baber/WOPTO huggingface dataset:
Patent WO-2020153244-A1 (WO)
Title: 容量制御弁
Inventor: EJIMA Takahiro
IPC: F04B27/18
Filed: 2020-01-17
Abstract: キャップの受圧面を広く確保しつつ、溶接ビードの影響を受けない容量制御弁を提供する。　ソレノイド８０により駆動されるロッド８３の移動によりバルブハウジング１０に形成される吐出ポート１２と制御ポート１４との連通を開閉する主弁５０と、バルブハウジング１０に形成される制御流体供給室６０と吸入ポート１３との間を連通するＣＳ連通路５５と、ＣＳ連通路５５の外周に環状の弁座５２ａを有する連通路構成部材５２と該弁座５２ａに対して閉弁方向に付勢される開閉弁体６１とにより構成される開閉弁５４と、を備える容量制御弁Ｖであって、開閉弁体６１は、弁座５２ａに接離するキャップ７０と、キャップ７０の外周端部７０ｄと溶接されるベローズコア６２と、を備え、キャップ７０の外周端部７０ｄには、溶接ビードＷＢを収容する凹部７０ｅが設けられている。
Patent WO-2020153257-A1 (WO)
Inventor: ARIMOTO TADASHI
IPC: G21K1/02
Filed: 2020-01-17
Abstract: ［課題］シリコンウェハを用いた従来技術とは全く異なる手段で、高輝度で大面積化・厚層化・傾斜化が可能であり、取り扱い性や熱的安定性にも優れたタルボ用格子を提供する。 Ｘ線吸収層とＸ線透過層とが、Ｘ線の入射方向に対して略平行方向に繰り返し積層された構造を有するタルボ用格子であり、Ｘ線吸収層とＸ線透過層の少なくとも一方の層が接着性樹脂を含有し、かつ、Ｘ線入射方向に対して直交する面の少なくとも一方の面が支持体により保持されてなることを特徴とするタルボ用格子。
Patent WO-2020208890-A1 (WO)
Inventor: YAMAGUCHI HIROSHI
IPC: B60R16/02
Filed: 2020-01-21
Abstract: The purpose of the present invention is to enable changing or addition of a connection device in a vehicle to be easily dealt with and to allow miniaturization of a power supply signal distribution device as much as possible. This wiring system is provided with: a power supply signal distribution device that provides multiple distribution lines to each of a power supply circuit and a signal circuit; a distribution connector that includes a plurality of connector parts; and an intermediate wiring member that includes an intermediate power supply line and an intermediate signal line. In the distribution connector, the power supply circuit and the signal circuit each include lines distributed to the plurality of connector parts. A distribution destination line of the power source circuit in the power supply signal distribution device and a distribution source line of the power source circuit in the distribution connector are connected together through the intermediate power supply line. A distribution destination line of the signal circuit in the power supply signal distribution device and a distribution source line of the signal circuit in the distribution connector are connected together through the intermediate signal line.
Patent WO-2020162178-A1 (WO)
Title: トナー搬送装置及び画像形成装置
Inventor: MIZUTANI NAOKI
IPC: G03G21/10
Filed: 2020-01-22
Abstract: 画像形成装置（１）は、トナー搬送路（３４）を有する筐体（２１）と、前記トナー搬送路（３４）内のトナーを所定の搬送方向に搬送するスクリュー（２４）と、前記スクリュー（２４）の前記搬送方向下流側の端部を軸支する下流側軸受（２５）と、を備え、前記スクリュー（２４）は、前記搬送方向に沿って延びるシャフト（５１）と、前記シャフト（５１）の外周面に設けられる螺旋状のフィン（５２）と、を有し、前記シャフト（５１）は、前記下流側軸受（２５）に挿入される下流側挿入部（５４）を有し、前記下流側挿入部（５４）の外径は、前記フィン（５２）の前記搬送方向下流側の端部の外径よりも大きい。
Patent WO-2020162367-A1 (WO)
Title: 配管保護装置および冷却装置
Inventor: ISOYA Satoshi
IPC: G06F1/20
Filed: 2020-01-31
Abstract: 熱交換ユニットへ熱交換媒体を供給する供給管の端部に設けられた供給側カプラと、前記供給管から前記熱交換ユニットへ供給された前記熱交換媒体が排出される排出管の端部に設けられた排出側カプラとに設けられる配管保護装置であって、前記供給管の一部の輪郭に沿った凹部を備える供給側支持部と、前記排出管の一部の輪郭に沿った凹部を備える排出側支持部と、前記供給側支持部、及び前記排出側支持部を所定の間隔を空けて支持するとともに、サーバを構成する筐体に連結する連結部と、有する配管保護装置。
Patent WO-2020230378-A1 (WO)
Inventor: TAKATORI Iori
IPC: B41F17/22
Filed: 2020-02-04
Abstract: 印刷機の状態を正確に把握し、異常を監視することである。　印刷機１は、版胴１３に装着される印刷版１４と、印刷版１４に供給されたインキを被印刷物Ｐに転写するブランケット２５と、ブランケット２５を回転させるブランケットホイール２０と、を備える。印刷機１は、ブランケットホイール２０の内部に設けられ、ブランケットホイール２０に対する印刷版１４の距離を測定する距離センサ７１、及び／又は、ブランケットホイール２０の内部に設けられ、印刷版１４の温度を測定する温度センサ７５を備えることを特徴とする。
Patent WO-2020162518-A1 (WO)
Inventor: YAMAMOTO MASAYUKI
IPC: C09J11/06
Filed: 2020-02-06
