JP2001080060A - Recording head, head cartridge with the recording head, recording apparatus using the recording head, and, recording head element substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording head and a recording apparatus using the recording head for outputting as digital data outputs from a sensor element set to monitor various states of the recording head. SOLUTION: An output from an element for detecting a state of the recording head, e.g. information representing a temperature of a substrate 101, a resistance value of an electrothermal conversion body, an ON resistance of a power transistor for driving the electrothermal conversion body, etc., is all digitized by an A/D converting block 130 on the substrate. The information is outputted outside as digital information afterwards. At this time, the number of wirings and an area of the substrate are prevented from being increased by utilizing a clock signal and a latch signal used for transferring recording data to the recording head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a recording head, a head cartridge having the recording head, a recording apparatus using the recording head, and a recording head substrate, and more particularly to a recording head and a recording apparatus using the recording head. And transmission and reception of data with the

[0002]

2. Description of the Related Art An electrothermal transducer (heater) of a recording head mounted on a recording apparatus according to a conventional ink jet system.
And a driving circuit for driving it according to the input image signal,
For example, as shown in JP-A-5-185594, they are formed on the same substrate by using a semiconductor process technique. Further, it has been proposed to form an element on the same substrate for detecting a state on the substrate, for example, a distribution state of the substrate temperature and the resistance value, a variation in characteristics of the driving circuit, and the like.

FIG. 8 is a block diagram conceptually showing a method of detecting a substrate state in a conventional ink jet recording head.

In FIG. 8, reference numeral 101 denotes a semiconductor substrate (hereinafter, referred to as a substrate) constituting a recording head, and reference numeral 102 denotes an array of a plurality of electrothermal transducers (heaters) for generating heat energy necessary for discharging ink. Heater array, 1
03 denotes one heater constituting the heater array 102, 1
Reference numeral 04 denotes a power transistor block that supplies a desired current to the heater to drive the heater, and reference numeral 105 denotes a logic including a latch circuit and a shift register for switching ON / OFF of each heater in accordance with external data transfer. A circuit section, 106 is a power supply line for applying a predetermined voltage to the heater to supply a current, 107 is a GND line into which the current flowing through the heater and the power transistor flows, and 108 and 109 are a GND line and a power supply line, respectively. A GND terminal and a power supply terminal for pulling out to the outside of the head.

[0005] Further, reference numeral 410 denotes a temperature detecting element for detecting the temperature of the substrate 101, and 411 denotes a temperature detecting element 410.
412, a terminal for extracting the signal of the temperature detecting element to the outside of the recording head, 420, a resistor for monitoring the resistance value of the electrothermal transducer formed on the substrate, 421 Is a wiring for applying a voltage to the resistor 420 to measure the resistance value, 422 is a terminal for drawing out the wiring 421 to the outside of the recording head, and 430 processes the output of the temperature detecting element and the resistance monitoring resistor. Signal processing circuit blocks 413 and 423 are wires for connecting the temperature detection element 410, the resistor 420 and the signal processing circuit block 430, respectively, and 440 is a signal processing circuit block 4
The decision circuit block 450 receives the output from the circuit 30, detects the state of the board, and feeds back appropriate control to the board according to the state. 450 is a signal processing circuit block 430.
And 460, a wiring connecting the determination circuit block 440 and the logic circuit unit 105 in the substrate.

Here, the concept of substrate temperature detection and control in accordance with the detected temperature in a conventional recording head will be described with reference to FIG.

The heater array 102 is supplied with a current for generating thermal energy required for ejection by a power transistor, and the timing at which the current is passed is determined by a driving method which is optimal for recording information and a substrate state corresponding to the time. Are determined by the determination circuit block 440, a control signal according to the determined driving method is sent to the logic circuit unit 105, and the logic circuit unit 105 supplies the control signal to the control terminal of the power transistor.

At this time, the amount of heat generated by the heater and the heat generation time are determined by the timing of the current flowing through the heater, and the ink corresponding to the amount is discharged. However, the heat generated by the heater is not only supplied to the ink but also to the substrate 101, so that the temperature of the substrate 101 rises at the same time. Therefore, ink cannot always be ejected under certain conditions. That is,
It is difficult to maintain the same ejection state over a wide temperature range only with a fixed drive timing. For this reason, it is necessary to drive the heater while selecting the optimum conditions for ink ejection while detecting the substrate temperature.

Therefore, it is desirable that an element capable of monitoring a temperature change in the substrate, that is, an element having a known temperature characteristic. For example, a pn junction diode is used, and the forward voltage-current characteristic of the diode is used. Used. This diode is placed on the substrate, and the characteristic change of this element is detected from the outside at regular intervals, and the temperature change of the substrate during that period is detected based on the value. By supplying the timing from the outside, stable ink ejection can be maintained over a wide temperature range.

That is, in the circuit shown in FIG. 8, a predetermined voltage is applied to the power supply terminal 109, and a timing pulse based on recording information and driving conditions is input from the logic circuit unit 105 to the power transistor block 104. And the corresponding heater 10 in the heater array 102
3 is driven, and ink is ejected from a nozzle at a specific position corresponding to the driving heater.

At this time, if the heating operation to the heater is continuously repeated, the temperature of the substrate rises accordingly. However, the temperature detecting element 410 outputs an output signal corresponding to the substrate temperature to the wiring 411 in the substrate and the terminal. 412, wiring 4 outside the substrate
13 to the signal processing circuit block 430 on the device side. Normally, the output of the temperature detection element 410 is an analog output, and the signal processing circuit block 430 amplifies the analog output, converts it to a digital value, and sends the digital value to the determination circuit block 440 via the wiring 450. .

The determination circuit block 440 detects a rise in the temperature of the substrate 101 based on the digital value, and sends a drive signal indicating an optimum drive condition at that temperature to the logic circuit unit 105 via the wiring 460. Accordingly, the logic circuit unit 105 supplies a timing pulse corresponding to the substrate temperature to the power transistor, and as a result, the heater is driven to discharge ink.

As described above, by detecting the temperature of the substrate every certain period, even if the temperature of the substrate changes,
It is possible to always maintain stable ejection conditions.

Next, the concept of monitoring the resistance value of an electrothermal transducer (heater) formed on a substrate in a conventional recording head and the control according to the monitoring result will be described.

In the ink jet recording head, the heat generated by the heater 103 causes the ink to boil, and the ink is ejected by the pressure of the bubbles generated thereby to perform the recording. Q = I ² using the current (I) flowing through the heater and the resistance (R) of the heater.
It is represented by R. According to the relationship between Q and R, the amount of heat (Q) generated by the resistance value (R) of the heater itself changes. Therefore, the formation of bubbles due to this will also change.

Considering the case where the recording head is newly replaced, the amount of heat (Q) generated by this replacement depends on the resistance value of the heater of the new recording head. However, since there is an individual difference (variation) in the heater resistance value, if the heater is always driven under the same driving condition, the amount of generated heat is different, and as a result, uniform printing cannot be performed. In general, when a thin film resistor of a metal or a metal compound formed by a semiconductor process is used to form a heater, the manufacturing variation is ± 20%.
Expected to be about.

For this reason, by detecting the heater resistance value of each recording head and supplying an optimum drive timing corresponding to the detected resistance value from the outside, stable ink ejection can be performed even when the resistance value varies. It is necessary to keep.

That is, in the circuit shown in FIG. 8, the element of the resistor 420 used for monitoring the heater resistance value is formed of the same material and the same process as the heater 103 that actually generates heat. The value is set to the wiring 421 in the board,
The signal is read by the signal processing circuit block 430 via the terminal 422 and the external wiring 423.

The output from the resistance value 420 to the outside of the recording head is an analog output. The signal processing circuit block 430 amplifies the analog output and converts it to a digital value, and then routes the digital value to the determination circuit block 440. 4
Send via 50. The determination circuit block 440 detects the heater resistance value based on the digital value, and feeds back a drive signal indicating an optimum drive condition according to the resistance value to the logic circuit unit 105 via the wiring 460.

By performing such control when a new recording head is replaced or when the power of the printer body is turned on, stable ink ejection conditions can be maintained at all times even with heaters having different resistance values. ing.

In addition to the above-described substrate temperature of the recording head, ID (identification) information of the recording head for changing the drive control, rank information for determining the recording parameters, and the like are transmitted from the recording head. It has also been proposed to transmit to the device body.

[0022]

However, in the above conventional example, the output of the information indicating the detected substrate temperature and the information indicating the monitored heater resistance value are both output from the substrate to the outside of the recording head as analog outputs. It is performed for. For this reason, for example, the effects of power supply noise and GND noise generated when a large current flows in synchronization with a heat pulse for ink ejection, and the effects of coupling noise and radiation noise jumping into a wiring drawn outside are described above. There is a problem that each piece of information is easily received and it is difficult to read the information with high accuracy.

The use of a noise elimination circuit, element, or the like to reduce the above-mentioned noise increases the number of components constituting the recording head and the space for the substrate, resulting in an increase in cost. Furthermore, in order to use the analog output as it is for signal control, be sure to use an A / D converter.
Since it is necessary to convert the data once to a digital value and send it to the judgment circuit, an A / D converter must be provided outside the recording head, which complicates the configuration of the entire system and increases the cost. Had become.

The present invention has been made in view of the above conventional example, and improves the noise resistance of an output from a sensor element provided for monitoring various states of a recording head to obtain a more accurate sensor output. By reducing the number of circuits and elements for noise removal,
It is a first object of the present invention to provide a recording head that reduces costs and a recording apparatus that uses the recording head.

Further, transmission and reception of signals between the printhead and the printing apparatus main body are usually performed using an input / output pad (PAD). In addition to the above temperature information, printhead identification information and rank information are transmitted and received. For this reason, the number of pads increases, so that the following disadvantages are caused.

(1) If the number of pads is large, the area of the circuit board of the recording head becomes large, which leads to an increase in the size of the apparatus and an increase in cost.

(2) Since the number of pointing wires for connecting the pads to the external contacts increases, the number of steps in manufacturing the recording head increases, which leads to an increase in cost.

(3) Increasing the number of control signal lines hinders cost reduction due to simplification of the circuit board.

The present invention has been developed in order to solve such disadvantages.
It is a second object of the present invention to provide a recording head capable of reducing the size of the apparatus by reducing the number of pads on the circuit board of the recording head and suppressing the production cost, and a recording apparatus using the recording head.

In particular, when transmitting the identification information and rank information of the recording head to the apparatus main body side, in proportion to the information amount,
The number of wirings from the recording head to the main board of the apparatus main body increases, which leads to an increase in the area of the contact portion (pad) and both substrates, and also causes an increase in cost.

Also, information that fluctuates with time, such as temperature information, needs to be transmitted periodically even during the recording operation. Therefore, the information is usually transmitted using a unique transfer clock different from the clock for recording data. , And the number of wires for the transfer clock further increases. At this time, since the transfer clock signal becomes a noise source together with the recording data clock, it is necessary to consider a wiring path, and a special circuit or component is required to reduce the influence of the generated noise. There is.

