Applying HDTV Imaging Technology To Industrial Applications
- Friday, 01 July 2011
New high definition (HD) television cameras are being integrated into industrial environments to assist in the inspection of a variety of manufactured products. HDTV technology is reaching areas of application far outside the broadcast or entertainment markets, in part because of the capability of perfectly matching the cameras’ HD resolution, pixel to pixel, to high definition LCD and LED monitors, making these systems ideal for real-time, live viewing inspection.
Quality Control Inspection
One application utilizing the newest HD camera system involves the quality control (QC) inspection of circuit boards at an industrial manufacturing plant. The original QC process involved three inspection stations with the line inspectors looking through the eyepieces of stereo microscopes with typical magnification of 7x to 40x. Because the employees were required to wear safety glasses, this made viewing images through the microscopes even more difficult and often resulted in eye fatigue. The decision was made to remove the three microscope stations on the inspection line and replace them with the newest single-chip CMOS camera technology, e.g. a high definition, real-time camera system for each station, all connected to high definition monitors (Figure 1). Since the cameras and lenses are much smaller than the microscopes, they can be placed higher, allowing for more working space for the inspectors. The monitor can also be mounted slightly higher to keep it out of the way, and it can be shared with a local computer, if needed (Figure 2).
In addition to eye fatigue, which was remedied with the use of a high def monitor, alignment of a microscope system with its many parts (e.g., eyepieces, condenser, and lighting) can be difficult. Use of the HD camera system with one main component eliminates misalignment of the image.
Vibrations, which also present a challenge, are often caused by the weight of the microscope and/or the technician looking into it. Because the lightweight camera creates no vibration on the mount and the technician views the image on a monitor, these issues are also resolved with the HD system. Enabling the inspectors to view the live HD images on the HD monitors has improved the quality of the inspection dramatically.
The inspector’s physical comfort (not having to lean over to view through the microscope eyepieces) and the monitor being visible to everyone in the vicinity, sometimes even several lines away, has also contributed to an increase in quality control on the circuit board inspection stations. Further, the technician could easily point to a defect on the screen to a colleague, if collaboration was required. In this ongoing inspection process, the experienced inspection technicians are also using the HD system to “visually” train new personnel with live, real-time demonstrations on how to detect circuit board defects.
The circuit board manufacturer has employed the Dage-MTI HD-210D high definition single-chip CMOS camera, with a Navitar Zoom 7000 Macro-Zoom lens, a Schott-Fostec annular fiber optic ring light with polarizer, and a high definition monitor. The illuminator provided a uniform light source which eliminated the unwanted shadows from the circuit board while the polarizer used on the light source and camera lens prevented bright reflections from the solder pads and wire elements.
The solution for simple HD image archiving is achieved in this application by using the RV-DR capture device. One click of the mouse automatically labels and saves images to a USB memory stick, and a scroll of the wheel allows instant review of all the captured HD images.