Abstract:
Provided are a thickness measuring apparatus and a thickness measuring method. The thickness measuring method includes irradiating first laser beam of a first wavelength λ1 to a transparent substrate and measuring intensity of first laser beam transmitting the transparent substrate; irradiating second laser beam of a second wavelength λ2 to the transparent substrate and measuring intensity of second laser beam transmitting the transparent substrate; and extracting a rotation angle on a Lissajous graph using the first and second laser beams transmitting the transparent substrate. A phase difference between adjacent rays by multiple internal reflection of the first laser beam and a phase difference between adjacent ray by multiple internal reflection of the second laser beam is maintained at π/2.
Abstract:
Provided are a transparent substrate monitoring apparatus and a transparent substrate monitoring method. The transparent substrate monitoring apparatus includes a light emitting unit emitting light; a double slit disposed on a plane defined in a first direction and a second direction intersecting a propagation direction of incident light and includes a first slit and a second slit spaced apart from each other in the first direction to allow the light to pass therethrough; an optical detection unit measuring an intensity profile or position of an interference pattern formed on a screen plane; and a signal processing unit receiving a signal from the optical detection unit to calculate an optical phase difference or an optical path difference.
Abstract:
Provided is an absolute position color scale disposed to represent a binary code using a first symbol, having a first width and representing a first state (“HIGH”), and a second symbol having the first width and representing a second state (“LOW”). Each of the first and second symbols is divided into two or more segments having the same structure, and the first symbol has the same shape as the second symbol, but has a color pattern different from a color pattern of the symbol.
Abstract:
A distance measuring apparatus includes an image sensor and an image sensor driver. The image sensor includes a photodiode, a first capacitor and a second capacitor, and a first transfer gate and a second transfer gate configured to transmit an output of the photodiode to the respective first and second capacitors. The image sensor driver is configured to complementarily drive the first transfer gate and the second transfer gate.