Abstract: The conventional speakerphone using the voice switch, when combined with the echo canceler, involves a problem that the threshold for switching the transmit/receive state of the voice switch cannot comply smoothly and stably with the performance variation of the echo canceler, thereby obstructing echo canceling in a manner that the voice switch cooperates with the echo canceler. The speakerphone of the invention estimates the performance variation of the adaptive filter by using the integrated value of a power of the receive signal or the transmit signal referred in the past when the adaptive filter learns, and varies the threshold in accordance with the performance variation. Thus, the speakerphone of the invention achieves a stable communication system that approaches to the fill duplex with the voice switching system and the echo canceling system combined.

Abstract: A digital information reproduction apparatus for compressing frames of data so as to intermittently reproduce the data in fast-forward speed. A data re-write device retrieves a reproduction-target frame for the fast-forward reproduction and a parameter-calculation-target frame exclusively for calculation of the frame data parameters. The frames then are transferred to a RAM. A decoder determines the frame data in the RAM, calculates the parameter-calculation frame data, and decodes the reproduction frame data by use of the parameter obtained as above. The described operation prevents expending the reproduction frame data with an incorrect parameter so as to normally fast-forward reproduce the compressed data. Furthermore, the present can select a frame used in the fast forward reproduction according to a feature index so that a section subjected to the fast-forward reproduction can be easily grasped by the user.

Abstract: A digital information reproducing apparatus in accordance with a prior art that uses a semiconductor memory to realize a memory means cannot reproduce digital data which has been encoded according to a compression coding form different from the one adopted by an incorporated decoding circuit. According to the present invention, a decoding program stored in a second semiconductor memory is selected according to a compression coding form adopted for digital data stored in a first semiconductor memory. The selected decoding program is used to decode the digital data by means of an arithmetic circuit. Thus, digital information can be reproduced irrespective of a compression coding form adopted for provided digital information.

Abstract: When evaluating defects, etc. of a sample by measuring thermal expansion displacement on the surface of the sample, which is produced by irradiating thereto an excitation beam of which intensity is cyclically modulated, a measuring beam having the displacement frequency F.sub.1 is irradiated to the vibrating surface of the sample, and the reflection beam is interfered with a reference beam having the frequency F.sub.2. The beat wave signal E.sub.1 (Beat frequency F.sub.b =F.sub.1 -F.sub.2) is converted to a binary signal E.sub.2. Then, the sample is evaluated by signals which are obtained by giving a suitable processing to the binary signals. In addition, the optic axes alignment is eliminated by utilizing the excitation beam itself concurrently as measuring beam.

Abstract: An apparatus for detecting position/variance of input light is disclosed which includes a photoelectric conversion device receiving input light constituted of a first resistive layer formed of a first photoelectric conversion material and a second resistive layer formed of a second photoelectric conversion material connected with the first resistive layer through a depletion layer or directly, wherein the first resistive layer is provided with uniform resistivity throughout its surface so that a linear output proportional to the average of the distances between one end of the photoelectric conversion device and positions of the input light is detected and the second resistive layer is provided with resistivity dependent upon the distance from its one end so that a quandratic ouput proportional to the average of the squares of the distances between one end of the photoelectric conversion device and positions of the input light is detected.

Abstract: A signal processing method in an electromagnetic induction test. A test object is subjected to an electromagnetic induction by use of N (N.gtoreq.1) kinds of test frequencies to obtain M (M.ltoreq.2N) kinds of phase detection outputs corresponding to respective states of the test object. The phase detection outputs are then sampled at a plurality of measuring points so that there exists n (n<M) kinds of disturbance factors of which a portion contribute to the electromagnetic induction test. The phase detection outputs have a variance greater than a variance of a target parameter of the test object and contribute to the electromagnetic induction test. A first coordinate axis Z, is determined in a direction in which a variance of a distribution of the group of the measuring points comes to be a maximum in an M-dimensional space formed with the coordinate axes associated with the M kinds of the phase detection outputs. The remaining coordinate axes are likewise determined.

Abstract: A surface inspection system detects imperfections on the surface of a hot radiant material, in which video signals for imperfections or defects are discriminated by comparison with normal level signals which are obtained through a variable area peak hold to preclude completely the influences of dark or bright defects which happen to be on the inspecting surface. The system includes apparatus for removing noises due to scales to produce outputs indicating true surface imperfections alone or indicating the degree of defectiveness of the detected defects. Also disclosed is a multi-camera surface inspection system capable of detecting defects on all sides of a hot radiant material which is transferred along a predetermined transfer line, with or without follow-up control of a camera or cameras scanning a given side of the material using edge signals detected from the normal level signal of another camera scanning a surface on the ensuing side of the material.