Abstract: A compact card type disk drive includes a housing (21) for accommodating a disk for storing data, disk drive for rotating the disk, a head assembly for writing and reading data to and from the disk and an electronic circuit including at least an interface circuit (39), the latter three being accommodated in the housing. A connector (42) connected to the electronic circuit is fixed to the outside portion of the housing (21). The electronic circuit preferably contains a read/write circuit (36) and a control circuit (38). The housing (21) preferably includes a lower base (22) and an upper cover (23), and a printed circuit board (14) is disposed along the inner wall of either one, or both, of the base (22) and the cover (23). The outer dimension of the plane of the disk drive is preferably about 85.6 mm.times.54 mm, and typically, the outer thickness is 5 mm. Preferably, one connector (42) is disposed on either one of the minor sides of the housing (21).

Abstract: Disclosed are an asymmetrical signal detector for detecting an asymmetrical quantity of an asymmetrical signal and a signal regenerating apparatus using this detector. This detector includes a first delaying element for delaying the input signal, a first subtracting element for subtracting an output of the first delaying element from the input signal, a second delaying element for delaying an output of the first subtracting element, an adding element for adding an output of the second delaying element to an output of the first subtracting element, a gate signal generating element for generating a gate signal by comparing an output of the adding element with a predetermined threshold value, a second subtracting element for subtracting the output of the subtracting element from the input signal and a selecting element for selecting an output of the second subtracting element in accordance with the gate signal, thereby obtaining an offset quantity.

Abstract: A medical photographic instrument includes a medical photographic portion and an electronic image recording portion. The medical photographic portion includes a monitor for displaying an observation image for alignment and a record image recorded in the electronic image recording portion and a display selecting circuit for making an alternate change between the observation image and the record image displayed on the monitor. The electronic image recording portion includes an operation changing circuit for making an alternate change between a recordable state and an image recording state according to a signal output by the medical photographic portion and a strobe synchronous circuit for outputting a strobe synchronizing signal according to which a strobe emits a flash of light when the recordable state is changed to the image recording state.

Abstract: A retracting assembly produces a constant torque, in a data zone of a magnetic disk, which is greater than static friction of a bearing for a rotary actuator. However, in a parking zone on an outer portion of the magnetic disk, the retracting assembly generates a torque which suddenly increases so that a large holding torque is obtained and a magnetic head is reliably locked.

Abstract: A maximum-likelihood decoding method for decoding an input signal subject to intersymbol interference. An assumption is made of a measure of an interference caused by a future signal that is later in a sequence than an assumed data sequence, on the basis of a predetermined bits of sample values of said input signal that are earlier in a sequence than an assumed data sequence stored in an assumed path memory (104). An assumed sample value of said input signal by referring to this measure of interference. Maximum-likelihood decoding is conducted on said input signal, on the basis of this assumed sample value and a sample value of said input signal; a plurality of survivor paths are generated and stored in a path memory (102); data for the most likely one of survivor paths is output as a decoded data sequence.

Abstract: A Viterbi decoding system includes a characteristic estimator for estimating a characteristic of a system, and an equalizer for receiving an input signal from the system and for equalizing a waveform of the input signal so that an equalized waveform of the input signal is varied based on the characteristic of the system estimated by the characteristic estimator. A Viterbi decoder generates an output signal showing a maximum-likelihood path by using the equalized waveform of the input signal from the equalizer.

Abstract: A substrate for high-frequency circuits best suited as a substrate for a flat antenna to receive satellite-broadcast microwaves or as a similar substrate, the substrate comprising (i) a porous insulator layer wherein the proportion by volume of open cells to all the cells is at least 50% and (ii) a metal foil laminated over at least one side of the insulator layer through (iii) a water-impermeable film, and a process for making such substrates.