JPH0721419B2 - Printer sync signal detector - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a sync signal corresponding to a character arrangement in a small character type printer.

[Prior Art] Conventionally, this type of apparatus is as shown in FIGS. 4 and 5. That is, there is a gap between the flat surface portion 1a of the type wheel shaft 1 and the flat surface portion 2c of the hole of the electrode disc 2, and
On the other hand, the electrode disc 2 is slightly phase-shifted in the rotating direction (arrows A and C), and the circumference 1b of the printing wheel shaft 1 and the circumference 2d of the hole of the electrode disc 2 are different from each other. And are press-fitted with appropriate tightening margins. The sliding contact set 3 is fixed to a frame (not shown). And sliding contacts
For fine adjustment of the synchronization between the signal by 3a and the character arrangement, the character wheel shaft 1 is stopped at a predetermined position and the electrode disk 2 is indicated by the arrow a,
This was done by rotating the necessary amount in the c direction.

Further, as another conventional technique, as shown in Japanese Utility Model Laid-Open No. 56-105807, a support 10 having two pairs of photosensors for detecting the slit of the disk 4 is rotationally moved to adjust the phase. was there.

[Problems to be Solved by the Invention] Problems with the conventional technology are as follows. First,
Since the circumferential portion 2d of the hole of the electrode disk 2 is crushed or deformed by press fitting, it is difficult to finely adjust and the adjustment accuracy is poor. Further, since the type wheel shaft 1 rotates intermittently, when the rotation speed increases, the phase shift between the electrode disc 2 and the type wheel shaft 1 occurs due to the inertia of the electrode disc 2. If the tightening margin between the character type wheel shaft 1 and the electrode disc 2 is tight in order to eliminate this, fine adjustment becomes more difficult and the electrode disc 2 is likely to be cracked. Further, in this type of printer, as mentioned in the description of the embodiment of the present invention, a signal should not be output from the sliding contact 3b while the type wheel shaft 1 is stopped, but the precision of the fine adjustment itself and the electrode pattern are not allowed. If the division accuracy of 2a is poor, the positional relationship between the sliding contact 3b and the electrode pattern 2a may be deviated more than necessary due to the fine adjustment. Therefore, the sliding contact 3b can be stopped while the type wheel shaft 1 is stopped. There was also the drawback that the signal might come out from. In this case as well, when the rotational speed of the type wheel shaft 1 is increased, the vibration of the type wheel shaft 1 at the time of stop is also increased, which is more likely to occur.

Further, in the latter prior art, in order to rotate and adjust the support, the photosensors of the two pairs of detection units fixed to the support are respectively moved with respect to the slits of the disk,
It is not possible to adjust only one photo sensor.
Therefore, when one pulse is generated corresponding to a reference position such as a type and the other pulse is raised at a predetermined position,
If one of them is adjusted to the standard, the other may be out of the standard. In the adjustment process, it is always required to make a balanced adjustment of both of them, and the adjustment work is difficult.

The present invention has been made to solve these problems, and an object of the present invention is to provide a synchronous signal detecting device which can cope with high-speed operation of a printer, has high reliability, and is easy to adjust.

[Means for Solving the Problems] Therefore, in order to solve the above problems, the synchronization signal detecting device for a printer of the present invention is provided with a radial electrode pattern corresponding to the character array of the type wheel that rotates integrally with the type wheel shaft. An electrode disc fixed to the type wheel shaft and a sliding contact member for slidingly contacting the electrode disc to detect contact signals of at least two systems having different phases corresponding to the electrode pattern are provided externally. With the circuit, among the contact signals of at least two systems, the rising action of the first contact signal causes the rising action of the synchronizing signal for printer control corresponding to the type arrangement of the type wheel, and the synchronizing action occurs at the rising of the second contact signal. In a synchronous signal detection device for a printer of a type that performs a signal falling action, an electrode disc having a radial electrode pattern and fixed to a type wheel shaft, and an electrode pattern of the electrode disc. The first sliding contact member that presses the electrode pattern and the position where the first sliding contact member presses the electrode pattern with respect to the center of rotation of the electrode disk are approximately 90
A second sliding contact member that press-contacts the electrode pattern of the electrode disc at a position forming an angle of degrees, and a second sliding contact member that holds the first sliding contact member and the second sliding contact member. And a sliding contact set which is linearly movable so that the position where the members are pressed against each other moves along a substantially normal line of the electrode disk.

