JPS5853469A - Printer - Google Patents

Abstract

PURPOSE:To exactly deliver a carriage without causing any bias in printing at low power cost by a method in which the anomalous variation in the position of the carriage is detected by a simple circuit and the carriage is moved to a given position. CONSTITUTION:Usually, when transistors 1 and 4 and transistors 2 and 3 turns On and OFF alternately in sets, electric current is supplied to a motor coil 5 and a carriage moves along a palten to the right, during which clear signal CL is put in a flip-flop 14 and a controller 15 does not work. Under the condition that the transistors 1 and 2 are OFF, no current is supplied to the coil 5, and the carriage is stopped, clear signal CL is not input but the output of the flip-flop remains unchanged. When the carriage is moved by external force, etc., at this time, a counter electromotive force is induced in the motor coil 5, the transistor 13 turns ON, the state of the flip-flop is varied, the controller 15 is actuated, and the carriage is set back to its home position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device, and in particular relates to a printing device in which a carriage on which a print head is mounted is moved between platens (two facing sides and left and right) to perform printing.

In general, there is a possibility that printing misalignment will occur <Efficient at the shortest distance C
: In order to print ( ; ), it is necessary to maintain the stop position of the carriage after printing the previous line. The conventional method was to excite the motor and then immediately move the carriage. However, if closed-loop control is used, the configuration becomes complicated and costs increase, and the motor is constantly moved. The method of energizing the device consumes extra power, and also raises the temperature inside the device due to the generation of heat, which may lead to damage to the device.

Therefore, the present invention eliminates these conventional drawbacks, and is an inexpensive, low-cost method that can reduce power consumption, detect abnormal positional fluctuations when the carriage is stopped (-), and always perform good printing without misalignment. The purpose of the present invention is to provide a printing device with a simple configuration.

According to the present invention C-, in order to achieve this object, a means is provided for detecting whether the carriage has moved from the stop position due to an external force (-) when the carriage is stopped, and when it is detected that the carriage has moved from the stop position, the carriage stops. We adopted a configuration in which the robot is moved to a predetermined position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail in Drawing C.

FIG. 1C-2 shows the structure of the carriage drive and control means used in the printing apparatus of the present invention, and the reference numeral 5 indicates a motor coil.
(-When energized, a motor (e.g. step motor) rotates;
(not shown) is the platen sound; the left and right C
-Moved. One end of this motor coil 5 is connected to the collector of transistor 1.3 (connected), and the other end is connected to the collector of transistor 2.4 (connected to transistor 1.3).
The emitters of transistors 2 and 11' are connected to the power supply E, 11', while the emitters of transistors 3 and 4 are connected to ground (-).

The connection point a of the collector of transistor 2.4 is connected to the voltage dividing point of resistor 10.11 through capacitor 6 and resistor 8, respectively. (- is connected. This voltage dividing point is connected to the base of transistor 13, while the collector of transistor 13 is connected to power supply E2 (-) through resistor 12.
When the flip-flop 14 is connected, the emitter of the transistor 13 is connected to ground (-). The flip-flop 14 has a clear terminal CL, and this signal terminal appears, the flip-flop 14 is reset.The output of the flip-flop 14 is connected to the control section 15, which is connected to the motor drive circuit (-), and the motor is driven by the motor drive circuit C-, and the position of the carriage is adjusted. The terminal SE of the control unit is a terminal to which a signal from a sensor that detects the home position of the carriage is input, and when the home position is detected, the control unit 15 (two persons) is operated via the terminal SE.

In the printing device @1 configured as above, during normal printing, transistors 1 and 4 and transistors 2 and 3 are alternately connected to C.
- It is repeatedly turned on and off, and the motor coil 5 (- is energized from the power source Eli for the upper motor drive, and the carriage moves left and right along the platen (-.) During this time, the clear signal CL is set, and the motor coil 5 (- Second, the output of the flip-flop 14 is reset, and the control section 15 does not operate.

On the other hand, when printing is completed, transistor 1 and transistor 2
is turned off, and the motor coil 5 is cut off from the power source E1, so it is not energized and the transistor 3. The motor stops when only one of C-4 is turned on, and the carriage also stops accordingly. In this state, both ends a of the motor coil 5
, b are equal in potential, and a value obtained by dividing the voltage of the power source E2 by a resistor 10.11 is inputted to the base C2 of the level detection transistor 13 via the capacitor 6.7 and resistors 8 and 9. This value is set lower than the potential v which is required for transistor 13 to turn on, so transistor 1
3 is in the off state, and the collector C of the transistor 13
- indicates a high level signal.

While the motor is stopped, the clear signal CL is reset, but as described above, the collector of the transistor 13 is kept at a high level (-, so the output of the flip-flop 14 does not change and remains in the reset state.

Next (- Like this (- When the carriage is stopped (2) For example, we will explain a case where a large external force is applied and the position of the carriage changes. Now, for example, the motor is stopped with only transistor 4 on. At this time, if the carriage moves from the current stop position due to some reason such as conversion of the ink ribbon, a reverse power is induced in the motor coil 5 (the electric potential at point a rises accordingly. Therefore, the capacitor 6 and resistor 8 The base potential of the cell level detection transistor 13 rises and the transistor 13 is turned on.Then, the collector of the transistor 13 changes from high level to low level C2, and in this case, the clear signal CL
has been reset, the state of the flip-flop 14 changes, its output is set, and the output signal is sent to the control unit 1.
5.

At this time, as shown in step S1 in FIG. 2, it is determined whether or not the flip-flop 14 is set.
2.Printing starts from the current position, but as mentioned above, 1-
When the output signal appears from the flip-flop, as shown in step 531, the second control unit 15 returns the carriage to the home position and then controls the printing of the next line of data from the normal position. In this case, once the motor C is started, the clear signal CL is set, so normal reciprocating printing is performed until the carriage position changes abnormally.
.

The return to the control unit 151 is detected by a sensor (not shown) and its output SE is detected by the control unit 151.

Another embodiment of the present invention is shown in Figure 3, in which the same parts as in Figure 1 are given the same reference numerals in Figure C. In the case of this embodiment (- indicates that the level detection transistor 131- is inputted with the output from one terminal a of the motor coil 5 via the capacitor 6.8, and turns off the transistors 1 and 2 (-). When the transistor 3.4 is controlled to be on, it is possible to detect the state when the motor is stopped (- when an abnormal force is generated and the motor moves from the stopped position) using only the signal from one terminal a of the motor coil 5. In this embodiment, the advantage is that the circuit configuration can be made simpler.

Although the embodiments described above have been explained using a bipolar drive circuit for a step motor, it goes without saying that unipolar or other motors can also be applied.

As explained above (2) According to the present invention, abnormal carriage position fluctuations can be detected with a simple circuit, and accurate carriage feeding without printing misalignment is possible at low power consumption and cost, making it an excellent printing device. is obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the control part of the carriage used in the printing device (2) of the present invention, Fig. 2 is a flowchart explaining the operation, and Fig. 3 is a circuit diagram showing another embodiment of the present invention. Yes. 1.2, 3.4... Motor drive transistor 5...
- Motor coil 13... Level detection transistor 14... Flip-flop 15... Control section

Claims (1)

[Claims] Printing device value that performs printing while moving the carriage carrying the print head opposite the platen;
1. A printing device comprising means for detecting that the carriage is moved from a stop position by an external force when the carriage is stopped, and the carriage is moved to a predetermined position when the detection is performed.