JP2637676B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for discharging ink regardless of data to be recorded.

[0002]

2. Description of the Related Art An ink jet recording apparatus has an ink jet nozzle formed from a thin glass tube or the like. By applying a control signal to a piezoelectric element (hereinafter, referred to as piezo) fitted around the ink jet nozzle, for example, There is a type in which a droplet having a diameter of about 80 μm is ejected in the form of a droplet at an initial velocity of 4 to 8 m / s, and collides with a printing paper to perform recording. In an ink jet recording apparatus equipped with an ink jet nozzle having this type of structure, the ink is ejected only during printing, and the ink is not ejected during non-printing. The ink evaporates from here, and the viscosity property of the ink changes. The ink used for such an ink jet varies depending on its use, but its characteristics are greatly changed by the influence of external temperature and humidity. In particular, in an on-demand type ink jet apparatus, when the ink jet apparatus is not used for a long time, the viscosity of a portion such as a discharge port which is in contact with air increases. In general, when used in an office or the like, the viscosity after a certain period of time increases, and in such a state of printing, the ink may not be ejected or the ejection direction may deviate significantly from the normal position. In particular, when dealing with money or the like, erroneous printing is dangerous, and characters or numbers that are not printed at all, or characters or numbers with unknown or different meanings may be used, and some measures need to be taken.

[0003] Conventionally, there is also known an example in which a preparatory ejection irrelevant to printing (hereinafter referred to as idle ejection) is performed immediately after a print command as in Japanese Patent Publication No. 52-2780.
In this case, there is a disadvantage that the processing speed is slow in the whole apparatus.

Japanese Patent Publication No. 52-863 discloses a technique for performing idle discharge every time a timer elapses.

Japanese Patent Application Laid-Open No. 50-57518 discloses a technique for intermittently ejecting ink when recording is stopped.
No. 991 discloses a technique of stopping ink ejection for preventing drying in response to a warning signal based on detection of ink leakage or the like in an ink supply system. Also, 52-42
No. 031 discloses a technique for adsorbing ink droplets ejected at the time of preliminary ink ejection with respect to ink ejection using an adsorption band.
No. 1,373,366 discloses a technique for performing test injection according to the degree of drying in order to prevent adverse effects due to drying of the nozzle.

Japanese Patent Application Laid-Open No. 54-9928 discloses that when ink runs out due to drying of a nozzle, a recovery operation is performed at a predetermined position, the head is moved to the position where the ink runs out, and then a print signal is output. Japanese Patent Application Laid-Open No. 54-48551 discloses a technique for applying a greater ejection driving force than usual at the time of startup in order to prevent adverse effects due to nozzle clogging. Discloses a technique for ejecting ink liquid from all nozzles after a predetermined time has elapsed.

[0007]

However, various improvements have been made, but each has its advantages and disadvantages.
There is still room for improvement.

[0008]

In view of the above, it is an object of the present invention to provide an ink jet recording apparatus in which a recording operation has not been performed for a predetermined period of time so that a high-quality recording can be performed. An object of the present invention is to provide an efficient ink jet printing apparatus by performing printing and receiving print data using the time.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an ink jet recording apparatus for ejecting ink irrespective of data to be recorded. Determining means for determining the amount of ink to be ejected irrespective of the data to be printed; and specifying means for ejecting ink irrespective of the data to be printed based on the determination by the determining means. Receiving means for receiving data to be recorded even during the specified amount of time. According to the present invention, with the above-described configuration, a predetermined amount of ink irrespective of data to be recorded is ejected in a predetermined amount so that high-quality recording can be performed by an inkjet recording apparatus in which a recording operation has not been performed for a predetermined time, and the time is used. By receiving print data, an efficient ink jet printing apparatus can be provided.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. Normally, the viscosity after a certain period of time when an ink jet recording apparatus is used in an office or the like can be experimentally predicted, but in this embodiment, after the certain period of time, data or a command is received. That is, a predetermined amount of ink whose viscosity has been increased is discharged (hereinafter, referred to as idle discharge).

Here, the data or command may be, for example, a command of the idle discharge itself or a command in the ASCII code which is not directly related to printing, such as "LF" or "NULL". Note that a strobe signal described later is a signal for validating and transferring commands and data on the bus line when transmitting these data and commands.

As described above, based on the data or command transferred after the printing operation has not been performed for a predetermined period of time, for example, the specific code "NULL" code is first received, and the idle discharge is executed. If print data is received and printed in parallel during execution, the print speed is improved. Even in the case of non-use for a long time, if a code or a command such as "LF" or "NULL" which is not particularly related to printing is received, idle discharge is executed at that time. Only the ink consumption is smaller than in the case of the idle ejection. Also, in the case where idle printing is performed in response to a print command after non-use for a long time, if it is longer than the expected elapsed time, the number of idle discharging dots may be insufficient, and ejection failure is not solved Such a situation can be dealt with by performing idle ejection when data or a command is received after a predetermined period of time, as in the present invention.

