DAQ Application: Laser Measurement | GaGe

Test & Measurement Application Case Study - Data Acquisition Video Testing / Optical Imaging

Test & Measurement Applications

Laser Measurement & Characterization of Flat Panel Displays

Customer Case

This customer's application involves the characterization of flat panel displays (used in laptop computers, computer game displays, etc.) via laser scanning. The laser is bounced off a number of mirrors and then through lenses, from which it is scattered. The scattered laser light must then be analyzed in order to determine the quality of the flat panel display.

This laser measurement system is used not only by flat panel display industries, but also by disk drive manufacturers to analyze platter quality and, in the near future, for characterizing silicon wafers (used in microprocessor manufacturing) as well.

In this application, the glass substrates of the flat panel displays are laser scanned. The linear scan is 340 mm in length, with approximately 50 points per millimeter. The customer would like to scan at least 6,000 of these lines to memory and then analyze the captured data. The current sampling rate is 25 MSPS on one channel.

GaGe Case Solution

The scanned lines of data are coming in at a frequency of 2 KHz, or one line every 500 us. Since the customer needs to scan a total of 6,000 lines, they must capture for 6,000 x 500 us, or three seconds. The sampling rate is 25 MSPS for three seconds, so a total of 75 Megasamples of data will be captured. However, because the data is 12 bit (two bytes per sample), the customer will need to store a total of 150 Megabytes of data in memory.

GaGe recommends the CompuScope 6012/PCI and the MMD 5400 for this application. The unique architecture of the CompuScope/PCI cards allows data to be captured line-by-line in Real Time mode, and streamed to any PCI bus target at high speeds. MMD 5400 is a PCI bus memory board which can be used by a CompuScope/PCI card as a target device. It is capable of housing up to 512 Megabytes of high-speed DRAM.

For this application, the 512 MB version of the MMD 5400 would be ideal, because the customer would no longer be limited to 6,000 lines of data at 25 MSPS. The extra memory space permits even longer scans and higher sampling rates for greater resolution. The CS6012/PCI will also allow the customer to increase the sampling rate if they decide to take advantage of the increased memory storage capabilities.

The CS6012/PCI card and MMD 5400 card will require two PCI slots and one ISA slot in the customer's PC. Since the customer's present PC has no free slots, a GaGePC/PCI 580 also forms a part of this solution, providing two free ISA and three free PCI slots in an instrument grade PC.

GaGe Case Recommended Products

  • GaGePC/PCI 580-Instrument Grade PC with Two Free ISA and Three Free PCI Slots
  • CompuScope 6012/PCI-12 bit, 60 MSPS A/D Card for PCI Bus
  • MMD 5400-512-Memory board for PCI Bus with 512 MB Capacity

Test & Measurement Application Request

We encourage you to contact us and discuss your test & measurement application in more detail with our engineering team. GaGe can provide tailored custom data acquisition hardware and software solutions to meet specific application requirements.