Abstract: A virtual image display device includes an image element configured to display an image, a first lens disposed in an extraction position of image light and including at the image element side thereof a convex surface, a second lens disposed further toward the image element side than the first lens and including a concave surface bonded to the convex surface of the first lens, a half mirror provided in a bonding portion for bonding together the convex surface and the concave surface, a transmission/reflection selection member provided at a light emitting side of the first lens and configured to selectively perform transmission or reflection of the light depending on a polarization state of the light, and a light-guiding portion keeping close contact between the image element and the second lens and configured to guide the image light.

Abstract: A virtual image display apparatus according to the present disclosure includes a first display module, a second display module, and a coupling portion having an adjustable structure. The adjustable structure adjusts the first display module with respect to the second display module at least a relative rotational position and relative positions in longitudinal and depth directions.

Abstract: A display device includes an image element, a prism mirror that receives image light emitted from the image element through a light incident surface, reflects the image light with an inner reflection surface, and emits the image light from a light emission surface, and a see-through mirror that reflects the image light emitted from the prism mirror toward a pupil position, wherein the prism mirror emits the image light incident from a front to be bent in a direction inclined with respect to the front, and a light emission side of an image source that includes the image element and the prism mirror is covered with a light transmission window that blocks dust.

Abstract: A secondary battery protection circuit for protecting a secondary battery, including: a low-voltage detecting circuit configured to detect a voltage across the secondary battery that is lower than a second voltage for low voltage detection, the second voltage being set to be lower than a first voltage for overdischarge detection; and a switching circuit configured to cause a gate of a charge control NMOS transistor to be fixed at a potential at a high side power supply terminal, upon detecting, by the low-voltage detecting circuit, that the voltage across the secondary battery is lower than the second voltage for low voltage detection.

Abstract: A display device includes an image element, a prism mirror configured to cause imaging light emitted from the image element to be incident on a light incident surface, to reflect the imaging light by an inner reflection surface, and to emit the imaging light from a light emission surface, thereby emitting the imaging light so that the imaging light is returned in an inclined direction, a see-through mirror configured to reflect the imaging light emitted from the prism mirror toward a pupil position, and a basic aperture diaphragm configured to limit the passage of the imaging light incident on the light incident surface of the prism mirror.

Abstract: An optical module according to the present disclosure includes a display element, a first optical member, a second optical member, a third optical member, and an adhesive joints the first optical member and the second optical member. A first optical member includes a first positioning portion that performs a positioning with respect to a second optical member and the second optical member includes a second positioning portion that performs a positioning with respect to the first optical member.

Abstract: A virtual image display apparatus includes a display device (image forming unit), a first mirror member configured to reflect imaging light from the display device, a second mirror member configured to reflect imaging light reflected by the first mirror member, and a third mirror member of a transmissive type configured to reflect imaging light reflected by the second mirror member toward a position of an exit pupil. One of the first mirror member and the second mirror member is a refractive reflective optical member that includes a refractive member including a refractive surface, and a mirror surface formed at a non-refractive surface of the refractive member.

Abstract: A head-mounted display includes a display device, a projection optical member, a prism member, and a light condensing and reflecting surface. The prism member includes a first prism, and a second prism that is disposed further toward an exit pupil side than the first prism. The first prism includes an incident surface, a reflection surface that totally reflects the image light, and a first joining surface that is joined with the second prism via a semi-transmissive reflection surface. The second prism includes a second joining surface that is joined with the first joining surface, and an opposing flat surface that is disposed parallel to the reflection surface to face the reflection surface and configured to transmit the image light, reflected by the semi-transmissive reflection surface and then by the light condensing and reflecting surface and thereafter passing through the semi-transmissive reflection surface.

Abstract: A virtual image display device includes an image generation device, and a concave transmissive mirror configured to reflect image light emitted from the image generation device. A light superimposer is provided on an external side of a partial reflective film provided in the concave transmissive mirror, the light superimposer being configured to superimpose additional light in a visible range on image light transmitted through the partial reflective film.

Abstract: A secondary battery protection circuit for protecting a secondary battery, including: a low-voltage detecting circuit configured to detect a voltage across the secondary battery that is lower than a second voltage for low voltage detection, the second voltage being set to be lower than a first voltage for overdischarge detection; and a switching circuit configured to cause a gate of a charge control NMOS transistor to be fixed at a potential at a high side power supply terminal, upon detecting, by the low-voltage detecting circuit, that the voltage across the secondary battery is lower than the second voltage for low voltage detection.

