Can Anyone Identify this Optical Sensor?

[Athar Rasul]

Hi,

I need help in identifying the optical sensor (pic attached). It is a DIP8 package and there is nothing written/embedded on its case. Apparently it is an ambient light sensor array or photo diode array. Hell, it could even be color sensor. I need to know the make and model of this sensor. Please help!! Any educated guess would be appreciated.

 

[DeboraHarry]

Hi,

I need help in identifying the optical sensor (pic attached). It is a DIP8 package and there is nothing written/embedded on its case. Apparently it is an ambient light sensor array or photo diode array. Hell, it could even be color sensor. I need to know the make and model of this sensor. Please help!! Any educated guess would be appreciated.

You could check if it contains photodiodes with a DVM, though there is a very slight risk of damaging it doing this, as you will need sufficient voltage to turn on a diode.

If it's designed for wavelengths much longer than visable, then the diodes will not be silicon, as the band gap would be too high in silicon. Germanium will respond to much longer wavelengths.

if you get it under a microscope, there is some chance you will see a model number. At one time it was fairly common for companies to strip the number off of ICs to make reverse engineering more difficult. But I know people who have found out what a device is by dissaembling it and using a microscrope. You have the advantage here the package is likely to be fairly transparent.

I doubt it is a colour sensor, though I expect one could make a colour sensor using 3 different filters (e.g. red, green and blue) in front of 3 different photodiodes. You might considering a Google to see how the colour temperature compensation is calculated in cameras. I know my camera, which is a professional model (Nikon D3), allows one to determine the colour temperature by first pointing the camera at a white or gray card. I imagine that is a more accurate method than trying to determine the colour temperature by looking at a coloured scene.

Certainly for me, the first thing would be to look under a microscrope.

 

[Athar Rasul]

You are right. It should reveal helpful details under a microscope and that's what I would've done if I had a microscope handy. One thing is for sure, it is designed for visible light because there are a lot of light tubes near its housing and it is used to differentiate white objects from colored objects at very high speed. DVM could be useful if it had a single diode and the pins would lead to it but I'm afraid it consists of an array of elements (photodiodes?). It has to be something like the Light-to-Voltage or Light-to-Frequency converter ICs that TAOS(AMS) and some other companies make. I'm going through the datasheets of TAOS. Hopefully something will come up (if I'm lucky and this isn't a custom-built IC).

 

[FvM]

It looks like a linear sensor array, but apparently none of the taosinc or ichaus standard types. You would want to check if this guess is true and determine the element count and size under a microscope. A color sensor would have clearly detectable filter sections.

 

[DeboraHarry]

A color sensor would have clearly detectable filter sections.

I would tend to agree, though potentially there could be a diffraction grating in front of an array of photodiodes to measure wavelength.

 

[FvM]

though potentially there could be a diffraction grating in front of an array of photodiodes to measure wavelength.

The operation principle of a diffraction grating involves considerable distance between grating and spectral image. And most practical gratings are reflective.

 

[sky_123]

I'm not sure, but I think it looks like the old TI (TAOS) linear arrays from maybe 10 years ago, I once had a few that looked like that (see **broken link removed**).

 

[FvM]

Yes, that's it, even the lead frame shape. I knew, that I had seen it before. But Taos has abandoned the DIL package option of TSL201.