Abstract: A chromatic dispersion distribution measurement apparatus, comprises: an output light intensity measurement unit for measuring an intensity of an output light outputted from an optical device to be measured; and an input light intensity control unit for automatically controlling an intensity of an input light to be inputted into the optical device to be measured, in accordance with the intensity of the output light, which is measured by the light intensity measurement unit.

Abstract: A laser diode 11 and a lens 12 for focusing the rays of oscillated light from it are arranged such that the central axis 14 of the former aligns with the optical axis 15 of the latter. In addition, the lens 12 and the multi-mode optical fiber 13 into which the focused light beam is launched are coupled and fixed in such a way that the central axis 16 of the multi-mode optical fiber 13 is offset by a predetermined length in a direction normal to the axis of said alignment.

Abstract: A power supply which can individually limit the discharge current and the absorbing current as the output current supplied to the load is disclosed. The power supply comprises an amplification circuit for amplifying and supplying an analog voltage value to the load; a limited current switching circuit, connected to a current limiting control terminal of the amplification circuit, for changing the amount of a limited current which controls the output current of the amplification circuit; and a switching control circuit for outputting a switching signal by which the limited current switching circuit changes the amount of the limited current.

Abstract: Extension boards and a method of extending boards capable of reducing a fabrication cost and capable of mounting electronic devices on a board with high density which board is mounted onto an electronic equipment from the beginning. In a memory board on which connectors and electronic devices are mounted, each connector is formed of an upper connector and a lower connector, and signal lines extend in the memory board, wherein terminals or connector pins of the upper and lower connectors form one pair in appearance while interposing the memory board therebetween, and each pair forms a terminal group.

Abstract: A pattern generator repetitively supplies the same test pattern to a DUT via a driver, and a signal converter converts the obtained source current value into a digital signal that it transmits to an averaging processor. Thereafter, the averaging processor adds together source current signals corresponding to the test patterns for each application and obtains an average for them. Then, a signal analyzer converts the averaged current signal, from which fluctuation has been eliminated, into a spectrum that, to detect failure, a comparison determination circuit compares with comparison data stored in a memory. For this process, a plurality of like test patterns are linked together and supplied to a DUT, and a source current signal is generated by using the linked patterns and is converted into a spectrum that is employed to detect a failure.

Abstract: A wavelength measuring apparatus capable of obtaining two signals by a single etalon, and which is physically stable and has high resolution so that direction to which wavelength varies can be recognized in wideband is provided. A Fabry-Perot etalon (etalon) is serves as a wavelength discriminating section of a wavelength measuring apparatus. A beam from an optical fiber passes through a lens generating a collimated beam. An optical branching section splits the collimated beam into two beams and inputs the two beams to the etalon. An optical axis of one split collimated beam is tilted with regard to an optical axis of another one such that each period of amplitude of the split collimated beams relatively shifts in &pgr;/2 phase difference. Each first and second photo detectors receives each split collimated beam which has transmitted the etalon, and detects a signal depending on the wavelength.

Abstract: A Fabry-Perot etalon comprises two faces having a reflecting film. A beam is transmitted through the Fabry-Perot etalon and split into two. One face is inclined to the other so that each of the two beams will relatively shift in a phase difference of &pgr;/2. The Fabry-Perot etalon is used as a wavelength discrimination unit. The beam transmitted through the Fabry-Perot etalon is branched off by a knife-edged mirror and reflected therein. The branched beams are received by first and second PDs, respectively, and signals which depend on wavelength are detected.

Abstract: An autohandler for continuously processing devices for a shorter total processing time, for every device. The autohandler comprises: a loader (11) in which a tray (2) including devices which have not been tested is loaded; a sending shuttle (12) for transferring the tray to a test preparative position (P1); a test stage (20) for holding the tray on the sending shuttle waiting at the test preparative position, transferring the devices kept included in the tray to a test section in order, and transferring the tray to a receiving preparative position (P2); a receiving shuttle (13) for receiving the tray from the test stage at the receiving preparative position, and transferring the tray to a receiving buffer (P3); and a sorting section for sorting the devices in the tray on the receiving shuttle, on the basis of results of the test carried out by the test section.

Abstract: An autohandler for transporting a carrier which accommodates a plurality of electronic parts therein, to a test section to test electrical characteristics of the electronic parts. The autohandler comprises: a preheating section for heating or cooling the electronic parts to be tested, to a predetermined temperature; a test section for measuring electrical characteristics of the electronic parts which are heated or cooled, by electrically connecting each of the electronic parts to a testing device; a dry chamber for returning the temperature of tested electronic parts back to a normal temperature to prevent from generation of frost caused by a low temperature in the test section, and a part detecting section provided between the test section and dry chamber, for detecting whether each electronic part tested in the test section exists on a predetermined position for each electronic part to be accommodated, of the carrier.

Abstract: An electro-optic probe is provided which is able to prevent unnecessary reflected light from optical components in the electro-optic probe from entering photodiodes. The optical components which constitutes an isolator 13 are disposed inclining from an optical path of a parallel light emitted from a collimating lens 8, such that the unnecessary reflected light beams from these optical component surfaces are not incident to the photodiodes 10 and 11. The inclination angle of these optical components are set within a range from an angle formed by an optical path from said optical component to a light receiving element in said photodiode, and the diameter of said light receiving element to an angle allowable for the optical component to maintain the transmittance thereof.