[Operation] According to the above configuration of the present invention, when the sliding contact set is linearly moved with respect to the electrode disc, the first sliding contact member moves with respect to the electrode pattern, but the second sliding contact member moves. Since the pressure contact position of the contact member moves along the approximate normal line of the electrode disk,
The phase with the radial electrode pattern does not change.

[Examples] Examples of the present invention will be described in detail below. FIG. 1 and FIG. 2 show an embodiment of the present invention, in which 1 is a type wheel shaft, on which a type wheel (not shown) having characters arranged on the outer periphery is integrally fitted in the rotational direction. Reference numeral 2 is an electrode disc fixed to the type wheel shaft 1 and formed of an electrode pattern 2a corresponding to the type arrangement of the type wheel and an insulating synthetic resin 2b burying the electrode pattern 2a. Reference numeral 3 denotes a sliding contact set including four sliding contacts 3a to 3d and a pedestal 3e for fixing them. The sliding contact 3a and the sliding contact 3b slide on the electrode pattern 2a which is out of phase by about 90 degrees. Also, sliding contact 3b
The pressure contact portion with the electrode pattern 2a is arranged so that the height thereof substantially coincides with the center of the electrode disk 2, and the sliding contact set 3 is a sliding contact in which the sliding contact set 3 moves linearly in the horizontal arrow A and C directions. The pressure contact portion of 3b moves along the normal line of the electrode disk 2. Reference numeral 4 is a frame, and 5 is a mounting screw for fixing the pedestal 3e to the frame 4. The signal waveform obtained by this device is as shown in FIG. 3 when the type wheel shaft 1 is rotating at a constant speed.
A signal e is a printer control synchronization signal formed by an external circuit from the signal a detected by the sliding contact 3a and the signal b detected by the sliding contact 3b. The synchronization signal e is raised at the rising edge of the signal a. , The sync signal e is dropped at the rising edge of the signal b. Further, the signal d detected by the sliding contact 3d is a signal indicating the reference position for associating the synchronizing signal e with the printed characters.

Next, in order to operate this, first, the motor is started, and the type wheel shaft 1 starts to rotate in the arrow A direction via the train wheel system (not shown). Since the electrode disk 2 fixed to the type wheel shaft 1 also starts rotating in the direction of arrow A at the same time, signals a, b and d as shown in FIG. 2 are generated from the sliding contacts a, b and c, respectively. The sliding contact c is a common contact. As described above, the synchronizing signal e is formed from the signals a and b. It is possible to know the timing for stopping a desired character at the print position by sequentially counting the subsequent synchronization signals e starting from the synchronization signal e when the signal d is detected. When the desired type is rotated to the print position, the type wheel shaft 1 is locked by the type wheel shaft locking mechanism (not shown) to print, but the type wheel shaft 1 is stopped. During this time, the synchronization signal e must not be counted. This is because the fact that the synchronizing signal e is counted while the type wheel shaft 1 is stopped means that the correspondence between the letter type and the synchronizing signal e is deviated. By the way, type wheel axle 1
Since there are variations in the position where the printer is locked, variations in the contact portion position of the sliding contact 3a, etc., it is inevitable that a fine adjustment of the synchronization between the signal a and the character arrangement must be performed during printer assembly. In the example and the conventional example, the character wheel shaft 1 is selectively locked at a predetermined character print position, and at this time, the sliding contact 3a
Is finely adjusted in the vicinity of the fall of the signal a (position in FIG. 1). Therefore, when the type wheel shaft 1 is stopped, the signal a repeatedly rises and falls due to the vibration of the type wheel shaft 1. In this state, the synchronization signal e is not counted and the signal b is not output. Will be needed. In other words, when the type wheel shaft 1 is stopped, the sliding contact 3b
There must be a sufficient margin between the electrode pattern 2a and the electrode patterns 2a before and after the electrode. In this case, if the positional relationship between the sliding contact 3b and the electrode pattern is also displaced along with the fine adjustment of the signal a and the character arrangement as in the conventional example, the precision of the fine adjustment itself and the fine adjustment are performed. When the positional accuracy between the pattern and other patterns is poor, the positional relationship between the sliding contact 3b and the electrode pattern 2a is deviated more than necessary, and the signal b is output while the type wheel shaft 1 is stopped. Although there is a possibility, in the present invention, the sliding contact set 3 is finely adjusted by linearly moving in the directions of arrow A and C. For this fine adjustment, the positional relationship between the sliding contact 3b and the electrode pattern 2a is set. Since the sliding contact 3b is arranged at a position where it is not extremely deviated, there is no concern that the signal b will be output while the type wheel shaft 1 is stopped. Further, after the fine adjustment, the pedestal 3e of the sliding contact set 3 is screwed to the frame with the mounting screw 5, so the load resistance force when the sliding contact set 3 is displaced in the arrow A and C directions during the fine adjustment can be controlled. Since the setting can be made with an emphasis on the operability, the operability of the fine adjustment of synchronization is improved and the accuracy thereof is also improved.

