Help Identifying LCD module (Images included)

Hi all,
Im after getting a hold of 4 LCD modules as part of a job lot. I was delighted when I found them, as the marking on the pack suggests that they could be used for a good few display applications: voltage, frequency, etc. However, I cannot find any datasheet or information regarding the parts.


As you can see in the pictures, the only marking on underside other than the pinout is "singapore". On the top part of the pcb, under the LCD, are the characters "OPCVO". Googling the name reveals nothing.

Does anybody have any other suggestions as to how i might go about getting a circuit diagram/datasheet for the LCD modules?

They aren't just LCD modules (almost all of which are based on Hitachi types).

They look to me to be digital voltmeter modules, but of a type I've never seen.

They usually have a standard range of 199.9mV the D1 etc. pins are to switch on whichever decimal point you want, the A, V etc. are to switch on annunciation letters in the dispaly (for amps volts etc.).

Here's a similar common type:

DPM 2000 | Panel Instruments