Friday, January 22, 2010

Wall TV Like a Painting

Slim LED backlight LCD TVs are becoming avialable at reasonable prices. This raises the prospect of mounting them on the wall, like a painting. Kogan are offering a 41 mm thick 26 Inch TV for around AU$600. These have provision for the usual VESA wall mount. The screen is thin around the edges and so would appear to float away from the wall. It might be interesting to mount it amongst some paintings, put an artwork on the screen and see how many people notice it is a TV.

Labels: , , , ,

Wednesday, June 24, 2009

Sony LCD TV Presence Sensor

Sony 40The Sony BRAVIA 40 inch WE5 Series HD LCD TV comes with a "Presence Sensor". This can be switched on so that the unit will turn off the screen to save power if it detected no one is in the room. It switches the picture back on instantly when someone comes in. The feature does save power with my measurements showing a drop from 109 Watt to 60 Watt.

Presumably this feature works using an infra-red sensor, as used in low cost burglar alarms. The sensor appears to have a range of about 3.5 m over 120 degrees. The time can be set to 7 seconds to test the feature. It might be set to five minutes for a screen which is only used occasionally or thirty minutes more typically.

The system works very well and would be useful in education and for digital signage. One problem is that the feature does not seem to be active when the TV is receiving VGA input. Otherwise it could be used in meeting rooms and parts of libraries not in constant use. One feature I would like to see is the screen brighten slowly, rather than come on suddenly at full brightness.

Also it would be useful if the feature had a second stage which would switch the unit to standby after a further period of inactivity. That would save more power (dropping consumption to 25 Watt), at the cost of the unit taking longer to restart.

See also:
  1. Sony 40 Inch LCD TV Initial Impressions

  2. Sony BRAVIA WE Series LCD TV".

ps: Sony TVs are also available via but may not be versions suitable for Australian TV: Sony BRAVIA W-Series 40-Inch LCD HDTV

Labels: , , , , ,

Sony 40 Inch LCD TV Initial Impressions

Sony 40The Sony BRAVIA 40 inch WE5 Series HD LCD TV comes in a box 210 x 1250 x 785 mm weighing 26 kg. It is light enough for one person to lift, but so large it takes to to move it. This is much heavier and larger than a LCD projector. But it is lighter than a comparable sized plasma screen.

The unit is relatively simple to unpack and assemble, with a stand which slots into the bottom of the screen and is held with four bolts.

I connected an VGA cable to a computer and composite input from a digital set top box. The unit also has HDMI 2 input, but I did not have a HDMI cable available. No cables were supplied with the unit, apart from the power cable.

Plugged in using VGA to my laptop, the screen gave a very clear computer display, but disappointingly dim. The display was not bright enough to be used in a room with sunlight coming through the window. The display was unusable in conditions where a 24 inch Dell 2405FPW LCD display worked fine. When sunlight in the room was reduced, the screen brightened enough to be usable.

Plugged into a digital set top box via component video, the unit gave an acceptable resolution image. However, as with the PC display, the image was not bright enough to be comfortably viewed. It turned out that this was a problem with the Power Saving feature. When set to "high" this dims the screen. This makes the unit not bright enough for typical digital signage or presentation applications. Turing this power saving setting to "off" was the only way to obtain an acceptable level of brightness.

Power consumption

When I plugged the unit in it drew 76 Watt. The unit arrived in "shop" mode, with the power savings setting turned off. It took some time to work out how to turn off this mode. Many people would not find, or not be able to set, the power saving setting and Sony should set them on before delivery.

The unit used 120 Watt when displaying moving component video and 123 Watt with PC input. When in standby mode it used 26 Watt. The unit also has a physical power switch which reduced consumption to less than 1 Watt (the limit of measurement of my power meter).

Safety Problem

The instruction manual for the unit includes advice for preventing the TV from toppling over. This says to install a machine screw (not supplied) into a hole on the the TV and tie a "strong cord" (not supplied) to it, with the other end secured to the TV stand with a bolt (not supplied). These instructions will not be relevant in most educational and digital signage applications, where the unit will be securely attached to a wall with a Vesa mount. However, the manual instructions are inadequate and the unit is unsafe for home use, as supplied. The unit should be withdrawn from retail sale until this is corrected.

See also: "Sony BRAVIA WE Series LCD TV".

ps: Sony TVs are also available via but may not be versions suitable for Australian TV: Sony BRAVIA W-Series 40-Inch LCD HDTV

Labels: , , , , ,


Sony 40Sony have loaned me a Sony BRAVIA 40 inch WE5 Series HD LCD TV to try out for a few days. Specifically I wanted to see if this unit save much energy. The application I have in mind is for learning commons, where flat screens are used for digital signage and for presentations. In this applications the screens tend to be left on all day, so energy use is an issue.

One disappointment is that according to the specifications, the unit appears to be florescent backlit, not LED. As a result the backlight has to be all on, or off, the lighting behind black parts of the image can't be turned off.

However, the unit offers a Presence Sensor, which would be useful for public venues. This switches the picture off when no one is in the room. Sony claim this saves 50% of the power. This could be good for presentation screens, which tend to get left on. It may also be very effective for some applications of digital signage: when the person come within viewing range of the screen it will light up, thus attracting their attention.

At present the TV is still in the box, on the floor, some comments about how it goes to follow...

ps: Sony TVs are also available via but may not be versions suitable for Australian TV: Sony BRAVIA W-Series 40-Inch LCD HDTV

Labels: , , , , ,

Monday, May 04, 2009

Display Screens for Medical Imaging

Browsing through the diminishing collection of paper magazine at the University of Canberra library on the weekend I came accross an article on the use of LCD screens for displaying medical images. This goes by the acronym PACS (picture archiving and communication systems). It is used to manage digitised old fashioned X-rays, as well as ultrasound, magnetic resonance and computed tomography. Having been subject to all these procedures recently, I found it of interest.

Because of the risk of missing something on an x-ray, there are specially made and calibrated (and therefore expensive) LCD screens. One interesting way to quickly check a monitor is to display text in subtly varying colours and ask the user to type it in. There is open source medical imaging software available.

Labels: , , , , , ,

Sunday, January 11, 2009

Energy efficient LCD monitors with Led back-lights

Newer LCD monitors (and screens in some laptops) are being made with LED backlights in place of the previous fluorescent ones. These allow finer control of the light and so provide energy savings. The new Dell G-Series models are claimed to use half the power of their predecessors: 18W for the G2210 22-inch and 20W G2410 24-inch. One catch with this is that Dell is not offering smaller size LED models. The larger the screen the more power needed. So if you replace a 17 inch florescent back-light screen which uses 20 Watts (Dell E1709W) with a new LED 22 inch one which uses 18 Watts , you are only going to save 2 Watts (10% not the claimed 50%).

But there are some other power saving features of the monitors which may still make them worthwhile. They only use 0.15W in sleep mode, compared to 2 Watt for previous units. Also a sensor reduces the screen brightness automatically in dim rooms. The screen is also dimmed when displaying a mostly white image. Apart from saving energy, it can be painful for the eyes to be suddenly confronted with a very bright white screen.

The screens are also ENERGY STAR and EPEAT Gold compliant. A claim of being 28 percent lighter than comparable models seems a little odd, as LCD screens are not very heavy anyway. But perhaps this indicates less material is needed to make them, which is an environmental benefit.

Labels: , , ,