Abstract: Provided are: an adhesive sheet having excellent outgas resistance; and a layered product comprising the adhesive sheet. This adhesive sheet comprises an adhesive agent layer. The adhesive agent layer contains a crosslinked (meth)acrylic copolymer, a polymerizable monomer having a polymerizable double bond in the molecule, and a photopolymerization initiator. The crosslinked (meth)acrylic copolymer has a structure in which a crosslinkable (meth)acrylic copolymer is crosslinked by a crosslinking agent. The polymerizable monomer includes a monofunctional monomer having a cyclic ether structure and/or a monofunctional monomer having a chain ether structure.
Patent WO-2020217647-A1 (WO)
Inventor: TESHIMA KAZUKIYO
IPC: F04B43/02
Filed: 2020-02-07
Abstract: Selon l'invention, un diaphragme à enroulement 5 d'une pompe 1 à diaphragme à enroulement comprend : une partie mobile 31 qui est apte à subir un mouvement de va-et-vient d'un seul tenant avec un piston 3 ; une partie fixe 32 fixée dans un logement 2 ; et une partie de film mince 33 qui relie la partie mobile 31 et la partie fixe 32 et qui fléchit du fait du mouvement de va-et-vient du piston 3. Une couche de caoutchouc 6 est superposée sur la partie de film mince 33 sans y adhérer, une partie d'extrémité 6a de la couche de caoutchouc 6 située du côté partie mobile 31 est fixée au piston 3, et une partie d'extrémité 6b de la couche de caoutchouc 6 se trouvant du côté partie fixe 32 est fixée au boîtier 2.
Patent WO-2020189226-A1 (WO)
Inventor: ICHIHASHI NAOTO
IPC: A47L9/22
Filed: 2020-02-28
Abstract: The present invention makes it possible to provide a blower with reduced noise by increasing the length of an air channel in the housing while making the product compact. Provided is a blower having a cylindrical housing 2 that has a long direction, a motor 10 that is accommodated in the housing, and a fan 15 that is rotated by the motor and that generates an airflow, wherein an intake port 20 is provided near the front end of a handle 4 and the interior of the handle 4 is used as an air intake channel. Air taken in from the intake port 20 flows as indicated by arrows C2, F2, turns at a rear end connection 4c in the handle 4, flows as indicated by arrow F1, which is the opposite direction of arrow F2, and reaches the fan 15. The air that passes through the fan 15 is discharged toward the front from a discharge port 6.
Patent WO-2020189256-A1 (WO)
Title: Coated cutting tool
Inventor: ISAKA MASAKAZU
IPC: B23B27/14
Filed: 2020-03-03
Abstract: This coated cutting tool has a hard coating including: a b-layer comprising a nitride or a carbonitride; a c-layer which is a layered coating comprising, layered alternately with a film thickness of 50 nm or less each, a c1-layer of a nitride or a carbonitride containing Al at between 55% by atom and 75% by atom inclusive, Cr at a large content ratio, and further, at least Si, and a c2-layer of a nitride or a carbonitride containing Al at between 55% by atom and 75% by atom inclusive, and containing Ti in a large amount; and a d-layer that is a nitride or a carbonitride containing, relative to the total amount of metal (including metalloid) elements, Al at between 55% by atom and 75% by atom inclusive, Cr at a large content ratio, Cr at a content ratio of 20% by atom or greater, and further, at least Si. The peak intensity Ih attributed to the hcp (010) plane of AlN in the c-layer, and the total peak intensity Is attributed to a plurality of predetermined crystal phases, fulfill the relationship Ih×100/Is ≤ 15.
