标签: touchscreen

The management of sensor inputs has become highly important as embedded wireless devices and mobile platform applications become more sophisticated. Typical of the complexity of this task is the nature of the user interface on mobile phones, where capacitive touch 2D user interfaces are being superseded by a range of 3D sensor applications designed to allow the device to identify gestures and recognize what they mean.   It is also becoming commonplace for advanced smartphones to also collect information on location using GPS signals and determine device orientation and status from information gathered by integrated 3D MEMS position detectors.   Coming soon will be the ability to identify the location of mobile devices in buildings by a variety of wireless sensors. And with the current enthusiasm about the Internet of Things, consumer device makers are thinking about a whole range of wearable electronic devices and home network sensor apps that collect information about their environment and send it back to a smartphone for analysis and interpretation.   The challenge for developers of the embedded subsystems will be how to manage the massive amounts of sensor information coming in and interpreting it as to context, orientation as well as other factors, and making decisions based on that input. But where on the average 2D touch screen smartphone of a few years ago the designer only had to worry about ten or so sensor inputs, the new application environments will require the ability to manage hundreds of such sensor data streams.   Rich Collins, author of “Sensor fusion enables sophisticated next-gen applications," says that to achieve this, developers will have to pay much more attention to more sophisticated sensor fusion methods and algorithms to handle the workload.   In the view of RTI's Supreet Oberoi, author of "Sensor fusion brings situational awareness to health devices," if this fusion can be achieved and it is possible to consolidate and integrate this data in real time, "we have opportunities to develop new suites of smart applications that can change the way we manage our health, drive our cars, track inventory--the possibilities are endless."   But he cautions that it will require several new technologies to make this happen, including fusion techniques for acquiring and organizing information and algorithms for situational awareness that will "make the system as a whole and the device acquiring and using that data aware of the specific environment in which that data is to be used."   Fortunately, a lot of work has been going on to come up with techniques you will need to explore this new application area. This is an exciting field that greatly expands the opportunities and challenges available to designers of embedded systems, and I will be tracking its developments, looking for papers and conference presentations that provide new tools and techniques to speed up and simplify the process. I also look forward to your contributions to this topic, including comments here and as design articles and blogs you may want to contribute on the tools you have found helpful, new ways to use them, and what new techniques for sensor fusion you have found effective.   Personally, I look forward to the capabilities sensor fusion will add to mobile phones and consumer devices (such as MP3 players) that enrich my life, not to mention the medical devices (such as glucose testers) upon which my life as an insulin-dependent diabetic depends. And a device I can attach to my key ring so my lost keys are findable.   In previous blogs, I have complained that the only portable electronic device I can be reasonably sure of finding is my cell phone, because I can call it up from my house phone and listen for the ring to tell me where it is.   Forget that solution for my MP3 player and my glucose meter, because I can’t call them up. I often put my MP3 down and then can’t find it for as much as a week. So I have several MP3 players - and several glucose testers – stashed in strategic places around the house, so an alternative is available until I find the original.   And then there are the many TV remote controls I have lost and am still finding hidden under chair cushions and in various nooks and crannies in my home.   The optimist in me says that the with device location and monitoring capabilities that sensor fusion technologies will bring to ordinary things in my life, I will be able to stop buying duplicates of everything portable, wireless, and untethered.

