JPH04189583A - Color ink ribbon cassette and cassette drive control mechanism - Google Patents

Abstract

PURPOSE:To obtain a proper ink ribbon life and reduce the cost by a method wherein color ink ribbons of different colors are contained in a plurality of sub-cassettes, the travel of a drive roller and a pinch roller is controlled for every sub-cassette, and the sub-cassettes can be replaced per unit. CONSTITUTION:Four sub-cassettes 1-1, 2, 3, 4 are stacked. The sub-cassettes contain ink ribbons of different colors and each have a drive roller, a rotating lever, a pinch roller, and a rotating lever spring. In each of four drive rollers 5-1, 2, 3, 4, upper and lower shaft parts 5a, 5b are rotatably supported by bearing parts of the body and the cover of the sub-cassette. A roller drive shaft 16 is installed through the four drive rollers. The cross section of the roller drive shaft 16 is of a cross form, and through holes 5a of the drive rollers 5-1, 2, 3, 4 are also of a cross form. In this manner, the drive shaft 16 and the drive rollers are fitted in shape, and the rollers are integrally rotated without a backlash between the roller drive shaft 16 and the holes 5a of the drive rollers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ink ribbon cassette for a serial printer that performs color printing and a drive device thereof.

An object of the present invention is to improve color printing quality, reduce ink ribbon running costs, and reduce ink ribbon drive load.

[Conventional technology]

Conventional color ink ribbon cassettes are approximately 1 inch (2
A single cassette contains an integrated ribbon made by uniformly painting cloth with a width of 5.4 mm in four different colors, and the width of the ink ribbon is about 2 times the width of a regular black ink ribbon (13 mm).
There are twice as many.

[Problem to be solved by the invention]

Color ink ribbons have different ribbon lifespans depending on the color. As a typical example, the ink ribbon life for black is 1 million characters, for yellow 500,000 characters, for cyan 700,000 characters, and for magenta 70 characters.
It's a million characters. In other examples of ink ribbons, the lifespan ratios have similar relationships. Under general printing conditions, black is used most frequently, and even in the above-mentioned typical example, black print density decreases fastest, and black determines the life of the ink ribbon. Also, among yellow, cyan, and magenta, yellow wears out the fastest, and yellow determines the lifespan. As described above, the lifespan of each color of the ink ribbon is uneven, so that there are disadvantages such as deterioration of print quality when used beyond the lifespan and increased running cost to adjust the usage limit to the shortest lifespan.

In addition, wide ink ribbons have large driving resistance, require a high-torque drive motor, and consume a lot of power, resulting in high costs.

[Means and actions to solve the problem]

The color ink ribbon cassette of conventional serial dot printers had a one-piece structure, but the cassette is divided into sub-cassettes for each ink ribbon color and stacked, making it possible to replace only the ink ribbon that has reached the end of its life in sub-cassette units. The configuration is such that only the desired color ink ribbon is driven and fed. Specifically, a plurality of sub-cassettes each contain monochromatic color ink ribbons coated with different colors, and each sub-cassette has a drive roller that drives the ink ribbon, and a movable roller that contacts or separates from the drive roller. By doing so, a pinch roller that pinches and releases the ink ribbon from the drive roller and a control means that controls the movement of the pinch roller are provided, making it possible to replace the color ink ribbon in sub-cassette units. .

The cassette drive control device vertically displaces the stacked ink ribbon cassettes, aligns only the ink ribbon of the selected sub-cassette with the print head position, and drives the ink ribbon between the drive roller and pinch roller to perform printing. In other sub-cassettes, the drive roller and pinch roller are separated and the ink ribbon is not fed.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

In the first country, 1 is an ink ribbon sub-cassette, and the ink ribbon 4 is housed inside the sub-cassette body 2 and the sub-cassette lid 6. In the figure, a part of the lid is cut away to show the inside. It is. 5 is a drive roller, which rotates while sandwiching the ink ribbon 4 between it and a pinch roller 7;
Drive the ink ribbon 4. The pinch roller 7 is rotatably supported by one end 6d of the rotary lever 6. X-X
A partial cross-section taken along the line is shown in Figure 1 CB)'c, but the upper shaft 6a and lower shaft 6b of the rotating lever 6 are connected to each other. ing. The rotating lever 6 is biased counterclockwise by a rotating lever spring 8, and a protrusion 6c protrudes from a window 2a provided on the side surface of the sub-cassette body 2, and this portion is connected to a rotating lever cam 14, which will be described later. comes into contact with.

