JPH022600Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a type position detection device for a printer, and more specifically, a type position detecting device for a printer having a type carrier such as a type belt or a type wheel, in which a large number of types are arranged in a rotational direction. This invention relates to a detection device.

Conventionally, in this type of printer, especially in small printers, a mechanical switch type type position detection device has been frequently used because the structure is relatively simple and inexpensive.

FIG. 1 shows an example of a conventional type position detection device. In the figure, 30 is a code plate that rotates in synchronization with a type carrier, such as a type belt.The contact portion is formed by embossing a single metal plate, and the joint plate is made of insulating synthetic resin. board 31
It is formed as a so-called smoothed substrate in which the contact portion is buried flush with the surface of the substrate 31 by insert or outsert molding. 32...
3 is a contact portion formed on the outer periphery of the substrate 31 for generating a signal corresponding to printed characters; 33 is a common contact formed in an annular shape on the inner periphery of the substrate 31; and 34 is exposed in series with the common contact 33. This is a contact section for generating a code plate reference position signal. 35, 36, 37, 3
Reference numeral 8 designates a fixed contact piece, in which the fixed contact pieces 35 and 36 alternately contact the contact portion 32 as the code plate 30 rotates, and the fixed contact piece 37 contacts the contact portion 34 only once per rotation of the code plate 30. in contact with the fixed contact piece 38
is always in contact with the common contact 33.

Therefore, a code plate reference position signal is generated only once between the fixed contact pieces 37 and 38 for each revolution of the code plate 30, and this signal is made to correspond to a specific symbol or blank in a set of type characters on the type belt. This is used as a type reference position detection signal CHS (hereinafter abbreviated as signal CHS), and by sequentially counting the type corresponding signals obtained between the fixed contact piece 35 or 36 and the fixed contact piece 38 using the signal CHS as a reference, printing can be performed. It is possible to determine the printed text in the position. This is an effective detection method in printers where the type belt rotates intermittently and the drive source must be obtained each time a new type belt starts. The disadvantage is that the number of printed characters in a set to be counted is limited by the number of printed character corresponding signals.

That is, as the number of characters to be printed increases as printers become more sophisticated, the number of contact portions 32 must be increased, but increasing the size of the code plate 30 is limited by space factors. Contact part 3
If 2 were miniaturized and placed close to each other, it would cause malfunctions and there would be manufacturing limitations.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to overcome the above-mentioned conventional drawbacks and to provide a type position detection device with a good space factor that can count a large number of type characters.

In order to achieve the above object, the present invention includes a type carrier having a large number of type characters such as a type belt or a type wheel, a code plate that rotates simultaneously with the type carrier, and a sensor plate that is connected to the code plate by gears. The sensor plate is provided with a contact portion for generating a large number of character corresponding signals in one rotation of the code plate and a contact portion for generating a predetermined number of code plate reference position signals in one rotation of the code plate, is provided with a contact portion for generating a predetermined number of sensor plate reference position signals in one rotation thereof, and generates a type reference position detection signal only when the code plate reference position signal and the sensor plate reference position signal are generated at the same time. The invention is characterized in that it is provided with a gate means for generating the signal.

Hereinafter, details of the present invention will be explained with reference to an embodiment shown in FIGS. 2 to 5.

FIG. 2 is a simplified illustration of a type belt type printer. In the figure, a driving pulley 1 and a driven pulley 2, which are driving means for transporting a type belt 3 on which a large number of type characters are formed at equal intervals, are arranged at a predetermined interval, and an endless type belt 3 is arranged between them. is being passed over. A worm 5 is attached to the rotating shaft of one DC motor 4 serving as a drive source, and the driving force of the motor 4 is transmitted to a main gear 8 via first and second idle gears 6 and 7.
The rotational force from the main gear 8 is applied to the drive pulley 1.
It is now being selectively transmitted to A print/carry gear 9 can mesh with the main gear 8.

One end of a printing/carrying shaft 10 is connected to the printing/carrying gear 9, and this printing/carrying shaft 10 is disposed between the driving pulley 1 and the driven pulley 2, and is connected to the type belt 3. extending in parallel. Printing/
A hammer holder 12 that houses and supports a hammer 11 is attached to the carry shaft 10 so as to be slidable in the axial direction. Furthermore, the hammer holder 12 has a base 1.
The hammer holder 12 is elastically biased toward the home position near the driven pulley 2 by the holder return spring 14.

15 is a paper feed roller, 16 is a flat guide plate that also serves as a platen, and the paper 17 is sequentially sent out from below the paper feed roller 15 and the guide plate 16, and is guided near the outside of the type belt 3. Ru. A selection lever 18 is operated by an electromagnetic solenoid 19 to switch and transmit the rotation of the main gear 8 from the drive pulley 1 to the print/carry gear 9 at a predetermined timing. 20
is a position detecting section provided near the driven pulley 2, which detects a reference position for character selection and a character position. Reference numeral 21 denotes an ink roller that comes into contact with the type portion on the outer periphery of the type belt 3 to apply ink to the type surface.

