JPH0688412B2 - Small printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a small-sized printer that prints by printing a character on a character wheel made of an elastic material such as rubber from the inside.

[Prior Art] A conventional small-sized printer of this type is disclosed in
As disclosed in 58-134752, there is a mechanism for pressing and printing from the inside of a type wheel that carries a carrier while rotating by using a hammer that pivotally supports a rotatable roller. (Refer to FIG. 6) However, in the case of this mechanism, in order to bring the tip of the hammer into accurate contact with the pressing position corresponding to the type in order to press only the required type, the precision of each part that constitutes the mechanism is improved. However, it is difficult to steadily press the type because the contact position between the tip of the hammer and the type wheel changes during the printing process. Therefore, there are problems such as missing characters and printing of adjacent characters, and in order to improve them, the cost of parts and the number of assembly steps increase.

A type ring used in this type of printing mechanism is disclosed in
As shown in -146659, a thin portion is provided between each type and the thin portion is bent to improve the drawbacks such as the deformation of the type when pressing and the stain of the print by the adjacent type. However, the area occupied by the thin-walled portion between the printing characters in the circumferential direction of the printing wheel becomes large, and it was inevitable that each printing area should be reduced or the diameter of the printing wheel should be increased to make room.

The present invention has been made to solve such drawbacks, and its intent is to provide a small-sized printer that ensures high printing quality without ejection of characters and stains due to adjacent character printing by reliably and accurately pushing out characters. To provide.

[Means for Solving the Problems] Therefore, in order to solve the above-mentioned problems, a small printer of the present invention has a type wheel formed of an elastic body having a type on the outer circumference and a type wheel wound around the circumference. It has a type wheel holder that is driven to rotate, and a hammer that has a first head that presses the type of the type wheel from the inside of the type wheel holder onto printing paper to print, and the hammer is a type character to be printed. Is characterized in that at least one second head for pushing out the characters adjacent to each other in the circumferential direction is disposed.

[Operation] According to the above configuration of the present invention, when a hammer presses a print character, the second head of the hammer pushes out the adjacent print character to increase the surface curvature of the print character. The tension is weakened and the deformation of printed characters due to the tension is reduced.

[Examples] Hereinafter, details of the present invention will be described based on illustrated examples.

FIG. 1 shows a printing mechanism portion of an apparatus according to the present invention, in which reference numeral 10 is attached to a frame 1 so as to be guided by a guide shaft 2 fixed to a frame 1 so as to be movable in a digit feeding direction. It is a carriage, and a shaft 11 is formed on the upper surface of the carriage 10 so as to project upward. As shown in FIG. 2, a type wheel holder 16 formed in a cage shape is loosely fitted to the shaft 11, and a type wheel made of an elastic body in which the type characters 13-1 are arranged.
The type gear 12 is press-fitted into a sleeve 17 which holds 13 and is formed in the lower part of the type ring body, and the type wheel 13, the type wheel holder 16 and the type gear 1 are driven by a driving means (not shown).
2 rotates together. On the other hand, at one end of the carriage 10, a hammer lever 23, one end of which reaches the inside of the type wheel 13 and the type wheel holder 16, is rotatably attached to a shaft 25, and the tip of the lever 23 is of the type wheel 13. In the concave hole 23-1 provided near the intersection with the central axis, the type 13-1 on the type wheel 13
The hammer 24 for pushing out the protrusion 13-2 formed on the inner periphery of the type 13-1 by pushing it outward from the back and causing the type 13-1 to protrude is rotated in the same plane as that in the type wheel 13. Installed so that you can. In addition, hammer 24
The spring 28 is urged counterclockwise in the figure so that the tip of the arm 24-1 always faces the upper side in the rotational direction of the printing wheel 13 from the platen surface 91, and the printing wheel positioned there is in the initial stage of printing. It is configured to face the protruding portion 13-2.

FIG. 2 shows the main part of the whole apparatus according to the present invention, and includes the mechanical part shown in FIG. 30, 40 in the figure
Is the rotation of the type wheel 13 and the type holder 16 for selecting the type by meshing with the type gear 12 on the carriage 10, and the carriage feed of the carriage 10 and the home position side of the carriage 10 (the right side in the figure). The first and second worms for performing the return to the above, form a kind of differential mechanism with the type gear 12, and are parallel to the carriage feed direction.
Moreover, the shafts at both ends are rotatably protected by the frame 1. Gears 32 and 42 are attached to one ends of the shafts of these worms, respectively, and the rotational force from the motor 50 that constantly rotates during the operation of this position is selectively applied to the first worm 30 or the second worm 40. It is driven by the output of the clutch 100 that transmits intermittently. Select, print,
Clutch 10 in each carriage shift and return stroke
The operation of 0 will be described in the following operation description.
Further, 29 in FIGS. 1 and 2 is an ink roller for transferring ink to the type 13-1 on the type wheel 13 in accordance with the rotation of the type wheel 13 and is rotatably mounted on the carriage 10. Reference numeral 91 is a platen having a printing surface parallel to the carriage feed direction α, and a printing paper (not shown) is attached to the surface thereof. Reference numeral 26 in FIG. 2 denotes a shaft 23 which is attached to the above-mentioned hammer lever 23 perpendicularly to its swinging surface.
-2 is a swinging claw that is rotatably attached to the carriage and is constantly urged in the horizontal direction by a spring 27.
During the carry-up process in the α direction of 10, the hammer lever 25 is swung by engaging with the print rack 5 which is fixed to the frame 1 and is composed of cam teeth for the number of print digits. Each of the cam teeth of the print rack 5 has a vertical cam surface 5-1 on the lower digit side and an upward slope 5-2 on the upper digit side.
When the carriage 10 is carried in the α direction, the swinging claw 26 and further the hammer lever 23 are swung in the γ direction in the drawing along the cam surface 5-1 as described above, and when the carriage 10 is returned, the upward slope 5-2.
The oscillating claw 26 alone is oscillated in the direction perpendicular to the paper surface of FIG.

