JP2731153B2 - Ink jet recording device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ink jet recording apparatus,
Apparatus for digital image processing of color images, for example, digital
Tal color copier, color image scanner, camera
Inkjet recording suitable for color printers, etc.
It concerns the device. [Prior art] Recording by discharging ink from an ink jet recording head
In an ink jet recording apparatus that performs
The conventional control unit of the side is configured as shown in FIG. 9, for example.
I was That is, in FIG.
It is a sequence controller that controls, for example, a microphone
This is a control device in the form of a computer. 202 is the head
Driver circuit, 203 indicates an inkjet recording head
The driver circuit 202 receives the video data VD and the video clock.
D latch 205 that receives clock VCK and inverts clock VCK
Inverter 206, and a signal of a predetermined width according to its inverted signal.
One-short multivibrator 207 for output
And a comparator to which the output pulse and the reference voltage are supplied.
Heater 208 and the logic power line 213
3 ends not to fall before the drive power supply line 214 of 4
And a backflow prevention diode 210.
Has been established. In addition, the ink jet head 204 has an output of the D latch 205
AND gate 2 supplied with the output of comparator 208
11 and the output transistor 212 receiving the AND output
And a head heater driven by the transistor 212
-204. 216 and 217 are socket 218 and power switch 2
For example, AC100V commercial power is supplied via 15
Switching level to supply 5.8V and 26V DC power
It is a regulator. 5.8V output by power supply 216
The voltage is reduced to 5.0 V via the stop diode 219,
Is supplied with power. 26V output from power supply 217 is head
Power is supplied to the heater 204 at the time of discharge, and three more
This is supplied to the child regulator 209. 220 is a runaway detection circuit of the sequence controller 201.
Sequence controller 201 periodically
Clock 222 is output within a certain time
Is detected and reset to the sequence controller 201.
The reset signal 223 is supplied and reset. Also, the signal H
ENB is a head discharge enable signal and AND gate 2
It is not necessary to gate VD and VCK by 21 to perform the discharging operation.
No signal is input to the head driver circuit 202.
It has been, Here, as shown in the time chart of FIG.
The data VD sent in synchronization with the clock VCK is
The output is latched by the D latch 205 of the driver circuit 202, and the output is
Input to AND gate 211. On the other hand, clock VCK is
One-shot multi-buy after input to converter 206
A pulse having a constant pulse width,
A pulse having a width T = 10 μsec is set, and the comparator 208
The waveform is shaped by comparing with the reference voltage and
Is entered. AND gate 211 outputs a transistor
And connected to the output of the AND gate 211.
To apply power to the head heater 204 and
Bubbles are generated in the ink, and the force ejects the ink.
Let out. When the power switch 215 is turned on, the power
5V output rises first, or 26V of power supply 217 first
Rises in the circuit capacitance or impedance
Cannot be specified due to factors such as Therefore, for example, 5V output
If 26V output rises before the rise, 3 terminals
26V is converted to 5V by regulator 209 and
The transistor 212 is turned on because the power is supplied to the source line 213.
And the current does not flow through the head heater 204 for the specified time or longer.
Control. Similarly, turn off the power switch 215
In this case, it is possible to specify which output falls first.
Since there is no such signal, it is controlled by the three-terminal regulator 209.
That is, the power switch 215 is turned off, and the power line 213 is driven.
The voltage of the dynamic power supply line 214 begins to drop.
The output from the three-terminal regulator 209 is a diode 210
Power supply line 213, the voltage of
, So that the AND gate 211 and the transistor 212 are
Works fine. When the descent further continues, the drive power
Source line 214 outputs 5V to the output of 3-terminal regulator 209
It becomes about 8 V that cannot be done, and the power supply
IN 213 can no longer hold 5V and AND gate 211,
The transistor 212 starts malfunctioning. But at this time
Since the power supply line 214 has a voltage of about 8 V,
For example, malfunction of driver circuit 202 and AND gate 212
Even if the heater 204 is energized due to
It is controlled so that there is not. [Problems to be Solved by the Invention] However, in this conventional configuration, the power switch
26V is always supplied to drive power supply line 214 when 215 is turned on.
The sequence due to disturbances such as noise.
