Patents by Inventor Toshifumi Asakawa
Toshifumi Asakawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6677214Abstract: In order to easily and accurately manufacture a micromachine comprising a member which is made of a single-crystalline material and having a complicated structure, an uppermost layer (1104) of a single-crystalline Si substrate (1102) whose (100) plane is upwardly directed is irradiated with Ne atom currents from a plurality of prescribed directions, so that the crystal orientation of the uppermost layer (1104) is converted to such orientation that the (111) plane is upwardly directed. A masking member (106) is employed as a shielding member to anisotropically etch the substrate (1102) from its bottom surface, thereby forming a V-shaped groove (1112). At this time, the uppermost layer (1104) serves as an etching stopper. Thus, it is possible to easily manufacture a micromachine having a single-crystalline diaphragm having a uniform thickness. A micromachine having a complicated member such as a diagram which is made of a single-crystalline material can be easily manufactured through no junction.Type: GrantFiled: June 12, 2000Date of Patent: January 13, 2004Assignees: Mega Chips Corporation, Crystal Device CorporationInventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
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Patent number: 6225668Abstract: In order to easily and accurately manufacture a micromachine comprising a member which is made of a single-crystalline material and having a complicated structure, an uppermost layer (1104) of a single-crystalline Si substrate (1102) whose (100) plane is upwardly directed is irradiated with Ne atom currents from a plurality of prescribed directions, so that the crystal orientation of the uppermost layer (1104) is converted to such orientation that the (111) plane is upwardly directed. A masking member (106) is employed as a shielding member to anisotropically etch the substrate (1102) from its bottom surface, thereby forming a V-shaped groove (1112). At this time, the uppermost layer (1104) serves as an etching stopper. Thus, it is possible to easily manufacture a micromachine having a single-crystalline diaphragm having a uniform thickness. A micromachine having a complicated member such as a diagram which is made of a single-crystalline material can be easily manufactured through no junction.Type: GrantFiled: August 25, 1997Date of Patent: May 1, 2001Assignees: Mega Chips Corporation, Silicon Technology CorporationInventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
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Patent number: 6177706Abstract: In order to easily and accurately manufacture a micromachine comprising a member which is made of a single-crystalline material and having a complicated structure, an uppermost layer (1104) of a single-crystalline Si substrate (1102) whose (100) plane is upwardly directed is irradiated with Ne atoms currents from a plurality of prescribed directions, so that the crystal orientation of the uppermost layer (1104) is converted to such orientation that the (111) plane is upwardly directed. A masking member (106) is employed as a shielding member to anistropically etch the substrate (1102) from its bottom surface, thereby forming a V-shaped groove (1112). At this time, the uppermost layer (1104) serves as an etching stopper. Thus, it is possible to easily manufacture a micromachine having a single-crystalline diaphragm having a uniform thickness. A micromachine having a complicated member such as a diagram which is made of a single-crystalline material can be easily manufactured through no junction.Type: GrantFiled: August 27, 1997Date of Patent: January 23, 2001Assignees: Mega Chips Corporation, Crystal Device CorporationInventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
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Patent number: 6137120Abstract: In order to easily and accurately manufacture a micromachine comprising a member which is made of a single-crystalline material and having a complicated structure, an uppermost layer (1104) of a single-crystalline Si substrate (1102) whose (100) plane is upwardly directed is irradiated with Ne atom currents from a plurality of prescribed directions, so that the crystal orientation of the uppermost layer (1104) is converted to such orientation that the (111) plane is upwardly directed. A masking member (106) is employed as a shielding member to anisotropically etch the substrate (1102) from its bottom surface, thereby forming a V-shaped groove (1112). At this time, the uppermost layer (1104) serves as an etching stopper. Thus, it is possible to easily manufacture a micromachine having a single-crystalline diaphragm having a uniform thickness. A micromachine having a complicated member such as a diagram which is made of a single-crystalline material can be easily manufactured through no junction.Type: GrantFiled: August 27, 1997Date of Patent: October 24, 2000Assignees: Mega Chips Corporation, Crystal Device CorporationInventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
