JPH10296964A - Recording head, recorder using the head, and recording head cartridge using the head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording head for detecting a connecting fault between the head and a recorder and the recorder using the head without lowering reliability of electric connection of the head to the recorder without increasing a cost of the recorder. SOLUTION: In the case of mounting the recording head at the carriage, a sheet resistance of a resistor of the head is measured from a resistance value between a Vss terminal and a Rank terminal. Further, a control signal (block enable signal) for generating a block selection signal is input from a terminal to drive an NMOS transistor 307. Then, overall resistance of the ON resistance value of the transistor and the sheet resistance value is measured from a resistance value between the Vss terminal and Rank terminal. An electric connection of an electric contact of at least the recorder to the Vss terminal and Rank terminal of the head is confirmed according to the measured result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head, a recording apparatus using the recording head, and a recording head cartridge using the recording head, and more particularly, to recording by discharging ink in accordance with an ink jet system and the recording head. And a recording head cartridge using the recording head.

[0002]

2. Description of the Related Art A recording head for performing recording in accordance with an ink jet system is disclosed in, for example, Japanese Patent Application Laid-Open No.
Is different from other ink jet recording methods in that thermal energy is applied to a liquid (ink) to cause film boiling, which is used as a driving force for discharging ink droplets. Has features.

That is, according to the recording method disclosed in the above-mentioned publication, the liquid which has been subjected to the action of thermal energy is overheated to generate bubbles, and the liquid is provided to the recording head by the action force based on the generation of the bubbles. Droplets are ejected from the ink ejection ports (orifices), and the droplets adhere to the recording medium, whereby information is recorded by a set of the attached dots.

A recording head employing this recording method generally comprises an orifice provided for discharging liquid, and a thermal element which is in communication with the orifice and which applies thermal energy for discharging liquid droplets to the liquid. The liquid discharge unit includes a liquid discharge unit having a liquid flow path having a part of an action unit, a heat generating resistor serving as a heat converter as a means for generating thermal energy, and an upper protective layer for protecting the heat generating resistor from ink.

[0005] By the way, many print heads employing the recent ink jet system are detachable from a carriage of a printing apparatus and are often replaced by a user as appropriate. In the case of this type, an electric contact for driving a heater in the print head is connected to an electric contact of the printing apparatus (carriage side) at the same time when the user mounts the print head on the carriage.

[0006] The heater mounted in the print head is driven from the outside (printing apparatus main body). However, when the number of heaters to be driven increases and the number of electrical contacts between the print head and the printing apparatus increases, Connection reliability is reduced. According to Japanese Patent Application Laid-Open No. 57-72867, an element for driving a heater and a logic circuit for controlling the driving circuit are mounted on the same substrate in a print head in order to improve reliability regarding this problem. By doing so, the number of electrical contacts between the recording head and the recording apparatus was reduced.

In this way, even if the number of heaters in the recording head increases, the number of electrical contacts is suppressed to about 30 to 40, and the reliability is improved.

[0008]

However, when both a heater driving circuit and a logic circuit for controlling the heater are mounted in the printhead as in the above-mentioned conventional example, the electrical connection between the printhead and the printing apparatus is reduced. If a connection failure causes a connection failure of a terminal for inputting a signal to the logic circuit, the heater may operate abnormally and the heater may be destroyed.

In order to solve this problem, it is conceivable to provide a function of checking the terminals one by one after the recording head is mounted on the carriage of the recording apparatus.
Such a solution introduces a new problem of increasing the cost of the recording device. In addition, a method of providing a check electrical contact between the recording head and the recording device to detect a connection failure can be considered, but this method increases the number of electrical contacts between the recording head and the recording device. As a result, there is a problem that the reliability of the connection is reduced.

[0010] The present invention has been made in view of the above conventional example, and does not cause an increase in the cost of the recording apparatus.
Recording head capable of detecting poor connection between recording head and recording apparatus without reducing reliability of electrical connection between recording head and recording apparatus, recording apparatus using the recording head, and recording head using the recording head It is an object of the present invention to provide a recording head cartridge using the same.

