JPS5933118B2 - printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to printing control of a printer device, and particularly to printing magnet energization control of a printer device that performs printing by colliding type or needles onto printing paper with the force of a magnet.

In a print printer in which a print wheel is struck with a hammer by magnetic drive, or in a dot printer in which a plurality of needles are applied to print paper by magnetic drive, the print density differs depending on the thickness of the print paper. Therefore, it has been proposed in the past to adjust the energizing current value of the printing magnet according to the type of type or paper thickness to be printed (for example, in Patent Publication No. 51-107).
38, JP-A-51-25931). However, when adjusting the energizing current value of the printing magnet in accordance with the paper thickness, this adjustment is performed by selectively energizing a switch, and therefore must be adjusted manually. A first object of the present invention is to automatically perform printing pressure control corresponding to paper thickness.

In order to do this, it is necessary to automatically detect the printing paper thickness, but conventional automatic paper thickness detection is performed by converting the movement of a contactor that makes sliding contact with a piece of paper into an impedance change and detecting this. However, when detecting the paper thickness of printed paper made of multiple sheets of thin carbon paper, the paper thickness detection is inaccurate, and in particular, erroneous detection may occur due to vibrations of the printer device.

Therefore, a second object of the present invention is to provide a print magnet drive control device that can reliably detect paper thickness and can reliably control print magnets corresponding to the paper thickness. Furthermore, when the paper thickness differs, the optimum value of the forced movement stroke of the type or needle differs, and the print density changes depending on the forced movement stroke.

Therefore, a third object of the present invention is to provide a printing magnet and a drive control device that can automatically adjust the energizing current value and energizing time of the printing magnet in accordance with the paper thickness.

In order to achieve the above object, in the present invention, the paper thickness indication on printed paper is detected by a detection means corresponding to the display material.

In general, the types of printing paper used in printers are limited, and are processed and printed in advance for use in printers.

Therefore, holes and ink printing can be made on the printing paper during its processing or printing process to indicate the paper thickness of the printing paper. Therefore, in the present invention, a means for detecting these holes and ink printing is installed in the printer device, and these indications are thereby detected. In this way, all of the display detection and detection signal processing can be performed digitally, and there is no detection error, the detection is reliable, and the signal processing is simple. FIG. 1 shows an example of carbon paper in terms of paper thickness.

In FIG. 1, 1 is a slip made of multiple sheets of carbon paper, and 2 is a paper thickness mark. This paper thickness mark 2 was printed at the same time as the notation on the slip 1, and the two marks 2,
If the paper thickness is displayed using a combination of 3, and the presence of marks is represented by "1" and the absence of marks is represented by "O", the presence or absence of marks 2 and 3 will be displayed as shown in Table 1 below. The paper thickness is displayed by combining them.By increasing the number of marks that are combined, the number of paper thickness displays can be further increased, and the paper quality can also be indicated as necessary.

FIG. 2 shows how marks are detected on the slip 1.

In FIG. 2, 6 is a sprocket wheel, 7 is a paper feed motor, and 4 and 5 are photoelectric detectors. Photoelectric detector 4, 5
It is installed in a paper cutter. A perspective view of FIG. 2 is shown in FIG. 3. In FIG. 3, 8 is a paper cutter. A sectional view taken along the - line of the paper cutter 8 is shown in FIG.

In FIG. 4, 9 is a light emitting element, 10 is a transparent plastic ball, 11 is a transparent plate, and 12 is a photoelectric conversion element.
The light emitted from the light emitting element 9 is focused by the ball 10 and then the transparent plate 1
1 and hits the slip 1, and its reflection passes through the photoelectric conversion element 12.
The light is received by This photoelectric detector 5 is arranged at the mark 3 detection position, and a photoelectric detector 4 having a similar structure is arranged at the mark 2 detection position. These photoelectric detectors 4
, 5 detects a decrease in the light reception level due to the arrival of mark 2. Note that the mark 2 may be replaced with a hole. When doing so, it is sufficient to open the sprocket holes at the same time as punching the sprocket holes in slip 1. If a hole is used instead of mark 2, the light emitting element and the photoelectric conversion element should be placed opposite each other by placing a slip between them, or the contact should be in sliding contact with the printed paper so that it falls into the hole. At this time, the microswitch may be closed, or furthermore, the electrode plates may be opposed to each other to detect changes in capacitance due to the holes. An example of a circuit for processing signals of the photoelectric detectors 4 and 5 is shown in FIG.

