JPS62193832A - Small-size printer - Google Patents

Abstract

PURPOSE:To enable smooth extraction of types and thereby sharp printing by providing the first head which contacts a protrusion at the back of a type and the second head which contacts an adjacent protrusion and causing the first head to contact the protrusion at a required type with a guide means. CONSTITUTION:A hammer 24 is energized by a spring 28 into a counter-clockwise direction, so that a head is pushed out in close contact with a radial wall 16-1 at left of a protrusion 13-2 at the back of a type to be used for printing. Therefore, the type is pressed almost without any shift of a contact point between a hammer head 24-1 and a protrusion 13-2. The second head 24-2 formed at both sides of the head 24-1 has a type pressed on a printing surface, and at the same time that this pressing is performed, adjacent types of both sides are allowed to protrusion to some slight extent. A type wheel 13 is slightly inflated to a type surface side, thus moderating a curvature near a pressed type and reducing the surface curvature of the type itself. This enables sharp printing at right and left ends of the type. In addition, the second head 24-2 gives a rotational moment to a protrusion at the back of an adjacent type, pushing out the type smoothly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a small printer, particularly a type ring made of an elastic material such as rubber, and prints by moving and rotating the type ring and pressing it from inside. This article relates to a small printer that uses various types of printing mechanisms.

[Prior Art] As disclosed in Japanese Patent Application Laid-Open No. 58-134752, conventional small-sized printers use a hammer with a freely rotatable roller at its tip to generate type that carries over while rotating. There was a mechanism for printing by pressure from inside the ring.

(See Figure 6) However, in the case of this mechanism, in order to press only the required type and to bring the tip of the hammer into precise contact with the pressing position corresponding to that type, the accuracy of each component that makes up the mechanism must be improved. It was difficult to press the type stably because the contact position between the tip of the hammer and the type wheel changed during the printing process. Therefore, there are problems such as missing characters and printing of adjacent characters, and improvement of these problems requires an increase in parts costs and assembly man-hours.

In addition, the type wheel used in this type of printing mechanism was developed in Japanese Patent Publication No. 5
7-146659, a thin wall portion is provided between each type character, and this thin wall portion is formed into a bent shape (
(See Figure 7) Although the drawbacks such as type deformation when pressed and print stains due to V4 contact type are improved, the area force f occupied by the thin part between the type in the circumferential direction of the type wheel increases, and each It was necessary to make room by reducing the type area or increasing the diameter of the type ring.

The present invention has been made to solve these drawbacks, and its purpose is to provide a compact printer that operates reliably and accurately pushes out type, and ensures high print quality without missing characters or smearing due to adjacent character printing. It is about providing.

[Means for Solving the Problems] That is, in order to achieve the above-mentioned object, the present invention has a device made of an elastic body, with printed characters arranged on the outer periphery, and protruding from the back surface corresponding to the printed characters. A type ring having a radial protrusion, a hammer integrally having a first head that abuts a protrusion on the back side of a required type, and a second head that abuts an adjacent protrusion; A lever that is pivoted so as to be able to swing by a predetermined amount while biasing it toward the standby position and pushing it out in the direction of suppressing the type, and a lever that holds the type wheel and further rotates the first head of the hammer during printing. a type holder having a hammer guide means provided so as to move in synchronization with the type and come into contact with only the protrusion on the back of the required type, and the second head of the hammer is adjacent to the type to be printed. The type is pushed out to such an extent that it does not hit the recording paper, and the second head of the hammer is formed to abut against the rear protrusion of the adjacent type at a position offset from the center of the protrusion on the side farther from the first head. .

[Function] With these technical means, in the small printer according to the present invention, in its printing mechanism, the first head of the hammer is moved only to the protrusion on the back surface of the required type of the type wheel by the hammer guide means provided on the type wheel holder. The second head of the hammer moves in unison with the rotation of the type wheel to suppress the type while making accurate contact with the type wheel, thereby preventing smearing of the print without printing errors on adjacent type.At the same time, the second head of the hammer Since the type is pushed out by a small amount, the deformation of the type to be printed, especially the surface curvature, is alleviated to prevent character chipping. Furthermore, the second head of the hammer is pushed out while coming into contact with the rear protrusion of the adjacent type at a position far from the center line of the second Qr mark, so that it comes into contact with the second head when pushing out the type. The protrusions are tilted to spread to both sides, and the back protrusions of the type are pushed out smoothly without biting into the type ring holder, which also helps prevent the type from deforming as described above.

