Abstract: A heat amount measuring method includes a first step of providing a heat-transferring component that transfers and receives heat to and from a heating component and measuring, while the heating component is generating heat, a first heat amount of heat transmitted from the heating component to the heat-transferring component, a first heating component temperature, and a first substrate temperature, a second step of changing an output of the heat-transferring component and measuring a second heat amount of heat transmitted from the heating component to the heat-transferring component, a second heating component temperature, and a second substrate temperature, and a third step of calculating a heat amount of heat transmitted from the heating component to a substrate by using the first heat amount, the first heating component temperature, the first substrate temperature, the second heat amount, the second heating component temperature, and the second substrate temperature.

Abstract: A heat amount measuring method includes a first step of providing a heat-transferring component that transfers and receives heat to and from a heating component and measuring, while the heating component is generating heat, a first heat amount of heat transmitted from the heating component to the heat-transferring component, a first heating component temperature, and a first substrate temperature, a second step of changing an output of the heat-transferring component and measuring a second heat amount of heat transmitted from the heating component to the heat-transferring component, a second heating component temperature, and a second substrate temperature, and a third step of calculating a heat amount of heat transmitted from the heating component to a substrate by using the first heat amount, the first heating component temperature, the first substrate temperature, the second heat amount, the second heating component temperature, and the second substrate temperature.

Abstract: A drive device includes a housing in which a gas is sealed, wherein density of the gas is lower than density of air, a driven object housed inside the housing, a driver configured to drive the driven object, a current detector configured to detect a value of a current flowing into the driver, and a determinator configured to determine a concentration of the gas inside the housing based on the value of the current detected.

Abstract: A generated-heat-quantity measuring method is a method that measures a generated heat quantity of a heat generating component mounted on a substrate.

Abstract: A heat amount measuring method includes a first step of providing a heat-transferring component that transfers and receives heat to and from a heating component and measuring, while the heating component is generating heat, a first heat amount of heat transmitted from the heating component to the heat-transferring component, a first heating component temperature, and a first substrate temperature, a second step of changing an output of the heat-transferring component and measuring a second heat amount of heat transmitted from the heating component to the heat-transferring component, a second heating component temperature, and a second substrate temperature, and a third step of calculating a heat amount of heat transmitted from the heating component to a substrate by using the first heat amount, the first heating component temperature, the first substrate temperature, the second heat amount, the second heating component temperature, and the second substrate temperature.

Abstract: A drive device includes a housing in which a gas is sealed, wherein density of the gas is lower than density of air, a driven object housed inside the housing, a driver configured to drive the driven object, a current detector configured to detect a value of a current flowing into the driver, and a determinator configured to determine a concentration of the gas inside the housing based on the value of the current detected.

Abstract: A phosphor wheel includes: a substrate having a first main surface, a second main surface opposite to the first main surface, and an open portion; a phosphor layer provided on the first main surface; and a fin provided on the second main surface. The fin is nearer a center of the substrate than the phosphor layer is, and the open portion is located between the phosphor layer and the fin.

Abstract: A disk-shaped substrate made of a heat conductive material is provided with, along an outer periphery of one surface of the substrate, a ring-shaped phosphor that emits light by irradiation with blue laser light that is excitation light. The substrate is provided with, on another surface of the substrate, a plurality of convex portions dotting a region corresponding to a region provided with the phosphor. In a phosphor wheel, the substrate is driven by a motor to rotate about an axis of rotation.

Abstract: A phosphor wheel includes: a substrate having a first main surface, a second main surface opposite to the first main surface, and an open portion; a phosphor layer provided on the first main surface; and a fin provided on the second main surface. The fin is nearer a center of the substrate than the phosphor layer is, and the open portion is located between the phosphor layer and the fin.

Abstract: A disk-shaped substrate made of a heat conductive material is provided with, along an outer periphery of one surface of the substrate, a ring-shaped phosphor that emits light by irradiation with blue laser light that is excitation light. The substrate is provided with, on another surface of the substrate, a plurality of convex portions dotting a region corresponding to a region provided with the phosphor. In a phosphor wheel, the substrate is driven by a motor to rotate about an axis of rotation.

Abstract: A housing stores a heat generator that rotates around a rotation axis. The housing includes a corrugated structure provided on a left wall and a right wall, which are parallel to the rotation axis, the corrugated structure being formed by distorting the left wall and the right wall.