FIG. 2 is a front view, and the cassette has a structure in which four sub-cassettes 1-1.2.3.4 are stacked and integrated by a connecting member. Each sub-cassette accommodates ink ribbons of different colors, and each sub-cassette has a driving roller 5, a rotating lever 6, a pinch roller 7,
A rotation lever spring 8 is provided. As shown in the figure, sub-cassette 1-1 has a height approximately twice that of the other three sub-cassettes. This is because sub-cassette 1-1 is for black ink ribbon, and the other sub-cassettes are for yellow, cyan, magenta, etc., and since black ink ribbon wears out particularly rapidly, the width of black ink ribbon is used for other colors. The ink ribbon is doubled and uses two printing tracks, one above the other, in order to increase its lifespan. In the case of this embodiment, the connecting members that integrate the four sub-cassettes are the four elastic arms 9 provided on the sub-cassettes 1-4, which hold the other three sub-cassettes in a stacked manner. By locking the sub-cassette 1-1 with the hook portion 9a at the upper end of the elastic arm, the four sub-cassettes are integrated. Therefore, if any of the ink ribbons becomes worn out, only that sub-cassette can be easily removed and replaced with a new one. Also, sub cassette 1-4
has shafts 10a and iob on the right side, and as seen in the first report, these shafts are supported by the carriage 11 of the printer body so that they can be easily attached to and detached from and rotated freely. A cassette swing cam 16 is fixed to the step motor shaft 12, has five indexing heights, and is a control means that comes into contact with the lower surface of the sub-cassette 1-4 to determine the inclination angle of the sub-cassette. When the cassette swing cam 13 rotates, the entire four integrated sub-cassettes swing around the axes 10a, b' according to the contour shape of the cassette swing cam 16, taking five tilted positions. Although the cassette swings primarily due to gravity, the operating speed can be increased by suspending a spring between the cassette and the printer carriage to pull the cassette against the cassette swing cam 13.

A rotating lever cam 14 is fixed to the step motor shaft 12 together with a cassette swinging cam 16, and this is a control means for operating the rotating lever 6. The rotary lever cam 14 is provided with five control recesses 15a, a, b, c, and d in correspondence to the fact that the integrated cassette assumes five tilted positions by the cassette swing cam 16. In the state shown in FIG. 2, the sub-cassette 1-2 is selected, and the protrusion 6C-2 of the rotating member of this sub-cassette is engaged with the control recess 15b, but the other three The control lever protrusions 6C-1, 3, and 4 of the sub-cassette are in contact with the flat surface of the rotating lever cam 14.

Partial cross-sections of each sub-cassette are shown in the third edition.

The four drive rollers 5-1.2.3.4 each have upper and lower shaft portions 5a, 5b connected to the main body 2-1.2. of each sub-cassette.
3.4 and the bearings of the lid 6-1.2.3.4 are rotatably supported in the section, and a roller drive shaft 16 passes through the four drive rollers. The roller drive shaft 16 has upper and lower shaft portions 16
The bearings of the lid 6-1 of the sub-cassette 1-1 and the main body 2-4 of the sub-cassette 1-4 are rotatably supported at +1.16b, and the drive shaft gear 17 is fixed to the lower end 16C by a screw 18. ing. The drive shaft gear 17 meshes with the drive gear 21 via an intermediate wheel 19. A compression spring 20 is built into the intermediate wheel 19, and when the cassette is attached to the carriage of a printer, if the drive shaft gear 17 and the intermediate wheel 19 do not mesh, the intermediate wheel 19 will move downward. It is designed so that it does not escape and interfere with installation. Figure 3 (B)
As shown in the figure, the cross section of the roller drive shaft 16 is cross-shaped, and each drive roller 5-1.
Since the roller drive shaft 16 and the four drive rollers 5-1.2.3.4 are also shaped like a cross, they are connected in shape and rotate as one. Roller drive shaft 16 and drive roller hole 5
A sufficient gap is provided between a to absorb errors caused by mis-passing, and to allow rotation without creaking.

In FIG. 4, 22 is a step motor, which is not shown but is fixed to the carriage of the printer. In order to clarify the rotation reference position and rotation angle of the step motor 22 and to ensure the selection of the sub-cassette, a signal plate 26 is fixed to the step motor shaft, and the signal plate 26 and the detector 24 cause the cassette to swing. The rotational positions of the cam 13 and the rotating lever cam 140 are detected.

Next, the operation will be explained.

The step motor rotates in response to a command signal from the printer main body, and the cassette swing cam 16 rotates to tilt the integrated cassette in five stages. For example, in the state shown in FIG. 2, sub cassette 1-2 is selected. The ink ribbon exposed at the left end of the cassette faces a print head (not shown). At this time, sub cassette 1-
20 The protrusion 6C-2 of the rotating lever is the rotating lever cam 14.
Since the rotary lever of this sub-cassette falls into the control recess 15b of the
The ink ribbon 4 is rotated counterclockwise by zero force, and the pinch roller 7 and drive roller 5 pinch the ink ribbon 4. As a result, the drive roller 5 rotates as printing is performed, and the ink ribbon 4 is fed. Other three sub-cassettes) 1-1.
In 3.4, the protrusions 6C-1, 3, and 4 of the rotating lever do not face the control recess of the rotating lever cam 14, but contact the flat surface of the cam, so the rotating lever does not touch the shaft 6a. The pinch roller 7 is located at a position slightly rotated clockwise from the center and is away from the drive roller 5, and the ink ribbon 4 is not caught between the two rollers and is not fed even when the drive roller rotates. . In this way, the ink ribbon of a particular sub-cassette comes to the print head position, is used for printing, and is fed by the rotation of the drive roller. On the other hand, in sub-cassettes other than the selected one, the ink ribbon is out of the print head position and is not fed even if the drive roller rotates. Control recesses 15b, c of rotating lever cam 14
, d respectively correspond to the sub-cassette 1-2.3.4, but for the sub-cassette 1-1, two control recesses 1
5a and a are provided. This is because, as described above, the black ink ribbon of the sub-cassette 1-1 is wide, and the cassette assumes two inclined positions as the cams 1lffi 13a and 13b of the swinging cam 16 come into contact with the cassette.
This is because the upper half or the lower half of the width of the ink ribbon faces the print head, and control recesses are provided for the two positions of the rotating lever thrusting part 6cm1, respectively.

