JPS609912B2 - Printer with malfunction detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a static printer with a type wheel, and more particularly to a printer with a device for detecting malfunctions in type selection operations.

The type wheel in a static printer is generally
One type uses a stepping motor to control its rotation or stop, and the other type controls the rotation and stop of the type wheel by selectively transmitting the driving force of a continuously rotating DC motor to the type wheel using a transmission means such as a clutch. There is a type that does.

In the former case, since a stepping motor is used,
The rotation and stopping of the motor can be controlled relatively accurately, but in the latter case, the DC motor is continuously rotating, so if the clutch or other transmission means does not operate effectively, the type wheel will There is a risk that malfunctions may occur, such as not stopping at a desired position or continuing to rotate. The present invention aims to provide a highly reliable printer by equipping a so-called static printer with a malfunction detection device, which is equipped with a transmission means such as a DC motor and a clutch. One example will be explained.

FIG. 1 shows a schematic configuration of the main parts of a printer according to the present invention, and particularly shows a type selection mechanism. A type wheel 1 is provided with a large number of type characters around its periphery, and is rotated by a rotating shaft 2, and the type desired to be printed is moved by a hammer 3.
It is stopped when facing the hammer 3, and printing is performed by the hammer 3. The rotating shaft 2 is connected to a DC motor 5 via a spring clutch plate 4, and the spring clutch device 4 selectively transmits the rotational force of the continuously rotating DC motor 5 to the rotating shaft 2. The spring clutch device 4 consists of two spring clutches 7 and 8 controlled by a control lever 6 driven by an electromagnet (not shown).

The principle of a so-called spring clutch is well known, so its explanation will be omitted, but in the figure, a coil spring 9 is shown.
Note the winding directions of and 10. That is, the coil springs 9 and 1 are wound in opposite directions and operate differentially. That is, it is assumed that the motor 5 and the gear 11 are now rotating in the direction of the arrow in the figure, the switching arm 6a of the control lever 6 is engaged with the notch 12a of the locking plate 12, and the switching arm 6b is engaged with the notch 12a of the locking plate 12. When the gear 11 and the actuating ratchet 13 are not engaged with each other (see FIG. 2), the coil spring 9 between the gear 11 and the actuating ratchet 13 acts to tighten the cylindrical bodies 11a and 13a, while Since the coil spring between the gear 11 and the locking plate 12 prevents the rotation of the locking plate 12, the rotation of the gear 11 is transmitted only to the actuating ratchet 13. , is not transmitted to the locking plate 12. Note that the rotating shaft 2 is a hollow cylindrical body 12 fixed to a locking plate 12, a gear 11, and an operating ratchet 13.
c, 11a, 11a and 13a and is fixed to the actuating ratchet 13.

On the other hand, in the opposite situation to the above, i.e., when the notch foot 6b of the control lever 6 is engaged with the ratchet of the operating chuck 13, and the switching arm 6a is disengaged from the notch 12a of the locking plate 12. In this case, the rotational force of the gear 11 is applied to the locking plate 1.
2 and is not transmitted to the actuating ratchet 13. As described above, in the outside printing machine of the present invention, the rotational force of the continuously rotating DC motor 5 is selectively transmitted to the rotating shaft 2 by the clutch means 4 to select the type desired to be printed. be.

For details of the printer, please refer to the patent application filed in 1984, if necessary.
Please refer to No.-105673 (see Tokuyami No. 56-28886). Reference numeral 14 denotes a detection disk provided to rotate together with the actuating ratchet 13 and provided with a conductive pattern, and detection sliders 15, 16 and 17 are in sliding contact with the disk surface.

This detection disk 14 constitutes a detection device for detecting the position of the type on the type wheel 1, and the number and position of the type and the number and position of the type.
A plurality of radial guiding turtle patterns 14a corresponding to pair 1 [
In this embodiment, 13 patterns] and a common pattern 14b are provided. Reference numeral 19 denotes an actuator for driving the control lever 6, which is not shown, but is actuated in the direction of the arrow in the figure when the electromagnet is excited.

Next, the operation of the above-mentioned printer will be explained with reference to the timing chart of FIG. 3 and FIG. 1.

