JP2000000969A - Substrate for recording head, recording head, recording head cartridge and recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a substrate for recording head which causes no erroneous action even if the number of heaters is increased in order to perform recording at high speed. SOLUTION: A planar substrate 21 for recording head having a plurality of wiring layers is provided with a heater forming region 1, a power transistor forming region 2, and a driving logic circuit region 3. A plurality of heaters are formed in row in the heater forming region 1 and a plurality of power transistors for driving the heaters are formed in the power transistor forming region 2. A circuit for holding an image data temporarily is formed in the driving logic circuit region 3. The logic GND line 5 of the substrate 21 is formed of the first layer wiring layer and a logic power supply line 4 is formed of a second layer wiring layer through an insulation layer. The logic power supply line 4 and the logic GND line 5 are connected electrically with the circuit elements in the driving logic circuit region 3 at a plurality of points.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head substrate used for a recording head for recording on a recording medium by discharging ink in accordance with an ink jet system, a recording head having the recording head substrate, a recording head cartridge, and a recording head cartridge. It relates to a recording device.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a circuit configuration of a recording head mounted on a conventional ink jet recording apparatus. The electrothermal transducer shown in FIG. 4 and a drive circuit for driving the electrothermal transducer are disclosed in, for example, Japanese Patent Application Laid-Open No. 5-185.
As shown in Japanese Patent No. 594, it is formed on one substrate by using a semiconductor process technology.

[0003] As shown in FIG.
A plurality of heaters 101 are provided as electrothermal conversion elements. The heater 101 generates thermal energy for performing recording by discharging a liquid. Each heater 101 is electrically connected to a power transistor section 102 as a drive circuit. The power transistor section 102 drives the heater 101 by supplying a desired current to the heater 101.

[0006] The power transistor section 102 is connected to a latch circuit 103 as a holding circuit via a switch 109. The switch 109 determines the timing at which a current flows through the heater 101. The latch circuit 103 temporarily holds image data corresponding to each heater 101 for each heater 101. The latch circuit 103 has a latch signal input terminal 1
08 is electrically connected. Latch signal input terminal 1
To 08, a latch timing signal sent to the latch circuit 103 is input.

[0005] Image data indicating whether or not to eject ink from the nozzles of the recording head is temporarily stored in a shift register 104. The shift register 104 is electrically connected to the image data input terminal 106 and the transfer clock input terminal 107. Image data for turning on or off the power supply to the heater 101 is serially input to the image data input terminal 106. You.

[0006] Each heater 101 is electrically connected to a power supply line 105 for applying a predetermined voltage to the heater 101 to supply a current. The current flowing through the heater 101 and the power transistor 102 flows into the ground line 110.

The number of image data bits stored in the shift register 104, the number of power transistors 102, and the number of heaters 101 are all the same.

Next, the operation of the circuit of the recording head shown in FIG. 4 will be described with reference to FIGS. FIG.
5 is a timing chart of various signals for driving the circuit of the recording head shown in FIG.

The transfer clock (CLK) for the number of bits of the image data stored in the shift register 104 is input to the transfer clock input terminal 107. Assuming that the data transfer to the shift register 104 is performed in synchronization with the rising timing of the transfer clock (CLK), image data (DATA) for turning on or off each heater 101 is transmitted from the image data input terminal 106. Is entered.

Here, since the number of bits of the image data stored in the shift register 104 is the same as the number of the heaters 101 and the current driving power transistors, the transfer clocks (the number of the heaters 101) are equal to the number of the heaters 101. CLK) to input image data (DATA)
Is transferred to the shift register 104. After that, a latch signal (LT) is given to the latch signal input terminal 108 to cause the latch circuit 103 to hold image data corresponding to each heater 101.

When the switch 109 is turned on for an appropriate time, a current flows through the power supply line 105 to the heater 101 and the power transistor 102 according to the length of time that the switch 109 is on. Heater 101 and power transistor 102
Flows into the ground line 101. At this time, heat necessary for discharging ink is generated from the heater 101, and ink corresponding to image data is discharged from nozzles of the recording head.