Controller 201 runs away and AND gate 221 malfunctions
Or the nozzle enters the logic power supply line 213
As a result, the logic section may malfunction. Another one
Generally, the head driver circuit 202 and the inkjet head 203
Are often placed at a distance from the
Since they are connected by cables, connectors and cables
It is easy to spread disturbance in the middle of
The heater 204 could be destroyed. An object of the present invention is to solve such a problem and to provide a system starter.
Prevents malfunctions caused by disturbances during
Ink cartridge designed to prevent inconveniences such as disconnection
Jet recording device. [Means for Solving the Problems] Therefore, the present invention arranges a heating element in a nozzle,
When the heating element is driven, ink is discharged from the nozzle.
Inkjet recording apparatus using a recording head that ejects ink
The recording head based on the input image signal.
Head driving means for driving a heating element of the
Driving power supply means for supplying driving power;
Control means for controlling the driving of the recording head by moving means.
Control signal and power from the driving power supply means to the heating element.
Control to output power control signal to control power supply
Means, and the power control signal output from the control means.
Accordingly, supply of electric power from the driving power supply to the heating element is performed.
Supply control means for controlling supply, and malfunction of the control means.
Detection and malfunction of the control means is detected.
Runaway detection that causes the control means to reset the operation
Means, and wherein the control means
When the ink is ejected, the supply control means
Power from the driving power supply means to the heating element.
After outputting a power control signal for causing
Moving means for driving the heating element of the recording head
And output a control signal for
When the operation of the control means is reset, the control means
Driving the power control signal by the supply control means;
Signals that do not supply power from power supply means
It is a feature. [Operation] That is, according to the present invention, recording is performed by the control means.
Signal for controlling the driving of the pad, and the driving power supply
To control the power supply to the printhead heating element from the
Power control signal is output to drive and drive the printhead.
The supply of dynamic power is controlled. The control means discharges ink from the recording head.
The drive power supply to the printhead heating element.
After outputting a power control signal to supply power,
The heating element of the recording head is driven by the head driving means
Ejecting ink to output a control signal for
When discharging, start discharging after supplying power.
The output of the signal is controlled, and stable power is
To the heating elements. Furthermore, runaway of the control means is detected by the runaway detection means.
When the operation of the control means is reset by
Is a power control signal that controls the supply of power from the drive power supply
Is a signal that does not supply power,
Power is incorrectly supplied to the printhead heating element after
Inconvenience such as disconnection of the heating element can be prevented beforehand
You. Examples Hereinafter, the present invention will be described in detail with reference to the drawings. (External outline) Fig. 1 is a digital color copy to which the present invention can be applied.
1 shows an outline drawing of the machine. The whole can be divided into two parts. The first upper part reads the original image and reads the digital color image.
Color image scanner unit 1 that outputs image data
(Hereinafter abbreviated as scanner unit 1) and built into scanner unit 1.
Performs various image processing of digital color image data.
In addition to processing such as interface with external devices
And a controller unit 2 having a function. The scanner unit 1 is placed downward under the document holder 11
In addition to reading information from three-dimensional objects such as books and sheet manuscripts,
It also has a built-in mechanism for reading medium-size sheet documents.
I have. The operation unit 10 is connected to the controller unit 2.
It is used to input various information as a copier.
is there. The controller unit 2 performs scanning according to the input information.
An operation instruction is issued to the canner unit 1 and the printer unit 3.
If you need to perform complicated editing,
Attach input means such as a digitizer in place of manuscript holder 11,
By connecting this to the controller unit 2, advanced editing
It is also possible to perform collection processing. The lower part of FIG.
For recording digital image signals on recording paper
Counter 3. In this embodiment, the printer unit 3
A recording head having an electrothermal converter in the ejection energy generating element
Using a bubble jet recording head
It is a full-color inkjet printer. The two parts described above are separable and the connection cable
Can be installed in remote locations by extending
Of course it is possible. (Printer) FIG. 2 is a diagram showing the internal structure of the digital color copying machine shown in FIG.