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

FIG. 1 shows the printing mechanism section of the device according to the present invention, and the reference numeral 10 in the figure is attached to a frame 1 so that it can run in the feed direction while being guided by a guide shaft 2 fixed to the frame 1. A shaft 1 is mounted on the upper surface of the carriage 10.
1 is formed to protrude upward. This shaft 11 has a second
Type wheel holder 1 formed into a basket shape as shown in the figure.
6 is loosely fitted, and holds a type wheel 13 made of an elastic body with type letters 13-1 arranged therein, and a type gear 12 is press-fitted into a sleeve 17 formed at the bottom of this type wheel body. The type wheel 13 is driven by drive means (not shown). The type wheel holder 16 and the type gear 12 rotate together. On the other hand, at one end of the carriage 10, a hammer lever 23 whose one end reaches the inside of the type wheel 3 and the type wheel holder 16 is rotated around a shaft 25! 1lIJ can be freely installed, and
The concave hole 23-1 provided near the point where the tip of the lever 23 intersects with the center axis of the type wheel 13 is filled with the type 13-1 on the type wheel 13.
A hammer 24 for pushing out the protrusion 13-2 protrudingly formed on the inner periphery from the rear to cause the type 13-1 to protrude is rotated within the type wheel 13 in the same plane as the protrusion 13-2. installed in such a way that it can be moreover,
The hammer 24 is biased counterclockwise in the figure by a spring 28 so that the tip of the arm 24-1 always faces upward in the direction of rotation of the type wheel 13 from the platen surface 91, and is positioned there at the beginning of printing. It is configured to face the protrusion 13-2 of the type wheel.

FIG. 2 shows the main parts of the entire apparatus according to the present invention, including the horizontal section a shown in FIG. 30 in the figure.
40 meshes with the above-mentioned type gear 12 on the carriage 10 to rotate the type wheel 13 and type holder 16 for type selection, shift travel of the carriage 10, and operate the carriage 1.
0 to the home position side (right side in the figure) are the first and second worms, and are the type gear 12.
Together, they form a kind of differential mechanism, and the shaft portions at both ends are rotatably protected by the frame 1 in parallel to the direction in which the carriage is moved. Gears 32 and 42 are attached to one ends of the shafts of these worms, respectively, and the rotational force from the motor 50, which continues to rotate at all times during one operation of this position, is selectively applied to the first worm 30 or the second worm 110. It is driven by the output of the clutch 100, which transmits data intermittently to the engine. In addition, the clutch 100 is used in each process of selection, printing, carriage advance and return! 1iJ
J will be included in the description of the operation that follows. Further, 29 in FIGS. 1 and 2 is an ink roller for transferring ink to the type 13-1 on the type wheel according to the rotation of the type wheel 13. can be attached to. A platen 91 has a printing surface parallel to the moving direction α of the carriage 10, and a printing paper (not shown) is attached to the surface of the platen. 26 in FIG. 2 is a rocker which is rotatably attached to the shaft 23-2 which is attached perpendicularly to the rocking surface of the hammer lever 23, and which is always urged horizontally by a spring 27. It is a movable pawl, and engages with a printing rack 5 fixed to the frame 1 and consisting of cam teeth corresponding to the number of printing digits during the carry-up stroke of the carriage 10 in the α direction, thereby swinging the hammer lever 25. Each cam tooth of the printing 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, so that the carriage 10 can be carried up in the α direction. At times, as described above, the swinging pawl 26 and further the hammer lever 23 are swung along the cam surface 5-1 in the γ direction in the figure, and the carriage 1
When returning to 0, only the swing claw 26 is caused to swing in a direction perpendicular to the paper plane in FIG. 2 by the upward slope 5-2.

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

(Selection of Type) When selecting type, the clutch 100 in FIG. In order to rotate both second worms in the ε and φ directions,
It operates to transmit the rotational force from the motor 50. Also, in this state, the first. The second worm rotates at the same number of revolutions, and the type gear 12 that meshes with it to form a differential mechanism rotates in the β direction in the figure without moving its axis of rotation. This state continues until the desired type on the type wheel 13 , which rotates together with the type gear 12 , faces the printing surface 91 .

(Carry and printing) When the desired printed character is selected, the operating state of the clutch 100 is switched by the printed character position detection means and the clutch 1000 control means (not shown), and the second worm 40, which had been rotating until then, is moved. The transmission of the driving force W1 is cut off, and the second worm 40 is held in a predetermined phase.

