Abstract: According to one embodiment, an encryption communication system configures a network with a plurality of nodes, and shares the encryption key between a first node that delivers the encryption key to a first user and a second node that delivers the encryption key to a second user. The first node forms n (n>1) systems of paths to the second node over the network, generates n pieces of first data, distributes the n pieces of first data to the n systems of paths and transmits the n pieces of first data to the second node, and generates the encryption key by superimposing the n pieces of first data. The second node receives the n pieces of first data from the first node via the n systems of paths, and generates the encryption key by superimposing the n pieces of first data.

Abstract: A lens barrel (10) comprises a lens mount unit (20a), a retractable lens frame (18b), a seventh lens group unit (18), three cam pins (18ad), guide shafts (18af), a pressing member (18d), and a compression spring (18ag). At least two of the guide shafts (18af) are provided to the seventh group unit (18) and are disposed in the optical axis (X). The compression spring (18ag) applies a biasing force that biases the retractable lens frame (18b) against the pressing member (18d) in the optical axis (X) direction, and expands and contracts when a teleconverter (30) is mounted to the lens mount unit (20a), causing the retractable lens frame (18b) to retract to the subject side in the optical axis (X) direction.

Abstract: A europium-doped ?-sialon phosphor, in which, when the ratio of an aluminum element at a depth of 8 nm from the surface of the phosphor, which is obtained by X-ray photoelectron spectroscopy, is indicated by P8 [at %], and the ratio of an aluminum element at a depth of 80 nm from the surface of the phosphor is indicated by P80 [at %], P8/P80?0.9 is satisfied. A light emitting device containing this ?-sialon phosphor.

Abstract: A virtual image display device includes a display surface and a projection optical system that projects a light ray from the display surface toward a transparent member. The projection optical system includes a convex lens. An optical path of a first light ray, which is emitted from one point on the display surface and is reflected by the front surface of the transparent member coincides with an optical path of a second light ray, which is emitted from the one point and is reflected by the back surface of the transparent member, due to refraction in the convex lens. The center of the convex lens is displaced from a reference axis Z that passes through the one point and extends in a direction perpendicular to the display surface. The display surface is positioned closer to the convex lens than a focal point of the projection optical system.

Abstract: A ?-sialon phosphor represented by general formula: Si6-zAlzOzN8-z (0<z<4.2) has as a host crystal, a crystal structure identical to that of a ?-sialon crystal phase and having a bulk density of 0.80 g/cm3 or more and 1.60 g/cm3 or less. Also, a light-emitting element includes the ?-sialon phosphor and a semiconductor light-emitting element capable of exciting the ?-sialon phosphor.

Abstract: According to one embodiment, an encryption communication system configures a network with a plurality of nodes, and shares the encryption key between a first node that delivers the encryption key to a first user and a second node that delivers the encryption key to a second user. The first node forms n (n>1) systems of paths to the second node over the network, generates n pieces of first data, distributes the n pieces of first data to the n systems of paths and transmits the n pieces of first data to the second node, and generates the encryption key by superimposing the n pieces of first data. The second node receives the n pieces of first data from the first node via the n systems of paths, and generates the encryption key by superimposing the n pieces of first data.

Abstract: According to one embodiment, a user base device A has a cryptographic module a key sharing module. The key sharing module restores and disperses a cryptographic key used to generate the encrypted data. The key sharing module includes a quantum cryptographic communication device applicable to a plurality of front ends. The front ends are used to receive dispersed cryptographic key from different routes, and to output dispersed cryptographic key to different routes.

Abstract: According to one embodiment, in an encryption communication system, a first device and a second device that execute encryption communication via a first network share an encryption key used for the encryption communication via a second network including a plurality of nodes. The first device generates n pieces of first data used for generating the encryption key, transmits the n pieces of first data to the second device by distributing the n pieces of first data to n nodes among the nodes and sending the n pieces of first data to the second network, and generates the encryption key by using the n pieces of first data. The second device receives the n pieces of first data from n nodes among the nodes, and generates the encryption key by using the n pieces of first data.

Abstract: A phosphor powder contains an EU-activated ?-type sialon phosphor particles. When a median diameter in the phosphor powder having not been subjected to an ultrasonic homogenizer treatment is set as D1 and a median diameter in the phosphor powder having been subjected to an ultrasonic homogenizer treatment is set as D2, 1.05?D1/D2?1.70. A dispersion liquid in which 30 mg of the phosphor powder is uniformly dispersed in 100 ml of a 0.2% concentration of a sodium hexametaphosphate aqueous solution is added to a columnar container of which a bottom surface has an inner diameter of 5.5 cm. Then, the dispersion liquid is irradiated with ultrasonic waves for 3 minutes at a frequency of 19.5 kHz, and an output of 150 W, in a state where a cylindrical tip, which has an outer diameter of 20 mm, of an ultrasonic homogenizer is immersed in the dispersion liquid in ?1.0 cm.

Abstract: According to one embodiment, a first key sharing module outputs a common key, a first cryptographic module encrypts plaintext data and outputs encrypted data. A first transmission system transmits the encrypted data. A second transmission system transmits the common key. A monitor device is disposed in the first transmission system, and receives transmission condition data from a first base and reception condition data from a second base, and performs matching of the transmission condition data and the reception condition data.

