JPH0331349B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Application of the Invention The present invention relates to a printer, particularly a small and lightweight serial printer built into a printer-equipped calculator or the like.

[Background of the invention]

Recently, there has been a great demand for higher printing speeds for printers, and it is effective to use a so-called flying method for this purpose. However, in flying type printers, the type is usually constantly moving at high speed, so printing the desired type at a predetermined position in a timely manner is dependent on accurate detection of the type position, the operating speed of the hammer means, and the type. There are many technical difficulties, such as synchronizing the speed of movement.

The present invention was made to solve these technical difficulties, and its purpose is to create a stable relationship between the position of type and the timing of hammering in a flying type printer. The object of the present invention is to provide a printer that can provide accurate printing without printing errors and has improved reliability.

(b) Embodiment of the Invention [Overall Schematic Configuration] FIG. 1 is a schematic configuration diagram of a printer showing an embodiment of the present invention. A driving pulley 1 and a driven pulley 2 are arranged at a predetermined interval, and an endless type belt 3 having a large number of type parts arranged side by side on the outside is stretched between them. 1 serving as the driving source
A worm 5 is attached to the rotating shaft of the two DC motors 4, and the driving force of the motor 4 is transmitted to a planetary gear train 8 via a first idle gear 6 and a second idle gear 7. The planetary gear train 8 consists of one input section and two output sections, as will be described later. The driving pulley 1 is fitted into the input section, and one of the two output sections One has bevel teeth formed so that it can mesh with the print carry gear 9, and the remaining one is used as a dummy.

One end of a print carry shaft 10 is connected to the print carry gear 9, and this print carry shaft 10 is arranged between the driving pulley 1 and the driven pulley 2.
It extends parallel to the type belt 3. A hammer holder 11 is attached to the print carry shaft 10 so as to be slidable in the axial direction, and the hammer holder 11 has a built-in and supported hammer, carry paper feed cam, rack release lever, etc. as described later. . Further, one end of a holder return spring 12 is connected to the hammer holder 11, and the other end of the spring 12 is fixed to a base (described later).
is always elastically biased toward the home position side near the driven pulley 2 by the tensile force of the holder return spring 12.

A rack 13 is arranged near the printing carry shaft 10 and parallel to it, and the hammer holder 1
Carry paper feed cam built into 1 and rack 1
A paper feed roller 14 and a flat guide plate 15 that also serves as a platen are arranged behind the rack that can be engaged with the rack teeth No. 3. It is sent out from below and guided near the outside of the type belt 3. 17 is a selection lever for switching the output part of the planetary gear train 8 from the sun gear 43 to the link gear 42 and transmitting the rotational force of the link gear 42 to the printing carry gear 9 at a predetermined timing; Operated by solenoid 18.

Reference numeral 19 denotes a position detection section provided near the driven pulley 2, which detects a reference position for selecting printed characters and a printed character position. Reference numeral 20 denotes an ink roller that comes into contact with the type portion on the outer peripheral side of the type belt 3 to apply ink to the type surface.

The series of basic operations of this printer consists of a type selection operation, a print carry operation, a hammer holder return, and a paper feed operation, and by sequentially repeating each of these operations, many lines are printed. Ru. Each of the above-mentioned operations and related mechanisms will be explained in detail one by one, but first, the configuration of the type belt 3 will be explained.

[Composition of type belt]

As shown in FIG. 3, the type belt 3 has an endless shape, and a large number of type parts 21 are individually provided along the circumferential direction at predetermined pitches on the outer circumferential side.
A large number of belt teeth 22 are provided individually along the circumferential direction on the inner circumferential side, and a large number of belt teeth 22 are provided at predetermined pitches along the circumferential direction on the inner circumferential side. Individual type section 21
and the belt teeth 22 are provided in pairs, that is, at the same pitch, so that there is no space between the type portion 21 (belt tooth portion 22) and the adjacent type portion 21 (belt tooth portion 22). are connected to each other by a thin connecting portion 23. These type portions 21, belt tooth portions 22, and connecting portions 23 are made of, for example, synthetic rubber or synthetic resin with a low degree of polymerization, and the type belt 3 as a whole has appropriate flexibility, stretchability, and elasticity. .

As shown in FIG. 3, the total length of the type belt 3 is, for example, the first type group G1 and the second type group G
3 and a third type group G3. For example, the first type group G1 includes "+", "-", "x", "÷", memory symbol "M", total symbol "T", subtotal symbol "◇", mite count symbol "#", and various alphanumeric symbols. Or, it is a group that collects typefaces that are printed less frequently than numerical symbols such as other special symbols. On the other hand, the second type group G2 and the third type group G3 are groups that collect frequently printed type characters such as numerical symbols, and both groups each have one same type character, and the number of type characters is different from each other. The array order is the same. The details will be described later, but by arranging the characters on the character belt 3 as described above, the loss time for character selection can be reduced as much as possible.

The type part 21 and the belt tooth part 22 are not provided at the boundary between the type groups G1 and G3.
Instead, a push-down piece 24 is attached. The push-down piece 24 is made of relatively hard and slippery synthetic resin such as polyacetal resin, polyethylene resin, or polyamide resin, and has a substantially C-shaped side surface as shown in FIG. A notch 25 is formed in the middle for externally fitting onto the connecting portion 23 of the type belt 3. Note that the lower end of the push-down piece 24 protrudes slightly downward from the type section 21 and the belt tooth section 22 for a push-down function to be described later. On the other hand, as shown in FIG.
It is slightly recessed from the front surface, that is, the typeface, and when extruded by a hammer 66, which will be described later,
The push-down member 24 is designed not to come into contact with the paper 16.

