JPS6056633B2 - Printing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for moving a print head in a printing device such as a serial printer using a pulse motor.

FIG. 4 is a schematic circuit diagram of a printing control device having the same main parts as this type of printing control device already proposed by the applicant (Japanese Patent Application No. 148361/1983 (Japanese Patent Publication No. 26034/1989)). In the figure, 41 is a 4-phase pulse motor, 4
2 is a drive pulley 43 directly connected to the pulse motor 41;
44 is a floating pulley, 44 is a wire stretched between both pulleys 42 and 43, and 45 is connected to this wire 44, and is driven to shift by one character from left to right for each forward rotation of the pulse motor 41. A print head such as a thermal print head 46 inputs a forward rotation pulse MFP or a reverse rotation pulse MBP, and outputs a four-phase excitation signal pH to the pulse motor 41.
This is a drive signal generation circuit that generates a pH of 1 to 4. When one forward rotation pulse MFP is input, this circuit advances the phase relationship of the excitation signal to rotate the pulse motor 41 one step forward, and also generates a reverse rotation pulse MBP. When one input is input, the phase relationship of the excitation signal is delayed in order to reverse the pulse motor 41 by one step, and 47 is the excitation signal PH.
A driving circuit for passing current through each excitation winding of the pulse motor 41 in response to signals pH1 to PH4, for example, a switching circuit connected in series to each excitation winding and controlled by each of the excitation signals pH1 to PH4. Consists of transistors.

48 is a timing detector, and the pulse motor 41
A slit disk 49 that is directly connected to the pulse motor and has slits 49a, 49a, . Photo interrupter 5 consisting of a light receiving element? The rotation detection signal SLP-IN corresponds to one step of rotation of the pulse motor 41.
The correspondence between the slit 49a and the photointerrupter 50 is determined so that the rotation detection signal SLP is completely collapsed before the rotor of the pulse motor 41 reaches the next step.

Reference numeral 51 denotes a stop signal generation circuit, which connects inverters 52 and 5.
3 and monostable multivibrator 54 and differentiator circuit 55
When the rotation detection signal SLP is inputted, it is waveform-shaped by inverters 52 and 53 and then inputted to the drive signal generation circuit 46 as a reverse rotation pulse MBP, which also triggers the monostable multivibrator 54. The trailing edge of the output SS54 is differentiated by a differentiating circuit 55, and is inputted to the drive signal generating circuit 46 via an OR gate 56 as a normal rotation pulse (1).

57 is a monostable multivibrator, 58 is a differential circuit, and the monostable multivibrator 57 is triggered by a start pulse SP that tells the print head 45 to start printing.
The trailing edge of the output SS57 is differentiated by a differentiating circuit 58, and then passes through an OR gate 56 and enters the drive signal generating circuit 46 as a normal rotation pulse MFP.

59 is a busy control circuit which is reset by the start pulse SP and emits a busy signal BUSY, and forward rotation pulse MFP and reverse rotation pulse MBP are output from MFP, MBP, MF.
When input in the order of P, it is reset and the busy signal B
This busy signal BU is used to eliminate USY.
SY is transferred to the computer side, for example, to determine the start and end of a single character printing sequence, and to send the busy signal BUS.
As long as Y appears, the next print information is not transferred.

FIG. 5 is a timing chart of the device shown in FIG.
To briefly explain the operation of this device based on this timing chart, BUSY rises due to input of SP, and SP
SS57 rises at the trailing edge of.