FIG. 6 is a top view showing a recording head base provided in the recording head described with reference to FIGS. The shape of the recording head base provided in the recording head is rectangular as shown in FIG. A heater forming region 201 extends along one long side of one end of the long side of the recording head substrate. A plurality of heaters 10 shown in FIG.
Reference numerals 1 are formed in rows in the longitudinal direction of the recording head base. Further, a power transistor forming region 202 and a driving logic circuit region 203 are provided on the recording head substrate. A plurality of power transistor portions 102 are formed in the power transistor formation region 202, and a shift register 104,
A plurality of latch circuits 103 serving as holding circuits, a plurality of switches 109, and the like are formed.

Further, a logic power supply line 21 serving as a power supply pattern is provided on the first wiring layer of the printhead base.
3 and a logic ground (GND) line 214 serving as a ground pattern. Logic power supply line 213 and logic GND line 214
Is made of aluminum or an aluminum wiring made of an alloy containing aluminum.

Most of the logic power supply lines 213 are formed on the first wiring layer of the recording head substrate.
Logic power supply line 2
Reference numeral 13 is electrically connected from one end of the logic circuit region 203 to a circuit element in the logic circuit region 203. Most of the logic GND line 214 is also formed of Al wiring formed on the first wiring layer of the recording head substrate.
Are electrically connected to circuit elements in the logic circuit region 203 from the other end of the logic circuit region 203.

[0015]

However, in the conventional print head substrate, the logic power supply line applied to the drive circuit and the holding circuit and the logic GND line into which the current from the drive circuit and the holding circuit flows are the same. It is formed on the wiring layer. In this case, when the number of heaters is increased in order to perform high-speed printing and the printhead base is made longer, the voltage drop of the logic power supply line becomes large, or the logic power supply line and the logic GND line become large. In addition, there is a problem that switching noise is added to the circuit, and there is a possibility that the circuit of the recording head substrate malfunctions.

An object of the present invention is to provide a recording head base that does not malfunction even when the number of heaters is increased to increase the length of the recording head base for high-speed recording.
An object of the present invention is to provide a recording head, a recording head cartridge, and a recording apparatus each including the recording head base.

[0017]

To achieve the above object, the present invention provides a plurality of electrothermal transducers, a driving circuit for driving the plurality of electrothermal transducers, and a drive circuit for driving the electrothermal transducer. And a power supply pattern electrically connected to the driving circuit and the holding circuit for supplying power to the driving circuit and the holding circuit; and a power supply pattern for supplying power to the driving circuit and the holding circuit. A power supply pattern and the ground pattern are formed at a plurality of locations on a substrate for a recording head, in which a ground pattern into which a current from a circuit flows is formed on a substrate having a plurality of wiring layers. And the power supply pattern and the ground pattern are different from each other so as to overlap with each other via an insulating layer. Characterized in that it is formed in a different wiring layer.

In the above invention, the power supply pattern and the ground pattern are electrically connected to the driving circuit and the holding circuit at a plurality of locations, respectively. Therefore, even when the recording head base is made longer by increasing the number of print heads, the power supply pattern and the ground pattern can be widened, and the voltage drop of each pattern can be prevented. Further, the power supply pattern and the ground pattern are formed on different wiring layers different from each other so as to overlap with the insulating layer interposed therebetween, so that a capacitance is formed between the power supply pattern and the ground pattern. As described above, even if the number of electrothermal transducers is increased to perform high-speed recording and the printhead base is made longer, the switching noise generated when the electrothermal transducers are driven is absorbed, and Voltage fluctuations of the pattern and the ground pattern are suppressed. As a result, malfunction of the circuit of the recording head substrate is prevented, and a highly reliable recording head substrate is obtained.

It is preferable that the electrothermal conversion element generates heat energy for performing recording by discharging a liquid, and the drive circuit is configured using a power transistor.

