1. A rotor shaft for a magnetic bearing device, said rotor shaft comprising a inner shaft portion and at least one substantially annular target for an electromagnet, said target being disposed on a periphery of said inner shaft portion said target is being held between two collars exerting an axial pressing force on said tar-get in a manner such that said axial pressing force is strongest near an outer periphery of said rotor shaft.
2. The rotor shaft according to claim 1, wherein said axial pressing force is stronger than any radial force between said target and said inner shaft portion when the rotor shaft is at standstill.
3. The rotor shaft according to claim 1, wherein said target comprises a plurality of stacked annular sheets extending essentially in a radial direction.
4. The rotor shaft according to claim 1, wherein a gap is present between said target and said inner shaft portion, and wherein a gap filling material is disposed in the gap.
5. The rotor shaft according to claim 1, wherein at least one of said collars is formed by an annular protrusion disposed near said outer periphery of said rotor shaft and protruding axially towards said target
6. The rotor shaft according to claim 1, wherein said rotor shaft comprises a spacer separating said target from a further target, and wherein one of said collars is formed by said spacer.
7. The rotor shaft according to claim 1, wherein said inner shaft portion has a substantially cylindrical portion surrounded by said target, a shoulder substantially extending from said cylindrical portion in a radial direction, and an annular protrusion disposed on said shoulder and protruding in the axial direction, and wherein one of said collars is formed by said annular protrusion.
8. The rotor shaft according to claim 1, wherein said inner shaft portion has a male thread, and wherein a nut having a female thread interacting with said male thread is mounted on said inner shaft portion (210) to exert said pressing force.
9. The rotor shaft according to claim 1 wherein at least one of said target and said collars comprises at least one of a depression and a protrusion for centering said target in a radial direction.
10. The rotor shaft according to claim 1, said rotor shaft comprising a thrust disk having an outer periphery and, a thickness which radially decreases towards the periphery in a substantially continuous manner.
11. The rotor shaft according to claim 10, wherein said thrust disk has a first region with a first substantially uniform thickness, said first region being disposed near said inner shaft portion, and a second region with a second substantially uniform thickness smaller than said first uniform thickness, said second region being disposed near the periphery of the thrust disk, and a tapered region between said first and said second region in which the thickness decreases towards the periphery from said first uniform thickness to said second uniform thickness in a substantially continuous manner.
12. A magnetic bearing device comprising a rotor shaft according to claim 1 and comprising at least one active magnetic bearing unit.
13. A method for manufacturing a rotor shaft comprising the steps of
providing an inner shaft portion having a substantially cylindrical portion, a collar disposed on one axial side of said cylindrical portion and a male thread disposed on another axial side of said cylindrical portion;
providing a plurality of stacked annular sheets for forming a target;
providing a nut having a female thread;
sliding said plurality of stacked annular sheets onto said substantially cylindrical portion of said inner shaft portion to form said target; and
fastening said nut with said female thread onto said male thread for exerting an axial pressing force onto said target in a manner that said axial pressing force is largest near an outer periphery of said rotor shaft.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A display apparatus comprising:
a chassis base;
a display panel adjacent to a first side of the chassis base;
a driving circuit board attached to a second side of the chassis base, the second side being opposite the first side;
a driver integrated circuit electrically connected to electrodes of the display panel and to the driving circuit board at a position between the electrodes and the driving circuit board, the driver integrated circuit selectively providing a voltage to the electrodes of the plasma display panel in accordance with signals controlled by the driving circuit board; and
a heat dissipation unit positioned adjacent an edge of the display panel, wherein the heat dissipation unit dissipates heat from the driver integrated circuit, the heat dissipating unit including a thermally conductive metallic pattern and at least one heat sink located adjacent to at least one lengthwise end portion of the thermally conductive metallic pattern.
2. The display apparatus of claim 1,
wherein the driver integrated circuit is a chip on glass type;
wherein the driver integrated circuit is bonded on the edge of the display panel; and
wherein the driver integrated circuit is electrically connected to electrode terminals of the display panel via a flexible printed circuit.
3. The display apparatus of claim 1, wherein the thermally conductive metallic pattern is made of silver.
4. The display apparatus of claim 1, wherein the thermally conductive metallic pattern is made of one of the group consisting of copper and chromium.
5. The display apparatus of claim 1, wherein the heat dissipation unit further comprises a heat sink in contact with each of lengthwise end portions of the thermally conductive metallic pattern.
6. The display apparatus of claim 2, wherein an electrical insulation layer is formed on both the electrode terminals of the display panel connected to the driver integrated circuit and on the connecting terminals of the flexible printed circuit connected to the driver integrated circuit.
7. The display apparatus of claim 6, wherein the electrical insulation layer is made of one of the group consisting of a silicone resin and an epoxy resin.
8. The display apparatus of claim 1, wherein an electrical insulation layer is formed on the driver integrated circuit as well as on both electrode terminals of the display panel connected to the driver integrated circuit and the connecting terminals of a flexible printed circuit connected to the driver integrated circuit.
9. The display apparatus of claim 8, wherein the electrical insulation layer is made of one of the group consisting of a silicone resin and an epoxy resin.
10. The display apparatus of claim 1, wherein the electrodes of the display panel are address electrodes.
11. The display apparatus of claim 1, wherein the display panel is a plasma display panel.
12. A heat dissipation unit for a chip on glass driver integrated circuit mounted on a substrate comprising:
a thermally conductive metal pattern formed along an edge of the substrate, the thermally conductive metal pattern contacting the chip on glass driver integrated circuit and being electrically isolated from any electrode terminals; and
at least one heat sink located adjacent to at least one end portion of the thermally conductive metal pattern.
13. The heat dissipation unit of claim 12, wherein the thermally conductive metal pattern is formed in a line shape.
14. The heat dissipation unit of claim 12, further comprising two heat sinks, each heat sink located adjacent to one end portion of the thermally conductive metal pattern.
15. The heat dissipation unit of claim 12, wherein the thermally conductive metal pattern is made of a material with high thermal conductivity.
16. The heat dissipation unit of claim 15, wherein the material is selected from one of the group consisting of silver, copper and chromium.