A recording apparatus according to an embodiment of the present invention will be described with reference to FIGS. The recording head, that is, the carriage CA having the ink jet nozzles N is driven by a linear motor. The linear motor forms a closed magnetic circuit by the members of the permanent magnet PM, the magnetic plate Y1, and the magnetic sliding shaft Y2, and supplies a current to the coil C wound around the slidable coil bobbin CB so that the framing is performed. The carriage CA integrated with the recoil bobbin CB is driven according to the left-hand rule. The reciprocating motion of the carriage on the sliding axis Y2 is performed by changing the direction of the current flowing through the coil C. A scale plate, for example, a scale plate OS made of a non-magnetic material is vertically fixed to the magnetic plate Y1 together with the sliding axis Y2. On the carriage CA, a coil bobbin CB of the coil C, a sub-tank ST for supplying ink to the inkjet nozzles N and N, a light emitting element such as a photodiode LE, a light receiving element such as a phototransistor PT, and a printed circuit board PC for connecting a flexible wiring board FL are fixed. In addition, a photodiode LB at the home position and a shielding plate SB for blocking the phototransistor PB are integrated. At one end FL1 of the flexible wiring board FL, terminals C1 and C2 of a coil C, a piezo terminal (not shown) serving as a driving source of the inkjet nozzle N, a terminal LET of a photodiode LE, and a terminal PTT of a phototransistor PT are electrically and mechanically provided. Connected. The other end portion FL2 of the flexible wiring board FL is fixed together with the ink supply pipe T1 by a holding plate P. The ink supply pipe T1 is guided rearward between the permanent magnet PM and the magnetic plate Y1 by using a magnetically necessary air gap.
Are connected to supply ink to the sub tank ST. The scale plate OS is composed of the photodiode LE and the phototransistor PT.
Between the recording head N and the recording head N. This saves space and reduces size. Carriage CA
The infrared light emitted from the photo diode LE along with the movement of the photo transistor PT has a slit portion SS and a slit of the same pitch as the slit portion SS, and the receiving slit PT attached to the light receiving portion of the photo transistor PT turns on and off the photo transistor PT.
The FF is repeated to generate a timing pulse TP as shown in FIG. The timing pulse TP detects the speed and position of the carriage CA during re-carriage scanning, and controls the speed, the ink jet nozzles, and the paper feed pulse motor SP. Further, a shielding plate SB accompanying the movement of the carriage CA.
The phototransistor PB at the re-home position is also turned on and off by the movement of, and the presence or absence of the carriage is instructed at the home position. If you want to print one line,
The characters are composed of a dot matrix, the carriage CA scans, the position is detected by a timing pulse TP, and a voltage is applied to the piezo of the ink jet nozzle at a predetermined position to print and discharge small ink droplets. Paper PP
1 dot line printing. When the printing of one dot line is completed, an operation of rotating the paper feed pulse motor SP by one dot pitch and simultaneously returning the carriage CA to the home position is performed. Confirmation of the home position is performed by the phototransistor PB. In the paper feed, the rotation of the pulse motor SP is transmitted by a motor shaft gear (not shown) by a reduction gear G1 and a gear G2. Last gear G
Reference numeral 2 is fixed to the axis of the platen PL, and can feed a predetermined amount of paper in the row direction. This operation is repeated, and when printing of a predetermined dot line (for example, 7 lines) in the row direction is completed, the platen PL is rotated by a predetermined amount of the row by the pulse motor SP, and printing of one row is completed. After printing, the inkjet nozzle N is moved to the position of the cap KP and stopped. This cap is nozzle N
A function of sucking the leading end of the ink jet nozzle, thereby preventing the ink jet nozzle from being clogged, dried, meniscus receding, and the like. In addition, the cap KP performs idle discharge irrelevant to printing according to the present invention described later.

D1 and D2 are collision dampers made of foam or the like, which soften the collision of the carriage CA and prevent ink leakage from the nozzles, meniscus retreat, and the like. Further, since the sub-tank ST is arranged so as not to come into direct contact with Y1, D1, etc., the impulse force is weakened, and foaming in the sub-tank is small.

Further, since a rotary motor is not used for driving the carriage, no gear, link, rack, etc. are required, and a ratchet, plunger, etc. are not used for paper feeding, so that an extremely quiet recording apparatus can be constructed. The sub tank and one end FL1 of the flexible wiring board FL are provided on the carriage.
Is mounted, and various electric parts are connected to it.
It can be manufactured inexpensively, can be freely moved by a flexible wiring board, and can have various features such as being simple because the ink supply pipe to the sub tank on the carriage is locked at one place. It is.

