Corning® Gorilla® Glass Characteristics
Corning® Gorilla® Glass provides exceptional performance and protection, with distinct advantages over other materials.
Damage resistance: Gorilla Glass is chemically strengthened through an ion-exchange process that creates a deep compression layer on the surface of the glass substrate. This layer acts as “armor” to reduce the introduction of flaws by end users.
Thinner form factor: Depending on application and manufacturer specifications, Gorilla Glass can be produced in thicknesses ranging from 0.5 mm to 2 mm. Even at 0.5 mm, Gorilla Glass retains a performance advantage over other cover materials.
Unparalleled surface quality: Corning’s proprietary fusion process gives Gorilla Glass the same superior surface as all of our high-technology display substrates. This extraordinarily precise, highly automated process produces glass with exceptionally clean, smooth, flat surfaces and outstanding optical clarity.
Compliance with environmental standards: Gorilla Glass is compliant with the Restriction of Hazardous Substances Directive (RoHS).
Compatibility with touch screens: Gorilla Glass is an ideal cover sheet for touch screens. It’s tough enough to handle the surface pressures intrinsic to these devices, and exceptionally thin to enable more sensitive and accurate responses.
Easy-to-clean, wear-resistant coating: Customers can request Gorilla Glass with a special coating, making it easier to clean than other cover glasses – a perfect feature for touch devices.
LCD Features and Attributes
To evaluate the specifications of LCD monitors, here are a few more things you need to know.
Native Resolution
Unlike CRT monitors, LCD monitors display information well at only the resolution they are designed for, which is known as the native resolution. Digital displays address each individual pixel using a fixed matrix of horizontal and vertical dots. If you change the resolution settings, the LCD scales the image and the quality suffers. Native resolutions are typically:
- 17 inch = 1024×768
- 19 inch = 1280×1024
- 20 inch = 1600×1200
Viewing Angle
When you look at an LCD monitor from an angle, the image can look dimmer or even disappear. Colors can also be misrepresented. To compensate for this problem, LCD monitor makers have designed wider viewing angles. (Do not confuse this with a widescreen display, which means the display is physically wider.) Manufacturers give a measure of viewing angle in degrees (a greater number of degrees is better). In general, look for between 120 and 170 degrees. Because manufacturers measure viewing angles differently, the best way to evaluate it is to test the display yourself. Check the angle from the top and bottom as well as the sides, bearing in mind how you will typically use the display.
Brightness or Luminance
This is a measurement of the amount of light the LCD monitor produces. It is given in nits or one candelas per square meter (cd/m2). One nit is equal to on cd/m2. Typical brightness ratings range from 250 to 350 cd/m2 for monitors that perform general-purpose tasks. For displaying movies, a brighter luminance rating such as 500 cd/m2 is desirable.
Contrast Ratio
The contrast ratio rates the degree of difference of an LCD monitor’s ability to produce bright whites and the dark blacks. The figure is usually expressed as a ratio, for example, 500:1. Typically, contrast ratios range from 450:1 to 600:1, and they can be rated as high as 1000:1. Ratios more than 600:1, however, provide little improvement over lower ratios.
Response Rate
The response rate indicates how fast the monitor’s pixels can change colors. Faster is better because it reduces the ghosting effect when an image moves, leaving a faint trial in such applications as videos or games.
Adjustability
Unlike CRT monitors, LCD monitors have much more flexibility for positioning the screen the way you want it. LCD monitors can swivel, tilt up and down, and even rotate from landscape (with the horizontal plane longer than the vertical plane) to portrait mode (with the vertical plane longer than the horizontal plane). In addition, because they are lightweight and thin, most LCD monitors have built-in brackets for wall or arm mounting.
Besides the basic features, some LCD monitors have other conveniences such as integrated speakers, built-inUniversal Serial Bus (USB) ports and anti-theft locks.
Source: HowStuffWorks.
Case study: factors that affect tags’ sensitivity to RFID reader
Scenario: assume you have about 800 cages on the Techniplast racks (each rack contains 140 cages on both sides), so there are around 6 of these racks. Assuming that these racks stands side-by-side in a straight line, and you walk pass them one by one with RH767-II reader trying to read all the tags on those cages.
RH767II
Factors that can affect the tag sensitivity to the reader:
1) Tag decoding speed goes along with your walking speed.
