JPS6129578A - Color thermal printer - Google Patents

Abstract

PURPOSE:To wind up ink carrier efficiently in a simple mechanism, by arranging a plurality of carriers of ink with different colors in layers and performing printing with a single thermal head on the same transfer printing line. CONSTITUTION:A printing signal actuates a stepping motor 51 to push up a cassette holder 46 and locate a ribbon cassette 35y in a printing position. A solenoid 33 is switched on to press a thermal head 23 against a platen 20 and mesh a relaying gear 59 with a winding gear 40 and an upper rotating gear 60 via a connecting arm 32. An ink ribbon 36Y is wound up by line transfer movement of a carriage 25 for printing. Then without delivery of paper, the carriage 25 is returned to printing starting position and a ribbon cassette 35M is moved to printing position for printing, followed by printing with a ribbon cassette 35C in the same manner as above.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention melts ink applied to an ink carrier by selectively generating heat from a plurality of heating elements disposed on a thermal head, thereby melting the ink applied to the ink carrier, The present invention relates to a thermal printer that transfers and records images onto a recording medium, and more particularly relates to a thermal transfer type color thermal printer that records a color image by sequentially superimposing ink images of different colors on a recording medium using a plurality of ink carriers. .

``Prior Art'' In recent years, various color thermal printers have been proposed in response to the demand for multicolor recording information, but their configurations can be roughly divided into a single ink carrier on which multiple ink layers of different colors are formed. (ribbon) with a negative thermal head installed on the back side, and color printing is performed by scanning the head multiple times on the same character line, or printing with multiple different color ink carriers and the ink carrier. There is also a system which has a corresponding number of thermal heads and arranges them in parallel in the scanning direction on a carriage so that color printing can be performed in one carriage scan.

To briefly explain these configurations, Fig. 5 shows the configuration of the former color printer, in which l indicates a plurality of ink layers of different colors IY, IM, and 1G consisting of yellow, magenta, and cyan formed in parallel to the longitudinal direction. The ribbon 1 is a band-shaped ink ribbon, and the ribbon 1 is stretched over almost the entire width of the recording paper 5 along the scanning direction of the head 2. Reference numeral 2 denotes a serial type thermal head 2 disposed on the back side of the ink ribbon 1, and is attached to a carriage 4 that reciprocates in the head scanning direction along a guide shaft 3. (Unexamined Japanese Patent Publication No. 58-84884 5B
-131074) In such a device, each time the thermal head scans the same character line,
The ink layer IY...
After one line of color image is recorded by sequentially feeding one ink image of each color onto the recording paper 5 by feeding it by the width of the recording paper 5, the ink ribbon l is wound up by the width of the recording paper 5 to record the next ink image. It is possible to record color images of rows.

On the other hand, FIG. 6 shows the configuration of the latter color printer.
la... are thermal heads 13a, which are arranged at equal intervals along the head scanning direction on the front side of the carriage 12;
. . . are monochrome ink ribbons coated with inks of three primary colors, and are passed from a ribbon cassette (not shown) placed on the carriage 12 via pinch rollers 14 and 15 to the corresponding heads lla . . . on the front side. is being drawn out.

(Japanese Unexamined Patent Publications No. 58-55258 and No. 58-102, in such devices, while moving the carriage 12 in the scanning direction, one or more selected heads lla... carry out a printing operation, thereby scanning - times. The three primary colors are superimposed, and a predetermined color image is recorded on the recording paper 5.

"Problems to be Solved by the Invention" However, all of these conventional techniques have the following drawbacks.

That is, in the former case, since the laminated ink layers IY... are formed on a single ink ribbon 1, -color or two
Even if only the color ink layer IY is used and there is an unused ink layer 1G, it is necessary to wind up the ink ribbon l for the width of the recording paper every time a line is changed, and the ink ribbon l
Because the transfer is performed while the ribbon is stretched across almost the maximum width of the recording paper, even when printing in three colors, the ink ribbon is wound up with a considerable amount of ink layer remaining in the unused portion, and the ink ribbon is rolled up. The amount of waste of ribbon 1 becomes extremely large.

