JPH0558901B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a type serial printer, and particularly to a type serial printer capable of alphanumeric printing.

<Prior Art> Conventional type serial printers of this type generally select characters by vertically shifting and rotating the type cylinder. In this case, the carriage becomes large due to the large height and travel distance of the type cylinder, and the shift selection mechanism and character selection mechanism use a complex mechanism that combines multiple electromagnets, clutches, cams, and levers. Since the control method was also complicated, it was difficult to realize a small and inexpensive type serial printer.

Although the serial printer proposed in JP-A-57-109677 has improved the above-mentioned drawbacks, as shown in FIG. The drive force for shift selection is transmitted to the shift cam 7 in the carriage by the shift cam shaft 40, and the detector 46 is required to detect the shift position of the type wheel group. It could not be called a simple mechanism.

In addition, in a serial printer proposed in Japanese Patent Application Laid-Open No. 57-173188, an independent step motor drives a hammer and a group of type wheels, which face each other while holding printing paper between them, to compensate for the difference in the amount of transport in each digit direction. Therefore, shift selection is performed, but since an expensive mechanical part called a step motor and a transmission mechanism using wires are required for shift selection, there is a problem in terms of price. Furthermore, the control method for driving two independent step motors is also complicated.
Since the step motor itself is generally not an efficient power source, it has been difficult to reduce current consumption, especially when driving it with a battery.

<Object of the Invention> The present invention has been made in view of these drawbacks, and its object is to provide a compact, low-cost type serial printer capable of alphanumeric printing.

Another object of the present invention is to reduce the current consumption of the printer mechanism and to provide a portable type serial printer powered by batteries.

<Characteristics of the Invention> In order to solve the above problems, the type serial printer of the present invention includes a carriage that is held slidably in the digit direction, and a carriage that is rotatably and slidably mounted on the digit direction. A type ring group formed of a plurality of flexible type wheels on which type is arranged, a printing means mounted on a carriage for printing by pushing out the type from the inside of the type ring, and a printing means mounted on a carriage and formed of a plurality of flexible type wheels. A DC motor is a drive source for the drive and hammer, a type selection means for controlling the rotation of the type wheel group, a switching means for switching the power of the DC motor to either the printing means or the type selection means, and a type selection means for controlling the rotation of the type wheel group. A shift selection means for shifting the carriage, a spacing means for moving the carriage in the digit direction, a detection means for detecting the position of the type on the type wheel, and a shift reset detection means for detecting the shift position of the type wheel group. It is characterized by having the following.

<Embodiment> FIG. 1 shows the shift selection mechanism and its surroundings in an embodiment of the present invention, in which a carriage 18 is held slidably in the digit direction β with respect to the printer body. A type wheel shaft 12 is arranged on the carriage 18 in the β direction, and is held so as to be rotatable and not to move relative to the carriage 18 in the axial direction. Since the type wheel group 10 is spline connected to the type wheel shaft 12 and biased by the shift return spring 11, its boss portion 35 comes into contact with the shift cam 7 via the shift cam passive body 8. The shift return spring 11 is prevented from coming off by a removable stopper 37 attached to one end of the type wheel shaft 12. The shift cam 7 is held by the carriage side plate 38 so as to be rotatable but not movable in the direction of the type wheel shaft 12, and further supports the type wheel shaft 12 at its center of rotation. The rotation of the shift cam passive body 8 is restricted by a shift guide shaft 36 having one end fixed to the carriage 18. In addition,
The cam slope portion of the shift cam 7 that contacts the passive body 8 is a slope having a stable point corresponding to the number of stages of the type ring group (four stages in FIG. 1).