In the apparatus of this embodiment, the scale plate OS is provided with a slit SS as shown in FIG. 3, and serves both as a control for confirming the position and a control for stabilizing the speed.

That is, as shown in FIG.
The speed is adjusted until the carriage CA starts moving from the initial position HO and counts eight slits SS, for example.
The printing of the digits is started, the printing of one digit is completed by 5 slits of 8 to 12, the two slits of 13 and 14 are made blank with the adjacent digits, and thereafter, this is repeated. AS is an approach slit for detecting a printing start position, CS is a character slit, and BS is a plank slit. The carriage movement speed is also stabilized by these slits and their intervals. The position where the carriage CA starts to move from the home position and the signal of the phototransistor PB changes from OFF to ON is provided with a shielding portion corresponding to several slits in consideration of the position and speed variation. In addition, the power supply voltage for driving the linear motor has two values, and is driven at a normal voltage during a normal printing operation, and is constantly switched to a voltage lower than the normal voltage when the carriage is pressed to the right end. That is, when the power is turned on, first, the carriage CA is driven in the BACK direction (the right end direction in FIG. 1),
When it is confirmed by the output signal from the phototransistor PB that the carriage CA has moved to the home position, the motor drive voltage is switched to a low voltage, the carriage speed is reduced, and the carriage is pressed against the damper D1 to make contact with the cap KP. The carriage CA is fixed at this position where the inkjet nozzle N mechanically corresponds. Naturally, when the carriage CA has been at the home position for a long time, the motor drive voltage is immediately switched to a low voltage, and the print head enters a waiting state. Also, after the printing of one line is completed, if the carriage CA returns in the BACK direction and the arrival at the home position is confirmed, the motor drive voltage is switched to a low voltage as described above, and the damper D is switched.
1 to fix the position of the carriage CA, so that the nozzles can be reliably recovered by ejecting, protecting the head, and forcibly suctioning, regardless of printing toward the cap KP.

FIG. 5 shows an example of a control circuit of the present apparatus.
The lead wires FF, FB, FV, FT, FP, FE are integrally formed as shown as a flexible wiring board FL in FIG. 1 to facilitate movement of the carriage CA. In FIG. 5, when the power is turned on to the apparatus, the control unit CC resets the flip-flop F1, the number-of-stages counter 7C, and the speed control unit SC by setting the signal line 12 to 0 at a fixed time, TP separation circuit TB
Is cleared, and the power supply voltage switching signal line lsV is set to 0.
Then, the transistor TRS is turned off, the normal voltage is applied to the motor drive voltage, and the carriage CA is moved to the home position. This means that the coil drive signal output line 1F is set to 0 and 1B to 1 to drive the carriage CA in the BACK direction, that is, the home position direction.

After the drive in the BACK direction, the control unit CC detects whether or not the re-carriage CA is at the home position by the signal line lTR indicating the home position.

When the carriage CA is not at the home position, it moves to the home position while controlling the speed by the speed control unit SC by driving in the BACK direction, and is moved by the shielding plate SB integrated with the carriage CA. The phototransistor PB which has been turned on by the photodiode LB is turned off (0 → 1). This signal is
It amplified the TR in through connexion amplifier AP2, Li controller CC by the output signal line l _BC detects that the carriage CA is in the home position.

In response, the control section CC changes the signal line 1SV from 0 to 1 and turns on the transistor TRS.
Then, the voltage of the Zener diode ZD2 is brought into a short-circuit state. As a result, the voltage LMV supplied to the remotor driver unit MD is switched to a low voltage, and the carriage CA is maintained in a state where the motor drive signal lines 1F and 1B are kept at 0 and 1.
To the right edge.

Further, when the carriage CA is at the home position from the initial state, the phototransistor PB is in the OFF state (state of 1). , Pressed against the rightmost foam Dl. Then, the ink jet nozzle N mounted on the carriage CA is stopped at the home position corresponding to the cap KP.