According to the present invention, the production cost can be reduced by preventing the increase in the number of wirings and the area of the substrate and the generation of noise even when the amount of information transmitted from the recording head to the apparatus main body increases. A third object is to provide a recording head that can be suppressed and a recording apparatus that uses the recording head.
The purpose is.

Further, the temperature of the recording head is generally detected by using a comparator. However, it takes time to switch the reference voltage and to operate the comparator. When the data transfer speed is increased, there is a disadvantage that the transfer of the temperature data cannot be performed in time.

In particular, if the transfer speed of print data from the printing apparatus is matched with the transfer speed of temperature data, it is not possible to cope with recent demands for higher print speeds. Also,
Although it is possible to speed up the switching of the reference voltage and the operation of the comparator, the current consumption of the analog circuit for executing these operations is increased by that much, and the recording operation is waiting (that is, the temperature is detected). Another problem arises in that the power consumption in the non-operating state) is greater than that of a digital circuit for receiving and storing print data.

To cope with this problem, it is conceivable to control the power supply of the analog circuit from outside the recording head. However, a voltage drop in the control circuit for turning on / off the power supply affects the temperature detection accuracy. Also, there are many problems such as an increase in the number of signal lines connecting the recording head to the outside.

The present invention solves such a problem.
It is a fourth object of the present invention to provide a recording head capable of detecting and transmitting temperature information while supporting high-speed transfer of recording data, and a recording apparatus using the recording head.

[0037]

According to a first aspect of the present invention, there is provided a recording head for achieving the first object, comprising: an electrothermal transducer for generating thermal energy used for discharging ink; A recording head in which a drive circuit for driving the electrothermal transducer is provided on the same element substrate, a sensor that detects a state of the element substrate and performs analog output, and an analog output of the sensor. An A / D converter for converting into a digital value, wherein the sensor and the A
A / D converter is provided on the element base.

The driving circuit includes a power transistor for driving the electrothermal transducer, a shift register for temporarily storing recording data for driving the power transistor, and a recording register for storing the data stored in the shift register. And a latch circuit for latching data.

The state of the element substrate includes a temperature of the element substrate, a resistance value of the electrothermal converter, an ON resistance value of the power transistor, and the like.

The sensor is a pn junction diode having a known temperature characteristic for detecting the temperature of the element substrate, and the same material as the electrothermal converter for detecting the resistance value of the electrothermal converter. In order to detect the resistance formed in the same process and the ON resistance of the power transistor, it is preferable that the power transistor be formed of a transistor having the same conductivity type as the power transistor and formed in the same process.

Further, digital information indicating the resistance value of the electrothermal converter, the ON resistance of the power transistor, and the like is stored. For example, an EPROM, an EEPROM, a fuse type R
It is desirable to provide a non-volatile memory such as OM which does not change with time on the substrate. The nonvolatile memory may store digital information indicating the resistance value of the electrothermal transducer and the ON resistance of the power transistor measured when the recording head is shipped from the factory.

With the above configuration, in the recording head according to the first aspect of the present invention, the output from the element for detecting the state of the recording head is digitized on the element substrate, and then the digital information is output to the outside. I do.

A first object of the present invention is to provide a recording apparatus for performing recording by using the recording head having the above-mentioned configuration, wherein the recording apparatus receives information output from the sensor and converted into a digital value, and converts the information into digital information. The present invention is also achieved by a printing apparatus having control means for controlling the drive of the printhead based on the control information.

Further, a recording head element substrate according to the present invention, which achieves the first object, comprises an electrothermal conversion element for generating thermal energy used for discharging ink, and a driving element for driving the electrothermal conversion element. A printhead element substrate provided on the same element substrate as a drive circuit for performing the operation, a sensor for detecting the state of the substrate and outputting an analog output, and an A for converting the analog output of the sensor to a digital value. / D converter, wherein the sensor and the A / D converter are provided on the substrate.

A recording head according to a second aspect of the present invention that achieves the second object is a recording head that performs recording by discharging ink in accordance with an ink-jet method, and includes recording of a plurality of recording elements that discharge ink. A memory that stores the characteristics, a conversion circuit that converts an analog signal into digital data and outputs the data, and a drive circuit that drives the plurality of printing elements in accordance with the input recording signals, Reading is performed using a clock signal and a latch signal used to input the recording signal, and further, a digital signal is output from the conversion circuit using the clock signal.

Each of the plurality of printing elements driven by the drive circuit includes a heater, a switch for controlling on / off of energization of the heater, and a discharge nozzle for discharging ink heated by heat generated from the heater. It is desirable to include

The drive circuit has a shift register and a latch circuit, and a first input pad for inputting a heat pulse signal to the heater and a second input pad for inputting a recording signal to the shift register. And a third input pad for inputting a clock signal, and a fourth input pad for inputting a latch signal to the latch circuit.

On the other hand, the memory includes a plurality of ROMs and a plurality of shift registers corresponding to each of the plurality of ROMs, and a plurality of shift registers are provided in accordance with a clock signal input from a third input pad. A read signal is output from the register to each of the plurality of ROMs, and the plurality of ROs are output.
It is preferable to output information stored in each of M serially.

Further, the conversion circuit receives read signals output from the plurality of shift registers and generates a threshold signal for performing analog / digital conversion. The conversion circuit may further include a reduction circuit for reducing the frequency of the read signals output from the plurality of shift registers, and may perform analog / digital conversion on an analog signal according to the frequency reduced by the reduction circuit. good.

The output from the temperature sensor for measuring the internal temperature of the recording head can be used as the analog signal.

A recording head according to a third aspect of the present invention for achieving the third object is a recording head for performing recording in accordance with an inputted recording signal, comprising: a non-volatile memory storing information relating to the recording head; Output means for outputting information stored in the memory to the outside in a serial format within a period in which the recording signal is input, using a clock signal and a latch signal used to input the recording signal; and It has.

Further, the recording head of the present invention converts information relating to the state of the recording head into digital data, and uses the converted digital data with a clock signal and a latch signal used for inputting the recording signal. The image processing apparatus may further include a conversion unit that outputs the data in a serial format to the outside during a period in which the recording signal is input.

The non-volatile memory stores identification information of the recording head, and preferably includes at least one of an EPROM, an EEPROM, and a fuse ROM.

Further, it is preferable that the output means is configured to output the information stored in the memory bit by bit in synchronization with the clock signal.

A recording head according to a fourth aspect of the present invention for achieving the fourth object is a recording head capable of outputting temperature information in accordance with input of recording data, and recording in accordance with a clock of a first frequency. A shift register for inputting data, a heater that is energized and generates heat according to the print data, a temperature detection circuit that detects a temperature inside the print head, and a second clock that divides the clock of the first frequency to generate a second clock.
A frequency dividing circuit that generates a clock having a frequency of
A signal indicating the detected temperature is output.

Here, the temperature detecting circuit includes a temperature sensor, a reference voltage generating circuit for generating a reference voltage, and the second
A switching circuit for changing the reference voltage in accordance with a clock having a frequency of, and comparing the output voltage from the temperature sensor with the reference voltage from the switching circuit, and outputting the comparison result as a signal indicating the detected temperature. It is desirable to have a circuit.

Further, it is preferable that the frequency dividing circuit is capable of dividing the clock of the first frequency by at least two.

Further, it is preferable to have a latch circuit for latching the recording data stored in the shift register.

When the recording head is an ink jet recording head which performs recording by discharging ink, the recording head uses thermal energy to discharge ink so that thermal energy given to ink is used. It is desirable to have a thermal energy converter for generating the heat energy.

[0060]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

The "recording" used in the present invention
The term means not only giving an image having a meaning such as a character or a figure to a recording medium, but also giving an image having no meaning such as a pattern.

The present invention also provides a facsimile or communication system having a printer, a copier, a communication system for recording on a recording medium such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, and the like. The present invention is applicable to a printer system in which a system and a printer unit are combined, a device such as a word processor having a printer unit, and an industrial recording device in combination with various processing devices.

Further, the term "element substrate" used below does not indicate a mere substrate made of a silicon semiconductor but a substrate provided with each element, wiring, and the like.

Further, the expression “on the element substrate” used in the following description indicates not only the upper side of the element substrate but also the surface of the element substrate and the inside of the element substrate near the surface. The term "built-in" as used in the present invention is not a term indicating that each element is simply disposed on a substrate, but is a step of manufacturing a semiconductor circuit. This indicates that the device is integrally formed and manufactured on an element substrate by, for example, the method described above.

First, a typical overall configuration and a control configuration of a recording apparatus using the recording head of the present invention described below will be described.

FIG. 1 is an external perspective view showing the outline of the configuration of an ink jet printer IJRA using the recording head of the present invention. In FIG. 1, a spiral groove 500 of a lead screw 5005 that rotates via driving force transmission gears 5009 to 5011 in conjunction with forward and reverse rotation of a drive motor 5013.
The carriage HC engaged with the carriage 4 has a pin (not shown), and is supported by the guide rail 5003 to reciprocate in the directions of arrows a and b. The print head I is provided on the carriage HC.
An integrated ink jet cartridge IJC containing a JH and an ink tank IT is mounted. A paper pressing plate 5002 presses the recording paper P against the platen 5000 in the moving direction of the carriage HC. 500
Reference numeral 7,5008 denotes a photo coupler, which is a lever 5 of the carriage.
006 is a home position detector for confirming the existence in this area and switching the rotation direction of the motor 5013. Reference numeral 5016 denotes a member for supporting a cap member 5022 for capping the front surface of the recording head IJH.
Reference numeral 5 denotes a suction device that suctions the inside of the cap, and performs suction recovery of the recording head through the opening 5023 in the cap. 50
Reference numeral 17 denotes a cleaning blade. Reference numeral 5019 denotes a member that allows the blade to move in the front-rear direction. These members are supported by a main body support plate 5018. It goes without saying that the blade is not limited to this form and a known cleaning blade can be applied to this example. Reference numeral 5021 denotes a lever for starting suction for recovery of suction. The lever 5021 moves with the movement of the cam 5020 that engages with the carriage, and the driving force from the driving motor is controlled by a known transmission mechanism such as clutch switching. Is done.

The capping, cleaning, and suction recovery are configured so that desired processing can be performed at the corresponding position by the action of the lead screw 5005 when the carriage comes to the area on the home position side. If a desired operation is performed at the timing, any of the embodiments can be applied.

Next, a control configuration for executing the recording control of the above-described apparatus will be described.