Now, when trying to print the type "6" on the type wheel 1, first the power is turned on and the motor drive signal is turned on as shown in Figure 3a, and the rotation of the motor 5 is controlled by the idle gear 20, gear 11, and It is transmitted to the rotary shaft 2 via the actuating ratchet 13 and the type wheel 1 and the detection disc 14
begins to rotate, and along with this, a pulse signal indicating the position of the type is continuously obtained from the detection disk (type position detection device) 14, as shown in FIG. 3b. Note that the rising timing of each pulse signal is when the slider 15 and the common slider 16 are electrically connected, and the falling timing is when the slider 17 is electrically connected.
and the common sliding pad 16 are set respectively when electrical conduction occurs. In the case of the present invention, since the type provided on the periphery of the type wheel 1 has one stitch, the sliders 15 and 17 are arranged on a straight line passing through the center of the disk, as shown in FIG. Then, the opening angle Q is 27.69 degrees, and the opening angle 3 is 2
7.69/2 degrees, and one cycle of pulses is generated when the detection disk 14, that is, the type wheel rotates 27.69 degrees. When the type wheel 1 rotates,
The zero position of the type is then detected (FIG. 3c). This zero position is detected when the slider 18 and the common slider 16 are electrically connected.

Once the zero position is detected, the controller (not shown) can identify the pulses from the type position sensing device 14;
At the moment when the pulse corresponding to the character "6" immediately before the character ``6'' to be printed is detected, at the rising edge of the pulse, the control lever 6 is activated in order to switch the spring clutch 4 to stop the character wheel 1. The electromagnet (not shown) of the actuator 19 for driving is excited (FIG. 3d). The actuator 19 and the spring clutch 4 operate with a slight time delay, and as shown in FIG. le 1
The printed character "6" stops facing the hammer 3. at the same time,
The character position detecting device 14 generates a pulse corresponding to the character "6", and when the pulse rises, the electromagnet is de-energized (FIG. 3d), but the actuator 19 still maintains its position. That is, in FIG. 1 or FIG. 2, when the switching arm 6a of the control lever 6 separates from the notch 12a of the locking plate 12, the tip of the arm 6a touches the locking plate 1.
2, and the other switching arm 6b is forced to move the operating ratchet 13 until the tip engages with the next notch 12b again, that is, until the locking plate 12 rotates half a turn. The ratchet is engaged, during which the rotation of the type wheel 1 is stopped and the type "6" is statically printed by the hammer 3 (FIG. 3f). Thereafter, the printing operation is performed in the same manner, and furthermore, the carriage return,
The paper feed operation is performed to complete the printing of one line, but since it is not directly related to the present invention, its explanation will be omitted.
If necessary, please refer to the aforementioned Tokuto No. 54-105673.

As described above, if the printer operates normally, as shown in Figure 3, when the desired type, for example, "6" is accurately selected and the type wheel 1 is stopped, the electromagnet After the power is cut off [FIG. 3d], no pulse is generated from the type position detection device 14, and the control lever 6 is not activated for a certain period of time, as shown in FIG. 3b, that is, in FIG. Until the tip of the switching arm 6a engages with the next notch 12b of the locking plate 12, in other words, the locking plate 12 rotates half a turn, the clutch means 4 switches again, and the operating ratchet 13 resumes rotation. No pulse is generated until
Area A in figure a]. Next, a case where a malfunction occurs will be explained. Malfunctions in this type of printer are
For example, this occurs when the power supply voltage drops and the electromagnet for switching the clutch means 4 does not operate completely. Figure 4 shows that when the character "6" is selected in the same way as in Figure 3, the response of the electromagnet is delayed due to a drop in the power supply voltage, resulting in a malfunction in which the character "7" is selected. The following is a time chart. In addition, in FIG. 4, only the type position detection signal [FIG. 4 a] and the electromagnet drive signal [FIG. 4 b] are shown. As can be seen by comparing FIG. 4 with FIG. 3, the signal E from the type position detection device 14 is recognized in the tin position where the malfunction has occurred, in the main button, and in the area A where the output should be a constant value. Although this example is an example of a malfunction in which the wrong type is selected, another example could be a malfunction in which the type wheel 1 continues to rotate because the electromagnet did not operate at all. In this case, since the clutch means 4 is not switched at all, the type wheel 1 does not stop, and therefore, a phenomenon occurs in which the area A is entirely continuous pulses. The above-mentioned malfunction can be detected by detecting a state in which the character position detection signal turns OFF once and then becomes ON in area A shown in FIG.

FIG. 5 shows yet another example of a malfunction in the character selection operation.

This example shows a malfunction that can occur when there is a misalignment in the positional relationship between the operating ratchet 13, the detection disk 14, and the type wheel 1 in FIG. In this example, when the user selects the character "5", the printed character "5" is selected. In this case, as shown in FIG. 5, the moment the type character "5" is selected, the type wheel immediately stops, so the pulse from the type position detection device 14 is immediately turned ON, as shown in FIG. 5a. It will remain as . On the other hand, as mentioned above, since the electromagnet drive signal is turned off at the rising edge of the type position detection signal, in this case it is not turned off and is continuously maintained in the ON state as shown in Figure 5b. Ru. In order to detect this type of malfunction, as can be seen from Figures 3 and 5, the electromagnet drive signal [Figure 5b] must be detected after a certain period of time after the electromagnet is driven.
All you have to do is check whether it has turned OFF, and if it remains ON, you can judge it as a malfunction.