[0011]

To achieve the above object, a recording head according to the present invention has the following arrangement.

That is, a recording head that heats ink and discharges the ink to perform recording, wherein a plurality of resistors for heating the ink and a plurality of powers for energizing and driving the plurality of resistors are provided. A transistor, a selection circuit for dividing and selecting the plurality of power transistors, a first terminal for inputting a control signal for performing division selection of the power transistor in the selection circuit, and measuring a sheet resistance value of the resistor Resistance, a second terminal electrically connected to the sheet resistance for measuring the sheet resistance, and the same characteristics as the plurality of power transistors connected in parallel to the sheet resistance. And a third terminal to which one terminal of the plurality of power transistors and one terminal of the transistor are connected in common, ON resistance of the transistor is determined by the output from said second terminal, said transistor comprises a recording head, characterized in that it is driven based on a control signal inputted from the first terminal.

According to still another aspect of the present invention, there is provided a recording apparatus for performing recording using the exchangeable recording head having the above-described structure, wherein the scanning means for reciprocating the recording head, and at least the first, second, and second recording means. An electrical contact for making an electrical connection with the recording head via a third terminal; and when the recording head is mounted on the scanning means, at least the sheet resistance is set to the second terminal and the third terminal. The control signal is input from the first terminal to drive the transistor, and the total resistance between the ON resistance value of the transistor and the sheet resistance value is measured from the second terminal. Measuring means for measuring from a resistance value between the first and third terminals, and confirming means for confirming at least an electrical connection between the electrical contact and the first and third terminals according to a measurement result by the measuring means. A recording apparatus characterized by having a.

According to still another aspect of the present invention, there is provided a printhead cartridge having a printhead having the above-described configuration and an ink tank holding ink to be supplied to the printhead.

Further, it is preferable that the apparatus further comprises a notifying means for notifying a user of the state of the electrical connection according to a result of the measurement by the measuring means. The notification means may include an LCD for displaying a message and an LED.

According to the present invention, when the recording head is mounted on the scanning means of the recording apparatus, at least the sheet resistance of the resistor of the recording head is measured from the resistance value between the second terminal and the third terminal. Further, a control signal is input from the first terminal to drive the transistor, and the total resistance of the ON resistance and the sheet resistance of the transistor is measured from the resistance between the second terminal and the third terminal. Then, according to the measurement result, at least the electrical connection between the electrical contacts of the recording apparatus and the first and third terminals of the recording head is confirmed.

In the recording head, an NMOS transistor can be used as the plurality of power transistors and a transistor having the same characteristics as the plurality of power transistors.

Further, a shift register for inputting and temporarily storing an image signal, a latch circuit for latching image data stored in the shift register, image data output from the latch circuit, And an AND circuit for calculating a logical product with the division selection signal output from the CPU.

Preferably, the plurality of resistors, the plurality of power transistors, the selection circuit, the shift register, the latch circuit, and the AND circuit are formed on the same substrate by using a CMOS process.

A plurality of first terminals are provided, and based on a plurality of control signals input from each terminal, the selection circuit generates a division selection signal for performing division selection based on the plurality of control signals. It is desirable that the transistor that outputs and measures the ON resistance value is driven by a division selection signal generated when all of the plurality of control signals are turned ON.

[0021]

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

FIG. 1 is a perspective view showing a schematic configuration of a recording apparatus having a recording head for performing recording according to an ink jet system, which is a typical embodiment of the present invention. In this embodiment, as shown in FIG. 1, the recording head 1 is included in an ink cartridge 20 integrally formed with an ink tank 7 for supplying ink to the recording head.

In FIG. 1, a recording head 1 is mounted on a carriage 2 in a posture for ejecting ink downward in the figure, and ejects ink droplets while moving the carriage 2 along a guide shaft 3 to form recording paper. An image is formed on a recording medium (not shown) as described above. The carriage 2 is moved left and right (reciprocated) via the timing belt 5 by the rotation of the carriage motor 4. The carriage 2 is provided with an engagement claw 6, which is engaged with an engagement hole 7 a of the ink tank to fix the ink tank 7 to the carriage 2.
At this time, some electrical contacts provided on the carriage 2 and electrical contacts provided on the recording head 1 are connected, and an electrical connection is established between the recording apparatus and the recording head 1.

