JPH03136879A - Printing apparatus - Google Patents

Abstract

PURPOSE:To obtain a printing apparatus with high printing quality and good running characteristic of a tape by providing right and left side plates, each with a hole larger than a second shaft, at the rear end of a platen frame provided with a jaw part for guiding a leading end of a printing paper. CONSTITUTION:In this printing apparatus, a platen frame 14 is supported by a first shaft 15, a second shaft 16 and left and right side plates 23, 24. The second shaft 16 if fixed to one point by a fixing ring 25. After a printing paper 22 guided by a frame 21 from a paper feed roller 20 is set at a predetermined set position, a printing head 11 is moved to be brought into pressed contact with a platen rubber 12. The second shaft 16 is moved to an upper end within a hole 26 of each side plate around the first shaft 15 at the front face of the platen frame 14, so that the platen frame is turned movable in the same direction as the movable direction of a platen. Since a leading end of the printing paper 22 is in touch with a jaw part 14b of the platen frame 14 when the printing paper 22 is sucked in, the platen frame 14 is consequently turned movable. Accordingly, a printing apparatus with high printing quality and smooth running characteristic is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a printing device in which a print head prints a character pattern on printing paper via an ink ribbon.

BACKGROUND OF THE INVENTION In recent years, printing devices have rapidly become faster, more multifunctional, and have higher printing quality in response to market needs. In particular, with regard to printing quality, it has become possible to print even kanji characters with a large number of strokes and delicate graphics by increasing the printing dot density, and higher printing quality is being demanded.

A conventional printing device will be explained below.

FIGS. 4a and 4b show side views of the main parts of the printing mechanism of a conventional printing device. In Fig. 4, 1. Title of the Invention Device 2. Claims 0) A platen configured by fixing a platen rubber to which the print head is pressed through the printing paper to a thin platen plate. , the platen is held at the front surface so as to be movable in the same direction as the print head, and is movable in the same direction as the platen around a first support provided on the front surface. and a platen frame supported by the left and right side plates, and a second support supported by the hole in the left and right side plates is provided on the rear end side of the platen frame, and the hole in the left and right side plate is inserted into the hole. Printing characterized in that the second support is configured to be larger than the second support so that it can move, and when the print head is pressed against the platen side, the second support is located at the upper end of the hole in the left and right side plates. Device.

(2) Printing paper percentage on the front of the platen frame
1 is the print head, 2 is the platen rubber with which the print head 1 is pressed through the printing paper, and 3 is the platen rubber 2.
A thin platen base 4 to which the platen rubber 2 is fixed to the platen base 3 has a protrusion 4! on its front surface so that the platen, which is constructed by fixing the platen rubber 2 to the platen base 3, can be moved in the same direction as the print head 1. A platen frame 6 holds the platen rubber 2 fixed thereon, and a platen frame 6 holds the platen frame 5 inside the platen frame 6 so that the platen frame 5 can be moved in the same direction as the print head 1. It is a coil spring with elastic force attached to.

The operation of the printing device configured as described above will be described below.

First, the movable platen mechanism shown in FIG. 4a will be explained.

The movable platen mechanism is a mechanism in which the platen moves following the pressing or opening operation of the print head 1. That is, the print head 1 performs press contact or release operation of the head via a motor or a leaf spring, but at that time, the platen is held by the protrusion 41L provided on the front surface of the platen frame 4. When the print head 1 is pressed into contact with the print head 1, the platen base 3 comes into contact with the protrusion 4a, and the platen presses against the print head 1.
This is a mechanism that moves in the same direction as the movement direction of the print head 1, causes the movement of the platen to follow the movement of the print head 1, and equalizes the vertical contact surface pressure between the print head 1 and the platen rubber 2.

