JPH0342584B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a type wheel stop position adjusting device in a printing device for office equipment.

For printing devices that use type wheels,
When selecting the printing position on the type wheel and printing, if the raised character position on the type wheel is not facing the hammer position correctly due to errors (misalignments) in the mounting positions of each component, printing may not be possible. Characters are missing or unclear on the printed characters,
The quality of the printed characters is uneven, such as irregularities, and the finish is unsightly.For example, if this magnetic printing part is set in a reader and reading work is carried out, it may cause reading errors, which can cause major problems in subsequent paperwork. The result will be left behind. For this reason, it is desirable that the character position of the type wheel is always stopped at a regular position. Conventionally, with this type of printing device, various work has been done to ensure the correct position of the type wheel by fine-tuning the setting of the type wheel or correcting the mounting position of other parts. However, the conventional adjustment method requires a high degree of skill, takes a lot of time for this adjustment, and requires a lot of effort to maintain uniform print quality.

The stop position adjustment device for a type wheel according to the present invention has a sensor plate with a single slit cut out at the end of the shaft that corresponds to the photo sensor unit and serves as a starting point for counting the number of pulses, and a type wheel on the same axis. A rotary switch that rotates a fixed rotary shaft by a stepping motor that is controlled and driven by a motor drive circuit that regulates the motor stop position in advance, and that can increase or decrease the motor stop position in units of one pulse. is incorporated into the circuit, and by increasing the number of pulses required to make one rotation of the rotating shaft as much as possible, the rotation angle of the rotating shaft sent by one pulse and thus of the type wheel is set small in advance. This system combines minute changes in the angle of the rotation axis with fine-grained and subtle corrections to the stop position of the type wheel. In other words, when a deviation occurs from the position of the hammer that strikes the type wheel, the motor and rotary switch can be interlocked in the stepping motor drive circuit, allowing the rotary switch to increase or decrease the stop position of the type wheel in units of one pulse. By incorporating this into a rotary switch, it is possible to quickly, easily and accurately accomplish this type of adjustment work, which requires skill based on intuition, in addition to conventional cumbersome mechanical operations, by simply operating a rotary switch. Next, specific embodiments of the present invention will be described with reference to the drawings.

A sensor plate 5 with a single slit 4 cut therein, which serves as a starting point for counting the number of pulses, is fixed near one end of a rotating shaft 3 supported between a pair of inner and outer frames 1 and 2. A photo sensor unit 7 is arranged so as to embrace the edge of the photo sensor unit 5.

Further, a plurality of main type wheels 8, date type wheels 9, and sub-type wheels 10, 11 are respectively fixed to the rotating shaft 3, each of which can display printing in special magnetic characters readable by a reader. Correspondingly, a hammer 16 is disposed at the tip of a hammer lever 14 that swings around a fulcrum 13 by suction from a solenoid 12, and is retractable from a hammer guide 15. Paper and magnetic special ink ribbon 17 placed between
Printing work is carried out on the paper surface via.

A toothed pulley 19 is fixed to one end of the rotating shaft 3, and is fixed to the inner frame 1, and is controlled and driven based on a motor drive circuit programmed to stop rotation every predetermined number of counted pulses. A toothed pulley 21 is also attached to the motor 20, and at this time, the toothed pulley 19 on the rotating shaft side
The circumference of the stepping motor is twice that of the toothed pulley 21 on the motor side, and the rotation of the stepping motor is connected to the rotating shaft 3 via the toothed belt 22 stretched between both pulleys 19 and 20. It is transmitted at a reduced speed. A rotary switch 24 is installed on the CPU board 25 in conjunction with the motor drive circuit that controls the stepping motor 20 in order to change or correct the recorded motor stop position.

Note that when the slit 4 provided on the sensor plate 5, which is the starting point for counting the number of pulses, corresponds to the detection part (not shown) of the photo sensor unit 7, the first letter of each type wheel corresponds to the hammer 16. Adjusted to stop in position.

Regarding the present invention having the above configuration, a more specific embodiment will be explained with specific numerical values as follows: Type wheel drive stepping motor 2
The circuit is configured so that the motor 20 rotates once with 400 pulses, and the rotation of the motor 20 is controlled by the toothed pulley 1.
The speed is reduced to 1/2 between 9 and 21 and transmitted to the rotating shaft 3. Accordingly, the motor 20 rotates twice for each rotation period of the rotating shaft 3, and thus each type wheel 8 to 11. That is, the rotation angle of the type wheels 8 to 11 rotated by one pulse applied to the motor 20 can be as small as 360°/400×2=0.45°. In the present invention, the entire circumferential surface of each type wheel 8 to 11 is divided into 16 equal parts.
The characters are raised, so the rotation angle required to send one character on the type wheel is 360°/16 = 22.5°, and the number of motor drive pulses required to send one character on the type wheel is 22.5/0.45 = 50. (pulse) is necessarily secured.

The photo sensor unit 7, which is set corresponding to the sensor plate 5 fixed to the rotating shaft 3, detects one slit 4 carved in the sensor plate 5, counts the number of pulses, and stores the pulse number. The motor 20 is controlled to stop when a predetermined number of pulses is reached. By adjusting this predetermined number of pulses, the stopping positions of the type wheels 8 to 11 can be finely adjusted in units of 0.45° (1 pulse). Approximately accurate printing can be expected by applying a predetermined number of pulses stored in advance, but fine adjustment of the type wheel to the desired stopping position by observing the actual printing results is performed using a stepping motor installed on the CPU board. This is carried out by changing the settings of the rotary switch 24, which allows the number of character position selection pulses to be increased or decreased pulse by pulse, in conjunction with the drive circuit of the rotary switch 24.
When this switch is configured with a hexadecimal rotary switch, the central number 8 of the switch is located at the center display position 23 of the rotary switch,
The center value 8 of the switch is set and memorized as a predetermined pulse in advance, and the adjustment range of the wheel is ±8 steps (±0.45° x 8 = ± 3.6°).

If, as a result of printing, the amount of rotation of the type wheel on the hammer is insufficient and a blurred area is visually confirmed in the trailing part of the print, increase the number of pulses, that is, change the setting position of the rotary switch. 9
Alternatively, by changing the settings and modifying the memory in increments of 10..., a slight rotation of the type wheel in 0.45° increments can be ensured.

In accordance with the present invention, extremely detailed and highly accurate stop position correction work for type wheels can be quickly carried out by the very simple means of adjusting a switch, and is not particularly affected by differences in skill. , can ensure homogeneous coordination on site.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of the present printing apparatus, FIG. 2 is a right side view thereof, and FIG. 3 is a view taken along line A--A in FIG. 2. In the figure, 3 is a rotating shaft, 4 is a slit, 5 is a sensor plate, 7 is a photo sensor unit, 8 to 11 are type wheels, 16 is a hammer, 19 is a toothed pulley, 20 is a stepping motor, and 21 is a toothed The pulley, 22 is a toothed belt, and 24 is a rotary switch.

Claims (1)

[Claims] 1. A stepping motor that drives a rotary shaft to which a sensor plate and a type wheel are fixed, each having a slit cut into the shaft that corresponds to the photo sensor unit and serves as a starting point for counting the number of pulses; A motor drive circuit that regulates the position and a rotary switch that can increase or decrease the deviation between the type wheel and the hammer position of the hammer that strikes the type wheel in units of one pulse are provided, and the rotary switch and the motor can be interlocked. A type wheel stop position adjusting device in a printing device for office equipment, characterized by incorporating the type wheel stop position adjusting device.