In FIG. 3, reference numeral 30 denotes a code plate having the same structure as the conventional example, and is attached to the drive pulley 1 so as to rotate therewith. 31, 32,
33, 34, 35, 36, 37, and 38 correspond to the prior art configuration, and 30a is a gear portion of the code plate 30. 40 is a sensor plate whose gear part 40a meshes with the gear part 30a of the code plate 30, and rotates in conjunction with the code plate 30. Similar to the code plate, the sensor plate 40 is also made of a single metal plate that is embossed to form a contact portion, and this metal plate is attached to an insulating synthetic resin substrate 41 so that the surface of the substrate 41 and the contact portion are flush with each other. It is formed as a smoothed substrate buried so as to be flush with each other. 42 is an annular common contact formed on the substrate 41, and 43 is a contact part for generating a sensor plate reference position signal SS (hereinafter abbreviated as signal SS), which is exposed in series with the common contact 42. .
Fixed contact pieces 44 and 45 are in constant contact with the common contact 42, and fixed contact piece 45 is in contact with the contact portion 43 only once per rotation of the sensor plate 40. Signal SS is generated only once per rotation of .

Here, since a rotation transmission error that is unavoidable due to manufacturing occurs in the gear parts 30a and 40a, (or because it is expected) the SS signal generation period _T1 is set as the code plate reference position signal CS (hereinafter referred to as signal CS). ) generation period T ₂ and print corresponding signal generation period
The widths of the contact portions 32, 34, and 43 are set so that T ₁ >T ₂ >T ₃ with respect to T ₃ . In addition, the least common multiple of the number A of signals corresponding to printed characters during one generation of signal CS and the number B of signals corresponding to printed characters during one generation of signal SS is calculated as the number of printed characters in one set on the printing belt 3. is set equal to . And the fifth
As shown in the figure, an AND gate 50 is provided that outputs a High level signal only when the signals CS and SS obtained by the fixed contacts 37 and 45 become High level at the same time, and the High level output signal of this AND gate 50 is is the signal CHS, and the print position is counted based on this signal. Therefore, if the number A is 20 and the number B is 15, their least common multiple is 60, and every time the signal CHS occurs, 60
It becomes possible to detect the position of the printed characters. Note that this least common multiple can be arbitrarily set by changing the diameter ratio of the code plate 30 and the sensor plate 40, and the optimum number can be selected according to the number of characters in one set and the printing format. .

As detailed above, the present invention provides a type position detection device with a good space factor that can count a large number of type characters each time the type reference position detection signal CHS is generated without using a code plate with a large diameter. can be provided, and its practical value is high.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional type position detection device, Figs. 2 to 5 relate to an embodiment of the present invention, Fig. 2 is a simplified explanatory diagram of a printer, and Fig. 3 is a diagram of a type position detection device. FIG. 4 is a partially simplified timing chart, and FIG. 5 is a circuit diagram for generating a character reference position detection signal. 3... Type belt (type carrier), 30... Code plate, 31... Gear part, 32, 34... Contact part,
33...Common contact, 35-38...Fixed contact piece, 4
0...Sensor plate, 40a...Gear part, 42...
Common contact, 43... contact portion, 44, 45... fixed contact piece, 50... and gate.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A type carrier having a large number of type characters, such as a type belt or a type wheel, a code plate that rotates in synchronization with the type carrier, and a sensor plate connected to the code plate by gears. The code board has a contact part and one contact part for generating signals corresponding to a large number of printed characters in one rotation of the code board.
a contact portion for generating a predetermined number of code plate reference position signals by rotation; the sensor plate is provided with a contact portion for generating a predetermined number of sensor plate reference position signals by one rotation; A type position detection device for a printer, characterized in that a gate means is provided for generating a type reference position detection signal only when a plate reference position signal and a sensor plate reference position signal are generated simultaneously. (2) The code plate reference position signal generated by one rotation of the code plate and the sensor plate reference position signal generated by one rotation of the sensor plate are both single, and the printed characters are printed while the code plate reference position signal is generated once. characterized in that the least common multiple of the number of corresponding signals and the number of character corresponding signals during one generation of the sensor plate reference position signal is set equal to the number of characters in a set on the type carrier. A type position detection device for a printer as set forth in claim (1) of the utility model registration claim. (3) The detection range of the sensor plate reference position signal is
2. The type position detection device for a printer according to claim 1, wherein the width of the gear connection between the code plate and the sensor plate is wide enough to allow a rotational transmission error.