JPH0639179B2 - Recording device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a recording apparatus, and more particularly to a recording apparatus that records using an electro-heat exchanger.

(Prior Art) As a recording device, a recording device is known in which a drive signal is applied to an electric-heat exchange element to perform recording by utilizing heat generated by the electric-heat exchange element. In such a recording device,
The electric-heat exchanger is composed of a minute heater.

(Problems to be Solved by the Invention) Since the electric-heat exchanger is composed of a minute heater, it has a problem that it has a short life and is easily broken.

Therefore, the inventor of the present application has conducted studies to clarify the cause of shortening the life of such an electric-heat exchanger and the cause of disconnection. As a result, an unexpected abnormal drive signal that is generated in a cycle shorter than the cycle of the normal drive signal given to the electric-heat exchanger may be applied to the electric-heat exchanger, and the predetermined frequency as a whole. It has been clarified that the cause is that the above excessive drive signal is applied.

Therefore, the present invention prohibits application of an unexpected abnormal drive signal other than the normal drive signal to the electric-heat exchanger of the recording head, prevents the electric-heat exchanger from being damaged, and has a long life. The purpose is to obtain a highly reliable recording device.

(Means for Solving the Problems) A recording apparatus according to the present invention that achieves the above object is a recording apparatus that performs recording by utilizing heat generated by an electro-thermal converter,
Supply means capable of supplying a drive signal of a predetermined cycle to the electric-heat exchange body, and a predetermined means between the end of supply of the drive signal to the electric-heat exchange body and the start of supply of the next drive signal. And a prohibiting means for prohibiting the supply of the drive signal from the supplying means to the electric-heat exchanger during the time counting of the predetermined elapsed time by the time measuring means. It is characterized by

Further, the supply means supplies a drive pulse having a regulated pulse width.

Further, when the predetermined elapsed time is t, the predetermined cycle is T, and the pulse width of the drive signal is tp, t <T
-Tp.

(Example) The present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of the present invention. 1 is a counter, 2 is an SR flip flop, 3 is a JK flip flop, 4 is a monostable multivibrator (hereinafter referred to as monomulti), 5. 6a to 6n are AND gates, 7a to 7n are transistors, 8 is a print head, and 9a.
9n are heaters.

Now, when the print command pulse ▲ ▼ enters the set input S of the S-R flip-flop 2, the S-R flip-flop 2
Is set and the output Q1 becomes H level and is applied to the J input of the JK flip-flop 3. On the other hand, the reference clock E,
The frequency is divided by the counter 1, and the cycle is just the heater 9a-
A continuous pulse 11 having a pulse width (tp) of a pulse applied to 9n is supplied as a clock input CK of the JK flip-flop 3. The JK flip-flop 3 is set at the rising edge of this clock 11, and the output Q2 becomes H level and ▲ ▼ becomes L level. This .delta. Is input to the reset input R of the SR flip-flop 2, the SR flip-flop 2 is reset, and the output Q1 changes to the L level. Therefore, at the next rise of l1, the JK flip-flop 3 changes its state, and the output Q2 becomes L level and ▲ ▼ becomes H level.

After that, if there is no signal ▲ ▼, since the J-K flip-flop 3 has the J input at the L level and the input at the H level, the state does not change even if 11 is input to the CK input, and the output Q2 is at the L level. ▲ ▼ keeps H level.

As described above, the output Q2 of the JK flip-flop outputs one pulse having the same width as 1 for one strobe pulse {circle around (1)}.

On the other hand, the output Q2 of the JK flip-flop 3 is input to the monomulti 4 and its output l
Keep 2 at Q level.

This l2 and the above-mentioned Q2 are input to the AND gate 5, and only when the respective inputs are at the H level, the output l
3 becomes H level and AND gate 6a for head drive
6n is input as one input. The AND gate 6
Only when the print data D1 to Dn are input to the other inputs of a to 6n and there is data, the output of H level is added to the transistors 7a to 7n and the transistors are turned on to turn on the heater 9
The head driving power source V _{H is} energized to a to 9n, and printing is performed by the thermal energy.

FIG. 2 is a timing chart for explaining the operation of FIG. The time t for keeping the output 12 of the mono-multi 4 at the L level is t <by the time T of the maximum printing cycle and the print pulse width tp.
When T-tp is set to hold, the above operation is repeated in a normal cycle to perform normal printing.

Now, a state when a plow having a frequency higher than the normal frequency is input will be described with reference to the timing chart of FIG.

At the first ▲ ▼ input, AN
The output 13 of the D gate 5 is at the H level for the time of tp.
Next, when ▲ ▼ is input again in a time shorter than the time t set in the monomulti 4, the output Q2 of the JK flip-flop is output in the same manner as in the normal time. However, at this time, the output 12 of the mono-multi 4 remains at L level, and the output 13 of the AND gate 5 becomes L level, so that no pulse is applied to the heaters 9a to 9n.
Further, the output Q2 at this time causes the monomulti 4 to be reset again so as to keep the output at the L level for a certain time t, so that no matter how many ▲ ▼ pulses are input after the time t, the AND gate is input. The output 13 of No. 5 is held at L level, and no pulse is applied to the heaters 9a to 9n. In the pulse after the time t, since the output 12 of the monomulti 4 is at the H level, the AND gate 5 is at the H level for tp time as usual, and the heaters 9a to 9n are energized. It

As described above, a pulse having a cycle shorter than the set time t of the monomulti 4 does not appear as the output 13 of the AND gate 5 of the final heater drive, and 13 is at least a cycle longer than the set time t of the monomulti 4. Pulse appears, and its width does not exceed the period of the output 1 of the counter 1.

(Effect) As described above, according to the present invention, it is prohibited to apply an unexpected abnormal drive signal other than the normal drive signal to the electro-heat exchanger of the recording head, and
It is possible to prevent the heat exchanger from being damaged, and to obtain a highly reliable recording device having a long life.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a timing chart of the circuit during normal operation, and FIG. 3 is a timing chart of the circuit during abnormal operation. 1: Counter 2: S-R flip-flop 3: J-K flip-flop 4: Monostable multivibrator 8: Printing head 9: Electric-heat converter (heater)

Claims (3)

[Claims] 1. A recording apparatus for recording by utilizing heat generation of an electro-thermal converter, supplying means capable of supplying a drive signal of a predetermined cycle to the electro-thermal converter, and the electricity of the drive signal. -Timer means for measuring a predetermined elapsed time until the start of supply of the next drive signal in response to the end of supply to the heat conversion body, and during the measurement of the predetermined elapsed time by the time measuring means, A recording device, comprising: a prohibition unit that prohibits supply of a drive signal from the supply unit to the electro-thermal conversion body. 2. The recording apparatus according to claim 1, wherein said supplying means supplies a drive pulse whose pulse width is restricted. 3. When t is the predetermined elapsed time, T is the predetermined cycle, and tp is the pulse width of the drive signal, t <
The recording apparatus according to claim 1 or 2, wherein the recording apparatus is T-tp.