Open Frame LCD Displays: What to Specify Before You Build Them In

Short answer: An open frame LCD is a display sold without a finished housing — panel, backlight, driver board and a metal chassis with mounting flanges, meant to be built into something else. Vending machines, gaming cabinets, medical carts, ticket machines, shelf edges and museum cases all use them. Because the customer supplies the enclosure, the specification you need is different from a normal monitor: physical dimensions, mounting points, brightness behind your own front glass, and — the one that catches people out — how long the same model will stay available. Below is what to settle before you order.

1. What "open frame" actually includes

There is no single standard, so confirm the scope. A typical open frame unit is the LCD panel with its backlight, a driver board with video inputs, a power board or external adapter, and a sheet-metal chassis with threaded mounting flanges. What it does not include is a bezel, a stand, speakers in most cases, and any weather or dust protection — the enclosure you build provides all of that.

Some suppliers sell a bare panel plus a board kit and call it open frame. That is a different thing, and it puts the mechanical work on you.

Ask the supplier: "Does this include the chassis and mounting flanges, or panel and board only?"

2. Dimensions matter more than "size"

For a normal monitor, the diagonal is enough. For an integration it is nearly useless. You need three sets of numbers:

• Active area — the actual image, in millimetres, width by height. This determines your cut-out.
• Outline dimensions — the full chassis footprint including flanges and any board that sticks out.
• Depth — chassis depth, plus connector depth, plus the cable bend radius behind it. The last two are what make a unit not fit.

Ask for a dimensional drawing, in a CAD format if your mechanical team works that way. A supplier who cannot produce one is not set up for integration work.

Ask the supplier: "Can you send the mechanical drawing with active area, outline and depth, including connectors?"

3. Mounting: flanges, VESA, or both

Open frame units mount in one of two ways: side or rear flanges with threaded holes, or a standard VESA pattern on the back. Flange mounting gives a flush front against your own bezel and is the usual approach for a cut-out panel; VESA is easier if the display hangs on a bracket inside the cabinet.

Two details worth confirming: the thread size and depth of each hole, because a screw that bottoms out against the chassis will bow the panel; and whether the flanges are on the sides, the rear, or both, since that decides whether your enclosure can be assembled from the front or only from the back.

4. Brightness: your front glass takes some of it

An open frame display is almost always viewed through something — acrylic, tempered glass, a printed graphic layer, sometimes an anti-vandal sheet. Every layer costs light, and a tinted or textured sheet costs a lot of it.

A standard 350–500 cd/m² unit is fine behind clear acrylic in a shop interior. It is not fine behind a smoked panel, in a skylit concourse, or anywhere daylight reaches the front face. If the finished product will stand near glazing or outdoors-adjacent, specify a high-brightness panel at the start — retrofitting brightness means changing the display.

Ask the supplier: "What is the rated brightness, and what do you recommend behind a 3 mm acrylic front in a daylit space?"

5. Heat: you built the enclosure, so it is your problem

This is where integrations fail six months after launch. The display was tested on a bench in open air; in your cabinet it sits in a sealed pocket with a media player and a power supply, and the heat has nowhere to go.

Ask the supplier for the operating temperature range and the unit's power dissipation in watts, then design the enclosure to keep the panel inside that range at the worst ambient temperature the product will meet. Backlight life falls sharply as panel temperature rises, so a display that runs hot does not fail immediately — it dims over a year and then fails.

If the enclosure must be sealed against dust, plan conduction: mount the chassis against metal that can carry heat outward, rather than relying on air that cannot circulate.

Ask the supplier: "What is the operating temperature range and the power dissipation, and where is the hot spot on the chassis?"

6. Touch, if you need it

You can buy an open frame unit with touch already bonded, or add your own touch layer behind your front glass. Bonded is simpler and better optically. A separate layer gives you freedom over the front surface — useful if the product needs a specific glass thickness or an anti-vandal front — but you then own the alignment and the calibration.

If touch sits behind your own glass, tell the supplier the glass thickness before ordering: projected capacitive sensing has a limit on how much material it can see through, and it is typically a few millimetres.

7. Interfaces and control

Confirm the video inputs you need — HDMI and DisplayPort are common, LVDS or eDP if you are driving the panel directly from your own board. Then check the things people forget: whether the unit powers on automatically when mains is applied (essential for an unattended machine), whether the OSD can be locked so the public cannot change settings, and whether there is serial or network control for brightness and power scheduling.

Ask the supplier: "Does it auto-power-on after a mains interruption, and can the OSD be locked?"

8. Longevity: will this exact model still exist next year?

This is the question that separates an integration supplier from a display reseller. If you design a product around a specific active area and mounting pattern, a panel change means a mechanical redesign.

Ask what the expected production life of the model is, whether the supplier will notify you before a panel change, and whether a form-fit-function compatible replacement is guaranteed. For a product with a multi-year life, agree this in writing at the order stage rather than discovering it at the reorder.

Checklist (paste into your RFQ)

1. Active area: ______ × ______ mm
2. Outline dimensions including flanges: ______ × ______ mm
3. Total depth including connectors and cable bend: ______ mm
4. Mounting: side flanges / rear flanges / VESA · thread: ______ · depth: ______ mm
5. Rated brightness: ______ cd/m² · front glass: ______ mm ______ material
6. Operating temperature range: ______ · power dissipation: ______ W
7. Touch: none / bonded / behind customer glass (thickness: ______ mm)
8. Inputs: HDMI / DP / LVDS / eDP · auto power-on: yes / no · OSD lock: yes / no
9. Expected model production life: ______ · change notification agreed: yes / no
10. Mechanical drawing supplied: yes / no · CAD format: ______

How EKAA approaches open frame and embedded displays

EKAA designs and manufactures its own displays in Guangzhou, with CAD designers, engineers and dedicated production lines in house, and takes ODM and OEM work alongside its standard range. That means active area, chassis dimensions, mounting pattern, brightness, touch and interface can be specified to the machine the display goes into, and the mechanical drawings come from the team that builds the unit. Products carry CE, RoHS and FCC certifications depending on the line.