First, your walking speed (2 minutes vs. 5 minutes) can be a big factor in whether the reader can pick up all the tags as you are walking pass them, especially when you have a large population of tags within the read-zone of the reader. When you are passing through the tags with the reader, the reader sends out its signal to all the tags within its range. When a tag receives the signal from the reader, it powers up its energy; when the voltage thread-hole is reached, the tag reflects the reader’s signal back to the reader, along with its modulated data. Once the reader receives the data from the tag, it processes the data to however you program it to do (in your case, it displays the tag data onto the screen of your RH767 unit).
The catch is that the reader can only process one tag at a time. So, when multiple tags receive the reader’s signals at the same time, they’ll attempt to send the signals back to the reader. All of these signals from these tags can reach the reader at the same time. However, only one of them can be processed at a time. Then, the reader will move on and process the next tag signal on the next clock cycle (CPU cycle), and so on. So, if you pass the rack before all the tag signals are processed, you will “lose” those signals, and as a result, you don’t see some of the tags from the rack show up on the reader.
For example, if you walk pass a table with 8 tags on them (see the screenshot below), you’ll notice that the reader does not read and displays all 8 tags onto the screen at once (the reader does this really fast so that it’s not very obvious to the human naked eyes). But, you’ll still notice that the first 6 tags show up almost immediately, but the last 2 tags would take may be 4 or 5 seconds later to show up on the reader (even though all 8 are within the effective range of the reader). If you walk away before the reader processes the last 2 tags (within that 4-5 seconds interval), those 2 tags will be “lost” by the reader.
2) The Metal Rack can possibly detuned the tags near it.
Second, the metal rack is also another factor that can affect the tag sensitivity to the reader. When the reader emits electromagnetic energy and the tag picks it up, it’ll attempt to gather the energy from the reader antenna, and when enough of this energy is accumulated (the voltage thread-hole is reached), the tag reflects back the modulated signal to the reader. This is where the metal rack comes into play. If the tag is near metal when it’s sending out the energy back to the reader, some of these energy will hit the metal part and can be reflected back to the tag. With enough of these “unwanted” signals, the tag’s antenna can be “detuned”. Since the antenna is tuned to receive waves of a particular frequency, being detuned can make it harder for the tag to be able to receive the energy signal from the reader next time it comes.
3) The tag type can affect its sensitivity to the reader.
As a rule of thumb, smaller tags are less sensitive and thus have lower read range.
However, note that more sensitive tags don’t always mean more desirable. It depends on the environment in which the tags are being used and how you factor in the other elements in the environment as well.
4) The tag orientation and its proximity to the reader can also affect the sensitivity of the tag to the reader.
The RH767 has circular antenna, so ideally, the tag that is directly in front of the device would be most sensitive to the reader. The tags that are at the sides, or above and below would be less sensitive to the reader.
See the figure below (top-down view, with Tag-A is in the middle, Tag-B is to the left and Tag-C is to the right of Tag-A).
If you put the RH-767 right in front of Tag-A, it reads the tag no problem. However, the effective reading range toward Tag-B and Tag-C has been reduced significantly. The same thing also applies when Tag-B is directly above Tag-A and Tag-C is directly below Tag-A.
5) Lastly, the population of the tags around the reader can also problematic when it comes to decoding the tags.
If you have a very large population around the tags (a couple hundreds of them within the reading range of the reader), it’s also difficult for the reader to be able to pick up all the tags. If you happen to come across a scenario where your reader needs to be able to pick up several hundred of tags within its read-zone, you would have to implement the Q-Algorithm in your program to effectively decode all the tags. Theoretically, this algorithm prevents tags that have already been read to be read over and over again to allow tags that have not been read to be read. You can study the detail of the algorithm here:
http://www.waset.org/journals/waset/v78/v78-154.pdf
Disclaimer: This awesome case study was done by one of my coworkers. I put it here for future reference. The opinions are personal, not representative of our company.
Unitech PA690 Review
Unitech announced PA690 in Jul, 2011 to replace its very popular PA600 series. With 3.8” large screen display, slim and ergonomic design, and potent and versatile platform, PA690 is even better to fit in today’s aggressive business environment.
PA690 with QWERTY keypad PA690 with numeric keypad
System
CPU: PA690 is based on Marvell 806MHz PXA320 processor. Looking through the ruggedized enterprise handheld and PDA market, this is still the fastest and most popular processor.
