On 4 Dec 2006 10:27:10 -0800, "Viktor" <vkesler@gmail.com> wrote:> > >On Dec 3, 7:46 pm, Jim Granville <no.s...@designtools.maps.co.nz> >wrote: > >> >> How large a display are you after, on what power budget ? >> >> -jg > >Thanks for the answers everybody. >I must admit, I've never actually seen a real live OLED so all my >information is hazy at best. I imagined it to be something like an LCD >with its own light source. So, I thought that in bright light it would >have a reflective component like LCDs (I've worked with some big LCDs >for petrol station pump displays and they are very good at high ambient >light.) > >The largest 7-segment LED display I found (LITEON) had a 76mm digit >height and was stated at 30mcd/20mA.4" seven-seg displays are pretty common - I think I've also seen 6 & 8">With four digits, and about 20 segments, that would be about 5W. I can >just about manage that, but it wouldn't be at its brightest and it >would probably be poor in daylight.If you need best readability for minimum power, you may want to look at using slim lines of discrete LEDs ( e.g. PLCC-2/4 types) as the segments , so the light is more concentrated & contrast is maximised.
Large 7-segment OLED
Started by ●December 2, 2006
Reply by ●December 4, 20062006-12-04
Reply by ●December 4, 20062006-12-04
On 4 Dec 2006 10:27:10 -0800, the renowned "Viktor" <vkesler@gmail.com> wrote:> > >On Dec 3, 7:46 pm, Jim Granville <no.s...@designtools.maps.co.nz> >wrote: > >> >> How large a display are you after, on what power budget ? >> >> -jg > >Thanks for the answers everybody. >I must admit, I've never actually seen a real live OLED so all my >information is hazy at best. I imagined it to be something like an LCD >with its own light source. So, I thought that in bright light it would >have a reflective component like LCDs (I've worked with some big LCDs >for petrol station pump displays and they are very good at high ambient >light.) > >The largest 7-segment LED display I found (LITEON) had a 76mm digit >height and was stated at 30mcd/20mA. >With four digits, and about 20 segments, that would be about 5W. I can >just about manage that, but it wouldn't be at its brightest and it >would probably be poor in daylight. > >So, is it just wishful thinking or do OLEDs have a reflecive function >like LCDs? > >ViktorNo, they don't. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Reply by ●December 28, 20062006-12-28
"Mike Harrison" <mike@whitewing.co.uk> wrote in message news:u2n7n215v9l98td6p4c0oaaei3a9utu9d7@4ax.com...> On 3 Dec 2006 07:58:44 -0800, "Viktor" <vkesler@gmail.com> wrote: > >> >> >>On Dec 3, 2:00 pm, Mike Harrison <m...@whitewing.co.uk> wrote: >>> On 2 Dec 2006 10:07:55 -0800, "Viktor" <vkes...@gmail.com> wrote: >>> >>> >Is there such a thing? >>> >All I can find on the net are smallish alphanumeric and graphical >>> >displays. >>> >>> >Thanks, >>> >>> Viktor >>>>Why OLED instead of conventional LED? >> >>Power consumption. > > Are OLEDs actually any more efficient than standard LEDs for the same > light output? I suspect > probably not. > OLEDs typically compete with LCDs, which throw away at least 50% of th > backlight light in the > polariser, and then about 60% mode in the RGB filters. Not hard to compete > with that with a > light-emitting product. > >>>From what I've seen in the alphanumeric OLED datasheets, you get decent >>visibility without backlighting. I was hoping to find single or several >>digit displays to make a large clock module with only a few W >>consumption. > > A few W will run a bunch of (carefully chosen) normal LEDs pretty darn > bright. > And it will last longer - OLEDs still have some lifetime issues ISTR.For a nice looking clock display see http://www.sparkfun.com/commerce/present.php?p=GPSClock-1 If you need large segments , this way maybe cheaper and brighter than buying 8" seven segment displays(also powered from 12V) Alex