As you can notice in my bio at the end of this article, I work as a manufacturing engineer. One of my favorite things that happens on a Friday late in the afternoon is to hear my phone ring and see the number of a technician come up: I just know he's going to inform me that a machine has just undergone some kind of catastrophic failure.   OK, maybe it's not my favorite thing to do, but if our jobs were fun all the time, we'd probably be working for free.   Although I've learned (hopefully) to appear outwardly patient and in control, at the back of my mind is the constant nagging fear that I will literally never be able to go home because I can't figure out what's going on. Or maybe I have now run into the one problem that finally can't be solved, and I'll get fired.   The good news is that I've always made it home (so far) and in some cases I've even made it home on time. What follows are a few problems that seemed complicated at the onset, but were quite simple to solve in the end, and the lessons I learned.   Case 1: Recently, I was called out to look at a machine because the vision system was working correctly, but the display was not. The technician who immediately serviced it said he checked the wires and cycled the VGA monitor off and on to no avail. Fortunately, I'd seen this before and, seeing the male side of a VGA cable lying on the floor, soon found its mate. I then stuffed it further into the machine where it would hopefully not get knocked out again.   Lesson: Make sure everything is plugged in!   Case 2: Another machine kept faulting out because a pneumatic cylinder was supposedly not in the correct position. The technicians claimed the sensors were working correctly, but after maintenance changed out a drive motor, things still didn't function correctly.   Our electrical engineer hooked up to the PLC with a computer, and after I manually manipulated the cylinder that we suspected the problem was coming from, all the sensors appeared to check out. Actually, there was one sensor that seemed to have some issue going on, but after adjusting the position, it appeared to work. I initially asked the tech to get more of these sensors but, after seeing it working correctly, decided this wasn't necessary.   After trying to troubleshoot this machine for another hour or so, I saw this sensor again not come on. We then changed it out and found the original sensor with frayed insulation at several points. The machine then performed as it should.   Lesson: Sometimes you should trust your gut, especially when it's easy to follow!   Case 3: Working with the same electrical engineer from the “Catastrophe!” before, we had a small touch panel that needed to be replaced. He loaded the program on, but unfortunately, we kept getting the message “Over Reject Limit.” The touch screen didn't seem to work correctly at all and wouldn't let us reset the counter. Then -- after quite a bit of troubleshooting -- I happened to swipe my finger across the screen in a way that made the screen change. Maybe the display wasn't set up correctly?   This particular touchscreen had an option to calibrate the display. Naturally, we'd ignored it. Obviously, the problem was more complicated than that. Well, it wasn't. After running the calibration routine, the machine was able to reset correctly.   Lesson: If there's an option to calibrate equipment, it's probably there for a reason!   If you're ever in this situation (as undoubtedly most of our readers are from time to time), don't forget to check the simple fixes first. If that doesn't work, move on to the next set. I'll write about attacking those situations in my next blog.   Jeremy Cook is a manufacturing engineer with 10 years' experience and has a BSME from Clemson University.

In a recent product introduction , Cypress Semiconductor mentions a new approach to mobile touch sensor technology, called metal mesh. It said the company is partnering with FujiFilms to bring this technology to a wider range of smartphones as an alternative to traditional indium tin oxide (ITO) and aluminium-doped zinc oxide (AZO) displays. I have been keeping an eye on the display market and I noticed recently a couple of trends recently that seem to me required something other that AZO and ITO based designs. One is the trend towards larger displays in traditional mobiles and tablets and the other was a shift to "up close and personal" wearable electronics. Both will need more flexible display substrates that are less prone to cracking in the case of large screen mobiles and are more flexible and bendable for wearable devices. Talking to Vikas Dhurka, product marketing director for TrueTouch touchscreen solutions at Cypress, I found out that they had spotted the same trends and think that FujiFilm's metal mesh technology is a very promising way to address both issues in a potentially very large market. According to Jennifer Colegrove, Ph.D., president of Touch Display Research Inc., the potential market for flexible and curved displays in which metal mesh would play is estimated to grow from less than 1% market share this year to $27 Billion and 16% market share of global display revenue by 2023 ( figure ).   Figure. Market for up close and personal flexible and curved displays. (Source: Touch Display Research, Flexible and Curved Display Technologies and Market Forecast Report, September 2013) Durkas said metal mesh displays are built using thousands of copper wires, each smaller in diameter than a strand of human hair and offer greater flexibility. In traditional consumer electronics devices, he said, shifting from the traditional indium tin oxide (ITO) based screens to ones based on metal meshes made of copper would not only make them cheaper to produce but make them more noise immune and easier to manufacture. "ITO is an etching process that is expensive, while metal meshes are laid down in a process similar to that of a semiconductor device in a layered fashion," said Dhurka. Based on its assessment of the technology, Cypress Semiconductor has expanded its TrueTouch capacitive touchscreen controller family to include support for metal mesh sensors technology from Fujifilm as an alternative to indium tin oxide (ITO) and aluminium-doped zinc oxide (AZO). Among the reasons for the shift, he said, is that because the metal mesh sensors are copper based they face less resistance in sending signals out to the electronics than existing multi-element based compound materials, making possible brighter and more easily readable displays. But what made Cypress sit up and take notice is that unlike ITO or AZO, metal mesh sensors are bendable, which will be a requirement for many of the personal wearable electronic things that are considering for the next generation of consumer electronics. "ITO is prone to cracking as standard smartphone and tablet screens get larger," said Dhurka, "and in the more curved flexible screen wearable designs that are being considered it is not a viable alternative." But beyond the bendable features, an advantage of metal mesh is that it will allow mobile makers to build lower cost phones with capacitive touch technology. The technology also improves touchscreen sensitivity and delivers robust noise immunity. Because the mesh consists of almost invisible copper wiring with the diameter of a hair, a display built using it is much more transparent than one built with ITO. Unlike ITO, a display fabricated with hair-thin ( 4 micron diameter ) copper wiring can be very dense before transparency is affected, allowing the incorporation of additional electrical redundancy which improves yields and lowers cost. According to Dr. Colegrove, metal mesh-based touch displays will make possible the creation of next generation of aesthetically pleasing wearable devices and things that because they are bendable can be contoured to the curves of human body. "Flexible and curved displays are more ergonomic for the wrist," she said, "and larger-sized flexible displays could fit better and show more information." Cypress is offering the CY3290-TMA500 and CYTK58 TrueTouch Evaluation Kits for developers who want to design their next UI-based products with Fujifilm metal mesh sensors. But Cypress and FujiFilm are not alone in going after this new consumer and mobile display technology. Metal mesh has started shipping in a couple of nextgen touchscreen-based smart phones. And competitors to FujiFilm such as MNTech in Korea and Unipexel are shipping metal mesh to their customers. Also, Atmel has partnered with CIT in the United Kingdom and as of late last year shipped its metal-mesh based XSense line of flexible touch sensors for use in a smartphone and a seven inch display Tablet. Several companies in China are also shipping.  