The type belt 3 is made as follows. That is, as shown in FIG. 6, it has the same diameter as the type belt 3,
A wide cylindrical type belt 3a is made by molding, and is cut into a predetermined width dimension (height dimension of the type belt 3) to obtain a sliced type belt 3b. Then, the notch 25 (the fourth
The type belt 3 is completed by expanding and fitting the belt (see figure). Therefore, on the outer periphery of the type belt body 3a, type portions 21 having a predetermined character arrangement are repeatedly provided in the same arrangement in the width direction, while on the inner periphery, belt tooth portions 22 are provided in the width direction. It is formed into continuous ridges.

As explained in FIG. 1, the type belt 3 is stretched between the driving pulley 1 and the driven pulley 2,
Belt teeth 2 provided on the inner peripheral side of the type belt 3
2 mesh with the pulley teeth 26 (see FIG. 2) of the driving pulley 1 and the driven pulley 2, respectively, so that the type belt 3 is rotated reliably without slipping. Drive side pulley 1 as shown in the first
is rotated counterclockwise in the figure, and the type belt 3 is rotated in the direction of arrow A, and the tension side is between the driven pulley 2 and the driving pulley 1 on the side facing the paper 16. . Further, a code plate 28 (see FIG. 2), which will be described later, is attached to the pulley shaft 27 of the driven pulley 2.
Braking is always applied to the driven pulley 2 by making elastic contact with each contact piece 29 for detecting the position of printed characters. For this reason, paper 1 of type belt 3
There is no slack on the side facing the paper 16, and even if there is some vibration, the paper 16 will not swing significantly along the feeding direction. Therefore, the precision of the printing position when printing is high, and even if the distance between the type belt 3 and the paper 16 becomes narrower as printers become smaller, the type part 21 will not come into contact with the paper 16 unexpectedly.
Next, the type selection mechanism will be explained.

[Type selection mechanism]

First, the drive mechanism for the type belt 3 will be explained mainly with reference to FIG. The base 30 made of hard synthetic resin has a substantially rectangular planar shape, and a motor mounting recess 31 is provided at the center of the front side of the base 30, in which the DC motor 4 is installed. On the left side of the motor mounting recess 31, a pin-shaped gear support shaft 32 and a cylindrical gear support cylinder 33 are integrally protruded from the base at a predetermined interval.
A first idle gear 6 is rotatably fitted onto the gear support shaft 32, and a second idle gear 7 is rotatably fitted onto the gear support cylinder 33. The first idle gear 6 is provided with a helical portion 34 that meshes with the worm 5 attached to the DC motor 4, and a spur tooth portion 35 that meshes with the second idle gear 7. On the other hand, the second idle gear 7 has the spur tooth portion 3 of the first idle gear 6.
A spur tooth portion 36 that meshes with the tooth 5 is formed. Therefore, by fitting the first idle gear 6 to the gear support shaft 32 and the second idle gear 7 to the gear support cylinder 33, the worm 5, the first idle gear 6, and the second idle gear 7 can be connected to each other. are interlocked.

At the rear of the gear support cylinder 33, a pin-shaped main gear support shaft 38 and an ink roller support shaft 39 are respectively provided upright, and the main gear support shaft 38 has a planetary gear train 8 and a driving pulley 1. On the other hand, the ink rollers 20 are rotatably supported on the ink roller support shafts 39, respectively.

Here, the shape and structure of the planetary gear train 8 will be explained using FIGS. 7A and 7B and FIG. 8. 7A and 7B are exploded perspective views of the drive pulley 1 added to the gear train 8, as seen from diagonally below and diagonally above, respectively. FIG. 8 shows a schematic positional relationship of the planetary gear train 8. As shown in FIG. It consists of The support plate 40 has a spur tooth portion 40a that meshes with the spur tooth portion 36 of the second idle gear 7 along the axial direction, and a support shaft 4 at the center of the upper surface.
0b, three pin-shaped planet gear support shafts 40c are provided on concentric circles near the outer periphery of the upper surface and spaced at equal intervals. The tip 40d of the support shaft 40b is hexagonal, and the tip 40e is hexagonal. The planet gear 41 is connected to the support plate 40.
It is rotatably supported by a planet gear support shaft 40c. The ring gear 42 has a substantially cylindrical shape with a flange 42a, and a bevel tooth 42b that meshes with the print carry gear 9 on the flange 42a;
The upper part of the planet gear 41 has an outer peripheral part divided into five parts, five notches 42c, and a spur tooth part 42d that meshes with the outer part on the support plate 40 of the planet gear 41 along the axial direction on the inner wall surface of the collar part 42a. are doing. The sun gear 43 has a through hole 43a in the center whose diameter is slightly larger than the support shaft of the support plate 40, and its outer shape has a three-step shape in which the diameter decreases from the top. The planet gear 41 is parallel to the
A spur tooth portion 43b that engages with the inner side of the support plate 40 has five claw portions 43c on the outer periphery of the maximum diameter portion at positions that divide it into five parts. The support plate 4
After supporting three planet gears 41 on the shaft 40b and supporting the link gear 42 and sun gear 43 on the support shaft 40b, the driving pulley 1 is fitted and assembled. The through hole 1a at the center of the drive pulley 1 has a diameter slightly larger at the lower part than the diameter of the support shaft 40b, and a hexagonal upper part so as to fit with the tip 40d of the support shaft 40b. . As mentioned above, in this planetary gear train 8, the spur tooth portion 42d of the ring gear 42 meshes with the outer portion of the planet gear 41, and the spur tooth portion 43b of the sun gear 43 meshes with the inner portion of the planet gear 41 (see Fig. 8). Accordingly, the support plate 4
0 is the input part, link gear 42, sun gear 43
is used as an output section, and switching thereof is performed by a selection lever 17 and an electromagnetic solenoid 18, as will be described later.

By fitting the planetary gear train 8 onto the main gear support shaft 38, the support plate 40 and the second idle gear mesh, and the rotational driving force of the DC motor 4 is
Via the worm 5, the first idle gear 6, and the second idle gear 7, the support plate 40 is transmitted to be rotationally driven in a constant direction, that is, in the counterclockwise direction in FIG. 1, at a constant speed. .

