Idea - Laser phosphor bulb

[jden]

Hi, very new here, it seems like you guys aren't very happy about the LED situation, and I thought I came up with a clever idea.
At the base of the bulb is a blue laser which emits light down a fiber optic tube, coated in an opaque coating to not allow light through the outside. At the end, it forms into a conical tip covered in phosphor, so similar to a pencil, where the paint is covered and the wood is the phosphor coating. Conical rather than cylindrical to allow all the blue light to be converted into white light. The dimensions of the conical tip would be exactly that of a halogen filament. Color would be determined by phosphor coating, type of laser, etc to suit different tastes. The conical tip would emit white light in all directions, and the entire assembly of the bulb could be covered in glass exactly like a halogen bulb. With the emitter being the exact dimensions as a halogen filament except being conical rather than a cylindrical coil, it should emit light in the same way, right?

 

[Hamilton Felix]

Production cost?

 

[-Virgil-]

Hi, very new here, it seems like you guys aren't very happy about the LED situation

It's beginning to improve. We are at the early stages of LED retrofit bulbs, from reputable makers, that actually work well in some halogen headlamps.

Your idea has a lot of problems and issues. First of all:

At the base of the bulb is a blue laser which emits light down a fiber optic tube, coated in an opaque coating to not allow light through the outside.

It's been done. Four or five years ago at the Driving Vision News event in Detroit, Morimoto/TRS showed prototypes meeting this description. I don't know what (if anything) they've done as far as development goes since then.

At the end, it forms into a conical tip covered in phosphor, so similar to a pencil, where the paint is covered and the wood is the phosphor coating. Conical rather than cylindrical to allow all the blue light to be converted into white light. The dimensions of the conical tip would be exactly that of a halogen filament. With the emitter being the exact dimensions as a halogen filament except being conical rather than a cylindrical coil, it should emit light in the same way, right?

Everything about this is...not in line with reality. There is no such thing as a cone that is dimensionally the same as a cylinder. That's like saying an orange with the exact same dimensions as a garage door spring; it's just completely self-contradicting. No, it will not "emit light in the same way". Optics that are designed for a cylindrical light source must have a cylindrical light source in order to produce the intended beam distributions. This is one of the fundamental reasons why "HID kits" don't work: the HID light source is shaped like a curved line or a crescent, rather than a cylinder.

Also, there is no such thing as "all the blue light converted into white light", regardless of the shape of the phosphor-coated surface. Phosphors do not convert blue light to white light, they convert blue light to polychromatic yellow light, which mixes with the blue light to create a white.

the entire assembly of the bulb could be covered in glass exactly like a halogen bulb.

Why? The reason why halogen and HID bulbs have a glass capsule is to maintain a specified atmosphere inside the capsule so that the light source works. That's not necessary with LEDs or with this remote-phosphor setup you're describing, so all a glass capsule would do is reduce output and add stray light because of reflections.

 

[idleprocess]

You've basically described laser headlights as they exist now, except like LED headlights they're tightly integrated sealed assemblies featuring optics, driving electronics, housings, electrical connectors. More broadly, you've described Laser-Excited Phosphor, of which Weltoool seems to be one of the present leading brands for flashlights.

 

[-Virgil-]

You've basically described laser headlights as they exist now

Well...not really, no, not beyond the use of a laser to excite a phosphor. This light guide/conical end stuff is nothing like (real) LARP headlamps. The way those work is to point a laser diode at a phosphor plate, to create a very high luminance, very small, very sharply-defined dot of light. That dot is used as the light source for the headlamp.