Also, the printed character “5” in the printed character position detection signal [Figure 5 a]
After the pulse corresponding to " is generated, the pulse corresponding to pulse c corresponding to the printed character "6" in FIG. 6 is a block diagram of a malfunction detection circuit for detecting the malfunction described above, in which an electromagnet drive signal M is inputted to an input terminal 20a, and a type position detection signal W is inputted to an input terminal 20b.

The electromagnet drive signal M and the type position detection signal W are each N.
The signal is input to AND gate 23 through OT gates 21 and 22, and the output of AND gate 23 becomes one input of AND gate 24. The electromagnet drive signal M further becomes a trigger input for the first one-shot multivibrator 25, and the output of the one-shot multivibrator 25 is input to the AND gate 24.
becomes the other input. The output of this AND gate 24 serves as a trigger input to a second wasoshot multivibrator 26. The configuration described above is for detecting the state in which the type position detection signal W changes from ON to OFF after the electromagnet is driven, that is, the point P in FIG. 4a. The first turn shot 25 is triggered when the electromagnet drive signal M [Fig.
This time is normally set to two to three times the period T of the character position detection signal W (FIG. 4a).
Therefore, "After the one shot 25 turns ON!, when both signals M and W turn OFF at point P, the AND gate 23 becomes logic "1" and the AND gate 24 also becomes "
1” logic and the second one-shot 26 is triggered.

The time constant of this second one-shot 26 is also similar to that of the first one-shot 25, from 2 to 2 of the cycle T of the type position detection signal W.
It is set to 3 times the
A "1" output is supplied to one input terminal of the . Then, when the type position detection signal is switched from OFF to ON at point Q in FIG. 4a, the AND gate 27 is activated.
1" logic, and a malfunction detection signal is output from the output end 29 via the OR gate 28. The NOT gate 30 and the AND gate 31 are configured to detect malfunctions shown in FIG. Later, the case where the electromagnet drive signal M (FIG. 5b) is in the ON state is detected.

That is, in FIG. 5, the electromagnet drive signal [FIG. 5b
] turns ON, the output of the first one shot 25 becomes N for a certain period of time, so this output is inverted via the NOT gate 30 and supplied to the AND gate 31. 31 is "0" logic. Then, when the first one-shot 25 is reset after a certain period of time, this output is inverted by the NOT gate 30 and becomes one input of the AND gate 31. is the electromagnet drive signal [Fig. 5b
] is supplied. Therefore, after a certain period of time has elapsed, that is, after the time constant of the first one-shot 25 has elapsed, the AND gate 31' becomes logic "1" and outputs to the output terminal 29 through the OR gate 28. Thus, the malfunction shown in FIG. 5 is detected. According to the present invention as described above,
By utilizing the characteristic of a static printing type printer, that is, the type wheel stops rotating during printing operation, and by detecting the behavior of the type wheel at the point when the type wheel should be stopped, a simple circuit configuration can be achieved. It is now possible to easily detect malfunctions, and virtually control the printer's type selection and printing operations in an open loop.
In particular, printing errors that may occur when the voltage is reduced in printers using dry batteries can be easily detected, and the reliability of the printers can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a type selection mechanism section of a static printing type printer according to the present invention, FIG. 2 is a side view for explaining the positional relationship of main parts of the printer in FIG. 1, and FIG. Figure 4 is a timing chart when the printer of the present invention operates normally, Figure 4 is a timing chart when the printer malfunctions, Figure 5 is a timing chart when the printer malfunctions, and Figure 6 is a timing chart when the printer malfunctions. FIG. 1 is a configuration diagram of a malfunction detection circuit according to the present invention. 1... Type wheel, 2... Rotating shaft, 3... Hammer, 4... Spring clutch, 5... DC motor 6... Control lever, 9, Turtle 0... Coil spring, 11・・・・・・Gear, 12...” Grand stop plate, 13...M
Operating ratchet, 14... Type position detection device [detection disc]. Figure 1: Madara 2: Key 3: Kamamu Kaede key Tominawa Figure 6

Claims (1)

[Claims] 1. A type wheel having a large number of type characters disposed around its periphery and rotatably held; a type position signal generator that generates pulses in one-to-one correspondence with the type characters as the type wheel rotates; A type for stopping the rotation of the type wheel based on a drive signal generated from the time a type position signal generator detects a type immediately before the type to be printed until the type to be printed is detected. wheel stopping means, and detecting means for detecting that the first drive signal has continued for a certain period of time longer than the detection of the print character to be printed after the previous print character is detected; A printer equipped with a malfunction detection device, characterized in that the malfunction detection device detects malfunction of the type wheel stop means.