Author Topic: KOPIN KD040922K-K micro sized LCD display (Read 4590 times)

kyndal · « **on:** November 05, 2019, 05:02:43 am »

Hi Guys. I'm trying to use / re-purpose a couple of KOPIN KD040922K-K 0,5" lcd's
but I'm unable to find any information on these tiny lcd's

from what i found online. it appears that the displays take some sort of RGB type analog signal? maby ITU-R 601 YCbCr (4:2:2) format?

I have reverse enginered a bit of it. and based on the board layout etc. it seems to have the 3 analog inputs for R,G,B
a couple more Im guessing could be H + V sync? but also another few signal looking pins.

the LCD has got a total of 20 pins

and that's about where I got to for now. unfortunately i do not have a working device, so I'm not able to look at signals at the moment...

does anybody on here have a bit on information on driving these things?
or similar analog input lcd's ?

I'm used to digital lcd's parallel, i2c, 24bit RGB etc.. but not what appear to be analog signal straight to the glass? (i could be wrong about this..)

EDIT: i think the lcd does not have a "driver" at all.. it is interfaced directly to the liquid crystal pixels. (analog RGB) with some sort of shifting logic
and inverting DC bias to maintain DC Balance.. the other input pins, probably for the control logic clock / direction ?
hm..

any information would be greatly appreciated

Rune Kyndal

coromonadalix · « **Reply #1 on:** November 05, 2019, 10:29:16 am »

Damn thats a small display

~~Weren't they used in some keyboards ??~~

Fraser · « **Reply #2 on:** November 05, 2019, 11:03:20 am »

I believe I have information on these as they are used in many thermal imaging scopes that I have worked on.

I can confirm that KOPIN miniature LCD displays are normally partnered with a dedicated KOPIN driver IC that does all the required signal processing.

I am not able to access my archives until Friday, but will do so if no one else has helped you before then.

The KOPIN driver IC datasheet was available on the internet when I last searched for it. I will see if my previous posts on repairing thermal imaging scopes contain the part number for you to search on.

Fraser

Fraser · « **Reply #3 on:** November 05, 2019, 11:09:29 am »

KOPIN micro display page is here....

https://www.kopin.com/lcd/

I found the ID of one driver IC used ..... KCD-A210. I will look for more and datasheet.

Fraser

Fraser · « **Reply #4 on:** November 05, 2019, 11:13:08 am »

KCD-A300 driver datasheet for general information.

https://datasheetspdf.com/parts/KCD-A300-QB.pdf?id=672941

Fraser

Fraser · « **Reply #5 on:** November 05, 2019, 11:20:26 am »

A cyber display data sheet for general information.

https://datasheet.datasheetarchive.com/originals/library/Datasheets-SW3/DSASW0041032.pdf

You need to be searching on terms like

KOPIN LCD
CYBERDISPLAY
KOPIN KCD

There are plenty of data sheets on the internet but they need the correct search terms to find them. I was not looking specifically for your part number as it could be an OEM part ID. I believe Google will turn up the required data though as KOPIN displays are quite common. The driver IC often covers a number of different LCD panels. There are both monochrome and colour LCD panels and these do use separate driver IC types as would be expected.

For info, FLIR use these types of displays in their thermal scopes. The tear downs of those scopes on this forum have pictures of the PCB’s containing a KOPIN driver chip.

Fraser

Fraser · « **Reply #6 on:** November 05, 2019, 11:23:13 am »

KOPIN A220 and 221 driver IC datasheet

https://datasheet.datasheetarchive.com/originals/library/Datasheets-SW3/DSASW0041288.pdf

Fraser

Fraser · « **Reply #7 on:** November 05, 2019, 11:27:20 am »

Advert for a similar display with driver PCB....

https://www.tekgear.com/rs170-oem-kit.html

Fraser

Fraser · « **Reply #8 on:** November 05, 2019, 11:30:32 am »

You may benefit from searching the KOPIN web site archives on the Wayback machine, as some of the driver datasheet URL’s for the KOPIN site are returning a 404 error as KOPIN have deleted them.

Way back machine may have the data sheets. I seem to remember downloading all I needed direct from KOPIN a few years ago.

