Abstract: An image sensing device comprises a stop to control the quantity of light coming from an object to be photographed; an image sensor; an automatic light quantity control system to control the stop according to a signal produced from the image sensor; a gain control circuit to control the gain of the signal produced from the image sensor; an operation member provided for manually operating the stop; and a memory to stabilize the gain of the gain control circuit in response to the operation member when the member is operated.

Abstract: A capacitor which is progressively chargeable in response to a switching on of the equipment, however brought about, is associated with an oscillating circuit with intervention threshold. As the load voltage of said capacitor increases the oscillating circuit shifts from a first to a second operating state, generating a switch-on current for the audio amplifier. The latter can be placed in stand-by condition by discharging to earth said capacitor by means of a suitable switch.

Abstract: For suppressing interference in an audio signal comprising a useful signal component and an interference signal component in the method according to the invention firstly the original audio signal is sampled and digitally recorded. At the same time the level of the interference signal component is separately detected and sampled, the sample values being stored as reference interference signal under the control of a computer retaining the phase relationship with respect to the original audio signal. The recorded digitized signal is then processed under the control of a computer at a predetermined speed and the interference signal component thereof is compensated in dependence upon the stored reference interference signal.

Abstract: There is provided in a car-mounted audio system an operator control section, a display section and a mechanical deck section in a central console or dashboard unit, wherein other units are located in hideaway positions, the system being characterized in that, a built-in microphone and a microphone amplifier are provided at the central control apparatus, buffers are provided at the hideaway units, and a microphone signal bus line is incorporated in the signal line connection between the central control and the hideaway units to couple a common microphone output signal therebetween.

Abstract: Some degree of cancellation of noise from an annular noise source can be achieved by using an annular noise generator surrounding the source and in antiphase therewith. However due to the dimensions of the annulus, constructive interference may occur at frequencies of interest. In the present invention an annular noise source is surrounded by inner and outer annular noise generators generating sounds which are in antiphase and in phase respectively with sounds from the noise source. Also sounds from the inner generator are of twice the amplitude of those from the source and the outer generator. In effect over a considerable frequency range, the noise source and the outer generator have a mean position which coincides with the inner generator and together they generate sounds which are of the same amplitude but opposite phase to sounds from the generator. Thus destructive interference occurs in the said frequency range.

Abstract: An audio crossover filter which automatically tunes the crossover frequency according to the content of the program audio which is being filtered.

Abstract: A semiconductor image sensor which has photocells arranged in a matrix form is miniaturized and integrated with high density, thereby to increase its light amplification factor and operating speed. To this end, each photocell is formed by a static induction transistor which has a pair of main electrodes, a channel region formed between the main electrodes and a capacitor connected between a control region serving as a photocell and one of the row lines.

Abstract: Method and apparatus for aiding hearing are disclosed comprising an automatic gain control unit which includes a first section for increasing the amplitude of input signal segments that are below a threshold level, and a second section for reducing the amplitude of input signal segments that are above said threshold level. Both sections have short attack and long release time constants. A long attack short release time constant noise suppressor unit responsive to the output from the second section and having a threshold level of operation below that of the threshold level of the automatic gain control units passes speech signals and squelches background noise signals between speech signal segments for improved understandability of speech signals.

Abstract: An automatic gain selector is disclosed for use with a noise suppression system which performs speech quality enhancement upon a noisy speech signal available at the input to generate a noise-suppressed speech signal at the output by spectral gain modification. The channel gain controller (240) of the present invention produces a modification signal (245), comprised of individual channel gain values, for application to a channel gain modifier (250). A particular gain table set is automatically selected from one of a plurality of gain tables (450) by a selector switch (470) and a noise level quantizer (440) in response to a multi-channel noise parameter, such as the overall average background noise level of the input signal. Then the individual channel gain values (455) are obtained from the particular gain table set in response to the individual channel signal-to-noise ratio estimate (235).

Abstract: An improved background noise estimator (320) is disclosed for use with a noise suppression system (300) for generating an estimate of the background noise power spectral density provided to noise suppressor (310), which performs speech quality enhancement upon the pre-processed speech-plus-noise signal available at the input to generate a clean post-processed speech signal at the output. Background noise estimator (320) utilizes an energy valley detector based upon post-processed speech to perform the speech/noise classification, and a noise spectral estimator based upon pre-processed speech to generate an estimate of the background noise power spectral density. As a result, the background noise estimate supplied to the noise suppressor is a more accurate measurement of the background noise energy, since it is performed during a more accurate determination of the occurrences of pauses in the speech.

Abstract: An electroacoustic motor for association with a horn comprising, in combination, a direct radiation speaker including a chassis, the speaker including a movable diaphragm, an acoustic wave transmitting means comprising an output orifice at the end thereof remote from said diaphragm, and passage means in the acoustic wave transmitting means communicating acoustic waves from the diaphragm to the output orifice. The acoustic wave transmitting means is a separate unit which is detachably secured to the speaker chassis by a fluid-tight connection. The acoustic wave transmitting means comprises a hollow truncated conical member of smaller diameter at the output orifice end thereof than at the end thereof contiguous the diaphragm. A phase adjustment element is positioned in the hollow interior of the truncated conical member, the phase adjustment element being in facing relation at one end thereof to the diaphragm and at the opposite end thereof to the output orifice of the truncated conical member.

