The present disclosure generally relates to a recording element substrate, a liquid ejection head, and a liquid ejection apparatus.
In a liquid ejection apparatus, energy generating elements provided on a recording element substrate of a liquid ejection head are driven using a driving power supply and a control signal, and liquid is thereby ejected from ejection ports. The recording element substrate is provided with contact pads that receive a power supply and a control signal from the main body of the liquid ejection apparatus, and conductors that transmit the power supply and the control signal.
In such a liquid ejection apparatus, a plurality of energy generating elements are driven at the same time for high-speed recording. When a plurality of energy generating elements are driven at the same time, the current flowing through the conductors changes depending on the number of energy generating elements being driven at the same time, which changes the voltage applied to the energy generating elements. As a result, the amount and velocity of ejected liquid changes, and the quality of the recorded image may deteriorate.
In order to suppress the change of voltage applied to energy generating elements, it is possible to provide a different conductor for each of the plurality of energy generating elements driven at the same time. However, providing a different conductor for each energy generating element throughout the route from contact pads to energy generating elements is difficult because it causes an increase in the substrate area. For this reason, Japanese Patent Laid-Open No. 10-44416 discloses a recording element substrate having a conductor that is shared by a plurality of energy generating elements in the vicinity of a contact pad and that branches toward the energy generating elements.
However, in the configuration disclosed in Japanese Patent Laid-Open No. 10-44416, a supply port that is common to and supplies liquid to a plurality of energy generating elements arranged on the same straight line is provided in a rectangular shape that opens continuously. However this causes the substrate area to increase significantly with an increase in the number of energy generating elements driven at the same time. A row formed by a plurality of energy generating elements arranged on the same straight line will hereinafter be referred to as an element row.
As shown in
In order to avoid the increase in the substrate area, it is possible to reduce the width of the conductors. However, in this case, the wiring resistance increases, and the power efficiency when driving the energy generating elements decreases.
Accordingly, the present disclosure provides a recording element substrate in which the decrease in the power efficiency when driving energy generating elements can be suppressed while avoiding the increase in the substrate area accompanying the increase in the number of energy generating elements driven at the same time.
In an aspect of the present invention, a recording element substrate includes a substrate, a plurality of energy generating elements arranged on the substrate to form an element row, a plurality of supply ports, supplying liquid to the energy generating elements, arranged along the element row to form a supply port row, and a plurality of supply paths extending from the plurality of supply ports along the thickness direction of the substrate, wherein a plurality of beam portions disposed between adjacent supply ports in the direction of the supply port row has a plurality of conductor layers in which a conductor layer including a power supply conductor connected to the energy generating elements and a conductor layer including a ground conductor connected to the energy generating elements, are stacked along the thickness direction of the substrate, and wherein at least one of the plurality of conductor layers is occupied by one power supply conductor or one ground conductor.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Embodiments of the present disclosure will now be described with reference to the drawings. In this specification and drawings, components having the same function are given the same reference numerals, and redundant description thereof may be omitted.
The recording element substrate 100 has a substrate 101, energy generating elements 102, individual supply paths 103, power supply conductors 104a, ground conductors 104b, electrode pads 105, and common supply paths 107.
The energy generating elements 102 are elements that generate energy for ejecting liquid. The energy generating elements 102 may be any of various types of elements proposed in liquid ejection technology, and are, for example, elements that convert electric energy into heat energy or mechanical energy. The plurality of energy generating elements 102 are arranged linearly on the substrate 101, and form element rows 102a and 102b.