FIG. 5 shows another embodiment of the invention. Sub cassette 1-
1, 2.3.4, the bottom plate and the lid 6-1.2.3.4 of the main body 2-112.3.4 are made thicker at the rear, and as they approach the tip, they are thickened as far as the strength allows and a plurality of The cassette is thin enough to avoid interference with the color ink ribbon, and as a result, the cassette has a tapered outer shape. The reason why the rear part is made thicker is to ensure support for the rotation lever and drive roller, and the reason why the tip is made thinner is to reduce the distance between the centers of the ink ribbon width and to reduce the amount of oscillation of the cassette when selecting the ink ribbon. This is to minimize.

Although not shown in the figure, a detection switch is provided on the printer's carriage, and the laminated cassette of the present application is provided with a protrusion that contacts the detection switch, while a single-configuration cassette is not provided with a protrusion, which allows the printer main body to A structure that automatically determines the type of installed cassette is used as appropriate.

〔Effect of the invention〕

According to the present invention, since a plurality of monochromatic color ink ribbons can be replaced in units of sub-cassettes, the life of the ink ribbon can be optimized, and running costs can be reduced and print quality improved.

In addition, since the cassette drive control device drives only the selected ink ribbon, the driving load on the ink ribbon is reduced, reducing the cost of the motor, and when using a one-time film color ribbon with excellent printing quality. It can also be used without waste.

Furthermore, by loosely engaging the cassette drive shaft and each drive roller, errors in misalignment of the shafts can be absorbed and the driving force of the ink ribbon can be minimized.

Furthermore, each sub-cassette lid and sub-cassette body has a bottom surface that is thicker at the rear and thinner at the tip, which ensures reliable support for mechanical parts such as drive rollers and rotating levers. The amount of oscillation of the cassette when changing colors can be minimized, making it possible to speed up ink ribbon switching.

[Brief explanation of drawings]

Figure 1 is an embodiment of the present invention, where the prisoner is a front view, 03) is a partial sectional view of the prisoner taken along the line X-X, Figure 2 is a front view of the embodiment, and the third country is a laminated layer of the embodiment. Partial sectional view of sub-cassette,
The third view is a diagram showing the shape connection of the roller drive shaft and the drive roller, and FIG. 4 is a front view of the area around the step motor of the embodiment. FIG. 5 is a partial cross-sectional view showing a stacked form of sub-cassettes according to another embodiment of the present invention. 1...Sub cassette, 4...Ink ribbon, 5...Drive roller, 6...Rotating lever, 7...Pinch roller -1 11...Carriage, 13...Cassette swing cam, 14...Rotating lever cam, 16...Roller drive shaft, 22... ...Step motor. Figure 3 (A) Go to 1, 1 1g Figure 4 r"-"-1"'-"] Fifth

Claims (6)

[Claims] (1) Between the monochromatic ink ribbon, a drive roller having a hole that is geometrically connected to the roller drive shaft of the cassette drive control mechanism, and the drive roller that approaches or moves away from the drive roller under the control of the cassette drive control mechanism. A configuration in which a pinch roller for pinching or releasing the ink ribbon is housed in a sub-cassette, and a plurality of sub-cassettes with different colors of ink ribbons are stacked and connected by a connecting member so that any sub-cassette can be replaced. color ink ribbon cassette. (2) In the color ink ribbon cassette according to claim 1, by making the gap between the roller drive shaft of the cassette drive control mechanism and the hole of the drive roller loose, the roller drive shaft and the drive roller are engaged without creaking. A color ink ribbon cassette that rotates in unison. (3) The color ink ribbon cassette according to claim 1, wherein the width of the black ink ribbon is at least about twice the width of the ink ribbon of a color other than black. (4) The color ink ribbon cassette according to claim 1, wherein the height of the sub-cassette has a taper that decreases as it approaches the print head side. (5) The color ink ribbon cassette according to claim 1, wherein the connecting member is provided integrally with the sub-cassette. (6) A roller drive shaft that passes through and connects to a plurality of drive rollers of a laminated color ink ribbon cassette to transmit rotation; A cassette drive control mechanism comprising: a control means for adjusting the position of the sub-cassette; and a control means for bringing the pinch roller of the selected sub-cassette into contact with the drive roller while pinching the ink ribbon.