It is sectional drawing which shows an example. Exposure lamp 14, lens 15, full color line image
Image sensor 16 capable of reading an image (this embodiment
Then, the original placed on the platen glass 17 by CCD)
Manuscript image, projected image by projector or sheet feed mechanism
The sheet original image by 12 is read. And various
Image processing is performed by the scanner unit 1 and the controller unit 2.
The recording is performed on the recording medium by the printer unit 3. In FIG. 2, recording media such as paper, film, etc.
The recording paper is a small fixed size (A4-A3 size in this embodiment).
Paper) (hereinafter referred to as cut paper)
Paper cassette 20 or large size (book
Row for recording A2 to A1 size in the embodiment)
Supplied from paper 29. Also, the recording medium is supplied one by one from the manual feed slot 22 in FIG.
By inserting it along the paper cover 21, it is possible to
Paper feeding, that is, manual paper feeding is also possible. Pick-up roller 24 is fed from paper cassette 20
Roller for feeding paper sheets one by one.
The cut paper is fed by the cut paper feed roller
Roller 26. The roll paper 29 is sent out by the roll paper feed roller 30.
Is cut to the standard length by the cutter 31,
It is carried out to LA26. Similarly, the recording paper input from the manual feed slot 22
The sheet is conveyed to the first sheet feeding roller 26 by the roller 32. Pick-up roller 24, cut paper feed roller 25, b
Paper feed roller 30, first paper feed roller 26 and manual feed roller
The roller 32 is provided with a sheet feeding motor (not shown) (for example, a DC servo motor).
Can be used) and is attached to each roller
ON / OFF control can be performed at any time by using the electromagnetic clutch
It has become. The print operation is started by the instruction from the controller unit 2.
When it is started, it is selected from one of the above
The conveyed recording paper is transported to the first paper feed roller 26. And the note
Make a predetermined amount of paper loop to remove the skew of the recording paper.
And then turn on the first paper feed roller 26 to feed the second paper feed roller 27
Convey the recording paper. Between the first paper feed roller 26 and the second paper feed roller 27,
Precise paper feed movement between the feed roller 28 and the second paper feed roller 27
In order to perform the operation, a certain amount of slack
to make. The buffer amount detection sensor 33 detects the buffer amount.
It is a sensor for detecting. Paper like this buffer
Especially when transporting large format recording paper
The paper feed roller 28 and the paper feed second roller 27 when feeding
Load can be reduced, and accurate paper feeding operation is possible.
become. When printing with the recording head 37, the recording head 37
The scanning carriage 34 composed of
The scanning motor 35 performs reciprocating scanning on the table 36. Outbound
Scans the image on the recording paper and scans the return path
Operates to feed the recording paper by the specified amount by the paper feed roller 28.
Do. At this time, the drive system is backed up by the paper feed motor.
A predetermined buffer while detecting with the
The control is performed so as to obtain the fa amount. The printed recording paper is discharged to the paper discharge
Complete the lint operation. Next, the details around the scanning carriage 34 will be described with reference to FIG.
A detailed explanation is given. In FIG. 3, the paper feed motor 40 intermittently feeds the recording paper.
The paper feed roller 28 and the paper feed
The two rollers 27 are driven. The scanning motor 35 moves the scanning carriage 34 to the scanning belt 34.
Drive source for scanning in the directions of arrows A and B
You. In this embodiment, the paper feed is controlled in order to make the paper feed control accurate.
Use a pulse motor for the motor 40 and the scanning motor 35.
ing. When the recording paper reaches the second paper feed roller 27, the paper feed mode
Turn on the printer 40 and feed the recording paper to the platen 39 to the paper feed roller 28.
Transport on top. The recording paper is detected by a paper detection sensor 44 provided on the platen.
The sense information is used for position control, jam control, etc.
Used. When the recording paper reaches the paper feed roller 28, the second paper feed row
Turn off the clutch 43 and the paper feed motor 40 and set the platen 39
Suction operation is performed from the inside of the unit by a suction motor (not shown)
The recording paper is brought into close contact with the platen 39. Prior to the image recording operation on the recording paper, the home position
The scanning carriage 34 is moved to the position of the
Next, a forward scan is performed in the direction of arrow A, and
Cyan (C), magenta (M), yellow (Y), bra
(BK) ink is provided for each color.
