An update on TSAL5300 v.s. TSAL6400.

Based on the spec sheets, I think the TSAL5300 is actually a newer as well as a better part than the TSAL6400
bigger numbers aren't always better or all part numbers would be 99999999999 by now.

The 5300 actually has cleaner lensing than the 6400, so though it's only +-22 deg
v.s. the 6400 +/-25 deg, the 5300 will give more even illumination.

Look at Fig. 9 - Relative Radiant Intensity vs. Angular Displacement
here:  http://www.vishay.com/docs/81011/tsal6400.pdf
v.s Fig. 9 for the 5300
http://www.vishay.com/docs/81008/tsal5300.pdf

As far as intensity goes, the 6400 specs min typ max at  25 40 125 mW/sr
while the 5300 is  30 45 150 mW/sr  so 5300 is slightly brighter.

They are both 940 +/-50 nm so same wavelength

If you need wider angle you can flatten or rough up the LED
Flatten and polish you can get +/-50 - 80 depending on where you do it. (cut the top off square)
Roughing with sandpaper, even 600 grit, will just make the light scatter everywhere and make it dim.
You want wider angle and brighter? go with a VMSx nnnn where x is B F G S etc determining wavelength, and the number "nnnn" will give you some variation in brighness, they are all 100mA flat lens PLCC-2 package LEDs


G

is this correct? I should sand the casing of the led too correct?

Francisco,

I had not seen your comparison thread. Nice job documenting the pattern. Did you set the current the same on both LEDs?   It concerns me that many people are driving their LED straight from the battery, so have no idea what the current level is going to be. Too high with a fresh battery, and falling as the battery ages. There are lots of current source chips out now, but none of them are free. I wonder how much difference it makes if you drive LED correctly.
Here's a nice driver you can get in Europe:
http://www.ichaus.de/product.php?prod=iC-HK/iC-HKB
Here are some other choices:
http://www.fairchildsemi.com/whats_new/LED_nph.html
http://www.linear.com/pc/viewCategory.jsp?navId=H0,C1,C1003,C1094
http://www.semiconductor-sanyo.com/power_supply/topics/led-driver.htm
http://www.infineon.com/cms/en/product/channel.html?channel=ff80808112ab681d0112ab6b15d7070e

There are many more.  You can use two batteries and a resistor, but that just seems wasteful to me, and isn't really constant current, just better than one unregulated cell.

I'm working on an IRpen with two or more LEDs. Soon you will see why this is a good thing.

Gavin

Just file it flat and then polish it to clear. There is no reason to try to make concave, and you couldn't polish it anyway.

If you want a nice small flat LED, try the VSML3710 (940nm) VSML3700 (950nm) or any of the others in this family that strike your fancy and are available (VSMxn7nn).  They all can take 100mA continuous, and provide a 120 degree viewing angle, various colors and efficiencies.  I use it for my "Back" LED that is turned on with the finger switch for zooming, panning, and rotating. This LED is mounted at the back end of the pen.

I still use the T1-3/4 LED (TSAL5300 or 6400) for the tip LED as it is round and smooth and easy to actuate with tip pressure (spring load the lead mount about 1 mm from the battery terminal).  Just sand it lightly so the whole tip will glow from any angle (use a camera to view). If you are working on an IR reflective surface you don't need to do anything as the beam out the front of the LED will scatter and bounce back to the camera.  I'm giving too much away, but I don't have time to commercialize on it so I guess I'll just give it away ;-)

Gavin