The rotational driving force of the support plate 40 is directly transmitted to the drive pulley 1 fitted into the support plate 40, so the drive pulley 1 always rotates in conjunction with the support plate 40, and as a result, the type is rotated. Belt 3 also rotates.

In order to select type, it is first necessary to detect the reference position of the type belt 3. Next, a mechanism for detecting this reference position will be described. As explained in FIG. 1, the position detection section 19 is provided near the driven pulley 2. As shown in FIG. 2, this position detection section 19 includes a spherical button 51 and an elastic metal piece 52.
It is mainly composed of a code plate 28 and a contact piece block 53. The button 51 is made of metal or hard synthetic resin, and is shown in FIGS.
As shown in Figure 0, the pulley shaft 27 of the driven pulley 2
is inserted into a buttonhole 55 provided on the movement trajectory of the type belt 3 near the shaft hole 54 into which it is inserted. Since the tip of the elastic metal piece 52 is disposed below the button hole 55, the button 51 is supported by the elastic metal piece 52, and as shown in FIG. It protrudes slightly from the top surface. The base end of the elastic metal piece 52 is bent vertically upward to form a metal piece terminal 56.
It penetrates from below to above the terminal array groove 57 formed in the base 30, as shown by the dotted line.

The pulley shaft 27 of the driven pulley 2 is tightly fitted into the center hole of the code plate 28, so that the code plate 28 rotates together with the driven pulley 2.
Although not shown, a conductive pattern having a predetermined shape is formed on the lower surface of the code plate 28 to detect the rotation angle of the driven pulley 2, in other words, the amount of movement of the type belt 3. The conductive pattern is formed, for example, by printing or by bonding thin metal pieces. The contact piece block 53 is composed of a reset contact piece 58, a bifurcated common contact piece 59, a set contact piece 60, and a mounting plate 61 to which these are attached by insert molding or the like. The base end of each contact piece 58, 59, 60 is bent vertically upward to connect a reset terminal 62, a common terminal 63, and a set terminal 6.
4, and protrudes upward from the terminal arrangement groove 57 in line with the metal piece terminal 56 as shown by the dotted line. Although not shown, each terminal 56, 62, 63, 64 is connected to the control section by a lead wire.

The tips of the reset contact piece 58, the shorter common contact piece 59, and the set contact piece 60 are in elastic contact with the lower surface of the code plate 28, and the longer common contact piece 59 is connected to the elastic metal piece as shown in FIG. 52 and are opposed to each other at a predetermined interval.

As the drive pulley 1 rotates, the type belt 3 rotates in the direction of arrow A (see Figures 1 and 3), and the push-down piece 24 attached to the type belt 3 does not pass over the button 51. As shown in FIG. 9, the button 51 is supported by an elastic metal piece 52 and slightly protrudes from the base 30.
and the common contact piece 59 are separated. When the type belt 3 further rotates and the push-down piece 24 comes above the button 51, the upper surface of the push-down piece 24 comes into contact with the outer flange 65 of the driven pulley 2, and as a result, the first
As shown in Figure 0, the button 51 is pressed down against the elasticity of the elastic metal piece 52;
contacts the common contact piece 59. This contact causes
The metal piece terminal 56 and the common terminal 59 are instantaneously electrically connected, and based on the signal, it is possible to detect that the type belt 3 is currently at the reference position.

When the type belt 3 is at the standard position, the hammer 6
Since the distance of each type part 21 from the type part 21 (or push-down piece 24) facing the type part 6 is known in advance, the amount of movement of the type belt 3, in other words, the driven pulley 2, is determined after the reference position is detected. By electrically counting signals of the rotation angle of
The type belt 3 can be rotated to a position opposite to the type belt 6.

Changes in the amount of movement of the type belt 3 due to carrying will be explained in detail with reference to FIGS. 11A and 11B.
A in the same figure is an explanatory view showing changes in the amount of movement of the type belt mentioned above, and B in the same figure is a partial front view of the paper 16 printed by this specific example.

First, the amount of movement of the type belt 3 when the hammer 66 is at the lowest digit as shown by the solid line will be described. The printing start signal causes the type belt 3 to rotate in a predetermined direction, and as shown in FIG. Assume that the reference position has been detected. At this time, the amount of movement l ₁ from the type part 21s facing the hammer 66 to the type part 21 of the symbol "+" to be printed at the lowest digit
is processed by the control unit, and the position detection unit 19 counts until the type belt 3 moves l ₁ , and the symbol “+” is detected.
The hammer 66 starts to be driven just before the type portion 21 having the character faces the hammer 66, and when the hammer 66 hits the type belt 3, printing is performed at a timing such that it is "+". This method of printing by constantly rotating the type belt is generally called a flying method. The symbol printing operation ends at the lowest digit, and the numerical value is subsequently printed, but as shown in Figure 11 (b), the symbol digit 6
If 7 and the numerical digit 68 are separated by one digit, the symbol digit 67 and the numerical digit 68 can be clearly distinguished and are very easy to see. Therefore, after printing the lowest digit, the next higher digit is not printed (details will be described later), and the hammer 66 is moved to the higher digit as shown by the dotted line in Figure 11A. . Therefore, when it is desired to print the numerical value "3" next, the first character group G1 is printed in the rotating direction of the character belt 3.
The printed character portion 21 with the numerical symbol "3" is selected from the second printed character group G2 which is closest to (requires the least amount of movement of the printed character belt 3). The printing section 21 that was facing the hammer 66 when detecting the reference position
The control unit calculates a movement amount l ₂ which is the sum of the distance from s to the type part 21 selected in the second type group G2 and the distance traveled by the hammer 66 by two digits from the lowest digit. Then, the position detection unit 19 detects the type belt 3.
The driving timing of the hammer 66 is calculated, and the hammer 66 is driven so that the amount of movement of the hammer 66 is counted and the printing is performed when the character part 21 of the numerical symbol "3" faces the hammer 66.

