Help!! UV light golf ball detection

[Kendall]

Does anyone have experience using ultraviolet light to bounce off golf ball
surfaces to detect them at about one metre away? I'm seriously stuck at this
problem.... I'm using multiple ultraviolet LEDs as the light source and a TI
OPT101 light sensor for detection. I have access to lenses but they don't
seem to be much help

Or has anyone heard of the inner workings of Mike Ramsey's UV light golf
ball finder? I just appeared in the news in July this year.

A desperate student,
Kendall

 

[Frank Bemelman]

Does anyone have experience using ultraviolet light to bounce off golf ball
surfaces to detect them at about one metre away? I'm seriously stuck at this
problem.... I'm using multiple ultraviolet LEDs as the light source and a TI
OPT101 light sensor for detection. I have access to lenses but they don't
seem to be much help

Or has anyone heard of the inner workings of Mike Ramsey's UV light golf
ball finder? I just appeared in the news in July this year.

A desperate student,
Kendall

The sensor you have is tuned to infra-red, not ultra-violet. It won't
produce much output.

Also, you should modulate the UV led, switching it on/off at
10Khz for instance, and use an AC-coupled amplifier with a nice
gain (1000x, 10000x perhaps) and see what that gives you.

 

[Mike Harrison]

Does anyone have experience using ultraviolet light to bounce off golf ball
surfaces to detect them at about one metre away? I'm seriously stuck at this
problem.... I'm using multiple ultraviolet LEDs as the light source and a TI
OPT101 light sensor for detection. I have access to lenses but they don't
seem to be much help

Or has anyone heard of the inner workings of Mike Ramsey's UV light golf
ball finder? I just appeared in the news in July this year.

A desperate student,
Kendall

Why use UV ? IR would probably be easier, and cartainly give you a much wider choice of emitters &
detectors.

 

[Product developer]

What color is your background? Infra-red is the best way to go
depending on background reflection. With a simple filter you can zero
in on the target wavelength. You will want to chop or modulate your
source.

 

[Howard Henry Schlunder]

Your design problem sounds most fascinating. If I weren't tied up with my
own Ultrasonic Tracking System project right now, I would definately try to
make a golf ball detector.

Anyway, thinking about it, golf balls are usually white, and colored as
such, they may fluoresce a whitish-blue under UV LEDs, whereas grass will
not likely do anything. It seems to me that you might get good results if
you follow Frank's excellent modulation and AC coupling suggestions and then
use an optical filter to filter out all the violet light on your optical
receiver. As for your optical sensor, you might be able to get by using
another LED (probably another UV or Blue LED would work better than other
colors). If you reverse bias them, their leakage current should increase
when the right light color hits them. It might also end up working as a
scorpian finder as they happen to fluoresce as well under UV.

Howard Henry Schlunder

 

[N. Thornton]

Hi

If you need more uv output, try a small halogen bulb, with aluminium
as the reflector. Avoid glass optics, such as the glass fronted
enclosed reflector type bulbs.

Regards, NT

 

[Howard Henry Schlunder]

Wa? I thought pretty much all incandescent light bulbs are bad UV producers
but instead create floods of infrared. It's also my understanding that
glass transmitts UVA with relatively low attenuation (although highly
attenuates shorter wavelengths, like UVC), and therefore glass would not be
a primary concern in this application.

In message , someone
wrote:

 

[Kevin McMurtrie]

Wa? I thought pretty much all incandescent light bulbs are bad UV producers
but instead create floods of infrared. It's also my understanding that
glass transmitts UVA with relatively low attenuation (although highly
attenuates shorter wavelengths, like UVC), and therefore glass would not be
a primary concern in this application.

In message , someone
wrote:

Incandescent light bulbs produce a very broad spectrum. A xenon-halogen
bulb running at 120% voltage produces a good amount of UV.

Glass does kill the UV. That's one reason why halogen lamps must always
be shielded (other is fire/explosion hazard). The bulbs are made of
quartz, which doesn't stop UV.

 

[Howard Henry Schlunder]

in message

Incandescent light bulbs produce a very broad spectrum. A xenon-halogen
bulb running at 120% voltage produces a good amount of UV.

Glass does kill the UV. That's one reason why halogen lamps must always
be shielded (other is fire/explosion hazard). The bulbs are made of
quartz, which doesn't stop UV.

So is woods glass made out of quartz?

 

[Stepan Novotill]

You can get UV light emitting diodes. Just do a search on google.

 

[Kevin McMurtrie]

You can get UV light emitting diodes. Just do a search on google.

Not entirely; they're deep purple. One common use seems to be
fluorescence testing where the fluoresced color is at a lower frequency
than cyan/blue.