External device and mounting structure for mounting to electronic device

A projector-and-mounting structure for an electronic device having a front face with a display screen thereon, a rear face opposite to the front face, wherein the rear face has a light emitting element thereon, and an edge between the front and rear faces, comprising:

• a projector body having an aperture therethrough, an inside face defining a light inlet to the aperture, and an outside face defining a light outlet from the aperture, wherein the projector further includes a slot positioned to hold a slide transparency in the aperture for transmission of light therethrough, wherein the projector further includes a magnifying lens aligned with the aperture and positioned to enlarge an image on the slide transparency for projection through the light outlet;
• and
• a mounting structure that engages the front face and the rear face of the electronic device and which holds the projector in engagement with the rear face with the light inlet in alignment with the light emitting element,
• wherein the mounting structure has a limit surface that is engageable with the edge of the electronic device to determine a reach of the aperture on the rear face of the electronic device,
• wherein the limit surface is positioned such that, for a first type of electronic device in which the light-emitting element is positioned at a first distance from the edge, the mounting aperture is mountable to the first type of electronic device with the aperture aligned with the light-emitting element on the rear face such that the limit surface is spaced from the edge,
• and for a second type of electronic device in which the light-emitting element is positioned at a second distance from the edge that is different than the first distance, the mounting aperture is mountable to the second type of electronic device with the aperture aligned with the light-emitting element on the rear face of the second type of electronic device.