Gentex Corporation's product range, the process behind bringing these technologies to market, and what the company is planning in terms of future product developments
The first examples of auto-dimming rearview mirrors were electro-mechanical devices, meaning they featured automated operation of the manual anti-dazzle setting. A modern solution to this same problem are the electrochromic rearview mirrors produced by Gentex Corporation, which replace motorized operation with a considerably more advanced system.
Enoch Jen, Senior Vice-President at Gentex explains how the electrochromic mirrors work. “The system is activated when an electric current is applied to the coated glass, causing the mirror to change from clear to opaque.” The system is controlled by what is referred to as a complementary metal oxide semi-conductor (CMOS), a sensor which constantly adjusts the darkness level of the mirror based on the detected light strength. According to Jen, mirror reflectivity ranges from 87% to only 4%. Connie Hamblin, Vice-President of Investor Relations at Gentex explains the manufacturing process behind the mirror system. “The production line is split into two halves, the first dealing with assembly of the electrochromic element. First, the glass is cut to shape before being washed and dried. The glass parts are then placed in a vacuum coater where the rear sheet has a reflective, conductive coating applied. The other sheet has a transparent conductive coating. The pieces are then sandwiched together, with a seal around the outer edge. The space between the two sheets is about the width of a human hair. After curing, the pieces enter a vacuum chamber where the air between the two pieces is removed; as the vacuum is released, our proprietary electrochromic fluid is sucked into the gap. Once the valve is sealed, this is the electrochromic element.” The second part of the process involves production of the printed circuit board, as Jen explains: “We use automated insertion equipment to add hundreds of components into the circuit board. This includes capacitors, displays and customised feeds.”
While production of the electrochromic element uses robotic arms to pass units between the assembly stations, the line producing the circuit board uses a wholly different method. “Operations on the electronic assembly line are carried out on a conveyor, which carries the board until it is fully populated. The automated equipment can add the smaller components, but we still have to manually insert some larger elements by hand. The other manual operation is where we marry the two elements together. We have handling equipment, but it still requires operators.” With regards to the production equipment, Jen states that it is all proprietary to Gentex. “The two main reasons we’re the low-cost producer of these products are that we’re integrated and we treat our equipment as trade secrets.” He adds that the equipment used in production on the glass portion of the line is all built to specifications delivered by Gentex. For assembly of the circuit boards, half the equipment used is ‘off the rack’ while the remainder is similarly customised machinery. Changes to the equipment are carried out by the relevant manufacturer. “We started working on the electrochromic mirror in the late 1970s and introduced the first model in 1987,” says Jen. “We had to develop the expertise in-house and from the ground up.” He adds that most of the robotics and the vacuum deposition process was developed by Gentex.
Like an automotive assembly line, production over the two main production lines is subject to on-going analysis in order to improve efficiency. “Our CEO, Fred Bauer, supports standardised work processes and instruction. We measure process timeframes and balance the line as much as we can in order to eliminate bottlenecks,” says Hamblin. Having developed the first electrochromic products, the company also had to design its own testing equipment, a process which Hamblin says is also the major cause of production bottlenecks.
“When you develop something new like this, you really have no choice but to develop your own (equipment)," he adds. "We’re always looking for ways to improve our test capabilities, while also improving throughput of our test equipment so that we do not have to build up any subassemblies along the production line. Every operator on the line has the authority to stop production if they detect any type of error or malfunction”
CMOS production and application
The CMOS sensing technology is the primary driver of the electrochromic rearview mirror. In various other forms, the sensors also drive numerous other products manufactured by Gentex. Originally licensed from Photobit, based in Pasadena, California, the sensors are now produced by Gentex.
“We were planning to outsource (sensor) production, but while we found that there were a number of significant suppliers, primarily in Asia, all of them manufactured high volumes of consumer-grade product and we needed much lower volumes and automotive grade,” says Enoch Jen. “It was because of this that we had to develop our in-house (production) expertise.”
Connie Hamblin explains that production of the CMOS sensors starts with the delivery of silicon wafers made to Gentex’s own specification. The first step is to probe and slice the wafers, a process that must be carried out under a microscope to ensure quality and also due to the size of the chips, which Hamblin describes as being the same size as a pepper grain. Manufactured in various resolutions, the sensors provide the luminosity data on which the various Gentex systems operate. For the electrochromic mirrors, the sensors have only two pixels, but this is sufficient to measure light intensity from following vehicles.
Other products, such as the company’s SmartBeam technology, require additional chip capacity. Jen explains: “SmartBeam had its start back in the 1950s and ‘60s, when some Detroit automakers wanted an automated headlamp assist system. The light sensors used in those systems were not very sophisticated and they did not always perform properly. We looked at the CMOS image sensing technology and saw the possibility of developing a sophisticated light sensor that would be able to perform this automated highbeam control.”
According to Jen, development of the SmartBeam system, together with the required software and electronic interfaces, started in the mid ‘90s and lasted up until 2005. “We had to discuss design changes with automakers, including a manual override system. A ‘system active’ indicator also had to be included on the dashboard.” Gentex now manufactures 600,000 units per year for 51 vehicle models from OEMs including Audi, BMW, Chrysler, GM, Opel/Vauxhall, Peugeot, Rolls-Royce, Toyota/Lexus and Volkswagen.
The CMOS sensor driving the SmartBeam system is considerably more complex than that used with the electrochromic mirrors. “We call this chip an image sensor, as it’s really a low-resolution camera,” says Hamblin. “We bond microscopic wires to the chips to create a ‘lens’ and end up making a camera.”