Furthermore, when it is desired to print the numerical value "3" next, the printed character section 21 of the numerical symbol "3" is selected from the third printed character group G3 closest to the second printed character group G2. Then, from the printing section 21s that was facing the hammer 66 at the time of detecting the reference position, the third printing group G
The distance to the type part 21 selected in step 3 and the hammer 6
The moving amount _l3 , which is the sum of the distance traveled by one digit of 6, is calculated in the same way, and based on the calculation result, the moving amount of the type belt 3 is counted, and at the same time, the driving timing of the hammer 66 is calculated. A printing operation is performed. In this way, until printing for one digit is completed, the movement amount l of the type belt 3 is adjusted for each type selection based on the position of the printing part 21s that was facing the hammer 66 when the reference position was detected. The hammer drive is performed by calculating the timing (calculating the time from the start of driving the hammer 66 to hitting the type belt 3), but in reality, the type selected by the previous lower digit Since the amount of movement ln up to the part 21 has already been calculated, the amount of momentum of the next digit and the driving timing of the hammer 66 are calculated by adding it thereto.

FIGS. 12 and 13 are diagrams showing other examples of the reference position detection means. In the reference position detection means shown in FIG. 12, when the type belt 3 is molded, a conductive movable contact portion 69 for detecting the reference position is integrally formed of conductive rubber or conductive synthetic resin. This movable contact portion 69 protrudes slightly downward from the type portion 21, the belt tooth portion 22, etc., and is provided under the rotation locus of the movable contact portion 69 so as to come into contact with two fixed contact pieces 70a, 70b. ing.
Therefore, when the conductive movable contact portion 69 passes over the fixed contact pieces 70a and 70b as the type belt 3 rotates, both the contact pieces 70a and 70b are electrically connected, thereby causing the type belt 3 to The reference position can be detected.

In the reference position detection means shown in FIG. 13, a conductive movable contact portion 69 for detecting the reference position is made of a metal piece, and is attached to a predetermined position on the type belt 3 by caulking. Similar to the reference position detection means described in FIG. 13, a movable contact portion 69 protrudes slightly downward from the type portion 21 and the belt tooth portion 22, and fixed contact pieces 70a arranged at intervals,
It is now possible to contact 70b.

In addition, a reflective or transmissive photo sensor may be provided near the type belt 3 to optically detect the reference position and/or the amount of movement of the type belt 3. Next, the print carry mechanism will be described.

[Print carry mechanism]

As shown in FIG. 2, a solenoid mounting base 71 is protruded from the left side of the motor mounting recess 31 on the front side of the base 30, and the electromagnetic solenoid 18 is fixed by the mounting base 71 via a mounting piece 72. be done.
The actuator 73 of the electromagnetic solenoid 18 has an L-shaped planar shape, and a through hole 74 is formed in a horizontal portion provided between a base end 73a and a free end 73b. On the other hand, an actuator support shaft 75 is located next to the gear support cylinder 33 of the base 30.
is provided protrudingly, and its upper small diameter portion is inserted into the through hole 74, and the actuator 73 is attached to this support shaft 7.
It is designed to rotate by a predetermined angle about 5. The lower large diameter portion of the actuator support shaft 75 includes
An actuator biasing spring 76 is loosely fitted, one end 76a of which is loosely fitted to the edge of the base 30 as shown by the dotted line, and the other end 76b of which is loosely fitted to the actuator 73 as shown by the dotted line.
are respectively locked at the base ends 73a.

As shown in FIG. 2, a lever rotation shaft 77 extends below the selection lever 17, and the rotation shaft 77 is fitted into the central recess of the gear support cylinder 33. This selection lever 17 has a first claw portion 5 that engages with the claw portion 43c of the sun gear 43 of the planetary gear train 8.
0, a second claw portion 78 that engages with the notch 42c of the ring gear 42, and a vertical engagement groove 79 into which the free end 73b of the actuator 73 is inserted with some clearance are provided. ing.

Next, regarding the shape of the print carry gear 9, the 14th
This will be explained using FIGS. 16 to 16. Figure 14 shows
A front view of the printing carry gear 9, FIG. 15 is a partially cutaway right side view thereof, and FIG. 16 is a rear view thereof. The print carry gear 9 is provided with a front toothed portion 80 in its axial direction.
is adapted to mesh with the bevel tooth portion 42b of the ring gear 42 of the planetary gear train 8. A shaft hole 84 having an oval-shaped front face is formed in the center along the axial direction, and one end of the print carry shaft 10 having an oval-shaped cross section is tightly fitted into the shaft hole 84 . As shown in FIGS. 2 and 15, a circumferential groove 85 is formed on the rear outer periphery of the printing carry gear 9. This circumferential groove 85 is fitted into a bearing 86 provided on the base 30, and the printing is carried out. By inserting the other end of the carry shaft 10 into the bearing 87, the print carry shaft 10 is rotatably supported on the base 30.

This print carry gear 9 meshes with the bevel tooth portion 4 of the ring gear 42 of the planetary gear train 8.

Next, support plate 40 of planetary gear train 8 → sun gear 43
The switching of the drive transmission from the support plate 40 to the print carry shaft 10 will be explained. FIG. 18 shows a state in which drive is transmitted from the support plate 40 to the sun gear 43. That is, in this state, since the electromagnetic solenoid 18 is not energized, the base end 73a of the actuator 73 is pulled by the actuator biasing spring 76 as shown in FIG. As a result, the actuator 73 rotates clockwise around the actuator support shaft 75, and its free end 73b presses the engagement groove 79 of the selection lever 17 toward the front in the drawing. . Due to this pressing, the selection lever 17 is rotated counterclockwise about the lever rotation shaft 77, and as shown in FIG.
On the other hand, the first claw portion 50 is separated from the claw portion 43c of the sun gear 43. Therefore, the rotational force transmitted from the motor 4 to the support plate 40 via the first idle gear 6 and the second idle gear 7 is transmitted to the drive side pulley 1 and sun gear 43, which are directly fitted into the support plate 40, and Side pulley 1 and sun gear 43
rotates in the same direction as the support plate 40. Therefore, the type belt 3 moves and detects the reference position as described above.
and print selection based on it. Furthermore, the rotational force of the sun gear 43 is only used as a dummy in this embodiment.

