JPH07290765A - Shuttle control device of dot printer - Google Patents

Abstract

PURPOSE:To accurately adjust the position of a sensor in a short time by logically grasping the error between the reference signal of the sensor and the actual position of the coil of a linear motor in the control of the shuttle of a dot line printer using the linear motor. CONSTITUTION:A weak current is allowed to flow to the coil of a linear motor and the center of the coil is positioned at the boundary of respective magnets and, in this state, the output of the incremental and decremental counter 13 of a shuttle control circuit 9 is latched by a position error memory circuit 15 to set error quantity. The set error quantity is always corrected by the subsequent operation and the position of the coil of the linear motor is accurately detected by the shuttle control circuit. If the error value set to the position error memory circuit 15 is stored in a non-volatile memory 18, this value remains without being erased even when a power source is turned OFF and it can be omitted that position adjusting operation is performed at each time when the power source is turned ON.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shuttle control device for a dot line printer which prints while reciprocating a hammer bank having a plurality of printing hammers mounted thereon using a linear motor.

[0002]

2. Description of the Related Art The construction of a shuttle mechanism portion of a dot line printer will be described with reference to FIG. A hammer bank 1 having a plurality of printing hammers arranged therein, a linear bushing 2 which also serves as a support portion of the hammer bank 1 for reciprocating the hammer bank 1 in the column direction, and a reciprocating movement of the hammer bank 1. A hammer shift mechanism having a guide shaft 4 serving as a guide and at least one hammer bank 1 and a coil 5 connected so as to operate in opposite directions.
A reversing mechanism portion composed of a book timing belt 3 and at least one pair of reversing pulleys 6 supporting the timing belt 3, slits at equal intervals directly connected to the hammer shift mechanism, and a home slit arranged in the center. A linear sensor unit composed of a movable slit 8 and a sensor 7 for detecting the slit of the movable slit 8 by an optical sensor, and a predetermined hammer bank by calculating the position and reciprocating speed of the hammer bank 1 from the output of this sensor 7. A shuttle control circuit 9 composed of a shuttle control circuit 9 for changing a current value to be supplied to the coil 5 according to an error compared with the reciprocating speed curve, a shuttle drive circuit 10 for supplying a current to the coil 5, and different polarities. Cross the lines of magnetic force generated by the magnets 11 arranged so that they face each other at a right angle. Composed of the linear motor unit coil 5 is arranged so.

As shown in FIG. 2, the thrust generated in the linear motor section is generated in the direction of the arrow by Fleming's left-hand rule, and this thrust depends on the positions of the coil 5 and the magnet 11. Change. The thrust is maximized when the central portions of the coil 5 and the magnet 11 coincide with each other, and is minimized when the central portion of the coil 5 coincides with the boundary between the adjacent magnets 11. Further, since the direction and magnitude of the current flowing to the coil 5 are constant, the direction and magnitude of the thrust force change according to the direction of the magnetic force lines.

The reciprocating operation of the hammer bank 1 is represented by a curve as shown in FIG. In the linear motor, the hammer bank, which is an inertial body, decelerates in the reversal section shown in FIG. 3, and further changes the operating direction and accelerates. Therefore, the linear motor requires the maximum thrust in the reversing section. In order to efficiently obtain the maximum thrust in the reversing section, it is necessary to correctly determine the positions of the coil 5 and the magnet 11. The position is determined by the movable slit 8 and the sensor 7 of the linear sensor unit described above.
Judgment is based on the positional relationship with. That is, the central position of the coil 5 is aligned with the boundary between the adjacent magnets 11, and then the position of the sensor 7 is adjusted so that the home slit provided in the movable slit 8 can be detected. By detecting the home slit by this adjustment, the positional relationship between the coil 5 and the magnet 11 can be always grasped, and control can be performed so that the maximum thrust can be obtained in the reversal control requiring a large thrust.

In the prior art, the following method has been used as a method for adjusting the position of the sensor section. First, the positional relationship between the coil 5 and the magnet 11 is adjusted to the above-mentioned state.
Next, the position of the sensor 7 is adjusted so that the home slit is detected.

[0006]

In the prior art, the coil 5 is used.
Therefore, the position adjustment of the magnet 11 and the position adjustment of the sensor 7 are required, and there is a problem that the adjustment takes time and the accuracy is poor.

An object of the present invention is to accurately adjust the positions of the coil, magnet and sensor in a short time.

[0008]

In order to achieve the above object, in the present invention, a paper feeding means for feeding paper in accordance with printing in dot line units and an N dot line are printed at the same time. The shuttle mechanism using a linear motor as a means for reciprocating the hammer bank having a plurality of printing hammers arranged in the direction of the girder and attached to the hammer bank When the hammer bank reciprocates When the hammer bank moves In a dot line printer having a linear sensor that outputs one pulse signal and outputs a home pulse that is a reference signal near the center of one stroke of a hammer bank, the center position of the stroke of shuttle movement that is a reciprocating motion and the center of the linear sensor It is preferable to have a correction circuit that grasps and corrects the positional deviation amount by a logic circuit, and more preferably, Configured with a nonvolatile memory for storing positive value.

