JPS60180878A - Overheating protective system for type-selecting motor - Google Patents

Abstract

PURPOSE:To prevent a type-selecting motor from being heated to a temperature not lower than a predetermined temperature, even when high-speed printing is continued for a long period of time, by a method wherein a rise in the temperature of a motor corresponding to the stepping amount for selecting a type of a type wheel is predicted, and the period of time of impressing a selecting signal on the motor is prolonged in accordance with the predicted value. CONSTITUTION:The relationship of the stepping amount (x) of the type wheel from a certain condition to the selection of the next type in a type-type serial printer with the rise in the temperature (y) of the type-selecting motor is empirically determined to be as shown. Based on the results, the temperature rise corresponding to the current condition of the wheel and the stepping amount of the motor for rotating the wheel to bring a desired type to a printing position is calculated, when a type-selecting signal is inputted. According to the calculated value, the period of time of impressing the selecting signal on the motor is prolonged (controlled).

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to an overheat protection system for a type selection motor, and particularly to a protection system for a motor that selects type by rotating a type wheel.

(2) Prior Art and Problems Some types of printers, such as typewriters, telex or computer terminal devices, use a type serial printer as shown in FIG. This printer consists of a carriage motor 2 to which a potentiometer 1 is attached, a rod-shaped screw gear 3 attached to the drive shaft of the carriage motor 2 and having a spiral gear part 9 formed on its outer periphery, and a screw gear 3 that is engaged and supported on the screw gear 3. a carrier unit that can reciprocate in the longitudinal direction of the screw gear 3; a type wheel 10 rotatably mounted on the carrier unit;
A hammer 5 attached to the carrier unit on the side of the type wheel 10, a stay shaft 6 for guiding the reciprocating movement of the carrier unit, a platen 7 around which paper to be printed is wound, and operatively connected to the platen 7. It consists of a paper feed motor 8. The carrier unit includes a carrier 12 that engages with the screw gear 3 and moves along the screw gear 3, and a type selection motor 11 that is connected to the type wheel 10 and rotates the type wheel 10.
A transducer 4 converts the current input to the type selection motor 11. When the printer is in operation, the carrier unit is moved in the column direction, that is, in the longitudinal direction of the screw gear 3, by the operation of the carriage motor 2, while the type wheel 10 is struck onto the platen 7 by the linked operation of the hammer 5 and the type selection motor 11. Then print it on paper. When starting a new line, the paper feed motor 80 is operated to feed the platen 7 13 revolutions for one line. In such printers, the type wheel 10 typically has 96
In order to engrave the next character from the state in which the characters are arranged at equal intervals in the circumferential direction, the character wheel 10 is rotated counterclockwise or clockwise, whichever is closer. To determine the direction, it can be rotated by up to 48 characters (180 degrees).

However, in high-speed printing operations, when the type selection motor 11 rotates the type wheel 10, the flow rate of the type selection motor 1 increases over time, and due to the heat, the type selection motor Occasionally, the transduu IJ'4 attached to the rear side of the printer 11 would malfunction, causing the printer to stop.

(3) Purpose of the Invention The present invention was made by focusing on the above-mentioned conventional problems.The purpose of the present invention is to prevent the temperature of the type selection motor from rising above a certain value even when high-speed printing is continued for a long time. It is an object of the present invention to provide an overheat protection system for a type selection motor that prevents failures such as stoppage from occurring, thereby solving the above-mentioned conventional problems.

(4) Structure of the Invention In order to achieve the above object, the present invention provides a printer equipped with a type wheel.
The main idea is to predict the temperature rise of the motor according to the step amount of the type wheel until the next type is selected, and to reduce the load on the type selection motor based on this predicted value. . The temperature rise of the motor can be predicted by using the motor vAr! instead of directly detecting the motor temperature. i
This is done by focusing on the relationship between this and the step amount of the type wheel.

In other words, the operating mode of the type selection motor differs depending on the step amount of the type wheel, and the amount of heat generated also changes, so whether the temperature of the type selection motor is trending upward or downward by capturing this difference in heat generation. determine whether it is in
This is to adjust the load on the type selection motor.

(5) Embodiments of the invention First, in a type serial printer as shown in FIG. 1, the relationship between the step amount of the type wheel 10 and the temperature rise of the type selection motor 11 corresponding to that step is It will look like Figure 1.

This graph diagram shows that when the type selection motor 11 is made to select the type in step fil (referred to as i) a sufficiently large number of times (referred to as N), the tm degree of the type selection motor 11 increases and reaches a steady state. This figure shows the results of detecting the step amount and the above-mentioned steady temperature for i-1, 2, . . . 48 degrees. As is clear from this graph, the number of steps of the type selection motor 11 is %1 when the step amount is 1 to 12. ．． Haki 1+ L @lII M
Knee, -p Otori 4 Q tMlr' 31-1- ”
kp In L - decreases. This is because when the step amount is 1 or 2, the amount of operation of the type selection motor 11 itself is small, so the crosstalk is low, and as the step amount increases, the application of acceleration current and deceleration current increases, and the temperature also rises. However, when the step amount exceeds 12, the type selection motor 11 first accelerates, then rotates at a constant speed, and then decelerates in order to perform this operation in the shortest time during the selection operation to determine the type that can be requested. This is because the application of current is stopped for a predetermined period of time after entering the operation.

Therefore, based on this temperature-step amount characteristic, it should be possible to predict the temperature rise of the type selection motor 11 by looking at the operating status of the type selection motor 11 during printer operation.