In order to select a specified type part 21, a command is issued from the control unit, and based on the command, the electromagnetic solenoid 1 is activated.
8 is energized and excited. With this excitation, the base end 73a side of the actuator 73 is attracted to the electromagnetic solenoid 18 against the elasticity of the actuator biasing spring 76, as shown in FIG. 17 rotate clockwise. This rotational movement causes the second claw portion 78 of the selection lever 17 to move toward the ring gear 42.
apart from the notch portion 42c, and instead of the first claw portion 5.
0 engages with the claw portion 43c of the sun gear 43. This prevents the sun gear 42 from rotating, and the rotational force of the support plate 40 is transmitted to the drive pulley 1 and the ring gear 42. Therefore, the print carry gear 9 that meshes with the deformed umbrella portion 42b of the ring gear 42
rotates, is transmitted to the print carry shaft 10 via the print carry gear 9, and rotates in the direction of arrow C.

As shown in FIGS. 2 and 20, the hammer holder 11, which is slidably attached to the print/carry shaft 10, has insertion holes 91, 91 on both rear side plates through which the print carry shaft 10 can freely rotate. formed,
A hammer rest 92 extends horizontally from the rear to the front on the upper inner side thereof. A spring hanging pin 93 is protruded from the rear of one of the side plates, and a long groove 94 is cut horizontally in the direction of the spring hanging pin 93 in front of the spring hanging pin 93. Lever support portions 95 cut in the shape of a lever are formed on both side plates diagonally below and in front of the long groove 94, and a partition wall portion 96 is suspended in front of the hammer holder 11. As shown in FIG. 21, this partition wall portion 96 has a protrusion opening 97 in the middle thereof large enough to allow one of the selected type portions 21 to protrude, and the partition wall portion 96 is provided on both sides of the protrusion opening 97. As shown in FIG. 22, if a taper 98 is provided on the inner side of the partition wall 96 at the end closer to the ejection opening 97, the type portion 21 can be smoothly projected from the ejection opening 97.

A carry paper feed cam that is spline-coupled to the print carry shaft 10 is built in below the hammer placement portion 92 of the hammer holder 11 . As shown in FIGS. 23 to 25, this cam has a hammer drive section 1010 extending in one direction from the center toward the outer periphery.
, a carry cam part 102 having a single protrusion 101 on the outer periphery, and an oval rack rotation part 103 for returning the rack 13 for paper feeding,
These are integrally formed by molding synthetic resin. FIG. 26 is a developed view of the cam surface of the carry cam portion 103, in which the protrusion 101 includes a circumferential protrusion 101a extending in the circumferential direction and a circumferential protrusion 101a provided over approximately half of the circumferential direction; A helical protrusion 101 extending in a helical manner and extending over approximately half of the area.
b, and these protrusions 101a and 101
b is continuous. This protrusion 101 is
Rack teeth 1 provided at equal intervals on one side of 3
It is designed to mesh with 04.

The hammer 66 is placed on the hammer mounting portion 92 with the extrusion portion 105 facing the partition wall portion 96, and the convex portion 106 projecting upward is slidably fitted into a guide groove 107 formed on the upper surface of the hammer holder 11. ing. A spring hook pin 108 projects outward from the long groove 94 of the hammer holder 11 on one side of the hammer 66 . And the spring hook pin 93 of the hammer holder 11 and the spring hook pin 10 of the hammer 66.
A tension spring 109 is stretched between the type belt 8 and the hammer 66, and its tension elastically biases the hammer 66 in a direction away from the type belt 3 (backward). A receiving portion 110 is provided below the spring hook pin 108, with which the hammer drive portion 100 of the carry paper feed cam 99 comes into contact with rotation.

27 and 28 are diagrams for explaining the printing operation, and FIG. 27 shows the state before printing in the second
FIG. 8 is a diagram showing the printed state. In the state before printing, as shown in FIG. 27, the hammer 66 is pulled rearward by the tension spring 109, and is positioned by a stopper (not shown). Therefore, the type belt 3 (type part 2
1) is located between the partition wall portion 96 of the hammer holder 11 and the extrusion portion 105 of the hammer 66;
It is a little far from 5. Also, the hammer drive unit 100
faces downward and is in contact with the receiving portion 110 of the hammer 66.

The print carry shaft 10 rotates once in the direction of arrow C due to drive transmission from the ring gear 42.
The printing operation is performed continuously during the first half of the cycle, and the carry operation is performed continuously during the second half of the cycle. That is, when the print carry shaft 10 rotates in the direction of arrow C, the carry paper feed cam 99 spline-coupled to it also rotates together, but the circumferential protrusion 101a engages with the easy tooth portion 104 on the previous half circumference. Since they are aligned, the carrying paper feed cam 99 (along with the hammer holder 11, hammer 66, etc.) is not moved, but only makes half a turn on the spot. Halfway around this carry paper feed cam 99, the hammer drive unit 100 moves to the 28th position.
As shown in the figure, the hammer 66 comes into contact with the receiving part 110, and the hammer 66 is pushed forward against the elasticity of the tension spring 109 by the subsequent rotation of the hammer driving part 100. The selected character portion 21 facing the paper 16 is pushed forward by the hammer 66 through its ejection opening 97 and is pressed against the paper 16 to form a desired print. Note that, as shown in FIG. 21, since partition wall portions 96 are provided on both sides of the projection opening 97, unnecessary printing such as side printing is not performed. As the print carry cam 99 rotates, the hammer drive unit 100
As shown in FIG. 28, by moving the hammer 66 upward from the horizontal position, the tension spring 109
The hammer 66 is pulled backward by the type belt 3, and the hammer 66 is separated from the type belt 3. When the hammer 66 reciprocates, the hammer mounting portion 92, the convex portion 106 and the guide groove 1
07 and the spring hook pin 108 and the long groove 94, the hammer 66 is properly guided.

