Touch Me!

click here to read this article in ProSystems Africa News magazine July/August 2016.

These days the words ‘screen’ and ‘touch’ go together like bacon and eggs. It’s nothing new to touch a display screen and expect a relevant response. Consumer grade mobile phones, tablets and most notebooks are all touch-enabled. Interacting with a display has become part of our daily lives.

Many moons ago the idea of touching a display to initiate a command was only known from Hollywood sci-fi. Touch Screen technologies have been experimented with from as early as the late 1960s. However it was only around the turn of the century that we saw touch enabled point of sale systems and interactive information kiosks become more customary in retail spaces. High-end meeting and conference venues utilized state of the art touch overlays over LCD and plasma screens, and back then homes-of-the-future had touch panels with processors controlling their environments. Interactive projection also grew in prevalence, but has never entertained the same levels of attention as touch LCD screens. In the case of interactive projection, ultra-short throw projectors are paired with infra-red or radar devices which cast a separate grid over a projected image. A stylus pen or finger is then used to interact with the grid on a solid surface such as a white board with a low reflective surface.

LCD touch technologies have seen many iterations over the years. Each variation of touch screen architecture focused on the key features - accurate touch and near instant response time - but with an objective of improving a previous result. The biggest challenge in any touch technology is for interaction to be acknowledged by the system and then another challenge is to determine the precise location of the touch on the screen.

The aesthetics of modern day touch overlays such as capacitive and resistive technologies used in smart phones, tablets and kiosks mask very well any visible hint of external technologies. Capacitive Touch screens consist of a conductive coating over a transparent insulator, such as glass. The human body, being an electrical conductor itself, then disturbs the screen’s electrostatic field when touching it. Many variations of capacitive technologies are available, but essentially these function in a similar way. A grid array of sensors is continuously scanned to determine the location of the touch. Resistive Touch screens consist of two layers, each with a fine grid of conductive material placed over each other with a micro cavity in between. The top layer is typically softer, and, when pressed down, makes contact with the bottom layer. A short-circuit registers a resistance in the voltage which will indicate a touch. The X and Y coordinates of the grid determines the location. Not all touch screens are as smooth looking. Alternative technologies have equipment integrated into the bezel of the screen, with protective glass covering the display surface. Because of the integration in the bezel, the latter sits proud from the display surface and could be perceived as a bulky finish.

Surface Acoustic Wave (SAW) and Dispersive Signal Touch (DST) are vastly different technologies but both utilize wave interference by finger touch. SAW systems emit ultrasonic waves over a display from two sides and then measure the same waves from the remaining two sides. An object interfering with these waves will absorb a percentage of the energy and the relevant touch controller then measures the change in amplitude in order to determine the touch location.  DST in turn, measures the bending waves created by a finger touching a display surface from all around the surface area. This is similar to the ripple effect of a water surface when disturbed. Neither of these technologies is very popular because of substantial interference of surface particles such as dust or humidity.

Infra-red (IR) touch systems have IR emitters and sensors around the bezel of the display to form a grid in front of the touch surface. When touched, one or more light paths are broken and based on XY coordinates, a touch, and its location, is registered. Optical Touch systems have LED lights integrated into the bezel, which creates an invisible light layer over the display area. Two cameras from the top corners are monitoring disturbance in the light plane and thus determine touch and location. These technologies do not perform well in very bright environments.

Shadow Sense Touch (SST) is the newest kid on the block. LED lights are integrated into the sides and bottom of a display bezel, with optical sensors in the top corners and top bezel. These sensors measure a shadow created by the interference of a light path. Because of SST architecture being positioned in the bezel, the product, like other optical touch technologies, is also available as a video wall over-frame kit. Individual bezel pieces are mounted around the perimeter displays in a video wall up to 6m in width. These bezels then function collectively to create a touch capable video wall.

SST not only determines a touch and its location, but also identifies the shape of the touch-object used. Software then allows the user to configure a set of parameters in order to accept certain shapes, and ignore others. This feature revolutionized the world of annotations because fingers and pens can be recognized, whilst suit cuffs and hand palms can be dismissed. This in turn reduces headaches, frustration and violence in the workplace.

Laser Projectors in the spotlight

Article published in ProSystems Africa News magazine Sep/Oct 2015 edition.
Access article on ProSystems Africa News Site

There is a saucy new item on the projector menu called lamp-less laser projection. Not only is it dripping with solid state lighting goodness but it is also served with a large side order of benefits.