FIG. 3 shows a flowchart of an example in which overheat protection of the type selection motor 11 is implemented in accordance with the above idea.

Basically, a temperature counter and a timer are built into the circuit that controls the type selection motor 11, and when a step in a high temperature area is selected, the temperature counter is counted up. , shows an operating procedure in which the temperature counter is decremented when a step included in the low m degree region is selected, and the load on the type selection motor 11 is reduced when the temperature counter value reaches a certain value. It is. To count up or decrement the 1B mark counter, for example, in Fig. 2, set the line P corresponding to the temperature as the reference line, and when a step included in the area above this reference line P is selected. The temperature counter is incremented by +1, and when a step included in an area below the reference line P is selected, it is incremented by -1. In addition, different from this, a line Q corresponding to the temperature is set as the upper reference line and a line R corresponding to another temperature lower than this temperature is set as the lower reference line.
When a step included in the area above is selected, the temperature rise is significant, so add +2 to the temperature counter,
Weight is added to the rise and fall of the temperature counter by adding +1 between the reference lines Q and R, and adding -1 below the lower reference line, and calculates the temperature value close to the graph in Figure 2 by adding weight to the temperature counter. It is possible to express it by the following expression. In addition, the type selection motor 11 may temporarily stop due to idle or pause, etc., and the temperature drops due to heat radiation during this pause, so this state is also taken into account in the data of the temperature counter, so the above-mentioned A timer is used.

70chi1 in Figure 3! - When the step amount is 3, a reference line (corresponding to the lower reference line R in Fig. 2) is drawn, and for steps included in the area above this reference line R, the temperature counter is is set to add +1, the step included in the area below is set to perform 11 additions, and the pause time required for idle etc. is 0.5 seconds, that is, 0.
The procedure for operating the printer and measuring the temperature under the condition that when no data signal is applied for 5 seconds, the temperature counter is incremented by 1 is shown. - Note that a temperature increase register SR is used as a temperature counter, and when this temperature increase register SR is 0, even if a step in an area below the reference line R is selected, 11 addition is not performed.

First, in a first step 20, the temperature rising register SR is cleared to zero. In the next step 21, the type selection motor 11
Whether or not the rotation of 3 steps or less is selected is detected every time the type selection motor 11 operates, and if the selected step amount exceeds 3, the temperature increase register SR is set to +1 at stage 111!24. After the addition, the process proceeds to step 25, and when the value is 3 or less, it is detected in step 22 whether the value of the temperature increase register SR is 0 or not. As a result of this detection, when the value of the temperature increase register SR is 0, the process directly proceeds to step 111i25, and when it is not 0, the process moves to step 25 after the stomach thirst register S11 is increased by 11 in step 23.

In step 25, it is detected whether there is a state in which there is no data input for 0.5 seconds due to idle or the like.

If such a condition does not exist, the process directly proceeds to step 27, while if the above condition exists and the temperature increase register is not zero, one of the temperature increase registers SR is changed to step 26.
After carrying out the addition, a transition is made to step 27. In this way, the temperature increase register SR repeats addition and subtraction in nine operations up to step 26, and the displayed value changes. Then, based on this display value, the printer operation at the time of line feed is υ controlled. That is, in step 27, a timer is set to determine the line feed operation time. There is a method of setting the timer, for example, in correspondence with the upper three bits of the temperature rising register SR. That is,
For example, set the value of the upper 3 bits (from 0 to 7) to 0.25.
The value multiplied by (sec) is set as the timer setting value, and step 2
This is done by giving a pause for the time equal to the timer setting value mentioned above when performing the line feed operation in step 8. The reason why the temperature and height of the type selection motor 11 is adjusted by changing the operation time at the time of line feed is because there is no need to type on the platen 7 during this line feed operation and the type selection motor 11 is at rest. This is because if the operating time is changed, the rest time of the type selection motor 11 can also be changed. Therefore, this method is only one example for implementing the present invention, and other methods, for example, the printing speed can be adjusted in accordance with the count value of the temperature increase register SR.

6) As described in detail, according to the present invention, depending on the step amount of the type wheel from the state in which the type wheel is formed to the selection of the next type, by using a heating register or the like, Since the temperature rise of the type selection motor is predicted and the load on the type selection motor is reduced based on this predicted value, problems such as the transducer erroneously moving and the printer stopping due to the type selection motor overheating do not occur. No. Furthermore, prediction of the temperature rise by adjusting the temperature increase register or setting the timer can be easily realized by operating a software program, so that various effects can be obtained, such as eliminating the need to complicate the structure of the printer itself.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing the structure of a printer to which the present invention is applied, and FIG. 2 is a graph showing the relationship between the step amount of the type wheel and the temperature rise of the type selection motor 11, which is the basis of the present invention. Flowchart 1 in FIG. - FIG. 2... Carriage motor 3... Screw gear 4... Transducer 5...
Hammer 7...Platen 10...Type wheel 11...Type selection motor S
R...Temperature rising register (temperature counter) special v1 applicant Fujitsu Ltd. No. 1rA Figure 2 Figure 3 0

Claims (1)

[Claims] In a type printer in which a type selection motor is operated in response to a type selection signal, a type wheel is rotated to select a type based on the selection signal, and the type is struck toward a platen. a temperature detection means for outputting a temperature increase value corresponding to the next type selection motor;
An overheat protection method for a type selection motor, characterized in that application of a selection signal to the type selection motor is extended based on this output value.