Further, the ink ribbon 1 has an ink layer IY... in the width direction.
Since the ink ribbon 1 is formed by laminating them, the width of the ink ribbon 1 is inevitably wide and the ribbon 1 is easily twisted and wrinkled.
Since the transfer operation is repeated a maximum of 375 to 4 times over the same area, there is a risk of cutting the ink 1 nopon 1 and the stability of printing quality is problematic.

On the other hand, when using the latter color printer, the above-mentioned drawbacks are solved, but conversely, the ink ribbon 13a...corresponding number of thermal heads lla... and the ribbon cassette carriage are Since they must be arranged horizontally in a row, the device inevitably becomes larger, and furthermore, the head
The number of drive systems for la... and the winding drive systems for ink ribbon 13a... are also individually corresponding to each other. This led to a large increase in costs and became a major bottleneck in cost reduction.

In view of the drawbacks of the prior art, the technical problem of the present invention is to
It is an object of the present invention to provide a color thermal printer which is small in size, allows efficient winding of an ink carrier, and has a single mechanical cylinder.

"Means for Solving the Problems" The present invention, as a technical means for achieving such technical problems,
For example, in a serial type color thermal printer, ribbon cassettes containing ink ribbons of different colors are stacked and arranged on a carriage via a cassette holder, and the cassette holder is moved in the paper feeding direction perpendicular to the head scanning direction. Each time a single thermal head located on the back side of the corresponding ink ribbon scans the same character line (transfer line), the ribbon cassette is sequentially moved to the same character line by moving the cassette holder. A color thermal printer configured to record a color image by sequentially superimposing ink images on a recording medium is proposed.

Of course, the present invention can be applied not only to serial type color thermal printers but also to rice cake type color thermal printers. In this case, there is no need to perform he/at scan, so
There is no need for a carriage, and the ink carriers stacked on the cassette holding table are sequentially positioned on the same character line, and the ink images are sequentially superimposed using a line-type thermal head.

"Operation" According to this technical means, since a plurality of ink carriers of different colors are arranged in a stacked manner in the paper feeding direction, each ink carrier can be wound up independently. There is no need to wind up an unused ink layer, and the ink carrier can be used efficiently.

Further, since the ink carrier does not need to be formed by laminating a plurality of ink layers in the width direction, it can be formed narrowly,
The ink carrier does not twist or wrinkle, and even if the transfer operation is repeated multiple times, there is no risk of the ink carrier being cut or the stability of print quality is reduced.

In addition, in a serial type color thermal printer, for example, by arranging ink carriers in a stacked manner on a carriage, the carriage can be made the same size as a monochrome thermal printer, and the head scanning length can be reduced. Since the length can also be shortened, the entire device can be significantly downsized.

Further, since the ink carriers are arranged in layers, the ink carriers can be wound up by a negative drive system with a simple switching means, and the mechanism can be simplified and the number of parts can be reduced. - Furthermore, since the ink carrier is arranged in layers, the switching can naturally be carried out quickly.

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described by way of example with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the components described in this example are not intended to limit the scope of this invention, but are merely illustrative examples. It's nothing more than that.

1 to 4 each show the configuration of a color thermal printer according to an embodiment of the present invention.

20 is a platen rotatably supported by the printer housing;
A recording paper guide 21 and a pinch roller 22 are arranged around the recording paper guide 21, and each time one line of color information is recorded on the recording paper 24 guided around the circumference of the platen 20 by multiple scans of the thermal head 23 described later, the recording paper guide 21 and the pinch roller 22 are arranged. The paper 24 is intermittently fed one line at a time.