Therefore, the type gear 12 is driven by the first worm 30 which continues to rotate, and moves over the stopped second worm 30, and while the first worm rotates by a predetermined angle, the carriage 10 is moved to the left in the figure. Run for digits. Along with this movement, the swinging claw 26 is pushed up by the cam surface 5-1 of the rack 5, and the hammer repper 23 integrated with the swinging claw 26 is pushed up by the cam surface 5-1 of the rack 5.
a hammer 24 that rotates in the direction and is pivoted at one end of the hammer 24;
is pushed out toward the protrusion 13-2 on the inner periphery of the type ring corresponding to the desired type. (Fig. 3 (a)) This starts the printing operation, and from then on, as shown in Fig. 3 (b), the printing wheel 13
As it further rotates in the β direction in the figure, the head 2 of the hammer
4-1 enters between the radial wall 16-1 of the type wheel holder 16 and the wall next to it and causes the type 13-1 to protrude,
Since the hammer 24 is urged counterclockwise by the spring 28, the head of the hammer is pushed out while contacting the radiation wall 16-1 on the left side of the protrusion 13-2 on the back side of the type to be printed. portion 24-1 and type ring protrusion 13-
The point of contact with the type wheel 13 remains constant with almost no deviation, and the force of the hammer head is guided by the radial wall l5-1 of the type wheel holder, and presses the type together with the rotation of the type wheel 13. At this time, the printed characters 13-1 and the printed surface 91 are
Since the pitch circle radius of the type gear and the distance from the rotation center of the type gear to the printing surface are set equal, the relative speed is zero, and the type 13-1 is printed on the printing paper (not shown) on the printing surface 91. ) without slipping. This printing state continues until the swinging claw 26 attached to the hammer lever 23 rides over the cam surface 5-1 of the rack 5. After that, when the swinging claw falls between the cams of the rack 5, the hammer lever 23 self-aligns. -γ in FIG. 3 due to the acting spring 28
Along with this, the hammer 24, which is separated from the protrusion 13-2 on the back side of the type 13-1, also rotates counterclockwise in the figure due to the biasing force of the spring 28 (see Fig. 3 (C)). )), the process returns to the state shown in FIG. 1 and enters the next selection process.

By the way, the hammer 24 has second heads 24-1 formed on both sides of the head 24-1 for suppressing the type mentioned above so as to come into contact with protrusions on the back of the type on both sides of the type to be printed.
2 (Figures 3 and 4), and at the same time the type is pressed against the printing surface, the type on both sides of it are also made to protrude a little to the extent that they do not touch the printing paper. As a result, the type ring 13 slightly bulges toward the printing surface as shown in Figure 4, and the curvature near the pressed type is relaxed, so the surface curvature of the pressed type itself becomes smaller, and the type The left and right edges are also clearly printed.

Further, as shown in FIG. 4, this hammer second head 24-2 is applied on the side away from the hammer first head 24-1 from the center line 13-4 of the type back projection 13-2. A rotational moment in the direction of the arrow in the figure is applied to the protrusion on the back of the type that is in contact with and adjacent to the type to be printed. Therefore, this protrusion is pushed out from the radial wall 16-1 of the type holder, compared to the way it would be pushed out if the second head 24-2 of the hammer was not attached (indicated by the two-dot chain line in the figure).・In this way, it is pushed out smoothly.

On the other hand, regarding the type ring 13, in this embodiment, as shown in FIG. 4, the type on the outer peripheral surface of the type ring is disposed counterclockwise in the figure by a predetermined distance fiHQ with respect to the protrusion 13-2 of the type ring. has been done. This is because when the hammer head 24-1 is guided by the type ring holder 16-1 and pushed out, the hammer 24 is urged in the counterclockwise direction in FIG. 4 by the spring 28, and presses the type. This is a measure taken to prevent the rehammer head from shifting to the left in the figure due to the center allocation position of the radial wall 16-1 of the type wheel holder on both sides of the protrusion 13-2 on the back of the type. Type 13 for part 13-2
-1 deviation is the point 24 where the hammer head abuts the type wheel when the type faces the printing surface (Fig. 4).
-3 and the type center paper are set so that they are on a line perpendicular to the printing surface. This prevents the type from being pressed to the left or right with respect to its center line.

