>> I'm wondering... Is there a specific *name* for this type of LCD?
>
> Passive matrix. As opposed to active matrix.

OK.

What about the blue/purple ones? You know, like they had on ancient 
laptop screens?

>> What does it cost to put one of these into your product?
>
> $1 would be my guess. You can probably find a bulk lot of 1000 on
> aliexpress or something.

Wow. I didn't expect it to be quite *that* cheap. Even a simple resistor 
costs more than that! (Or maybe it doesn't if you buy a thousand of 
them, IDK.)

> The most important thing to
> remember with any LCD type is that the *time-average* voltage across any
> segment must be zero, or you will damage the LC material.

Oh, that's interesting.

> If you've got
> a microcontroller or CPU already it should be easy to do in software.

Yeah, that's what I figured. And most electric devices with more than 
one button on them probably have a CPU already. (Probably...)

>> At the other end of the scale, you have the stupid-DPI full-colour
>> back-lit LCDs with touch sensitivity that they put into every mobile
>> phone, ever. What do *those* things cost? I'm guessing you need way,
>> *way* more hardware to drive it. (An entire framebuffer, for starters...)
>
> Price is roughly proportional to screen area (the factory doesn't care
> much how many screens it gets out of each "mother sheet").

Linearly proportional? Or is it "more expensive" to buy really big screens?

> For a 4"
> smartphone screen with touchpanel I'd say about $10. A laptop display
> could be $50.

OK. Again, that's not nearly as much as I thought. Makes me wonder why 

makes it a high-colour touch-screen device...

> Really the price depends heavily on the volume, who the
> customer is, whether it is a custom design/off the shelf, what
> additional electronics/touch is included etc.

I imagine touch would be really expensive - but IDK...

> In the world of very high volume mass production you can almost ignore
> tooling costs, so the cost is mostly made up of two parts: materials and
> assembly. A toaster might be a bit of bent steel with two plastic sides,
> you're talking $1 or so for those parts plus heating elements, wiring
> and some screws, so maybe $10 total?

I have a really cheap toaster somewhere that looks like that might 
literally be all there is to it.

I also have a more expensive toaster with a defrost mode, reheat mode, 
and automatic timing adjustment based on the bread thickness. Because 
when you press the lever, a pair of grills spring out and hold the slice 
in place, and (I presume) tell the microcontroller how thick the bread 
is. Also, the case is polished chrome with a two-tone paint job.

I don't know, but I'm guessing it must be reasonably expensive to 

something?)

> A switch on the other hand is like
> a complicated mini-assembly in itself, so although the material cost is
> very low, there is a high assembly cost, so a switch could easily cost
> $1 too. So you've got a total cost of $13 or $14 depending on how many
> switches you use. If you're expecting to sell a million toasters, using
> one less switch will make you $1m more profit :-)

Sure, but you don't *make* the switch yourself, surely? You buy an 
off-the-shelf microswitch, and then you just got to mount the thing 
securely and give it a nice-looking button that matches the casing. (?)

I agree, depending on production volumes, the profit difference might be 
large. ;-)

> How much profit do you think the manufacturer makes on a cheap washing
> machine?

That's actually an interesting question.


machine is one of those rare objects that contains *metal*. Obviously 

it. IDK, but I doubt it. The machine is also probably quite awkward to 
physically assemble. And they're large and heavy, so storing and 
shipping probably isn't cheap.


is pure profit. I guess there's enough people in the market that it 
can't be *that* profitable, but... IDK.

> Even if there were zero development costs, is it even worth
> them spending an extra $10 on a high res screen with touch panel?

I guess it's only really "worth it" if it makes more people buy them. I 
don't know for real how much extra money somebody would actually pay for 
a screen.

Then again, my washing machine [which I didn't pay for] has about a 
dozen lights on it, and 6 buttons. So the buttons can't be *that* 
expensive! (Well, for a _washing machine_ they probably aren't...)

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