This month we are kicking off a five-part blog series on backlighting. The series will begin with an overview of how to approach a backlighting project and each subsequent blog will review one of the four most popular backlighting technologies: discrete LEDs, light guide film, fiber optic weave, and electroluminescence.
Why should you be thinking about backlighting?
Backlighting has become an industry standard to augment the functionality and aesthetics of a device. From home appliances to aircraft cabins, and car dashboards to industrial controllers, backlit devices and accents are becoming increasingly ubiquitous. Backlighting is a simple way to improve visual appeal, enhance the user experience, and lend a distinctive style to your user interfaces. It can assist and guide users towards the correct operation of a device, especially in dimly lit and dark environments. It also provides vital feedback about user actions and interactions.
How to determine the most optimal backlighting solution?
Designers and product development teams often wonder when the right time is to start thinking about backlighting when developing new products. Ideally, backlighting should be considered at the very beginning of the design phase. This gives you the flexibility to evaluate available technologies and allows engineers to integrate backlighting seamlessly with the other technologies and features of the design.
To establish the best backlighting solution, the first step is to create a list of requirements and assess the proposed design. Start by asking these questions:
- What environment will the device be primarily used in - indoor or outdoor?
- Will the device be primarily used in ambient light, bright sunlight, or dimly lit spaces?
- Do you want to light up a small indicator window or backlight large areas like texts and graphics?
- How many colors do you need?
- Will all the areas be lit at once or do they need to be independently controlled?
- Are there any buttons or snap domes that need to be integrated into the design as well?
- What power type is available – is it a portable unit or a plug-in?
- What are the cost constraints?
Backlighting design concerns and considerations
Based on the responses to these questions, you should be able to evaluate which backlighting solution or combination of backlighting solutions could work with your device. Once you have evaluated and selected the most appropriate technology, you need to address all the design concerns and challenges that the technology presents. A few parameters to address include –
- Will the light source create hotspots? If yes, how can they be mitigated?
- Will the light bleed from one section to the other? Do I need a light-blocking layer?
- Is the construction stack-up too thin or too thick for the design?
- Is the backlighting affecting the tactile feedback of the buttons or switch technology?
- What brightness level does the design demand?
- Should the light source be mounted on a printed circuit board or printed membrane?
- What are the minimum and maximum sizes of the light source that can be used in the design?
- How many light sources do I need?
It is the interplay of several factors that ultimately dictate and influence the design, each of which is important when examining the cost structure of the project. While this is not an exhaustive list of design considerations and concerns, it provides a framework to effectively begin to approach your backlighting project by forecasting design hurdles and addressing them promptly.
To dive deeper into the four most popular backlighting technologies, read our other blogs in this series -
In a recent blog post, we discussed what optical encoders are and how they are used. Simply put, an optical encoder is an electro-mechanical component for measuring position, velocity, and acceleration. GMN’s optical encoders have been used for years in printers, scanners, medical equipment, and much more. Lately, our optical encoders have found an exciting new application as a vital component in LiDAR (light detection and ranging) sensors for autonomous vehicles.
What is a LiDAR sensor?
Originally developed in the 1960s for military use, LiDAR sensors use lasers to survey an area and create a 3D representation. They allow for highly accurate readings of distance and motion around the sensor and are commonly used for robotic and artificial intelligence applications.
A LiDAR sensor works by rapidly emitting pulses of light, which bounce off any surrounding objects and return to the sensor. The sensor then calculates the distance from each object in real-time, providing a three-dimensional representation of the surrounding area.
Recently, LiDAR technology has found its way into autonomous vehicles to aid navigation. Typically, the sensors are adhered to the top and sides of a vehicle, allowing a connected computer to have reliable environmental perception and to navigate terrain safely in real-time.
How do optical encoders make this possible?
GMN’s optical encoder disks are placed within each sensor, allowing them to accurately gauge position and rotation when the sensor emits pulses of light. Having accurate positioning is crucial for autonomous vehicles, as any error in calculating position can result in inefficiencies or accidents. Most notably, this is used for navigation by analyzing the 3D rendering around the vehicle and adjusting movement accordingly to avoid obstacles. They’re also used for modifying speed to keep safe distances from other moving objects, and to alter course to reduce the severity of an accident should it be unavoidable.