Abstract: A ?-sialon phosphor that is a solid solution of europium, in which D50 is 7.0 ?m or more and 20.0 ?m or less and (D50?D10)/D50 is 0.60 or less, where D50 is a 50% area diameter of primary particles of the ?-sialon phosphor, and D10 is a 10% area diameter of the primary particles of the ?-sialon phosphor. Primary particles are defined as single-crystal particles distinguished for each crystal orientation by identifying the crystal orientation of individual particles of the ?-sialon phosphor by an electron backscatter diffraction image method. D50 and D10 are obtained by image analysis of the cross-sectional area of the primary particles.

Abstract: A europium-doped ?-sialon phosphor particle. When the element concentration of a Si atom on the surface portion of the particle that is obtained by analyzing a cross section of the phosphor particle by the energy dispersive X-ray analysis method is indicated by Ps [at %], and the element concentration of a Si atom near the center of the particle that is obtained by an analysis by the same method is indicated by Pc [at %], the Pc-Ps value is 3 at % or more.

Abstract: A europium-doped ?-sialon phosphor, in which, when the ratio of an aluminum element at a depth of 8 nm from the surface of the phosphor, which is obtained by X-ray photoelectron spectroscopy, is indicated by P8 [at %], and the ratio of an aluminum element at a depth of 80 nm from the surface of the phosphor is indicated by P80 [at %], P8/P80?0.9 is satisfied. A light emitting device containing this ?-sialon phosphor.

Abstract: A phosphor powder contains an EU-activated ?-type sialon phosphor particles. When a median diameter in the phosphor powder having not been subjected to an ultrasonic homogenizer treatment is set as D1 and a median diameter in the phosphor powder having been subjected to an ultrasonic homogenizer treatment is set as D2, 1.05?D1/D2?1.70. A dispersion liquid in which 30 mg of the phosphor powder is uniformly dispersed in 100 ml of a 0.2% concentration of a sodium hexametaphosphate aqueous solution is added to a columnar container of which a bottom surface has an inner diameter of 5.5 cm. Then, the dispersion liquid is irradiated with ultrasonic waves for 3 minutes at a frequency of 19.5 kHz, and an output of 150 W, in a state where a cylindrical tip, which has an outer diameter of 20 mm, of an ultrasonic homogenizer is immersed in the dispersion liquid in ?1.0 cm.

Abstract: A ?-sialon phosphor that is a solid solution of europium, in which D50 is 7.0 ?m or more and 20.0 ?m or less and (D50?D10)/D50 is 0.60 or less, where D50 is a 50% area diameter of primary particles of the ?-sialon phosphor, and D10 is a 10% area diameter of the primary particles of the ?-sialon phosphor. Primary particles are defined as single-crystal particles distinguished for each crystal orientation by identifying the crystal orientation of individual particles of the ?-sialon phosphor by an electron backscatter diffraction image method. D50 and D10 are obtained by image analysis of the cross-sectional area of the primary particles.

Abstract: A vehicle display device includes a display configured to display a video; a first mirror configured to reflect the video displayed in the display; and a second mirror configured to reflect the video reflected on the first mirror, wherein a distance from eye point of occupant of vehicle to a reflecting image formed by the second mirror is optically extended such that it becomes longer than a distance from the eye point of the occupant to a display surface of the display.

Abstract: A virtual image display device includes: a display unit that generates an image display light by modulating an illumination light; and a projection optical system that includes a concave mirror for reflecting the image display light toward a virtual image presentation plate and a convex lens provided between the display unit and the concave mirror. The display unit is provided at a position closer to the convex lens than a focal point, within a meridional plane, of a composite optical system formed by the virtual image presentation plate and the projection optical system.

Abstract: According to one embodiment, a first decoding circuit calculates likelihood information by executing Viterbi decoding using a parameter for normalizing a branch metric on a signal sequence read from a magnetic disk. The second decoding circuit generates a first bit data sequence by iterative decoding using the likelihood information, and executes a check using a parity check matrix on the first bit data sequence. The control circuit causes the first decoding circuit and the second decoding circuit to repeatedly execute decoding, and updates the parameter in accordance with a check result obtained every time the decoding by the first decoding circuit and the second decoding circuit is executed. An acquisition circuit acquires numerical information corresponding to the number of bit errors included in the first bit data sequence obtained when the number of times of executions of the decoding is equal to a first value.

Abstract: A ?-sialon phosphor represented by general formula: Si6?zAlzOzN8?z (0<z<4.2) has as a host crystal, a crystal structure identical to that of a ?-sialon crystal phase and having a bulk density of 0.80 g/cm3 or more and 1.60 g/cm3 or less. Also, a light-emitting element includes the ?-sialon phosphor and a semiconductor light-emitting element capable of exciting the ?-sialon phosphor.

Abstract: According to one embodiment, a first decoding circuit calculates likelihood information by executing Viterbi decoding using a parameter for normalizing a branch metric on a signal sequence read from a magnetic disk. The second decoding circuit generates a first bit data sequence by iterative decoding using the likelihood information, and executes a check using a parity check matrix on the first bit data sequence. The control circuit causes the first decoding circuit and the second decoding circuit to repeatedly execute decoding, and updates the parameter in accordance with a check result obtained every time the decoding by the first decoding circuit and the second decoding circuit is executed. An acquisition circuit acquires numerical information corresponding to the number of bit errors included in the first bit data sequence obtained when the number of times of executions of the decoding is equal to a first value.