between the platen roller and a paper feed roller provided on the downstream side in the conveyance direction of the recording paper to prevent the recording paper from being bent downward. A printing method for a thermal transfer printer according to any one of claims 1 to 6. The reflective plate is disposed on the upper surface of the paper guide to prevent the recording paper from being bent downward, and when the recording paper is not fed, the reflective plate is disposed on the upper surface to prevent the recording paper from being bent. 8. The printing method of a thermal transfer printer according to claim 7, wherein ribbon sensing of 1 is performed.

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