6-1 to 6-10 in FIG. 1 are the components of the shift clutch 6 in FIG. shift pawl wheel 6
-1, the type wheel shaft 12 is spline-connected and fixed by crimping or a retaining ring. shift cam 7
A shift claw shaft 6-5 is fixed to the opposite side of the cam surface across the carriage side plate 38, and the shift claw 6-2 is rotatable around this shaft. Shift claw 6-
A pin 6-6 is fixed to the tip of the clutch disc 6-4, and engages with an elongated hole 6-7 of the clutch disc 6-4. The amount of rotation of the shift pawl 6-2 is determined by the shape of the elongated hole 6-7 and the amount of rotation of the clutch disk 6-4.
Further, the rotation of the clutch disk 6-4 is subject to impact because another elongated hole 6-8 on the clutch disk 6-4 is engaged with the shift pawl shaft 6-5. Here, the shape of the elongated hole portion 6-8 is set so that the shift pawl 6-2 engages with the shift pawl wheel 6-1 when the clutch disk 6-4 rotates in the γ direction and comes into contact. has been done. In the normal state (the state shown in FIG. 1), the clutch disc 6-4 is biased by the shift pawl spring 6-3, so the notch 6-4 provided on the outer periphery of the disc 6-4 1
1 is locked by a movable piece of the shift trigger electromagnet 5, and the shift pawl 6-2 is connected to the shift pawl wheel 6-1.
is disengaged from the Note that the number of the notches 6-11 corresponds to the number of stages of the type wheel. The tip of the detent spring 6-9 falls into the notch (6-10) when the clutch is not actuated (the state shown in Fig. 1), thereby making the phase of the shift cam accurate and the position of the shift pawl shaft 6-5. This is a spring for stability. Shift reset detector 9
is a switch that detects the reference phase of the shift cam, that is, the shift reference position of the type wheel group.

Coaxially with the type wheel shaft 12, in addition to the above-mentioned mechanisms, a part of a character selection mechanism in the rotating direction of the type wheel and a type position detector are arranged. The selection gear 3-2 and the selection ratchet wheel 4-2 rotate integrally with the type wheel shaft 12, and are driven by the selection drive gear 3-1. On the outer periphery of the selection pawl wheel 4-2, the same number of pawls as the number of positions of the type wheel are formed, and the selection pawl 4-1 is
When the character is rotated in the direction, the selection pawl wheel 4-2 is locked and character selection is performed. Type position detector 17-
1 and 17-2 are means for detecting the amount of rotation of the type wheel shaft 12 to obtain a type position signal and a type position reference signal, and the detection plate 17-1 rotates together with the type wheel shaft 12.

Next, the operation of the above mechanism will be explained. Since the drive source for shift selection is the rotational force of the type wheel shaft 12,
Shift selection must be completed before the character selection process is completed. A specific example will be explained according to the time chart shown in FIG. In this embodiment, the type wheel group is composed of four stages, and each type wheel has 24 characters, that is, 96 characters in total. Also, during one rotation of the shift cam, the standard stroke S ₁ → S ₂ → S ₃ →
Assume that the cam curve has a displacement of S ₄ . When the shift trigger is energized after the type wheel shaft starts rotating, the shift trigger electromagnet 5 in FIG.
The movable piece of the shift clutch disc 6-4 is rotated in the γ direction by a predetermined amount, and the shift claw 6-4 is
2 becomes engaged with the shift pawl wheel 6-1, and the shift cam 7 begins to rotate integrally with the type wheel shaft. The cam curve of the shift cam 7 includes the above-mentioned S ₁ , S ₂ , S ₃ , S ₄
There are four stable points, and the type wheel spindle rotates 1/4 while the cam stroke, that is, the amount of displacement of the type wheel group, changes between adjacent stable points. Therefore, during this period, only 1/4×24=6 pulses of the print position detection signal are detected. When shifting the type wheel group by j steps (j≦3), a position detection signal of 6×j pulses is detected, and the shift trigger electromagnet is energized every time the type position detection signal generates six pulses.

Since character selection cannot be performed while the shift clutch is operating, 6×
Character selection is prohibited during the j pulse. In Figure 3, the type position in the type wheel corresponding to S ₁
It shows the process starting from the state of TP ₀ until selecting the type corresponding to TP ₁₇ in the type wheel corresponding to S ₃ . If the type corresponding to TP ₁₀ of S ₃ is to be selected, the type wheel shaft 12 should rotate one more time to select TP ₃₄ .