When printing for one scan of the print head is completed, the printing operation is interrupted, the printing medium positioned on the platen 8 is conveyed by a predetermined amount by driving the feed motor 9, and then the carriage 2 is moved again by the guide shaft. While moving along 3, the image formation for the next one scan is performed.

On the right side of the apparatus main body, a recovery device 1 for performing a recovery operation for maintaining a good ink discharge state of the recording head 1 is provided.
The apparatus 10 includes a cap 11 for capping the recording head 1, a wiper 12 for wiping the ink ejection surface of the recording head 1, and a device for sucking ink from the ink ejection nozzles of the recording head 1. A suction pump (not shown) and the like are provided.

The driving force of the feed motor 9 for conveying the recording medium is transmitted to the original recording medium conveying mechanism and also to the automatic paper feeder (ASF) 13.

Further, on the side of the recovery device 10, an infrared LE
An optical unit 14 for detecting the remaining amount of ink, comprising a D (light emitting element) 15 and a phototransistor (light receiving element) 16, is provided. The light-emitting element 15 and the light-receiving element 16 are mounted so as to be arranged along the recording paper conveyance direction (the direction of arrow F). Optical unit 1
Reference numeral 4 is attached to a chassis 17 of the apparatus main body. The ink cartridge 20 is mounted on the carriage 2 and shown in FIG.
When the ink cartridge 20 moves rightward from the position shown in FIG. 7, the ink cartridge 20 comes to be located on the optical unit 14. Then, the state of the ink can be detected by the optical unit 14 from the bottom surface of the ink tank 7.

FIG. 2 is a perspective view showing the appearance of the ink cartridge 20.

The ink cartridge 20 has a plurality of ejection ports 5.
A recording head 1 having a print head 00 and an ink tank 7 holding ink to be supplied to the recording head 1 are detachably connected at a boundary K. The ink cartridge 20 is provided with an electrical contact for receiving an electrical signal from the carriage 2 when the ink cartridge 20 is mounted on the carriage 2, and the recording head 1 is driven by the electrical signal. On the other hand, a fibrous or porous ink absorber is provided inside the ink tank 7,
The ink is held by these ink absorbers.

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

FIG. 3 is a block diagram showing a configuration of a control circuit of the printing apparatus. In the figure showing the control circuit, 170
0 is an interface for inputting a recording signal, 1701 is M
A PU 1702 is a ROM for storing a control program executed by the MPU 1701, and a 1703 is a DRAM for storing various data (such as the print signal and print data supplied to the print head 1). A gate array (G.1704) controls supply of print data to the print head 1.
A. ), The interface 1700, the MPU 170
1. Data transfer control between the RAMs 1703 is also performed. 170
5, a head driver 170 for driving the recording head 1;
Reference numerals 6 and 1707 denote motor drivers for driving the feed motor 9 and the carriage motor 4, 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
The recording head 1 is driven according to the recording data sent to 705, and recording is performed.

Reference numeral 1710 denotes an LCD 1711 for displaying various messages relating to the recording operation and the state of the recording apparatus, and LEDs of various colors for notifying the recording operation and the state of the recording apparatus.
The display unit includes a lamp 1712.

FIG. 4 is a diagram showing a configuration of a driving circuit for driving a heater mounted on the same substrate of the recording head 1 and a logic circuit for controlling the driving circuit. In this example, it is assumed that the recording head 1 has 128 ink ejection ports, and a heater for heating ink is mounted in an ink flow path communicating with each of these ink ejection ports.

Referring to FIG. 4, reference numeral 301 denotes a resistor serving as a heater, 302 denotes a power transistor for energizing the resistor 301, 303 denotes an AND circuit, 304 denotes a latch circuit (Latch), and 305 denotes a shift register (S / S).
R) and 306 are block selection signals (BLK1 to BLK1) for driving the 128 heaters in a time-division manner into 16 blocks.
BLK16), a decoder (Decorder) 310
Is a detection circuit for detecting whether or not the electrical connection between the recording head and the carriage 2 is good.