FIG. 2 is a block diagram showing a configuration of a control circuit of the ink jet printer IJRA. In the figure showing a control circuit, 1700 is an interface for inputting a recording signal, 1701 is an MPU, 1702 is an MPU 170
ROM for storing a control program to be executed by PC 1, 170
Reference numeral 3 denotes a DRAM for storing various data (such as the print signal and print data supplied to the print head IJH). Reference numeral 1704 denotes a gate array (GA) for controlling supply of print data to the print head IJH, and includes an interface 1700, an MPU 1701, and a RAM 1703.
It also controls data transfer between them. 1710 is a recording head IJ
Reference numeral 1709 denotes a carrier motor for transporting a recording medium such as recording paper. 170
5 is a head driver for driving the recording head, 1706
Reference numeral 1707 denotes a motor driver for driving the transport motor 1709 and the carrier motor 1710, respectively.

The operation of the above control configuration will be described. When a recording signal enters the interface 1700, the gate array 17
04 and the MPU 1701 converts the recording signal into recording data for printing. Then, the motor driver 17
06 and 1707 are driven, and the head driver 1
Print head IJH according to the print data sent to
Is driven, and recording is performed.

As described above, the ink tank IT and the recording head IJH may be integrally formed to constitute a replaceable ink cartridge IJC. However, the ink tank IT and the recording head IJH are separated. It may be configured so that only the ink tank IT can be replaced when the ink runs out.

FIG. 3 is an external perspective view showing the structure of an ink cartridge IJC in which the ink tank and the head can be separated. As shown in FIG. 3, the ink cartridge IJC holds the ink tank IT and the recording head I at the position of the boundary line K.
JH can be separated. When the ink cartridge IJC is mounted on the carriage HC, the ink cartridge IJC is provided with an electrode (not shown) for receiving an electric signal supplied from the carriage HC side. Is driven to eject ink.

In FIG. 3, reference numeral 500 denotes an ink ejection port array. The ink tank IT is provided with a fibrous or porous ink absorber for holding ink, and the ink is held by the ink absorber.

Hereinafter, transmission and reception of data between the recording head and the apparatus main body will be described in detail with reference to a specific embodiment of the recording head of the present invention.

<First Embodiment> FIG. 4 is a block diagram showing a circuit for controlling the driving of the recording head IJH according to the first embodiment of the present invention.

In FIG. 4, the same components as those shown in the conventional example of FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 4, reference numeral 120 denotes an element block having an element for detecting the state of the substrate 101 as a structure formed on a substrate (element base) 101 of the recording head, and 130 denotes an element block 120. An A / D conversion block 131 digitizes the output signals of the elements inside, and 131 is a terminal for drawing the output of the A / D conversion block 130 to the outside of the recording head IJH. A determination circuit block 140 receives the output of the A / D conversion block 130, detects the state of the substrate 101, and feeds back appropriate control according to the state to the substrate 101.
External wiring 160 connecting 1 to the determination circuit block 140;
Is a wiring connecting the determination circuit block 140 and the logic circuit unit 105.

Note that, with reference to FIG. 2, the determination circuit block 140 is the MPU 170 of the control circuit shown in FIG.
1 and a part of the function executed by the head driver 1705.

FIG. 5 is a view showing each element constituting the element block 120 formed on the element substrate.

As shown in FIG. 5, the element block 120
Is formed of the same material and in the same process as the pn junction diode 201 having a known temperature characteristic as a temperature detecting element for detecting the temperature and the heater 103 for monitoring the resistance value of the heater 103 for discharging ink. And a monitoring transistor 203 formed of the same conductivity type and the same process as the power transistor for monitoring the ON resistance of the power transistor. A constant current is supplied from the constant current source 210 to each of these elements, and an output voltage reflecting the substrate temperature, the heater resistance value, and the ON resistance of the power transistor is output from an output terminal 220 provided in each element. Output by value.

Here, a description has been given of a configuration having three elements, that is, a temperature detection element, a monitoring resistor, and a monitoring transistor, as elements constituting the element block 120. However, any one of these elements may be used alone. Or a combination thereof.

Each element constituting the element block 120, that is, the pn junction diode 201 and the resistor 20
2. When a constant current is supplied from the constant current source 210 to the transistor 203, the following output is obtained from the terminal 220.

When the pn junction diode 201 is used as an element, a forward voltage is output from the terminal 220 corresponding to the substrate temperature at that time. When the resistor 202 is used as an element, a heater for discharging is used. A potential drop corresponding to the resistance value corresponding to the resistance value of 103 is output from the terminal 220,
When the transistor 203 is used as an element, a potential drop corresponding to a resistance value corresponding to the ON resistance value of the power transistor is output from the terminal 220. Note that these output voltages are all analog values.

FIG. 6 is a block diagram for explaining the relationship with the A / D conversion block 130 for converting an analog output output from the element block 120 into a digital value.

In FIG. 6, reference numeral 301 denotes an A / D converter.

The output signal obtained from the terminal 220 shown in FIG. 5 is converted into a digital value by the A / D converter 301. At this time, the element block 120 shown in FIG.
The same effect can be obtained even if the constant current source 201 inside is an external current source, that is, a constant current source supplied from outside the print head IJH, and other means for obtaining the characteristics of each element, for example, The same effect can be obtained by replacing with a constant voltage source or a fixed pattern generator.

Further, the A / D converter 301 can select an arbitrary one in terms of its system and accuracy within a necessary range.

For example, an embodiment in which the forward voltage of a PN junction diode for detecting a rise in the temperature of a substrate is subjected to A / D conversion will be described below.

Here, since the A / D converter built on the substrate needs to be configured on the same substrate as the driver for discharging ink, it is necessary to minimize cost increase. It is desirable that the circuit size be small.

In terms of the accuracy of the A / D converter, from the viewpoint of performing ink ejection under a certain ejection characteristic, even a relatively coarse temperature range corresponding to the minimum resolution of about 5 ° C. is sufficiently practical. It is possible to output discrete values that are not continuous at the required temperature because the step size of the temperature is not constant and the temperature step size is not constant, and adopt a circuit with the minimum circuit size as long as such characteristics are satisfied It is desirable. Furthermore, if the power consumption of the A / D converter is large, there is a concern that the substrate temperature rises due to the influence and adversely affects the temperature rise of the whole substrate.
It is desirable to use one with low power consumption as much as possible.

From such a viewpoint, for example, the configuration of the A / D converter as shown in FIG. 9 is suitable as the A / D converter of the present invention.

In FIG. 9, reference numeral 210 denotes a constant current source;
Is a PN junction diode having a linear output voltage characteristic with respect to temperature, 230 is a reference voltage generating circuit having an output voltage characteristic substantially invariant with respect to temperature, 231 is a buffer circuit,
232 is a comparator, 234 is a voltage dividing resistor and an analog switch group for obtaining a voltage corresponding to a desired temperature to be detected from the output of the reference voltage generating circuit, 233 is an output buffer, 236 is a shift register, and 235 is an output. Terminal.

FIG. 10 is a timing chart for explaining the operation of the circuit shown in FIG.

The diode output of 201 supplied with a constant current from 210 has an output voltage characteristic that is linear with respect to temperature. Further, the output voltage characteristic of the reference voltage generation circuit has a substantially invariant characteristic with respect to temperature. By comparing the two with a comparator, the analog output voltage of the diode is converted into a digital value. At this time, if the reference voltage side is set to a voltage corresponding to a desired temperature to be detected by resistance division, a switch connected from a voltage dividing point of the voltage dividing resistor to a shift register that operates in synchronization with a clock pulse. For example, if the diode output generates a voltage having a temperature characteristic of −2 mV / ° C., and the voltage at the voltage dividing point of the resistance voltage dividing is set to 8 at 10 mV intervals, for example, 8 The temperature at the point can be detected from the output of the OUT terminal which changes in synchronization with the clock pulse. This has the same effect as digitally converting a temperature in the range of 40 ° C. with a resolution of 5 ° C.

As shown in FIG. 10, the shift register is provided with a clock input terminal and a reset signal input terminal, and after resetting at a predetermined timing, the output of the OUT terminal is monitored in synchronization with the rising edge of the clock pulse. When the output of the OUT terminal changes from a high (High) level to a low (Low) level at a timing corresponding to a desired temperature, the temperature can be digitally detected.

By adopting such a configuration, for example, if the resolution is relatively coarse in increments of 5 ° C., the substrate for the ink jet recording head has a small circuit configuration including a reference voltage, a comparator, and a resistor corresponding to the number of detected temperature points. An A / D converter can be built on top. Further, since only one reference voltage generation circuit and one comparator are required, the power consumption of the entire circuit can be suppressed, and it is possible to prevent the temperature rise of the substrate from being adversely affected.

Further, if a resistor for monitoring the heater resistance value or a transistor for monitoring the ON resistance of the power transistor is connected to the constant current source instead of the PN-coupled diode, the respective values can be A / D converted at a desired resolution. It is possible to do.

Next, the recording head IJ having the above-described configuration will be described.
The operation of H will be described.

The rise in the substrate temperature due to the heat generated by the recording operation of the recording head IJH has a bad influence on the control for always performing a constant ink discharge as described in the conventional example. Further, variations in the heater resistance values of the individual print heads cause variations in the amount of heat generated by the heaters, and adversely affect ink discharge control after a new print head is replaced.

A power transistor for driving the heater consumes a driving current due to its resistance component, which causes a reduction in the amount of heat generated by the heater. Therefore, a power transistor having as small a resistance component as possible is used. Is preferred. However, no matter how small the resistance component is, it is inevitable that a power loss will occur, and there is also an individual difference between the recording heads, similarly to the heater resistance value. Therefore,
There is also an individual difference in power loss, which eventually appears as a variation in the amount of heat generated by the heater, and consequently has an adverse effect of a variation in the ink ejection characteristics. Therefore, it is necessary to monitor the value of the resistance component of the power transistor in each recording head and perform control for always performing optimal driving.

As described above, typical elements for representing the state of the substrate of the recording head IJH include the substrate temperature, the heater resistance value, and the power transistor ON resistance value.

Elements for monitoring these elements are elements contained in the element block 120, and these elements output their values as analog values. This analog value is sent to the A / D converter 301 and converted into a digital value. These digital values are sent to the determination circuit block 140 via the terminal 131 and the wiring 133. On the other hand, the judgment circuit block 140 receives the output of the digital value and receives the respective states of the substrate 101 (substrate temperature, heater resistance value, power transistor ON resistance value).
And select the optimal drive pulse according to it,
This is fed back to the logic circuit unit 105.

Here, in order to keep the ink ejection state constant, it is necessary to perform optimal driving in accordance with the state of the substrate. This is because the time for flowing current to the heater, that is, the pulse for driving the driver transistor, is required. (Hereinafter, heat pulse)
Is made possible by changing the pulse width. Therefore, after receiving the state of the substrate as a digital value, the head is driven by determining the heat pulse width corresponding to the digital value.

FIG. 11 is a diagram showing a table for determining a heated pulse width corresponding to a change in the temperature state, the heater resistance value, and the transistor ON resistance value within a certain range.