The recording is performed by discharging the recording head 37. Predetermined length
When the image recording for the minute is completed, the scanning carriage 34 is stopped, and
Then, the homeward scanning is started in the direction of arrow B and the home position is started.
The scanning carriage 34 is returned to the position of the scanning sensor 41. Return trip
During scanning, paper feed for the length recorded by the recording head 37
By driving the paper feed roller 28 by the feed motor 40,
In the direction of arrow C. In this embodiment, the recording head 37 is of a bubble jet type.
Inkjet nozzles, each with 256 nozzles
Are arranged in the recording paper conveyance direction orthogonal to the A and B directions.
Are used corresponding to the above four colors. The scanning carriage 34 is a home position sensor 41
Stops at the home position detected by
The recovery operation of the node 37 is performed. This ensures stable recording operation
This is a process for performing
At the start of ejection caused by changes in the viscosity of retained ink, etc.
To prevent unevenness, feed time, internal temperature, and discharge time
Depending on pre-programmed conditions, such as interzone,
(Not shown) placed near the home position
Move the device to engage the recording head 37, and in this state
Performs pressurizing operation to the recording head 37, idle discharge operation of ink, etc.
This is processing. By repeating the above operation,
Image recording is performed. (Scanner Unit) Next, the scanner unit 1 will be described with reference to FIGS.
Give an explanation. FIG. 4 illustrates an example of a mechanical configuration inside the scanner unit 1.
FIG. The CCD unit 18 includes a CCD 16, a lens 15, and the like.
A main scanning motor that is a unit and fixed on rails 54
50, pulley 51, pulley 52, wire 53
The drive system moves on the rails 54, and the main image
The reading in the scanning direction is performed. Shade 55, Home Positive
The sensor 56 is used for main scanning in the correction area 68 in the figure.
Position when moving the CCD unit 18 to the home position
Used for control. Rail 54 is mounted on rails 65 and 69 and
Motor 60, pulleys 67, 78, 71 and 76, shafts 72 and 73,
Is moved by the drive system in the sub-scanning direction
It is. Shade 57, home position sensors 58 and 59
Is a block for reading an original such as a book placed on the platen glass 17.
In sheet mode, the sheet mode for reading sheets
Rail at home position for each sub-scan when scanning
Used for position control when moving 54. Sheet feed motor 61, sheet feed rollers 74 and 75,
Wires 62 and 64, and wire 63
Mechanism. This mechanism is located on the platen glass 17 and faces downward.
The sheet original placed on the sheet feed rollers 74 and 75
Is a mechanism for feeding a predetermined amount at a time. Fig. 5 shows reading in book mode and sheet mode.
It is explanatory drawing of a picking operation. At the time of book mode, FIG.
Book mode home position shown in
Move the CCD unit 18 to the lock mode HP) and from here
Start reading the entire surface of the original placed on the platen glass 17.
Start. Prior to scanning the document, the correction area 68
Processing such as color correction, black level correction, and color correction. So
After that, main scanning is performed by the main scanning motor 50 in the direction of the arrow shown in the figure.
Start scanning in the direction. Reading operation of the area indicated by
When the operation is completed, the main scanning motor 50 is reversed,
Driving the sub-scanning motor 60 to the correction area 68
Move in the sub-scanning direction. Next, the main run of the area
Jedging correction and black level
Perform processing such as correction and color correction, and read the area of
Perform the operation. By repeating the above scanning,
Perform the reading operation and finish the reading operation of the area.
After that, the CCD unit 18 is again set to Book Mode Home
・ Return to position. In this embodiment, the platen glass 17 has a maximum A2 size.
In order to be able to read the original
Many scans must be performed, but in this description
The operation is simplified for easy understanding. In sheet mode, the CCD unit 18 is
Mode home position (seat mode HP)
Move to the area of the sheet original and feed the sheet feed motor
Scanning repeatedly while intermittently operating 61
Read the entire surface. Prior to scanning the document, the correction area 68
Processing such as color correction, black level correction, and color correction.