In the circuit having the above configuration, the recording data (Data) is input to the shift register (S / R) 305 in synchronization with the clock signal (CLK) while the heater voltage (VH) is applied to the resistor 301. The 128-bit print data is temporarily stored in the shift register (S / R) 3.
05, a latch clock (LTCLK) is input, and the recorded data is stored in a latch circuit (Latch).
Latch to 304. The latched recording data is A
The signal is output to the ND circuit 303.

Here, the heat enable signal (HE) is input to the AND circuit 303, and the block selection signals (BLK1 to BLK16) generated based on the block enable signals (BE0 to BE3) are decoded.
When the power transistors 302 are sequentially output, eight power transistors 302 are driven, and the corresponding resistor 30
1 and the ink is ejected.

Now, the block selection signals (BLK1-BLK)
K16) is 1 in the decoder (Decorder) 306 of FIG.
.., 16 are indicated by numerals. The block selection signals (BLK1 to BLK16) are
It is generated based on four block enable signals (BE0 to BE3) input to the recording head 1.

Block selection signals (BLK1 to BLK1)
Table 1 shows the relationship between the timing when each of the signals 6) is turned "ON" and ON / OFF of the block enable signals (BE0 to BE3).

[0040]

[Table 1]

[0041] In this embodiment, these circuits are formed on the same substrate by a CMOS process, and the power transistor 3
02 is an NMOS, and the transistors constituting the logic circuit are CMOS. Here, although not shown, a protective layer is formed on the heater (resistor) 301, and a nozzle plate for forming an ink discharge port is bonded thereon. The recording head is completed by electrically connecting the plates by wire bonding or the like. Power transistor 30
Reference numeral 2 denotes a gate (G) connected to the output from the AND circuit 303, a drain (D) connected to the resistor 301, and a source (S) connected to the Vss terminal.

By the way, a driving element such as the power transistor 302 is generally a bipolar transistor or an NMO.
It is generally formed of an S transistor. Each transistor has an ON resistance value. In particular, it is said that the variation in the ON resistance value of the NMOS transistor is large.

However, the power transistor 302
Is an NMOS transistor, the entire drive circuit and logic circuit can be formed by using a CMOS process. Therefore, there is an advantage that the cost of the manufacturing process of the substrate on which the drive circuit and the logic circuit are mounted can be reduced. is there.

On the other hand, as described above, since the NMOS transistor generally has a large variation in the ON resistance value, when the power transistor 302 is an NMOS transistor,
It is expected that electric energy applied to the heater (resistor) varies. When using an ink cartridge in which an ink tank and a recording head are integrated as in this embodiment, the user replaces the ink cartridge.
The optimum driving conditions must be automatically set from the recording device according to the variation in the resistance value. Therefore, a replaceable printhead is provided with an element for detecting the characteristics of the power transistor formed on the substrate, and the drive condition of the printhead is changed based on the detection information from the element. Is available.

Specifically, a power transistor having the same design as the power transistor in the substrate is mounted on the substrate of the recording head as an element for measuring the ON resistance. And that O
The N resistance measuring element is driven from the recording device side, the ON resistance value is calculated from the relationship between the applied current and the measured voltage, and the driving condition (heat pulse width) is changed according to the value of a table preset in the recording device. Let it. By doing so, the electric energy applied to the heater (resistor) can be made constant even if the recording head is replaced. If this electric energy is constant for any recording head, a constant ink ejection performance can be obtained even if the recording head is replaced, and the recording quality becomes uniform. Also,
An overcurrent is not applied to the power transistor or the heater for a long period of time (that is, an overload occurs) and the life of the recording head is not shortened, and the reliability of the recording head itself is improved.