Patent WO-2020209005-A1 (WO)
Inventor: MURAMATSU TAKAO
IPC: F21W103/00
Filed: 2020-03-13
Abstract: This vehicle system (2) is provided with a vehicular lamp (42H), an information acquisition unit (6) for acquiring vehicle peripheral information, and a vehicle control unit (3). The vehicle lamp (42H) has: a first light source (44) for emitting visible light; a second light source (45) for emitting infrared light; a rotary reflector that rotates while reflecting visible light and infrared light and scans the visible light and the infrared light along a horizontal direction on a virtual vertical screen; a light-receiving unit (47) that receives the return light of the infrared light reflected from the periphery of the vehicle; and a lamp control unit (43) that controls the light sources (44, 45), the rotary reflector, and the light-receiving unit (47). Either the vehicle control unit (3) or the lamp control unit (43) is configured to acquire the positional information of a target outside the vehicle on the basis of the vehicle peripheral information acquired by the information acquisition unit (6), and correct the positional information on the basis of the information about the returned light of the infrared light received by the light-receiving unit (47).
Patent WO-2020196084-A1 (WO)
Inventor: OHNISHI RYOTA
IPC: G08G1/00
Filed: 2020-03-17
Abstract: This information processing method is an information processing method executed using a computer, wherein: driving skill is acquired, the driving skill being whether or not a person riding in an autonomously driven vehicle (5) can drive a manually drivable vehicle (5) and/or the degree to which the person can drive the autonomously driven vehicle (5); individual specifications relating to autonomous driving of a plurality of autonomously driven vehicles (5) are acquired; a route for delivering a person is acquired; individual deviation risks are acquired on the basis of the specifications and the route, said risks including the possibility that an automatic driving system including the autonomously driven vehicle (5) will deviate from an operating design range and/or the degree of deviation therefrom; the autonomously driven vehicle (5) allocated for delivering a person is selected from the plurality of autonomously driven vehicle (5) in accordance with the individual deviation risk and the driving skill; and notification of the selected autonomously driven vehicle (5) is issued.
Patent WO-2020204004-A1 (WO)
Title: Highly reliable data transaction system, and highly reliable data transaction method
Inventor: OGAWA AKITO
IPC: G06F21/31
Filed: 2020-03-30
Abstract: [Problem] To provide a highly reliable data transaction system having a distributed network and a highly reliable data transaction method. [Solution] A highly reliable data transaction system, which includes a distributed network, is provided with: an authentication means which performs authentication via a medical institute; a first acquisition means which acquires examination information about an examinee; a highly reliable data generation means which generates highly reliable data about the examinee; a first recording means which records the generated highly reliable data to a block connected by a blockchain constructed in the distributed network; and a first distribution means which distributes, to users, a portion or the entirety of the highly reliable data according to the transaction information.
Patent WO-2020209137-A1 (WO)
Title: Method for producing cardiac muscle cells
Inventor: TANABE KOJI
IPC: C12N5/10
Filed: 2020-03-31
Abstract: This method for producing cardiac muscle cells comprises: preparing stem cells; and inducing the stem cells into cardiac muscle cells by introducing a Sendai virus into the stem cells through infection and causing the Sendai virus to express mRNA for synthesizing an inducing factor inside the stem cells.
Patent WO-2020218415-A1 (WO)
Inventor: LEE TAEWOO
IPC: H04W72/12
Filed: 2020-04-23
Abstract: In the present invention, system information is received and a PUCCH is transmitted, the system information specifies one PUCCH resource set from among a plurality of PUCCH resource sets, the plurality of PUCCH resource sets includes at least a first PUCCH resource set and a second PUCCH resource set, the first PUCCH resource set includes a first PUCCH resource, the initial symbol of the first PUCCH resource belongs to a set of first initial symbols, the set of first initial symbols includes initial symbols, the second PUCCH resource set includes a second PUCCH resource, the initial symbol of the second PUCCH resource belongs to a set of second initial symbols, the set of second initial symbols includes only one initial symbol.