Next, FIG. 2 shows an application example of the type serial printer according to the present invention. In the figure, the driving force of a motor 1 disposed on a carriage is inputted to a character selection clutch 13 and a printing clutch 14 via deceleration means A2 and deceleration means B3, respectively. These 2
A selection printing trigger electromagnetic force 4 acts on the two clutch means, and when the trigger electromagnetic force 4 becomes energized, the type wheel shaft 12 stops rotating and character selection is performed.
Next, one cycle of printing process is performed after moving to the current cutoff state. The type wheel shaft 12 continues to rotate until the selective printing trigger is first energized, during which time the shift trigger electromagnet 5 is energized according to the procedure described above, and the shift clutch 6 is energized.
Shifting of the group of type wheels is carried out by the operation of .

In the embodiment shown in FIG. 2, the rotational force of the shift cam 7 is extracted by the driving gear 30 for paper feeding. After the printer prints one line, the step motor 21 reverses and the carriage returns to the standby position.The paper feed drive gear 30 and the paper feed transmission gear 31 engage with each other, and the rotational force of the shift cam is transferred to the gear. A paper feed shaft 34 is driven via the rows 30, 31, 32, 33. Therefore, by rotating the shift cam a predetermined amount while the carriage is in a standby state, it is possible for the printer to feed paper at various line spacings or to rapidly feed paper.

<Effects of the Invention> As described above, according to the present invention, since the printing means and the type ring group are mounted on the carriage, the positional accuracy of the type ring group and the printing means is greatly improved, and the relative positional accuracy thereof is improved. Because it does not change depending on the position of the printed digit, such as the lowest digit and the highest digit, it is less likely to cause missing characters on the left and right sides of the printed characters, greatly improving the printing quality. be.

In addition, since the type selecting means and the printing means are driven alternately by the switching means, when printing, the printing means presses the stopped type wheel to print, so the operation timing of the printing means may be affected. The quality of the printed characters is improved and there are no notches, and since the printing is performed by pressing the type ring, it is possible to provide a low-noise printer.

Furthermore, since the carriage is simply moved in the digit direction to the digit to be printed, the carriage guide shaft that guides the carriage can be used simply for sliding purposes; Since no special processing is required, it is possible to provide a wide printer with excellent print quality, low power consumption, low cost, and a large number of printing digits.

As described above, the practical effects of the present invention are extremely large and remarkable.

[Brief explanation of the drawing]

Figures 1 to 3 all illustrate one embodiment of the present invention, with Figure 1 mainly showing the shift selection mechanism in a perspective view, and Figure 2 showing the printer main body in a block diagram. FIG. 3 is a time chart showing a character selection process including shift selection. FIG. 4 shows an example of a conventional type serial printer. 1... Motor, 2, 3... Deceleration means, 4... Selection/print trigger electromagnet, 5... Shift trigger electromagnet, 6... Shift clutch, 7... Shift cam,
8... Shift cam follower, 9... Shift reset detector, 10... Type wheel group, 11... Shift return spring, 12... Type wheel axle, 40... Type wheel selection cam shaft.

Claims (1)

[Scope of Claims] 1. A carriage held slidably in the direction of the digits, and a plurality of flexible objects rotatably mounted on the carriage and slidably in the direction of the digits, with type arranged around the periphery. a type wheel group formed from a type wheel; a printing means mounted on the carriage for printing by pushing out the type from inside the type wheel; and a drive source for driving the type wheel group and driving the hammer, mounted on the carriage. a DC motor, a type selection means for controlling the rotation of the type wheel group, a switching means for switching the power of the DC motor to either the printing means or the type selection means, and a type selection means for controlling the rotation of the type wheel group. a shift selection means for shifting the carriage; a spacing means for moving the carriage in the digit direction; a detection means for detecting the position of the type on the type wheel; and a shift reset for detecting the shift position of the type wheel group. A type serial printer characterized in that it has a detection means.