In the signal processing circuit 13 shown in FIG. 5, resistors R2 and R3 and a zener diode ZDl connected to the photoelectric conversion element 12 prevent the output level of the photoelectric conversion element 12 from changing in response to a voltage change in the input voltage Vcc. Configure a constant voltage circuit to prevent this. VRl is a variable resistor for adjusting the reference level for mark detection. When the photoelectric conversion element 12 is currently receiving light (when mark 2 has not arrived), the output terminal of the photoelectric conversion element 12 is positive with respect to the ground potential. This output is inverted and amplified by the operational amplifier 0PA1, and the input terminal (to) of the operational amplifier 0PA2 is at a negative potential with respect to the ground potential.
It is inverted and amplified at the output terminal, which is a positive output with respect to the ground potential. The potential at the input terminal of the inverter INVl is maintained at a constant voltage (for example, 5V) by the Zener diode ZD2.
) and becomes the input signal of the JK flip-flop FF1, and is reset to O by the input pulse at the CP terminal. Therefore, its Q output is at a low level. Now, the sixth
Assume that the pulse CPl shown in the figure and the clock pulse CP2 are applied to the AND gate ANDl, and when mark 2 arrives at the position of the photoelectric detector 4 at time t1, the output potential of the photoelectric conversion element 12 decreases, and the inverter INVl
The output A of becomes high level. flip-flop 'F'F
Since the output of 1 rises at the falling edge of pulse CP1, it becomes B shown in FIG. 6, and similarly, the outputs of flip-flops FF2 and FF3 become C and D shown in FIG. 6, delayed by one pulse. The output E of the AND gate ANDl is B,
The logical product of 'C and CP2 results in the form of E, that is, the inverted waveform shown in FIG.

Flip-flop FF3 is cleared by the inversion r of E, and C
At the fall of , a new mark detection signal D is set in the flip-flop 'FF3. The output Q of this FF3 maintains a high level "1". PC is a clear signal pulse applied when power is turned on. When neither marks 2 nor 3 are detected, flip-flop FF3 is held in the previous state,
When at least one of marks 2 and 3 is detected, the previous state is set by E and a new mark detection signal is set in flip-flop FF3.

Before mark detection or when the power is turned on, the output terminal Q of flip-flop FF3 is set to O by the auto clear pulse PC.
It is set to 1 when a mark is detected. 7th
The figure shows an example of the configuration of the first magnet energization control circuit 14 and the second magnet energization control circuit 15.

In FIG. 7, 16 is a printing magnet energizing circuit;
The magnet coils L1 to L7 are energized by the energizing terminals N1 to N.
By applying a signal to 7, transistors Tr2~
The conduction of Tr8 is controlled, and the current flow of the coils L1 to N7 is controlled. The current value and energization time of coils L1 to L7 are as follows:
It is determined by the bias voltage applied to the bases of the transistors Tr2 to Tr8 and the bias voltage application time, respectively. A voltage determined by the logical product of a constant voltage applied from each of the energizing terminals N1 to N7 and a voltage applied from the circuit 15 is applied to the bases of the transistors Tr2 to Tr8. In the first magnet energization control circuit 14, V
R2 and C2 are variable resistors and capacitors for determining the reference energization current width, RlO and Rll are resistors for making the energization width variable, and MMB is a mono-multivibrator.

