摘要:
A speaker system has an acoustic diaphragm and an image projection screen provided on a surface of the diaphragm integrally therewith so as to enable the user to enjoy both realistic image on the screen and powerful sound reproduced through the diaphragm. The rear surface of the diaphragm is closed at a peripheral portion thereof while the central portion of the rear surface of the diaphragm is opened to the exterior, so that the speaker system can provide a high level of reproduced sound pressure in low-pitched region, while the thickness of the speaker is reduced remarkably. The diaphgram can be driven by a plurality of driving units so that the speaker system can operate only with an ordinary stereophonic amplifier. The diaphragm can be composed of a pair of diaphragm elements capable of vibrating independently of each other and the screen may be integrally and commonly attached to the surfaces of these diaphragm elements in such a manner as to allow the diaphragm elements to vibrate independently of each other, whereby the speaker system can operate in stereophonic mode. Any variation in the acoustic characteristic attributable to variation in the condition of installation is compensated for by a change in the ratio of the opened area of the rear surface of the diaphragm to the whole effective vibration area or by a selective provision of a sound absorbing member on the rear side of the cabinet.
摘要:
A speaker which is thin but which is capable of providing high-fidelity reproduction and ensuring a suitable level of sound pressure even when it is brought close to a wall. A closed chamber is formed behind one part of a disphragm mounted in an enclosure, and an open chamber is formed behind another part of the diaphragm. At least one voice coil driver unit is connected to the diaphragm. The phase difference between sounds radiated from the front and rear surfaces of the diaphragm is increased as large as possible by using an acoustic duct for the sound radiated through the open chamber, thereby minimizing cancellation of sounds and improving the sound pressure level.
摘要:
A speaker includes a diaphragm, a frame accommodating the diaphragm and an edge attached to an outer periphery of the diaphragm as well as to an inner periphery of the frame so as to retain the diaphragm within an interior of the frame. The edge has a thickness which is smallest at substantially a central portion between the diaphragm and the frame and the vicinity thereof, and increases toward the diaphragm and the frame.
摘要:
An electrodynamic loudspeaker which comprises a generally rectangular flat vibrating plate, and first and second magnetic drives for driving the vibrating plate to produce vibrations. The first magnetic drive is so positioned as to drive the vibrating plate at a first location corresponding to one of two line nodes m.sub.1 and m.sub.2 of vibration of a first predetermined frequency f.sub.1 which would be produced when the vibrating plate is driven at the center thereof, whereas the second magnetic drive is so positioned as to drive the vibrating plate at a second location corresponding to one of four line nodes n.sub.1, n.sub.2, n.sub.3 and n.sub.4 of vibration of a second predetermined frequency f.sub.3 which would be produced when the vibrating plate is driven at the center thereof. Each of all of the line nodes extends in parallel to the shorter sides of the rectangular shape of the vibrating plate.
摘要:
A speaker system which has a speaker unit with a diaphragm and an acoustic path provided on the front side of the diaphragm so as to guide sound waves emitted from the diaphragm. The acoustic path is defined by a sound absorbing member. The space in the acoustic path and the sound absorbing member is separated by a partition member which is disposed in such a manner that at least a portion of the sound absorbing member is exposed to the space in the acoustic path, except that the portion of the sound absorbing member just adjacent the diaphragm is not exposed to the acoustic path. This arrangement eliminates peaks and troughs of resonance determined by the length of the acoustic path, so that flat sound pressure frequency characteristics can be obtained over a wide range up to high-pitch tone region.
摘要:
A headphone is designed to have two resonant peaks for simulating loudspeaker reproduction. The headphone comprises a housing in which an electroacoustic transducer with a diaphragm is positioned, wherein the housing is formed with a rearward cavity positioned adjacent to the diaphragm remote from the listener's ear to provide an acoustic compliance to the generated acoustic energy. In order to generate the two resonant peaks to simulate a sensation of realism as if the listener is hearing sound from a loudspeaker, the rearward cavity is communicated with the atmosphere through apertures. The acoustic compliance of the rearward cavity coacts with the apertures to produce two resonant peaks at frequencies corresponding to the frequencies of the peaks which occur in a signal from the loudspeaker.
摘要:
A loudspeaker system which comprises a loudspeaker unit for radiating a first sound, a horn unit having a throat coupled to the back of the loudspeaker for radiating a second sound, and an acoustic filter provided in the horn for causing an acoustic impedance of the horn unit to be discontinuous. When the minimum frequency of cyclic dales of the sound pressure observed in the characteristic curves of a sound pressure of a composite of the first and second sounds as a result of a phase delay brought about by the length of the horn unit is expressed by fd, a primary harmonic resonance can be produced between the loudspeaker unit and the acoustic filter which is similar to that produced by a straight acoustic tube having its opposite ends closed, thereby to render the frequency of the primary resonance to be generally equal to the frequency fd.
摘要:
A recording device includes a recording medium operable to store a plurality of program streams and information about recording of each program stream, and a controller operable to control display of the program stream recorded on the recording medium on a display device. When receiving an instruction for selecting a predetermined item from among the plurality of selection items, the controller causes the menu image to be displayed, making the menu image include information representing programs corresponding to at least a part of the plurality of the program streams recorded on the recording medium, in addition to the plurality of selection items.
摘要:
Disclosed is a female physical condition managing apparatus comprising: a bioelectrical impedance-meter; a memory for storing the so determined values of bioelectrical impedance; a decision-making unit for making a decision about the physical or mental condition of a woman on the basis of the time series analysis, which is made on the variation of the determined values of bioelectrical impedance; and a display showing the physical or mental condition of the woman in the form of graphs. This permits women to realize quickly what physical or mental condition they are put in. The female physical condition includes the premenstrual syndrome.
摘要:
A recording device includes a recording medium operable to store a plurality of program streams and information about recording of each program stream, and a controller operable to control display of the program stream recorded on the recording medium on a display device. When receiving an instruction for selecting a predetermined item from among the plurality of selection items, the controller causes the menu image to be displayed, making the menu image include information representing programs corresponding to at least a part of the plurality of the program streams recorded on the recording medium, in addition to the plurality of selection items.