While this SS57 is appearing, printing is performed by the print head 45, the trailing edge of the SS57 is cut out by the differentiating circuit 58, and its output becomes the first MFP and is input to the drive signal generation circuit 46. As a result, the pulse motor 41 rotates forward by one step. Then, SLP-■ appears just before the pulse motor 41 reaches the next step, and in synchronization with this, MBP is input from the inverter 53 to the drive signal generation circuit 46, and the pulse motor 41 is braked in reverse. At the same time, SS54 with a constant time width is emitted from the monostable multivibrator 54, so the trailing edge is cut out from the differentiating circuit 55, and its output is inputted to the drive signal generation circuit 46 as the second MFP, thereby driving the pulse motor. 1 is released, and the print head 45 comes to a stop at a new digit without residual vibration. And above 1
BUSY disappears because the first MFP, MBP, and second MFP are also input to the busy control circuit 59. However, in the case of the above-mentioned printing control device, even though the first MFP is input to the drive signal generation circuit 46, the pulse motor 41 is not activated due to reasons such as the large load on the pulse motor 41. If one step of rotation cannot be performed normally, the SLP signal will not be given to the stop signal generation circuit 51, and MBP1 and the second MFP will not be input to the busy control circuit 59, causing a reset. Not done.

Therefore, the device cannot escape from this printing sequence,
The operation as a printer remains stopped. The present invention has been made to solve the above-mentioned problems, and includes:
Forced MB even if the above SLP case does not occur
An object of the present invention is to provide a printing control device that can generate P and MFP and proceed to the next printing sequence.

The present invention will be described in detail below based on drawings showing embodiments thereof.
FIG. 1 is a schematic circuit diagram of a printing control device according to the present invention, which includes a pulse motor 1, a drive pulley 2, an idler pulley 3, a wire 4, a print head 5, a drive signal generation circuit 6, a drive circuit 7, and timing. Detector 8, slit disk 9, slit 9
a, 9a●● The photointerrupter 10, inverters 12, 13, monostable multivibrators 14, 17, differentiating circuits 15, 18, OR gate 16, and busy control circuit 19 are all 41, 42, 43, as shown in FIG. 44
, 45, 46, 47, 48, 49, 49a, 50, 52
, 53, 54, 57, 55, 58, 56 and 59, respectively. The output of the photointerrupter 10, that is, the rotation detection signal SLP, is sent to the inverter 1 as before.
2 and 13, and the output S of the inverter 13
LP is input to one input terminal of the AND gate 20 and the set terminal of the flip-flop 21.

The start pulse SP is input to the reset terminal 21 of the flip-flop 21, and the control signal SLPF/F issued from the reset output terminals thereof is input to one input terminal of the AND gate 22. As before, the start pulse SP is input to the busy control circuit 19 to set it, and is also input to the monostable multivibrator 17, whose output signal SS17 is input to the differentiating circuit 1.
The output signal BDl8 of the differentiating circuit 18, which rises at the trailing edge of SSl7, is input to the busy control circuit 19 and the drive signal generation circuit 6 as a forward rotation pulse MFP via the OR gate 16 as before. On the other hand, it is also input to the monostable multivibrator 23, and the time limit signal SS23, which is the output signal of the monostable multivibrator 23, is input to the other input terminal of the AND gate 20 and the differentiating circuit 24.

The output signal of the differentiating circuit 24 rises at the trailing edge of SS23, and is inputted to the other input terminal of the AND gate 22 as a backup reversal control signal BD24.
The above SS17 is used as a signal for driving the print operation by the print head 45, like the above-mentioned SS57. Further, the time width of SS23 is determined by applying the MFP provided by upper & pus Dl8, so that the drive signal generation circuit 6 is configured to generate a combination of predetermined excitation signals PHl to PH4, and the pulse motor 1 is adjusted by one step. A forward rotation drive signal to cause the pulse motor 1 to rotate forward is issued, and μSS is maintained until after the timing when the pulse motor 1 rotates forward and the rotation detection signal SLP-■ is generated.
23 is set to last. Therefore, the backup reversal control signal BD24 also appears later than the generation timing of SLP-1N. The output terminals of both AND gates 20 and 22 are connected to the input terminal of an OR gate 25, and the respective outputs MBPl and MBP2 of AND gates 20 and 22 are connected to the input terminal of an OR gate 25.
The OR gate 25 outputs a reverse pulse MBP in response to each input, and the reverse pulse MBP is input to the busy control circuit 19, the drive signal generation circuit 6, and the monostable multivibrator 14.

