WO2019202347A1 - System and method of production of luminous letters - Google Patents

Abstract

A luminous letter contains of strips of LEDs mounted with its backs within a slot, that is centered in the front plate, thus emitting light towards a reflector on the back side of each unit, whereas the front cover is fully transparent. Each unit it is watertight due to cast flanges, energy-efficient and easy to maintain. For longer service life, the letter is dried in a vacuum chamber.

Description

System and method for production of luminous letters

FIELD OF THE INVENTION

The invention relates to illuminated advertising, and more exactly to kind of luminous signs for distant recognition and even more exactly to modern types consisting of LED-strips.

BACKGROUND OF THE INVENTION / PROBLEM TO BE SOLVED

LED lighting has been part of our everyday life for many years. It plays an important role in exterior lighting and as indicators in the control system industry. The product quality is de- fined in easy recognition from a longer distance, long life and easy maintenance and slow decay of luminosity. Therefore thermal management is mandatory to ensure longterm per- formance.

PRIOR ART

Hitherto LED letters are mostly cast of solid plastic, wherein a notch is milled on its backside to provide space for LED strips to be inserted. The LEDs are manually installed and con- trolled for uniform lighting and in case individually corrected.

A plastic sheet is then glued to the back of the letter to seal the sign. This step of connecting the front and rear flanges is performed manually. A variant for sealing the LED letter or the form is to insulate the LEDs tightly by casting it in. The front sides of the molds are hitherto covered with dyed foil. Thereafter, the side edges and, occasionally, the backside mostly is covered with an opaque or transparent layer.

By milling the forms much precious material is lost. Manual gluing of the backside on the mold often results in uneven lighting. Complete embedding of the LEDs has an impact on thermal stress within the luminous letter, which results in shorter service life.

Moreover, an undesired reaction between the glue materials and the LEDs can occur: By gluing the front side with a colored foil and painting the flanges can lead to a void even by small impacts. Moreover the impact of weather conditions can cause voids.

The lacquer layer, which is applied to the side edge, may also be a weak point, since it often is not sufficiently thick. The service for this design is a difficult and time-consuming process since the LEDs are difficult to access within the mold. TASK OF THE INVENTION

The object of the present invention therefore is to design a luminous letter in such a way that it is watertight, uniformly luminous, energy efficient, immune to overheating and permits easy service.

SOLUTION

LED stripes are attached to a slot, that is centered in the front plate or along the flanges. The light is emitting towards the inner / backside of the letter. The attachment of a reflective sur- face mounted on the rear ensures a constant and uniform illumination. Due to the reflection on the inner surface of the backside, the illumination of the letter becomes significantly more energy efficient since only about half the conventional number of LEDs is required to illumi- nate the letter uniformly.

In addition, this results in a significantly lower heating of the luminous letter, which can in- crease efficiency and longevity. By installing the LEDs in a slot, the exact position of the LEDs is known, which greatly simplifies maintenance and repair.

The final casting of the outer side of the form of the letter produces a very thick uniform layer, which reliably seals both the color film on the front side, the flanges and the back of the sign. This prevents voids on the entire form and prevents water from penetrating the luminous letters.

As the outer flanges are mounted, the letter must be dried in a vacuum chamber to make the sealing as tight as possible.

This production method allows automation of the entire manufacturing process and maintains constant quality. More material is saved. Higher light efficiency is provided and the letter is watertight.

DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a cross section of the luminous letter.

Light emitting diodes are installed along the LED strip (Fig. 1 No. 4), which beam into the interior of the letter. The rays are directed to the back (Fig 1. No. 7), the inside of which is coated with reflective material (Fig. 1 No. 5).

The light is reflected from this surface towards the front side (Fig. 1 No. 1), which allows a uniform illumination of the letter.

The LEDs will be sealed in a solid acrylic. (Fig. 1 No. 3). By casting the outside shape of the flanges (Fig. 1 No. 2 ), a solid layer will seal and cover the foil on the front, the flanges and the back-shape of the sign, resulting a solid and waterproof sealed illuminated sign. (Fig. 1 No. 2)

This is enhanced by a gasket, sealing the connection of the back-panel and the flanges (Fig.1 No. 6). The edges between the front foil and colored flanges are solid and not prone to damaging. At the end of production, the letter will be dried in a vacuum chamber to allow better sealing (Fig, 1 No. 8).

Claims

CLAIMS:

1. A luminous letter by LED strips, wherein the outer flanges are cast with another layer of plastics.

2. A luminous letter lighted by LED strips as to claim one, wherein the LED strips are

mounted within a centered slot, comprising a reflecting base and a transparent front.

3. A luminous letter lighted by LED strips as to claim one, wherein a gasket seals the con- nection of the back-panel and the side flanges

4. A luminous letter by LED strips as to claim two, wherein the base consists of a reflective layer.

5. A luminous letter by LED strips as to claim two, wherein the transparent top layer may be made of polycarbonates or similar plastic material.

6. A luminous letter by LED strips as to claim one, wherein the electrical lines are directly solded to the LED strips.