Then, in the direction of the arrow shown in the figure, the main scanning motor 50
Start scanning in the direction. Reading operation of the outbound path in the area
Is completed, the main scanning motor 50 is rotated in the reverse direction,
The sheet feed motor 61 is driven during the
It moves in the sub-scanning direction by an amount. Continue to do the same
The entire sheet document is read repeatedly. The reading operation described above is the same-size reading operation.
If so, the area that can be read by the CCD unit 18 is
As shown in FIG. 5, it is actually a large area. This is a book
The digital color copier according to the embodiment is enlarged or reduced.
This is because it has a built-in doubling function. That is, the above description
The area that can be recorded by the recording head 37 as shown in
For example, 50% reduction operation is performed
If this is not the case, at least double the 512-bit area image information is required.
It is important. Therefore, the scanner unit 1
Reads image information in any image area by main scanning
Output function is added. (Explanation of Entire Functional Blocks) Next, referring to FIG.
The functional blocks of the copying machine will be described. The control units 102, 111, and 121 respectively include the scanner unit 1,
A system for controlling the controller unit 2 and the printer unit 3
The control circuit is a microcomputer-type CPU,
ROM for storing RAM and fixed data, RA for storing data
M, a communication circuit and the like. Control between the control units 102-111
The units 111 and 121 are connected by a communication line,
The control units 102 and 121 operate according to the instruction of 111, so-called,
A master / slave control mode is adopted. The control unit 111 operates when operating as a color copier.
Operates according to the input instructions from the operation unit 10 and the digitizer 114.
Do. The operation unit 10 has, for example, a liquid crystal display unit as a display unit.
And a touch panel made of transparent electrodes on the surface.
By specifying, specify color and edit operation
Etc. can be input. Also works
Related keys, for example, start to instruct the start of copying operation
.Keys, stop keys that instruct copying operation to stop, and operations
Reset key and project to return the mode to the standard state
Use keys such as projector keys to select
The high key can be provided independently. Digitizer 114, as described with respect to FIG.
Enter location information for trimming, masking, etc.
For complicated editing processes
Connected as In addition, the control unit 111 is, for example, IEEE488, a so-called GP-IB
General-purpose parallel interface such as interface
It also controls the control circuit (I / F control unit) 112 and displays images between external devices.
Data input / output and mote control by external devices
This can be done through the interface. In addition,
The control unit 111 performs a multi-value synthesis that performs various processes related to the image.
Unit 106, image processing unit 107, binarization processing unit 108, binary synthesizing unit 109,
It also controls the buffer memory 110. The control unit 102 controls the driving of the mechanism of the scanner unit 1 described above.
Control of the mechanism drive unit 105 for controlling
Exposure control unit 103, which controls the exposure of the lamps
Controls the exposure of the halogen lamp 90 when the
The exposure controller 104 is controlled. Further, the control unit 102
Analog signal processing unit 10 that performs various processes related to images
0, the input image processing unit 101 is also controlled. The control unit 121 controls the driving of the mechanism of the printer unit 3 described above.
Mechanism driving unit 122 for controlling the operation of the printer unit 3
Of time variation and recording heads 37C, 37M, 37Y and 37B
Synchronous delay memo for delay correction by arrangement on K mechanism
The control of the key 115 is performed. Next, the image processing block shown in FIG.
Will be explained. The image formed on the CCD16 is converted by the CCD16 into an analog
It is converted into an air signal. The converted image information is red → green →
Analog signal processing unit 10 processed serially like blue
Entered as 0. In the analog signal processing unit 100, each color of red, green, and blue is
Sample & Hold, Dark Level Correction, Dynami
Analog / digital conversion after controlling the
Conversion (A / D conversion) and serial multi-value (in this embodiment, each color
(8-bit length) digital image signal
Output to the processing unit 101. In the input image processing unit 101, shading correction and color
Correction processing necessary for the reading system such as positive and
This is performed as it is with a real multi-valued digital image signal. The multi-value synthesizing unit 106 of the controller unit 2 includes the scanner unit 1
And the serial multi-level digital image signal
Serial multi-valued digital sent via real I / F
Circuit block for selecting and synthesizing image signals
It is. Selectively synthesized image data is a serial multi-valued
The digital image signal is sent to the image processing unit 107 as it is. The image processing unit 107 performs smoothing processing, edge enhancement,
Black extraction, of recording ink used in the recording head 37C-37BK
This is a circuit for performing a masking process or the like for color correction.