Reference numeral 25 denotes a substantially rectangular flat carriage, which is slidably supported on a guide shaft 27 via a pair of arm portions 2B fixed on both sides of its front lower surface, and a drive belt (not shown) is connected to the carriage 25. , is configured to reciprocate in parallel with the axis of the platen 20. Further, a running rail 28 having an angular cross section is disposed below the rear end of the carriage 25 in parallel with the guide shaft 27, and is configured to be able to run on the running rail 28 by running rollers 29 attached to the rear end side of the carriage 25. death,
The detailed structure of the carriage 25, which prevents the carriage 25 from swinging back and forth during reciprocation, will be described later. still,
The running wool 28 is mounted on a rack 30 at the side end on the side of the platen 20.
is engraved.

On the other hand, a head holding member 31 is rotatably supported on a part of a guide shaft '27 sandwiched between both arms 26 of the carriage 25.

The head holding member 31 includes a base portion 31a that is rotatably supported by the guide shaft 27, and a flat head holding portion 31b extending perpendicularly from the base portion 31a to face the surface of the platen 20.

The base portion 31a has a lower end hanging down like a tongue, and a connecting arm 32 is rotatably connected to the terminal end thereof. On the other hand, the head holding section 31b has a thermal head 23 on the platen 20 side.
At the same time, a solenoid 33 fixed to the carriage 25 is connected to the back side of the solenoid 33, and the solenoid 33 is reciprocated by a print signal from a control circuit (not shown), so that the thermal head 23 approaches and separates from the surface of the platen 20. Configure as possible. Also, a coil spring 31c is installed on the back side of the head holding part 31b.
The thermal head 23 is pressed against the surface of the platen 20 with a predetermined pressure.

It is configured so that

35! ... are ribbon cassettes arranged in a stacked manner on the carriage 25, each containing cyan, magenta, yellow single color ink ribbons 38y...
Since they all have the same configuration, only the configuration of the ribbon cassette 35y will be described. A reel 38 and a supply reel 38 are rotatably housed. A ribbon take-up gear 40 is coaxially fixed on the top surface of the take-up reel, and a part of the circumferential surface of the gear 40 is exposed to the outside through an opening 41 formed at the rear end of the cassette. There is. As a result, the ink ribbon 36y is pulled out from the supply reel 38 by the rotation of the take-up gear 40, guided to the head 23 surface of the head holding member 31 from the front side of the recess 37 while changing direction by the roller shaft 42, and then wound. It is configured to be wound onto a take-up reel 38.

In addition, the ribbon force set) 35y is the supply reel 38.
Three through-holes 43a are formed in each of the side corners and the front corner of the take-up reel 38, and can be fitted into three wooden shaft columns 44a standing upright on the carriage 25. At the same time, the central part of the end surface on the side of the supply reel 39 is opened to form an opening window 45 for detecting the amount of winding of the ink ribbon 38y.

Next, the detailed configuration of the carriage 25 will be explained.

The carriage 25 has a ribbon cassette 35y as described above.
Three pieces of wood 44a are vertically erected on the upper surface of the platen 20 side corresponding to the through-holes, and a cassette holding stand is attached via a coil spring 34 that applies an upward elastic force to the 44a. 4B, and each cyan, magenta, and yellow single color ink ribbon 3f3y is placed on the cassette holding table 48, respectively.
After sequentially stacking and arranging the ribbon cassettes 35y... storing the ribbon cassettes 35y...
- is removably locked by a locking spring 47 that is fixed to the side end of the carriage 25 and extends upward along the side surface of the cassette.

The locking spring 47 is disposed at a position corresponding to the opening window 45 of the cassette, and the ink ribbon 36y...
A photo sensor 48 is arranged to detect the end of the ink ribbon 38y, and when the ink ribbon 38y has finished winding, a detection signal is input to the control circuit to automatically interrupt the printing operation and send a signal to the user requesting cassette replacement. It is configured to be released.

Returning to its original state, the cassette holding base 46 has a notch at its approximately center portion, and the notch 4Ela is bent downward' at a right angle, so that the drive arm 50 can be rotated into the notch 48a. It is connected to. The drive arm 50 extends below the carriage 25 through an opening formed in the carriage 25, and its terminal end is rotatably connected to an eccentric pin 52 attached to the output shaft of a stepping motor 51. The stepping motor 51 is fixedly installed on the upper surface of the carriage 25.
The rotation of the motor 51 causes the eccentric pin 52 to rotate at a predetermined radius of rotation.