Patent WO-2021224977-A1 (WO)
Title: Light amplification device and light amplification method
Inventor: TAKESHITA HITOSHI
IPC: H01S3/10
Filed: 2020-05-08
Abstract: The present invention addresses the problem that, when an optical amplification device having a plurality of optical transmission paths, such as multi-core optical fibers, is used for bidirectional communication, it is difficult to construct an optical transmission system optimized for all of signal lights having different transmission directions. The optical amplification device of the present invention comprises: an optical guide means having a plurality of optical transmission paths including an optical amplification medium having a gain in the wavelength band of a signal light; an excitation light introducing means for introducing excitation light for exciting the optical amplification medium into the optical guide means from both ends of the optical guide means; and a residual excitation light introducing means for introducing residual excitation light output from both ends of the optical guide means and having a wavelength component of the excitation light into the optical guide means.
Patent WO-2020241406-A1 (WO)
Title: Processing device, processing method, and program
Inventor: UEJI Atsushi
IPC: D06F58/32
Filed: 2020-05-20
Abstract: The present invention provides a processing device (10) comprising: a registration unit (11) that acquires biological information and stores the information in a storage unit (12); a reception unit (13) that receives a request to unlock the door of a washing/drying machine and the input of biological information; an authentication unit (14) that performs biometric authentication on the basis of the biological information stored in the storage unit (12) and the biological information received by the reception unit (13); and a lock control unit (15) that inputs an instruction to unlock the door to the washing/drying machine in the case of successful biometric authentication.
Patent WO-2020235606-A1 (WO)
Inventor: SUGO MICHIHIRO
IPC: H01L21/304
Filed: 2020-05-20
Abstract: A cleaning fluid for substrate temporary adhesives for substrates that includes: a tetrabutyl ammonium fluoride; a dimethyl sulfoxide; and liquid compound having a hetero atom and having a solubility parameter of 8.0-10.0. The tetrabutyl ammonium fluoride content is ideally 1%-15% by mass, relative to 100% by mass of the total tetrabutyl ammonium fluoride, dimethyl sulfoxide, and liquid compound content. The dimethyl sulfoxide content is ideally 5%-30% by mass, relative to 100% by mass of the total tetrabutyl ammonium fluoride, dimethyl sulfoxide, and liquid compound content.
Patent WO-2021234905-A1 (WO)
Title: Learning data generation device, model learning device, learning data generation method, and program
Inventor: ASHIHARA TAKANORI
IPC: G10L15/06
Filed: 2020-05-21
Abstract: Provided is a learning data generation device, etc., that generates learning data for learning an acoustic model that simulates robustness for perception of a human voice. The learning data generation device generates learning data for use when learning an acoustic model used in a voice recognition device. The learning data generation device includes a signal conversion unit that converts a first learning voice signal to a second learning voice signal, which is a voice signal that can produce an acoustic illusion.
Patent WO-2021245887-A1 (WO)
Inventor: NAKAMURA YOSUKE
IPC: G06Q10/10
Filed: 2020-06-04
Abstract: This control method acquires contract data including the company name of a company as a counterparty to a contract and the job title of an authorizer, refers to a storage unit in which information (141) showing a plurality of types of approval abilities according to job titles in companies is stored in association with the company names and the job titles, to acquire information (103) showing an approval ability associated with the company name and the job title included in the acquired contract data, and presents the information (103) showing the acquired approval ability, in association with the acquired contract data.