[Effects of the Invention] According to the above configuration of the present invention, an electrode disc provided with a radial electrode pattern and fixed to a type wheel shaft, and a first sliding contact member for press-contacting the electrode pattern of the electrode disc. A second sliding contact member that presses the electrode pattern of the electrode disk at a position that makes an angle of approximately 90 degrees with the position where the first sliding contact member presses the electrode pattern against the center of rotation of the electrode disk. , Holding the first sliding contact member and the second sliding contact member, and linearly movable so that the position where the second sliding contact member is in pressure contact moves along a substantially normal line of the electrode disc. Since the sliding contact set is included, the first sliding contact member moves so that the phase changes with respect to the electrode pattern when the sliding contact set moves, but the second sliding contact member Since the position of pressure contact of is constant without changing the phase with the electrode pattern, It suffices to check only the first sliding contact member without worrying about the balance between the two, and it is easy to predict the movement amount for fine adjustment, and the adjustment work is extremely easy, and there is little adjustment variation between printers. The adjustment accuracy is greatly improved.

Further, since the type wheel shaft and the electrode disk are fixed, the phase does not change, so that the speed of the printer can be increased.

As described above, since the function and reliability are improved, the time required for adjustment is shortened, and the cost is reduced, it is possible to provide an inexpensive printer, and the practical effects of the present invention are extremely large. It is a thing.

[Brief description of drawings]

FIG. 1 shows one embodiment of the device of the present invention, (a) is a front view, and (b) and (c) are side views of (a). FIG. 2 shows a sectional view of FIG. 1 (a), and FIG. 3 shows a signal diagram detected by the apparatus shown in FIGS. FIG. 4 shows an embodiment of the prior art, (a) is a front view, (b),
(C) is a side view of (a). Fig. 5 is Fig. 4 (a)
A sectional view is shown. 1 …… Type wheel shaft 2 …… Electrode disk 3 …… Sliding contact set 4 …… Frame 5 …… Mounting screw

Claims (1)

[Claims] 1. An electrode disk provided with a radial electrode pattern corresponding to a character array of a type wheel that rotates integrally with the type wheel shaft, and arranged so as to rotate integrally with the type wheel shaft.
A sliding contact member for slidingly contacting the electrode disk to detect contact signals of at least two systems having different phases corresponding to the electrode patterns, and at least two systems of the contact by an externally provided circuit. Among the signals, the rising edge of the first contact signal causes the rising edge of the synchronizing signal for controlling the printer corresponding to the character arrangement of the letter ring, and the rising edge of the second contact signal causes the falling edge of the synchronizing signal. In the synchronous signal detecting device for a printer of the aspect, an electrode disc having a radial electrode pattern and fixed to the printing wheel shaft, a first sliding contact member for press-contacting the electrode pattern of the electrode disc, The electrode pattern of the electrode disk at a position that makes an angle of approximately 90 degrees with the position where the first sliding contact member presses the electrode pattern against the center of rotation of the electrode disk. A second sliding contact member that is in pressure contact, a first sliding contact member and a second sliding contact member are held, and the position in which the second sliding contact member is in pressure contact is the electrode disk approximate method. A synchronous signal detecting device for a printer, comprising: a sliding contact set that is directly movable so as to move along a line.