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.

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: 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.

Abstract: 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.

Abstract: 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 ?1 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 ?2 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 ?/2.

Abstract: 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.

Abstract: 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.

Abstract: The present invention pertains to a device and a method for measuring a via hole of a silicon wafer, wherein it is possible to precisely measure the depth of the via hole without damaging the wafer. Broadband infrared light is radiated to a silicon wafer which has a superior light transmission property, so that the depth of the via hole may be measured from the light which is reflected from each boundary surface of the wafer and the interference signal of reference light. The via hole measuring device according to the present invention includes: a light source unit for generating broadband infrared light; and an interferometer for radiating the light generated from the light source unit to a silicon wafer, so as to measure the depth of a via hole formed on the wafer according to the spectrum period of the interference signal of the light, which is reflected from the silicon wafer.

Abstract: Provided is a spatial phase shifting interferometer using a multi wavelength. More particularly, provided is a spatial phase shifting interferometer using a multi wavelength capable of more rapidly measuring a precise shape of a measurement object by simultaneously oscillating laser having different wavelengths and passing the oscillated laser through a beam splitter and a lens to analyze an interference fringe of the measurement object.

Abstract: 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.

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 are a thickness measuring apparatus and a thickness measuring method. The thickness measuring method includes irradiating first laser beam of a first wavelength ?1 to a transparent substrate and measuring intensity of first laser beam transmitting the transparent substrate; irradiating second laser beam of a second wavelength ?2 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 ?/2.

Abstract: The present invention pertains to a device and a method for measuring a via hole of a silicon wafer, wherein it is possible to precisely measure the depth of the via hole without damaging the wafer. Broadband infrared light is radiated to a silicon wafer which has a superior light transmission property, so that the depth of the via hole may be measured from the light which is reflected from each boundary surface of the wafer and the interference signal of reference light. The via hole measuring device according to the present invention includes: a light source unit for generating broadband infrared light; and an interferometer for radiating the light generated from the light source unit to a silicon wafer, so as to measure the depth of a via hole formed on the wafer according to the spectrum period of the interference signal of the light, which is reflected from the silicon wafer.

Abstract: Provided is a spatial phase shifting interferometer using a multi wavelength. More particularly, provided is a spatial phase shifting interferometer using a multi wavelength capable of more rapidly measuring a precise shape of a measurement object by simultaneously oscillating laser having different wavelengths and passing oscillated laser through a beam splitter and a lens to analyze an interference fringe of the measurement object.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A tape format of 4-mm wide video tape for use in a video tape recorder adopting helical scanning and azimuth recording methods is disclosed in conjunction with a video tape recorder system thereof, which enables the video tape recorder to achieve the greatest size-reduction and improve the resolution in picture reproducing by raising the S/N ratio of video signals. The tape format includes a video width area for an automatic track finding signal to control the traveling of tape and the video signal consisting of color signals and luminance signals, an option track area for recording audio signals, a first guide area for keeping the minimum part of tape in touch with the upper drum, a second guide area for separating the audio signals of the option track area from the video signals of the video width area, and first and second overlap areas respectively below the first guide area and above the second guide area, provided for overlapping the video signals on the edges of video tracks in recording operation.