LiDAR sensors are a versatile technology where new applications are frequently being found. Currently, they are used to gather data and create models in a wide variety of industries including agriculture, manufacturing, and forensics. GMN is excited to provide a crucial piece of this exciting technology. To find out more about optical encoders and their many uses, take a look at our capabilities page or reach out to our technical experts for a free consultation.
When designing an electronic product, one important consideration is preventing unwanted substances from getting inside of the device. While internal components are typically protected by the main enclosure, any openings related to buttons, switches, and/or screens on the user interface can potentially allow for ingress of dust, liquids, and other substances that can cause possible damage or malfunction.
Fortunately, there are several methods to control, mitigate, and even eliminate liquid and particulate ingress. Below, we’ll be going over a few of the most common sealing methods.
What is sealing?
Liquid, chemicals, and dust can find their way inside of a product at any point where components meet. Sealing is the process of shoring up these connection points or openings to ensure undesired liquids or particles don’t affect function. But what are key considerations when it comes to sealing?
One of the most important factors when deciding on a type of seal is the level of protection required. In many industries, being able to withstand harsh environments or heavy cleaning while staying functional is paramount to the success of a product. For regulated industries, electronic devices often need to meet certain standards for the ability to resist liquids, chemicals, and other particles. Standards such as the National Electrical Manufacture Association (NEMA) 250 rating and Ingress Protection (IP) ratings per IEC EN 60529 are commonly used to define ingress requirements.
Another important consideration when designing sealing for a part is the amount of physical space available, as enough room is needed to achieve the required sealing. The look of a part can also play a large role here, as any visible sealants or adhesives may need to meet aesthetic requirements.
The overall construction of the part can dictate the sealing method as well. Sealing methods involving elastomer are generally only used on parts that are already committed to an elastomer construction, while a perimeter adhesive seal may only be viable for other constructions.
Common types of sealing methods:
- Perimeter adhesive sealing: One of the most common methods of sealing, this involves using an adhesive to adhere a graphic overlay to the front of the component. The adhesive goes completely around the perimeter underneath the overlay, preventing any liquid or chemical ingress. Because it requires a specific amount and type of adhesive for an effective seal, the available space on the bezel and under the overlay is an important consideration. Also, any other functional layers underneath the graphic overlay need to be accounted for in the sealing design.
- Front surface sealing: If there are any gaps or areas in which there can be potential for ingress on the front of a bezel or case, front surface sealing can be an effective option. For this method, a sealing compound is dispensed into a gap around any areas in which particulates or liquids could enter (typically the part perimeter). While this provides an effective seal, the sealant is typically black and cannot be matched to other colors, so it may not work with all aesthetic requirements.
- Rear surface sealing: Similar to front surface sealing, rear surface sealing seals off any openings around tails or cables that come through the rear housing of the device. Because the sealant is added to the back of the case where it generally can’t be seen, this is a good option for any device where there might be stringent visual requirements on the front. Many devices are designed with this in mind to avoid aesthetic issues.
- Front surface compression: Similar to a television remote, the elastomer rises through the bezel or case to seal off openings. The elastomer is molded to be compression sealed to the front of the part and offers a high level of protection from liquids and chemicals. As the seal is fashioned out of molded elastomer, usage of this sealing method is contingent on elastomer being an integral part of the product design.
- Wrap around elastomer: As shown in the image, with this sealing method, the silicone rubber keypad is molded to wrap around the edge of the part, sealing off the front and edges of a device. While this offers a high level of protection for internal components, like with front surface compression sealing, it requires a part where elastomer is already part of the design. Due to the use of compression molded elastomer, this undercut feature can generally be tooled and produced with little to no added expense.
Ultimately, choosing the most optimal sealing method comes down to the specific requirements of the project. To discuss which sealing method is right for your next product, schedule a consultation with our experts.