[0020]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a top view showing a recording head substrate according to a first embodiment of the present invention.
A multi-layer wiring technique is used for the recording head substrate of the present embodiment. As described later, metal wiring for electrically connecting circuit elements formed on the recording head substrate is formed by multi-layer wiring in the recording head substrate. It has a structure. Each wiring layer is electrically connected through a through hole formed at a predetermined location on the recording head base. Aluminum or an alloy containing aluminum is used as the material of the metal wiring formed on the recording head base.

As shown in FIG. 1, the shape of the recording head base 21 of this embodiment is rectangular. At one end of the long side of the recording head base 21, the heater forming region 1 extends along one long side. In the heater forming area 1, a plurality of heaters as electrothermal transducers are arranged in a direction parallel to the long side of the recording head base 21. The heater formed in the heater formation region 1 generates thermal energy for performing recording by discharging a liquid.

The recording head substrate 21 is provided with a power transistor forming region 2 and a driving logic circuit region 3 extending in the longitudinal direction of the recording head substrate 21. In the power transistor formation region 2, a plurality of power transistors for driving the heater in the heater formation region 1 are formed, and in the drive logic circuit region 3,
Although not shown in FIG. 1, a shift register, a latch circuit as a holding circuit, and a switch are formed in the same manner as in a conventional printhead base. A drive circuit is configured using the switches in the drive logic circuit area 3 and the power transistors in the drive logic circuit area 3.

The shift register temporarily stores, as image data, an image signal input with the number of bits corresponding to the number of heaters in the heater forming area 1. The latch circuit latches the image signal stored in the shift register and temporarily holds the image signal as image data. The recording head base 21 is provided with an input terminal for inputting an image signal and an input terminal for inputting a latch signal.

The recording head base 21 has a logic power supply as a power supply pattern formed of a conductor at a portion or a predetermined position between the driving logic circuit area 3 and the other long side of the recording head base 21. Line 4 is formed. The logic power supply line 4 is electrically connected to the latch circuit, the shift register, and the switch in the driving logic circuit area 3 at a plurality of locations.

Here, the logic power supply line 4 is a second wiring layer, and the logic ground (GND) line 5 as a ground pattern is a first wiring layer. Therefore, the logic power supply line 4 and the logic GND line 5 are formed in different wiring layers different from each other. Here, the logic power supply line 4 and the logic GND line 5 are formed so as to overlap with an insulating layer interposed therebetween, and the logic power supply line 4 and the logic GND line 5 are electrically insulated. The logic GND line 5 includes a driving logic circuit area 3
Current flows from the latch circuit and the shift register.

The material of the logic power supply line 4 and the logic GND line 5 is aluminum or
An alloy containing aluminum is used.

In the portion between the driving logic circuit region 3 and the other long side of the recording head substrate 21, a bonding pad 6 for logic power supply and a logic GND are provided.
Bonding pad 7 is formed. The logic power supply bonding pad 6 is electrically connected to the logic power supply line 4, and the logic GND bonding pad 7 is electrically connected to the logic GND line 5.

Further, the recording head substrate 2 of the present embodiment
1, a through hole 8 is formed at a predetermined position. The power supply line 4 for logic is
Are electrically connected to a wiring pattern of another wiring layer different from the logic power supply line 4.

As described above, in the recording head substrate 21 of the present embodiment, the logic power supply line 4 and the logic GND line 5 are arranged so as to overlap with the insulating layer interposed therebetween. A suitable capacitance is formed between the logic GND line 4 and the GND line 5 for logic. Since the logic power supply line 4 and the logic GND line 5 are formed on different wiring layers different from each other, their wiring patterns can be connected to respective circuit elements from both sides of the driving logic circuit region 3. it can. As a result, as compared with the conventional recording head substrate, the logic power supply line and the logic GN
The D line can be widened, and the voltage drop of each wiring pattern can be prevented.

From these facts, even if the number of heaters in the heater forming area 1 is increased to perform high-speed recording and the recording head base 21 is lengthened, switching noise when the heaters are driven is absorbed. In addition, voltage fluctuations of the logic power supply line 4 and the logic GND line 5 are suppressed. As a result, malfunction of the circuit of the recording head substrate 21 is prevented, and the highly reliable recording head substrate 2
1 is obtained.

