Autofocus system and autofocus method

摘要

An embodiment of an autofocus system is provided, including a height detection module, an image detection module, a movement unit and a processing unit. The height detection module is arranged to output a plurality of detection lights along a Z axis direction, wherein each of the detection lights has different focal lengths and different wavelengths such that the height detection module generates a dispersion region along the Z axis direction. The image detection module is arranged to capture an image of the focus position. The movement unit is arranged to move an object along the Z axis direction, wherein the object has an internal surface and an external surface. The processing unit determines whether the external surface and the internal surface are within the dispersion region according to the quantity of the energy peaks of a reflectance spectrum received by the height detection module.

主权项

1. An autofocus system, comprising:
a height detection module, arranged to output a plurality of detection lights along a Z axis direction, wherein each of the detection lights has different focal lengths and different wavelengths, such that the height detection module generates a dispersion region along the Z axis direction; an image detection module, arranged to capture an image of a focus position; a movement unit, arranged to move an object along the Z axis direction, wherein the object has an internal surface and an external surface; and a processing unit, arranged to determine whether the external surface and the internal surface are within the dispersion region according to a quantity of the energy peaks of a reflectance spectrum received by the height detection module, such that the processing unit calculates an actual distance between the internal surface and the focus position when the external surface and the internal surface are within the dispersion region, thereby the processing unit moves the internal surface to the focus position by the movement unit in accordance with the actual distance.