The rotation radius of the eccentric bin 52 is the same as that of the ribbon cassette 35y.
The length is set to be the same as the thickness of .

The structure will be explained in more detail with reference to FIGS. 4A to 4C. When the eccentric bin 52 is located at the lower end, the upper ribbons stacked and placed on the cassette holding table 48,
35y is the predetermined printing position, that is, the ribbon cassette 35y
The ink ribbon 36y pulled out further is configured to be located on the thermal head 23 surface of the head holding member 31 (No.-ArI!J) L, hereinafter, the eccentric bottle 52 is connected to the motor 51
When located on the horizontal axis, the middle ribbon cassette 3
5m (Fig. 4B), and when the eccentric pin 52 is located at the upper end, the lower ribbon cassette 35c (Fig. 4C)
They are configured to be pushed up to the respective positions. .

Next, the means for winding up the ribbon cassette 35y will be explained.

Reference numeral 53 denotes a substantially oval-shaped rotating arm, which includes a horizontal portion 53a located on the upper surface of the carriage 25 at the rear of the cassette mounting device, and a vertical portion extending toward the carriage 25F from a rectangular opening 54 formed on the gear ridge 25. A shaft hole is bored at a substantially central position of the horizontal portion 53a, the shaft hole is fixed on the carriage 25, and is rotatably supported by the protruding shaft 55; A lever spring 58ft is engaged with the horizontal portion 53a to apply an elastic force clockwise. A relay gear 58 is rotatably attached to the forward side of the horizontal portion 53a via a vertical shaft 57, and the relay gear 59 is connected to a corresponding ribbon cassette.
It is configured to mesh with the winding gear 40 of. On the other hand, the other end of a connecting arm 32 connected to the lower end of the head holding member 31 is rotatably connected to the terminal end of the vertical portion 53b.
The rotating arm 53 rotates via the vertical shaft 53, and the vertical shaft 57 holding the relay gear 58 rotates following the rotation. As a result, the platen 20 of the thermal head 23
In conjunction with the movement toward and away from the surface, the relay gear 58 transmits the rotation of the upper rotary gear 60 to the take-up gear 4'0 and releases the rotation, that is, the ink ribbon 3B! ...The winding can be switched.

On the other hand, the upper rotating gear 60 is attached to a rotating shaft 62 disposed on the side of the relay gear 58 via a friction mechanism B1. The rotating shaft 62 is rotatably supported perpendicularly to the carriage 25, and its lower end passes through the carriage 25 to the position where the traveling rail 28 is disposed below it. A lower rotating gear 83 that meshes with a rack 30 carved in the running rail 28 is fixedly attached to the lower end of the rotating shaft 62.
The upper rotating gear 60 is configured to rotate via the upper rotary gear 62.

Next, the effects of this embodiment will be explained.

First, when the machine is stopped, the solenoid 33 is in the OFF state, so the head holding member 31 is rotated in the direction opposite to the platen 20, and the thermal head 23 and the platen 20 are separated. - On the other hand, since the connecting arm 32 connected to the lower end of the base 31a of the head holding member 31 is also pulled toward the platen 20, the relay gear attached to the single rotation shaft 62 on the forward side of the rotating arm 53 59 is also spaced apart from the take-up gear 40 and the upper rotating gear 60. (See FIG. 1) When the power switch is turned on, the carriage 25 moves to the printing start position via the drive belt, and as a result of this movement, the lower rotating gear 83 meshing with the rack 30 of the traveling rail 28 is moved. rotates, and the upper rotating gear 60 also rotates via the rotating shaft 82, but since the rotating gear 60 and the relay gear 58 are separated from each other, the take-up gear 40 does not rotate, and therefore the ink ribbon 38. The carriage 25 can be moved without being wound up.

