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Inquiry about 5inch LCD afterimage phenomenon
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Inquiry about 5inch LCD afterimage phenomenon

by HyunCheon on Mon Dec 10, 2018 11:47 pm

- Product : HDMI 5" 800x480 Display Backpack - With Resistive Touchscreen
- Order No. : #1905564-7019837550 (2EA)
- Purchase date : November 20, 2018

I am using your company's 5 inch HDMI touch LCD product. I've used the same three products before.
Recently purchased products are showing a new phenomenon not seen in previous products.
The operating system you are using is using raspian and you are uploading and running your own developed UI program.
- Version : Linux raspberrypi 4.14.79-v7+ #1159 SMP Sun Nov 4 17:50:20 GMT 2018 armv7l GNU/Linux

The following symptoms appear on the LCD screen.
If you change to another screen after displaying the window screen for a few seconds, the old screen remains as a residual image.
Of course, this happens not only in our program, but also in raspian linux itself.

We think this is a very serious issue because the LCD is a component attached to the product we provide to our customers.
Please answer any technical problems or causes, solutions, product exchanges, etc. regarding the above phenomenon.
I hope you get your answer that there is a positive solution.
Thanks.
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HyunCheon
 
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Re: Inquiry about 5inch LCD afterimage phenomenon

by oesterle on Tue Dec 11, 2018 12:06 am

Hi, HyunCheon!

Image persistence, also known as image rentention is common with LCD displays, and usually temporary. It can be avoided by using a screensaver when idle. (It's also an issue on other display types, including OLED, plasma, and CRT.)

Cheers,

Eric

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Re: Inquiry about 5inch LCD afterimage phenomenon

by HyunCheon on Tue Dec 11, 2018 1:07 am

Hi, Eric !

First of all thank you for your reply.

Of course I know the momentary afterglow that you commented on.
The symptoms I am asked are not the usual temporary afterimage problems. Even if the previous screen is displayed only for a few seconds, it is a problem that the afterimage is left for 1 minute or more until it disappears slowly.
And I have already mentioned in previous posts that no other LCD products show this phenomenon at all. Also, this phenomenon did not appear in the same product that was used before.

Thanks.

HyunCheon Shin

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Re: Inquiry about 5inch LCD afterimage phenomenon

by adafruit_support_carter on Tue Dec 25, 2018 9:59 pm

The fact that you have a custom UI adds a layer of uncertainty if the problem is the display or something else. Do you also see the ghosting with default Raspbian UI elements? Try launching a text editor that has black text on a white background. Type some letters then delete them. Do you get a similar residual effect with the deleted letters?

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Re: Inquiry about 5inch LCD afterimage phenomenon

by HyunCheon on Wed Dec 26, 2018 12:45 am

Yes...
Raspian linux also shows the same thing.
In the last inquiry, the number of image attachments was limited and I could not upload it.
I will also send the original video file showing this phenomenon.
Please download and confirm it via the link below.
http://gofile.me/6oR05/doserFGgQ

I will wait for your reply after confirmation.

Thanks.
HyunCheon
Attachments
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Re: Inquiry about 5inch LCD afterimage phenomenon

by adafruit_support_carter on Wed Dec 26, 2018 12:34 pm

You are getting this on *all* of the recently purchased displays?

Can you also try a pure console screen - no Raspbian desktop.

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Re: Inquiry about 5inch LCD afterimage phenomenon

by HyunCheon on Wed Dec 26, 2018 9:48 pm

Yes. Both LCDs purchased recently have the same symptoms.
However, one of them is only a little bit afterimage time.

If the lcd persistence problem persists even on basic Raspian linux, I can not apply it to our products in the situation that we have to display our application on LCD using GUI. Is not it a problem of LCD, of course?
I do not know what the test request means to us on the pure console you requested. Please let me know if you can not give a clear answer anymore, and if the test is absolutely necessary.

If it is normal for other products of your company, and there are afterimages only for the products we buy, I want to exchange for defective products.
Please give me your opinion on my opinion.

P.S.)
After today 's day, I will not be able to contact again this year. I will try to contact you again next year.

Thanks.
HyunCheon

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Re: Inquiry about 5inch LCD afterimage phenomenon

by adafruit_support_carter on Thu Dec 27, 2018 12:09 pm

I do not know what the test request means to us on the pure console you requested. Please let me know if you can not give a clear answer anymore, and if the test is absolutely necessary.

For example, if you used Raspbian Lite instead of Full.

After today 's day, I will not be able to contact again this year. I will try to contact you again next year.

That's OK. Sorry for dragging this out. But we haven't seen this before, so hoping maybe we can figure out what is happening. We will replace if it turns out to be something with our hardware.

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Re: Inquiry about 5inch LCD afterimage phenomenon

by HyunCheon on Mon Jan 07, 2019 9:57 pm

Hi!
I contact you for a long time because of our busy work.

We do not care if you have a persistence problem in pure console mode that you requested.
The problem is that symptoms that did not occur in your previous purchase of the product will appear in your recent purchase.
We have to use it in the GUI state.
Did not you check on the symptoms we had previously reported through videos and images?
So far we have not been able to supply this product to our customers.
I want to exchange or refund this product so that you can test it and identify the problem.

I will wait for your reply.

HyunCheon
 
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Re: Inquiry about 5inch LCD afterimage phenomenon

by adafruit_support_carter on Wed Jan 09, 2019 2:53 pm

OK. We don't know what this is. We would can replace these but would also like the problematic ones back so we examine them. Are you in the US?

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Re: Inquiry about 5inch LCD afterimage phenomenon

by HyunCheon on Wed Jan 09, 2019 9:13 pm

No. I'm in Korea.
If necessary, I can send the LCD modules to you through the Korean reseller.

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Re: Inquiry about 5inch LCD afterimage phenomenon

by adafruit_support_carter on Wed Jan 09, 2019 9:37 pm

We can only RMA within the US. Let's just replace your displays.

Send an email to support@adafruit.com with a link to this forum post and they can help you.

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Re: Inquiry about 5inch LCD afterimage phenomenon

by HyunCheon on Wed Jan 09, 2019 10:19 pm

OK.
Please tell me how to exchange displays.
If possible, it would be nice if you could proceed with the exchange procedure through domestic vendors.
What is your opinion on this?

And since we are currently using the LCD module for testing, we can return the new replacement first. Is it possible?

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Re: Inquiry about 5inch LCD afterimage phenomenon

by adafruit_support_carter on Wed Jan 09, 2019 10:23 pm

Ask those questions also via email to support@adafruit.com. They will be able to help you with what options are available.

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Please be positive and constructive with your questions and comments.