JPH0251739B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a printing device that can perform high-speed, highly accurate printing control.

[Prior Art] In printing devices, it has been desired to move a carriage at high speed and with high precision, or rotate a type wheel.

[Objective] An object of the present invention is to eliminate the above-mentioned drawbacks and provide a printing device capable of stopping the motor at high speed and with high precision.

An object of the present invention is to provide a first signal generating means for generating a first speed signal to be targeted based on position error information obtained from current position information and target position information corresponding to the rotation of the motor; pulse generating means for generating pulses in accordance with the pulse generation means;
a second signal generating means for generating a speed signal, the first signal generated from the first signal generating means;
a first deriving means for deriving an analog signal based on a speed signal and the second speed signal generated from the second signal generating means; an analog signal obtained as the motor rotates and a phase of the analog signal; The second step derives a composite analog signal by combining the signals obtained by proceeding with the
A deriving means, and a motor drive means for supplying the analog signal derived by the first deriving means or the composite analog signal derived by the second deriving means to the motor. The object of the present invention is to provide a printing device that does the following.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of the configuration of a type selection control section in a printing device according to an example of the present invention, in which a print instruction signal is generated by pressing a key of a type desired to be printed on a keyboard 1. This print instruction signal is supplied to the central processing unit (CPU) 2, where position instruction data indicating the position from the reference position on the type wheel 3 according to the print instruction is decoded.
This position instruction data is set in latch 4. Therefore, the latch 4 stores the destination position corresponding to the desired type character, ie the stop position of the type wheel 3.

The type wheel 3 is driven by a motor 5.
In addition to the type wheel 3, a photoencoder 6 consisting of a light emitting diode, a photodiode, and a code plate is connected to the drive shaft of the motor 5, and various outputs A, B, and C are connected in accordance with the rotation of the type wheel 3.
Detect. That is, outputs A, B and C from the photoencoder 6 are formed as shown in FIG. Outputs A and B each correspond to one type character on type wheel 3, e.g. 96
When four type characters are placed on the type wheel 3, one rotation of the type wheel 3 generates 96 cycles of the signals A and B. In addition, signals A and B
The phase difference between the two is set to be 90 degrees, so that the direction of rotation of the type wheel 3 can be determined.
One signal C is generated per revolution of the type wheel 3, and this signal C defines the reference position of the type wheel 3. Signals A, B, and C are supplied to comparators 7, 8, and 9, respectively, and compared with the reference level, digital signals D, E, and F expressed as binary values of "1" and "0" are generated.
(See Figure 2). Signals D and E are supplied to the pulse generation circuit 10, and when the pulse G corresponding to each rising and falling edge of the signals D and E and the signal E are behind the signal D, the signal is "0", and is leading in the opposite direction. A pulse that becomes “1” when
In other words, the pulse generating circuit 10 generates a half-direction signal I indicating the actual rotational direction of the motor 5.

The signal F from comparator 9 is the type wheel 3
One is generated per rotation of the addition/subtraction counter 11.
This is a reset pulse that resets the contents of . The addition/subtraction counter 11 is supplied with signals G, I, and F, and counts up or down the pulse G depending on the level of the signal I indicating the rotation direction. Therefore, the output content of the addition/subtraction counter 11 always indicates the rotational position of the type wheel 3, with the rotational position of the motor 5 when the signal C is generated as a reference 0. The addition/subtraction counter 11 is constituted by a normal binary counter, but for convenience, the count value is expressed in quaternary numbers for the lower two bits and in decimal numbers for the upper bits, as shown in FIG. For example, the section of the 15th printed character from the reference position is 150, 151, 1
52,153, and the position at which the printed character should come to rest is the boundary between the count value of the counter 11 and 151,152. The target position data of the type wheel 3 stored in the latch 4 and the current position data of the type wheel 3, which is the volume of the addition/subtraction counter 11, are supplied to the adder/subtractor 12, where both data are compared and the target position data of the type wheel 3 is supplied. Digitally calculate the position error amount up to the value. The sign of this positional error amount indicates the direction in which the motor 5 should rotate. The positional error amount including this sign is supplied to the first conversion table 13 in the form of ROM to obtain a target value signal corresponding to the positional error amount.

