Abstract: An antenna device capable of not only achieving multiple resonances and wideband characteristics but also achieving improvement of antenna efficiency and accurate matching at all resonant frequencies, and a wireless communication apparatus. In one example, an antenna device 1 includes a radiation electrode 2 to which power is capacitively fed through a capacitor portion C1, and additional radiation electrodes 3-1 to 3-3 branched from the radiation electrode 2. A distal end portion 2a of the radiation electrode 2 is grounded to a ground region 402, and is a portion at which a minimum voltage is obtained when power is fed. A capacitor portion C2 that is a portion at which a maximum voltage is obtained when power is fed is disposed in a proximal end portion 2b of the radiation electrode 2, and a variable capacitance element 4 which is grounded is connected in series with the capacitor portion C2.

Abstract: An antenna device and a wireless communication apparatus that are capable of obtaining a plurality of resonant frequencies and varying the plurality of resonant frequencies over a wide range are provided. A first antenna unit of an antenna device includes a feed electrode, a first radiation electrode, and a first frequency-variable circuit. The first frequency-variable circuit includes first and second reactance circuits each including a variable-capacitance diode. A control voltage is applied to the first frequency-variable circuit, and the resonant frequency of the first antenna unit can thus be varied. A second antenna unit includes the feed electrode, a second radiation electrode, and a second frequency-variable circuit. The second frequency-variable circuit includes first and third reactance circuits each including a variable-capacitance diode. A control voltage is applied to the second frequency-variable circuit, and the resonant frequency of the second antenna unit can thus be varied.

Abstract: A radiation electrode is formed on a substrate of a surface mount antenna. One end of the radiation electrode forms a ground connection portion connected to ground, and the other end of the radiation electrode forms an open end. A ground connection electrode for connecting the open end of the radiation electrode to ground via a capacitance is provided on the substrate. No feeding electrode for feeding power to the radiation electrode is provided on the substrate. This surface mount antenna is mounted on a non-ground region (a region on which a ground electrode is not formed) of a board so as to constitute an antenna structure. On the board of the antenna structure, a feeding electrode for capacitively feeding power to the radiation electrode is provided at a position between the ground connection portion and the open end.

Abstract: A compact and thin antenna device can be mounted in a small area of a substrate and has a multiband capability adaptable to various applications. The antenna device includes a chip antenna, an antenna element, and a chip antenna. The chip antenna is produced by forming a radiation electrode on the surface of a dielectric base, and mounting a frequency variable circuit on the radiation electrode. Thus, it becomes possible to obtain a resonant frequency f1 of the chip antenna and further to vary the resonant frequency f1. The antenna element is produced by adding an auxiliary element to an additional radiation electrode for the chip antenna. The chip antenna includes a radiation electrode on a dielectric base and a conductive pattern. Thus, a resonant frequency f2 and a resonant frequency f3 of the antenna element and the chip antenna, respectively, can be obtained.

Abstract: An antenna and a wireless communication device are adapted to have a plurality of resonant frequencies changed simultaneously by a desired range at a low voltage. The antenna includes a first antenna section and a second antenna section. The first antenna section includes a feeding electrode, a frequency-changing circuit, and a radiating electrode, and the second antenna section includes the feeding electrode, a first reactance circuit, and an additional radiating electrode. The frequency-changing circuit has a circuit configuration in which the first reactance circuit and the second reactance circuit are connected. When a control voltage Vc is applied to a node P, the reactances of the first and second reactance circuits change in accordance with the magnitude of the control voltage Vc, so that a resonant frequency f1 of the first antenna section and a resonant frequency f2 of the second antenna section change simultaneously.

Abstract: A compact and thin antenna device can be mounted in a small area of a substrate and has a multiband capability adaptable to various applications. The antenna device includes a chip antenna, an antenna element, and a chip antenna. The chip antenna is produced by forming a radiation electrode on the surface of a dielectric base, and mounting a frequency variable circuit on the radiation electrode. Thus, it becomes possible to obtain a resonant frequency f1 of the chip antenna and further to vary the resonant frequency f1. The antenna element is produced by adding an auxiliary element to an additional radiation electrode for the chip antenna. The chip antenna includes a radiation electrode on a dielectric base and a conductive pattern. Thus, a resonant frequency f2 and a resonant frequency f3 of the antenna element and the chip antenna, respectively, can be obtained.

