JPS597053A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To cause an ink jet recorder to write good characters by such an arrangement wherein when electric power is supplied to the recorder, such ink droplets which are not related with printing and slightly changed in nature such as rise of viscosity, etc. are caused to distharge at a place other than printing space, and subsequent discharge of ink droplets is made smooth. CONSTITUTION:Electric power is supplied through switch SW and after a specified period of time has elapsed, 1 is sent to a signal line l TO. By this, a flipflop FF is set and an AND gate AG1 is opened. Next, when print signals are given through key input, etc., a timer TM is reset by a signal line lp and it causes a monostable multivibrator MM1 to operate through the AND gate AG1. By its output, the flipflop FF is reset and an AND gate AG2 opens and signal is given to a head driver PZD. By this arrangement, ink droplets are discharged during such a period of time while the monostable multivibrator MM1 is kept in 1 condition, and when it becomes 0, normal head drive control and discharge of ink droplets are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording apparatus, and particularly aims to improve ink ejection thereof.

The aperture of the inkjet nozzle in an inkjet recording device is very thin, approximately 1/10 mm, so if it is left unused for a long time, the ink in the area near the aperture that is in contact with the air will be affected by the external temperature and humidity. Under the influence of this, changes in viscosity and the like occur, and if normal printing operations are performed in this state, ink may not be ejected or the ejection direction may be greatly deviated. If you try to print graphics or character data under such conditions, some parts will not be printed at all and some parts will have characters and numbers printed on them, or characters and numbers with unknown or different meanings will be printed. It is expected that printing defects such as

In particular, in an inkjet recording apparatus, ink is easily affected by temperature, and the number of non-ejected dots and defective printed dots vary depending on the temperature, making it difficult to obtain good printing.

An object of the present invention is to improve the above-mentioned disadvantages of ink ejection with respect to temperature, and to improve the ink ejection, for example, even when the power is left off for a long time, or when the power is on and the printer is in a standby state for a long time. It is an object of the present invention to provide an inkjet recording device that can draw good characters, figures, etc. by ejecting ink into the inner grooves even when continuous printing is performed.

That is, in the present invention, when the power is turned on to the inkjet recording apparatus, the temperature at a location unrelated to printing, for example, the home position, is several dorats depending on the temperature at that time.
Ejection unrelated to printing such as 0 dots (hereinafter referred to as idle ejection) is performed to eject ink droplets with changes such as increased viscosity, and normal ejection is performed in subsequent printing.

In addition, in the present invention, when the printer is in the printing standby state with the power turned on, prior to printing after the time set by the timer has elapsed, a dry discharge of several dratles and 10 dots is performed depending on the temperature in the same manner as described above. Make sure to print properly.

The present invention will be described in detail below with reference to one drawing.

FIG. 1 shows an example of an inkjet recording apparatus according to the present invention. The carriage CA, which is integrated with the coil of the linear motor (not shown), is driven by this linear motor and moves back and forth, and during this movement, ink droplets are ejected from the inkjet nozzle N mounted on the carriage CA. It executes printing. PM is a permanent magnet for a linear motor, Yl is a bottom plate made of a magnetic material, and Y2 is a sliding shaft made of a magnetic material. In Figure 1, LB and I)B are
A light emitting diode and a phototransistor constitute a photointerrupter for Bohm position detection, respectively, and a shielding plate SB integrated with the carriage CA blocks the optical path between the light emitting diode LB and the phototransistor PB. The home position is detected by changing the output signal from the phototransistor PB. KP is a capping recovery mechanism that caps the nozzle N and sucks out the ink from the nozzle N when ink fails to be ejected due to dust etc. landing on the nozzle N, and corresponds to the nozzle position at the home position. There is. Furthermore, DI and D2 in the figure are buffers for buffering the contact impact of the carriage CA, and PL is a platen, and this platen PL is driven by a stepping motor SP.
and G2 to feed paper in the sub-scanning direction. The tank is a main tank for storing ink, and the ST is a sub-tank, and both tanks and ST are communicated through an ink tube Tl. P is a support member for the tube TI, which fixes the tube TI to the bottom plate Yl.

SS is a slit plate for detecting the position of the carriage CA in the main scanning direction, PC is a printed circuit board for ink nozzle control, and FL is a flexible wiring board for communicating No. 46 with the printed circuit board PC.

FIG. 2 shows an example of the electric circuit part in the present invention. Here, when the power is turned on from the switch SW, the print control unit PCT sends forward and reverse drive signals V and 3 of the motor (carriage), respectively. "0" and "■", and the carriage CA is driven in the opposite direction to move eight times toward the home position.

When the home position is detected by the phototransistor PH due to the movement, the motor drive voltage is lowered and the carriage CA is pressed and fixed against the damper DI.

Further, the home position detection output of the carriage CA by the phototransistor PB is output from the main control unit Ma by the signal 11n.
This signal is also transmitted to r, and the main control unit MCT sets the signal line ll@''1'' to the signal line ll@''1'', and sends this signal ''1'', that is, the power-on detection signal, to a monostable multi piper (hereinafter referred to as mono multi). input to MM2 to operate the monomulti MM2.The time constant circuit TC2 for setting the output time of the monomulti 2 is provided with a thermistor SR2 in consideration of the temperature. If the temperature is low, the output time width is made long, and if the temperature is high, the time width is made short.

