Korea Research Institute of Standards and Science

Jae-Wan Kim

Jong-Ahn Kim

Chu-Shik Kang

Jae-Yong Lee

Tae-Bong Eom

Jae-Heun Woo

Jong-Han Jin

Young Pyo Hong

Jonghan Jin

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.

Distance measuring apparatus and method of operating the same

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.

Absolute position measuring method, absolute position measuring apparatus, and colour scale comprising plural symbols each with plural segments of different color patterns

A thickness measuring apparatus and a thickness measuring method. The thickness measuring apparatus includes a light source outputting an extended monochromatic light with coherence; a collimating lens converting output light of the light source into incident beam of parallel ray; a beam splitter reflecting and providing the incident beam to a measurement target and transmitting first reflection light reflected on a top surface of the measurement target and second reflection light reflected on a bottom surface of the measurement target; an imaging lens disposed between the measurement target and the beam splitter with a predetermined focal distance to receive and provide the incident beam to a measurement position of the measurement target disposed on the focal distance; a camera photographing an interference fringe formed by the first and second reflection lights and outputting an interference fringe image; and a processing part.

Thickness measuring apparatus and thickness measuring method

Provided are a thickness measuring apparatus and a thickness measuring method. The thickness measuring method includes irradiating a first laser beam of a first wavelength &#x3bb;to a transparent substrate and measuring intensity of the first laser beam transmitting through the transparent substrate; irradiating a second laser beam of a second wavelength &#x3bb;to the transparent substrate and measuring intensity of the second laser beam transmitting through the transparent substrate; and extracting a rotation angle on a Lissajous graph using the first and second laser beams transmitting through the transparent substrate. A phase difference between adjacent rays by multiple internal reflection of the first laser beam and a phase difference between adjacent rays by multiple internal reflection of the second laser beam is maintained at &#x3c0;/2.

Provided are an absolute position measurement method, an absolute position measurement apparatus, and a scale. The scale includes a scale pattern formed by replacing repeatedly arranged pseudo-random-codes with a sequence of a linear feedback shift register of N stages using a first symbol with first width representing a first state and a second symbol with second width representing a second state. The first is divided into two or more first symbol areas of different structures, and the second symbol is divided into two or more second symbol areas of different structures. There is at least one overlap area in which the first symbol and the second symbol overlap each other to have the same structure.

Absolute position measurement method, absolute position measurement apparatus and scale

A frequency-stabilized laser apparatus and a method for stabilizing the frequency of a laser are disclosed. A semiconductor laser emits a beam. An external reflector has a resonance frequency and feeds back the emitted beam to the semiconductor laser if the frequency of the emitted beam is equal to the resonance frequency. An interference signal generator generates an interference signal for detecting the wavelength of the emitted beam and a controller detects the wavelength of the beam from the generated interference signal. According to the frequency-stabilized laser apparatus and the method for stabilizing the frequency of the laser, it is possible to stabilize the frequency of the beam emitted from the semiconductor laser and output the beam having the stable frequency for a long period of time.

Apparatus and method for stabilizing frequency of laser

A shape measurement apparatus and method using a laser interferometer are disclosed. The shape measurement apparatus includes a plurality of laser devices, which generate beams, emit a beam of a specific frequency from among the generated beams, and output interference signals for detecting wavelengths of the generated beams, and a controller for detecting the wavelengths of the generated beams from the outputted interference signals, and controlling the laser devices on the basis of the detected wavelengths. The optical unit projects the beam of the laser device on a target object, and generates an interference pattern of the object. Several shutters are closed and opened. If the shutters are closed, they prevent the beam of each laser device to be projected on the optical unit. An image pickup unit captures the interference pattern.

Growing community of inventors

Daejeon, South Korea

Jae-Wan Kim