When the print carry cam 99 continues to rotate,
This time, the above-mentioned spiral protrusion 101b is connected to the easy tooth 10.
4, and as it rotates, the hammer holder 11, hammer 66, print carry cam 99, etc. move toward the upper digit (to the left in Fig. 1) by an amount corresponding to one digit against the elasticity of the hammer return spring 12, and the carry is increased. will be done.

By repeating such character selection, printing operation, and carry operation, one line is printed.

In FIG. 2, a rack receiving through hole 111 is bored diagonally below the bearing 86, and a rack 1 is inserted therein.
A columnar portion 112 at one end of the rack 13 is rotatably inserted, and a columnar portion at the other end of the rack 13 is rotatably fitted into an arc-shaped rack receiving recess 114 provided diagonally below the bearing 87. positioning is performed. On the back side of the rack receiving through hole 111 and the rack receiving recess, there is an arm 116 that rotatably supports both ends of the paper feed shaft 115 at the bottom.
A paper guide wall 11 with two paper guide walls provided at a predetermined interval.
7 are erected.

FIGS. 29A and 29B are a partial front view showing the shape of the upper part of the paper guide wall 117 and a partial front view of the paper printed according to the embodiment. As mentioned above, if the symbol digit 67 on the lower digit side and the numerical digit 68 on the upper digit side are separated by a predetermined distance, for example, one digit, the symbol digit 67 and the numerical digit 68 can be distinguished. It's clear and very easy to read. Therefore, on the upper part of the paper guide wall 117, there is a printing notch 118 for printing in a place corresponding to the symbol digit 67 and a printing notch 119 for printing in a place corresponding to the numerical digit. , a mask portion 120 having a width equivalent to one digit is provided. Then, while the hammer is moving from the symbol digit 67, which is the lowest digit, to the numerical digit 68, which is the higher digit, the mask portion 12
0, and the same operation as a normal printing operation is performed, but the printing part 21 pushed out by the hammer 66 comes into contact with the mask part 120, so no printing is done on the paper 16. . Therefore, when selecting a type at this digit position, the type portion 21 slightly before the type portion 21 selected at the next higher digit is selected. Next, the hammer holder return paper feeding mechanism will be explained.

[Hammer holder return paper feed mechanism]

As mentioned above, once one line has been printed,
It is necessary to return the hammer holder 11 to its home position again to prepare for printing the next line. Although the explanation was omitted in the above [Print carry mechanism] section,
Lever support portions 95, 95 of the hammer holder 11
Both ends of the lock release lever 121 are rotatably supported. This release lever 121
is provided with a receiving claw 122 that projects upward and a slide protrusion 123 that projects downward. As shown in FIGS. 30 and 31, the rack release lever 121 is disposed between the hammer 66 and the rack 13, and before the rack 13 is rotated, the receiving pawl 122 is As shown in the figure, it is located diagonally in front of the lower part of the type belt 3. On the other hand, the sliding protrusion 123
The slide protrusion 123 is inserted into a hook groove 124 formed along the longitudinal direction on the upper surface of the hammer holder 11, and as the hammer holder 11 is transferred, the slide protrusion 123 slides within the hook groove 124.

FIG. 30 shows the state before starting the hammer holder return. In this state, the position of the push-down piece 24 is selected so as to face the hammer 66, and since the push-down piece 24 protrudes below the type belt 3, the upper end of the receiving claw 122 It is located slightly above the lower end of 24.
As in a normal printing operation, the hammer driving section 100 rotates in the direction of arrow C, thereby pushing the push-down piece 24 toward the paper 16 via the hammer 66. As the push-down piece 24 moves horizontally, the rack release lever 121 rotates in the direction of arrow D as shown in FIG. Since they are engaged, the rack 13 is rotated in the direction of arrow E as the rack release lever 121 is rotated. The rack 13, which has been tilted in the direction of the arrow E in this manner, remains in the tilted state until it is rotated back to its original position by a rack rotating section 103, which will be described later. Then, the rack tooth 104 separates from the protrusion 101 of the print carry cam 99, and the engagement between the rack 13 and the print carry cam 99 is released. Then, the hammer holder 1 containing the hammer 66, print carry cam 99, and lock release lever 121 is released.
1 is returned to the home position side along the print carry shaft 10 by the tensile force of the holder return spring 12.

As shown in FIG. 2, at the right end of the rack 13, there are two chevron-shaped paper feed intermediate lever portions 125 that have a step along the axial direction of the rack 13.
is installed protrudingly. On the other hand, as shown in FIGS. 2, 24, and 25, the carry and paper feed cams 99
A substantially disc-shaped intermediate stopper part 126 is integrally provided on the end face of the rack rotating part 103, and a paper feed intermediate lever part 125 of the rack 13 is disposed at a predetermined position of the stopper part 126, as shown in FIG. A fan-shaped cutout 127 is formed with a size that allows the insertion of the fan. Therefore, when the hammer holder 11 returns to the home position side, the paper feed intermediate lever portion 12
The side end surface of the rack tooth 104 of No. 5 and the intermediate stopper portion 1
The hammer holder 11 comes into contact with the outer surface of the hammer holder 26, and the movement of the hammer holder 11 is stopped. In this way, since the hammer holder 11 is stopped at an intermediate position close to the home position, the rack rotating portion 103 of the carry paper feed cam 99 and the paper feed intermediate lever portion 125 of the rack 13 are at positions shifted from each other. They are not facing each other.