The individual supply paths 103 are flow paths that are provided in correspondence to the energy generating elements 102 and that supply liquid to the corresponding energy generating elements 102. The individual supply paths 103 are flow paths extending along the thickness direction of the substrate 101, and communicate with the common supply paths 107. On a surface of the substrate 101 on which the energy generating elements 102 are provided, supply ports that are openings of the individual supply paths 103 are arranged on straight lines substantially parallel to the element rows 102a, and form supply port rows 103a. In other words, the individual supply paths 103 are flow paths that extend from the supply ports along the thickness direction of the substrate 101. In the example of
The power supply conductor 104a and the ground conductor 104b are connected to the energy generating elements 102 and the electrode pads 105 and supply a signal to the electrode pads 105 and to the energy generating elements 102. The power supply wiring and the ground wiring are multilayer structures in which a plurality of conductor layers are stacked along the thickness direction of the substrate 101. In
The electrode pads 105 are contact portions that receive a power supply and a control signal from the outside. In the example of
As shown in
The width L1 of the beam portions 106 has a trade-off relationship with the flow path width L2 of the individual supply paths 103. That is, if the flow path width L2 of the individual supply path 103 is reduced, the width L1 of the beam portions 106 can be increased, and therefore, the width of conductors provided in the beam portions 106 can be increased. However, if the flow path width L2 of the individual supply paths 103 is too small, it is difficult to supply liquid to the energy generating elements 102 efficiently. Because the individual supply paths 103 are formed, for example, by dry etching so as to penetrate from one surface of the substrate 101 to the other surface, if the flow path width L2 of the individual supply paths 103 is too small, a problem of workability arises. For this reason, the flow path width L2 of the individual supply paths 103 is preferably greater than or equal to a certain value. Since there is a lower limit to the flow path width L2 of the individual supply paths 103, it is difficult to increase the width L1 of the beam portions 106 when the length of the substrate 101 in the direction of the element rows 102a is fixed. When providing conductors in the beam portions 106, it is preferable to provide certain intervals between the conductors and the individual supply paths 103 taking into consideration of the working accuracy of the individual supply paths 103 and the conductors. If the width L1 of the beam portions 106 and the distance between the conductors passing through the beam portions 106 and the individual supply paths 103 are taken into consideration, the width of the conductors passing through the beam portions 106 decreases, and the wiring resistance thereof increases.
So, in this embodiment, at least one of the plurality of conductor layers of the beam portions 106 is occupied by one power supply conductor 104a or one ground conductor 104b.
In the example shown in
In the first embodiment of the present disclosure, a supply port row 103a is formed in correspondence to a plurality of element rows 102a and 102b. The supply port row 103a includes a plurality of supply ports that are openings of the individual supply paths 103. For this reason, beam portions 106 that are regions sandwiched between adjacent supply ports are formed on the substrate 101. Owing to the presence of the beam portions 106, conductors connecting different element rows 102a and 102b can be provided, and it is not necessary to provide different conductors in correspondence to different element rows 102a and 102b. That is, energy generating elements 102 of different element rows 102a and 102b can be connected to a common power supply conductor 104a and a common ground conductor 104b provided in a part other than the beam portions 106, through power supply conductors 104a and ground conductors 104b passing through the beam portions 106.
In the beam portions 106, in order to reduce the conductor resistance, in this embodiment, the conductor layers are stacked in a multilayer structure. At least one of the plurality of conductor layers of the beam portions 106 is occupied by one power supply conductor 104a or one ground conductor 104b. If more than one conductor is provided in a conductor layer, the conductors are disposed at intervals, and therefore the width of the conductors provided in the beam portions 106 decreases correspondingly and resistance increases. Therefore, at least one of the plurality of conductor layers forming the beam portions 106 is occupied by one conductor, so that the resistance of the conductors passing through the beam portions 106 can be reduced, and if a plurality of energy generating elements 102 are driven at the same time, the effect of voltage drop in the conductors can be suppressed. When a conductor layer is occupied by one conductor, the width of the conductor is preferably one-half or more of the width L1 of the beam portions 106. In order to further suppress the effect of voltage drop, the beam portions 106 preferably have a conductor layer occupied by a power supply conductor 104a and a conductor layer occupied by a ground conductor 104b.
A liquid ejection head having a plurality of recording element substrates 100 arranged in the direction of element rows 102 can also be formed. A liquid ejection apparatus that has a liquid ejection head and that drives energy generating elements 102 and ejects liquid can also be formed.