For example, as shown in FIG. 11A, when the resolution of the temperature detection is set to eight levels, the fourth state is set to the standard value of the heat pulse width (Th), and the temperature is increased by one rank from this point. A table is created in which the pulse width is reduced by 2% each time the temperature rises, and the pulse width is increased by 2% each time the temperature decreases by one rank, and this table is stored in the memory in the drive device. After receiving the digital value, the driver transistor is driven using Th obtained from the table.

Further, since the heater and the transistor are connected in series in the substrate, their resistance values are represented by the sum of the two resistance values, so that the pulse width may be determined by the total resistance value. By preparing a table in a matrix format as shown in FIG. 11B, a predetermined Th can be efficiently selected.

In a rank matrix corresponding to resistance values received as digital values, if rank resistance increases, Th
Is increased, and if the rank resistance is reduced, the optimum drive pulse can be determined by reducing Th. In the present embodiment, Th is increased or decreased by 1% in accordance with the increase or decrease of the one-rank resistance, but the amount of increase or decrease may be determined and determined as appropriate.

Therefore, according to the embodiment described above, an A / D converter is provided on the substrate of the recording head, and information reflecting the substrate temperature, the heater resistance value, and the power transistor ON resistance value is converted into a digital signal by the recording apparatus. Since the signal can be output, it is hardly affected by various noises generated from the recording head in association with the recording operation, and the signal can be received with high accuracy.

As a result, it becomes possible to more accurately control the drive of the recording head based on information that more accurately reflects changes in the substrate temperature, the heater resistance value, and the ON resistance value of the power transistor. The recording head can be controlled so that the obtained ink ejection characteristics can be obtained.

In the above-described first embodiment, analog information indicating the characteristics of the substrate temperature, the heater resistance value, and the ON resistance value of the power transistor is read from each terminal of the element block 120 at a certain period, and is read. Is converted into a digital value, and each time the optimum control is fed back to the recording head. However,
Such a control is necessary for a factor that constantly changes due to a change in the driving state of the recording head such as the substrate temperature. For example, when a new recording head is replaced, the value may be read once and stored in the non-volatile memory, and thereafter, the value of the memory may be read.

FIG. 7 shows a recording head IJH according to this modification.
FIG. 4 is a block diagram showing a characteristic portion of the substrate configuration of FIG.

In FIG. 7, reference numeral 311 denotes an element block 12.
0 is an external terminal for measuring the characteristics of each element, 302 is a nonvolatile memory (NVRAM) for storing the measured values of each element, and 312 is a writing terminal for writing to the NVRAM 302.

According to the configuration shown in FIG.
, The resistance in the element block 120 and the ON resistance of the transistor are measured by, for example, a factory inspection of the print head IJH, and a digital value corresponding thereto is written to the NVRAM 302 via the write terminal 312.
If read out from the terminal 131 as needed, a digital value can be easily obtained without measuring the elements of the element block 120.

At this time, specific elements of the NVRAM 302 can be arbitrarily selected according to the required accuracy and the semiconductor process to be used. For example, EPROM, EEPROM, Fu
A se (fuse) ROM or the like is conceivable.

Therefore, according to the above-described modified example, information representing characteristics such as a heater resistance value and a power transistor ON resistance value which do not change with time is stored as digital information in a non-volatile memory provided in the recording head at the time of factory shipment. The information can be read out from the memory and used as needed for drive control of the recording head, and only the information on the substrate temperature that changes over time can be written in the element block 1.
20 and the A / D converter 301 can be periodically read out as digital information.

In the first embodiment and its modifications described above, the characteristics of the substrate temperature, the heater resistance value, and the ON resistance value of the power transistor are represented as elements indicating the state of the substrate housed in the element block 120. Although an element was used, the present invention is not limited to this. For example, a means for monitoring the remaining amount of ink to be ejected, an individual value for the switching speed of each transistor, and a device for monitoring characteristics such as a PH value indicating the acidity and alkalinity of the ink and an external humidity are used. May be.

Further, an element for monitoring an individual value such as a film thickness of a wiring layer and a protective film thickness may be used as an element constituting the substrate.

Since the switching speed of the transistor, the thickness of the wiring layer, the thickness of the protective film, and the like do not change with time, the values measured at the time of shipment from the factory can be written in the nonvolatile memory as described above. It can be digitized.

<Second Embodiment> A recording head according to a second embodiment of the present invention will be described below.

FIG. 12 is a diagram showing an example of a circuit configuration of a recording head formed on the same substrate (on an element substrate) constituting the recording head.

FIG. 12A shows the configuration of a heater driving circuit for driving a heater in accordance with an input image signal.
FIG. 3B shows data (hereinafter referred to as ROM data) indicating resistance variations of switches constituted by power transistors provided corresponding to the heaters, in order to control whether a current flows through each of the heaters. (C) is a configuration of an A / D conversion circuit that analog-inputs the state of the recording head (such as head temperature) and digitally outputs it. FIG.

FIG. 13 is a time chart of various signals input to and output from the recording head shown in FIG. FIG.
12A shows an output signal to the circuit shown in FIG. 12A, FIG. 12B shows an input / output signal of the circuit shown in FIG. 12B, and FIG. 12C shows a circuit shown in FIG. 5 is a time chart showing input / output signals of the first embodiment.

Next, the configuration and operation of the recording head will be described.

First, the ink discharging operation will be described with reference to FIGS. 12 (a) and 13 (a).

As shown in FIG. 12A, a plurality of shift registers (S / R) 1156 are provided corresponding to a plurality of heaters 1150, respectively, and these are connected in series. Shift register (S / R) 11
The output of each of the 56 is connected to a LATCH circuit 1154, and the output of the LATCH circuit 1154 is connected to one input of an AND gate 1152. On the other hand, A
The other input of the ND gate 1152 is a heat signal (HEA
T) is connected to an input pad (PAD) 1153.

The output of the AND gate 1152 controls the opening and closing of the switch 1151 for controlling the energization of the heater 1150. When the switch 1151 is turned on in accordance with the output signal from the AND gate 1152, the heater 1
150 is energized, heats the ink by the heat energy from the heater 1150, and discharges the ink from the discharge nozzle port.

The image signal (DATA) is shown in FIG.
As shown in (a), data is serially input from a data input pad (PAD) 1157 in synchronization with a clock signal (DCLK1) input from an input pad (PAD) 1159. When the input of the image signal to the plurality of shift registers (S / R) 1156 is completed, the input pad (PAD) 115
5, the pulse of the latch signal (LD1) is input, and the image signal (DATA) temporarily held in the plurality of shift registers (S / R) 1156 is collectively captured and held by the LATCH circuit 1154.

The AND gate 1152 is enabled according to the logical product of the level (H / L) of the latched image signal and the level of the heat signal (HEAT) input from the input pad (PAD) 1153. Becomes
As a result, the switch 1151 becomes conductive, and FIG.
A current flows from the VH power supply line shown in FIG. The energization of the heater occurs only where the image signal is at the high level "H", and the energization causes the heater to generate heat and the thermal energy to eject ink. It should be noted that the heater can be turned on only during the time when the pulse of the heat signal (HEAT) is being applied.

Next, the configuration and operation of the ROM data output circuit will be described with reference to FIGS. 12 (b) and 13 (b).

Since the circuit board of the recording head is manufactured by applying a semiconductor manufacturing process, the characteristics of the IC chip include variations that occur during manufacturing. Such variations are
It may also affect the ink ejection characteristics. Therefore,
It is necessary to minimize the influence of such variations on the ink ejection characteristics and to improve the durability of the heater by applying an optimum power to the heater in consideration of the variations.

For this reason, as shown in FIG. 12B, the resistance variation of the heater 1150 generated in the semiconductor manufacturing process and the ON / OFF state of the heater are provided on the circuit board of the recording head.
10 stores information relating to the variation unique to the IC chip, such as the variation in the ON resistance of the switch 1151 to be turned on.
ROM 1114 are provided.

The ROM data output circuit shown in FIG.
As shown in (b), the latch signal (LD2) is input from the input pad (PAD) 1103, and then the clock signal (DCLK2) is input from the input pad (PAD) 1101 to synchronize with the clock signal. ROM data is serially output from the output pad (PAD) 1115 (ROM0, ROM1, ROM2, ROM3,...).
Is output.

As shown in FIG. 12B, ten shift registers (S / R0, S / R1,..., S / R9) 1107 are provided in the ROM data output circuit. The shift registers are provided in a one-to-one correspondence with the ROM 1114. These shift registers are connected in series, and finally, through another shift register (S / R10).
It is connected to PAD1115. In this connection,
Input terminals (IN) and output terminals (OUT) of adjacent shift registers (S / R0 to S / R10) are connected to each other.

FIG. 14 is a circuit diagram showing the internal configuration of each of these shift registers.

The PAD 1101, the clock signal inverted by the inverter 1102, and the PAD 1103 correspond to these shift registers and another shift register (S / R).
10), the data from the ten ROMs 1114 are read in parallel by one pulse of the latch signal (LD2) input from the PAD 1103, and stored in the respective shift registers 1107. You.

Referring to FIG. 12 (b) and FIG. 14, the clock signal (D
CLK2) to the DK terminal of each shift register, the inverted clock signal to the IDK terminal of each shift register, and PA
The latch signal input from D1103 is input to the LD terminal of each shift register. The output signal from the ROM 1114 is input to the RIN terminal of each shift register.

Next, when a clock signal (DCLK2) is input from the PAD 1101, the ROM data is stored in the PAD 111 in synchronization with the rising edge of the clock signal.
5 is output.

FIG. 15 is a diagram showing the internal configuration of each ROM 1114.

The storage element 1138 of each ROM is electrically written externally at the end of the semiconductor manufacturing process. More specifically, the signal level (H
/ L) is determined, or a capacitor using a ferroelectric material holds the signal level (H / L).

Here, the operation of the shift register when the signal level stored in the storage element 1138 shown in FIG. 15 is at the high level “H” and when the signal level is at the low level “L” will be described.

(1) In the case of high level "H" In this case, the signal at the output terminal (OUT) of the ROM becomes low level "L", so that the shift register (OUT) connected to this output terminal (OUT) A low-level “L” signal is input from the RIN terminal of (S / R). However, the signal is not yet held in the shift register (S / R) at this time.

Next, when one pulse of the latch signal (LD2) is input when the clock signal (DCLK2) is at the low level "L", the signal input to the RIN terminal is not shifted to the shift register (S / R). ). According to the logical structure of the shift register shown in FIG. 14, when the signal level at the RIN terminal is "L" and the level of the latch signal (LD2) is "H", the output of the shift register (S / R) is output. The signal level at the terminal (OUT) is kept at "H". As described above, the ten shift registers (S / R0,..., S / R9) are connected in parallel to the ten ROMs 1114, so that all the ROM data is stored in the shift registers (S / R) at the same timing. Transferred to and retained.

(2) In the case of low level “L” In this case, the signal at the output terminal (OUT) of the ROM goes to high level “H”, so that the shift register (OUT) connected to this output terminal (OUT) A high-level "H" signal is input from the RIN terminal of (S / R). However, the signal is not yet held in the shift register (S / R) at this time.

