Abstract: A mobile phone assembly for magnifying a portion of a surface. The assembly includes: a mobile phone having a display screen and a camera with an image sensor; and an optical assembly including: a first mirror offset from the image sensor for deflecting an optical path substantially parallel with the surface; a second mirror aligned with the camera for deflecting the optical path perpendicular to the surface and onto the image sensor; and a microscope lens positioned in the optical path. The optical assembly has a thickness of less than 8mm and is configured such that the surface is in focus when the mobile phone assembly lies flat against the surface.

Abstract: A microscope accessory for attachment to a mobile phone having a display positioned in a first face and a camera positioned in an opposite second face. The microscope accessory includes: engagement features for releasably attaching the microscope accessory to the mobile phone; and an optical assembly having: a first mirror positioned to be offset from the camera; a second mirror positioned for alignment with the camera; and a microscope lens positioned in the optical path. The optical assembly is matched with the camera, such that a surface is in focus when the mobile phone lies flat against the surface.

Abstract: A handheld display device having a substantially planar configuration. The device includes: a housing having first and second opposite faces; a display screen disposed in the first face; a camera having an image sensor positioned for receiving images from the second face; a window defined in the second face, the window being offset from the image sensor; and microscope optics defining an optical path between the window and the image sensor. The microscope optics are configured for magnifying a portion of a surface upon which the device is resting. A majority of the optical path is parallel with a plane of the device.

Abstract: A method is described for positioning an image sensor at a point of best focus for a lens. The lens has an optical axis and the image sensor is moved to a plurality of positions along the optical axis. The image sensor captures an image of a target image at each of the plurality of positions through the lens. A measure of blur in the image captured is derived at each of the plurality of positions from pixel data output from the image sensor. A relationship is derived between blur and position of the image sensor along the optical axis. The image sensor is then moved to a position on the optical axis that the relationship indicates as the point of best focus where the image sensor is fixedly secured relative to the lens.