ILLUMINATED PICTURE FRAME

Abstract

A display apparatus comprising a frame adapted to engage and support the edges of a picture, a casing defining a cavity disposed behind the plane occupied by the picture in use of the apparatus, lighting device located in the cavity, a power source for the lighting device, wherein the lighting device comprising a linear array of light emitting diodes mounted in respective apertures in an elongate laminar support and arranged to provide backlit illumination for a picture located in the frame, the array being located in a tubular diffuser located in a light transmitting tube, the diffuser having a diameter less than the diameter of the tube, the tube being disposed axially of the casing; and wherein control circuitry and a battery compartment are enclosed by cover plates forming a channel to receive the lighting device.

Description

RELATED APPLICATION

The present invention claims priority to U.S. Provisional Application No. 60/821,970 filed Aug. 10, 2006 and entitled “ILLUMINATED FRAME APPARATUS” and is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Heretofore picture frames have not had adequate lighting. A need exists to provide for the same.

SUMMARY OF THE INVENTION

This invention relates to an illuminated picture frame of the kind wherein a picture, for example a photograph, drawing, painting, print or the like, hereinafter referred to as a picture, is mounted with the edges engaged in a frame and with a lamp or light located behind the picture to illuminate the image.

According to the present invention, a display apparatus comprises a frame adapted to engage and support the edges of a picture, a casing defining a cavity disposed behind the plane occupied by the picture in use of the apparatus, lighting means located in the cavity, a power source for the lighting means, wherein

• • the lighting means comprising a linear array of light emitting diodes mounted in respective apertures in an elongate laminar support and arranged to provide backlit illumination for a picture located in the frame,
  • the array being located in a tubular diffuser located in a light transmitting tube, the diffuser having a diameter less than the diameter of the tube, the tube being disposed axially of the casing; and wherein control circuitry and a battery compartment are enclosed by cover plates forming a channel to receive the lighting means.

In a preferred embodiment the light transmitting tube is cylindrical and the array is located in a tubular or cylindrical diffuser, the diffuser having a diameter less than the diameter of the tube so that the diffuser may be located within the tube, preferably resiliently deformed to be in contact with the inner surface of the tube.

Preferably, the lighting means extends actually longitudinally or laterally of a rectangular or square frame, the reflector being disposed symmetrically on either side of the axis so that the distance of the reflector from the plane occupied by the picture decreases with increasing distance from the axis. In this way, illumination is supplied to the lighting means in a substantially uniform manner across the length and width of the cavity.

In a preferred embodiment, the reflector is supported by cover plates, each cover plate being located parallel to the axis of the lighting unit and inclined towards the lighting unit to define a trapezoidal or curved channel within which the elongate lighting unit is axially located. The reflector serves to reflect light forwardly towards the picture and also serves to reflect heat emitted by the lighting unit away from the underlying power supply and control circuitry at the rear of the casing.

In a preferred embodiment, the power supply is located behind the first cover plate and the control circuitry is located behind the second cover plate.

The lighting means comprises linear arrays of light emitting diodes or other bulbs mounted in respective apertures in a laminar support. Preferably, the LEDs are mounted in straight line in apertures in an elongate insulating support. The support may comprise a narrow strip dimensioned to fit within the tube located across the length or width of the cavity of the frame. In a preferred embodiment, the laminar support has a multiplicity of axially arranged apertures, each aperture extending through a support to define a window to receive a respective LED unit.

In a preferred embodiment, the LED strip may be inserted into the tube at any angular disposition without detrimentally affecting the evenness of illumination provided to a picture located in the frame. This affords ease of construction and assembly during manufacture.

A reflector may be provided behind the lighting means. The reflector may comprise a metal sheet or film, preferably an aluminium sheet or a sheet of metallised paper or plastics material.

The diffuser and mounting tube may be secured at or adjacent each end by screw clips or other convenient fastenings. In preferred embodiments the ends of the tube and diffuser are open to allow dispersal of heat by convection in use.

The power supply may comprise a battery or an array of batteries. Alternatively or in addition a connection to an external mains or low voltage AC or DC supply may be provided.