Abstract: An antenna and a wireless communication device are adapted to have a plurality of resonant frequencies changed simultaneously by a desired range at a low voltage. The antenna includes a first antenna section and a second antenna section. The first antenna section includes a feeding electrode, a frequency-changing circuit, and a radiating electrode, and the second antenna section includes the feeding electrode, a first reactance circuit, and an additional radiating electrode. The frequency-changing circuit has a circuit configuration in which the first reactance circuit and the second reactance circuit are connected. When a control voltage Vc is applied to a node P, the reactances of the first and second reactance circuits change in accordance with the magnitude of the control voltage Vc, so that a resonant frequency f1 of the first antenna section and a resonant frequency f2 of the second antenna section change simultaneously.

Abstract: An optical disc apparatus capable of performing a still operation includes a circulation-number counter (4) counting a circulation number of the optical disc (1) and a control unit (6) obtaining the accumulated circulation number (4) of the optical disc (1) after start of the still operation from the circulation-number counter (4) and, when the accumulated circulation number attains a predetermined circulation number n (n>1) as said predetermined value, controlling the pickup (3) so as to perform a track-jump for being placed back by n tracks toward the start position of reading the optical disc (1).

Abstract: An optical disk drive restricts its rotation speed based on information obtained from a disk. The optical disk drive includes a checking unit that checks whether disk information stored on an optical disk is registered in a database, and a restriction unit that restricts, if the disk information is not in the database, a maximum rotation speed of the optical disk drive.

Abstract: An optical disk, a method for manufacturing an optical disk, an optical disk device and a method for writing/reading an optical disk, wherein the optical disk is of a write/read type having two layers of write films, enabling the state of the write/read beam to be kept constant when writing onto or reading out of a second write film without being affected by variations in the write state of a first write film, is to be provided. In an optical disk configured by stacking, enumerated in the direction of incidence of a write/read beam, a disk substrate, a first write film, an adhesive layer, a second write film, another disk substrate and an aluminum reflective layer, when performing read/write onto or out of a write film which is the second write film, the write/read beam is focused on the second write film after being transmitted by the disk substrate, the first write film, the adhesive layer, the second write film and the other disk substrate and reflected by the aluminum reflective layer.

Abstract: A switch knob 1 having an operation portion 2, a cam system 3, a driving system 4, a steel ball 5, and a spring 6. The cam system 3, which is made of a molded, light transmissive material, is insertion molded into the operation portion 2, which is made of an opaque material. The cam system 3 includes an integral indicator 31 having a projected portion 32. A designated symbol is formed by the projected portion 32, which is exposed through the operation portion 2. Since the cam system 3 attached on the back side of the operation portion is light transmissive, the cam system 3 does not cause any inconsistency in the light at the indication portion. In addition, the number of parts comprising the switch knob 1 are minimized, and it is possible to maintain the quality of the symbols for extended periods.

Abstract: A switch assembly with internal electronic components that enables easy assembly and is dustproof, and that can be oriented relative to the main board of a power window control switch or other devices with a lesser degree of limitation and has a wide variety of applications. A plurality of electronic components are mounted to one side of a plate 1. A plurality of switch electrodes 3 are formed in the other side of the plate 1. A switch case 6 is resiliently fit over the base plate 1. The switch case 6 includes an elongated aperture 61 within which a lever 41 of a switch operating mechanism 4 is loosely fit, pawls 62 adapted for resilient engagement with the base plate 1, projections 63 and a base 64. The switch operating mechanism 4 holds a movable contact 5. The switch case 6 defines a space 65 adjacent to the switch operating mechanism 4 and the movable contact 5. The switch electrodes 3 are sealably contained within the space 65 when the switch case 6 is resiliently fit over the base plate 1.