Display multiple messages using Prism technology

PRISM SIGNS Display multiple messages using Prism technology

Prism signs are an effective way to display multiple messages. Using rotating planks of aluminium to display up to four different messages, these can be designed to suit any requirements for urban or interurban applications such as warning of diversion routes or road closures, semi-permanent pedestrian zones or where pre-set messages are needed to alternate.

The product range offers solutions with internally illuminated prisms of 100mm or 200mm sections within a ‘closed’ enclosure behind a polycarbonate screen or ‘open’ prisms and can be presented vertically or horizontally depending on the application. The corrosion free aluminium sign enclosures are protected up to IP54 and can be co-ordinated to your colour requirements.

Due to their extremely low power consumption, prism signs are also ideally suited for solar power supply: energy is almost only required during message rotation.

These robust signs are built to withstand adverse weather conditions and require little maintenance, which makes them ideal for use in remote locations.

Sinusoidal drive:
A special feature of SWARCO’s prism signs is the sinusoidal drive which controls the message changes: starting with a high momentum, increasing speed during the process, and slowing down at the end of the motion phase, ensuring exact prism alignment. The drive then locks the prisms to protect them from external influences such as high winds. As well as optional temperature-controlled de-icing cycles the sinusoidal drive process considerably helps reduce mechanical wear and tear and maximizes the sign’s life span. The signs also feature a local override in the event of a power failure or for maintenance purposes. 

Linear drive:
Alternatively, for smaller variable surfaces, linear drives are used. Here, the prisms are driven by means of a wear-free worm gear, directly on the prism.


Weather Proof
and Durable


High Energy-


Made with precision



Technical Details

Sign housing:

Depending on the design, the sign housing consists of an aluminium-lined frame or a surrounding aluminium tray. Large-area service doors allow easy access to all service-relevant parts.

Static sign section:

The static sections of the variable message sign are realized in DAMBACH Alform technology, ensuring the visual impression for the driver is identical with that of a static signpost.

As with static traffic signs, the messages are made of reflective foils with the reflection classes RA1, RA2, RA3A, and RA3B.

"Closed'' version:

In the case of the ''closed“ version, the prism section is covered with a plexiglass panel-mounted flush with the front of the housing. It is typically internally illuminated at night,and an integrated heater prevents the front panel from fogging up. Similar to static traffic signs, the images are realized via non-reflecting foil (Type N) or in reflection class RA1.

Mechanical image return for additional safety:

As an additional option, SWARCO prism signs can be equipped with a spring powered mechanism ensuring the sign always returns to a predefined message in case of a power outage. Once power returns, the spring energy store is autmatically ''recharged“. The mechanical return device, developed by SWARCO, is protected by a European patent (Patent No. EP 15 96 352 B1).

Actuation variants:

Commands and feedback via switching contacts

RS 485 serial protocol

Without controller (end switch and motor wired to terminals)

Motor protection and timing element

Anti-Frost Control :

If equipped with proven SWARCO controllers and temperature sensors, a de-icing procedure is possible: for temperatures below 2°C, prisms are rotated by about 10° in a forward and reverse direction at a programmable time interval (normally, every 60 minutes). This prevents prism bearing freezing and the formation of continuous ice layers on the prism surfaces.