As printing equipment continues to evolve and become more efficient, it’s important to stay ahead of the curve. Always quick to embrace the latest technology, GMN’s Monroe, NC facility recently installed a new, cutting-edge digital press. Adding to the already vast array of printers and presses among GMN’s divisions, the new digital press is a perfect match for the wide variety of components manufactured at GMN.
GMN’s new digital press
The new press uses a unique flexible ink system, allowing it to print on a wide variety of materials including metals, plastics, acrylics, and roll labels. These substrates can even be formed and embossed after printing without affecting print quality. With a large print bed, it can easily print on substrates up to 5’x8’.
Being fully digital, the printer is ideal for multi-color jobs. Jobs that would have previously taken several color screens or passes can now be printed just as vibrantly in a single run. The press can also print translucent colors and varying tint levels, so brushed aluminum and other decorative finishes can remain visible underneath printed artwork. Variable speed and quality levels make this printer a versatile and cost-effective option for a variety of projects.
How does it compare to other printing methods?
Setting up for off-set lithographic or screen printing can take several hours with the preparation of art, plates, and screens. With the new digital press, all that’s required is a digital file, so a similar print quality can be achieved with significantly faster set-up times. Due to the large print bed, multiple sheets can run simultaneously, heavily cutting down on lead times.
The quick set-up also allows GMN to develop prototypes faster than existing printers. The press can quickly and effectively accommodate different colors, backgrounds, and even substrates, making it ideal for numerous applications and new projects.
The latest digital press is a great addition to Monroe’s arsenal of printing capabilities. As technology continues to evolve in the printing industry, investments like these allow GMN to keep providing unique and high-quality print solutions to our customers.
Lithographic printing, an offset printing technique, is based on the basic principle that oil and water do not mix. It is a process in which ink is transferred from a photographic plate to a rubber blanket, which then presses the image onto the printing surface.
Off-set lithographic printing process
The first step in lithographic printing is creating the artwork on a photographic plate through a chemical process. Similar to the process of developing photographs, lithographic printing also requires the creation of a “negative” and a “positive” image. First, a thin aluminum plate is coated with a hydrophobic material so that it attracts oil (ink) and repels water. The plate is then selectively exposed to light, thereby curing the hydrophobic coating only in areas comprising the artwork. Finally, the coating from the remaining areas is chemically stripped off and the plate is ready for use.
The lithographic printing press consists of a series of rollers laid next to each other. The foremost roller transfers water, placed in a tray beneath it, to the photographic plate. The ink is manually applied to the second roller with a putty knife, which then wets out to the entire cylindrical surface as the roller spins and transfers the ink to the plate. The photographic plate, carrying the artwork, is wrapped around the next roller in the series. Given the immiscibility of ink and water, the ink adheres only to the artwork on the photographic plate, while the water adheres only to the remaining background.
On the other side of the photographic plate are two other rollers called the blanket roller and the impression roller respectively. The blanket roller simply acts as a medium to transfer the artwork from the plate to the substrate. When printing, a stack of printing sheets is placed on the top tray of the machine. A gripper grabs one sheet at a time and wraps it around the impression roller. The artwork on the photographic plate is imprinted on the rubber blanket roller, which in turn transfers it to the substrate on the impression roller. Then, the ink is cured by exposing the printed sheet to UV light. The process is repeated for every unique color in the image.
Advantages and disadvantages of lithographic printing
Ideal for high-volume manufacturing, a lithographic printer can run from 3,000 to 6,000 impressions per hour, with the largest sheet size being 18”x24”. It can produce detailed and intricate artworks with half-tones, gradients, or a four-color process (a four-color process uses a CMYK color module to create four separate dotted patterns, which when printed on top of each other, yield the required color). However, lithographic printing comes with its own limitations. It can only accommodate substrates with thickness ranging from 0.003” to 0.020”. The printing system is not compatible with metallic or conductive inks. Also, the ink used is very transparent, and typically requires extra layers of printing for opacity.
Off-set lithographic printing services at GMN
While lithographic printing is often performed on standard substrates such as paper and vinyl, GMN walks the unbeaten path by predominantly using materials including polycarbonate, polyester, and aluminum. Allowing for extremely tight tolerances and consistently high-quality images, GMN’s sheet-fed lithographic process is frequently utilized for printing graphic overlays and labels.