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Patent number: 6106734Abstract: In order to easily and accurately manufacture a micromachine comprising a member which is made of a single-crystalline material and having a complicated structure, an uppermost layer (1104) of a single-crystalline Si substrate (1102) whose (100) plane is upwardly directed is irradiated with Ne atom currents from a plurality of prescribed directions, so that the crystal orientation of the uppermost layer (1104) is converted to such orientation that the (111) plane is upwardly directed. A masking member (106) is employed as a shielding member to anisotropically etch the substrate (1102) from its bottom surface, thereby forming a V-shaped groove (1112). At this time, the uppermost layer (1104) serves as an etching stopper. Thus, it is possible to easily manufacture a micromachine having a single-crystalline diaphragm having a uniform thickness. A micromachine having a complicated member such as a diaphragm which is made of a single-crystalline material can be easily manufactured through no junction.Type: GrantFiled: August 25, 1997Date of Patent: August 22, 2000Assignees: Mega Chips Corporation, Crystal Device CorporationInventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
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Patent number: 6032611Abstract: In order to form a single-crystalline thin film on a polycrystalline substrate using plasma CVD, a downwardly directed mainly neutral Ne atom current is formed by an ECR ion generator (2). A reaction gas such as silane gas which is supplied from a reaction gas inlet pipe (13) is sprayed onto an SiO.sub.2 substrate (11) by an action of the Ne atom current, so that an amorphous Si thin film is grown on the substrate (11) by a plasma CVD reaction. At the same time, a part of the Ne atom current having high directivity is directly incident upon the substrate (11), while another part thereof is incident upon the substrate (11) after its course is bent by a reflector (12). The reflector (12) is so set that all directions of the parts of the Ne atom current which are incident upon the substrate (11) are perpendicular to densest planes of single-crystalline Si.Type: GrantFiled: March 19, 1997Date of Patent: March 7, 2000Assignees: Neuralsystems Corporation, Mega Chips CorporationInventors: Toshifumi Asakawa, Masahiro Shindo, Toshikazu Yoshimizu, Sumiyoshi Ueyama
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Patent number: 6025252Abstract: In order to easily and accurately manufacture a micromachine comprising a member which is made of a single-crystalline material and having a complicated structure, an uppermost layer (1104) of a single-crystalline Si substrate (1102) whose (100) plane is upwardly directed is irradiated with Ne atom currents from a plurality of prescribed directions, so that the crystal orientation of the uppermost layer (1104) is converted to such orientation that the (111) plane is upwardly directed. A masking member (106) is employed as a shielding member to anisotropically etch the substrate (1102) from its bottom surface, thereby forming a V-shaped groove (1112). At this time, the uppermost layer (1104) serves as an etching stopper. Thus, it is possible to easily manufacture a micromachine having a single-crystalline diaphragm having a uniform thickness. A micromachine having a complicated member such as a diagram which is made of a single-crystalline material can be easily manufactured through no junction.Type: GrantFiled: August 25, 1997Date of Patent: February 15, 2000Assignee: Mega Chips CorporationInventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
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Patent number: 5993538Abstract: In order to form a single-crystalline thin film on a polycrystalline substrate using plasma CVD, a downwardly directed mainly neutral Ne atom current is formed by an ECR ion generator (2). A reaction gas such as silane gas which is supplied from a reaction gas inlet pipe (13) is sprayed onto an SiO.sub.2 substrate (11) by an action of the Ne atom current, so that an amorphous Si thin film is grown on the substrate (11) by a plasma CVD reaction. At the same time, a part of the Ne atom current having high directivity is directly incident upon the substrate (11), while another part thereof is incident upon the substrate (11) after its course is bent by a reflector (12). The reflector (12) is so set that all directions of the parts of the Ne atom current which are incident upon the substrate (11) are perpendicular to densest planes of single-crystalline Si.Type: GrantFiled: February 13, 1996Date of Patent: November 30, 1999Assignee: Mega Chips CorporationInventors: Toshifumi Asakawa, Masahiro Shindo, Toshikazu Yoshimizu, Sumiyoshi Ueyama