A synchronizing pulse TR that determines the dot cycle of the printing needle is input to the mono-multivibrator MMB.
Note that the biasing terminals N1 to N of the printing magnet biasing circuit 16
A constant voltage energizing signal is selectively applied to 7 in synchronization with this trigger pulse TR. Now, assuming that marks 2 and 3 are attached to the printed paper as shown in Table 1, the outputs D and F of the output terminals 0ut1 and 0ut2 of the signal processing circuit 13 will be as shown in the following Table 2. .

As shown in FIG. 8, the resistors RlO, Rll and Rl3 are widest when the output pulse width of the mole multivibrator MMB is W1 when one or both of inputs A and B are present, and W2, W3 It is set to become narrower as the distance increases.

B1 and B2 are open collector type buffer amplifiers. This constant voltage output pulse with a variable pulse width is applied to the transistor Tr of the print magnet energization circuit 16 via the buffer amplifier B3 of the second print magnet energization control circuit 15, the operational amplifier 0PA3, and the transistor Trl.
It is applied to Tr8. As a result, the transistor T
The conduction width of r2 to Tr8 is the pulse width shown in FIG.
In the second printing magnet energization control circuit 15, when there is an input to the relationship shown in Table 2 (when W3), the conduction rate of the transistor Trl is highest (lowest impedance), and when W1, the conduction rate is highest. is low, and the resistors Rl5, Rl6, VR
3 and Rl8 are determined, and the variable resistor VR3 is
This is for adjusting and setting the conductivity of the transistor Trl to be high or low as a whole.

Now, let the voltage at the upper end of variable resistor VR3 be V, and variable resistor V
The voltage of the slider of R3 is E2, the voltage of resistor R2l is el,
Let the output voltage of operational amplifier 0PA3 be 几子→EO, and EO
+1(E2-e1) holds r)o8, then
The inverting input e1 is fixedly determined by R25 and R2l.

Therefore, if the output of the first printing magnet energization control circuit 14 is 1 (pulse in FIG. 8), and A=1, B=
1, E2 is determined by Rl7, Rl8 and VR3.

If E2 at this time is Vl, then the following equation is obtained.

The voltage V,, at the upper end of VR3 at this time is, however, VR3
b is the resistance value below the slider of VR3. Also, A=1
, B=0, the output terminal of the buffer amplifier B5 is grounded, and the resistor Rl6 is connected to VR3 and Rl8.
are connected in parallel.

When A=0 and B=1, Rl5 is connected in parallel to VR3 and Rl8. This A=1, B=0 and A=
0, B=1, the voltage at the top of VR3 changes, and E
2 changes, and EO changes accordingly. Therefore, by setting the resistors Rl5 and Rl6 and the resistors VR3 and Rl8, as shown in FIG.
The output voltage EO changes. The pulse width of this EO is the output pulse width of the first printing magnet energization control circuit 14.
As a result, the base bias voltage of transistor Trl takes the form shown in FIG. In this way, the emitter voltage of the transistor Tr becomes a pulse waveform similar to the pulse waveform shown in FIG.
6 transistors Tr2 to Tr8. In addition,
The power supply that applies voltage VMG to the coils L1 to L7 is a rectified commercial alternating current and is not stabilized. If this is used as a stabilized power supply, a constant current must be given to each coil for various energization modes from 1 to 7 coils L1 to L7. A separate power source is required, which is large and expensive. Therefore, in this embodiment, the voltage VMG is a rectified commercial AC, but due to fluctuations in the power supply voltage and simultaneous energization coils L1 to
Coil L due to variation in voltage VMG due to difference in number of L7
Operational amplifier 0 is used to prevent fluctuations in the energizing current of 1 to L7.
A reference voltage is applied to PA3 from voltage VMG through resistor R25. By doing this, the voltage V
When MG increases, the reference voltage of operational amplifier 0PA3 increases, and the bias of transistor Trl becomes deeper.
Further, when the voltage VMG decreases, the reference voltage of the operational amplifier 0PA3 decreases, and the bias of the transistor Trl becomes shallower. In this way, a constant current always flows through the coils L1 to L7 despite fluctuations in voltage VMG. In the print magnet energizing circuit 16, when there is no input to the terminals N1 to N7, the output terminals of the buffer amplifiers B6 to B12 are at ground level.

