Illuminated rotatable knob

• US 6,224,221 B1
• Filed: 06/30/1999
• Issued: 05/01/2001
• Est. Priority Date: 07/30/1998
• Status: Expired due to Fees

• Current Assignee: Preh-Werke GmbH & Company KG
• Original Assignee: Preh-Werke GmbH & Company KG
• Inventors: Glienicke, Haiko
• Primary Examiner(s): Husar, Stephen
• Assistant Examiner(s): Ward, John Anthony
• Application Number:
  US09/343,727
• Time in Patent Office: 671 Days
• Field of Search: 362/5, 362/28, 362/29, 362/30, 116/286, 116/287, 116/288, 116/DIG. 36, 116/DIG. 5
• US Class Current: 362/23
• CPC Class Codes: G02B 6/0033 Means for improving the coupling-out of light from the light guide
• CPC Class Codes: G05G 1/105 comprising arrangements for illumination
• CPC Class Codes: H01H 19/025 Light-emitting indicators
• CPC Class Codes: H01H 2219/06 Reflector
• CPC Class Codes: H01H 2219/062 Light conductor
• CPC Class Codes: H01H 2219/0622 only an illuminated ring around keys
• CPC Class Codes: H01H 9/182 Illumination of the symbols or distinguishing marks H01H9/181 takes precedence
• CPC Class Codes: Y10S 116/36 Illuminated dial and pointer

Abstract

A rotatable knob for a control apparatus which is less complex than similar devices and which provides greater self-illumination than do similar devices. In the case of the present rotatable knob, a total reflection surface (13) is established wherein the obverse side (14) of the total reflection surface (13) forms a mantle of a conical or cup-shaped frustum upon which segment-like 90° prisms (16) are radially arranged. Accordingly, the present rotatable knob may be used in operational components for radios, air conditioning units, and the like in motor vehicles.

Claims

1. A rotatable knob of a control apparatus with electric components and an illuminating arrangement,

comprising a light source which is positioned before a first light-transmitting body, said first light-transmitting body being situated within the rotatable knob, possessing a light entry surface arranged at a rotational center of said rotatable knob and having a peripheral light-output portion which terminates within a transparent housing part, said transparent housing part comprising an externally visible scale,

wherein said transparent housing part further contains a second light-transmitting body fixed in the transparent housing, which second light-transmitting body is disposed between the scale and the peripheral light output portion of the first light-transmitting body, and

wherein said second light-transmitting body comprises a total refection surface in a light path of light traveling from said light output part to said scale, which total reflection surface comprises an outer face forming an envelope of a cup-shaped frustum on which segment-shaped 90°

are arranged.

2. The rotatable knob of claim 1, wherein the cup-shaped frustum lies within an angle determined to provide a given light output beam from the second light-transmitting body.

3. The rotatable knob of claim 1, wherein the first light-transmitting body comprises a further light output area which effects a light output beam in a direction of a translucent zone with a pointer mark in the rotatable knob.

4. The rotatable knob of claim 1, wherein the first light-transmitting body and the second light-transmitting body contain light-diffusing particles.

5. The rotatable knob of claim 1 wherein the cup-shaped frustum has a conical shape.