The drive signal generation circuit 6 outputs an excitation signal for driving the pulse motor 1 in the reverse direction in response to the input of the reverse rotation pulse MBP. On the other hand, the monostable multivibrator 14 is triggered by the MBP and outputs a signal SSl4 with a constant time width, and the differentiating circuit 15 cuts out the trailing edge and outputs a signal BDl5!
, this signal BDl5 passes through the OR gate 16 and is sent to the drive signal generation circuit 6 and the busy control circuit 1 as a normal rotation pulse MFP.
I am trying to input it to 9. The operation of the above-mentioned apparatus of the present invention will first be described based on the timing chart of FIG. 2 in the case where the pulse motor 1 normally rotates one step and the rotation detection signal SLR-■ is obtained.

When the start pulse SP is input, the busy control circuit 19
is set and BUSY rises, and the monostable multivibrator 17 is triggered and SS17 rises at its trailing edge.Furthermore, the flip-flop 21 is reset and the control signal SLPF/F rises from its reset output terminal O.

Printing is performed by the print head 5 by the SSl7, and a BDl8 is cut out at the trailing edge of the β Sl7, and this BDl8 passes through the OR gate 16 and becomes the first MFP, and is connected to the drive signal generation circuit 6 and the busy control circuit 19. is input to. Midfielder
The drive signal generation circuit 6 generates an excitation signal PHL by inputting P.
A forward rotation drive signal consisting of a combination of PH4 to PH4 is generated, whereby the pulse motor 1 is driven in one step of forward rotation. On the other hand, BDl8 is also input to the monostable multivibrator 23 and triggers it, so the time limit signal SS23 rises.
While this time-limited signal is at “H” level, the AND gate 20
will be held. The pulse motor 1 is driven to rotate in the forward direction as described above, and the rotation detection signal SLP-- is obtained from the photointerrupter 10 of the timing detector 8 just before reaching the next step.

Then, the shaped SLP is obtained from the inverter 13, and the SLP is input to the flip-flop 21, which sets it to eliminate the control signal SLPF/F and close the AND gate 22, while being input to the AND gate 20. . At this time, the AND gate is open as described above, so SLP passes through it, and MBP1 responds to SLP.
is output. This MBP1 passes through the OR gate 25 and is converted into MBP by the busy control circuit 19 and the drive signal generation circuit 6.
and is input to the monostable multivibrator 14. M.B.
The drive signal generation circuit 6 generates an excitation signal PHL by inputting P.
- PH4 is generated, and the pulse motor 1 is thereby braked in the reverse direction. In this way S
LP essentially becomes MBP and functions to brake the pulse motor 1 in reverse, and can be called a reverse rotation control signal for the pulse motor 1. In addition, the monostable multivibrator 14 is triggered by the MBP input and SS
l4 is output. Now, the time width of SS23 is determined as mentioned above, so after SLP-1N appears, SS23
falls, and BD24, which functions as a reserve reversal control signal as will be described later, is output from the differentiating circuit 24, but since the AND gate 22 is closed as described above, MBP2 does not appear from the AND gate 22. .

Thereafter, Dl5 is cut out from the differentiating circuit 15 at the trailing edge of SSl4, but this BDl5 is inputted to the busy control circuit 19 and drive signal generation circuit 6 as the second MFP via the OR gate 16, so that the pulse motor 1 The reverse braking is released and stops at a predetermined step position, and the print head 5 stops at a new digit without residual vibration.

In addition, as a result of this second MFP input, the busy control circuit 19 is reset and BUSY disappears, a series of printing sequences is completed, and a state is entered in which it waits for the start of the next printing sequence. By repeating such a sequence, good printing is successively performed. Next, the first MFP
is applied to the drive signal generation circuit 6, but for some reason the pulse motor 1 does not rotate one step normally and the SLP-driver does not appear. Based on the timing chart in FIG. explain.