Next, a description will be given of a printhead cartridge on which a printhead having the printhead substrate 21 of the above-described embodiment is mounted.

FIG. 2 is a schematic exploded perspective view of a recording head cartridge provided with a recording head having the above-described recording head substrate 21. The recording head cartridge mainly includes a recording head 500, a liquid container 590, and a liquid container 590. It is roughly constituted from.

The recording head 500 is composed of the recording head base 2.
1. Separation wall 530, grooved top plate 550, holding spring 57
8, a liquid supply member 580, a support 570, and the like. As described above, the recording head base 21 is provided with a plurality of heaters 1 for applying heat to the liquid in a row, and a functional element for selectively driving the heater 1 is provided. A plurality is provided. By joining the recording head base 21 and the grooved top plate 550, an ejection flow path (not shown) through which the ejection liquid to be ejected flows is formed.

The pressing spring 578 is a member for applying a biasing force to the grooved top plate 550 in the direction of the recording head base 21, and this biasing force causes the recording head base 21 and the grooved top plate 550 to be described later. The support 570 and the support 570 are integrated well.

The support 570 is for supporting the recording head base 21 and the like. On the support 570, a circuit board 571 for connecting to the recording head base 21 and supplying an electric signal is further provided. A contact pad 572 for exchanging electrical signals with the device by connecting to the device is disposed.

The liquid container 509 contains a discharge liquid such as ink supplied to the recording head and holds the discharge liquid. Outside the liquid container 590, a positioning portion 594 for disposing a liquid supply member 580 for connecting the recording head to the liquid container and a fixed shaft 595 for fixing the connection portion are provided. The supply of the discharged liquid is performed through the discharged liquid supply path 592 of the liquid container 590 and the liquid supply member 58.
The liquid is supplied to the discharge liquid supply path 583 of the liquid supply member 580 through the supply path
It is supplied to the common liquid chamber via 79 and 521.

FIG. 3 is a schematic perspective view showing an example of an ink-jet recording apparatus to which the above-mentioned recording head is mounted and applicable. In FIG. 3, reference numeral 601 denotes a recording head cartridge in which the recording head 500 and the liquid container 590 in the above-described embodiment are integrated or the liquid container 590 is detachable. The recording head cartridge 601 is driven by the driving force transmission gear 6 in conjunction with the forward / reverse rotation of the driving motor 602.
Lead screw 6 rotating through 03 and 604
Carriage 607 engaging with the spiral groove 606 of FIG.
And is reciprocated in the directions of arrows a and b along the guide 608 together with the carriage 607 by the power of the drive motor 602. A paper press plate 610 for a print sheet P as a recording medium conveyed on a platen 609 by a recording medium supply device (not shown) presses the print sheet P against a platen roller 609 in the carriage movement direction.

In the vicinity of one end of the lead screw 605, photocouplers 611 and 612 are provided. These are home position detecting means for confirming the presence of the lever 607a of the carriage 607 in this area and switching the rotation direction of the drive motor 602 and the like.
In the figure, reference numeral 613 denotes a support member that supports a cap member 614 that covers the front surface of the above-described recording head having the ejection openings. Reference numeral 615 indicates the cap member 61.
4 shows an ink suction means for sucking ink accumulated by the idle discharge from the print head of the print head cartridge 601 inside the print head cartridge 601. The suction unit 615 performs suction recovery of the recording head of the recording head cartridge 601 through the opening in the cap. Reference numeral 617 denotes a cleaning blade, and reference numeral 618 denotes a moving member that enables the blade 617 to move in the front-rear direction (a direction orthogonal to the moving direction of the carriage 607). The blade 617 and the moving member 618 are body support members. 619. The blade 617 is not limited to this form,
Other well-known cleaning blades may be used. Reference numeral 620 denotes a lever for starting suction in the suction recovery operation, and the cam 62 engaged with the carriage 607.
1 and the driving force from the driving motor 602 is controlled by a known transmission means such as clutch switching. An ink jet recording control unit for giving a signal to the heating element 202 provided on the recording head of the recording head cartridge 601 and controlling the driving of each mechanism described above is provided on the apparatus main body side. Is not shown.