Laser projection, albeit topical, is not just the flavour of the day. With light-source life expectancy of up to 20 000 hours and almost no maintenance, the low cost of ownership is the main appeal. This makes for nearly 10 years of operation on an 8 hour daily, 5-day week basis. The advantages pile up, with higher brightness levels, higher contrast ratios and better colour and brightness uniformity. Also, low thermal emissions result in low noise due to the reduced cooling requirements. Along with a near-instant on/off feature, these projectors really tickle the taste buds and also if that is not enough, lamp-less technology results in an absence of mercury, which makes for a fully recyclable, environmentally friendly product.

Traditionally, projector selection has been based on resolution and brightness, irrespective of the light source. The imaging-technology did play a role but unless it was specified in a system design, it didn’t influence the decision process. Conventional projectors use UHP (Ultra High Performance) and HID (High-Intensity Discharge) lamps. These high-cost lamps operate at extremely high temperatures and offer on average only 2000 to 4000 lamp hours depending on the projection conditions. Such limitations just accentuate the giant leap forward achieved by laser technology. With projector imaging engines being light-source agnostic, laser is an added advantage to current DLP (Digital Light Processing), 3-LCD (Liquid Crystal Display) and LCoS (Liquid Crystal on Silicon) technologies. Laser – along with LED and OLED – is classified as Solid State Lighting (SSL) and utilises a collection of semi-conductors to convert electrical energy into artificial light as opposed to traditional bulbs with energised filaments and gasses (fluorescent and incandescent lamps). The benefits of SSL technology include life longevity and high-quality light intensity sustained over time. It’s also durable, compact and energy efficient. Laser light systems use low intensity beam-expanded laser and can be divided into three sub-technologies namely, RGB laser, laser phosphor and hybrid laser. RGB laser systems have three primary colour laser sources: Red, Green and Blue laser light in distinctive frequencies is delivered directly onto a DMD (Digital Micro-mirror Device) or LCD imaging chip. RGB laser systems produce a very bright image with extra wide colour gamut and brightness uniformity. Unfortunately, they are bulky and expensive, but are ideal for the digital cinema market. 

Laser phosphor systems optimise one blue laser beam onto a coated phosphor surface which excites a variety of primary colours that are processed to create a full colour spectrum image through a 3-LCD or colour-wheel DLP engine. Great colours, with a fairly compact design and high brightness are all positives. Hybrid laser projectors use a combination of laser and LED light to enhance certain primary colours. Contrary to this enhanced colour technology, it results in a narrower colour gamut and struggles to reproduce some colours in the spectrum accurately. Lower brightness is another limitation. Laser projection is a game changer with an extensive list of benefits which cannot be ignored. It brings a new dimension to the projector market and will remain in the limelight for quite some time.

Review: IFSEC Security Expo 2012

Review published in Promag AV magazine Oct 2012 edition.

Access review on Electrosonic SA Promag site

ABRIE DU PLOOY CHECKS OUT THE IFSEC SECURITY SHOW

As soon as I learnt that Electrosonic SA would be exhibiting at the IFSEC security expo I made no secret about my lack of enthusiasm. The only thing I looked forward to was the skimpily clad models who roam the expo floor marketing products.

I openly admit that I was wrong. The expo was extremely well organised, and the crowd that attended was industry-focused. One tends to forget the size of the security industry in Southern Africa and the enormous number of exhibitors and audience members at the expo was a timely reminder. The show featured 204 local and international exhibitors offering a wide array of security products and services: everything from access control to sniffer dog training. Exhibitors from far and wide demonstrated their products and solutions and more than 6000 visitors arrived to see what was available.

Electrosonic SA's contribution to IFSEC was focused on control room environments and large display requirements. We displayed and demonstrated 3 different high end products. For the front end or display side of our video wall we used the NEC X463UN 46" video wall monitors. These monitors are capable of displaying Full HD (1920x1080) images and offer a full-array, back-lit LED light source to display a crisp, high-contrast picture.

For the back-bone of the video wall solution we demonstrated our Galaxy Video Wall Processor. The processor takes care of all source and content management and can route any source in any format to any one or more of the displays. The processor is also capable of creating multiple new windows of any size, and offers unlimited choice in the arrangement of the total display area of the video wall.

The third product that we demonstrated was the Crestron control system, which consists of a Crestron MC3 processor and a Crestron TPMC-9 touch panel. The Crestron system controlled the Video-Wall and, although it's not required in the solution, it offers a dashboard to the user whereby different window and display pre-sets can be programmed and stored for ease of use.

In general the show was very successful and Electrosonic SA gained great exposure for its quality products; leads were collected and will be validated. Electrosonic SA does not deal with end-users and does not offer any installation services, however we do pass validated leads on to relevant companies in our dealer base.