Fraser

Fraser · « **Reply #9 on:** November 05, 2019, 11:50:18 am »

Your displays resolution appears to be the 640 x 480 pixel model

https://www.rcgroups.com/forums/showthread.php?1258125-UK-FPV-Thread/page3302

Fraser

Fraser · « **Reply #10 on:** November 05, 2019, 03:47:37 pm »

The controller for your display looks to be shown on this page from the KOPIN archives. Only one controller is shown for an LCD panel. It is an SSD1502.

https://web.archive.org/web/20120723054453/http://www.kopin.com/vga/

https://www.electronicsdatasheets.com/manufacturers/kopin-corp/parts/kcdvdcfaa#datasheet

https://www.electronicsdatasheets.com/manufacturers/kopin-corp/parts/kcda900qa#datasheet

More data sheets....

https://www.electronicsdatasheets.com/manufacturers/kopin-corp/parts/

Fraser

Fraser · « **Reply #11 on:** November 05, 2019, 04:00:30 pm »

In case you have not noticed, the part number details the total number of pixels .... H x V x 3 (3 pixels for colour)

So a QVGA is 320 x 240 x 3 = 230K pixels and so the part number includes “230K”.

And VGA is 640 x 480 x 3 = 922K and that is your LCD park number ID “922K”

Fraser

Fraser · « **Reply #12 on:** November 05, 2019, 04:08:41 pm »

I just found the confirmation of the driver on a forum. Your MyVue glasses should contain the SSD1502 driver that is capable of driving two LCD panels.

“ I’ve the opportunity to examine these glasses currently, and the resolution is indeed 2*3*640*480, using two Kopin CyberDisplay VGA modules. The display driver chip (SSD1502) ”

Fraser

Fraser · « **Reply #13 on:** November 05, 2019, 04:10:16 pm »

OK, my mission is accomplished... here is the full datasheet for the SSD1502 that you need for driving your LCD panel.

https://opendevices.ru/wp-content/uploads/2011/06/SSD1502.pdf

Fraser

kyndal · « **Reply #14 on:** November 05, 2019, 04:56:23 pm »

WOW thanks Fraser. that's alot of good information thanks alot.
now i have some material to work with

i do have the pendent for the LCD's but no joy is escaping from it as of now.
i believe it got fried with an over voltage on the usb port. the power adapter is outputting a nice 9volts under load
how far down the line is unknown.
(thou shall measure voltages..) I'm finding nice 1.8v and 3.3v rails based on the TW9910 datasheet atleast will do more digging today

i still dont have the datasheet for the LCD part. but i have (decided) for now, that this pinout makes sense (from KCD-VDCF-AA datasheet which could be this device too)
and based on board layout

1 VCOM Pixel common electrode
2 RSV Reserved output
3 VIDR Red video input
4 VIDG Green video input
5 VIDB Blue video input
6 HCK1 Horizontal clock
7 HCK2 Horizontal clock
8 HST Horizontal start
9 RGT Left-to-right scan
10 DWN Top-to-bottom scan
11 VCK Vertical clock
12 VST Vertical start pulse
13 EN Row enable
14 SLEEP* Sleep mode
15 VDD Supply = +9.5V
16 VCC Interface supply = +3.3V
17 VSS Supply = 0V
18 TOUT1 Test output
19 TOUT2 Test output
20 VCOM Pixel common electrode

it looks like quite the exercise to drive the LCD "RAW" with the high and low going analog signals, "scan lines" etc.
just maby i can resurrect this board.

Rune Kyndal

kyndal · « **Reply #15 on:** November 05, 2019, 10:01:55 pm »

did some digging today.

the MUX-0 on my TW9910 chip got fried. it would not recognize a composite input

moving the input to mux-03, and swapping to that input in the register over i2c got it the TW9910 to register the input. and start spewing out data in YCBCR 422 format

the SSD1502 is putting out analog RGB to the the LCD, which lights up all white.. no picture though.

the 9v and 3.3v inputs on the lcd boards where dead, so i manually powered those. still no luck

looks there has been a bad voltage reach the LCD's this may be the end of the road

the RGB signals comming out of the board to the LCD is in the 1V PP range. it should vary between around 2+ <-> +9v with common being about 5v
so i tried feeding some signals into the lines... no luck.
so... there are a few things going wrong here i think im going to call it for now.

oh well. well spend weekend tinkering

Rune

rhodges · « **Reply #16 on:** November 06, 2019, 01:26:45 am »

If you would like to try again with a 320x240 display, you can get more here:
https://www.goldmine-elec-products.com/prodinfo.asp?number=G19051

The current price of $5 is insane. They go on sale for a fraction of that. Just wait and get a better price.

I looked at the data sheet and decided it was not worth any electronics and programming, even if it it were free. If a box of them appeared on my door, I would just put them in the trash.

kyndal · « **Reply #17 on:** November 06, 2019, 09:24:15 am »

Ya.. they do seem tricky to drive, without the right controller.

trouble is.. im working on something that needs a 0.5" LCD, i have a 0.49" AMOLED but 32x64 pixel is just a tad shy of the target

Rune


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