[R][T] Slide-out screen shortlist: Blanview 3.5" or Transmissive 3.4"

A project log for Tetent [gd0090]

A water resistant, 300WPM input peripheral for end-to-end workflows.

kelvinakelvinA 05/31/2024 at 07:500 Comments

Screen shortlist

I tried to find some options that could fit on the side of Tetent (like many of the past concepts) but it makes little sense from both an ergonomics and bundle adjustment perspective.

I'm going to be designing a square GUI for a better Tetinerary solution, and that allows for these options:

The top listing title has a typo. It should read 480x640.

Coming in at the same price as the first transflective screen, but without the £7 delivery charge, the 3.5in Blanview is the best available in LCD technology, featuring all the benefits and little of the drawbacks:

Looking at the top graph, it seems that the backlight uses 40mW in bright ambient lighting conditions. In stark contrast, the transmissive, 1000 nits 480x480 panel (KD034WXFPD002) uses 768mW and the transflective 480x640 panel (FS035VG083-C035A) uses 372mW. Both these values are right on point to what the graph shows.

One of the benefits of the 480x480 is that the GUI would look slightly larger, and that 2 panels is the same price as a single Blanview panel. However, as mentioned in the Bundle Adjustment log, I could develop with the entire 640x400 resolution found in the prism with the Blanview.

I thought that the image with the partially shaded panel was impressive.

Considering that my (not so temporary) "temporary" keyboard has now been in use for about 3 years, I think it's in my best interest to just go with the better panel upfront.

Slide out screen?

So this is all well and good, but the issue is actually placing the screen somewhere. As I've said in a Tetrinsic log somewhere, I had a "sigma" character inspired design. What I haven't yet mentioned was that I found a new belt type (5PH) and considered a 15x150mm Tetrinsic (with a 15mm diameter body, 46mm rotor length, custom motor), but there is only one type of 0 - 500g FSR available on the market and all the 15mm strip ones are 20 - 10000g, so much less likely to work well for this application. That 0 - 500g FSR has a max sense length of 85mm. The 5PH284 belt is the most ideal.

Top: Sigma style design. Bottom: Tetrinsic with 284mm belt and bracket style design.

In pursuit of thinness, I made the bracket-style design. The main benefit is so that it can fit in a pocket. The easter-egg benefit is so that I can design an RC tracked vehicle mode:

This is £65 on aliexpress, so maybe it's not entirely financially unjustifiable for Tetent to have a similar feature? 4 tracks with RGB LEDs and potentially even traction control? That sounds like a Pro remote controlled vehicle.

Since Tetent was also a bit of a stop-gap to Tetinerary, I did consider doing things the Apple Magic Mouse way and mount the screen on the bottom:

The charge port will be on the side though, like a usual mouse.

However, there may be a way to do the inverse of the PSP Go, where the screen slides out from under the input panel instead of sliding out to reveal the input panel. If I decide to focus on the 1 : 1 GUI, I could also employ a LG Wing strategy, where the screen swivels out.

The engineering challenge is going to be to fit a screen, 3Ah battery, 2 speakers and a PCB into a thin formfactor.