Next, the movable platen frame mechanism shown in FIG. 4 will be explained. The movable platen frame mechanism is a mechanism in which the platen frame 5 moves following the pressing or opening operation of the print head 1. In other words, when the print head 1 performs a pressure contact or release operation of the head via a motor or a leaf spring, the coil spring 6 is installed inside the platen frame 6. The coil spring 6 is pressed through the platen rubber 2, and the elastic force of the coil spring 6 causes the platen frame 6 to move in the same direction as the print head 1 movement, similar to the movable platen mechanism, and the platen frame 6 moves in the same direction as the print head 1 movement. This is a mechanism that follows the movement of the print head 1 and the platen rubber 2 to equalize the vertical contact surface pressure between the print head 1 and the platen rubber 2.

Problems that the invention aims to solve However, in the above-mentioned conventional single mechanism configuration.

When the paper thickness of the printing paper increases, the movable range of the platen and platen frame is restricted due to its structure, so the movable range of the platen and platen frame is insufficient, and the vertical contact surface pressure between the print head and the platen rubber increases. This method has disadvantages in that it may not be uniform and the printed pattern may become partially thin, which is a so-called printing defect, and furthermore, the ink ribbon may not be completely wound, which may cause tape running defects.

The present invention solves the above-mentioned conventional problems, and aims to provide a printing device with high print quality and good tape running.

A means to solve problems To achieve this objective, the printing device of the present invention is provided.

A platen rubber to which the print head is pressed through the print paper, a thin platen base to which the platen rubber is fixed, and a platen configured by fixing the platen rubber to the platen base, movable in the same direction as the movement direction of the print head. The platen is supported on the left and right side plates so as to be movable in the same direction as the moving direction of the platen around a first support provided on the front side, and is attached to the lower end of the paper supply side. A platen frame is provided with a jaw portion that guides the leading edge of printing paper in contact with the platen frame, and a second column is provided on the rear end side of the platen frame to be supported by holes in the left and right side plates. It has left and right side plates each having a hole larger than that of the second column so that the column can move.

Function: With this configuration, the platen frame moves when printing paper is sucked in, and the press-contact operation of the print head allows the platen frame to move in the same direction as the platen, increasing the range of movement of the platen. This makes it possible to make the vertical contact surface pressure between the print head and the platen rubber more uniform, thereby improving print quality and tape running.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional view of the main parts of a printing mechanism of a printing device according to a first embodiment of the present invention.

In FIG. 1, 11 is a print head, 12 is a print paper 2
A platen rubber 13 is pressed into contact with the platen rubber 12 through a platen base 13, which is a thin platen base to which the platen rubber 12 is fixed, and a platen 14, which is constructed by fixing the platen rubber 12 to the platen base 13, is movable in the same direction as the movement direction of the print head 11. A protrusion 14 & is provided on the front part to hold it so that it can be held.
The paper supply side is supported on the left and right side plates along with a second support 16 on the rear end side so as to be movable in the same direction as the moving direction of the platen around a first support 16 provided on the front side. 17 is a head holder that holds the print head 11; 18 is a frame that presses or releases the print head 11; head 1
1 is a head release lever that makes a reciprocating motion; 19 is a driven roller that feeds the inserted printing paper 22 by following the paper feed roller 2o; and 21 is a frame that guides the paper feed from the paper feed roller 20. be.

The operation of the printing apparatus configured as described above will be described below with reference to FIGS. 1, 2, and 3.

First, FIG. 2 shows a schematic assembly diagram of the main components of the printing device in the first embodiment of the present invention.
The platen 7 frame 14 is held by the first support 16 and the second support 16 and the left and right side plates 23 and 24, and the fixing ring 2
6, one support 16 is fixed and attached at one location.

Further, FIGS. 3a and 3b are schematic diagrams illustrating the operation of the main components shown in FIGS. 'a1 and 2 in the first embodiment of the present invention. The holes 26 in the left and right side plates are configured to be larger than the second column 16 so that the second column 16 can move within the holes.

