When sourcing an automotive display overlay, do not ask the printed film to create an active privacy viewing angle. Put the liquid-crystal controller, polarizers, display electronics and mode logic under the display-module owner's scope. Put the printed border, opaque masking, icons, window geometry, surface finish, adhesive and dimensional tolerance under the overlay supplier's scope. Freeze the interface between those packages before quotation. Otherwise, each supplier may assume the other owns light leakage, misregistration or optical loss, and a sample can pass an appearance review while failing the installed shared and privacy viewing modes.
The August 20 display study puts privacy in the active optical stack
The Optica paper 80° Low-Twist Nematic Liquid Crystal Viewing Angle Controller for Unidirectional Privacy Protection of Automotive Co-Driver Displays was posted on August 20, 2026. The researchers proposed and experimentally evaluated a low-twist nematic liquid-crystal viewing-angle controller. Their work addresses off-axis light leakage through an active optical device placed in the display stack.
That study does not test a Baoshengda overlay, define a production vehicle specification or show that a printed film can produce the reported privacy performance. Its useful sourcing lesson is the boundary: the active viewing-angle function belongs to the display optical stack. A custom graphic overlay film panel can define the visible border, display opening, printed masking, finish and mounting interface, but it should not be quoted as the privacy controller.
Split the optical stack by owner before requesting prices
Create one responsibility matrix before sending drawings. Use the buyer's actual suppliers and specifications rather than copying the examples below.
| Interface decision | Owner to confirm | Evidence before quotation | Overlay supplier review |
|---|---|---|---|
| Shared and privacy viewing modes | Display-module owner | Optical stack, drive state and required viewing-angle test | Confirm that no printed claim replaces the active optical requirement |
| Visible display area | Vehicle HMI and display teams | Active-area drawing and keep-out zone | Set the overlay window and printed mask to controlled datums |
| Border light blocking | Overlay and display teams together | Allowed edge leakage and black-border target | Review ink system, print passes, registration and sample inspection method |
| Surface reflection | System optical owner | Gloss, haze, clarity and ambient-light method | Quote the specified film finish and provide material evidence |
| Overlay attachment | Mechanical and overlay teams | Bezel, recess, flatness, adhesive land and assembly pressure | Review die line, edge clearance, thickness and mounted sample plan |
| Installed acceptance | Vehicle integrator | Display-on and display-off views in both modes | Supply overlay samples and record overlay-specific dimensional and cosmetic results |
This matrix prevents a common quotation error. A supplier can price the visible overlay accurately only when the active optical function and the passive printed function are separated.
Freeze window geometry before finish and adhesive
Start with a common datum chain. Mark the display active area, the privacy controller outline if it extends beyond that area, the overlay window, the housing opening and the final cosmetic border. Add tolerances in both axes. A centered window in the artwork file can still be wrong if its datum does not match the display and bezel datums used in assembly.
Define the opaque border by function. It may hide inactive display edges, adhesive, fasteners or tolerance stack-up. It must not be described as the active privacy feature. Specify where the border may overlap the display, how its ink density will be judged and whether any backlight or display-on leakage is allowed at the edge.
Then lock the surface and adhesive choices. Gloss, matte texture, hard coat, antiglare treatment and film thickness can change reflection, image clarity and perceived color. Adhesive thickness, a recessed bezel, trapped particles or local waviness can change the air gap and create visible distortion. These effects must be checked with the real display and housing, not accepted from a loose overlay on a white table.
Prove the sample with an isolation sequence
Do not start with one assembled beauty sample. Use a three-step comparison that shows which layer caused a change.
1. Record the display module and active privacy controller without the overlay in shared and privacy modes.
2. Add the production-intent overlay with the specified window, finish and adhesive, then repeat the same views.
3. Mount the complete stack in the bezel or housing and repeat after the specified assembly pressure and environmental conditioning.
Keep camera position, ambient light, displayed image and drive mode controlled. The display team should own optical measurements such as viewing-angle performance, luminance, contrast and color. The overlay supplier should own window registration, printed-mask position, cosmetic quality, surface condition, adhesion and dimensional evidence.
Investigate failures by layer. A privacy-mode failure present before the overlay is installed belongs upstream. A dark border that intrudes into the active image points to window or registration error. Edge glow that appears only after adding the overlay may require a review of mask density, overlap or the installed gap. Bubbles, lift or waviness after mounting point to adhesive land, cleanliness, flatness or assembly pressure.
Where the overlay supplier stops
Baoshengda can review an agreed graphic-overlay construction, printed border and legends, display-window geometry, film finish, hard-coat request, adhesive die line, tolerances and physical overlay samples. The quotation can also identify what material certificates or sample records are available for the agreed build.
The display or system owner remains responsible for the liquid-crystal privacy controller, polarizers, backlight, display electronics, shared and privacy mode logic, optical performance limits, vehicle-level safety, cybersecurity, environmental qualification and regulatory validation. The cited research is current technical context, not a customer case or proof that any Baoshengda overlay delivers active privacy control.
Send a quotation package that exposes every interface
Include these items in one controlled package:
- display outline, active area and keep-out drawing;
- cross-section showing the display, active privacy controller, overlay, adhesive and housing;
- shared and privacy mode requirements owned by the display team;
- overlay window size, position, corner radius and datum tolerances;
- opaque-mask boundary, color target and edge-leakage inspection method;
- icons, legends, hidden areas and display-off appearance;
- film type, thickness, gloss or texture, hard coat, haze and clarity requirements;
- adhesive type, thickness, die line, edge clearance and housing surface;
- bezel recess, flatness, assembly pressure and cleanliness controls;
- operating temperature, UV exposure, cleaning agents and other vehicle conditions;
- isolation test sequence for the bare display, overlay stack and mounted assembly;
- prototype quantity, annual demand estimate and controlled revision identifiers.
When those boundaries are visible in the drawing set, send the automotive overlay package for sample and quotation review. The resulting price can then cover a defined printed and mounted part without transferring an active display function to the wrong supplier.
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