LIGHT PIPE APPARATUS

Abstract: A light pipe apparatus is configured to mount on a printed circuit board and includes a base including an indicator surface and a printed circuit board mating surface. The light pipe apparatus further includes a plurality of light pipes configures to be mounted to the base.

Description: LIGHT PIPE APPARATUS BACKGROUND OF THE INVENTION This invention relates generally to indicators for determining the operational status of electronic equipment and more specifically to the transmission of light as an indicator of operational status. Indicators such as light emitting diodes (LEDs) are typically used to indicate status, power, and required actions in many different types of equipment. When LEDs are mounted on a printed circuit board, it sometimes is difficult to position the LEDs so that an operator can easily view an LED to determine whether the LED is energized. For example, the printed circuit board typically may be positioned within a housing and on a plane substantially perpendicular to a plane on which a housing display surface is located. In an attempt to overcome the problem set forth above, the LEDs sometimes are mounted on a separate, smaller circuit board and a wiring bundle electrically connects the LEDs to components on the main circuit board. The smaller LED circuit board can then be located adjacent the housing display surface and in a selected orientation so that an optical signal emitted from the LEDs can be more easily viewed. Of course, adding a separate LED circuit board and a wiring bundle leads to additional costs and complexity. Rather than a separate LED circuit board and wiring bundle, a light pipe can be used to transmit an optical signal from an LED mounted on the main circuit board. One know light pipe includes multiple light passageways so that if multiple LEDs are required, optical signals from each LED can be transmitted through a respective passageway of the light pipe. In order to avoid optical crosstalk, such light pipe includes reflecting surfaces for re-directing light into the appropriate passageway. Requiring such reflecting surfaces increases the complexity of the shape of the light pipe. BRIEF SUMMARY OF THE INVENTION In one aspect, the present invention is directed to a light pipe apparatus that includes, in an exemplary embodiment, a base having a circuit board mounting portion configured to be mounted on a printed circuit board and a support. The support includes an indicator surface. In the exemplary embodiment, a plurality of light pipes extend from the circuit board mounting portion to the support. More specifically, each light pipe has one end located within an opening in the circuit board mounting portion and aligned with a respective LED, and one end located within an opening in the support and associated with a respective indicator, or legend, on the indicator surface. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a light pipe apparatus; Figure 2 is a cross-section view through the circuit board mounting portion of the base; Figure 3 is illustrates an exemplary legend; Figure 4 is a side view of one set of light pipes; Figure 5 is a bottom view of the light pipe shown in Figure 1; and Figure 6 is a side view of a light pipe. DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows a perspective view of an exemplary embodiment of a light pipe apparatus 10 including a base 12 and a plurality of light pipes 14. In the exemplary embodiment, light pipes 14 are formed in a molded set. Each light pipe 14 includes one or more stops 16 which serve to stop a first end of each light pipe 14 at a proper mechanical position relative to base 12. Base 12 is, in one embodiment, molded as one piece and includes a support 18. Support 18 includes an indicator surface 20 and clips 22 for detaining an legend (described below). Support 18 also includes light pipe openings 24 into which a second end of light pipes 14 are inserted when mounted in base 12. A single pipe opening 25, described below in further detail is also included in support 18. Base 12 further includes, in the embodiment shown in Figure 1, a printed circuit board mating, or mounting, portion 26, an end 28 and a plurality of openings (not shown) passing through portion 26 from a top surface 30 to a bottom surface 32. The first ends of light pipes 14 are inserted into top surface 30 when mounted onto base 12. Bottom 32 of printed circuit board mating portion 26 further includes a plurality of mounting guides 34 used when mounting apparatus 10 onto a circuit board (not shown). Figure 2 is a cross-sectional view of circuit board mounting portion 26 of base 12 (shown in Figure 1), and shows openings 40 including upper portions 42 and lower portions 44. Upper portion 42 of openings 40 are configured to slidably engage the first ends of light pipes 14 (shown in Figure 1). Bottom portions 44 of openings 40 are configured to allow circuit board mounting portion 26 to fit over, or be positioned adjacent to, surface mounted LEDs (not shown) on a printed circuit board (not shown). Mounting guides 34 extend from bottom surface 32. Figure 3 is one embodiment of an legend 50. Legend 50 includes a plurality of slots 52 through which clips 22 (shown in Figure 1) extend to maintain legend 50 adjacent to indicator surface 20 (shown in Figure 1). In one embodiment, legend 50 is fabricated from a material having a black matte finish except for letters and numbers which are clear. Light transmitted through one of respective light pipes 14 and to the second end of that light pipe 14 illuminates the corresponding alphanumeric character on legend 50. Figure 4 is a side view of light pipes 14 which, in the exemplary embodiment, are connected by a plurality of molded links 60. Molded links 60 maintain light pipes 14 in fixed relation to each other so that light pipes 14 can be inserted as one single unit into base 12. In one embodiment, light pipes 14 together with molded links 60 are molded from a clear plastic material, for example, Lexan® plastic. The mark Lexan is a registered trademark of General Electric Company. Figure 5 is a bottom isometric view of light pipe apparatus 10 including base 12 and light pipes 14. Base 12 is configured for two sets of multiple light pipes 14. Base 12 can be configured for any number of light pipes and light pipe sets. Apparatus 10 also includes a light pipe 70 which functions similar to light pipes 14, but is a single standalone light pipe, and not connected to other light pipes with molded links (described above). Pipe 70 is adjacent to an opening 72 similar to openings 40 described above, but light enters single pipe 70 from a side 74 of opening 72. Figure 6 is a side view of pipe 70 which includes a first end 82 which accepts light from, for example, an LED inside of opening 72 (shown in Figure 5). Single pipe 70 also includes a second end 84 which transmits light through a single pipe opening 25 in base 12 (both shown in Figure 1). A retention tab 86 is molded onto single pipe 70 and is configured to engage a similarly shaped opening in base 12 to retain single pipe 70 position. While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.

