KR970005578B1 - Printer having ribbon shift mechanism - Google Patents

Abstract

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Description

Printer and web handling device with ribbon moving mechanism

1 is a perspective view of a printer in a preferred embodiment.

2 is a perspective view showing a part of the inside of the printer of FIG.

3 is an exploded perspective view of the assembly of FIG.

4 is an exploded perspective view of the assembly of FIG.

* Explanation of symbols for main parts of the drawings

10: printer 12: printhead

13 carriage 14 ribbon stage or moving mechanism

15 gear shaft 16: rack

18,23: bevel gear 19: stepping motor

20: printer ribbon 25, 31: slot

32: gear

The present invention relates to a ribbon or web moving mechanism in the vertical direction, and more particularly to a mechanism for moving a print ribbon separated into horizontal coloring strips in order to apply a desired color to the print medium in a printer.

Conventional prior art systems for moving colored ribbons have the entire ribbon cartridge moved. A stepping motor or solenoid moves the entire ribbon cartridge to different heights in order to print different color strips. This technique requires a large prime mover with a significant amount of chord movement and also limits precision because control arms are far from each other and no contact or vertical guidance occurs near the printhead itself. The problem of tolerance is usually solved with a slight adjustment or the use of wider bands to compensate for the error.

In a wide printer, the entire carriage shifter may also be provided with a wire across the printer to prevent the printer ribbon from sagging. This technique allows for the use of narrower band strips, but still requires adjustment screws to compensate for molding tolerances.

Another prior art instrument is a solenoid mounted directly on a printhead with an endurance mechanism for keeping the ribbon close to the solenoid to precisely control movement. This is more accurate than the prior art instrument described above because it controls the ribbon very close to the frithead. This is also more accurate than the prior art mechanism described above because it is controlled very close to the printhead. However, the speed of travel is severely limited by the mass of the solenoid. Also, a large amount of power is consumed to move quickly.

In a preferred embodiment, the present invention includes an impact printer with a ribbon having horizontal colored strips to function color printing. The printhead is mounted on a carriage that traverses the width of the print medium on which printing is to be made. The print ribbon moves horizontally with respect to the printhead. A lightweight ribbon stage or ribbon moving mechanism engages the print ribbon within the ribbon guide and slidably engages within the carriage. A ribbon stage or ribbon moving mechanism is attached to a pair of racks, each rack having a gear portion moving through the carriage. The gear shaft is engaged with the rack gear so that the rack moves up and down when the shaft rotates. When the rack is moved, the ribbon stage or moving mechanism is also moved up and down to convey the print ribbon to a predetermined position so that a specific color is printed. Ribbon stages, racks and ribbons are the only components that move vertically in the present invention so that their movement can be achieved very easily when combined with a low inertia gear shaft which is a splined gear.

It is a primary object of the present invention to provide a color printer which can move very quickly from one color to another.

Another object of the invention is to provide a mechanism for moving a web in a vertical direction at a workstation.

These and other objects will be apparent in the detailed description that follows.

The present invention moves the endless web (print ribbon) in the vertical direction with respect to the print medium in the preferred embodiment for color printing. The amount of inertia to overcome in order to perform this movement is minimized by using a very lightweight ribbon stage or moving mechanism to vertically move the lightweight rack, which engages the ribbon and the relatively low inertia gear shaft, all of which are described below. It is described in detail in.

Referring to FIG. 1, there is shown a perspective view of a printer 857 type from Texas Instruments.

2 shows a frame 11 in a housing of the printer 10 and a printhead 12 mounted on a carriage 13 in which a ribbon stage or moving mechanism 14 is located in place. The gear shaft 15 is driven by the stepping motor 19. Motor 21 drives platen 22. The motor 35 drives the belt 36 to move the carriage 13. The ribbon drive 37 is driven by a pulley 38, which is driven by a belt 36. A ribbon guide 34 is positioned to guide the ribbon in its path.

FIG. 3 shows the components of FIG. 2 in an exploded view to clearly show the ribbon stage or moving mechanism 14 with the rack 16 positioned on the ribbon stage or mobile furniture 14. The components of FIG. 2 are shown in exploded view to clearly show the ribbon stage or moving mechanism 14 in the space defined by the vertical arms 13a to 13d. Also shown is a carriage 13 shaped to accommodate the ribbon stage or moving mechanism 14 in the space defined by the vertical arms 13a to 13d. The gear shaft 15 ends at the bevel gear 23 which meshes with the bevel gear 18. The bevel gear 18 is connected to the shaft 19a of the stepping motor 19 which drives the spline gear shaft 15. In this preferred embodiment, the stepping motor selected is the Fuji SM-55 type with a step angle of 7 (1/2) degrees. Of course, this choice can be chosen by the designer. Other stepping motors as well as other types of drive sources may be selected.

4 shows a ribbon 20 having black, blue, red and yellow strips. These colors are for example only. The print ribbon 20 is sandwiched between the protrusions 24 on the ribbon stage or movement mechanism 14 through the slot 25.

