[Hardware Hacking General] duckdodger24th:
My Core Question:

WHY do no Android tablets have video INPUTS on them, so they could also be used as portable HD screens?

(or better yet as portable HD, multi-touch screens)

Basic Idea:

I want an Android Tablet that can ALSO do what the GeChic on-lap 1002 can do (even if that didn't include touch). The on-lap 1002 is a highly portable 10" 10-point touchscreen that plays video from any HDMI source (or vga with included adapter). It is powered by USB plugged into either a usb-charger style wall adapter or directly into a PC. The best part is that if it is plugged into a PC, it not only draws power there but also sends touch commands to the PC through the USB at the same time. Great for portable gaming or a second screen BUT they are about $250 for the 10" and about $400 for the 15.6" and they have no OS, or stand-alone capabilities at all. I want a tablet that is always useful as a stand-alone, but when the situation calls for it, can also do the on-lap's job! (If on-lap still isn't clear to you then here is a video of it's big brother the 15.6" version).

[YOUTUBE]p9v9kBTx-74[/YOUTUBE]

I realize that adding a feature can increase the price and/or size of a tablet, but MOST of the parts that they both use overlap, so I don't think that the increase in either would be all that big. An HD 10-point capacitive touch screen has to be the biggest part and single cost in both (so making one screen do both functions only makes sense for size and cost) and the same USB components could be used, same body, bezel, buttons, etc. Admittedly, some components would probably have to be modified like the screen control board. That might cost a bit more/be a little bigger as a combo item, but still shouldn't be anywhere near double sized or double cost... so go ahead and add a little bit of cost or a few millimeters of thickness if that's what it takes! I would gladly pay an extra $50-100 (and probably willingly pay a fair bit more) for a tablet to add this feature and that certainly SEEMS attainable.

I have done literally days worth of Googling and have read MANY threads (some in this forum) with people asking

IF

there are any tablets with an HDMI input. At this point I am 99.999% convinced there are NONE (but I would be VERY HAPPY to be proven wrong). In order to be 100% sure and let my brain rest... I just have to have some idea WHY doesn't it exist? I am hoping that some of the hardware experts and creative-minded modders that frequent this forum can help me understand what I'm missing or better yet help make it happen. THANKS IN ADVANCE TO ALL!!!

Some Clarification:

1.) I just want to re-enforce that I am asking about INPUTs, not outputs. You wouldn't believe how much confusion there was about the difference in a few of the threads I read on some DSLR sites ;)

2.) HDMI seems like the logical choice, so I may use it in examples, but my question is really about ANY video input regardless of port-type.

3.) I know that video ports only serve as EITHER a video input or output, not both from the same port (Some day a single port that did both would be nice, but for now) couldn't a tab easily have 2 ports, one in and one out or am i missing something simple?

4.) There is one answer I DO NOT BUY. Which is that 'there is not enough demand for anyone to bother adding an input to a tablet'. I have read several threads that have asked if it exists since 2011 for everything from DSLR photographers, gamers, car-PC builders, RaspberryPi fanatics, techs that want a portable workstation to connect to servers etc etc etc. Whole product lines or even companies (like GeChic) are based on portable screens, so I don't accept the premise that there is no demand. Besides, even if there WERE small demand, that would explain why they DON'T ALL have it, not why NONE have it. All I can conclude is that I am missing something and it must be a much bigger hardware challenge than I realize.