Claims: WHAT IS CLAIMED IS: 1. A light pipe apparatus configured to be mounted on a printed circuit board, said apparatus comprising: a base comprising a printed circuit board mating portion configured to mount on a printed circuit board and a support comprising an indicator surface; and a plurality of light pipes configured to be mounted to said base. 2. An apparatus according to Claim 1 further comprising a legend configured to be mounted to said base and to filter light from said light pipes. 3. An apparatus according to Claim 2 wherein said legend includes at least one alphanumeric character for filtering light from said light pipes. 4. An apparatus according to Claim 1 wherein said base includes a plurality of openings in a bottom of said printed circuit board mating portion, each said opening configured to be positioned adjacent a light source mounted on a printed circuit board. 5. An apparatus according to Claim 4 wherein said openings extend through a top surface of said printed circuit board mating portion thereby allowing said light pipes to be optically interfaced to the light emitted by the light source. 6. An apparatus according to Claim 1 wherein at least two of said light pipes are molded together as a single unit and are configured to be mounted in said base as a single unit. 7. An apparatus according to Claim 6 wherein said apparatus comprises at least two single units of said light pipes. 8. An apparatus according to Claim 1 wherein said light pipes are molded from a clear plastic material. 9. An optical indicator system for mounting on a printed circuit board, said optical indicator system comprising: a plurality of light emitting diodes (LEDs) configured to be mounted on the printed circuit board; and a light pipe apparatus configured to be mounted on the printed circuit board said light pipe apparatus comprising: a base comprising a printed circuit board mating portion configured to mount on the printed circuit board and a support comprising an indicator surface; and a plurality of light pipes mounted to said base, said light pipes configured to transmit light from said LEDs to said indicator surface. 10. An optical indicator system according to Claim 9 further comprising a legend mounted to said indicator surface of said support and configured to filter light from said light pipes. 11. An optical indicator system according to Claim 10 wherein said legend includes at least one alphanumeric character for filtering light from said light pipes. 12. An optical indicator system according to Claim 9 wherein said base comprises a plurality of openings in a bottom of said printed circuit board mating portion, each said opening configured to be positioned adjacent one of said light emitting diodes (LEDs) mounted on the printed circuit board. 13. An optical indicator system according to Claim 12 wherein said openings extend through a top surface of said printed circuit board mating portion thereby allowing said light pipes to be optically interfaced to light emitted by said light emitting diodes. 14. An optical indicator system according to Claim 9 wherein at least two of said light pipes form a single unit and are configured to be mounted in said base as a single unit. 15. An optical indicator system according to Claim 14 wherein said light pipe apparatus comprises at least two single units of said light pipes. 16. An optical indicator system according to Claim 9 wherein said light pipes are molded from a clear plastic material.

Inventors: BOEHM THOMAS PATRICK, COMER JERRY WAYNE, HICKS BOBBY LEE JR, BOEHM, THOMAS, PATRICK, COMER, JERRY, WAYNE, HICKS, BOBBY, LEE, JR.
Applicants: GE FANUC AUTOMATION INC, GE FANUC AUTOMATION NORTH AMERICA, INC.
Application year: 2001
Main classification: G09F9
IPC codes: G02B6, G09F9