Next, when one pulse of the latch signal (LD2) is input when the clock signal (DCLK2) is at the low level "L", the signal input to the RIN terminal is not shifted to the shift register (S / R). ). Then, the signal level at the RIN terminal is “H”,
When the level of the latch signal (LD2) is "H", the signal level at the output terminal (OUT) of the shift register (S / R) is held at "L".

Even when the signal levels stored in the storage elements of the ten ROMs 1114 are mixed in H / L,
The signal level corresponding to the signal level is similarly held in the shift register (S / R0,..., S / R9).

When the ROM data is transferred and held in the shift register (S / R) in this manner, the ROM data is transferred to the shift register (S / R) in synchronization with the rising edge of the pulse of the clock signal (DCLK2). ) (That is, the parallel data read from the ROM is converted into serial data and output).

Finally, the configuration and operation of the A / D conversion circuit will be described with reference to FIGS. 12 (c) and 13 (c).

Since the recording head ejects ink by applying thermal energy generated by the heat generated by the heater to the ink, the temperature of the recording head itself increases due to the heat generated by the heater. On the other hand, the viscosity of the ink depends on the temperature.
Further, the amount of ejected ink depends on the viscosity of the ink. Therefore, the ink ejection amount is also affected by the temperature of the recording head, that is, the ink temperature.

For this reason, the temperature of the print head is fed back to the CPU of the printing apparatus main body to perform print control in consideration of the ink ejection characteristics due to the temperature change, and further, to prevent the print head from exceeding the allowable temperature due to the heat generated by the heater. It is necessary to control recording. However, since the output of the temperature sensor for measuring this temperature is an analog value, an A / D conversion circuit is required for converting the analog value into a digital value for processing by the CPU.

As described above, such a circuit can be provided on the apparatus main body side. However, as described in the previous embodiment, recording is performed from the viewpoint of simplification of the configuration on the main body side and prevention of noise. A / D conversion is performed inside the head. Also in this embodiment, an A / D conversion circuit is provided on the circuit board of the print head.

This circuit receives an analog signal (ALG) such as an output (a voltage proportional to the temperature) of a temperature sensor provided inside the recording head, compares it with a reference voltage, and digitally outputs the result. This reference voltage is switched to four stages by inputting any one of four signals (IN0 to IN3) via four input pads (PAD) 1316 to 1319.

In FIG. 12C, reference numeral 1124 denotes a temperature,
The constant voltage sources (Vref), 1125 to 1129, which are not affected by the respective fluctuations of the external power supply, are resistors, respectively, and these resistors are connected in series. An arbitrary voltage can be obtained depending on the resistance ratio of each resistor. Also, 1130 to 1133 are input signals (IN0 to IN0).
An analog switch that performs an ON / OFF operation according to 3).

Four input pads (PAD) 1316-1
319 from one of the pads (IN0 to IN0)
When any one of 3) is input, the signal is inverted by the inverters 1120 to 1123, and the input signal and the inverted input signal are changed to the selected analog switch 1130 to 11
33, and the voltage of the node connected to the selected analog switch is applied to the node 1134.
Is input to the (-) terminal of the comparator 1135.

The comparator 1135 uses this as a reference voltage and compares it with the input analog signal (ALG). Then, the comparison result is output from the digital output terminal 1137 as a digital signal.

Next, another embodiment of the recording head of the present invention, which further reduces the number of pads and wirings of such an embodiment, will be described.

FIG. 16 is a diagram showing a configuration of a circuit board mounted on the recording head IJH as such an embodiment.

In FIG. 16, the same components as those of the circuit board of the recording head of the embodiment already described with reference to FIG. 12 are denoted by the same reference numerals, and the same signals are denoted by the same reference symbols. The description thereof will be omitted, and here, the characteristic elements of this embodiment and the operation thereof, particularly, the difference from the circuit of FIG. 12 will be described. 16A shows a heater driving circuit for driving the heater corresponding to FIG. 12A, FIG. 16B shows a ROM data output circuit corresponding to FIG. 12B, and FIG. This is an A / D conversion circuit corresponding to 12 (c). Therefore, the ROM 1114 'shown in FIG.
14 is stored.

Here, unlike the embodiment of FIG. 12, the latch signal (LD) input from the PAD 1103 is supplied to the latch circuit (Latch) 1154 of the heater drive circuit for the shift register (S / R0-9) 1107 '. Commonly used with latch signals. The shift register (S / R) 1156 of the heater drive circuit has a PAD 11
The clock signal (DCLK) input from 01 and its inverted signal are commonly used as the input signal to the shift register (S / R0-9) 1107 '.

FIG. 17 shows a shift register (S / R) 115.
6 is a circuit diagram showing the configuration of FIG. In FIG. 17, DK is a clock signal (DCLK) input terminal, IDK is an inverted clock signal input terminal, and IN is an image signal (DAT).
An input terminal A) and an output terminal OUT for an image signal (DATA).

FIG. 18 shows a latch circuit (Latch) 115.
4 is a circuit diagram showing a configuration of FIG. In FIG. 18, LD is an input terminal of a latch signal (LD), IN is an input terminal of an image signal (DATA) from a shift register (S / R) 1156, and OUT is an output terminal of a latched image signal.

As for the ROM data output circuit,
The output from the output terminal (OUT) of each of the ten shift registers (S / R0 to 9) 1107 'is connected to the input terminal (IN) of the next-stage shift register.
The ROM 1114 'is connected to the address input terminal (IN) of the ROM 1114' so that ten shift registers and ten ROMs are connected as a pair. In the example shown in FIG. 16, a 10-bit shift register is configured. A starter circuit 1140 is connected to the previous stage of the shift register 1107 ', and a PAD 1103 is connected to its LD terminal.
, The latch signal (LD) input from the
The output terminal (O) of the shift register (S / R0) is connected to the N terminal.
UT), and the output signal from the OUT terminal is the input terminal (I / O) of the shift register (S / R0).
N). Furthermore, ten ROMs 111
4 'each output terminal (OUT) is a 10-input OR circuit 11
40. The output of the 10-input OR circuit 1140 is the ROM data output.

FIG. 19 shows one shift register (S / R0).
9 is a circuit diagram showing the configuration of 1107 '. As can be seen from a comparison between FIG. 19 and FIG. 14, the shift register (S / R0-9) 1107 'of this embodiment has no input terminal from the ROM, and the signal from the preceding shift register or starter circuit 1140 is not provided. , An output terminal (OUT) for a signal to a shift register or PAD 1115 at the subsequent stage, a latch signal input terminal (LD), a clock signal input terminal (DK), and an inverted clock signal. An input terminal (IDK).

FIG. 20 is a circuit diagram showing a configuration of starter circuit 1140. In FIG. 20, LD is an input terminal of a latch signal (LD), and IN is a shift register (S / R).
0) an input terminal for a feedback signal from 1107 ';
OUT is an output terminal to the shift register (S / R0) 1107 '.

FIG. 21 is a circuit diagram showing a configuration of ROM 1114 '. 21 and the ROM 11 shown in FIG.
As can be seen from comparison with the configuration of FIG. 14, in the ROM of this embodiment, an AND circuit is provided before the storage element 1138, and a signal input from the shift register to the input terminal (IN) and an output signal level from the storage element 1138 are provided. And is output from the output terminal (OUT).

Furthermore, the first four shift registers (S / R0 to S / R3) of the ten shift registers provided in the ROM data output circuit are supplied to the four inverters 1120 to 1123 of the A / D conversion circuit. ) Output signals from each are input via input nodes 1116 to 1119.

Due to the difference in configuration from the embodiment shown in FIG. 12, the signal transmission path differs as follows.

That is, in the embodiment shown in FIG. 12B, the ROM data is collectively transferred to the shift register of the ROM data output circuit, and the clock signal (DCLK2) is input to the shift register, whereby the serial data is transferred. In contrast to the output, in this embodiment, as shown in FIG. 16, the shift register (S / R0-9) 1107 'is used.
, A high-level "H" signal is input to the first-stage shift register (S / R0) using the starter circuit 1140. Now, the shift register (S
/ R0) is connected to the input terminal (IN) of the corresponding ROM, and the high level "H" is applied to the input terminal of the ROM.
Is applied, the signal (H / L) stored in the storage element of the ROM is output to the output terminal (OUT).

On the other hand, since the output of the shift register (S / R0) is input to the subsequent shift register (S / R1), its output is sequentially output to the subsequent shift register (S / R1).
2, 3,...), And as a result, the data stored in the ROM corresponding to the place where the outputs of these shift registers have become high level “H” are sequentially output.

Further, when the output of the shift register (S / R0) is sequentially transferred to the subsequent shift register, the output of the shift register (S / R0, 1, 2, 3) becomes A / D
Output to the input nodes 1116 to 1119 of the conversion circuit,
It is also used as a reference voltage switching signal.

Next, the operation of the recording head having the above configuration will be described with reference to a time chart shown in FIG.

First, all shift registers (S / R0 to S / R0)
9) To make the signal level stored in 1107 'low level "L", while keeping the signal level of the clock signal (DCLK) "L", the latch signal (LD)
Input one pulse. As a result, the signal from the output terminal (OUT) of the shift register (S / R0-9) 1107 'is fixed and held at the low level "L".

Next, the input signal to the first-stage shift register (S / R0) is set to the high level “H” using the starter circuit 1140. That is, the low level “L” signal is output from the shift register (S / R0) by the input of the latch signal (LD) pulse, and is fed back to the IN terminal of the starter circuit 1140. On the other hand, after the input of the latch signal (LD) pulse, the latch signal (LD) level becomes low level "L". Therefore, according to the configuration of the starter circuit shown in FIG. OUT), a high-level "H" signal is output and held. Then, a high-level "H" signal is applied to the input terminal (IN) of the shift register (S / R0). Thus, when the latch signal (LD) is at the low level (that is, the PAD 110).
3), the output from the starter circuit 1140 is maintained at the high level “H”.

Next, as shown in FIG.
By inputting the pulse of the clock signal (DCLK) from 1, the high-level “H” signal held in the shift register is sequentially shifted to the subsequent shift register.

Here, if the output from the starter circuit 1140 holds the high level "H" permanently, all the shift registers (S / R0-9) hold the high level "H" signal. It will be. Therefore, the high level "H" set in the shift register (S / R0)
(Ie, 1-bit data) are sequentially transferred to the next-stage shift register (S / R1, 2,...), And the output from the shift register (S / R0) is input to the starter circuit 1140. Feedback input is made to the terminal (IN). That is, the input terminal (I
A high-level “H” signal is applied to N). on the other hand,
Since the latch signal (LD) input to the LD terminal maintains the low level “L”, as a result, the signal level of the output terminal (OUT) of the starter circuit 1140 is fixed and held at the low level “L”. Is done.

