Need hints to find info on 35 year old Sharp LCD display - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 16, 2021, 03:02:48 am
content: I have this great monochrome LCD panel in my box of shiny and not so shiny things. Can't find too much information on this part number, which appears to be a Sharp LM64015W. This seems to be a microwave oven or CNC lathe part number these days?The chips are SED1600F, 80 bit shift registers, which would work out to being a 640 x 480 passive screen.Date codes suggest mid-80s construction, I mean look at the thing.There's a 12 pin interface, which I guess is where you shift in data 4 bits at a time and power the thing.Anyone have a clue of where to look for a datasheet?I'm asking in vintage computing because this might have been a luxurious 286 laptop screen?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 16, 2021, 10:38:21 pm
content: Sharp Global responded to my info request, same day, wow.Of course they said " Due to the age of the unit I could not locate any information on this product"...

author: Halcyon
author_rank: Unknown
timestamp: February 17, 2021, 06:37:49 pm
content: A family member of mine used to work at Sharp. I remember visiting the lab in Australia several times in the 1990's and a lot of those schematics and technical documents were printed out in volumes and volumes of custom-made red "Sharp" binders.I'd say over the years, especially since they cut a lot of their product lines and moved from their huge Huntingwood Australian head office, most of that was binned. Good luck finding original soft copies. Even for things like software and drivers, Sharp were pretty bad at consolidating these kinds of files in one, easy to find place, even internally.

author: rsjsouza
author_rank: Super Contributor
timestamp: February 17, 2021, 10:06:20 pm
content: I couldn't find any info, but the model number is most probably LM64O15 - not "zero"There should be a few scanned Sharp opto databooks - I found one from 1988-89 but it had no LCD displays. Another from 1994 had a few models, but it would probably be too new for the type of display you are showing. If you want to take a look, check:https://archive.org/details/bitsavers_sharpdataBationNotes_37682354/mode/2up

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 18, 2021, 12:06:29 am
content: Thanks all, I guess I just wanted to see a pinout for that 12 pin connector. I don't know if I need to provide the backplane drive or it makes it itself, there's a chip there that I can't find data on. There's a Vee=-20V handwritten note on the display as well, I guess I have to supply that somewhere.Anyhow, I've been dragging this thing around since I bought it in high school at the surplus shop, guess I can wait another three decades.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 18, 2021, 07:44:22 am
content: Hum there was some displays at the time who needed the characters controller, on your lcd you only have the column driversYou wont get anything out of it unless you add the controller SED1610F SED1630F as specified in the datasheet of the SED1600F

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 18, 2021, 01:31:25 pm
content: I don't think so. How would I access the glass to do that? It's a passive matrix, there are 8 80 bit shift registers on top which works out to 640 pixels, and the 6 on the bottom work out to 480. All you need to do is shift in 640+480=1120 bits (280 nybbles) to create a line of 640 pixels and select the row you want to "illuminate". Unless it's a gray scale panel and it's really 320x240 in some fancy 2x2 scheme to allow 16 gray levels. I doubt in 1986 they had commercial LCDs that had a horizontal resolution of 1120 pixels. I mean consider laptops of the era.On the other hand there is a suspicious vacant area where a PCB could definitely fit and there are indeed tabs that look like they are meant to hold a board, possibly to hold a higher level controller and a translator to whatever low-level format the panel needs. With that cable bridging the gap though, you can't easily add a board after the panel is assembled.So maybe raw 12 pin connector to a video controller, or it's a large character display with its own controller, absent here.There was a bundle of stapled datasheets with the panel; for Epson character displays...

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 18, 2021, 08:48:17 pm
content: Well, duh, that O vs 0 thing led me to simply not care about the symbol and found thishttps://pdf1.alldatasheet.com/datasheet-pdf/view/105695/SHARP/LM641521/+00W7-JVPGzSRcxRCzNDCz+/datasheet.pdf640x480 passive screen with a controller. I guess my panel is used there.It does show that it would be driven in the upper/lower fashion, with 1280 pixels shifted in and two rows energized, I guess. Interesting.