A paper feeding operation is performed in parallel with this hammer holder return operation, and this operation will be explained next. As shown in FIG. 2, an engagement pin 128 is provided on the opposite side of the rack 13 from the rack teeth 104 and projects in parallel to the axial direction of the rack 13. Behind this rack 13,
A paper feed shaft 115 is arranged parallel to this, and a paper feed roller 14 having two rubber rings 129 elastically fitted thereon at a predetermined interval is fixed to approximately the left half of the shaft. As shown in FIGS. 2 and 32, a driven paper feed latch 130 is attached to the right end surface of the paper feed roller 14, and a drive side paper feed latch 131 rotatably supported on the paper feed shaft 115. They are facing each other. As shown in FIG. 32, the drive side paper feed latch 131 is always urged in the direction of engagement with the driven side paper feed latch 130 by the elasticity of a ratchet biasing spring 132 inserted between it and one arm 116. ing. As shown in FIG. 2, FIG. 33, and FIG.
Pin groove 1 into which 28 is rotatably fitted while lying down
33 are provided. Further, as shown in FIG. 34, a driven roller 134 is disposed diagonally above the paper feed roller 14 and rotates with the paper feed roller 14.
6 is held between the paper feed roller 14 and the driven roller 134.

FIG. 33 shows the state before paper feeding is started. In this state, character selection or print carry operation is being performed, and the rack 13 and carry paper feed cam 99 are engaged.

As mentioned above, the third
When the rack 13 rotates in the direction of the arrow E as shown by the solid line in FIG. As in, arrow F
direction by a predetermined angle. In this rotation in the direction of arrow F, the driving side paper feed latch 131 and the driven side paper feed latch 130 have tooth shapes that do not mesh with each other, so that when the rack 13 is completely fallen down, as shown in FIG. The pin groove 133 of the drive-side paper feed ratchet 131 is stopped with the pin groove 133 facing slightly upward, and is in a standby state for paper feeding.

On the other hand, when the rack 13 rotates, the engagement between the rack teeth 104 of the rack 13 and the carrying paper feed cam 99 is disengaged, so that the holder return spring 12 described above
With this tensile force, the hammer holder 11 quickly returns to its home position. Note that when the hammer holder 11 returns to the home position from the lower digit, the hammer holder 11 reaches near the home position during the remaining 3/4 rotation of the carry paper feed cam 99; During the rotation of the feed cam 99, the intermediate stopper portion 126 of the carry paper feed cam 99 comes into contact with the side surface of the paper feed intermediate lever portion 125 of the rack 13, and the rack rotating portion 103
Since the paper feed intermediate lever section 125 and the paper feed intermediate lever section 125 are shifted in position, the rack rotation section 103 moves the rack 1
3 is not scraped up, therefore, the fallen state of the rack 13 and the standby state of the drive-side paper feed ratchet 131 shown in FIG. 34 are maintained as they are. When the carrying paper feed cam 99 completes one rotation, the fan-shaped cutout portion 127 of the intermediate stopper portion 126 is inserted into the paper feed intermediate lever portion 125 of the rack 13.
At this time, the hammer holder 11 can completely return to the home position.

As mentioned above, when the print carry shaft 10 completes one rotation to return the hammer holder (at this time, the electromagnetic solenoid 18 is already in the de-energized state), the selection lever is activated as shown in FIG. 17A. 1
The second claw portion 78 of No. 7 falls into the notch portion 42c of the ring gear 42 of the floating gear train 8 due to the tensile force of the actuator biasing spring, thereby causing the ring gear 4
2 and the rotation of the print carry gear 9 (print carry shaft 10) are prevented, resulting in a stationary state. At this time, the type belt is always rotating, but even during this rotation of the type belt 3, the rack teeth 104 of the rack 13 and the carrying paper feed cam 99 are disengaged, so that the above-mentioned This will allow enough time for the hammer holder to return. Next, the position of the type belt 3 is selected so that the push-down piece 24 faces the hammer 66, and the push-down piece 24
is located opposite the hammer 66, and the electromagnetic solenoid 1
8 is excited, and the print carry shaft 10 is activated in the same manner as described above.
28, the push-down piece 24 is pushed out by the hammer 66 as shown in FIG. The difference from the hammer holder return operation is that the rack 13 has fallen and the drive-side paper feed ratchet 131 is in a paper feed standby state, so the push-down piece simply moves back and forth. On the other hand, at this time, the hammer holder 11 is moved by the tensile force of the holder return spring 12 and has completely returned to the home position. 125, and as the carry paper feed cam 99 continues to rotate, the easy rotation part 103 abuts on the paper feed intermediate lever part 125, and the paper feed intermediate lever part 12
5, the rack 13 which has fallen down is rotated in the direction of arrow G as shown by the dotted line in FIG. With this rotation, the rack 13 returns to its original position, and the rack tooth 104
engages with the protrusion 101 of the carrying paper feed cam 99, and the driving side paper feed latch 131 rotates in the direction of arrow H as the rack 13 rotates. When rotating in the direction of arrow H, the driving side paper feed latch 131 and the driven side paper feed latch 13
Because the tooth shape is such that 0 and 0 mesh with each other,
Paper feed roller 14 similarly rotates in the direction of arrow H, thereby pushing out paper 16 in the direction of arrow I, thereby feeding the paper by an amount equivalent to half a line.

When the carrying paper feed cam 99 rotates once, the transmission of the driving force is switched by the selection lever 17, and the position is selected so that the push-down piece 24 of the rotating type belt 3 faces the hammer 66. Ru. While the carry paper feed cam 99 rotates once, the rack 13 reciprocates in the directions of arrows E and G as shown in FIG. 14)
By rotating in the direction of arrow F, the paper enters a paper feeding standby state, and by continuing to rotate in the direction of arrow H, the paper 16 is pushed out in the direction of arrow I, and the paper is not fed by an amount equivalent to the remaining half line. be done.

In this embodiment, by rotating the paper feed roller 14 twice, the paper is fed by an amount equivalent to one line. It is also possible to feed paper by a corresponding amount.

