• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

LCD

Status
Not open for further replies.

dpswmb

New Member
I would like to investigate the feasibility of fabricating an automotive display which uses a graph and numeric displays. I have searched the web for several hours and have finally found this site which would appear to have some really smart guys. I need some help!

Front Glass. The the original display measures approximately 3.5" x 5". The front glass substrate is approximately 1/16" or 1/32" thick and is tinted on the back side which is then bonded to a second piece of glass.

Back Glass. This second piece of glass is essentially the same size as above except the top and left hand side is about 3/16" smaller (you can see the crystal ribbon sections in this portion on the top and sides). The original display used this indented area to attach sections of a two-sided 1/8" thick by 1/2" tall rubberized strip conductor(?). This rubberized conductor seems to have an embedded powdered material sandwiched in the center. This section of glass has the semi-invisible crystal circutry imprinted on it. It was then bonded/sealed to the front glass.

Back Side/Back Glass. Finally the back side appears to have a thin opaque black film sealed to the glass. The "graph bar and numerics and the digital numeric boxes have been left clear.

Remainder of assbly. This completed display is then place against colored templated, a 1/2' thick clear piece of plastic and then a piece of very opaque white thin plastic sheet.

Anyone that can help please jump in or email me direct. I am not an engineer. Degreed in Math, very familiar with screenprinting, and an exceptionally patience and oriented guy. Thanks--just get me pointed.

Have the ability to post picture(s) to my web address for those that can help.

Bill Belton, Texas :?:
 

Mosfet

New Member
Greetings dpswmb,
To clarify you say, 'fabricating an automotive display',
and then give a lot of specifics on it's size and appearance.
Where did this display come from?
If it's already a part of your car then the manufacturer should have it's electrical specifics.
If you wish to analyze a 'mystery device' - good luck sir.
Perhaps you wish to use the various automotive sensors and make your own display.
This is a large enough task I would use a LCD whose properties are well known.
Here is a site that sells LCDs which have standard interfaces: http://earthlcd.com/
They may even be able to identify the LCD you mention in your post.
I would recommend a small serial-driven graphic LCD and an embedded microcontroller.
Regards
 

dpswmb

New Member
Mosfet, thanks for the interest. The part is a dash speedometer display which came on Corvettes in the 84 to 89 era. I am a corvette restorer (58, 72 convertible, 84, and 90) and have become very familiar with the availability of original parts, reproduction parts and the prices they bring. Problem on some items is that they are discontinued or nearly extent when a replacement is needed. This "dash" display is such an item.

The particular panel on this 84 corvette was not very high tech compared to things today. It might have been at the time but certainly not now. The complete dash assembly consisted of two giant boards (which could probably be put on a stamp today) and structural housing to encase it. For the true restorer, you need an item to appear and perform as the original. My hidden agenda might be that I would like to semi-mass produce as I am not the only guy who has this problem. So, the process of creating the LCD is what I really need to know and if a cottage type industry can achieve this. It might not be easy but I have to believe it is doable. I just need info and sources. Bill Texas
 

Mosfet

New Member
It sounds like the original LCD is a 'dumb' device, all the processing done at the 'two giant boards'.
You might read: http://www.idavette.net/hib/diageqp.html
Your two giant boards seem to refer to 'powertrain control module' or PCM.
"All 81-’97 Corvette PCMs also transmit [diagnostic control codes], along with other information related to the on-board computer system, over 'serial data' lines which have a pin or, in later years, pins in the [diagnostic link connector]. To read this serial data you need a scan tester or other computer device."
Many microcontrollers read serial data, store the information and can format the data to graphic and numeric display on a more common LCD.
 

dpswmb

New Member
Mosfet, thanks for the great link to the Idaho articles. Good info that I had not read before. Not trying to drag you through the mud on this thread. Yes, the corvettes have several digital components and one is the electronic brain which controls just about everything on the car. It does have a diagnostic link as many of the other newer brand cars now have too. Attach a device to it and read the codes to find your problem.

The problem I want to solve is a totally separate issue. The displays on the dash cluster crack, get sunburnt or just need to be replaced sometimes. Kind of like breaking a single pane in your window--you don't want to replace the whole window when you can just put a new piece of 8"x11" glass back in. In the corvette case--they don't make the replacement displays nor do they even make or have stock on the original total and complete dash cluster assembly.

The digital dash display cluster is a separate unit housing the two giant boards which process info regarding 1-speedometer, 2-fuel gage/oil temp and press/coolant temp, and 3-tachometer graph displays. These thress areas each have a dedicated and separate "really dumb" LCD display. The liquid crystal glass plate is nearly an invisble crudely printed circuit layout. Through the use of some back lighting and pressure contacts with the main board, the liquid crystal areas.

So, if I knew what I was talking about, I would tint a piece of glass, print liquid crystal lines/patterns on another piece, bond the glass together, print a black block out artwork on the back and attach some rubberized conductors which press against the main boards copper ribbon pin-like connectors. Then I would replace the broken piece with the one I made and let the rest of the electronics continue to function just as they have always worked. Problem is "can you really make an LCD of this rather crude nature or do you have to be an LCD manfacture in Japan or China to achieve this? "

I made a solar cell and a crystal radio in high school science in 1964 and it worked. Where can you get info on how to make an LCD? Would you know? Bill :lol:
 

dpswmb

New Member
Mosfet, once a guy gets you zeroed in you are the man. The info is exactly the kind of stuff I was looking for. I know I will have to research other processes but I bet I can make these things if materials are reasonable available. Best part to me at this point is that the panels used in the cars are not matrix/pixel based type displays. They are more of a race-track or highway system layout which runs the glass. Color is achieved by a front colored transparent film. Pretty crude layouts--1-digital section which changes numeric readout in MPH and filtered with a yellow overlay 2-speed graph bar which is colored green and with corresponding static numeric numbers and they lite much like a thermometer rising while the digital display changes with exact numbers.

Bet I complete this thing unless I need crypton laser invisible molecules! You have been overwhelmingly helpful. Thanks very much. bill
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top