LCD, LED or VFD - Page 1
Forum section: electronics / general

author: codeboy2k
author_rank: Super Contributor
timestamp: June 03, 2012, 04:19:16 am
content: I was curious about peoples preferences for tech equipment on their benches.I am not talking about oscilloscopes here, but all the other glowing equipment that can be operatedwith a front panel and has multi-digit or multi-character displays (i.e. 7-segment, 14-seg, 16-seg, dot matrix).This would include power supplies, frequency counters, function generators, timers, pulse generators, etc. Most of the cheaper, older, or used stuff oftenhave numerous displays on them. Consider your home brew items too, not just commercial products. If you're building it yourself, what would you choose?Do you care? Do you have a preference? is one easier to read than another? does a particular color sooth the beast inside you ?Everyone can vote twice in the poll. I've done that you can give another preference, for example 1 color in LCD and 1 color in LED.I don't know how much it will skew the results by allowing 2 votes per person, but it's just informal fun anyways.Please answer the poll and let me know.Thanks!

author: AntiProtonBoy
author_rank: Frequent Contributor
timestamp: June 03, 2012, 04:28:49 am
content: White LED and VFD.VFD has a special place in my heart, even though they tend go iffy due to cathode poisoning-like issues.

author: T4P
author_rank: Super Contributor
timestamp: June 03, 2012, 06:34:40 am
content: I would use VFD but heck,White LED is the best or Blue if you like

author: johnnyfp
author_rank: Frequent Contributor
timestamp: June 03, 2012, 06:46:01 am
content: What about OLED!

author: T4P
author_rank: Super Contributor
timestamp: June 03, 2012, 06:58:06 am
content: Quote from: johnnyfp on June 03, 2012, 06:46:01 amBeautiful but ... pricey

author: codeboy2k
author_rank: Super Contributor
timestamp: June 03, 2012, 08:48:26 am
content: Quote from: johnnyfp on June 03, 2012, 06:46:01 amI considered adding OLED to the poll, but frankly there's not enough LAB equipment available with OLED displays.LED, LCD and VFD have been entrenched in the industry for years, and I expect most people have developed a preferencefor one over the others. But OLED didn't seem to have enough history yet.The poll is not about what you wish you could have, but what you actually prefer based on experience.And they are pricey, as DaveXRQ says. However, I think they will be about the same price as VFDs but VFD's still win on lifetime.OLED's aparently lose half their brightness in 5 or six years of continuous operation @ 8 hours per day. Some lab equipment is left onfor days at a time, and the OLED display just won't last. I think the organic components decompose or something. Other than that, I thinkthey are much better than all the other display technologies. Once they get the lifetime up and the price down, they will be great.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 03, 2012, 08:59:24 am
content: What about E-Ink...? A DMM with a fast E-ink display would be awesome!IMO things like update rate, size and user interface are far more important than colour & type. As long as it's readable it's fine.I dislike old low-contrast graphic LCDs with narrow view angles, and VFDs with uneven segments due to burn-in, but anything else is fine.

author: G7PSK
author_rank: Super Contributor
timestamp: June 03, 2012, 09:24:56 am
content: I like needle pointers and moving scale equipment as well there is no tick box for this.

author: Bored@Work
author_rank: Super Contributor
timestamp: June 03, 2012, 10:35:25 am
content: Quote from: mikeselectricstuff on June 03, 2012, 08:59:24 amDo you know of any instrument with an e-ink display?QuoteI would be concerned about failure mode. If the meter fails, e.g. the battery got flat, or you maybe just forgot to turn it on, there would still be something displayed.But if you want to go DIY, Eink offers samples of naked fixed-segement displayshttp://www.nexternal.com/eink/standard-segmented-display-samples-c4.aspxfor $50 for a pack of five. 10 bar graph, 6 digits x 14 segments, and 8 digits x 7 segments (no, no decimal point) are available. I have no idea how to drive them and haven't ordered any. They also have a matrix display eval kit. In the past it was a few thousand Dollars, these days you have to beg them, i.e. "qualify", to get one.

author: T4P
author_rank: Super Contributor
timestamp: June 03, 2012, 10:39:46 am
content: Quote from: Bored@Work on June 03, 2012, 10:35:25 amMost of the amazon readers use E-Ink's

author: chrome
author_rank: Regular Contributor
timestamp: June 03, 2012, 11:16:19 am
content: Quote from: DaveXRQ on June 03, 2012, 10:39:46 amBelieve it or not, an amazon reader is not lab equipment.