Therefore, as shown in FIG. 22, a high-level "H" signal (ie, 1-bit data) is successively shifted through the shift registers (S / R0 to S / R9). Now, as described above, the shift register (S / R0
The outputs 9 to 9) are respectively connected to the input terminals of the corresponding ROM. Therefore, the shift register (S / R0-9)
Only when the output is at the high level "H", the ROM becomes readable and the data (H / L data) stored in the storage element is output from the output terminal (OUT). In this manner, the ROM data output from the output terminal (OUT) is input to the 10-input OR circuit 1140.

As described above, the shift registers (S / R0 to S / R0)
Since data is output from the ROM only when the output signal from 9) is at the high level "H", the output from the ROM is serial as shown in FIG.

On the other hand, a shift register (S) is connected to input nodes 1116 to 1119 of the reference voltage switching signal of the A / D conversion circuit.
/ R0 to 3), digital data is output according to the input of the clock signal (DCLK).

Therefore, according to the embodiment described above,
A signal used for ROM data read control is shared with a signal used for heater driving, and digital data output such as internal temperature information of the printhead is performed using a transfer clock (DCLK) of an image signal (DATA). Therefore, the number of control signals input to the print head can be reduced, and the number of input / output pads provided on the circuit board of the print head can be reduced.

As a result, the area of the circuit board of the recording head can be reduced and the circuit board can be simplified, which can contribute to downsizing of the apparatus and cost reduction. Further, the reduction in the number of pads leads to a reduction in the number of pointing wires to external contacts, leading to a cost reduction. Also,
The reduction in the number of control signal lines due to the reduction in the number of pads leads to improvement in device reliability and cost reduction.

In the second embodiment, the output frequency of the digital signal output from the A / D conversion circuit is
As described above, the example in which the output frequency is the same as the output frequency of the ROM data has been described. In the following modified example, a case will be described in which the output frequency of the digital signal is lower than the ROM data output frequency and the digital signal is output.

FIG. 23 shows a recording head IJ according to this modification.
FIG. 3 is a diagram illustrating a configuration of a circuit board mounted on H. In addition,
In FIG. 23, the same components as those of the configuration of the circuit board of the recording head already described with reference to FIGS. 16 and 12 are denoted by the same reference numerals, and the same signals are denoted by the same reference symbols and description thereof is omitted. Here, elements characteristic to this modification and their operations, particularly differences from the above-described embodiment, will be described. In FIG. 23, FIG.
6A shows the same heater drive circuit, FIG. 6B shows the same ROM data output circuit as FIG. 16B, and FIG.
(C) is the same A / D conversion circuit.

Therefore, as apparent from a comparison between FIG. 23 and FIG. 16, a clock rate switching circuit (FIG. 23) is provided between the ROM data output circuit and the A / D conversion circuit on the circuit board of this modification. (D)) is provided.

The configuration and operation of this clock rate switching circuit will be described below with reference to the time charts shown in FIGS.

As shown in FIG. 23, the clock rate switching circuit comprises four pairs of adjacent shift registers ((S / R0 and S / R1), (S / R2 and S / R3), and (S / R4 and S / R3).
/ R5) and (S / R6 and S / R7))
By inputting to the R gates 1260 to 1263, the signal output frequency from the shift register synchronized with the clock signal (DCLK) is doubled (（) as shown in FIG. The outputs of these OR gates are connected to input nodes 1116 to 1119 of the reference voltage switching signal, and the input analog signal (ALG) is converted into a digital signal according to the selected reference voltage, as in the second embodiment. The data is converted to data and output from the PAD 1137.

With the above-described configuration, in this modification, the A / D conversion can be performed while reducing the speed required for the operation of the comparator 1135. Normal,
Increasing the switching speed of the comparator, that is, increasing the operating frequency, increases the power consumption of the circuit. Therefore, it is desirable to minimize the heat generated by the circuit in order to maintain the normal operation of the recording head.

Therefore, according to the modified example of the second embodiment described above, the switching speed of the comparator can be reduced to control the rise in the temperature of the circuit board, so that the good operation of the recording head can be maintained.

It is needless to say that the switching speed of the comparator can be further reduced by setting the number of output signals of the shift register input to one OR gate to two or more.

<Third Embodiment> Hereinafter, a third embodiment of the recording head of the present invention will be described.

FIG. 24 is a block diagram schematically showing the electrical connection between the recording head according to the present embodiment and the control unit 9100 of the recording apparatus main body. Here, only signals related to data transfer are shown for simplification of description.

In this figure, reference numeral 9000 denotes a semiconductor substrate (element substrate) which forms a part of a recording head, and controls ejection of one color ink. Reference numeral 9001 denotes a shift register, which is a recording data signal HDATA,
Data transferred by the transfer clock HCLK and the latch signal BG are latched and supplied to the driving logic circuit 9002.

The drive logic circuit 9002 drives an electrothermal transducer (heater) inside the nozzle 9003 in accordance with data from the shift register 9001 to discharge ink according to a discharge control signal (not shown). Reference numeral 9004 denotes a temperature detection unit which changes an output signal level in an analog manner according to the temperature of the semiconductor substrate 9000. Reference numeral 9005 denotes a comparator, which sequentially switches a plurality of reference voltages, compares the reference voltages with the output of the temperature detection unit 9004, and outputs a comparison result as digital signal “1” or “0” as a signal TO.

Reference numeral 9006 denotes a fuse ROM which stores a plurality of bits of information indicating an identification (ID) and / or a rank written in advance by fusing a resistor as a memory for storing information relating to a recording head, and sequentially switches pointers. Then, the stored information is converted into a signal SO bit by bit.
Output to

The memory format is a fuse type ROM.
However, other types of nonvolatile memories such as an EPROM and an EEPROM can be used.

FIG. 25 is a timing chart showing the states of the HDATA, HCLK, and BG signals when only the recording data is transferred. Here, “f0cah”
A case where 16-bit recording data (1111000011001010B) is transferred is shown.

At each rising edge of HCLK, HDATA
(1 bit data of “1” or “0”) is input to the shift register 9001 and simultaneously the head control unit 2
018 switches the data output from HDATA to the next bit data. After repeating this, 16-bit data is input to the shift register 9001, and at the rising edge when the BG once becomes “Low” and becomes “High” again, the 16-bit data is latched in the shift register unit 9001.

FIG. 26 is a flowchart showing the reference voltage switching operation in comparator 9005. First, it is determined whether or not the signal BG is “1” (step S931). If the signal BG is “1”, the reference voltage level is returned to the initial level “1” (step S93).
2). If the signal BG is “0” in step S931,
It is determined whether the rising edge of HCLK is detected (step S933). If the rising edge of HCLK is detected, the reference voltage level is incremented (step S933).
934), and returns to step S931.

That is, in the state of BG = "0", HCL
Each time the rise of K is detected, the reference voltage level is increased. Then, information on the temperature of the semiconductor substrate 9000 of the recording head is obtained from the number of rising edges (the number of pulses) of HCLK detected from when BG = “1” until the output signal TO of the comparator 9005 changes. be able to.

FIG. 27 is a flowchart showing a pointer switching operation in fuse ROM 9006. First, it is determined whether or not the signal BG is “1” (step S941). If the signal BG is “1”, the position of the pointer is returned to the initial state “1” (step S942). If the signal BG is “0” in step S941, HCLK
It is determined whether or not the rising edge has been detected (step S9).
43) If a rising edge of HCLK is detected, the pointer is incremented (step S944), and the process returns to step S931.

That is, in the state of BG = "0", HCL
Each time a rising edge of K is detected, the pointer is incremented, data is output from the ROM 9006 one bit at a time as a signal SO, and a plurality of bits of information indicating the ID and / or rank of the recording head are serially output.

FIG. 28 is a timing chart showing the state of each signal when transfer of print data to the print head and transfer of data from the print head are performed simultaneously. The recording data transferred here is the same as that shown in FIG.

In this case, FIG.
Unlike BG, BG is "0" during the transfer period of the recording data. As a result, the information on the temperature of the print head and the ID and / or rank information are simultaneously output from the semiconductor substrate 9000 of the print head simultaneously with the transfer of the print data. When the signal BG rises to latch the transferred recording data, the signals TO and SO
Returns to the initial value.

As described above, in the present embodiment, the print data transferred to the printhead is 16 bits, and the information transferred from the printhead by the signals SO and TO is also 1 bit.
6 bits. If the recording data is 32 bits, the information that can be transferred from the recording head also has 32 bits. If the information transferred from the recording head is smaller than the number of bits of the recording data, control such as shifting the falling timing of the signal BG later is also possible.

<Fourth Embodiment> Hereinafter, a fourth embodiment of the recording head of the present invention will be described.

FIG. 32 is a block diagram showing a circuit configuration formed on an element substrate constituting a recording head capable of transmitting detected temperature data to the outside in synchronization with input recording data.

In the circuit shown in FIG. 32, the recording data (SD) is input to the shift register (SR) 2101 as serial data in synchronization with the shift clock signal (CK) and is temporarily stored, and further stored. The recorded data is latched by a latch circuit (LT) 2102. Then, based on the latched recording data,
The heater (HT) 2103 is energized and heated.

On the other hand, the same shift clock signal (CK) is used as a switching circuit (SW) 2 for controlling a reference voltage generator (RF) 2104 constituting a temperature detecting circuit provided on a circuit board.
The reference voltage is input to the switch 105 and is used to change the reference voltage every clock. Then, a comparator (CP) 2106
Compares the reference voltage with the output voltage from the temperature detection sensor (DT) 2107 placed near the heater (HT), and compares the comparison result as digital data of “0” or “1” outside the element substrate. Send to

According to such a temperature detection method, as described above, since the detected temperature information is immediately digitized and transmitted, the wiring route between the recording head and the recording apparatus on which the recording head is mounted. Resistant to the effects of noise
In addition, there is no need to provide a circuit such as an A / D converter outside the recording head, and there is no timing loss for acquiring information because transfer of recording data and acquisition of temperature data can be performed simultaneously. There is.

FIG. 29 is a schematic view of a circuit board (element substrate) surface of a recording head IJH in which the embodiment of FIG. 32 is further improved.

Referring to FIG. 29, reference numeral 2001 denotes a circuit board;
002 is a heater array configured to heat ink, which is composed of two rows;
Reference numeral 2003 denotes a logic circuit unit on which a shift register and a latch circuit are mounted. Reference numeral 2004 denotes a contact pad array that presses against a contact in the carriage HC when the print head IJH is mounted on the carriage HC of the printing apparatus. It is a temperature detection circuit section including a sensor for detecting a temperature.

FIG. 30 is a block diagram showing a configuration of a circuit mounted on a circuit board of a print head. FIG. 31 is a time chart of various signals handled by the circuit shown in FIG. In FIG. 30, the same components and signals as those described in the embodiment of FIG. 32 are denoted by the same reference numerals and symbols, and description thereof will be omitted. FIG. 31 shows, for comparison, a signal (TMP) indicating the detected temperature information output from the circuit shown in the embodiment of FIG.