Serial multi-level digital image signal output
108 and the buffer memory 110, respectively. The binarization processing unit 108 performs serial multi-valued digital image signal
This is a circuit for binarizing a signal.
Simple binary processing by using the
You can choose. Where the serial multi-valued digital
The image signal is converted into a four-color binary parallel image signal.
4 colors for the binary synthesis unit 109, 3 colors for the buffer memory 110
Is sent. The binary synthesizing unit 109 is sent from the buffer memory 110
Coming binary color image signals of three colors and the binarization processing unit 108
4 color parallel image signal that is sent
A circuit for synthesizing a binary parallel image signal of four colors
It is. The buffer memory 110 is a multi-valued image via a parallel I / F.
Buffer memory for input and output of images and binary images
Yes, it has memory for three colors. The synchronization delay memory 115 of the printer unit 3
Absorption of time variance of mechanical operation and recording head 37C-37B
A circuit for delay correction by the arrangement of K
Yes, internally, the data required to drive the printheads 37C-37BK
It also generates the imming. Head driver 116 drives recording head 37C-37BK
An analog drive circuit for performing the recording head 37C-3
A signal that can directly drive 7BK is generated internally. The recording heads 37C, 37M, 37Y and 37BK are
Ejects inks of magenta, magenta, yellow and black
Then, the image is recorded on the recording paper. FIG. 7 shows an image between blocks of the circuit described in FIG.
FIG. 4 is an explanatory diagram of output timing. The signal BVE is used for the main scanning reading operation described with reference to FIG.
This signal indicates an image effective section for each scan. Signal BV
By outputting E multiple times, full-screen image output is performed.
Be done. The signal VE contains the image of each line read by the CCD16.
This is a signal indicating the effective section. When signal BVE is enabled, signal VE
Only becomes effective. The signal VCK is a sending clock signal of the image data VD.
is there. The signals BVE and VE are also synchronized with this signal VCK.
Change. The signal HS is discontinuous while the signal VE outputs one line.
This signal is used to repeat the effective and invalid sections.
If the signal VE is valid continuously for one line output,
This is an unnecessary signal. Indicates the start of one line image output
Signal. Next, the present invention will be described in detail with reference to FIG. 8th
The figure shows blocks showing details of the control system around the printhead 37.
FIG. 10 shows parts that can be configured in the same manner as the conventional example of FIG.
Therefore, the same reference numerals are given and the description is omitted. In FIG. 8, 257 supplies electric power to the head heater 204.
In this embodiment, the head drive power supply is a voltage of 26V.
It is a DC power supply in the form of an switching regulator. Also power
The 257 has a remote terminal.
When R is shorted to GND, a DC output of 26V is obtained,
When the child R is open, an output of 26 V cannot be obtained. In addition, a printer in the printer control unit 121 of the printer unit 3
The sequence controller 251 of the
Output the signal Pon. This signal Pon drives the head
This is a control signal for the power supply.
It is connected to the register 225. Now sequence control
When the roller 201 attempts to eject ink from the head,
First, the signal Pon is set to low level, and
Turn on the transistor 225 and connect the remote terminal R of the power supply 217
Short to GND. After that, AND gate 2
The gate 21 is opened to start discharging. Also vomit
When the output is completed, set the signal Pon to high level and
225 is turned off and the remote terminal R of the power supply 257 is opened.
To stop the power supply. Here, the logic part malfunctions due to disturbance noise.
To protect the head heater 204.
The Troller 251 has a signal Pon and a signal HENB at certain intervals.
Reset the signal Pon and signal ENB while monitoring. Also
When the sequence controller 251 runs away due to disturbance
Is reset by the runaway detection circuit 220,
At this time, even if reset is performed to deal with runaway
To prevent the inconvenience that 7 outputs 26V, the signal Pon
Active low. In the above embodiment, the bubble jet method is used.
Full-color inkjet recording device using a recording head
-The case of application to copying machines was described,
The present invention can be applied regardless of the type and amount of
Of course. For example, the recording head uses a piezo element
May be used, full color printer, single color
The present invention can be applied to a copying machine, a monochrome printer, and the like. Ma
In the case of the above-described embodiment, the recording operation is performed only on the outward path.
