JPS5916936B2 - printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device such as a calculator, and more particularly to a printing device that can print in a plurality of positions by switching the direction of hammer movement.

FIG. 1 is a cross-sectional view of one embodiment of the present invention, where DT is a small desk calculator, its keys are set, DS is a numeric display made of liquid crystal, etc., CD is a type drum made of rubber, etc., and C is its type. Group, engineering R is an ink roller that supplies ink to C, H is a drum C
If you switch the position of the hammer housed in O← as shown in H', you can print on the paper P2 on the desk.

KA is a paper cassette containing roll paper P1, and calculator DT
It is configured to be detachable. S is a switch for detecting the attachment/detachment state of the cassette KA. For example, when the cassette KA is loaded, it is turned on to hold the hammer H at the solid line position, and when it is removed, it is turned off and held at the dotted line position. Alternatively, even if it is in the loaded state, it can be switched to the H' position and used by an instruction from the key. KB is a key input circuit, CAL is an arithmetic unit, and PC is a print control circuit. Figure 2 shows the first concrete example.
This is an example circuit diagram showing an example of a case where a DC motor is used as a drive source for rotating a type drum.

In the figure, L is a lamp, DD is a disk for generating a type position signal, Ca is a hole corresponding to the type position, hl is a hole that informs the PC of the first home position, and 2 is a hole that informs the PC of the second home position.
It is a hole that lets you know. CD, Re1D, and Re2D are each Ca
. R indicates the reset input of CC. HS is an electromagnet position for switching the position of the hammer H, A1 and A2 are AND gates, 11 is an inverter, and ORI is an OR gate. When the cassette KA is loaded, switch S is on and OR gate O
It is assumed that the output of RI is at a low level.

Therefore, the AND gate A1 is open, A2 is closed, and the electromagnetic device HS is not energized, so the hammer H is at the solid line position in FIG. 1, and as is well known, the hammer H
The rubber type C is brought into contact with the platen PL on the force set KA side by protruding to the left, and printing is performed on the roll paper P1 located therebetween. Next, in response to a hammer position switching command from key K, signal PS is set to high level, and AND gate A1 is closed and A2 is opened. Also, energize HS and move the hammer to H/
Switch to the dotted line position. As a result, the home position is switched from h1 to H2, and the control circuit PC determines this and resets the character counter CC to change the count contents.
For example, in the illustrated example, by shifting three characters from when hl is the home position, H2 can be treated as the home position. Therefore, for example, when the AND gate A2 is open, when CC counts three characters, it is set and reset from 1, and the characters are correctly counted and printed on P2 with H2 as the home position. When the force set KA is removed as described above, printing is similarly performed on P2 at the position of the hammer H'. In the example shown in Fig. 2, a special hole H2, detector H2D, etc. are required to control switching of the home position, but in the second embodiment shown in Fig. 3, switching is performed with one detector H1D as usual. This is an example of controlling.

In the figure, F1 is a flip-flop, KT is a counter that counts character pulses, and DK is a decoder that detects only a specific count value, for example, 3, of the counter KT.

When the force set KA in FIG. 1 is loaded, the hammer H is at the solid line position as described above, and the AND gate A3 is open and A4 is closed, so the character counter C
C performs the same operation as the normal type drum printer operation in that the output signal from the detector HID at the home position hl is passed through the AND gate A3.

When AND gate A3 is closed by print switching command signal PS or force set attachment/detachment signal S and A4 is opened, CC is reset according to the output timing from AND gate A4. That is, since the character pulse CA after the flip-flop F1 is set by the output of HID passes through the AND gate A5 and is counted by the counter KT, the specific value decoder DK outputs an output that detects 3, for example, and the AND gate Applied to A4.

As mentioned above, in this case, AND gate A4 is open, so immediately after CC counts 3, CA starts counting again from 1 to reset. Therefore, the type position is shifted by 3, that is, the same state as when the second home position H2 in FIG. Ru. 4 and 5 are diagrams of third and fourth embodiments in which a pulse motor PM is used instead of a DC motor. pulse motor PM
As is well known, when using , there is no need to detect the type position.
The type and position of printed characters can be detected by counting the pulses SP that drive the pulse motor. Therefore, printing is normally possible with just one detector at the home position, and in the case of the example in Figure 4, the detectors at the home positions Hl and h2 are provided, similar to the example in Figure 2, and the home position Similar to the previous example, this embodiment can be realized with a simple configuration that only changes the reset timing of the character counter CC depending on the switching of the positions H1 and h2.

The example in FIG. 5 is similar to the example in FIG. 3, and is an example in which printing position switching is performed using one detector HID, and its operation is the same as in the example in FIG. 3.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an example of a control circuit thereof, and FIGS. 3, 4, and 5 are examples of other circuits. CD: Type drum, H: Hammer, Pl, P2: Printing paper.

Claims (1)

[Claims] 1. A type drum having a type group around it, a hammer housed in the type drum, and a first home position signal detected when the hammer is set at a first position; 1
and a control circuit that detects a second home position signal and controls printing when set to a second position different from the position of , and is configured to be able to print on printing paper at different positions. printing device. 2. The printing device according to item 1, wherein the type drum is coated with ink from an ink roller.