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Patent number: 5814150Abstract: In order to form a single-crystalline thin film on a polycrystalline substrate using plasma CVD, a downwardly directed mainly neutral Ne atom current is formed by an ECR ion generator (2). A reaction gas such as silane gas which is supplied from a reaction gas inlet pipe (13) is sprayed onto an SiO.sub.2 substrate (11) by an action of the Ne atom current, so that an amorphous Si thin film is grown on the substrate (11) by a plasma CVD reaction. At the same time, a part of the Ne atom current having high directivity is directly incident upon the substrate (11), while another part thereof is incident upon the substrate (11) after its course is bent by a reflector (12). The reflector (12) is so set that all directions of the parts of the Ne atom current which are incident upon the substrate (11) are perpendicular to densest planes of single-crystalline Si.Type: GrantFiled: February 7, 1996Date of Patent: September 29, 1998Assignees: Neuralsystems Corporation, Mega Chips CorporationInventors: Toshifumi Asakawa, Masahiro Shindo, Toshikazu Yoshimizu, Sumiyoshi Ueyama
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Patent number: 5795385Abstract: In order to form a single-crystalline thin film on a polycrystalline substrate using plasma CVD, a downwardly directed mainly neutral Ne atom current is formed by an ECR ion generator (2). A reaction gas such as silane gas which is supplied from a reaction gas inlet pipe (13) is sprayed onto an SiO.sub.2 substrate (11) by an action of the Ne atom current, so that an amorphous Si thin film is grown on the substrate (11) by a plasma CVD reaction. At the same time, a part of the Ne atom current having high directivity is directly incident upon the substrate (11), while another part thereof is incident upon the substrate (11) after its course is bent by a reflector (12). The reflector (12) is so set that all directions of the parts of the Ne atom current which are incident upon the substrate (11) are perpendicular to densest planes of single-crystalline Si.Type: GrantFiled: March 18, 1997Date of Patent: August 18, 1998Assignees: Neuralsystems Corporation, Mega Chips CorporationInventors: Toshifumi Asakawa, Masahiro Shindo, Toshikazu Yoshimizu, Sumiyoshi Ueyama
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Patent number: 5776253Abstract: In order to form a single-crystalline thin film on a polycrystalline substrate using plasma CVD, a downwardly directed mainly neutral Ne atom current is formed by an ECR ion generator (2). A reaction gas such as silane gas which is supplied from a reaction gas inlet pipe (13) is sprayed onto an SiO.sub.2 substrate (11) by an action of the Ne atom current, so that an amorphous Si thin film is grown on the substrate (11) by a plasma CVD reaction. At the same time, a part of the Ne atom current having high directivity is directly incident upon the substrate (11), while another part thereof is incident upon the substrate (11) after its course is bent by a reflector (12). The reflector (12) is so set that all directions of the parts of the Ne atom current which are incident upon the substrate (11) are perpendicular to densest planes of single-crystalline Si.Type: GrantFiled: March 19, 1997Date of Patent: July 7, 1998Assignees: Neuralsystems Corporation, Mega Chips CorporationInventors: Toshifumi Asakawa, Masahiro Shindo, Toshikazu Yoshimizu, Sumiyoshi Ueyama
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Patent number: 5748530Abstract: In a non-volatile semiconductor memory device composed of flating gate type memory cells, after the drain or source is charged, it is placed in an electrically floating state and a signal with alternately changing positive and negative potentials is applied to the control gates of the memory cells so as to reduce the charges stored in the floating gates, thereby converging the threshold volatages of the memory cells into a predetermined voltage. Thus, a write/erase operation in the memory device can be carriied out surely in a short time.Type: GrantFiled: December 20, 1994Date of Patent: May 5, 1998Assignee: NKK CorporationInventors: Hiroshi Gotou, Toshifumi Asakawa
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Patent number: 5738731Abstract: A solar cell comprising:a first junction part having a first conductivity type first semiconductor film and a second conductivity type second semiconductor film formed on an upper surface of said first semiconductor film; anda second junction part having a first conductivity type third semiconductor film formed on an upper surface of said second semiconductor film and a second conductivity type fourth semiconductor formed on an upper surface of said third semiconductor film,said junction parts arranged from that having a larger forbidden band width along the direction of progress of light through said semiconductor layers,said first, second, third, and fourth semiconductor films being formed of single-crystalline filming;wherein an interlayer conductor prepared from a metal forming ohmic junctions with each of said junction parts and having a thickness capable of transmitting light therethrough is interposed between said first and second junction parts; andwherein said second semiconductor film arranged on onType: GrantFiled: August 31, 1994Date of Patent: April 14, 1998Assignees: Mega Chips Corporation, Crystal Device CorporationInventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