Patent WO-2021149279-A1 (WO)
Inventor: KATAGUCHI TAKASHI
IPC: G11B5/714
Filed: 2020-07-01
Abstract: 平均粒子体積が小さい磁性粉を含む磁気記録媒体の保存安定性の向上を目的とする。　本開示は、基体と、前記基体上に設けられ、磁性粉を含む磁性層とを備えており、前記磁性粉の平均粒子体積Ｖが２０００ｎｍ 3 以下であり、磁気記録媒体の平均厚みｔ Ｔ が５．３μｍ以下である、前記磁気記録媒体の熱安定性Ｋ u Ｖ act ／ｋ B Ｔが６０以上であり、パルス磁界を用いて測定した前記磁気記録媒体の残留保磁力Ｈｒｐと前記磁気記録媒体の垂直方向における保磁力Ｈｃ１との比Ｈｒｐ／Ｈｃ１が、２．１０以下である、テープ状の磁気記録媒体を提供する。
Patent WO-2021006194-A1 (WO)
Inventor: KURASAWA HIROKI
IPC: C03B11/08
Filed: 2020-07-03
Abstract: A mold for forming a glass lens, which comprises a molding part having a molding surface for forming a lens surface of the glass lens and a holding part for positioning and holding the molding part and by which the glass lens is formed by pressing a glass material to be molded along the moving direction of the mold, wherein the holding part and the molding part have positioning surfaces for engaging the holding part and the molding part together at the molding temperature of the glass material to be molded, i.e., the material for forming the glass lens, to thereby determine the position of the molding part relative to the holding part, and the following requirements are satisfied: (1) 60°≤θ≤90° and (2) L≥DM(90-θ/180) [where: θ stands for the tilt angle of the positioning surfaces relative to the direction perpendicular to the moving direction of the mold in a plane including the central axis which passes through the centers of the molding part and the holding part toward the moving direction of the mold; L stands for the engagement length of the positioning surfaces being in contact; and DM stands for the maximum outer diameter of the molding part].
Patent WO-2021049150-A1 (WO)
Title: Binder composition for forming mold
Inventor: KANZAWA TOMOFUMI
IPC: B22C1/22
Filed: 2020-07-09
Abstract: The present invention is a binder composition for forming a mold, said binder composition containing a phenolic resin and a cyclic ketal compound having a hydroxyl group and 5 or more carbon atoms. The present invention is able to provide a binder composition for forming a mold, said binder composition being capable of enhancing the degradability of a mold, namely being capable of decreasing the residual mold pressure strength, thereby improving the productivity of the flask removal work after casting.
Patent WO-2020230907-A1 (WO)
Inventor: SASAKI HIKARI
IPC: G10K11/165
Filed: 2020-07-14
Abstract: 無機繊維と、有機バインダーとを含み、無機繊維の平均繊維径が２．０μｍ以下であり、無機繊維の含有量が９０質量％以上であり、有機バインダーの含有量が０．５質量％以上１０質量％以下であり、有機バインダーがエラストマーを含み、かさ密度が３０ｋｇ／ｍ３以下である、多孔体。
Patent WO-2022018825-A1 (WO)
Inventor: JO TERUO
IPC: G02F1/01
Filed: 2020-07-21
Abstract: 出力回路（１０４ａ）は、トランジスタ（Ｑ１００～Ｑ１０３）と、耐圧保護回路（３００）とから構成される。耐圧保護回路（３００）は、正相側の出力信号端子（Ｖｏｕｔｐ）と逆相側の出力信号端子（Ｖｏｕｔｎ）との間に接続された抵抗（Ｒ１０２，Ｒ１０３）と、抵抗（Ｒ１０４，Ｒ１０５）と、スイッチ（ＳＷ１）とから構成される。スイッチ（ＳＷ１）は、ゲート端子が抵抗（Ｒ１０４，Ｒ１０５）の接続点に接続され、ドレイン端子がバイアス電圧（Ｖｃｓ）に接続され、ソース端子がトランジスタ（Ｑ１０４）のベース端子に接続されたＮＭＯＳトランジスタ（Ｑ１０５）からなる。
Patent WO-2021100260-A1 (WO)
Inventor: TANI MASAKAZU
IPC: H04B1/40
Filed: 2020-08-04
Abstract: The present invention suppresses variation between the impedances in the communication bands of a plurality of filters viewed from an antenna terminal. In a high frequency circuit (1), a first switch (4) is connected to an antenna terminal (2). A second switch (3) is connected to the antenna terminal (2) via the first switch (4). A first filter (6) is an elastic wave filter connected to the first switch (4) via the second switch (3), and passes a high frequency signal in a first communication band. A second filter (7) is an elastic wave filter connected to the first switch (4) not via the second switch (3), and passes a high frequency signal in a second communication band that is higher in frequency than the first communication band. The high frequency circuit (1) is further provided with a capacitor (8). The capacitor (8) is between the first switch (4) and the second switch (3) and is connected in series to the first switch (4) and the second switch (3).