Figure 3a shows the position when the head is opened, and Figure 3A shows the position when the head is pressed against the head.During the head opening operation, the second support 16 is located at the lower end of the hole 26, but when the head is pressed against the head. During operation, it is shown that it moves to the upper end within the hole 26.

In FIG. 1, when the head release lever 18 is moved in the vertical direction via a motor or a leaf spring, the head holder 17 holds the print head 11 and is attached to the head release lever 18, so the head is pressed into contact or Perform the opening operation. The printing paper 22 guided and sucked into the frame 21 from the paper feed roller 2o is transferred to the paper feed roller 2o.
After setting the paper to a predetermined paper setting position using the roller 0 and the driven roller 19, when the print head 11 is pressed against the platen rubber 12, the print head 11 is pressed against the platen rubber 12.

At this time, since the platen in which the platen rubber 12 and the platen base 13 are fixed is held by a protrusion 141L provided on the front surface of the platen frame 14, the platen base 13 comes into contact with the protrusion 14a.

A movable platen mechanism in which the platen moves in the same direction as the print head 11 is operated.

Moreover, when the platen frame 14 is pressed, from the configuration explained in FIG. The platen frame 14 is moved to the upper end within the hole 26.
The movable grating frame mechanism moves in the same direction as the platen.

Furthermore, since the platen frame 14 is provided with the jaw portion 14b, when sucking the printing paper 22, the printing paper 22
The tip of the platen frame 14 comes into contact with the jaw portion 14b of the platen frame 14. Therefore, the platen frame 14 moves following the suction of the printing paper 22.

As described above, according to this embodiment, the platen is held by providing a protrusion on the front side so that it can move in the same direction as the print head, and supports are provided on the front and rear ends of the platen. By adopting a platen frame that is supported through the left and right side plates and has a jaw at the lower end of the paper supply side, the platen frame moves when printing paper is taken in. It becomes possible to move the platen frame together in the same direction as the moving direction.

Effects of the Invention As described above, the present invention provides a movable platen mechanism that holds a platen at the front, and a movable platen that supports a platen frame having supports at the front and rear ends so as to be movable within the holes in the left and right side plates. By providing a frame mechanism, both the platen and the platen frame can be moved in the same direction as the print head movement direction, and by providing a jaw at the lower end of the paper supply side, Since the platen frame moves according to suction, the range of movement of the platen becomes larger, and the contact pressure between the print head and the platen rubber becomes more uniform even when paper thickness increases, improving print quality. Furthermore, it is possible to realize an excellent printing device that can improve the performance of the tape and also make the tape run smoothly.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of the printing mechanism of the printing device in the first embodiment of the present invention, Fig. 2 is a schematic assembly diagram of the main components of Fig. 3, and Figs. 4A and 4B are side views of the main parts of the printing mechanism of the conventional printing device. 11... Print head, 12... Platen rubber, 13... Platen base, 14...
...Platen frame, 14b...Jaw part,
15.16... Support column, 22... Printing paper, 23... Left side plate, 24... Right side plate.

Claims (2)

[Claims] (1) A platen that is constructed by fixing a platen rubber to which the print head is pressed via the print paper to a thin platen base, and a front surface that allows the platen to move in the same direction as the print head. and a platen frame supported on left and right side plates so as to be movable in the same direction as the platen moving centering on a first support provided on the front side of the platen frame, and a rear end of the platen frame. A second support supported by the hole in the left and right side plates is provided on the side, and the hole in the left and right side plate is configured to be larger than the second support so that the second support can move within the hole,
When the print head is pressed against the platen side, the second
A printing device characterized in that the pillars are located at the upper ends of the holes in the left and right side plates. (2) When feeding print paper between the print head and platen, the leading edge of the paper is brought into contact with the lower end of the print paper supply side of the front part of the platen frame, and guided between the print head and platen. 2. The printing device according to claim 1, further comprising a jaw portion that allows the printing device to print.