Next, when the print start signal is issued, the stepping motor 51 rotates to push up the cassette holding base 46 and position the selected ribbon cassette 35y in the upper, middle, or lower row at the printing position. At the same time, the solenoid 33 is turned on, and the platen 20 of the thermal head 23
At the same time as pressing against the surface, the connecting arm 32 is pulled toward the side opposite to the platen 2o, and the relay gear 59 attached to the rotating shaft 62 on the tip side of the rotating arm 53 is engaged with the 1st take-up gear 4o and the upper rotating gear 6o. Let me do it. As the carriage 25 moves in the feed direction, the lower rotary gear 83 meshing with the rack 3o of the traveling rail 28 rotates, and the upper rotary gear 8
o-Relay gear 59-Take-up reel 3 via take-up gear 40
8 rotates, and as a result, along with the movement of the carriage 25,
The ink ribbon 3B is wound up while selectively heating the heating elements of the thermal head 23, and the first ink ribbon 38y is scanned for printing.

(See FIG. 3) Furthermore, since a friction mechanism θI is interposed between the upper rotating gear 6o and the lower rotating gear 63, the ink ribbon 3
Ribbon 36y resulting from change in winding diameter (amount) of 8y
Prevents over-winding.

Next, without feeding the paper, the carriage 25 is returned to the printing start position on the same line (character line), and the second selected lipon cassette 3511 is positioned at the printing position by rotating the stepping motor 51ff. The second ink and ribbon 38m are transferred by scanning in the same manner as described above, and then the third ink ribbon 38c is transferred.
By performing the transfer operation, the three primary colors are superimposed, and predetermined color information is recorded on the recording paper 24.

- After recording the color information for the gender, feed the paper one page.

The color information of the next line is recorded by the same operation, and this process is repeated thereafter.

According to this embodiment, in addition to the effects of the present invention, since the winding of the ink ribbon is configured in conjunction with the approach and separation of the thermal head, the ribbon winding can be interrupted at the same time as the separation of the head, resulting in further efficiency. The eggplant is rolled up and its reliability is ensured.

Further, since the ribbon winding is performed in conjunction with the movement of the carriage without using an independent drive system, the apparatus can be made smaller and have fewer parts, leading to cost reduction.

In the above embodiment, the configuration of a color printer using ink ribbons of three primary colors has been described, but a color printer with four primary colors including black can also be configured in the same manner.

In this case, the length of the rotation radius X (r3/2) of the eccentric bin 52 is set to the length of the ribbon cassette 35! If the length is set to be the same as the thickness of the ribbon cassette 35!, and the cassette holding base 46 is pushed up to a predetermined position by rotating the stepping motor 51 in 30 degree increments, the corresponding ribbon cassette 35! ...
can always be positioned on the same character line.

"Effects of the Invention" As described above, according to the present invention, a plurality of ink carriers of different colors are arranged in a layered manner, and a printing operation is sequentially performed on the same transfer line by a single thermal heater. Therefore, efficient winding of the ink carrier, stabilization of printing quality, miniaturization of the device, etc. are achieved, and the winding mechanism of the ink carrier is not provided independently, and the It is also possible to drive the integrated winding mechanism in conjunction with the head contact/separation mechanism, which has an outstanding effect of simplifying the mechanism.

[Brief explanation of the drawing]

1 to 4 each show the configuration of a color thermal printer according to an embodiment of the present invention, and FIG. 1° is a perspective view;
Fig. 2 is a side view, Fig. 3 is a partially cutaway plan view clearly showing the main parts of the present invention, and Figs. 4A to 40 show changes in the position of the ribbon cassette. Figure 11I5#A

Claims (1)

[Claims] A plurality of ink carriers arranged in a stacked manner in a paper feeding direction, a single thermal head that transfers an ink image of the ink carriers onto a recording medium, and a moving means that moves the ink carriers on the same transfer line. and is configured to perform a transfer operation by a thermal head each time the selected ink carrier is positioned on the same transfer line, and record a color image while sequentially overlapping the ink images on the recording medium. Color thermal printer with special features.