U.S. Philips Corporation

Johannes P Damen

Gijsbertus De With

Cornelis H Witmer

Klaas Prijs

Eelco G Visser

Piet F Bongers

Doeko Stoppels

Johannes A Pistorius

Roelof A Venema

Robert De Vries

Theodorus J Berben

A hearing aid, in particular a behind-the-ear hearing aid, comprising a first unit (1) that includes an amplifier (4), a hook (3) formed with a duct (16) and a space (8). A second unit (2) includes an electro-acoustic transducer (12). The second unit is intended to be worn in the ear. A tubular element (15) for the mechanical connection of the two units accommodates connecting means (14) for electrically coupling the transducer (12) to the amplifier (4). The element (15) is axially slidable inside the duct. This enables the hearing aid to be adapted to the size of the ear of the person wearing the hearing aid. The connecting means (14) is long enough so that even for a big ear, the electrical connection is still intact or can be made. When the hearing aid is adapted to a smaller ear, the connecting means (14) is then too long but the space (8) takes up the excess length of the connecting means.

Hearing aid with adjustable flexible connection member

A magnetic head (32) having a magnet core (30) of ferrite and a layer of a bonding material (28) consisting of glass in the gap-forming area of the magnet core (38). In order to ensure that on the one hand the ferrite be not attacked by the glass during the bonding process and that on the other hand the temperature adjustment during the bonding process is not too critical, double layer diffusion barriers are provided between the layer of bonding material (28) and the core parts (10) and (10'), respectively, which barriers are formed by a layer of silicon nitride (26) on the side of the bonding layer (28) and a layer of silicon oxide (24) on the side of the core parts (10) and (10'), respectively.

Method of manufacturing a glass-bonded magnetic head having diffusion

A magnetic head (32) includes a magnet core (30) of ferrite and a layer of a bonding material (28) consisting of glass in the gap-forming area of the magnet core (38). In order to ensure that the ferrite is not attacked by the glass during the bonding process and that the temperature adjustment during the bonding process is not too critical, double layer diffusion barriers are provided between the layer of bonding material (28) and the core parts (10), (10'), respectively. Each barrier is formed by a layer of silicon nitride (26) on the side of the bonding layer (28) and a layer of silicon oxide (24) on the side of the core.

Glass-bonded magnetic head having diffusion barriers

Magnetic head for a magnetic recording and playback apparatus includes a core of a Mn--Zn-ferrous ferrite having a very high saturation magnetization. The Mn--Zn-ferrous ferrite has a composition (not counting optional substitutions) according to the formula

Magnetic head

A method of manufacturing a single crystal of a composite oxide by gradual solidification of a melt with solidification starting from a seed crystal which initially is in contact with the melt, is provided wherein to obtain a single crystal having a composition which is as homogeneous as possible (homogeneous within 1 mol. %) the following measures are taken: first, initially the melt consists of no more than 25% by weight of the single crystal to be grown; and second, during the solidification process molten material is added to the melt at the same rate and having the same composition as material solidifies out from the melt.

Method of manufacturing single crystals

A novel non-magnetic monocrystalline garnet substrate material in the form of calcium--gallium-germanium garnet. Single crystals of calcium-gallium-germanium garnet can be grown at mush lower temperatures by means of the Czocharalski method than single crystals of the conventional rare earth-gallium garnets. These single crystals are very suitable to epitaxially grow bubble domain films thereon, in particular films on the basis of Lu.sub.3 Fe.sub.5 O.sub.12.

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Eindhoven, Netherlands

Johannes P Damen