Therefore, even if an energizing pulse arrives from the circuit 15, the transistors Tr2 to Tr7 are not energized enough to energize the coils L1 to L7. When a print signal arrives at the terminal N1, for example, the output terminal of the buffer amplifier B6 is separated from the ground potential. Therefore, the circuit 15 is connected to the base of the transistor Tr2.
A pulse voltage is applied to the coil L1, and conduction occurs in proportion to the pulse voltage during the width of the pulse, thereby energizing the coil L1. By controlling the biasing energy and time of the printing magnet as described above, the printing needle moves as shown in FIG. 11.

That is, corresponding to Wl, W2, and W3 shown in Table 2, the distance between the tip of the needle in the standby position and the surface of the printing paper, that is, the clearance, is different from Al, A2, and A3. On the other hand, the forced movement locus of the needle tip takes the shape shown by the solid line due to the above-described energization of the magnet. The dotted line is the free flight trajectory. When there is only one sheet of printing paper, the clearance A1 is large at W1, so it is necessary to increase the amount of movement of the needle, and the printing pressure may be small. In the present invention, as described above, the excitation current is made long and small at W1, so this condition is fully satisfied. When the number of printed sheets is large (3 sheets) W3, the needle movement amount may be small, but the printing pressure must be increased, and the present invention satisfies this requirement. In this way, print quality of constant density is obtained. Furthermore, since wasteful energy is not used in the print head, the heat generated by the print head is reduced, and the bun size is also reduced. In Tables 1 and 2, if there is no mark, it is treated as standard printing paper, that is, general-purpose printing paper, so that a constant density of print quality can be obtained on general-purpose printing paper in the same way as above. It will be done. In this case, when the Q output of flip-flop F3 is O, the paper may be treated as general-purpose printing paper. In the above description, an example was given in which printing is performed using a needle, but the present invention can be similarly implemented in the case where printing is performed using printed characters.

Further, the printing paper is not limited to one made by laminating carbon paper, but may be a magnetic card or other sheet-like paper. As described above, according to the present invention, the paper thickness can be detected through digital processing by detecting the paper thickness indication on the printing paper, and the printing pressure of the printing magnet can be automatically controlled in accordance with the paper thickness, making it possible to stably It is possible to obtain print quality with a constant density.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing printed paper with a paper thickness indication, FIG. 2 is a side view showing a detection mode of the paper thickness indication, and FIG. 3 is a perspective view. FIG. 4 is a sectional view taken along the line -- in FIG. 3. FIG. 5 is a circuit diagram showing one example of the configuration of a signal processing circuit used in the present invention, and FIG. 6 is a time chart showing its input/output signals. FIG. 7 is a circuit diagram showing an example configuration of the first and second printing magnet energizing control circuits used in the present invention,
FIG. 8 shows the output pulses of the first printing magnet energization control circuit 14. Figures 9 and 10 are the second
3 is a graph and a waveform diagram showing the level and pulse width of voltage EO of the printing magnet energization control circuit 15 of FIG. 1st
FIG. 1 is a graph showing the trajectory of the needle movement when the printing needle is energized according to the present invention. Note that the same reference numerals in the figures indicate the same or equivalent parts. 1... Slip, 2, 3... Paper thickness mark, 4, 5...
Photoelectric detector, 6...Sprocket wheel, 7
...Pulse motor, 8...Paper cutter, 9...Light emitting element, 10...Plastic ball, 11...Transparent plate, 12. ...
...Photoelectric conversion element, 13...Signal processing circuit, 1
4...First printing magnet energization control circuit, 1
5...Second printing magnet energization control circuit, 1
6... Printing magnet biasing circuit.

Claims (1)

[Claims] 1 A detector that detects the paper thickness indication attached to the printed paper and a signal processing circuit that receives the detection output of this detector and outputs a paper thickness signal are installed, and the paper thickness of the printed paper is automatically detected and the paper A printing device characterized by controlling printing pressure according to thickness.