An electrochemical cell includes a solid electrolyte layer and a first electrode. The solid electrolyte layer includes a first material having ion conductivity and in which a rare earth element is contained as a solid solution. The first electrode contains...

A virtual image display device includes a backlight, a display panel, an optical system, and a backlight controller. The backlight includes a plurality of light emitters and a light-emitting surface that can emit light from the plurality of light emitters....

To realize easy checking of a connection state. A receiving portion is located on a frame portion or an insulation substrate, and a conductive metal plate is located on an opening side of a recessed portion. The conductive metal plate includes a connecting...