The output signal of the monomulti MM2 is input to the AND gate AG3, and the AND gate AG3 is opened. anime) A
When G3 is opened, a pulse from the pulse generator PG is input to the inkjet head driver PZD via the OR gate OGl, and drives the head at a frequency determined by the pulse generator PG. Then, several dots or several tens of ink droplets are jetted depending on the temperature at that time, while the output of the monomulti IV'J2 is 1''.

The above is the dry ejection operation when the power is turned on.Next, the dry ejection during printing from the print standby state will be explained.

When the recording device is in the printing standby state after Kmm is entered by the switch SW, the timer "1"M in FIG. Output.

When the signal line ITO becomes "lI+", the flip-flop F
F is set, its output Q becomes 1'', and the AND gate ADl is opened.

When the print signal Pin is inputted in such a state due to manual input of the key, the timer TM is reset by the signal line lp and starts counting again, and the AND gate AD
Operate mono-multi MMI through Z. When the monomulti MMl operates, its output signal line 1pr+ is kept at '1' for a preset period of time by the time constant circuit TC1.
" is output. This set time is determined by taking temperature into consideration, as with the time constant circuit TC2, and a thermistor SR1 is provided. [E] shortens the time width.

When the output III+ is obtained from the monomulti output signal line Jpo, the flip-flop I"F is reset by that signal, and the AND gate AG2 is opened, so that the output of the pulse generator PG is sent to the head via the OR gate αil, as described above. As a result, several dots or several 10 dots of ink droplets are ejected for the time period when monomulti MMl is "1".

When the output of the monomulti MMI becomes '0', the AND gate AG2 is closed and the output of the pulse generator PG is no longer transmitted to the head driver PZD, and the head drive control and ink droplet ejection are performed using the normal print output signal PD. will be carried out.

Then, the next discharge after a certain period of time of timer N is as follows:
Print signal Pi after the time of timer 'N, which was restarted after being reset by the previous print signal Pin, has elapsed.
It operates by inputting n. Naturally, if the print signal Pin is input before the elapse of a certain time based on the timer system, the timer TM is only reset and restarted, and does not affect ejection.

Note that this idle ejection from the printing standby soft stool is performed toward the capping mechanism KP at the home position in the same manner as described above since it is in the standby state.

In addition, the time settings for the reference temperature of Mono-Multi MMI and Mono-Multi 2 are set to different values, and the number of ejections is different between dry ejection when the power is turned on and empty ejection from the print standby state, and each state It is preferable to perform idle ejection according to the following conditions.

As is clear from the above, according to the present invention, by controlling dry discharge according to temperature changes, printing can be performed according to the temperature situation after being left in the power-off state for a long time, and printing can be performed according to the temperature situation in the printing standby state. When printing, dry ejection is performed at the capping part at the home position according to each temperature, ink whose viscosity has increased, etc. is ejected, and the ejected ink is contained within the cap, thereby preventing the interior of the feeder from becoming dirty. Necessary data can be printed reliably, defective printing such as missing characters or irregular printing can be prevented, and good printing can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the appearance of an example of an ink jet recording apparatus of the present invention, and FIG. 2 is a circuit diagram showing an example of the configuration of an electric circuit portion of the ink jet recording apparatus of the present invention. CA... Carriage, N... Inkjet nozzle, PM... Permanent magnet for linear motor. Yl...bottom plate made of magnetic material, Y2...sliding shaft made of magnetic material, LB...light emitting diode, PB...phototransistor, SB...shielding plate, KP...gear rubbing recovery mechanism, nl , D2...
Carriage CA contact price 5$ buffer, PL... platen, SP... stepping motor, Gl, G2... gears,
r~Tan...Ink storage tank, ST...Sub tank, Tl...Ink tube, P...Tube TI support member, SS path slit plate, PC...Printed circuit board for ink nozzle control , FL...F1/xypul wiring board, PCT...print control section,
Ml”...Motor (carriage CA) forward direction drive signal, MB...Motor (carriage CA) reverse direction drive signal, 1,.14.#p, JT□, lpo...Signal line, MCT ...Main control unit, MMi, MM2
・・・Monostaple multivibrator, TCLTC
2...Time constant circuit, SRI, SR2...Thermistor, AGE, , A, G2. AG3°゛°and gate,
OGl...or gate PG...
・Pulse generator, PZD...Inkjet head driver, SW,...Switch, TM
,,,Timer, CPG...Clock generator, FF...Flip-flop, Pin...Print signal, PD...Print output signal. Patent applicant Canon Co., Ltd.

Claims (1)

[Scope of Claims] 1) A means for generating a first output determined according to the ambient temperature, and a means for ejecting ink unrelated to printing to a location other than the printing section by an amount corresponding to the first output. An inkjet recording device characterized by comprising: means for causing the recording to occur. 2. In the inkjet recording apparatus according to claim 1, means for detecting power-on, and generating a second output determined according to the ambient temperature in response to the power-on detection output from the means. and means for ejecting ink unrelated to printing in an amount corresponding to the second output at a location other than the target printing section. 3) An inkjet recording apparatus according to claim 2, wherein the first and second outputs are different from each other. 4) The inkjet recording device according to any one of claims 1 to 3, wherein a location other than the printing section is a capping recovery mechanism provided at a home position.