Abstract: An improved noise suppression system (400) is disclosed which performs speech quality enhancement upon speech-plus-noise signal available at the input (205) to generate a clean speech signal at the output (265) by spectral gain modification. The noise suppression system of the present invention includes a background noise estimator (420) which generates and stores an estimate of the background noise power spectral density based upon pre-processed speech (215), as determined by the detected minima of the post-processed speech energy level. This post-processed speech (255) may be obtained directly from the output of the noise suppression system, or may be simulated by multiplying the pre-processed speech energy (225) by the channel gain values of the modification signal (245). This technique of implementing post-processed signal to generate the background noise estimate (325) provides a more accurate measurement of the background noise energy since it is based upon much cleaner speech signal.

Abstract: A miniature hearing aid (1) includes a microphone (12), a receiver (14) an amplifier (15), and a battery connectable via a contact (18), all of which are contained in a housing (2,3). The amplifier is constructed of a printed circuit board (20) and a plurality of components (21). In order to save space, the components (21) are countersunk in openings (24) in the circuit board (20) to reduce the vertical dimension of the amplifier. The openings (24) are used as temporary supports and for exact positioning for the components (21) by making them rectangular with cut off edges.

Abstract: A microphone picks up a signal in response to both the acoustic output of the speaker and the ambient noise at the loudspeaker location, for example, in an automobile. The microphone output signal and the signal which is to be provided to the loudspeaker with variable amplification are each subjected to envelope detection. The two envelope curve signals are compared to produce a signal representative of their similarity, the similarity being high when ambient noise is low or absent. The similarity signal is then processed with reference to a reference voltage which varies with the setting of the manual volume control of the amplifier interposed ahead of the loudspeaker. That amplifier has an automatic volume control input to which a control signal generated in response to the envelope similarity signal is applied to raise the amplification and the loudspeaker output level when ambient noise, detected by the similarity of the envelope signals, is present or increases.

Abstract: A camera apparatus comprising focusing means for optically focusing a beam of light from an object, an imaging element for converting an optical image produced by the focusing means into electrical or physicochemical information and issuing or recording the information as an image, detectors for detecting fluctuations of the apparatus to issue a fluctuation detecting signal, controllers responsive to the fluctuation detecting signal for issuing an image fluctuation control signal, and suppressors responsive to the image fluctuation control signal for suppressingfluctuations of the image due to the fluctuations of the apparatus.

Abstract: A mobile sound field correcting system for correcting an acoustic characteristic in a vehicle sound field formed by direct waves radiated from loudspeakers and reflected waves thereof providing satisfactory acoustic characteristics for different vehicles and different listening points within a vehicle. A first correcting means corrects a power spectrum of each loudspeaker in a frequency range above a frequency at which a decrease of starts of the power spectrum in a high-frequency range of each loudspeaker. Second correcting means corrects for irregularities in the frequency characteristic of each loudspeaker caused by interference of the direct waves with the reflected waves in a frequency lower than the drop-off frequency of this power spectrum.

Abstract: An automatic focusing device for a video camera includes a projector for projecting an infrared ray used for measuring distances and a converging lens for focusing reflected infrared ray light from an object whose distance is to be measured. A light spot detector and a computer are provided for determining whether the video camera is in focus. A lens encoder is utilized to determine the position of a focusing lens and a lens driving unit moves the position of a photographic lens used for photographing the object forwardly or backwardly in dependence upon outputs from the lens encoder and computer so as to automatically focus the video camera in response to the infrared rays reflected from the object to be photographed.

Abstract: A method of and apparatus for scanning annularly arranged images on a disc film arranged for rotation about its axis so as to present sequentially the images at a scanning station, is provided.To correct for keystone distortion of a scanned image, a dove prism or equivalent mirror box is located on the optical axis and is rotated about such axis at half the speed of rotation of the disc.

Abstract: An electronic stethoscope is disclosed having a palm sized electronic component case with operating switches provided on opposite sides of the case for ease of operation. The stethoscope includes a pickup head coupled to an electronic microphone by means of a flexible tubular acoustic member. A battery powered amplifier and filter circuit is provided within the component case and the amplified and filtered output of the microphone is coupled to a miniature speaker sealed within an airtight container within the case. A rotatable tubular member having radial apertures therein is coupled through the sealed container and out each side of the component case. A binaural headpiece is acoustically coupled to each end of the rotatable member and is thus free to rotate with respect to the case, allowing the stethoscope to fold for storage.

Abstract: The invention relates to acoustically radiating randomly large rooms and surfaces according to propagation time principles, whereby action or representation and reception or listening areas border directly on one another or are identical. Its object is to avoid error locations and skipping effects caused by movements, which are especially interfering for important solo sound sources. The resulting object of realizing a propagation time staggering without limiting source areas, and responding to the acoustic capacity of the sources, is solved by means of a control device connected to the delay or amplification devices, and which differentiatedly controls them analogous to the sound paths between the source and the acoustic radiator locations.