[0009]

When a weak current is applied to the coil of the linear motor, the coil stops at a position where thrust in the left and right directions are balanced. This position is a position where the central position of the coil coincides with the boundary between adjacent magnets. In this state, a position error between the movable slit and the home position is logically grasped by a logic circuit.
The actual position of the hammer bank can be grasped as a position corrected by the above-mentioned error with respect to the position detected by the sensor. The above procedure eliminates the need for fine adjustment of the sensor and improves its accuracy. Further, by storing the error amount in the non-volatile memory, it is possible to save the adjustment time by performing the adjustment once in each device.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. The configuration of the dot line printer is the same as that shown in FIG. 1, and the configuration of the shuttle control circuit 9 is different from the conventional one. The shuttle control circuit according to the embodiment of the present invention will be described with reference to FIG. The shuttle control circuit 9 includes the sensor signal processing circuit 1
2, up-down counter 13, shuttle speed detection circuit 14, position error detection circuit 15, shuttle operation control circuit 1
6, microprocessor 17, and non-volatile memory 18
It is composed of.

The position adjusting operation of the coil 5, magnet 11 and sensor 7 of the shuttle control circuit 9 will be described.

(1) Power on First, the power of the printer is turned on.

(2) Initialization 1 Next, the hammer bank 1 is reciprocated once by a command from the shuttle operation control circuit 16 based on a signal from the microprocessor 17. By this operation, the home position of the movable slit 8 is detected and stored in the shuttle control circuit 9. Specifically, as shown in FIG. 4, the sensor processing circuit 12 detects the operation direction of the hammer bank 1 based on the output signals 90 ° out of phase output from the sensor 7. When the home position signal is output during one reciprocating operation of the hammer bank 1, the up / down counter 13 is reset. After that, two kinds of signals are output from the sensor signal processing circuit 12 according to the operation direction of the hammer bank 1, and when the operation direction of the hammer bank 1 is from right to left, the output signal is sent to the up input of the up / down counter 13. Is counted up.
In the opposite case, it is counted down. As a result, the home position is stored.

(3) Initialization 2 A weak current is passed through the coil 5 to stop the coil 5 at a position where thrust in the left and right directions is balanced. This position is a position where the central position of the coil 5 substantially coincides with the boundary between the adjacent magnets 11. As shown in FIG. 5, the thrust is minimized in this state.

(4) Initialization 3 In this state, the shuttle control circuit 9 logically grasps the positional error between the movable slit 8 and the home position. Specifically, the position error storage circuit 15 stores the output of the up / down counter 13 when the linear motor is set to the state (3) for the home position position stored in the process (2). In the example of FIG. 6, the output of the up / down counter 13 in the state (3) indicates “3”. That is, the position error is 3 slits.

With the above processing, the shuttle control circuit 9 controls the home position signal output from the sensor 7 to always correct the slit of "3". This enables shuttle control in which the thrust of the linear motor becomes maximum during the reverse section.

The actual shuttle control controls the position of the hammerbank 1 as well as its operating speed. The shuttle speed detection circuit 14 of FIG. 4 measures the cycle of the output signal of the sensor 7 and sends the speed to the shuttle operation control circuit 16. Further, the activation of each of the initialization processing is instructed by the microprocessor 17.

In the above-described processing, the position error needs to be grasped every time the power of the device is turned on, which causes a problem that the startup time of the device becomes long. In the embodiment shown in FIG. 4, the data stored in the position error storage circuit 15 is stored in the nonvolatile memory 18
The data is stored once in the memory so that the data will not be lost even if the power of the device is turned off. As a result, since the data stored in the nonvolatile memory 18 is transmitted to the position error storage circuit 15 when the power is turned on, it is not necessary to adjust the position error each time the power is turned on.

[0019]

According to the present invention, the position of the sensor can be adjusted accurately and in a short time. Furthermore, by providing a non-volatile memory that stores the correction value of the position error,
There is no need to adjust the position each time the power is turned on.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a shuttle mechanism unit of a dot line printer.

FIG. 2 is an explanatory diagram showing a configuration of a linear motor unit and changes in thrust.

FIG. 3 is a curve diagram of a velocity curve during reciprocating motion of a hammer bank.

FIG. 4 is a block diagram of a shuttle control circuit showing an embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a relationship between a central position of a coil of a linear motor unit and thrust.

FIG. 6 is an explanatory diagram showing a relationship between a sensor output and an up / down counter output of a shuttle control circuit.

[Explanation of symbols]

1 is a hammer bank, 2 is a linear bushing, 3 is a timing belt, 4 is a guide shaft, 5 is a coil, 6 is a pulley, 7 is a sensor, 8 is a movable slit, 9 is a shuttle control circuit, 10 is a shuttle drive circuit, 11 Is a magnet,
12 is a sensor signal processing circuit 13, 13 is an up / down counter, 14 is a shuttle speed detection circuit, 15 is a position error storage circuit, 16 is a shuttle operation control circuit, 17 is a microprocessor, and 18 is a non-volatile memory.

Front page continuation (72) Inventor Masafumi Hiratsuka 1060 Takeda, Katsuta City, Ibaraki Prefecture Hitachi Koki Engineering Co., Ltd.

Claims (2)

[Claims] 1. A reciprocating movement in the digit direction of a paper feed means for feeding paper in units of dot rows and a hammer bank provided with a plurality of print hammers for printing N dot lines at the same time. It is attached to the shuttle mechanism part using a linear motor and a hammer bank as a means for performing the specified amount during reciprocating motion of the hammer bank. When the hammer bank moves, it outputs one pulse signal and outputs a reference signal near the center of one stroke of the hammer bank. In a dot line printer having a linear sensor that outputs a home pulse, a correction circuit that grasps and corrects the deviation amount between the central position of the stroke of shuttle operation, which is a reciprocating motion, and the central position of the linear sensor by a logic circuit A shuttle control device for dot line printers. 2. The dot line printer according to claim 1, further comprising a non-volatile memory for storing the correction value, and omitting a deviation amount detecting operation performed each time the power of the dot pointer is turned on. Shuttle control device.