Hi Source,
It is too bad that you didn't post your request in our Datasheet Request forum. I use a few sites to find datasheets. This is from one of them:
http://www.datasheetarchive.com/semiconductors/download.php?Datasheet=2051883
That chip is a combination of a light photodiode and current to frequency converter. Too bad it is not available. It would make things a lot simpler. There are many other applications for your Numeric displays. You might find some application assistance from TI. Sometimes they have application notes on their site.
Sorry for the confusion. I sometimes assume everyone knows certain things. TI is the abbreviation for Texas Instruments (the manufacturer of the chips). You can access them at http://www.ti.com on the internet. Hope it is helpful.