Lithographic printing at GMN utilizes UV-cured inks. GMN also offers custom color matching services to help customers achieve their exact specifications and uphold brand consistency. To formulate a custom color, the different colored inks are meticulously weighed, poured over a flat glass surface in carefully measured proportions, and mixed together using a putty knife. With projects requiring custom color matches, a small sample sheet is first tested on a machine called the orange proofer. This counter-top machine is simply a condensed version of the actual printing press, that allows GMN to test the color and make necessary alterations before the final production run.
Printing solutions at GMN
As multiple factors go into consideration before selecting a suitable printing technique, GMN works closely with each customer to understand the project needs and requirements to determine the best printing solution for every unique application. To learn more about our flexo, screen, and digital printing technologies, visit our blog on GMN’s printing capabilities. To kick-start a discussion with a GMN expert, request a free design consultation.
Although optical encoders are found in a vast number of products across multiple industries, few people know what optical encoders do or what products use optical encoders. Even in the manufacturing industry, many are either unfamiliar with optical encoders or do not know how often they are used in everyday machines and equipment.
An optical encoder is an electro-mechanical component with a precisely printed line pattern that is usually paired with an optical sensor to measure motion, such as position, velocity, and acceleration. Mounted between a light source and a photodiode sensor, the photodiode reads and counts the lines on the optical encoder which tells the device where it is or when, how, and where to move. There are two types of optical encoders as follows:
- Disk or ring encoder – Used to measure rotation
- Strip or linear encoder – Used to measure linear motion or speed
Materials for optical encoders
According to the temperature resistance and accuracy requirements of different equipment, optical encoders can be manufactured using metal, glass, polycarbonate, or polyester film, with each material having different advantages, drawbacks, and varying degrees of cost competitiveness. For instance, metal encoders are highly durable and can withstand high temperature, humidity, and shock, but come with certain limitations when it comes to corrosion.
Applications for optical encoders
Optical encoders are not only used in inkjet printers and laser printers, but also seen in a variety of applications including medical pumps, scanners, sunroofs, memory seats, car speedometers, and encoder modules.
The world of robotics also heavily relies on optical encoders to automate movement. In recent times, several automated operations such as robotic transportation of raw materials, material handling, and assembly have emerged in the manufacturing industry. Optical encoders are a significant contributor to the robot’s ability to flawlessly perform the coded operations. All automation devices need to measure position, acceleration, or velocity and require optical encoders to measure this motion. As automation grows, we will continue to see optical encoders employed in more equipment.
Need a custom optical encoder?
As one of the leading manufacturers of disk and strip encoders, GMN ships millions of encoders every month to leading companies such as Epson, HP, and Avago Technologies. Visit our capabilities page to learn more about optical encoders or connect with one of our technical experts for a free consultation here.
When a California-based medical company was assembling its new infusion pump, they knew it was critical for every part to work perfectly and be free of defects. One of the most important parts was a custom rear housing that encases all of the internal components of the device. Having worked extensively with GMN in the past, they knew they could trust our team with the production of this vital component.
The housing was complex, featuring an injection-molded plastic casing, 15 separate brass inserts, electromagnetic shielding, and a latch closure. While each component was inspected at various stages of the production process, given the complexity and the assortment of components involved, it was still possible for an issue to be overlooked. While it was rare, this occasionally resulted in a defective part making it through to the next phase of production, where it would be flagged and removed from the production line. Upon further analysis, it was discovered that these occasional defects stemmed from the improper positioning of the brass inserts. Even a single missing or misaligned insert could cause issues during assembly.
To resolve this issue, the experts at GMN decided to implement a custom vision inspection system. This vision system would automate part of the inspection process, lowering the total possibility for error as well as making the production process more efficient. After some experimentation, the team ultimately decided to integrate the inspection system directly into the heat stake where the brass inserts were positioned and inserted.