The pulse G from the pulse generation circuit 10 is supplied to the pulse interval counter 14, and the generation time interval of this pulse G is measured using the reference pulse from the oscillator 15. Each time the pulse G arrives, the final count contents at that time are calculated. Latch. The latched pulse interval data and rotational direction signal I are supplied to the second conversion table, that is, the reciprocal conversion table 16, and the motor 5
Obtain a value proportional to the speed, including the direction of rotation.
This value is proportional to the average speed of one cycle immediately before the pulse G. In other words, Q appears delayed by one cycle of pulse G (1/4 cycle of signal A).

The target value signal from the first conversion table 13 and the numerical value proportional to the average speed delayed by a predetermined period from the second conversion table 16 are supplied to the adder/subtractor 17 to obtain an error value. The sign of the obtained error value indicates the drive direction of the motor 5, and the absolute value of the error value indicates the magnitude of the drive of the motor 5. This error value is supplied to the D/A converter 18 and converted into an analog error signal O having polarity. This signal O is sent to switch 19 and amplifier 2.
0 to the motor 5 to drive the motor 5.

The adder/subtracter 12 outputs the lower 2 of the counted value of the counter 11.
The upper bits excluding the bit are subtracted from the contents of the latch 4, and a signal K is generated while the position error amount is zero and the contents of the lower two bits of the count value of the counter 11 are counting 1 or 2. This signal K is supplied to the switch 19 as a switching control input, and is also supplied to the delay circuit 23. The delay circuit 23 is
The signal K is delayed for a time sufficient for the type wheel 3 to enter the stop area and stop, and the delayed output activates the hammer control 22.

Further, the signal A is supplied to a phase advance compensation circuit 33 consisting of resistors 27, 28, and 29, a capacitor 30, and amplifiers 31 and 32, and is also supplied to a resistor 34. The output signal L of this phase advance compensation circuit 33 is as shown in FIG. By connecting the resistors 27 and 34 at the connection point 35, the connection point 35
A signal M is obtained by adding the signal L and the signal A. This signal M is applied to the lower connection position of switch 19.

Figure 2 shows the signal waveforms of various parts when driving the motor 5 from the type position ``95'' of the type wheel 3 to the type position ``3'', and the data of the type position ``30'' is latched in the latch 4 as the target position. Then, this data "30" and the count content "950" of the addition/subtraction counter 11 excluding the lower two bits are compared in the subtracter 12, and +40 is obtained as position error data. The calculation procedure in the adder/subtractor 12 is as follows: 30−
Execute 950=-920, and the absolute value of the result is 960/
Since it is 2 or more, the result of -920+960=+40 is output. Through this procedure, the rotation direction and the amount of rotation corresponding to the shortest amount of rotation are determined.

On the other hand, since the motor 5 had stopped, the signals A and B have not changed, and the pulse G has not been generated. Therefore, the count value of the pulse interval counter 14 indicates the maximum count value. When this counter 14 counts the maximum count value, 0 is obtained as the speed value from the reciprocal conversion table 16. Then, this speed value 0 and the instruction value from the conversion table 13 are calculated by the adder/subtractor 17. Now the speed value is 0
Therefore, the indicated value is directly transmitted to the D/A converter 18.
is supplied to At this time, the switch 19 is in the connection position shown, so that the leftmost value O1 of the D/A conversion output O is generated as the signal N, as shown in FIG. The motor 5 is accelerated by this signal and starts rotating, and accordingly, as shown in the second diagram,
Signals A and B change to generate signals G and H, respectively. As a result, the positional error amount decreases, and the count value of the counter 14 also decreases.
The average speed value from reciprocal conversion table 16 will be larger.
Correspondingly, the output of the adder/subtractor 17 decreases, and as shown in FIG. Occur. Due to the closed loop control as described above, the motor 5 rotates at an extremely low speed in the region where the position error is zero, that is, the target position "3". In this way, the position error becomes zero and the value of the lower two bits of the counter 11 becomes 1 or 2.
Then, a signal K is obtained from the adder/subtractor 12, and this output signal K causes the switch 19 to be switched from the position shown in the first figure to the lower position.