Unlike a digital camera, which has millions of pixels on a CCD card, the CMOS sensors have thousands of pixels. Instead of collecting light in order to deliver a visible image, these are used to collect different types of light. “The difficulty we face,” says Jen, “is that we have to detect the difference between on-coming headlamps and tail lamps, which are a different colour and 1,000th of the brightness.” The sensors are further equipped to supply data that allows the system to differentiate between moving and stationary light sources, reflections from snow banks and road signage and even direct- and alternating-current light sources. “A certain number of pixels are dedicated to look for each of these light sources, which then determine ambient light and whether it is appropriate to turn your highbeams on or off. It is the sensor that drives the software which makes the decision on how the system actually works.” The SmartBeam sensor is located in the base of the rearview mirror where it is mounted to the windscreen. The data is collected by the same circuit board that drives the electrochromic mirror feature, which Jen says helps to reduce production costs. While the software works within its own microprocessor to deliver system decisions, the circuit board in the mirror is also connected to the bus of the vehicle, which delivers such information as vehicle speed. “OEMs don’t want the headlights to turn on if the vehicle is moving too slowly,” he adds. “Some have a speed threshold of 15 or 20mph.”
Enoch Jen explains why Gentex equipment is usually offered as a cost option for most vehicles. “Our strategy is (to offer) virtually all our mirrors and systems as options because that allows the automaker to see the technology as a profit generator rather than a cost adder.”
With regards to OEM vehicle assembly, Jen says that carmakers must make adaptations to vehicles that will feature these systems. This includes changes to the mechanical engineering and integration into the electrical system. Additionally, there must be switchgear on the instrument panel to activate and override the system, which are generally incorporated into the vehicle lighting controls. This accounts for the two- to three-year lead time before the features can be offered with a specific model, but as Jen points out, some models are easier to work with than others.
“The systems have to be tailored to individual automakers,” he says, “but between different carmakers there are great differences, particularly in the area of electrical architecture. For example, in North America, virtually every vehicle platform has a different electrical system. In Europe, there is a lot of commonization across vehicle models.” This, he continues, was a key driver behind the company’s recent announcement that it was to ship the system for 16 new Audi and Volkswagen models. “In the US, when we developed the feature for the Cadillac CTS and STS, they were two completely different development programmes. So while the development programmes are similar in length, once you develop it, you can extend it across a much larger number of vehicles in Europe than in most other parts of the world.”
According to Enoch Jen, development of the SmartBeam product took almost 15 years. That’s a long time for a product not to be earning any income, but he says that it helps understand how Gentex operates. “We’re not a typical auto supplier. We understand that new technology and new product is the lifeblood of the company. So at any time, we have a large number of new technologies and new generations of current technologies under development. When you look at our financials, our engineering R&D expenditure is significantly greater than a typical auto supplier.”
With regards to R&D, Jen says that new ideas can come from a variety of sources. “Customers come to us or we go to them, or it’s a joint effort, but we always run (new products) through a business justification analysis. We are always looking for proprietary technology and product; we’re looking for a sustainable, competitive long-term advantage. But we have to be confident that there will be a future market demand.” He points out that Gentex has declined various customer requests for new product development, simply because there was no supporting business case. Likewise, he says that the company develops a lot of new technologies that don’t make it to market as they don’t pass the business justification criteria. In all, Jen says that a primary goal for Gentex is the successful combination of technology and good businesses practice.
He continues by saying that is not simply a case of a project being given the green light as projected sales figures turn from red to black. “Our CEO employs a ‘rule of halves’ in order to define future (product) success. What this means is that every market you look at will be half the size, the development effort will be twice as difficult, and it will take twice as long to develop a final product. If you go through these steps to determine market opportunity, the potential market ends up being about 1/8th the expected size. In a lot of cases, that portion still represents a very large market.” Connie Hamblin emphasizes the overall goal at Gentex. “Quality is our number one objective. We make sure that there is a payback for automating, either in quality or in productivity. Michigan is home to our manufacturing, where we have a very productive, low-cost, non-union labour force.”
Company-wide, Gentex has approximately 2,800 employees, of which Connie Hamblin says 20% of which are engineers or PhD chemists. The workforce also comprises 1,800 hourly workers. “We have quite stringent requirements in terms of attention to detail and manual dexterity. We typically hire one out of every 20 candidates. As we have become more of an electronics company, we have had to increase the number of salaried people on the floor, technical team leaders and production engineers.”
Hamblin goes on to say that Gentex is centred around eight core competencies: micro-electronics, form level electronics, microphone development, design and engineering, chemical development, glass processing and coatings, automated assembly and vision systems. With these in mind, she explains that the company does not regard itself as an automotive supplier. Instead, it is a technology firm that develops and delivers automotive components.
While it is accepted that this is technology that just happens to be related to the automotive sector, the company is still marketing its products to companies notorious for cutting their own costs at the expense of supplier profit. Enoch Jen offers an overview of how Gentex deals with this pressure. “By developing new technology and new products, we can restart the pricing clock. Also, because we’re offered as an option, we can put forward the business case that if both we and they are correct, the consumer will pay for these features. As automakers typically add a considerable mark up to such features, they can make more than we do on our products.”
When it comes to resetting the pricing clock, Gentex is continuing to build on its core products; the mirrors are the bread, while additional features are the butter. Looking at future product developments, Enoch Jen says that the company will look to use these technologies in other areas of automotive development. “We’re looking at safety applications that involve other microelectronics, image sensor products, we well as electronic software algorithms. In other words, we’re looking at driver-assist features like SmartBeam and other features like lane departure warning and traffic sign recognition. Driver safety features using the technology we already have available.”
Hamblin says that these products will be available in three years, adding that the company is looking to hire additional staff. “We need software engineers, electrical engineers. We’re looking for support staff at all of our global offices.”