Sony Reader - how to change its contrast ratio - Page 2

NatCh · 05-14-2007, 08:58 AM

"blue LED's all over"! That's hysterical!

No, I didn't add blue LEDs, I actually was hoping to get a part number off the stinkin' battery at the time.

Now that you mention it though, I did recently purchase a lot of 100 self-flashing RGB LEDs ....

Those are for a specific project, though: I have a small box that I put 16 single color self-flashing LEDs on about 7~8 years ago (like the computer displays in old 1970s movies, you know -- except mine all blink separately in a psuedo-random pattern created by the duty cycle variances of the individual LEDs), and I want to make it bigger and better, of course.

Unfortunately, I don't really have a place to work on it right now (in fact, I opened the Reader on my desk at work one day), and we're getting ready to move at the end of July, so I'm not starting projects that I can't finish in an hour or so these days. On the other hand, we're getting ready to move, and I hope to have enough space to set projects up and leave them set up 'til I complete them.

dstampe · 05-14-2007, 10:08 AM

I tried this out, with the following observations:

This resistor seems to be involved with ghosting control. Too far one way, and the menu background gets darker with each pointer movement--that is, "white" voltages start to darken the display pixels. Moving the pointer then leaves white ghosts on an increasingly black background. Moving it the other way leaves dark ghosts of the pointer, with the menu background staying white. That is, the inverted "negative" image does not seem to be clearing pixels.

The best setting seems to be just at the point where the cursor leaves no ghost, or just the faintest black ghost. It may take 10 or more pointer moves to see the white ghost, as the background darkens just a bit on each move. This setting does not seem to be too sensitive in terms of resistor position, 1/12 turn is about the threshold for a noticeable difference.

I found that the optimal setting was 1/4 turn counterclockwise from the factory setting. This did result in improved legibility, but noticeably more residual image when the reader was turned off.

BTW, I also took the opportunity to remove the chrome from the top surfaces of the side strips, and paint these black. That chrome is ridiculously bright compared to the black reader and dark display with my visual problems. Scraped it off with a razor blade, stone-age technique but none of the etchants I had would touch it.

diabloNL · 05-14-2007, 10:49 AM

Quote:

Originally Posted by NatCh

"blue LED's all over"! That's hysterical!

No, I didn't add blue LEDs, I actually was hoping to get a part number off the stinkin' battery at the time.

Now that you mention it though, I did recently purchase a lot of 100 self-flashing RGB LEDs ....

Those are for a specific project, though: I have a small box that I put 16 single color self-flashing LEDs on about 7~8 years ago (like the computer displays in old 1970s movies, you know -- except mine all blink separately in a psuedo-random pattern created by the duty cycle variances of the individual LEDs), and I want to make it bigger and better, of course.

That's really cool. Don't forget making some pictures when you start on this project.

Speaking of pictures. dstampe, do you have a picture showing what you've done?

NatCh · 05-14-2007, 11:43 AM

Quote:

Originally Posted by diabloNL

That's really cool. Don't forget making some pictures when you start on this project.

That'll be a while, but since you're interested, here's a short clip of the one I already have (it's in some goofy format that my Trēo uses

)

Latemarch · 05-17-2007, 10:02 PM

Quote:

Originally Posted by NatCh

No, I didn't add blue LEDs, I actually was hoping to get a part number off the stinkin' battery at the time.

Is there a replacement battery available?
Is the one in there soldered in?

My battery life stinks and the unit is out of warranty

HarryT · 05-18-2007, 02:14 AM

Please correct me if I'm wrong, but I thought that the warranty on the Reader was a year. No Reader is a year old yet, is it? It was only launched in - what? October?

NatCh · 05-18-2007, 08:11 AM

I thought the warranty was a year, but I'd have to go look.

@LateMarch: The battery has a connector -- it's not soldiered in -- but there's no part number visible on the thing, so while there may be (probably is) a replacement battery available somewhere we don't know what to look for.

diabloNL · 05-18-2007, 08:45 AM

Quote:

Originally Posted by NatCh

That'll be a while, but since you're interested, here's a short clip of the one I already have (it's in some goofy format that my Trēo uses

)

That's so..so..well..spacy.

I like it!

BTW there is a part number on the battery. Let me get it for you.

EDIT: Here it is.

NatCh · 05-18-2007, 10:01 AM

Quote:

Originally Posted by diabloNL

That's so..so..well..spacy.