We all know that flexible PC boards have been here already for quite some time, in fact I can remember using them in avionics back in the 80s. More recently we have seen other aspects of an electronic system becoming more flexible. Apple clearly sees that before long, touch screen displays will be flexible and allow iDevices to be created that can take on different form factors. A few weeks ago, Apple had a patent application publish (notes – this does not mean that the patent has been awarded, only that the application has been published for everyone to see) that talks about the capabilities that such a device may have. The application number is 20130044215.   The abstract states: A wearable accessory device is disclosed. The wearable accessory device includes a flexible display coupled to a bi-stable spring. Coupling the display to the bi-stable spring allows the accessory device to be easily worn in a number of convenient locations. Claim 1 is a very interesting claim in that it talks about several ways in which such a device could be used: A wearable video device arranged to be worn by an end-user, comprising: a flexible substrate having a flat state and a curled state; a flexible display disposed upon a first surface of the flexible substrate, wherein in the curled state the flexible substrate conforms to an appendage of the end-user, the flexible substrate further comprising: an electronic module in communication with the flexible display, the electronic module providing information to the display, at least a part of which is presented in real time for presentation by the flexible display; and a mechanism for detecting an end portion of the flexible display, the detection for adjusting the arrangement of information shown on the flexible display to match the size of the appendage the wearable video device is mounted on.   Now aspects of this patent have appeared in the past and even in patents that have been granted. This is why the Apple application has to combine certain elements together where only one aspect of it has to be fully new and unique. In this case it appears to be the use of a continuous flexible display that can be used in several form factors. The other factor that they talk about quite a lot but do not mention in the first claim is the use of a bi-stable springs. Brian Bailey  

We are all aware that flexible PC boards have been around for a while, in fact I can remember using them in avionics back in the 80s. More recently we have seen other aspects of an electronic system becoming more flexible. Apple clearly sees that before long, touch screen displays will be flexible and allow iDevices to be created that can take on different form factors. A few weeks ago, Apple had a patent application publish (notes – this does not mean that the patent has been awarded, only that the application has been published for everyone to see) that talks about the capabilities that such a device may have. The application number is 20130044215.   The abstract states: A wearable accessory device is disclosed. The wearable accessory device includes a flexible display coupled to a bi-stable spring. Coupling the display to the bi-stable spring allows the accessory device to be easily worn in a number of convenient locations. Claim 1 is a very interesting claim in that it talks about several ways in which such a device could be used: A wearable video device arranged to be worn by an end-user, comprising: a flexible substrate having a flat state and a curled state; a flexible display disposed upon a first surface of the flexible substrate, wherein in the curled state the flexible substrate conforms to an appendage of the end-user, the flexible substrate further comprising: an electronic module in communication with the flexible display, the electronic module providing information to the display, at least a part of which is presented in real time for presentation by the flexible display; and a mechanism for detecting an end portion of the flexible display, the detection for adjusting the arrangement of information shown on the flexible display to match the size of the appendage the wearable video device is mounted on.   Now aspects of this patent have appeared in the past and even in patents that have been granted. This is why the Apple application has to combine certain elements together where only one aspect of it has to be fully new and unique. In this case it appears to be the use of a continuous flexible display that can be used in several form factors. The other factor that they talk about quite a lot but do not mention in the first claim is the use of a bi-stable springs. Brian Bailey