When switch 19 is toggled in this manner, signal M is received by amplifier 20. That is, in the stop region, the final 1/2 of the phase advance compensation signal L and the signal A
The drive of the motor 5 is controlled by a signal M that is a combination of four periods. The rotational speed of the motor 5 decreases as the signal M approaches the zero point, and finally stops. Here, if the force applied to the motor 5 is controlled only by the signal A, vibrations will occur, so in the present invention, the signal A is passed through the phase advance compensation circuit 31 and the phase of the signal L and the signal A are shifted by 1/4 period. The motor 5 is driven by the signal M obtained by adding . As a result, the vibration is quickly attenuated, and the motor 5 is stopped at the point where the signal A crosses zero.

As is clear from the above, according to the present invention,
It is suitable for configuration using an LSI-based control device. Furthermore, if this technology is applied to the drive motor of a carriage equipped with a type wheel, LSIization will be further promoted.

[Effects] As detailed above, the present invention makes it possible to provide a printing device that can stop the motor at high speed and with high precision.

As detailed above, according to the present invention, the first position to be targeted is determined based on the position error information obtained from the current position information and target position information corresponding to the rotation of the motor.
a first signal generating means for generating a speed signal; a pulse generating means for generating a pulse as the motor rotates; 2
a second signal generating means for generating a speed signal, the first signal generated from the first signal generating means;
a first deriving means for deriving an analog signal based on a speed signal and the second speed signal generated from the second signal generating means; an analog signal obtained as the motor rotates and a phase of the analog signal; The second step derives a composite analog signal by combining the signals obtained by proceeding with the
A printing device comprising a deriving means, and a motor drive means for supplying the analog signal derived by the first deriving means or the composite analog signal derived by the second deriving means to the motor. It became possible to provide

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the configuration of the printing apparatus of the present invention, and FIG. 2 is a signal waveform diagram of each part thereof. 1...Keyboard, 2...Central processing unit (CPU), 3...Type wheel, 4...Latch,
5...Motor, 6...Photoencoder, 7,8,
9... Comparator, 10... Pulse generation circuit,
11...Addition/subtraction counter, 12...Addition/subtraction device, 1
3... First conversion table, 14... Pulse interval counter, 15... Oscillator, 16... Second conversion table, 17
...Adder/subtractor, 18...D/A converter, 19...
Switch, 20...Amplifier, 23...Delay circuit,
24...Hammer control section, 27, 28, 29, 3
4...Resistor, 30...Capacitor, 31, 32...
...Amplifier, 33... Phase advance compensation circuit, 35... Connection point.

Claims (1)

[Claims] 1. Based on position error information obtained from current position information and target position information corresponding to the rotation of the motor,
a first signal generating means for generating a first speed signal to be targeted; a pulse generating means for generating pulses as the motor rotates; and a current speed based on the plurality of pulses obtained from the pulse generating means. the second representing a part of
a second signal generating means for generating a speed signal, the first signal generated from the first signal generating means;
a first deriving means for deriving an analog signal based on a speed signal and the second speed signal generated from the second signal generating means; an analog signal obtained as the motor rotates and a phase of the analog signal; The second step derives a composite analog signal by combining the signals obtained by proceeding with the
A deriving means, and a motor drive means for supplying the analog signal derived by the first deriving means or the composite analog signal derived by the second deriving means to the motor. printing device. 2. The printing device according to claim 1, wherein the second speed signal is a signal representing an average speed obtained from the plurality of pulses.