author: T4P
author_rank: Super Contributor
timestamp: June 03, 2012, 11:21:08 am
content: Quote from: chrome on June 03, 2012, 11:16:19 amOops. Not instrument.OK, no instrument uses E-INK .

author: Hypernova
author_rank: Unknown
timestamp: June 03, 2012, 11:50:30 am
content: VFD - The type of "bling" it adds to an instrument simply has no equals.

author: ejeffrey
author_rank: Super Contributor
timestamp: June 03, 2012, 12:28:17 pm
content: I like VFDs. I spend a lot of time in dark optics labs, and a display that you can read in the dark is a big plus. I prefer the digits to be illuminated rather than backlit, and the viewing angle of most transflective segmented or character cell LCDs is pretty terrible, especially when backlit. Active matrix color LCDs are nice, but they are kind of overkill for most instruments whose primary output is not graphical. Obviously for scopes and spectrum analyzers LCDs are the only choice.

author: siliconmix
author_rank: Frequent Contributor
timestamp: June 03, 2012, 12:36:53 pm
content: how about a speaking one for the hard of seeing.

author: SeanB
author_rank: Super Contributor
timestamp: June 03, 2012, 12:42:43 pm
content: You will be asking for a Braille display next..............

author: free_electron
author_rank: Super Contributor
timestamp: June 03, 2012, 01:45:08 pm
content: The key is having high contrast and be not overly bright.Instruments with white text on blue backlit lcds are horrible to read same for black text on yellow or red backlit lcd...Simple displays such as old fashioned led behind a filter and vfd are preferred. Off is black ... And not ' low level light as with lcd...There are lcd displays ( optrex) with white backlight that are monochromatic. ( black/white ) . Those are excellent.I prefer my lab in half dark with a woking light shining on my test subject.Paradise by the blinkenlights...

author: codeboy2k
author_rank: Super Contributor
timestamp: June 04, 2012, 06:14:53 pm
content: Quote from: free_electron on June 03, 2012, 01:45:08 pmI agree with that completely. I absolutely hate white on blue LCD (those 2 line x 20 char displays). Black or white on a red background is equally horrible.But black on yellow or yellowish-green LCD is ok to read. That's a common combination.You once said you were colorblind. Do you find that affects your ability to read some instrument displays? perhaps some manufacturers are not considering this. I imaging some o-scope traces can't be read easilyQuoteI love the white backlit monochrome LCD's that you mentioned. They are just so crisp and easy to read.

author: codeboy2k
author_rank: Super Contributor
timestamp: June 04, 2012, 06:23:33 pm
content: Quote from: siliconmix on June 03, 2012, 12:36:53 pmI always wanted the auto mode of the DMM to beep and speak everytime it got a new reading.Turning my head to look up at the meter, I still have occasionally slipped a probe and fried something.And I have yet to master the one-handed probing like I saw Dave do in one video. Dave was holdinghis probes like chopsticks and the meter in the other hand.clearly he thought the DUT was Dim Sum.

author: free_electron
author_rank: Super Contributor
timestamp: June 05, 2012, 12:06:51 am
content: Quote from: codeboy2k on June 04, 2012, 06:14:53 pmyes it does. on a scope the yellow and green trace look identical since they have same luminosity.that is something i found fantastic on the Rohde & Schwarz scopes. They let you set trace color and, since the have full RGB led's behind the buttons ont he control panel , the control panel actually changes accordingly !That is a brilliant design. Like if you set the trigger to channel 3 ( blue ) the led behind the trigger button changes to blue as well. So you see 1 one step what you are linked to. ( as opposed to needing 4 leds , to show what you are tied to. simply change the ring around the level knob to the selected trigger trace color )i wish more manufacturers woudl do that. rgb led's are peanuts on the cost of the scope

author: codeboy2k
author_rank: Super Contributor
timestamp: June 05, 2012, 05:58:11 am
content: That is a brilliant design. I've never used R&S scopes , so I didn't know.Manufacturers need to know how their choices are affecting your abilities to use the scope, and ultimately how it affects a purchasing decision.

author: Zero999
author_rank: Super Contributor
timestamp: June 06, 2012, 01:04:30 am
content: I suppose you could use an LCD with an RGB backlight and a reversible polarising filter to give a choice of colours and whether it's positive/negative or you could just go the whole hog and use a full colour graphic screen, giving endless possibilities, including VFD and nixie emulation.I'm happy with most colours (red, orange, yellow, green, cyan, white etc.) with the exception of bright blue, indigo, violet or pink which make my eyes sore. Unfortunately bright blue and indigo seem to be common these days but at least with an LCD it's often possible to change the backlight to a more sensible colour.