Abstract: A pattern data transfer circuit capable of decreasing the number of transfer of pattern data and of shortening the entire transfer time as a whole. A chip selector circuit generates pin group data representing tester channels contained in respective pin groups on the basis of pin groups such as “ADDRESS” and adapter board data corresponding to the tester channels, and it validates only a chip select signal corresponding to the tester channel shown by the pin group data in the case of transfer of “I/O” data and “Strobe Mask” data, and also validated either chip selector signal CS corresponding to the tester channel in the case of transfer of “HiLo” data. A CPU extracts respective patterns of the selected pin group from pattern data and transfers the extracted patterns to all the pattern memories.

Abstract: A probe for an electro-optic sampling oscilloscope is provided, capable of obtaining an improved accuracy in measurement of the test measuring signals by controlling a temperature of an electro-optic element so as to be maintained at a constant such that the refractive index of the electro-optic element does not change due to the temperature change. The probe for the electro-optic sampling oscilloscope comprises a reflecting film at one end and a metal pin provided on the surface of the reflecting film such that the optical property of the electro-optic film changes according to an electric field applied through the metal pin.

Abstract: An external cavity type light source which has a semiconductor laser (1) coated on one end (1a) with a reflection prevention film (1A), wherein emitted light from the end face of the semiconductor laser 1 on the reflection prevention film side is converted into collimated light and the collimated light having a wavelength selected through a diffraction grating (2) is fed back into the semiconductor laser (1), and wherein emitted light from an opposite end (1b) of the semiconductor laser (1) is converted into collimated light and the collimated light is gathered and output to an optical fiber (10). An unpolarized light splitter (light branch element) (4) is placed between the diffraction grating (2) and the semiconductor laser (1), and the diffracted light fed back into the semiconductor laser from the diffraction grating is made to branch through the unpolarized light splitter (4) and one branch light is taken out as output light through an optical fiber (15).

Abstract: The present invention provides a positioning apparatus in which the correction of discordance between the probe card and TAB can be performed easily and quickly. The positioning apparatus of the present invention comprises a probe card, TAB, arithmetic processing unit, and an automatic XY-moving mechanism. In the positioning apparatus, coordinates which denote a position of an optionally selected probe of the probe card and a position of a test pad of the TAB in which the probe is expected to make contact are entered into the arithmetic processing unit. The arithmetic processing unit automatically calculates corrective distances for contacting the test pad and probe, and outputs a signal corresponding to the corrective distances to the automatic XY-moving mechanism. The automatic XY-moving mechanism automatically moves the probe card toward the TAB in proportion to the corrective distances.

Abstract: An electro-optic sampling probe for preventing noise from being transmitted to photodiodes and improving the measurement accuracy is disclosed. In the probe, the optical system module comprises wavelength plates and polarized beam splitters arranged along an optical path of the relevant laser beam, and photodiodes facing the polarized beam splitters, wherein each photodiode is fixed via an insulating material to the main frame of the optical system module.

Abstract: A bit error measuring device for modem device, comprises; a bit error measuring unit for measuring a bit error in an input signal from the modem device, a clock controlling unit for controlling an output of a clock signal on the basis of a control signal outputted from the modem device, and a test pattern transmitting unit for transmitting a test pattern signal by synchronizing with the clock signal when clock pulses of the clock signal are outputted from the clock controlling unit, and for stopping a transmission of the test pattern signal when the clock pulses of the clock signal are not outputted from the clock controlling unit.

Abstract: A carrier transporting apparatus comprises a thermostat for testing devices loaded on a carrier, and the carrier is carried out from the thermostat through an opening formed in the thermostat. A shutter is provided for opening and closing the opening, and a carrier guide is integrated with the shutter. As the shutter is opened for carrying out the carrier from the test section, the carrier guide is moved to a waiting position where the carrier guide does not obstruct the carrier. As the shutter is closed after the carrier is carried out, the carrier guide is moved to a guiding position where the carrier guide guides the carrier in a direction to cross the direction in which the carrier is carried out from the thermostat. Thereafter, the carrier guide guides the carrier so that the carrier is transported in the cross direction.

Abstract: A CRC encoding circuit for generating a CRC code in accordance with a parallel data having a remainder portion data in a last data set of the parallel data, comprises: a first encoding unit for generating one or more first CRC codes in parallel in accordance with the remainder portion data; a CRC code selecting unit for selecting a second CRC code having predetermined number of bytes, from the first CRC codes generated by the first encoding unit; a converting unit for converting the remainder portion data into a serial data; and a second encoding unit for generating a third CRC code in accordance with the second CRC code selected by the CRC code selecting unit and the serial data converted by the converting unit.

Abstract: A low coherent reflectometer uses low coherent beams for measurement of reflectance and reflecting positions with respect to a measured optical circuit which includes a reflecting point. The low coherent beams are branched to produce measurement beams (DL) and local beams (KL), so that the measurement beams are introduced into a first optical path, which includes a dispersion shifted fiber, towards the measured optical circuit, while the local beams are introduced into a second optical path which includes a spatial optical path terminated by a reflecting mirror. Reflected measurement beams (RL) and reflected local beams are combined together to produce combined beams, which are subjected to processing and analysis. The spatial resolution is noticeably improved even though the spatial optical path length is varied because the length of the dispersion shifted fiber is determined to substantially match the spatial optical path length.

Abstract: Data other than inserted “0”'s are selected by first selectors from among a plurality of data included in input data to which zero value interpolation is carried out at an interpolation circuit. Besides, coefficients by which the data selected by the first selectors should be multiplied are selected by second selectors. The data selected by the first selectors are multiplied by the coefficients selected by second selectors in multiplication circuits. Then, an adding circuit adds all of the multiplied results and outputs the added result as the desired filter characteristic.