Start pulse SP is input, and MF' is input by BDl8.
The process up to the point where P is input to the drive signal generation circuit 6 and the excitation of the pulse motor 1 is advanced by one step is the same as the above case.

However, if the pulse motor 1 does not rotate, for example because the load applied to the pulse motor 1 is large, the slit disk 9 will naturally not rotate, so the rotation detection signal SLP and therefore the reversal control signal SLP will not appear. Also, MBPl does not appear. And the rotation detection signal SLP-1N when the pulse motor 1 normally rotates forward due to the input of the MFP.
The time limit signal SS23 falls with a delay from the generation timing (indicated by the two-dot chain line). As a result, the AND gate 20 closes, and the backup reversal control signal BD2 is sent from the differentiating circuit 24.
4 is cut out and enters the AND gate 22. By the way, the flip-flop 21 remains reset by the SP since the SLP is not input, and the AND gate 22 is open at this time. Therefore, BD24 is connected to the AND gate 22.
, enters the OR gate 25 as MBP2, and is further input as MBP to the busy control circuit 19, drive signal generation circuit 6, and monostable multivibrator 14. As a result, a back-up reverse drive signal is generated from the drive signal generation circuit 6, and the excitation of the pulse motor 1 is retreated to the state before the input of the first ■T. On the other hand, the monostable multivibrator 14 is triggered by MBP obtained from this backup reversal control signal BD24,
4 is output, and the trailing edge cuts out BD15, which is inputted to the busy control circuit 19 and the drive signal generation circuit 6 as the second MFP via the OR gate 16. As a result, the busy control circuit is reset and the BUS
While Y disappears, the second MFP input causes the drive signal generation circuit 6 to issue a back-up normal rotation drive signal, giving the pulse motor 1 a chance to rotate one step again. will give. As a result, when the pulse motor 1 rotates in the normal direction, a signal SLP appears, the flip-flop 21 is set by the SLP, and the control signal SLP
-FF disappears, the printing sequence ends, and the state returns to the state where the start of the next printing sequence is to be waited for. Note that even if SLP is input to the AND gate 20 due to the generation of SLP-■, the time limit signal SS23 has already disappeared and the AND gate 20 is closed, so MBPl will not appear due to this SLP, and reverse braking will not occur. Not done.
As detailed above, in the device shown in Fig. 1, if the rotation detection signal SLP is not generated for some reason, the device continues to output the busy signal BUSY and cannot escape from the printing sequence. In the case of the invention, it is possible to generate a back-up MBP and a back-up MFP later than the timing at which SLP-■ is expected to occur during normal operation, so the system does not remain in a busy state. This has the advantage that it can be operated without impairing the printer's functions.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, in which FIG. 1 is a schematic circuit diagram of the device of the present invention, FIGS. 2 and 3 are timing charts for explaining the circuit operation, and FIG. FIG. 5, which is a schematic circuit diagram of a conventional printing control device, is a timing chart for explaining its circuit operation. 1... Pulse motor, 6... Drive signal generation circuit, 8... Timing detector, 14, 1
7,23... Monostable multivibrator, 15,1
8, 24...Differential circuit, 19...Busy control circuit, 21...Flip-flop.

Claims (1)

[Claims] 1. In a control device that drives the print head by a pulse motor, when the pulse motor rotates one step in the forward direction by giving a forward rotation drive signal to the pulse motor to move the print head forward, A time limit signal that appears prior to the generation timing of the rotation detection signal that is issued when rotation is confirmed and disappears after the generation timing, and a backup reversal control signal that lags behind the generation timing of the rotation detection signal, respectively. A circuit that generates a control signal regardless of its presence or absence, a circuit that generates a control signal that appears prior to the generation timing of the rotation detection signal and disappears in synchronization with the generation timing, and a pulse generated by the backup reversal control signal and the control signal. It is characterized by comprising a circuit that generates a backup reverse rotation drive signal to drive the motor in reverse rotation, and a circuit that generates a backup normal rotation drive signal to drive the pulse motor in normal rotation based on the backup reverse rotation drive signal. Printing control device.