OS: PA690’s platform is Microsoft Windows Embedded Handheld (WEH) 6.5, with the opinion of classic or professional versions depending on whether cellular connectivity is needed. Although there are several OS platforms available in the mobile market, such as Windows 7, iOS, Android, etc., most of them are mainly targeted for consumer mobile devices only. As far as enterprise handheld device market is concerned, WEH 6.5 (formally windows mobile 6.5) is still the best of the kind, and Android is catching up.
Memory
With 256MB of Mobile DDR SDRAM and 512MB of NaND Flash, the PA690’s internal memory is ample enough for applications and storage, if not extraordinary. 256/512 is pretty common in market. Some of the devices in market can reach 1G memory.
Featuring a microSD expansion slot with SDHC support, the PA690 is able to reach an additional 32GB of storage capacity for data-intensive applications. With SDHC support, it stands by for additional applications based on SDHC.
Display and keypad
PA690 has a large 3.8” screen with a sharp full WVGA 480×800 pixel resolution. This is a highlight for PA690, making it stand out among competitors. The common practices in market are with screen diagonal size 3.5” or less, and with VGA or QVGA resolution. Some customers may concern that applications developed on VGA or QVGA would not run well on WVGA PA690. To tell the truth, this is not a concern at all. If the application is developed on VGA or QVGA, it will run on the PA690 just fine assuming it supports WM 6.5. Only the view area may be little different. It may have extra empty space at the bottom of the screen as WVGA is wider than VGA. There is nothing on the WVGA screen itself will keep the application from running on the PA690.
PA690 display is sunlight readable, which makes PA60 versatile to applications both inside the four walls and outside straight under the sunlight.
PA690 provide two options for keypad: 26-key numeric keypad, and 44-key QWERTY keypad. Numeric keypad provides bigger keys and it’s the best choice for people that have always used regular keypads and don’t have extravagant needs for texting. QWERTY keypad offers the familiar feeling of blackberry-style and is the best choice if a lot texting is needed from your PDA. Navigation keys, scan key, phone pickup and hang up keys, other regular function keys are available on both keypad options.
Data capture
PA690 offers both 1D & 2D scan engines to efficiently scan all the popular barcodes. 1D barcodes include: UPC-A/E, EAN-8/13, Codabar, Code 39, Code 39 full ASCI, Code 93, Code 32, Interleaved & Std. 2 of 5, EAN 128, Code 11, Delta, MSI/Plessey, Code 128, and Toshiba. 2D barcodes include: Aztec, Codablock F, Code 49, Datamatrix, EAN-UCC, composite, Maxicode, Micro PDF417, PDF 417, QR code, Tcif lonked C39.
It also comes with opinion of RFID high frequency (HF) to read RFID tags that comply with ISO15693, ISO14443A, and ISO14443B standards. For HF part numbers, there are dual Micro-SD module interface: One is in terminal, and the other is in HF module. In this way, customer can use both for storage and for security.
Network and communication
PA690 communicates through cisco CCX4 compliant 802.11a/b/g, Bluetooth 2.1 + EDR, or cellular 3.5G. For WWAN, PA690 uses Summit WiFi module, which provide strong radio signal and excellent roaming capability. For positioning, PA690 uses u-blox® 6 High Performance GPS chipset with AssistNow® Online and AssistNow® Offline A-GPS services, OMA SUPL compliant, and supports new European satellite system GALILEO.
Other highlights
IP Rating: IP65, which is good enough for most of applications.
Drop Test: 1.5 meter.
Accessories: Pistol grip is available and it is field upgradable.
For the full specifications, please see the chart below.
Disclaimer: the opinions in this article are personal, not representative of the company, Unitech.
Summit WiFi module vs. Marvell WiFi module
These comparison results are based on our testing.
- Price wise, Marvell is less expensive.
- Comparing Summit and Marvel cards side by side on our PDAs, Summit card showed stronger radio signal than Marvel card. As you move further and further away from the access point, the Summit card retained the connection better than the Marvel card.
- Summit comes with a nice user-friendly GUI (Summit Client Utility) that allows the end-users to configure the radio. Marvel, on the other hand, does not provide you a GUI to allow you to configure the radio, so if you use Marvel card, you would need to use the generic window tool to configure the radio (this tool is not as powerful as the Summit tool). On top of that, you can import/export your WiFi configurations easily with the Summit GUI. This way, if you lose your WiFi settings, you can easily reload it with the configuration file. You don’t need to re-configure the radio again.
- The SUMMIT roams better from access point to access point.
- SUMMIT supports more encryption types and is Cisco CCXv4 compliant.