Further, in this embodiment, Japanese Patent Application Laid-Open
No. 6077, heater (resistor)
In order to correct the electric energy applied to the heater that fluctuates due to the variation of the sheet resistance value of the heating resistance layer that forms the heater, a terminal for detecting the variation of the sheet resistance value is provided on the substrate on which the heater is formed, The electrical energy applied to the heater is kept constant by extracting the detection information from the terminal and changing the conditions (heat pulse width) for driving the printhead from the printing apparatus.

In this embodiment, the power transistor 3
02 and information on the variation of the sheet resistance value can be obtained from one terminal. This is realized by the detection circuit 310 described below.

FIG. 5 is a circuit diagram showing a configuration of the detection circuit 310.

In FIG. 5, reference numeral 307 denotes an NM having the same design as the power transistor 302 serving as an ON resistance value measuring element.
An OS power transistor 308 is a sheet resistance measuring unit. Here, the sheet resistance has an aspect ratio of 4: 1, and the measuring unit 308 measures a sheet resistance by applying a terminal in the longitudinal direction of the sheet resistance. Therefore, in this embodiment,
While the sheet resistance in the horizontal direction is about 50Ω, the measured value in the measurement unit 308 is about 200Ω. Also, NMO
The gate length of the S power transistor 307 is 1/40 of that of the power transistor 302 which is the driving element of the actual recording head. The ON resistance value of the power transistor 302 is 6Ω, while
The power transistor 307 has a measured value of about 240Ω.

As shown in FIG. 5, an NMOS power transistor 307 and a sheet resistor 308 are connected in parallel,
The block selection signal (BLK16) is applied to the gate (G) of the NMOS power transistor 307. Accordingly, ON / OFF of the NMOS power transistor 307 is controlled by the BLK 16. With such a configuration, when BLK16 is "ON", O
N resistance measurement element (NMOS power transistor 30
When the total resistance of 7) and the measuring unit 308 for detecting the variation of the sheet resistance is “OFF”, only the information from the measuring unit 308 for detecting the variation of the sheet resistance is detected from the Rank terminal.

Next, a procedure for detecting a connection failure of the recording head with the recording apparatus in the recording apparatus and the recording head having the above-described configuration will be described with reference to a flowchart shown in FIG.

By this procedure, an important contact failure of the recording head is detected. This procedure is executed first after the recording head is mounted on the recording apparatus.

In the circuit as shown in FIG. 4, factors that may cause the heater to operate abnormally or be damaged due to a contact failure with the printing apparatus include the Vss terminal and the block enable signal terminals (BE0 to BE3). ). If the Vss terminal is not properly connected, the power transistor 302 is always turned on, and the heater may malfunction. BE0, BE1, BE2, BE
If the three terminals are not connected properly, block selection is not performed correctly, and extra electric energy is applied to the heater, which may damage the heater. On the other hand, for other terminals, the heater is not driven even if the connection is poor, or
Only an unusual ink ejection operation occurs, and there is no risk of breakage or disconnection of the heater. Therefore, in this embodiment, the Vss terminal and BE0, BE1, BE2, B
Only the connection failure of the E3 terminal is considered.

First, in step S1, the Vss terminal and R
Measure the resistance value between the ank terminals. At this time, the block selection signal BLK16 is "OFF",
Since the NMOS power transistor 307 is not driven, only the sheet resistance is measured. This measurement is 2
If it is not about 00Ω, it is considered that there is a contact failure of the Vss terminal or the Rank terminal, and the process proceeds to step S5.
On the other hand, if the measured resistance value is about 200Ω, it is determined that the sheet resistance is correctly measured, that is, both the Rank terminal and the Vss terminal are correctly electrically connected,
The process proceeds to step S2.

Next, in step S2, the logic drive voltage Vdd is applied to the decoder 306, and the block selection signal B is applied.
LK16 is turned “ON”, and the NMOS power transistor 307 is driven. As can be seen from Table 1,
Turning on the block selection signal BLK16 means that all of the block enable signals (BE0 to BE3) are "1".
(ON) "means that the BE0, BE1, BE2, and BE3 terminals are connected to a pull-down resistor. To BE3) is “OFF (0).” Therefore, if there is at least one connection failure terminal, the block selection signal BLK16 does not become “ON”.