As shown in FIG. 34, the paper 16 is sent out by the cooperation of the paper feed roller 14 and the driven roller 134.
For example, as shown in FIG. 27, the guide plate 15
The area to be printed next is pushed up through the gap between the paper guide wall 117 and the hammer 66 so as to face the hammer 66. As mentioned above, the paper guide wall 117 is formed integrally with the base 30, but the guide plate 15 has guide plate support recesses 135, 13 formed at the upper rear of both ends of the paper guide wall 117, as shown in FIG.
5, both ends of which are tightly fitted to each other, so that it is fixed so that it does not wobble. This guide plate 1
5 is made of a thick metal plate and also serves as a platen.

As mentioned above, in this printer, the type selection operation begins after the return of the hammer holder 11 is started until the fallen rack 13 is lifted up. If you have enough time and the hammer holder 11 (carry paper feed cam 99) does not return to the home position completely, it will be easy 13.
Since the mechanism is such that the rack 13 cannot be rotated to the position where it can be carried, the rack 13 rotates while the hammer holder 11 is returning, and the rack 13 is moved to the halfway position.
There is no possibility that the return operation of the hammer holder 11 will be prevented due to engagement between the carry paper feed cam 99 and the carry paper feed cam 99.

(c) Effect The present invention has the following effects.

Since the printer according to the present invention performs printing using a flying method, very high-speed printing is possible, and since the type belt 3 does not suddenly stop or start moving during printing, it is possible to print at a very high speed. The vibration of the type belt 3 is extremely reduced, and the paper is not stained by the vibration of the type belt 3, resulting in clean printing.

In addition, in the case of the flying method, the position of the type and the timing of hammering are important, but when a planetary gear train is used as in the present invention, the pulley and the hammer drive shaft are always connected with the gears, so there is a constant Since the positional relationship is stable, accurate printing without printing errors can be obtained, and reliability is significantly improved.

[Brief explanation of drawings]

The figures are all for explaining the printer according to the embodiment of the present invention, and FIG. 1 is a schematic configuration diagram seen from a plane of the printer, FIG. 2 is an exploded perspective view of the printer, and FIG. 3 is a plane view of a type belt. 4 is a partially enlarged perspective view of the type belt, FIG. 5 is a partially enlarged plan view of the type belt, and FIG. 6 is a plan explanatory view for explaining how to make the type belt. 7
Figures A and B are exploded perspective views showing the configuration of the planetary gear train.
Figure 8 is a schematic explanatory diagram showing the positional relationship of each part of the planetary gear train, Figures 9 and 10 are enlarged sectional views of the reference position detection section, and Figure 11A is a change in the amount of movement of the type belt due to carry. An explanatory diagram showing the figure, B is a front view of a portion of the paper printed according to a specific example,
12 and 13 are partially enlarged perspective views showing other examples of the reference position detection means, FIG. 14 is a front view of the print carry gear, and FIG. 15 is a partially cut away right side view thereof. , FIG. 16 is a rear view thereof, FIG. 17 is an explanatory diagram showing the arrangement of the print carry gear, and FIG.
19 are explanatory diagrams showing the operation of the selection lever, FIG. 20 is a perspective view of the hammer holder, FIG. 21 is a partial front view of the hammer holder, FIG. 22 is an enlarged cutaway plan view of the partition wall of the hammer holder, and FIG. 23
The figure is a front view of the carry cam part, Fig. 24 is a side view of it, Fig. 25 is a rear view of it, Fig. 26 is a developed view of the cam surface, and Figs. 27 and 28 show the printing operation. 29A is a side view of the printing unit for explanation, FIG. 29B is a partial front view of the paper guide wall, FIG.
31 and 31 are side views of the main parts for explaining the rotating operation of the rack, FIG. 32 is a plan view of the main parts of the paper feeding section, and FIGS. 33 and 34 are explanatory views showing the paper feeding operation. be. 1... Drive side pulley, 2... Driven side pulley, 3... Type belt, 4... DC motor, 8... Planetary gear train, 9
...Print carry gear, 10...Print carry shaft, 11...
Hammer holder, 13...Rack, 14...Paper feed roller, 15...Guide plate, 16...Paper, 17...Selection lever, 18...Electromagnetic solenoid, 19...Position detection section, 21...Print section, 24...Press down piece, 28 ... code plate, 29 ... contact piece, 40 ... support plate, 41 ... planet gear, 42 ... ring gear, 43 ... sun gear, 50 ... first claw part, 51 ... button, 52 ... elastic metal piece, 53 ... contact piece block, 66...Hammer, 6
7... Symbol digit, 68... Numerical digit, 69... Movable contact part,
70... Fixed contact piece, 73... Actuator, 78... Second claw part, 96... Partition wall part, 97... Projection opening, 99... Carry paper feed cam, 100... Hammer drive part, 101
... Projection, 102... Carry cam part, 103... Rack rotation part, 104... Rack tooth, 115... Paper feed shaft,
117... Paper guide wall, 118... Printing notch, 1
20...Mask part, 121...Rack release lever, 1
22... Receiving claw, 125... Paper feed intermediate lever portion, 12
6... Intermediate stopper part, 128... Engagement pin, 13
0... Driven side paper feed ratchet, 131... Driving side paper feed ratchet, 134... Driven roller.

Claims (1)

[Claims] 1. An endless belt-shaped type carrier having a large number of type parts arranged side by side on the outside, a type carrier rotating means for rotating the type carrier, a supplying means for supplying paper to the outside of the endless belt-shaped type carrier, and a hammer means that is conveyed inside the endless belt type type carrier in a direction perpendicular to the feeding direction of the paper and presses selected type portions onto the paper; a planetary gear train; One drive source that constantly rotates the endless belt-shaped type carrier by constantly rotating a rotation means and an output section of the planetary gear train are switched to selectively drive the hammer means at a desired type position. and trigger means for moving the hammer means in the digit direction, and the type carrier rotating means and the hammer means are gear-coupled via the planetary gear train.