Patent WO-2021049217-A1 (WO)
Title: Polarizer
Inventor: HONSHO YOSHIHITO
IPC: H01L27/32
Filed: 2020-08-06
Abstract: [Problem] To provide a polarizer which is suppressed in the occurrence of a crack in a dew condensation/heat shock test wherein low-temperature dew condensation conditions (-40°C) and high-temperature conditions (85°C) are repeated, wherein a portion, where iodine loss has occurred, in the edge region is not noticeable. [Solution] A polarizer which is a resin film containing boric acid and iodine, wherein: a low boric acid concentration part, where the boric acid concentration is lower than the boric acid concentration in an inner region that is positioned 500 μm or more inside from the edge, is formed in a region including the edge when viewed in plan; a low iodine concentration part, where the iodine concentration is lower than the iodine concentration in the inner region, is formed in the region including the edge; and the length of the low iodine concentration part from the edge is from 19 μm to 100 μm. [Selected drawing] None
Patent WO-2021039408-A1 (WO)
Title: 加硫ゴム組成物、加硫ゴム組成物の製造方法及びタイヤ
Inventor: ASAKURA TAKAFUMI
IPC: C08L9/00
Filed: 2020-08-12
Abstract: 耐亀裂進展性に優れた加硫ゴム組成物を提供することを目的とする。　上記課題を解決するべく、本発明は、天然ゴム及び／又は合成イソプレンゴムからなるゴム成分と、シンジオタクチック１，２－ポリブタジエンと、シリカと、を含み、前記ゴム成分マトリクス中に、網目状の３次元ネットワークが形成され、該網目状の３次元ネットワークは、前記ｓＰＢの結晶からなる部分、及び、前記ゴム成分と前記ｓＰＢとが相溶した部分を有することを特徴とする。
Patent WO-2021033634-A1 (WO)
Title: Optical film
Inventor: MARUYAMA AKIRA
IPC: H05B33/02
Filed: 2020-08-14
Abstract: The present invention provides an optical film in which excellent adhesion between a resin substrate and an optically anisotropic layer is obtained, and in which the occurrence of optical defects in the optically anisotropic layer is suppressed. This optical film has a resin substrate having an alignment-regulating force, and an optically anisotropic layer positioned on the resin substrate, wherein the optically anisotropic layer includes a liquid crystal compound and a compound which differs from the liquid crystal compound and which has a hetero atom, and when a component of the optical film in the depth direction thereof is analyzed by time-of-flight secondary ion mass spectrometry while the optical film is irradiated by an ion beam from a first surface to a second surface, the first surface being the surface of the optical film on the optically anisotropic layer side thereof, and the second surface being the surface of the optical film on the resin substrate side thereof, the obtained profile satisfies a predetermined condition.
Patent WO-2021106296-A1 (WO)
Title: 消音器、及び、当該消音器を備える家電製品
Inventor: WATANABE MASANORI
IPC: G10K11/175
Filed: 2020-08-28
Abstract: 消音器（２０１）は、内部が空洞の複数の音響管（２０２）を内蔵する胴体部（２１０）を備えている。胴体部の中央部には、モータ（１０１）のハウジング（１０１ａ）を通すための開口部（２１１）が形成されている。それぞれの音響管は、開口した一端部（Ａ１）と、閉口した他端部（Ａ２）と、を有しており、かつ、一端部が開口部の方向を向き、他端部が胴体部の外周面の方向を向くように配置されている。
Patent WO-2021049530-A1 (WO)
Title: Wear-resistant alumina sintered body
Inventor: SUGIMOTO TAKESHI
IPC: C04B35/10
Filed: 2020-09-09
Abstract: The present invention addresses the problem of providing an alumina sintered body which has excellent impact resistance as well as wear resistance and in which the occurrence of cracking or chipping due to impact is suppressed. A wear-resistant alumina sintered body according to the present invention contains Al 2 O 3  as a main component, and contains SiO 2 , CaO and MgO in a total amount of 5.0-10.0 wt%, wherein: when the total content of Al 2 O 3 , SiO 2 , CaO and MgO forming the glass phases of alumina grain boundaries is 100 wt%, the content of Al 2 O 3  is 16.0-23.0 wt%, the content of SiO 2  is 65.0-79.0 wt%, the content of CaO is 2.0-6.0 wt%, the content of MgO is 2.0-8.0 wt%, and the content of unavoidable impurities are at most 0.5 wt%; the alumina sintered body has a porosity of at most 3.0%; the average diameter of the glass phases is at most 0.5 μm; the content percentage of the glass phases is 3.0-10.0% with respect to the entirety of the alumina sintered body; and the alumina sintered body has an average crystal grain size of 0.8-2.0 μm and a maximum crystal grain size of at most 6.0 μm.