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Patent number: 5729494Abstract: In a non-volatile semiconductor memory device composed of flating gate type memory cells, after the drain or source is charged, it is placed in an electrically floating state and a signal with alternately changing positive and negative potentials is applied to the control gates of the memory cells so as to reduce the charges stored in the floating gates, thereby converging the threshold voltages of the memory cells into a predetermined voltage. Thus, a write/erase operation in the memory device can be carried out surely in a short time.Type: GrantFiled: September 19, 1996Date of Patent: March 17, 1998Assignee: NKK CorporationInventors: Hiroshi Gotou, Toshifumi Asakawa
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Patent number: 5623444Abstract: The drain of a memory cell transistor is connected to a sub bit line of an EEPROM. The sub bit line is connected to a main bit line via the drain-source path of a selection transistor. The equivalent capacitance of the sub bit line is precharged to the potential of the main bit line when the selection transistor is temporarily turned on. The potential of the precharged sub bit line tends to drop in the presence of a leakage current component equivalent resistance. However, when the selection transistor is intermittently turned on by using pulses to supply charges from the main bit line to the sub bit line, a drop in sub bit line potential can be prevented.Type: GrantFiled: August 18, 1995Date of Patent: April 22, 1997Inventors: Hiroshi Gotou, Toshifumi Asakawa
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Patent number: 5565697Abstract: A semiconductor substrate comprises a foundation, a semiconductor monocrystalline film formed on the foundation, and a high-melting-point metal film or a high-melting-point metal alloy film disposed in at least part of a region between the semiconductor monocrystalline film and the foundation. The high-melting-point metal film disposed below the semiconductor monocrystalline film can be utilized as a conductor in a semiconductor device.Type: GrantFiled: June 2, 1995Date of Patent: October 15, 1996Assignee: Ricoh Company, Ltd.Inventors: Toshifumi Asakawa, Daisuke Kosaka, Haruo Nakayama
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Patent number: 5459346Abstract: A semiconductor substrate comprises a foundation, a semiconductor monocrystalline film formed on the foundation, and a high-melting-point metal film or a high-melting-point metal alloy film disposed in at least part of a region between the semiconductor monocrystalline film and the foundation. The high-melting-point metal film disposed below the semiconductor monocrystalline film can be utilized as a conductor in a semiconductor device.Type: GrantFiled: November 17, 1994Date of Patent: October 17, 1995Assignee: Ricoh Co., Ltd.Inventors: Toshifumi Asakawa, Daisuke Kosaka, Haruo Nakayama
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Patent number: 5173446Abstract: A semiconductor substrate comprises a foundation, a semiconductor monocrystalline film formed on the foundation, and a high-melting-point metal film or a high-melting-point metal alloy film disposed in at least part of a region between the semiconductor monocrystalline film and the foundation. The high-melting-point metal film disposed below the semiconductor monocrystalline film can be utilized as a conductor in a semiconductor device.Type: GrantFiled: June 13, 1991Date of Patent: December 22, 1992Assignee: Ricoh Company, Ltd.Inventors: Toshifumi Asakawa, Daisuke Kosaka, Haruo Nakayama
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Patent number: 5008554Abstract: An optical signal processing apparatus includes a plurality of plates disposed in parallel at spatial intervals and light LSIs mounted on each of the plates. The transfer of signals in the direction parallel to the surfaces of the plates is performed by lead wires electrically interconnecting the light LSIs. The transfer of signals in the direction normal to the surfaces is performed by the light emitted and received by the light LSIs.Type: GrantFiled: June 29, 1989Date of Patent: April 16, 1991Assignee: Ricoh Company, Ltd.Inventors: Toshifumi Asakawa, Haruo Nakayama
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Patent number: 4250526Abstract: A light source capable of producing intermittent flashes of light is used as a light source for illuminating an original. The light source is triggered in response to the read signal and a self-scanning type array of light receptors accumulates the charge representative of a light image focused thereon. In synchronism with the triggering of the light source, the video output is derived from memory means which stores the charge thus accumulated.Type: GrantFiled: May 23, 1979Date of Patent: February 10, 1981Assignee: Ricoh Company, Ltd.Inventors: Jyoichi Fuwa, Toshifumi Asakawa