非接觸Point sensor感應器種類 a.雷射三角形:Laser Triangulation b.動態聚焦型:Dynamic Focusing c. Conoscopy d.色彩共焦: Chromatic Confocal a.雷射三角形:Laser Triangulation • This type of sensor uses a laser that projects a spot on the surface to be measured. The position of the spot on the surface is located by a detector on one side at a specific angle. The altitude is derived from knowledge of the parallax between the laser and the point of observation. 優點: *量測範圍大,從幾十um到幾十mm. h 缺點: *易受陰影及試片表面透明度的影響. *雷射點太大 ,易干擾量測結果 b.動態聚焦型:Dynamic Focusing • h This sensor uses a laser to project a spot on the surface to be measured. The objective is displaced in real time to guarantee that the spot is focused on the surface. The altitude signal is deduced from the control signal that displaces the objective. 優點:高解析度,同步光學系統 缺點:量測速度慢 c.Conoscopy • This type of sensor uses a laser that projects a spot on the surface to be measured. The reflected light is sent back to a detector via a birefringence crystal which modifies the speed of the wave in proportion to its angle of diffusion, which is itself proportional to the distance of the object with respect to the source. This creates interferences on the detector which are analysed in order to derive the distance of the object. 優點: 可以量測非常高傾斜的試片 缺點: 解析度不高,無法量測粗糙度 d.色彩共焦:Confocal Chromatic • This type of sensor uses a source of white light that projects a light beam on the surface through a chromatic objective, dispersing the wavelengths along the optical axis. The altitude of the surface point is located by a spectrometer which determines what wavelength is focused on the surface. 優點: 高垂直解析度. 可以量測透明的玻璃及薄膜. 高量測速度. 缺點: 在反射的材料上對陡坡比較 敏感.