The vision system consisted of two cameras located directly above the platform where heat staking took place. This allowed the system to verify the presence and proper alignment of all the brass inserts before being injected into the assembly. As a secondary measure, the vision system checked the alignment of the inserts after they were heat staked into the housing.
After adopting the vision system, the defect rate dropped to nearly zero. It significantly reduced the production time, allowing more defect-free parts to be fabricated in the same time frame. The vision system has earned a permanent place at GMN’s Beaverton, OR plant to uphold the quality of the infusion pump housing.
This is just another example of GMN leveraging custom technologies to enhance the quality of its products and improve manufacturing processes. To find out how GMN can help with your next product, request a consultation with our experts.
When developing a user interface, it’s important to consider what the user needs to see during an interaction. For certain applications, calling attention to an indicator or warning light while keeping others hidden can be crucial. For situations where eliminating distractions, keeping a clean aesthetic, and emphasizing certain switches or indicators is imperative, look no further than dead front printing.
What is dead front printing?
Dead front printing is the process of printing alternate colors behind the main color of a bezel or overlay. This allows indicator lights and switches to be effectively invisible unless actively being backlit. Backlighting can then be applied selectively, illuminating specific icons and indicators. Unused icons stay hidden in the background, calling attention solely to the indicator in use.
Printing methods and substrates for dead front overlays
There are two ways to illuminate a dead front overlay, each of which requires a different printing approach. The first method is to use LEDs directly behind each indicator or icon. This approach simplifies the printing process (since LEDs provide the colors, the printing generally employs a single color behind each button). Alternatively, different translucent colors can be printed selectively behind various indicators. With the use of translucent colors, almost any backlighting method can be used since it’s the ink behind the iconography that gives the indicator its hue.
Diffusers are often applied behind the lights to maintain consistency throughout an overlay. Particularly with LEDs, diffusers can help eliminate hotspots, where one part of the letter or icon appears much brighter than other parts. Once a part is ready, a standard is made, so any future overlays or alterations are readily available and can easily be matched to the standard.
While dead front printing is technically possible with almost any colored bezel or overlay, it’s generally seen on overlays and bezels printed with neutral colors. Typically printed on polycarbonate, polyester, or glass, colors such as white, black, or gray tend to hide unused indicators the most effectively.
Developing dead front control panels with GMN
When developing a new dead front overlay, experimentation is often necessary to get the perfect look. Given the breadth of possible lighting options, ink densities, color palates, and substrates, maintaining a consistent look across an overlay often requires several prototypes to be developed. At GMN, we have a state-of-the-art color lab, a light lab, and a full printing team that works in tandem to match and perfect colors. Within our color lab, spectrophotometers and spectroradiometers are frequently utilized to get specific color values necessary for matching. Our light lab will then work with the printing team to narrow down the exact mixture and density of ink necessary for the specific substrate and required look.
Dead front printing is an excellent option for a wide variety of applications such as automotive dashboards, aerospace indicators, and touch user interfaces. Want to learn how dead front printing can help your product be more efficient while ensuring a clean aesthetic? Watch the video below and schedule a consultation with our experts.
In our previous blog, we talked about the different kinds of resistive touchscreens and how they compare. While resistive screens offer a high level of versatility, another one of the most widely used touchscreen varieties is the projected capacitive touchscreen. Below, we’ll be discussing the key features and advantages that make projected capacitive technology such a popular touchscreen option.
What are projected capacitive (PCAP) touchscreens?
In contrast to resistive touchscreens, projected capacitive touchscreens don’t require any physical pressure to activate. Rather, they rely on projecting a capacitive field through the display. This field is then disrupted by electrical impulses from the human body when the cover glass is touched. PCAP touchscreens have grown immensely in popularity over the last several years and are primarily used in smartphones, monitors, and any other device that requires both durability and precision.
Advantages of projected capacitive (PCAP) touchscreens
Originally thought of as expensive and unreliable, the technology for projected capacitive touchscreens has consistently improved. Over the years, the cost of manufacturing has come down significantly enough to rival that of many resistive options. The specificity to which the input sensitivity can be tuned has also become advanced enough to reject dust, oil, grease, gels, and other agents, while still effectively gauging user input. This makes them ideal for industries where high cleanability and input precision is required.