A rack 16 is shown rotatably mounted on a ribbon stage 14. The rack 16 protrudes through the slot 31 in the carriage 13. A spring 17 is also fitted in the slot 31 to bring the gear 32 into contact with the spline gear shaft 15. The carriage 13 is shown slidably mounted on the carriage rod 26. The stepping motor 19 drives the bevel gear 18, which in turn meshes with the bevel gear 23.

The bevel gear 230 is connected to the spline gear shaft 15 to pivot in response to the operation of the motor 15.

The motor 19 of FIG. 4 is a manual or computer generated control signal for driving the motor 19 at a distance and in a direction suitable for positioning the ribbon 20 of a suitable color in line with the printing end of the printhead 12. Answer When a current is applied to the stepping motor 19, the bevel gear 18 pivots the interlocking bevel gear 23, and the bevel gear 23 pivots the gear shaft 15. The gear shaft 15 meshes with the gear 32 of the rack 16 to move the gears 32 up and down in accordance with the rotation direction of the motor 19. For example, moving upwards rack 16 lifts up ribbon stage or moving mechanism 14. The ribbon 20 rises with the ribbon stage or moving mechanism 14 in the slot 25. Print media (not shown) is placed directly behind the ribbon to receive the desired color printing.

4 illustrates the use of a spline gear shaft 15 that engages the gist of the present invention, that is, a lightweight rack stage 16 coupled to a lightweight ribbon stage or movement mechanism 14. This combination reduces the inertia required to move the ribbon 20 in the vertical direction and increases the speed, which in this preferred embodiment is within about 30 milliseconds.

Those skilled in the art may modify materials and shapes without departing from the scope and scope of the invention, which is limited only by the appended claims.

Claims (11)

A rack moving device including a frame and having a print ribbon for providing to a printing position, the device comprising: (a) a ribbon moving device formed to include a print ribbon guide, (b) a rack device attached to the ribbon moving device and having a gear rack portion; (c) a slidably receiving ribbon moving device, the carriage device engaging the gear rack portion at least partially through the carriage device, and (d) having a printing end to contact the print ribbon when printing is desired. A printhead device with a printing end positioned adjacent to the print ribbon, (e) rotatably mounted on the frame, engaged with the gear rack portion to move the rack device vertically, and then the ribbon mover and print ribbon vertically A gearshaft device for adjusting the vertical position of the print ribbon with respect to the printing end by moving it a predetermined distance, and (f) mounted on the frame And a drive device coupled to the gear shaft device to selectively rotate the gear shaft device in both directions. The printer of claim 1 wherein the ribbon moving device includes a plurality of protruding arms spaced apart to form a print ribbon guide. A printer according to claim 1 or 2, wherein the carriage device comprises vertical arms that form slots for slidably receiving the ribbon moving device. 3. A ribbon according to claim 1 or 2, wherein the ribbon is separated into a plurality of horizontally colored strips, and the drive device rotates the gearshaft device enough to align the printing end with the desired horizontally colored strip. printer. The printer as claimed in claim 1, wherein the driving device comprises a stepping motor. A ribbon mover comprising a frame, using a print ribbon, (a) a ribbon mover formed to include a print ribbon guide, (b) a rack device attached to the ribbon mover and having a gear rack portion, and (c) moving horizontally And a carriage device so as to slidably receive the ribbon moving device, the gear rack portion engaging at least partially through the carriage device, and (d) having a printing end so as to contact the print ribbon when printing is desired. An impact printhead device positioned to have a printing end adjacent to the print ribbon, (e) rotatably mounted on the frame, engaged with the gear rack portion to move the rack device vertically, and then the ribbon mover and print ribbon Gearshaft positioned to adjust the vertical position of the print ribbon with respect to the printing end by moving it vertically by a distance Value and, (f) mounted on the frame, the impact printer for the gear shaft device characterized in that it optionally includes a drive device that is connected to rotate in both directions. The printer of claim 1 or 2, wherein the printhead device comprises a wire matrix linthead of stored energy. A web moving device including a frame and configured to (a) be positioned at the workstation and include a web guide for receiving the web, and (b) attached to the web moving device and geared to move the web through the workstation. A rack device having a rack portion, (c) a carriage device slidably receiving the web moving device, the carriage device being configured to pass through the gear rack carriage device, and (d) rotatably mounted on the frame, the gear rack A gear shaft device positioned to adjust the vertical position of the web by engaging the portion to move the rack device vertically, and then moving the ribbon moving device and the print ribbon vertically a predetermined distance, and (f) mounted on the frame, And a drive device coupled to selectively rotate the shaft device in both directions. The printer of claim 1, wherein the printer has a mobile print station and a print ribbon moving relative to the mobile print station. 10. The printer as claimed in claim 9 wherein the carriage device is connected to the device for moving the print station and is mounted to move across the print media. 10. The printer as claimed in claim 1 or 9, wherein the printhead device is a printhead device connected to a carriage device.

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