Light redirection in optical navigation

摘要

An optical navigation device, such as an optical navigation joystick or mouse, includes an internal redirector which may be separate or formed from material of a touch surface of the optical device. The redirector is disposed at an angle with respect to a plane of the touch surface, operative to reflect light which would otherwise strike the touch surface at a low angle and be internally reflected. The light may be reflected in a direction away from a light sensor of the device, reducing sensed internally reflected light, or may be reflected into the touch surface at a higher angle, potentially increasing a quantity of good signal. The redirector may also include portions which block light directly emitted from a light emitter, or reflected off other surfaces of the navigation device.

主权项

1. A navigation device, comprising:
a light emitter disposed within an interior of the navigation device; a light transmitting touch surface having an upper side and a lower side that is opposite the upper side and separated from the upper side, a sensor disposed within the interior of the navigation device and operative to sense light emitted from the light emitter that has reflected into the interior of the navigation device from an object in contact with the upper side; and a redirector sized and positioned within the interior of the navigation device to
obstruct light emitted from the light emitter that is directed at the lower side at a lower angle of approximately 0-45 degrees with respect to the lower side, thereby decreasing an amount of light reflected from the lower side to the interior; andpass light emitted from the light emitter that is directed at the lower side at a higher angle of approximately 45-90 degrees with respect to the lower side, thereby allowing light to pass through unobstructed to the upper side.