Abstract: Image formation is performed by using a synthesis optical system, and in a first dichroic film and a second dichroic film that are the synthesis surfaces in the synthesis optical system, a direction in which the cross axis that is the intersecting axis extends corresponds to a direction of alignment of eyes of an observer.

Abstract: An imaging light emitting device, and an optical unit configured to guide imaging light emitted from the imaging light emitting device are included, and the imaging light emitting device emits the imaging light at different densities according to a distortion generated in an optical system constituting the optical unit and an image position.

Abstract: A virtual image display apparatus includes a display device (image forming unit), a lens configured to refract imaging light from the display device, a first mirror member configured to reflect imaging light that passed through the lens, a second mirror member configured to reflect the imaging light reflected by the first mirror member, and a third mirror member of a transmissive type configured to reflect the imaging light reflected by the second mirror member toward a position of an exit pupil. The lens is asymmetric with respect to an optical axis in a first direction corresponding to an eccentric direction defined by the first mirror member and the second mirror member, and is symmetric, across the optical axis, with respect to a second direction orthogonal to the first direction.

Abstract: A display module of the present disclosure includes a display module main body and a housing. The display module main body includes a first, a second display element, and a prism. The housing includes a first, and a second frame. The first frame holds the first display element in a state in which the prism is positioned between a first and a second plate portion, and in which a third plate portion is in contact with the first display element and faces a first surface, and the second frame holds the second display element in a state in which the prism is positioned between a fourth and a fifth plate portion, and in which a sixth plate portion is in contact with the second display element and faces a second surface.

Abstract: Provided are an imaging element configured to display an image, a projection optical system configured to project an image from the imaging element, and a two-stage structural diaphragm including a first diaphragm forming a first aperture portion in the projection optical system, and a second diaphragm forming a second aperture portion in the projection optical system, in which inclinations of a principal ray, relative to an image plane of an imaging element, of imaging light emitted from a peripheral portion of the image plane differ between in a first direction and in a second direction perpendicular to the first direction among in-plane directions of the image plane, in which the first diaphragm and the second diaphragm in the two-stage structural diaphragm are provided at different positions corresponding to differences between the inclinations of the principal ray in the first direction and in the second direction.

Abstract: A light-guiding device includes a pair of light-guiding portions, a pair of light-incident portions that causes image light to be incident on the pair of light-guiding portions respectively, and a pair of light-emitting portions that emit image light, guided by the pair of light-guiding portions, to outside respectively, in which a pair of optical members including the pair of light-guiding portions are coupled by a central member having light transmissivity, and separate overcoat layers are provided at the optical member on one side and at the optical member on another side with respect to an approximate center of the central member.

Abstract: A head-mounted display includes a display device configured to display an image, a diopter adjustment device configured to adjust a diopter, and a correction processing circuit serving as an image correction device configured to correct a display image in accordance with a degree of diopter adjustment. In the adjustments made on a left side and a right side, respectively, after diopter adjustment, the display image is corrected in accordance with the degree of diopter adjustment.

Abstract: A half mirror 21 provided in an optical path bends the optical path, and a semi-transmissive polarizing plate 23 increases the transmittance of image light GL in a direction along alignment of the eyes of an observer while the virtual image display device has a wide angle of view and is downsized, thus reducing luminance unevenness between the central region and the peripheral region in the image in the direction and allowing the observer to view a high quality image.

Abstract: A virtual image display device includes a display light guiding unit, and an image forming unit that emits image light to the display light guiding unit, the display light guiding unit includes a first light guiding unit that guides image light corresponding to a first angle of view, and a second light guiding unit that guides image light corresponding to a second angle of view, among angles of view of image light emitted from the image forming unit, and the first light guiding unit and the second light guiding unit respectively include incident side diffraction elements that take the image light beams into the inside, and emission side diffraction elements that emit the image light beams to the outside.

Abstract: A rechargeable battery protection circuit protects a rechargeable battery, using two NMOS transistors inserted in series in a current path between a battery cathode and a positive terminal connected to load or power terminal of a charger. The protection circuit includes a booster circuit that generates a control voltage, using input capacitances of the NMOS transistors having gates connected to charge and discharge control terminals, respectively. A driving circuit sets the output state of the control terminals to a high level, by supplying the control voltage to the control terminals, a detection circuit detects a battery state and outputs a detection state, and a control circuit operates the driving circuit based on the detection state, so that the output state of the control terminals is selected by the driving circuit to at least one of three states including a high level, a low level, and a high-impedance state.