Therefore, in step S3, the NMOS power transistor 307 is driven, and the Vss terminal is connected to the Rank.
By measuring the resistance value between the terminals, BE0,
It is checked whether the BE1, BE2, and BE3 terminals are correctly connected.

Here, if the measured resistance value is about 110Ω, the process proceeds to step S4, which is substantially equal to the ON resistance value of the NMOS power transistor 307 and the total resistance value of the sheet resistance value, so that the block selection signal BLK16 Is "ON", that is, BE0, BE1, BE
2. It is determined that the BE3 terminal is correctly connected. Thereafter, the process ends.

On the other hand, if the measured resistance value is around 200Ω or any other value, BE0, B0
It is determined that the E1, BE2, and BE3 terminals are not correctly connected, and the process proceeds to step S5. In step S5, it is determined that the value electrical connection between the printhead and the printing apparatus is not correctly made, and for example, a warning message is displayed on the LCD of the operation panel 1710, or the LE of a specific color is displayed.
The D lamp is turned on to notify the user.

Therefore, according to the above-described embodiment, when the recording head is mounted, the conditions are changed to change the Vss terminal and the Rank.
The resistance value between the Vss terminal and BE0, BE1, which can damage the heater from the measured value is measured twice.
Defective electrical contacts at the BE2 and BE3 terminals can be detected. Thereby, even when the user replaces the recording head, the connection of the electrical contacts is confirmed, so that the recording head can be prevented from being damaged.

Further, according to the embodiment described above, it is not necessary to add a special component for confirming the connection of the electric contact to the recording apparatus side, and the circuit side of the recording head as shown in FIG. There is an advantage that the production cost of the apparatus does not increase because the substrate area does not increase even if the circuit is added. Furthermore, since it is not necessary to add a special terminal for confirming the connection of the electric contact, there is an advantage that the reliability of the electric connection is not reduced for confirming the connection of the electric contact.

In the embodiment described above, the Vss terminal and BE0, B
Although attention was paid only to defective electrical contacts at the terminals E1, BE2, and BE3, the present invention is not limited to this.
For example, as shown in FIG. 6, when it is necessary to detect a connection failure of another signal system, the signal and the block selection signal BLK16
Is obtained, and the operation result is used to drive the NMOS power transistor 307.

FIG. 7 shows a configuration of a circuit for confirming an electric contact when attention is paid to a poor connection of a heat enable signal (HE) terminal. According to FIG. 7, the block selection signal BLK
AND0 and the HE signal are obtained by the AND circuit 309, and the procedure shown in FIG.
The connection failure of the HE terminal in addition to the 1, BE2 and BE3 terminals can be detected.

In the above embodiment, a means (for example, an electrothermal converter, a laser beam, or the like) for generating thermal energy as energy used for discharging ink is provided, particularly in the ink jet recording method. By using the method in which the state of the ink is changed by the thermal energy, it is possible to achieve higher density and higher definition of recording.

The typical configuration 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 an electrothermal transducer arranged corresponding to the sheet or the liquid path in which 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 respective 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 combining a plurality of recording heads as disclosed in the above-mentioned 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, and the recording head may be integrally formed or a combination of a plurality of 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 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 provided, 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.

Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copying machine, a facsimile) including one device Device).

[0075]

As described above, according to the present invention, when the recording head is mounted on the recording apparatus, the sheet resistance of the resistor of the recording head and the transistor having the same characteristics as the power transistor for energizing and driving the resistor. Has an effect that the connection failure between the recording head and the recording apparatus can be detected from the measurement result.

Further, in this measurement, it is not necessary to provide a special measurement terminal for the recording head and the recording apparatus. Therefore, the number of contacts between the recording head and the recording apparatus does not increase, and the reliability of the electrical connection is improved. Is not reduced.

Further, since only a transistor having the same characteristic as the power transistor for energizing and driving the resistor is added to the recording head, an increase in cost for detecting a connection failure between the recording head and the recording apparatus is minimized. There is also an advantage that can be.