The timer TM in the figure is a clock generator C
The PG performs a re-count operation, and outputs 1 to the signal line 1 _TO when a preset time elapses. When the signal line 1 _TO becomes 1, the flip-flop FTM is set and the output Q
Becomes 1, and the AND gate AD1 is opened. Further, the output signal of the flip-flop FTM simultaneously transmits to the control unit CC that the idle discharge irrelevant to printing is performed by the signal line _lcom output when the subsequent specific code is received. Now, as shown in FIG. 7, there is no printing operation, the carriage CA is waiting at this home position, the set time of the timer TM has elapsed, the signal line _TO becomes 1, and then a specific code, for example, through the signal line BUS. When the NULL code is input, the decoding circuit XRL
And the signal l _com is output to the signal line M. This specific code detection signal is output from the opened AND gate AD.
1, the one-shot multivibrator OST is operated, and at the same time, the timer TM is reset and restarted. When the one-shot multivibrator OST operates, its output signal line l _po outputs 1 for a predetermined period of time. When the signal line l _po becomes 1 and is output, the timer TM is reset and restarted by the signal via the flip-flop FTM and the OR gate OTM, and when the AND gate AD2 is opened,
The output of the oscillator OSC is input to the pulse increase setting circuit DS and the piezo drive circuit PD via the OR gate ORT to drive the piezo PZ at a frequency determined by the oscillator OSC, and the output of the one-shot multivibrator OST is set to 1
That is, the ink droplets are ejected only during the period of time.
When the output of the one-shot multivibrator OST becomes 0, the AND gate AD2 is closed, and the oscillator OSC
Is not transmitted to the piezo drive circuit. The output signal line l _po is also transmitted to the control unit CC. The falling of this signal causes the control unit CC to detect the end of the idle ejection, and thereafter, when print data is received, performs a printing operation. to go into. The idle discharge after the elapse of a predetermined time of the next timer TM is operated by the input of the specific code-match signal COM after the elapse of the time of the timer TM reset and restarted by the output signal of the one-shot multivibrator. If the print command signal Pin is input before the predetermined time elapses by the timer TM, the timer TM restarts the reset via the OR gate OTM. As a matter of course, idle discharge is not executed by the specific code-match signal input before the time of the timer TM elapses.

As described above, the location of the idle discharge in the above is irrelevant to the printing, and a specific place is required to keep the inside of the apparatus from being contaminated with the discharged ink. In this embodiment, however, FIG. As shown, a shielding plate S in which the ink jet nozzle N has a home position portion, that is, a phototransistor PB and a photodiode LB integrated with the carriage CA.
B is at a position where it can be interrupted, and at that position, the cap KP of the nozzle corresponds to the ink jet nozzle N and performs the above-described ejection.

The above description is of idle discharge when a specific code is received. FIG. 6 is a circuit diagram of idle discharge when a strobe signal S is received.

In the previous example, the one-shot multivibrator OST operates when the specific code detection signal is output after the set time of the timer TM has elapsed, and the idle discharge is performed for the set time. The idle discharge is performed on the specific code detection signal line using, for example, a strobe signal S used for transmitting a command or data.
That is, the timer TM is the same as the idle discharge according to the specific code.
The one-shot multivibrator OST is operated by the signal S through the inverter iSB by the manual operation of the strobe signal S after the set time elapses, and the idle discharge is executed as described above, and the timer TM is reset and restarted. .

As described above, upon receiving a specific code or a strobe signal after a predetermined period of non-use by the above-described discharge control, the ink whose viscosity has increased at the cap portion at the home position is discharged without discharge. The ink can be stored in the cap and the necessary printing operation can be performed immediately without soiling the inside of the device. Printing can be obtained. Also, as shown in FIGS. 7 and 8, after the idle state for a long period of time, if a specific code, for example, a NULL code or a strobe signal, is used during idle ejection, the next data to be printed is received in parallel to improve the printing speed. Also, even if the unused time is longer than the expected non-use time, the idle discharge is performed by inputting a code or strobe signal irrelevant to printing, and the number of empty discharge dots may become insufficient. Can be dealt with.

[0028]

According to the present invention, a predetermined amount of ink irrespective of data to be recorded is discharged so that high-quality recording can be performed by an ink jet recording apparatus in which a recording operation has not been performed for a predetermined time.
By using the time to receive the print data, an efficient ink jet printing apparatus can be provided.

[0029]

[Brief description of the drawings]

FIG. 1 is a perspective view of an example of the present invention.

FIG. 2 is a sectional view of an example of the present invention.

FIG. 3 is a diagram illustrating an operation of an example of the present invention.

FIG. 4 is a diagram illustrating an operation of an example of the present invention.

FIG. 5 is an example of a control block.

FIG. 6 is another example diagram.

FIG. 7 is a waveform diagram for explaining the operation of FIGS.

FIG. 8 is a waveform diagram for explaining the operation of FIGS.

[Explanation of symbols]

 N inkjet nozzle BUS bus line XRL decoding circuit S strobe signal

Claims (1)

(57) [Claims] 1. An ink jet recording apparatus for ejecting ink irrespective of data to be recorded, a discriminating means for judging whether or not a recording operation has not been performed for a predetermined time, and ejecting ink irrespective of data to be recorded. Means for designating an amount to perform, and reception of data to be recorded even during a period in which ink ejection irrespective of data to be recorded based on the discrimination by the discrimination means is performed by the amount designated by the designation means. An ink jet recording apparatus comprising: receiving means for performing