Abstract:
A method of reducing electromagnetic waves radiated from a cable receiving opening of an electronic device, that easily improves the electromagnetic wave shielding effect, regardless of the number of cables, and facilitates cable connection/disconnection. A soft electromagnetic shielding conductive cloth (15) is provided to cover completely the opening (12). The opening (12) is formed in the cabinet (11a) to connect the cables (14) to terminals of the device body (11). The conductive cloth (15) is attached to the opening (12) and electrically connected to the shielded cabinet (11a) in such a way that the conductive cloth (15) deforms to open/close the opening (12). The conductive cloth (15) has plural vertical slits (15a) through which the cables (14) can pass. The lower side of the cloth (15) is not fixed. A plurality of conductive cloths (15) may be superposed. The lower open end may be vertically long enough to wrap the cable (14).
Abstract:
A delay time control circuit controls delay times without a significant increase of power consumption or circuit components. The delay time control circuit for controlling delay times in a logic circuit (13) includes a delay circuit (10) having a plurality of serially connected gates, a pulse signal (A1) supplied to the delay circuit; a first group of gates (11) which generates a reset pulse based on the pulse signal, a second group of gates (12) which generates a set pulse based on the pulse signal, a delay-duty converter (14) which is driven by the set and reset pulses, an integrator (15) which integrates an output signal of the delay-duty converter to produce an average voltage indicating a duty cycle of the output signal, a first delay time control voltage generator (16) which compares the average voltage and a reference voltage (17) indicating a delay time for the logic circuit and generates a first control voltage which is applied to the logic circuit, and a second delay time control voltage generator (18) which receives the first control voltage and generates a second control voltage which is symmetrical to the first control voltage and is applied to the logic circuit.
Abstract:
An optical fiber buried layer in which an optical fiber is buried is provided in part of the layers of an electrical wiring board constituting a mother board on which an electric circuit is mounted. A hole is made in the surface of the buried layer to expose one end of the buried optical fiber. A reflective face having a 45 DEG inclination is provided on the exposed end of the optical fiber to reflect light to be emitted from the optical fiber in a direction perpendicular to the board plane of the wiring board. The reflected light enters the end face of an optical fiber of a daughter board. Light emitted from the optical fiber end face of the daughter board is reflected by the 45 DEG reflective face and enters the optical fiber in the buried layer.
Abstract:
The circuit construction of a memory tester having a mask pattern memory is simplified. Mask pattern data read out of the mask pattern memory (11) are, without being converted into a bit arrangement corresponding to the arrangement of the terminals of a memory (200) under test, supplied directly to a masking circuit (113). Provisional fail data of the bit arrangement are given from a logic comparator (107) to a fail data selector (108) which controls the flow of the fail data whose arrangement is converted into a bit arrangement in order of weighting and supplies the fail data to the masking circuit, by which the writing into a defect analysis memory (109) is masked.
Abstract:
This detector is provided with a suction transfer arm (12) for vacuum sucking an object material (11) at a nozzle bore and transferring the material in the horizontal and vertical directions. On the rear side of the portion of a stage (13) on which the material (11) to be sucked is placed, an upwardly directed light-emitting sensor (14) is provided. The portion of the stage on which the material (11) to be sucked is placed is provided with a through hole by which the upward rays of light-emitting sensor (14) is not shut off. At an inner part of the nozzle bore of the suction transfer arm (12), a downwardly directed light receiving sensor (15) for receiving the rays of light from the light-emitting sensor (14) is provided.
Abstract:
A semiconductor package (11) has a substrate (12) which is mounted with a semiconductor chip on one surface and numerous external terminals (14) arranged at prescribed pitches on the other surface. Positioning holes (13) are formed at two or more desired locations of the substrate (12) so as to ensure the dimensional accuracy between the holes and one arbitrary external terminal (14a).
Abstract:
A semiconductor testing device with a rewrite controller, having a function to conduct simultaneous measurement of a rewritable semiconductor memory such as a flash memory, and capable of controlling rewrite of one page at a time thereby to shorten the testing time. The semiconductor testing device is provided with a holding means (5) which detects fail information during the rewrite of one page from the output signal of an inspecting circuit (1) and holds the information, judging means (11) which judges whether or not any of the devices to be measured fails when one page rewrite is completed, and a rewrite control section (100) which outputs the output signal of the judging means or flip-flop (11) as a rewrite inhibiting signal (102). A plurality of such rewrite control sections (100, 200, 300) may be provided depending on the number of devices.
Abstract:
A memory tester which judges quickly whether or not a faulty IC memory can be repaired. A fail cell (1) receives a fail signal from a logic comparator (14) and an address signal for receiving a fail signal from a pattern generator (23) and stores only the faulty address of the IC memory, and is constituted of an address holding register (3), an address comparator (5), and a controller (8). Using a fail cell array (2) in which a plurality of fail cells are cascade-connected, only fail addresses among the data used for making a fail map are stored. Consequently the time taken to read the fail addresses from the fail cell array and to send them to an operation section (15) is shortened.
Abstract:
A semiconductor tester which fetches a clock signal generated from a device to be tested, stabilizes the clock signal by removing jitter components, and uses the stabilized clock signal to operate the device. The tester includes a frequency divider A (11) which receives the clock signal (21) from the device to be tested, a phase detecting circuit (12), a loop filter (13), a VCO (14), a frequency divider B (16), a test period generator (15), and an interleave circuit (18). The clock signal outputted from the VCO (14) is inputted to the test period generator (15) to produce a test period signal (23), which is distributed to internal circuits of the device and, at the same time, is fed back to the phase detector (12) through the frequency divider B (16).
Abstract:
Radio waves having frequencies of f1 and f2 are radiated in an area where a wireless LAN is to be set up, the radio waves f1 and f2 are separately received with an antenna which scans the surface to be observed and a fixed antenna, and their radio wave holograms are produced. Then radio wave images separated for each path are formed from the holograms, and the amplitude and delay of each path are found by finding the difference between the radio wave images. The propagation time response function x(t) of each path is found from the amplitude, delay, and the directional characteristics of the antennas and the real part and imaginary part of the function are convoluted in a modulated carrier signal y(t). Then the real and imaginary parts are respectively multiplied by the in-phase component Rf and the orthogonal component Rf* of a non-modulated carrier. Finally, a demodulated base-band signal gamma (t) is obtained by adding both products to each other. The radio wave time lag of each secondary radio wave image with respect to a primary radio wave source is found and the radio wave images are rearranged in an absolute three-dimensional coordinate system by using the time lags. Then the intensity of the radio waves at an arbitrary position in the absolute coordinate system is found by combining radio waves from each radio wave image and the mean value and standard deviation of the delays are found from the time lags and intensity attenuation corresponding to the distance to each radio wave image.