Comparing the configuration shown in FIG. 30 with the configuration shown in FIG. 32, in the embodiment shown in FIG. 30, the frequency of the shift clock signal (CK) input to the preceding stage of the reference voltage switching circuit (SW) 2105 is divided. A frequency dividing circuit (DV) 2000 that obtains a clock signal (CK_DV) by using the frequency dividing circuit is provided.

In the above configuration, as shown in FIG. 31, when a shift clock signal (CK) is input, the frequency of the frequency dividing circuit (DV) 2000 is divided by two, and Is doubled clock signal (CK_D
V). Thereby, the reference voltage switching circuit (S
W) 2105 is a clock signal (CK_D) divided by 2
In accordance with V), a switching operation for changing the reference voltage is performed. By doing so, the comparator (CP) 2106
The operation speed at which the output from the temperature sensor is compared with the reference voltage is also halved.

Therefore, a signal (TMP_SLOW) indicating the detected temperature information output from the comparator (CP) 2106
As shown in FIG. 31, TS1 and TS1 are output once every two clocks of the original shift clock signal (CK).
TS2,... Are transmitted. In this case, information on the detected temperature can be obtained at a speed that is one half of the input speed of the recording data. This is a signal (TM) indicating the information of the conventional detected temperature.
P) is one half of the sending speed.

On the other hand, recording data (SD) is input to the shift register (SR) 2101 as D1, D2, D3,... According to the frequency of the shift clock signal (CK).

Therefore, according to the above-described embodiment, the temperature information can be obtained at one half of the input speed of the recording data. Therefore, even if the input speed of the recording data is doubled, the temperature information can be obtained at the same speed as the conventional one. Obtainable. This makes it possible to cope with a higher recording speed by increasing the input speed of the recording data. On the other hand, it becomes possible to operate the analog circuits of the comparator and the switching circuit at the same speed as in the past, so that the consumption of the analog circuit is reduced. There is no increase in power. Also, there is no need to increase the speed of the analog circuit.

In the embodiment described above, an example was described in which the input shift clock signal was divided by 2, but the present invention is not limited to this. For example,
A clock signal having a frequency divided by three or divided by four may be generated by a frequency dividing circuit.

<Other Embodiments> The four embodiments described above can be applied independently of each other, but some embodiments can also be applied in combination. For example, A / D in the second to fourth embodiments
As in the first embodiment, the converter was formed with an electrothermal conversion element for generating thermal energy, a drive circuit for driving the electrothermal conversion element, and a sensor for detecting the temperature of the substrate. The second and third substrates may be provided on the same substrate (on the element substrate) by a semiconductor manufacturing process.
In the fourth embodiment, the clock signal used for reading from the memory may be obtained by dividing the frequency of the clock used for inputting the recording data, as in the fourth embodiment.

In the above embodiment, the description has been made assuming that the droplets ejected from the recording head are ink, and that the liquid stored in the ink tank is ink. It is not limited. For example, an ink tank may contain a processing liquid discharged to a recording medium in order to improve the fixability and water resistance of the recorded image or to improve the image quality.

The above-described embodiment is particularly provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection even in an ink jet recording system. By using a method in which a change in the state of the ink is caused by energy, it is possible to achieve higher density and higher definition of recording.

The typical structure and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding the film boiling to the electrothermal transducer arranged corresponding to the sheet or the liquid path holding the Since thermal energy is generated in the electrothermal transducer and film boiling occurs on the heat-acting surface of the recording head, bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis can be formed. It is valid. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of the liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, A configuration using U.S. Pat. No. 4,558,333 or U.S. Pat. No. 4,459,600, which discloses a configuration in which a heat acting surface is arranged in a bent region, is also included in the present invention. In addition, for multiple electrothermal transducers,
JP-A-59-123670 which discloses a configuration in which a common slot is used as a discharge part of an electrothermal transducer, and JP-A-59-123670 which discloses a configuration in which an opening for absorbing a pressure wave of thermal energy corresponds to a discharge part. A configuration based on 138461 may be adopted.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is determined by a combination of a plurality of recording heads as disclosed in the above specification. This may be either a configuration satisfying the above requirements or a configuration as a single recording head formed integrally.

In addition to the cartridge type recording head in which the ink tank is provided integrally with the recording head itself described in the above embodiment, the recording head is electrically connected to the apparatus main body by being mounted on the apparatus main body. A replaceable chip-type recording head, which enables a simple connection and supply of ink from the apparatus main body, may be used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like to the configuration of the printing apparatus described above, since the printing operation can be further stabilized. Specific examples thereof include capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof. It is also effective to provide a preliminary ejection mode for performing ejection that is different from printing, in order to perform stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be a single recording head or a combination of plural recording heads. Alternatively, the apparatus may be provided with at least one of full colors by color mixture.

In the above-described embodiment, the description has been made on the assumption that the ink is a liquid. However, even if the ink solidifies at room temperature or lower, the ink that softens or liquefies at room temperature is used. Or, in the ink jet method, generally, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range.
It is sufficient that the ink is in a liquid state when the use recording signal is applied.

In addition, in order to positively prevent the temperature rise due to thermal energy as energy for changing the state of the ink from the solid state to the liquid state,
Alternatively, in order to prevent evaporation of the ink, an ink which solidifies in a standing state and liquefies by heating may be used. In any case, the application of heat energy causes the ink to be liquefied by application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, as described in JP-A-54-56847 or JP-A-60-71260, the ink is held in a liquid state or a solid state in the concave portion or through hole of the porous sheet. It is good also as a form which opposes an electrothermal transducer. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition to the above, the recording apparatus according to the present invention may be provided not only as an image output terminal of an information processing apparatus such as a computer but also integrally or separately, a copying apparatus combined with a reader or the like, and a transmission / reception apparatus. It may take the form of a facsimile machine having functions.

The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but it can be applied to a single device (for example, a copying machine, a facsimile machine). Etc.).

An object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or the apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0236]

As described above, according to the first aspect of the present invention, all the outputs from the elements for detecting the status of the recording head are digitized on the substrate and then output as digital information to the outside. Therefore, for example, information representing the temperature of the substrate, the resistance value of the electrothermal transducer, the ON resistance of the power transistor that drives the electrothermal transducer, and the like are sent as digital values from the recording head to an external recording device. , Power supply noise, G
The signal reading accuracy is improved without being easily affected by ND noise, coupling noise, radiation noise, and the like, and thereby there is an effect that accurate recording head drive control that is not affected by noise can be performed.

On the recording apparatus side, an A / D converter for converting an analog output from a recording head into digital information is unnecessary in the related art.

Further, since noise removing means for reducing power supply noise and GND noise is not required, simplification and space saving of the whole apparatus can be expected.

According to the second aspect of the present invention, the reading of the recording characteristics of a plurality of recording elements for ejecting ink stored in the memory and the conversion of analog signals into digital data are performed by a plurality of recording elements. Can be performed by using a clock signal or a latch signal of a recording signal used to drive the recording head, so that the number of signals input to the recording head can be reduced, and the number of pads required for the signal input can be reduced. This has the effect.

As a result, the size of the recording head circuit board can be reduced, and the production cost of the circuit can be reduced as the size and the number of pads are reduced.

Further, as the number of signals input to the recording head is reduced, the number of signal lines is reduced, so that the occurrence of noise is suppressed. Further, the occurrence of noise can be prevented from suppressing the generation of noise, and the recording head can be prevented from malfunctioning. Can be operated with high reliability.

Further, according to the third aspect of the present invention, information from a recording head can be serially output as a digital signal in synchronization with a clock used for transferring recording data. This eliminates the need to provide a D / A converter on the apparatus main body side, and does not increase the number of signal lines even if the amount of information to be transmitted increases. Therefore, there is no increase in size and cost of the device, and there is only one clock signal serving as a noise source, and there is little influence on the environment. Moreover, stable head information transfer by digital transfer becomes possible.

Also, at the same time as recording, information can be obtained without limiting the data transfer time, so that high-speed recording and fine control using information transferred from the recording head become possible.

Further, according to a fourth aspect of the present invention,
While the recording data is input to the shift register in accordance with the clock of the first frequency for the recording operation, the clock of the first frequency is divided to generate the clock of the second frequency, and the temperature inside the recording head is detected. Since the temperature detection circuit outputs a signal indicating the detected temperature in accordance with the clock of the second frequency, the output of the signal indicating the detected temperature is low even if the input speed of the recording data is increased due to the recording operation. Since it is suppressed, the operation speed of the circuit for temperature detection may be slow.

As a result, it is not necessary to increase the speed of the circuit for detecting the temperature in correspondence with the high-speed transfer of the recording data, and it is possible to suppress the cost required for the increase in the speed.

Therefore, it is possible to achieve both the temperature control of the recording head and the high-speed transfer of the recording data without increasing the cost.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an outline of a configuration of an inkjet printer IJRA which is a typical embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a control circuit of the inkjet printer IJRA.

FIG. 3 is an external perspective view illustrating a configuration of an ink cartridge IJC in which an ink tank and a head are separable.

FIG. 4 is a block diagram illustrating a configuration of a printhead substrate according to the first embodiment.

FIG. 5 is a circuit diagram of an element block.

FIG. 6 is a block diagram showing a relationship between an A / D converter and element blocks.

FIG. 7 is a block diagram showing a relationship between an A / D converter, an element block, and a nonvolatile memory according to a modified example.

FIG. 8 is a block diagram of a recording head substrate for explaining a conventional example.

FIG. 9 is a diagram showing a configuration of an A / D converter.

FIG. 10 is a timing chart for explaining the operation of the circuit shown in FIG. 9;

FIG. 11 shows a temperature state, a heater resistance value, and a transistor ON.
FIG. 9 is a diagram illustrating a table for determining a heated pulse width corresponding to a change in the resistance value within a certain range.

FIG. 12 is a diagram illustrating a circuit configuration of a recording head formed on the same substrate.

13 is a time chart of various signals input / output to / from the recording head shown in FIG.

FIG. 14 is a circuit diagram showing an internal configuration of each shift register.

FIG. 15 is a diagram showing an internal configuration of each of ROMs 1114.

FIG. 16 is a diagram illustrating a configuration of a circuit board mounted on a printhead IJH according to a second embodiment.

FIG. 17 is a circuit diagram showing a configuration of a shift register (S / R) 1156.

FIG. 18 is a circuit diagram showing a configuration of a latch circuit (Latch) 1154.

FIG. 19 shows one shift register (S / R0 to 9) 11
It is a circuit diagram which shows the structure of 07 '.

FIG. 20 is a circuit diagram showing a configuration of a starter circuit 1140.

FIG. 21 is a circuit diagram showing a configuration of a ROM 1114 '.

FIG. 22 is a time chart showing various control signals related to the operation of the recording head.