[0078]

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a schematic configuration of a recording apparatus including a recording head that performs recording according to an inkjet method, which is a typical embodiment of the present invention.

FIG. 2 is an external perspective view of an ink cartridge having a configuration in which a recording head and an ink tank are separable.

FIG. 3 is a block diagram illustrating a configuration of a control circuit of the printing apparatus.

FIG. 4 is a diagram showing a configuration of a driving circuit for driving a heater mounted on the same substrate of the recording head 1 and a logic circuit for controlling the driving circuit.

FIG. 5 is a circuit diagram showing a configuration of a detection circuit 310.

FIG. 6 is a flowchart showing a procedure for confirming connection of an electric contact.

FIG. 7 is a diagram showing a modification of the detection circuit 310 shown in FIG.

[Explanation of symbols]

301 Resistor (Heater) 302 Power Transistor 303 AND Circuit 304 Latch Circuit (Latch) 305 Shift Register (S / R) 306 Decoder (Decorder) 307 NMOS Power Transistor (ON Resistance Measurement Element) 308 Sheet Resistance Measurement Unit 309 AND circuit 310 detection circuit

Claims (10)

[Claims] 1. A recording head for performing recording by heating ink to discharge the ink, wherein a plurality of resistors for heating the ink, and a plurality of powers for energizing and driving the plurality of resistors are provided. A transistor; a selection circuit for dividing and selecting the plurality of power transistors; a first terminal for inputting a control signal for performing division selection of the power transistor in the selection circuit; and measuring a sheet resistance value of the resistor. Resistance, a second terminal electrically connected to the sheet resistance for measuring the sheet resistance, and the same characteristics as the plurality of power transistors connected in parallel to the sheet resistance. And a third terminal to which the plurality of power transistors and one terminal of the transistor are commonly connected, The ON resistance value of the transistor is measured by the output from the second terminal, and the transistor is connected to the first terminal.
Wherein the recording head is driven based on a control signal inputted from a terminal of the recording head. 2. The recording head according to claim 1, wherein the plurality of power transistors and a transistor having the same characteristics as the plurality of power transistors are NMOS transistors. 3. A shift register for inputting and temporarily storing an image signal, a latch circuit for latching image data stored in the shift register, image data output from the latch circuit, and the selection circuit. 2. An AND circuit for calculating a logical product with a division selection signal output from the AND circuit.
3. The recording head according to 2. 4. The plurality of resistors, the plurality of power transistors, the selection circuit, the shift register, the latch circuit, and the AND circuit are formed on a same substrate using a CMOS process. The recording head according to claim 4, wherein: 5. A plurality of first terminals are provided, and based on a plurality of control signals input from each terminal, the selection circuit performs the division selection based on the plurality of control signals. The recording head according to claim 1, wherein the recording head outputs a selection signal. 6. The transistor according to claim 5, wherein the transistor whose ON resistance value is measured is driven by a division selection signal generated when all of the plurality of control signals are turned ON. Recording head. 7. A recording apparatus for performing recording using the exchangeable recording head according to any one of claims 1 to 6, wherein: a scanning unit that reciprocates the recording head; and at least the first and second scanning units. And an electrical contact for making an electrical connection with the recording head via a third terminal; and when the recording head is mounted on the scanning means, at least the sheet resistance is set to the second terminal and the third terminal. The control signal is measured from the resistance value between the terminals, and
Measuring means for driving the transistor by inputting from the terminal of the first terminal and measuring the total resistance of the ON resistance of the transistor and the sheet resistance from the resistance between the second terminal and the third terminal; A recording apparatus comprising: at least a confirmation unit that confirms an electrical connection between the electrical contact and the first and third terminals according to a measurement result by a measurement unit. 8. According to the measurement result by the measuring means,
8. The recording apparatus according to claim 7, further comprising a notification unit configured to notify a user of the state of the electrical connection. 9. The method according to claim 1, wherein said notifying means displays a message.
9. The recording apparatus according to claim 8, comprising a CD and an LED. 10. A printhead cartridge comprising: the printhead according to claim 1; and an ink tank holding ink to be supplied to the printhead.