I like it!

Glad you find it amusing. They're really not too hard to do, the biggest hurdle is the cost of the materials, mostly the LEDs. That one all the LED's are connected in parallel, so the power supply has to be pretty hefty. One of the things I need to work out with the bigger one is just how many I can put in series with which power supply, so I can get away from supplying some ridiculous amount of current -- I know how to work it out, and have the tools, but no place to actually do the work at present.

diabloNL · 05-18-2007, 10:34 AM

Quote:

Originally Posted by NatCh

Glad you find it amusing. They're really not too hard to do, the biggest hurdle is the cost of the materials, mostly the LEDs. That one all the LED's are connected in parallel, so the power supply has to be pretty hefty. One of the things I need to work out with the bigger one is just how many I can put in series with which power supply, so I can get away from supplying some ridiculous amount of current -- I know how to work it out, and have the tools, but no place to actually do the work at present.

I think the best is to make a combination of series and parallel. In that way you can put quite a lot on a decent P/S.

NatCh · 05-18-2007, 03:25 PM

That's more or less where I figure I'll end up, but I have to nail down the more and less.

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05-14-2007, 08:58 AM	#16
NatCh Gizmologist Posts: 11,615 Karma: 929550 Join Date: Jan 2006 Location: Republic of Texas Embassy at Jackson, TN Device: Pocketbook Touch HD3	"blue LED's all over"! That's hysterical! No, I didn't add blue LEDs, I actually was hoping to get a part number off the stinkin' battery at the time. Now that you mention it though, I did recently purchase a lot of 100 self-flashing RGB LEDs .... Those are for a specific project, though: I have a small box that I put 16 single color self-flashing LEDs on about 7~8 years ago (like the computer displays in old 1970s movies, you know -- except mine all blink separately in a psuedo-random pattern created by the duty cycle variances of the individual LEDs), and I want to make it bigger and better, of course. Unfortunately, I don't really have a place to work on it right now (in fact, I opened the Reader on my desk at work one day), and we're getting ready to move at the end of July, so I'm not starting projects that I can't finish in an hour or so these days. On the other hand, we're getting ready to move, and I hope to have enough space to set projects up and leave them set up 'til I complete them.

05-14-2007, 10:08 AM	#17
dstampe dstampe Posts: 50 Karma: 17 Join Date: Jan 2007 Location: Canada Device: Sony PRS-500	I tried this out, with the following observations: This resistor seems to be involved with ghosting control. Too far one way, and the menu background gets darker with each pointer movement--that is, "white" voltages start to darken the display pixels. Moving the pointer then leaves white ghosts on an increasingly black background. Moving it the other way leaves dark ghosts of the pointer, with the menu background staying white. That is, the inverted "negative" image does not seem to be clearing pixels. The best setting seems to be just at the point where the cursor leaves no ghost, or just the faintest black ghost. It may take 10 or more pointer moves to see the white ghost, as the background darkens just a bit on each move. This setting does not seem to be too sensitive in terms of resistor position, 1/12 turn is about the threshold for a noticeable difference. I found that the optimal setting was 1/4 turn counterclockwise from the factory setting. This did result in improved legibility, but noticeably more residual image when the reader was turned off. BTW, I also took the opportunity to remove the chrome from the top surfaces of the side strips, and paint these black. That chrome is ridiculously bright compared to the black reader and dark display with my visual problems. Scraped it off with a razor blade, stone-age technique but none of the etchants I had would touch it.

05-18-2007, 02:14 AM	#21
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	Please correct me if I'm wrong, but I thought that the warranty on the Reader was a year. No Reader is a year old yet, is it? It was only launched in - what? October?

05-18-2007, 08:11 AM	#22
NatCh Gizmologist Posts: 11,615 Karma: 929550 Join Date: Jan 2006 Location: Republic of Texas Embassy at Jackson, TN Device: Pocketbook Touch HD3	I thought the warranty was a year, but I'd have to go look. @LateMarch: The battery has a connector -- it's not soldiered in -- but there's no part number visible on the thing, so while there may be (probably is) a replacement battery available somewhere we don't know what to look for.

05-18-2007, 03:25 PM	#26
NatCh Gizmologist Posts: 11,615 Karma: 929550 Join Date: Jan 2006 Location: Republic of Texas Embassy at Jackson, TN Device: Pocketbook Touch HD3	That's more or less where I figure I'll end up, but I have to nail down the more and less.

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