FIG. 23 is a diagram illustrating a configuration of a modified example of the circuit board mounted on the recording head IJH.

FIG. 24 is a block diagram illustrating a connection between a recording head and a head control unit according to the third embodiment.

FIG. 25 is a timing chart when transferring print data.

FIG. 26 is an operation flowchart of the comparator.

FIG. 27 is an operation flowchart of the fuse ROM.

FIG. 28 is a timing chart when print head information is transmitted together with print data.

FIG. 29 is a schematic diagram of a circuit board surface of a printhead IJH of a fourth embodiment.

FIG. 30 is a block diagram illustrating a configuration of a circuit mounted on a circuit board of a printhead.

FIG. 31 is a time chart of various signals handled by the circuit shown in FIG. 30;

FIG. 32 is a block diagram illustrating a circuit configuration of a recording head.

[Explanation of symbols]

Reference Signs List 101 semiconductor substrate 102 heater array 120 element block 130 A / D conversion circuit 140 determination circuit block 1101, 1103, 1153, 1155, 1157,
1316 to 1319, 1358 Input pad 1115, 1137 Output pad 1102, 1120 to 1123 Inverter 1107, 1107 ', 1156 Shift register 1114, 1114' ROM 1116 to 1119 Input node 1124 Constant voltage source 1125 to 1129 Resistance 1130 to 1133 Analog switch 1135 Comparator 1138 Storage element 1139 OR gate 1140 Starter circuit 1150 Heater 1151 Switch 1152 AND circuit 1154 Latch circuit 1260-1263 OR gate 2000 Divider circuit (DV) 2001 Circuit board 2002 Heater row 2003 Logic circuit section 2004 Contact pad row 2005 Temperature detection circuit Section 2101 shift register (SR) 2102 latch circuit (LT) 2103 (HT) 2104 Reference voltage generator (RF) 2105 Switching circuit (SW) 2106 Comparator (CP) 2107 Temperature detection sensor (DT) 9000 Recording head semiconductor substrate 9001 Shift register 9002 Drive logic 9003 Nozzle 9004 Temperature detector 9005 Comparator 9006 Fuse ROM

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Takashi Yoshida 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Kazuki Ota 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term (reference) 2C056 EA23 EA24 EB07 EB29 EB30 EC28 FA03 HA05 HA09 HA51 2C057 AF34 AF82 AG46 AG83 AK02 AK05 AK09 AL11 AL25 AR14 AR20 BA03 BA13

Claims (43)

[Claims] 1. A recording apparatus in which an electrothermal conversion element for generating thermal energy used for discharging ink and a drive circuit for driving the electrothermal conversion element are provided on the same element base. A head for detecting a state of the element base and outputting an analog output; and an A / A for converting the analog output of the sensor to a digital value.
A recording head, comprising: a D converter; wherein the sensor and the A / D converter are provided on the element substrate. 2. The drive circuit, comprising: a power transistor for driving the electrothermal transducer; a shift register for temporarily storing recording data for driving the power transistor; and a recording stored in the shift register. 2. The recording head according to claim 1, further comprising a latch circuit for latching data. 3. The device according to claim 2, wherein the state of the element substrate includes at least one of a temperature of the element substrate, a resistance value of the electrothermal transducer, and an ON resistance value of the power transistor. The recording head as described. 4. The sensor according to claim 1, wherein the sensor has a known pn junction diode having a known temperature characteristic for detecting a temperature of the element substrate.
The same material as the electrothermal converter to detect the resistance value of the electrothermal converter, a resistor formed by the same process, and the same conductive type as the power transistor to detect the ON resistance of the power transistor 4. The recording head according to claim 3, wherein the recording head comprises transistors formed by the same process. 5. A nonvolatile memory for storing digital information representing a resistance value of the electrothermal transducer and digital information representing an ON resistance of the power transistor, further comprising a nonvolatile memory on the element base. The recording head according to claim 4. 6. The nonvolatile memory according to claim 1, wherein the nonvolatile memory is an EPROM,
6. The recording head according to claim 5, comprising at least one of an EPROM and a fuse ROM. 7. The nonvolatile memory stores digital information indicating a resistance value of the electrothermal transducer measured at the time of shipment from a factory and digital information indicating an ON resistance of the power transistor. The recording head according to claim 5. 8. A recording apparatus for performing recording using the recording head according to claim 1, wherein the digital information is output from the sensor and converted to a digital value. And a control unit for controlling the driving of the printhead based on the control. 9. A head cartridge, comprising: the recording head according to claim 1; and an ink tank that stores ink to be supplied to the recording head. 10. A recording apparatus in which an electrothermal transducer for generating thermal energy used for discharging ink and a drive circuit for driving the electrothermal transducer are provided on the same element substrate. A head element substrate, a sensor for detecting a state of the substrate and outputting an analog output, and an A / A for converting an analog output of the sensor into a digital value
A recording head element substrate, comprising: a D converter; wherein the sensor and the A / D converter are provided on the substrate. 11. The driving circuit, comprising: a power transistor for driving the electrothermal transducer; a shift register for temporarily storing recording data for driving the power transistor; and a recording stored in the shift register. 11. The printhead element substrate according to claim 10, further comprising a latch circuit for latching data. 12. The substrate according to claim 11, wherein the state of the substrate includes at least one of a temperature of the substrate, a resistance value of the electrothermal converter, and an ON resistance value of the power transistor. Printhead element substrate. 13. The sensor is a pn junction diode having a known temperature characteristic for detecting the temperature of the substrate, and the same material as the electrothermal converter for detecting a resistance value of the electrothermal converter. And a transistor formed of the same conductive type as that of the power transistor and formed of the same process to detect the resistance formed by the same process and the ON resistance of the power transistor. 13. The printhead element substrate according to item 12. 14. A non-volatile memory for storing digital information indicating a resistance value of the electrothermal transducer and digital information indicating an ON resistance of the power transistor, further comprising: a non-volatile memory on the substrate. Item 14. A recording head element substrate according to item 13. 15. The nonvolatile memory according to claim 1, wherein the nonvolatile memory is an EPROM,
15. The printhead element substrate according to claim 14, comprising at least one of an EEPROM and a fuse ROM. 16. The nonvolatile memory stores digital information indicating a resistance value of the electrothermal transducer measured at the time of shipment from a factory and digital information indicating an ON resistance of the power transistor. The printhead element substrate according to claim 14. 17. A recording head for performing recording by discharging ink according to an ink jet method, comprising: a memory storing recording characteristics of a plurality of recording elements for discharging ink; and converting an analog signal into digital data and outputting the digital data. A conversion circuit; and a drive circuit that drives the plurality of print elements in accordance with a print signal input thereto. And a digital signal output from the conversion circuit using the clock signal. 18. Each of a plurality of printing elements driven by the drive circuit includes a heater, a switch for controlling on / off of energization of the heater, and a discharge nozzle for discharging ink heated by heat generated from the heater. 18. The recording head according to claim 17, comprising: 19. The recording head according to claim 18, wherein said drive circuit has a shift register and a latch circuit. 20. The drive circuit, comprising: a first input pad for inputting a heat pulse signal to the heater; a second input pad for inputting a recording signal to the shift register; and inputting the clock signal. 20. The recording head according to claim 19, further comprising: a third input pad; and a fourth input pad for inputting a latch signal to the latch circuit. 21. The memory, comprising: a plurality of ROMs; and a plurality of shift registers corresponding to the plurality of ROMs in a one-to-one correspondence, and according to the clock signal input from the third input pad. A plurality of shift registers;
21. The recording head according to claim 20, wherein a read signal is output to each of the OMs, and information stored in each of the plurality of ROMs is serially output. 22. The conversion circuit according to claim 21, wherein the conversion circuit receives the read signals output from the plurality of shift registers and generates a threshold signal for performing analog / digital conversion. Recording head. 23. The recording head according to claim 22, wherein the conversion circuit includes a reduction circuit for reducing a frequency of the read signal output from the plurality of shift registers. 24. The recording head according to claim 23, wherein the conversion circuit performs analog / digital conversion on the analog signal according to the frequency reduced by the reduction circuit. 25. The printhead according to claim 17, wherein the analog signal is an output from a temperature sensor that measures an internal temperature of the printhead. 26. A recording apparatus using the recording head according to claim 17. 27. A printhead that performs printing in accordance with an input print signal, comprising: a non-volatile memory storing information regarding the printhead; and information stored in the memory for inputting the print signal. A printhead comprising: output means for outputting a serial signal to an external device within a period in which the print signal is input, using a clock signal and a latch signal to be used. 28. Converting information relating to the state of the recording head into digital data, and converting the converted digital data using a clock signal and a latch signal used to input the recording signal, 28. The recording head according to claim 27, further comprising a conversion unit that outputs the data to the outside in a serial format within the input period. 29. The recording head according to claim 27, wherein the non-volatile memory stores identification information of the recording head. 30. The nonvolatile memory, comprising: an EPROM;
30. The recording head according to claim 27, comprising at least one of an EEPROM and a fuse ROM. 31. A recording head according to claim 27, wherein said output means outputs information stored in said memory bit by bit in synchronization with said clock signal. 32. The recording head according to claim 27, wherein the recording head is an ink jet recording head that performs recording by discharging ink. 33. The recording head, which ejects ink using thermal energy, comprises a thermal energy converter for generating thermal energy to be applied to the ink. Item 33. The recording head according to item 32. 34. The printhead according to claim 33, wherein the information on the state of the printhead is information on a temperature of a portion where the thermal energy converter is provided. 35. A recording apparatus using the recording head according to claim 27. 36. A print head capable of outputting temperature information in accordance with input of print data, comprising: a shift register for inputting print data in accordance with a clock of a first frequency; A temperature detecting circuit for detecting a temperature inside the recording head; and a frequency dividing circuit for dividing a frequency of the clock of the first frequency to generate a clock of a second frequency. 2. A recording head which outputs a signal indicating a detected temperature in accordance with a clock having a frequency of 2. 37. The temperature detection circuit, comprising: a temperature sensor; a reference voltage generation circuit that generates a reference voltage; a switching circuit that changes the reference voltage in accordance with a clock of the second frequency; 37. The recording head according to claim 36, further comprising: a comparison circuit that compares an output voltage with a reference voltage from the switching circuit and outputs the comparison result as a signal indicating the detected temperature. 38. The recording head according to claim 36, wherein the frequency dividing circuit divides the clock of the first frequency by two. 39. The print head according to claim 36, further comprising a latch circuit for latching print data stored in the shift register. 40. The recording head according to claim 36, wherein the recording head is an inkjet recording head that performs recording by discharging ink. 41. The ink jet recording head according to claim 40, further comprising a thermal energy converter for generating thermal energy to be applied to the ink in order to discharge the ink using thermal energy. A recording head according to claim 1. 42. A recording apparatus using the recording head according to claim 36. 43. A recording cartridge comprising the recording head according to claim 17, and an ink tank for storing ink to be supplied to the recording head.