Since the input is simply a disruption to the capacitive field, PCAP screens allow for multi-touch functionality, such as zooming, rotating, and more. However, due to the reliance on electrical impulses for input, there are limits to what can be used to activate it. The sensitivity can be tuned to register styluses and gloves, but the item used has to be able to successfully disrupt the capacitive field. This may be less ideal than resistive touchscreens for certain applications, where it may be necessary to use other objects to input information.
Due to PCAP touchscreens not relying on separate panels making contact, damage to the cover glass or acrylic generally won’t affect user input, making them durable enough to handle nearly infinite activations. Because of their construction, PCAP touchscreens also display an extremely high-clarity image. Since the layers are bonded together with optically clear adhesive (as opposed to with an air gap between layers as with resistive touchscreens), the displayed image has a high level of light transmission and is very clear. Coupled with rarely losing calibration, they are durable and remain precise throughout their lifespan.
Ultimately, the decision to use either a resistive or projected capacitive touchscreen comes down to the application. Regardless of what type of user interface system you’re looking for, GMN’s experts can help you find the perfect touchscreen for your next product. Find out more about our display integration capabilities or set up a consultation with our experts.
In today’s world, touchscreens are omnipresent and expected by users on almost any interface system. Widely used in a variety of industries, there are many different types of touchscreen constructions available. Once you have decided to use a touchscreen, there are important design considerations to take into account. How should the touchscreen function when interacted with? Does it need to be durable enough for heavy usage and millions of actuations? Should it be incredibly precise and not require any calibration? Whether your biggest concern is cost, durability, or functionality, there are many different options.
The most commonly used touchscreens broadly fall into two categories: resistive and capacitive. In this blog, we will be focusing solely on the different types of resistive screens and their core advantages.
What are resistive touchscreens?
Resistive screens are made up of two conductive and transparent layers: a flexible top panel (typically made out of polyester or PET) and a rigid bottom panel. An adhesive spacer lies between the two layers. When pressure is applied to the top panel, it makes contact with the panel below. This contact interrupts a continuous current flowing between the panels, where a grid of horizontal and vertical lines allows a controller chip to know what was touched and gauge input accordingly. Since the input is calculated through physical pressure causing the two layers to make contact, resistive touchscreens work well for any gloved or stylus usage.
Types of resistive touchscreens
4-wire resistive touchscreen
The least expensive of all of the touchscreen options, 4-wire touchscreens are typically found in games, toys, and other inexpensive touchscreen applications. Since the accuracy is based on the top panel interacting with the bottom panel, any damage to the top panel will cause the accuracy to degrade. This generally makes them less reliable after heavy usage or many actuations. 4-wire touchscreens also have to be calibrated frequently as they get used to ensure that they register the correct input.
8-wire resistive touchscreen
Very similar to 4-wire in durability and usage, the only difference with an 8-wire screen is additional wiring. This additional wiring keeps the screen more precisely calibrated and allows it to auto-calibrate, meaning that it requires less maintenance to maintain accuracy than its 4-wire counterpart.
5-wire resistive touchscreen
Despite the similar name, 5-wire touchscreens are significantly different from the 4-wire and 8-wire variations. 5-wire screens measure input from the bottom panel only, not in tandem with the top panel. This means that regardless of any damage to the top layer, the usage of the touchscreen and accuracy of input won’t degrade. This makes them more durable and they generally last through many more actuations than other resistive options.
Resistive multi-touch screen (RMTS)
Resistive multi-touch screens (RMTS) are the only type of resistive screens that allow for multiple-touch functionality, such as pinching, zooming, or rotating. Similar to 5-wire screens, the bottom layer is the only layer that measures input, meaning that they’re more durable and well-suited for a rugged environment. EMI mesh can also be applied to the front surface, protecting internal components from outside electrical activity. This, in combination with the durability, makes them favorable for military and industrial applications.
Resistive touchscreens are a great option for a wide variety of applications and industries. To learn which touchscreen option is right for your next product, take a look at our front panel integration and bonding capabilities or request a free consultation with our technical experts.