The difference from the first embodiment will be mainly described. In the first embodiment, one individual supply path 103 is provided for two energy generating elements 102, whereas in the second embodiment, one individual supply path 103 is provided for four energy generating elements on both sides. Therefore, in this embodiment, the number of individual supply paths 103 included in one supply port row 103a is half of that in the first embodiment. The interval between adjacent energy generating elements 102 included in the element rows 102a is less than the interval between adjacent individual supply paths 103 included in the supply port row 103a provided in correspondence to the element rows 102a.
By virtue of such a configuration, although the number of beam portions 106 sandwiched between adjacent individual supply paths 103 is small, the width of the beam portions 106 can be increased. Therefore, the width of the conductors passing through the beam portions 106 can be increased, and the resistance of the conductors passing through the beam portions 106 can be further reduced. The configuration of the multilayer conductors provided in the beam portions 106 is the same as that described in the first embodiment, and it is preferable to make the width of the conductors as large as possible in accordance with the increase in the width of the beam portions 106.
By virtue of such a configuration, a liquid circulation path leading from the individual supply paths 103 via the energy generating elements 102 to the individual discharge paths 108 can be formed. By circulating the liquid, water in the liquid, in the vicinity of the energy generating elements 102, can be prevented from evaporating, and the viscosity of the liquid can be prevented from increasing. The recording element substrate 300 has pressure chambers that have therein energy generating elements 102 that generate energy used for ejecting liquid. A liquid ejection head having this recording element substrate 300 is configured to circulate liquid between the inside of the pressure chambers and the outside of the pressure chambers.
In such a circulation configuration, the number of flow paths provided for the element row 102a is large, and therefore the number of the beam portions 106 is also large. Therefore, the effect of conductor resistance in the beam portions 106 is significant. For this reason, conductors provided in the beam portions 106 are disposed in multiple layers as in the first embodiment. The conductor layers are occupied by a power supply conductor 104a or a ground conductor 104b, and conductor resistance can thereby be suppressed.
Also in this recording element substrate 400, all of the electrode pads 105 are provided along one side that is parallel to the element rows 102a. Therefore, when disposing a plurality of recording element substrates 400, adjacent recording element substrates 400 can be disposed close to each other. In the recording element substrate 900 of comparative example shown in
Although the present disclosure has been described with reference to embodiments, the present disclosure is not limited to the above embodiments. Various changes that can be understood by those skilled in the art may be made to the configuration or details of the present disclosure within the scope of the present disclosure.
For example, although, in the third and fourth embodiments, individual supply paths 103 and individual discharge paths 108 are provided on both sides of energy generating elements 102, and a liquid circulating path is thereby formed, the present disclosure is not limited to such an example. Individual supply paths 103 may be disposed on both sides of the energy generating elements 102, and liquid may be supplied from both sides of the energy generating elements 102.
For example, although, in the above fourth embodiment, a parallelogram substrate 401 is taken as an example of a substrate 401 whose adjacent sides are not at right angles to each other, the present disclosure is not limited to such an example. For example, the substrate 401 may be trapezoid in shape.
The numbers of energy generating elements 102 shown in the above embodiments are illustrative only, and various changes may be made according to design conditions.
For example, although, in each of the above embodiments, the configuration of a recording element substrate has been described, the present disclosure can also be mounted as a liquid ejection head having these recording element substrates or a liquid ejection apparatus having this liquid ejection head. A liquid ejection head having a plurality of recording element substrates described here preferably has a plurality of recording element substrates arranged on a straight line in a direction in which the element rows 102a extend. In this case, the plurality of recording element substrates can be disposed close to each other.
As described above, according to the present disclosure, it is possible to suppress the decrease in the power efficiency when driving energy generating elements while suppressing the increase in the substrate area accompanying the increase in the number of energy generating elements driven at the same time.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
Number | Date | Country | Kind |
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2016-107440 | May 2016 | JP | national |
This application is a continuation, and claims the benefit, of U.S. patent application Ser. No. 15/601,848, presently pending and filed on May 22, 2017, and claims the benefit of, and priority to, Japanese Patent Application No. 2016-107440 filed May 30, 2016, which applications are hereby incorporated by reference herein in their entireties.
Number | Date | Country | |
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Parent | 15601848 | May 2017 | US |
Child | 16138638 | US |