Next, the operation of the above-mentioned device will be described.

(Selection of print type) When the print type is selected, the clutch 100 in FIG. 2 operates to transmit the rotational force from the motor 50 so as to rotate both the first and second worms in the ε and Ψ directions, respectively. . In addition, the first and second worms in this state rotate at the same rotation speed,
The type gear 12, which meshes with this to form a differential mechanism, rotates in the β direction in the figure without moving its rotation axis. This state continues until the desired type on the type wheel 13 that rotates integrally with the type gear 12 faces the printing surface 91.

(Carrying and printing) When the desired type is selected, the operating state of the clutch 100 is switched by the print position detecting means and the control means of the clutch 100, which are not shown, and the clutch has been rotated until then.
Transmission of the driving force to the worm 40 of the
The worm 40 is held in a defined phase. Therefore, the type gear 12 is driven by the first worm 30 that continues to rotate and rolls on the stopped second worm 30, and the carriage 10 moves leftward in the drawing while the first worm rotates a predetermined angle. Run one digit. Along with this traveling, the swinging pawl 26 is pushed up by the cam surface 5-1 of the rack 5, the hammer lever 23 integrated with this is rotated in the γ direction in the figure, and the hammer 24 pivotally supported at one end thereof. Is extruded toward the protrusion 13-2 on the inner circumference of the type wheel corresponding to the desired type. (FIG. 3 (a)) As a result, the printing operation is started, and as shown in FIG. 3 (b), as the type wheel 13 further rotates in the β direction in the figure, the head 24-1 of the hammer is moved to the type wheel. It is inserted between the radial wall 16-1 of the holding body 16 and the wall next to it, and the characters 13-
1 is projected, but since the hammer 24 is biased counterclockwise by the spring 28, the head of the hammer is in contact with the radiation wall 16-1 on the left side of the protrusion 13-2 on the back side of the type to be printed. Therefore, the contact point between the hammer head 24-1 and the printing wheel projection 13-2 is constant with almost no deviation, and the printing head is guided by the radial wall 16-1 of the printing wheel holder. The type is pressed together with the rotation of the wheel 13. At this time, since the pitch circle radius of the type gear and the distance from the center of rotation of the type gear to the printing surface are set to be the same between the type 13-1 and the printing surface 91, the relative speed is zero, and 13-1 is pressed against the printing paper (not shown) on the printing surface 91 without slipping. In this printing state, the swing claw 26 attached to the hammer lever 23 is mounted on the rack 5
When the swing claw falls between the cams of the rack 5, the hammer lever 23 rotates in the −γ direction in FIG. The hammer 24 separated from the protrusion 13-2 on the back surface of the type 13-1 is also rotated counterclockwise in the figure by the urging force of the spring 28 (FIG. 3 (C)), and again in FIG. It returns to the state of and enters the next selection process.

By the way, the hammer 24 has a head for pressing the characters described above.
A second head 24-2 (Figs. 3 and 4) is formed on both sides of 24-1 so as to come into contact with the protrusions on the back surface of the typeface adjacent to the typeface to be printed. At the same time as the print characters are pressed against the printing surface, the print characters on both sides of the print characters are also slightly projected so as not to contact the printing paper. As a result, the type wheel 13 slightly bulges toward the printing surface side as shown in FIG. 4, and the curvature near the pressed type is alleviated. The left and right edges are also clearly printed.

Also, as shown in FIG. 4, the hammer second head portion 24-2 is contacted on the side away from the hammer first head portion 24-1 with respect to the center line 13-4 of the printing character back projection portion 13-2. A rotation moment in the direction of the arrow in the figure is applied to the protrusions on the back surface of the printed characters that are in contact with and are adjacent to the printed characters to be printed. Therefore, this protrusion is separated from the radial wall 16-1 of the character holding body as compared with the case where the second head 24-2 of the hammer is not attached (as indicated by the two-dot chain line in the figure). And it is pushed out smoothly.