In the ink jet recording apparatus 600 having the above-described configuration, the recording head cartridge 601 performs recording while reciprocating over the entire width of the paper P on the printing paper P conveyed on the platen 609 by a recording medium supply device (not shown). Do.

[0041]

As described above, according to the present invention, each of the driving circuit and the holding circuit is electrically connected to each of the power supply pattern and the ground pattern, and the power supply pattern and the ground pattern overlap via the insulating layer. Thus, even when the number of electrothermal transducers is increased to perform high-speed recording and the printhead base is made longer by forming them on different wiring layers different from each other, the voltage of the power supply pattern and the ground pattern is increased. This has the effect of suppressing fluctuations and preventing erroneous operation of the circuit of the printhead base.

[Brief description of the drawings]

FIG. 1 is a top view showing a printhead base according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a recording head cartridge provided with a recording head having the recording head substrate shown in FIG.

FIG. 3 is a schematic perspective view showing an example of an inkjet recording apparatus to which the recording head shown in FIG. 2 can be attached and applied.

FIG. 4 is a diagram illustrating a configuration of a circuit of a recording head mounted on a conventional inkjet recording apparatus.

5 is a timing chart of various signals for driving the circuit of the recording head shown in FIG.

FIG. 6 is a top view showing a printhead base provided in the printhead described with reference to FIGS. 4 and 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater formation area 2 Power transistor formation area 3 Drive logic circuit area 4 Logic power supply line 5 Logic GND line 6 Logic power supply bonding pad 7 Logic GND bonding pad 8 Through hole 21 Recording head base 500 Recording head 521 Ejection Liquid supply path 530 Separation wall 550 Top plate with groove 570 Support 571 Circuit board 572 Contact pad 578 Pressing spring 579 Discharge liquid supply path 580 Liquid supply member 581 Supply path 583 Discharge liquid supply path 590 Liquid container 592 Discharge liquid supply path 594 Positioning Unit 595 Fixed shaft 600 Inkjet recording device 601 Recording head cartridge 602 Driving motor 603, 604 Driving force transmission gear 605 Lead screw 606 Spiral groove 607 Carry Di 607a lever 608 guide 609 platen 610 paper pressing plate 611, 612 photocoupler 613 supporting member 614 cap member 615 ink suction means 617 cleaning blade 618 moves member 619 main support 620 lever 621 cams P print paper

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tomoyuki Hiroki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiko Ogawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon In-house F-term (reference) 2C057 AF35 AF71 AG46 AG84 AG92 AG94 BA13

Claims (6)

[Claims] A plurality of electrothermal transducers; a driving circuit for driving the plurality of electrothermal transducers; a holding circuit for holding image data for driving the electrothermal transducers; A power supply pattern that is electrically connected to the holding circuit and supplies power to the driving circuit and the holding circuit, and a ground pattern into which current from the driving circuit and the holding circuit flows, form a plurality of wiring layers. Wherein the power supply pattern and the ground pattern are electrically connected to the drive circuit and the holding circuit at a plurality of locations, respectively, and the power supply pattern and the ground are provided. The pattern is formed on different wiring layers different from each other so as to overlap with each other via an insulating layer. De for the substrate. 2. The recording head substrate according to claim 1, wherein the electrothermal conversion element generates thermal energy for performing recording by discharging a liquid. 3. The printhead base according to claim 1, wherein the drive circuit is configured using a power transistor. 4. A recording medium comprising a substrate for a recording head according to claim 1, wherein the recording medium is driven by driving the electrothermal transducers of the recording head substrate to discharge a liquid. A recording head that performs recording. 5. A recording head cartridge comprising: the recording head according to claim 4; and a liquid container for holding a liquid supplied to the recording head. 6. A recording apparatus comprising: the recording head according to claim 4; and a recording medium supply device that conveys a recording medium that receives a liquid discharged from the recording head.