However, there is no problem even when performing round-trip recording.
No. Further, in the above example, the recording head is shifted in the width direction of the recording paper.
Although the printer that performs recording by moving it has been described,
Nozzles arranged in the main scanning direction over the entire width of the recording paper
A so-called full multi-type printer may be used. [Effects of the Invention] As described above, according to the present invention, the control means
Control signals for controlling the driving of the recording head, and
Power from the drive power supply to the heating element of the printhead.
Output a power control signal for controlling the printhead.
The operation and the supply of driving power are controlled. The control means discharges ink from the recording head.
The drive power supply to the printhead heating element.
After outputting a power control signal to supply power,
The heating element of the recording head is driven by the head driving means
Ejecting ink to output a control signal for
When discharging, start discharging after supplying power.
The output of the signal is controlled, and stable power is
To the heating elements. Furthermore, runaway of the control means is detected by the runaway detection means.
When the operation of the control means is reset by
Is a power control signal that controls the supply of power from the drive power supply
Signal by which power is not supplied,
Power is accidentally supplied to the heating element of the print head after setting.
Inconvenience such as disconnection of the heating element
Wear. In addition, the circuit configuration described above reduces the number of components to existing circuits.
Has the advantage that it can be easily realized only by adding

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an external configuration example of a digital color copying machine as an example of a device to which the ink jet recording apparatus of the present invention can be applied, and FIG. 2 is a digital color printer shown in FIG. FIG. 3 is a cross-sectional view showing an example of the internal configuration of the copier; FIG. 3 is an explanatory diagram showing a detailed configuration example around the scanning carriage 34 of the printer unit; FIG. 4 is an explanatory diagram for explaining an internal configuration example of the scanner unit; FIG. 5 is an explanatory diagram for explaining a reading operation by a scanner unit in a book mode and a sheet mode, and FIG. 6 is a block diagram showing an example of an electric configuration of a digital color copying machine to which the present invention is applied. 7 is a timing chart for explaining the operation, FIG. 8 is a block diagram showing an example of a configuration of a control system around the print head according to the embodiment, and FIG. 9 is a conventional control system around the print head. Block diagram of the system, Fig. 10 at power-on, is a timing chart showing the deposition of each section signal during cutoff. DESCRIPTION OF SYMBOLS 1 ... Scanner part, 2 ... Controller part, 3 ... Printer part, 10 ... Operation part, 34 ... Carriage, 35 ... Scan motor, 37 ... Recording head, 111, 121 ... Control part, 115 ...... Synchronous delay memory, 201 ... sequence controller, 202 ... head driver circuit (head driving means), 203 ... recording head, 204 ... head heater (heating element), 205 ... temperature sensors, 216, 217 ... ... power supply, 220 ... runaway detection circuit (runaway detection means), 224 ... inverter, 225 ... transistor (supply control means), 251 ... sequence controller (control means), 257 ... power supply (drive power supply means), VD: Image signal, HENB: Control signal, Pon: Power control signal.

Claims (1)

(57) [Claims] In an ink jet recording apparatus using a recording head that disposes a heating element in a nozzle and discharges ink from the nozzle by driving the heating element, the heating element of the recording head is controlled based on an input image signal. A head driving unit for driving; a driving power supply unit for supplying electric power for driving the heating element; a control signal for controlling driving of the recording head by the head driving unit; and a driving signal from the driving power supply unit to the heating element. Control means for outputting a power control signal for controlling the supply of power, and according to the power control signal output from the control means,
Supply control means for controlling the supply of power from the driving power supply means to the heating element; detecting malfunction of the control means, and resetting the control means when detecting malfunction of the control means. Control means for causing the supply control means to supply power from the driving power supply means to the heating element when causing the recording head to eject ink. After outputting the power control signal, the head drive means outputs a control signal for driving the heating element of the recording head, and when the operation of the control means is reset by the runaway detection means, Means for causing the power control signal to be a signal for preventing power from being supplied from the drive power supply means by the supply control means. Recording device.