Market analysts frequently point out that there is an ever-increasing demand for digital data storage. This is great news for Flexon Technology, a Bangkok-based integrator that serves manufacturers of cases for hard disk drive (HDD) data storage devices.

Each HDD device features one or more rapidly rotating disks that are coated with magnetic material and effectively store digital information for later retrieval. Increased production of these devices has lead to a greater emphasis on quality control. This is due primarily to the increasing complexity of the devices, as well as the need for manufacturers to meet their customers demand for higher product quality with a shorter lead time.

Once manufactured, an HDD is carefully fitted and sealed in a metal or plastic case. The case ensures that all drive components are perfectly secured in place and their mechanics work well over the lifetime of the product. It also protects the sensitive disks from dust, humidity, shock and vibration.

An HDD case must be defect-free and have perfectly machined thread holes to perform these functions, according to Somporn Kornwong, a manager at Flexon. In 2019 his company developed Visual Machine Inspection (VMI) for a manufacturer so it can quickly and thoroughly inspect each case it produces.

Within each VMI are two vision stations. The first station has one Mako G-125B and Manta G-505 GigE camera made by Allied Vision Technologies Inc. There are four cameras in station two: three are Mako and one is Manta.

During operation, each HDD case is loaded onto a conveyor and moved to vision station one. Here, the Manta camera ensures that the case is in the proper location for inspection. The Mako camera then takes 14 images (within 4.2 seconds) of the top part of the case. Photo-analysis software quickly checks for proper threads, thread quality and machined surfaces.

The case is then flipped over and moved to vision station two. There, two Mako cameras inspect the sides of the HDD case for missing or incomplete threads.

Another Mako camera inspects the back part of the case for any incomplete threads; missing threads or rivets; and incomplete or improperly machined surfaces. It also reads and verifies the case’s part number.

The other camera, a Manta model, locates and verifies the presence of a thread hole on the case’s bottom edge. Cycle time in this station is 4.8 seconds.

If the case passes inspection at both stations, it proceeds to the load-out conveyor. Any case that fails either station inspection goes into the rejected pile.

Both Allied Vision cameras utilize power over Ethernet and offer high frame rates. The G-125B combines a Sony ICX445 CCD sensor with EXview HAD technology. At full resolution, this camera runs 30.3 frames per second. With a smaller region of interest, higher frame rates are possible. Its high image quality is due to the precisely aligned sensor.

More compact and economical is the Manta G-505B, which incorporates the Sony ICX625 CCD sensor. At full resolution, this camera runs 15 frames per second. Other features of note include three look-up tables, color correction capability, a robust metal housing and many modular options.

For more information on machine vision cameras, call 484-881-3398 or visit