Furthermore, as shown in FIG. 5, the shape of the type on the type wheel 13 changes between when it is not printed (FIG. 5(a)) and when it is printed (FIG. 5(b)). As it is extruded, it expands laterally. This phenomenon is particularly noticeable when the diameter of the type ring is reduced by intentionally making the circumferential distance between the type characters small and shortening the thin part 13-3 of the type ring as in this embodiment. The trend becomes noticeable. In this embodiment, in FIG. 5, the area C and the area D at both ends of the type that hang on the thin wall portions on both sides of the type ring protrusion, that is, the areas that are particularly easy to expand in the circumferential direction by hammer extrusion, are used. The correction was made by reducing the shape of the type toward the center of the type. (“1”
(excluding characters with narrow width such as "" and "pa'") Therefore, characters larger in width [11] than the type shape arranged on the type wheel 13 are printed while satisfying the desired shape.

(Return of Carriage) As described above, selection, carry, and printing are performed for each digit, and by repeating this for a predetermined number of printing digits, one line of printing is completed, and the carriage is ready to return to the home position. During the return of the carriage, the clutch 100 in FIG.
The transmission of the driving force to the first worm 30, which had been rotating until then, is cut off and the first worm is placed in a stopped state, and the second worm is moved in the -ψ force direction opposite to that when selecting type. It acts like 'li, II'. Then, by the differential mechanism composed of the first worm 30, the second worm 40, and the type gear 12, the carriage that pivotally supports the type gear 12 is sent to the right in the figure, contrary to the above-mentioned carry. is,
This state continues until the carriage returns to its home position.

During this carriage return process, the swinging pawl 26 that engages with the cam of the rack 5 swings up and down using the shaft 23-2 formed on the hammer lever 23 as a fulcrum, while moving each cam surface 5.
Since the return operation is carried out over the upward slope 5-2 provided on the left side of -1, the return operation is performed smoothly without operating the hammer lever 23.

Furthermore, although not shown in the drawings, this embodiment includes a paper feeding means that starts operating synchronously when the clutch 100 switches its operation to the carriage return state. A line of paper is fed before entering the line.

[Effects of the Invention] As described above, according to the present invention, the shift can be carried out at the same time as shifting!
The first head of the hammer that is pushed out from inside the type wheel is guided by the radial wall provided on the type wheel holder, and accurately contacts only the protrusion on the back of the type to be printed and presses the type. At the same time, since the second head of the hammer pushes out the adjacent type by a small amount to alleviate the surface curvature of the type to be printed, clear print quality without missing characters or adjacent characters can be ensured. In addition, the second head of the hammer exerts a moment that spreads the protrusions on the back of adjacent type to both sides of the protrusions on the back of the type to be printed, making it easier to pull out the type from the type wheel holder. .

[Brief explanation of drawings]

FIG. 1 is a plan view showing a printing mechanism section of a small printer showing an embodiment of the present invention. FIG. 2 is a plan view showing an embodiment of the small-sized printer including the same mechanical section as above. FIG. 3, FIG. 4, and FIG. 5 are all plan views showing the main operations of the printing a structure. Further, FIGS. 6 and 7 are diagrams showing conventional examples. 5...Rack 10...Carriage 12...Type gear 13...Type wheel 16...Pa/Type wheel holder 23...・ ・ ・Noh Marenoku-24・
... Hammer 30.40 ... Worm 100 ... Clutch or above Applicant Seiko Epson Co., Ltd. Representative Patent Attorney Mogami Munethi → To Figure 1 13-1, -. Figure 4 Figure 5

Claims (2)

[Claims] (1) In a printer that performs pressure printing by moving a type wheel to a required printing position and rotating it to select a desired type, the type is made of an elastic body and the type is arranged on the outer periphery, while the inner periphery is filled with the corresponding type. A type ring having protrusions projecting radially on the back surface of the type characters, a first head disposed so as to be able to come into contact with the protrusions on the back surface of the desired type characters, and a first head capable of coming into contact with the adjacent protrusions. an integrally formed hammer having a disposed second head; and a member that biases the hammer toward a standby position within the type wheel, and is pivotally supported to be swingable by a predetermined amount; A lever that pushes out the type in the pressing direction and the type wheel are held, and furthermore, during printing, the first head of the hammer moves in synchronization with the rotation of the type wheel and presses only the protrusion on the back of the desired type. A small-sized printer comprising a type holder having a hammer guiding means provided in contact with the type holder. (2) During printing, the first head of the hammer presses the required type, and at the same time, the second head pushes out the type adjacent to the type by an amount that does not touch the recording paper, and the second head presses the required type.
The small printer according to claim 1, wherein the head is formed to abut against the rear protrusion of the adjacent type at a position away from the first head from the center thereof. .