On the other hand, regarding the type wheel 13 in the present embodiment, as shown in FIG. 4, the type on the outer peripheral surface of the type wheel is displaced by a predetermined amount in the counterclockwise direction in the figure with respect to the protrusion 13-2 of the type wheel. Are arranged. This is because the head 24-1 of the hammer is the type wheel holder 16-
When the hammer 24 is guided by 1 and pushed out, the hammer 24 is urged in the counterclockwise direction in FIG. 4 by the above-mentioned spring 28 to radiate the type ring holders on both sides of the protrusion 13-2 on the back side of the type to be pressed. This is a means for offsetting the hammer head to the left side in the figure from the centrally allocated position of the wall 16-1, and the deviation of the type 13-1 with respect to the protrusion 13-2 on the back of the type is printed. In the state of directly facing the surface (Fig. 4), the point 24-3 where the hammer head comes into contact with the type ring and the type center paper are set so as to be on a line perpendicular to the printing surface. . As a result, the printed characters are not biased to the left or right with respect to the center line thereof.

Further, as shown in FIG. 5, the characters on the type wheel 13 have different character shapes when they are not printed (FIG. 5 (a)) and when they are printed (FIG. 5 (b)). Expands laterally as you extrude. This phenomenon is caused by intentionally reducing the circumferential distance between the printed characters as in this embodiment, and the thin portion of the printed wheel is
This tendency becomes particularly noticeable when 13-3 is shortened to reduce the diameter of the type wheel. In the present embodiment, in FIG. 5, the regions c and d at both ends of the printed character hanging on the thin portions on both sides of the printable ring protrusion, that is, the portion that is particularly likely to expand in the circumferential direction by hammer extrusion, , The print shape is reduced toward the center of the print and corrected. (Except for characters with a narrow width such as "1" and ".") Therefore, a character with a width larger than that of the printed characters arranged on the printing wheel 13 is printed while satisfying the desired shape.

(Carriage return) As described above, selection, carry up, and printing are performed for each digit, and by repeating this for a predetermined number of print digits, printing of one line is completed, and the carriage returns to the home position. While the carriage is returning, the clutch 100 shown in FIG.
The transmission of the driving force to the first worm 30 which has continued to rotate until then is stopped to put the first worm in a stopped state, and at the same time, the second worm acts so as to rotate in the Ψ direction. Then, by the differential mechanism composed of the first worm 30, the second worm 40, and the type gear 12, the carriage supporting the type gear 12 is moved in the right direction in the figure contrary to the above-mentioned carry. This state continues until the carriage returns to the home position.

During the carriage return process, the swinging pawl 26 that meshes with the cam of the rack 5 has a shaft 23- formed on the hammer lever 23.
While swinging up and down about 2 as a fulcrum, it goes over the upward slope 5-2 provided on the left side of each cam surface 5-1, so that the returning operation is smoothly performed without operating the hammer lever 23.

Further, in the present embodiment, although not shown in the figure, the clutch 100 is provided with a paper feeding unit that starts the operation in synchronization when the operation is switched to the carriage returning state, and the printing of the next line from the carriage returning is performed. Feed a line of paper before entering.

[Effects of the Invention] As described above, according to the present invention, a type wheel having a type on the outer periphery and formed of an elastic body, and a type wheel holder that is rotationally driven by winding the type wheel on the circumference. And a hammer having a first head for printing the printing of the printing wheel from the inside of the printing wheel holder on the printing paper, the hammer being the printing characters adjacent in the circumferential direction of the printing character. Since at least one second head for pushing out is arranged, the second head of the hammer pushes out the adjacent type to increase the surface curvature of the type to be printed, and the tension of the adjacent type becomes weak. The deformation of the printed characters due to the tension is reduced, the missing characters are eliminated, and the printing quality is greatly improved.

Further, since the radius of curvature of the type wheel during printing can be increased and the diameter of the type wheel holder can be reduced, miniaturization of the printer can be achieved and the practical effect of the present invention is extremely large. is there.

[Brief description of drawings]

FIG. 1 is a plan view showing a printing mechanism portion of a small printer showing an embodiment of the present invention. FIG. 2 is a plan view showing an embodiment of a small-sized printer including the same mechanical section. 3, 4, and 5 are plan views showing the main operation of the printing mechanism section. 6 and 7 are diagrams showing a conventional example. 5 …… Rack 10 …… Carriage 12 …… Type gear 13 …… Type wheel 16 …… Type wheel holder 23 …… Hammer lever 24 …… Hammer 30,40 …… Warm 100 …… Clutch

Claims (1)

[Claims] 1. A type ring having a type on the outer periphery and formed of an elastic body, a type ring holder that is rotatably driven by winding the type ring on a circumference, and from the inside of the type ring holder. A hammer having a first head for pressing the type of the type wheel onto a printing sheet for printing, and the hammer having a second head for pushing out the type adjacent to the printed type in the circumferential direction. A small printer having at least one of the above.