A light sensor or photosensitive detector may be arranged to interrupt the circuit during bright light conditions so that the display is only illuminated during dusk or night time conditions to avoid wastage of the power supply.

In an alternative embodiment one or more outward facing surfaces of the frame or casing may incorporate or comprise a photovoltaic cell or an array of cells. Such an arrangement is adapted to supplement or reduce the need for a battery or external power supply.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described by means of example but not in any limitative sense with reference to the accompanying drawings, of which:

FIG. 1 is a perspective view of the device,

FIG. 2 shows the rear of the device,

FIG. 3 shows rotation of the fixing clips,

FIG. 4 is an exploded view showing assembly of the frame,

FIG. 5 shows the casing,

FIG. 6 is an exploded view of the casing,

FIG. 7 shows the control circuitry,

FIG. 8 shows the battery compartment,

FIG. 9 shows the sensor PCBA,

FIG. 10 shows the LED PCBA,

FIG. 11 shows a device including a solar panel,

FIG. 12 shows assembly of the light unit,

FIG. 13 shows the LED PCBA, and

FIG. 14 shows the circuit diagram of the device.

DETAILED DESCRIPTION OF THE INVENTION

The illuminated picture frame device shown in the drawings comprises a frame 1 composed of wood, plastics or other material. The frame may be rectangular, square or otherwise shaped. An easel back 2 is attached to a rectangular casing 3 secured to the rear of the frame. The casing is removably secured by rotatable clamps or clips 4 as shown in FIG. 3. The casing includes a box 5 adapted to receive a plurality of batteries 6, the box being closed by a removable door or cover 7.

The casing may include two attachments 28 for hanging the frame from a wall by means of a hook or nail.

A light sensor 8, an on-off switch 9 and a DC power jack 10 are also provided in the casing.

The mounting of the picture within the frame is shown in FIG. 4. An acrylic or glass cover sheet 11 is placed into the rebate in the frame and the picture 12 is placed onto the sheet. The casing is closed by means of an acrylic sheet 13 secured to the forward opening of the casing 3 by means of screws, clips or other fixings, and the casing assembly is secured in position by rotation of the clips 4. The casing forms a cavity to receive the lighting unit.

FIGS. 5 and 6 show the lighting assembly. A linear array of light emitting diodes 15 mounted in respective apertures on a laminar strip or printed circuit board 16. The strip is narrow and dimensioned to fit within a tubular diffuser 16. The strip is inserted into the tubular diffuser 17. The strip may be inserted with the diffuser at any convenient angular disposition. The diffuser is preferably resiliently deformed to be biased outwardly into contact with the inner surface of the tube. For example, the diffuser may be a spring fit within the tube. This serves to hold the diffuser in position during assembly and use of the frame. The diffuser is composed for example of opaque or translucent acrylic polymer or paper. The diffuser and lamp assembly is inserted into an outer acrylic mounting tube 18 secured to the floor of the casing by means of clips 19. Preferably the tube is disposed centrally axially of the casing. A reflective sheet or layer 35 is provided to direct radiation forwardly. The sheet may be composed of aluminium foil, other metallic materials or a metallised polymeric material, or paper.

In the illustrated embodiment, the lighting means extends longitudinally of any rectangular frame. In alternative embodiments, the lighting means may extend vertically within a rectangular frame or longitudinally or laterally within a square frame. The reflector 35 is disposed symmetrically on either side of the lighting unit so that the illumination is axially symmetrically even within the frame. The reflector extends from behind the lighting unit to a location against or adjacent the acrylic sheet 13 at the upper and lower edges of the reflector.

FIG. 7 illustrates the control circuitry of the device. A sensor PCB assembly (PCBA) is arranged to switch on the lamps when a signal from the light sensor indicates that the ambient light intensity has fallen below a predetermined value for example at dusk. The circuitry is enclosed by an inclined cover plate 27.

The battery compartment is shown in FIG. 8. The alkaline battery cells or rechargeable batteries 22 are received in a conventional manner between connector terminals and the assembly is enclosed by an inclined cover plate 24 which may be secured by screws or other fastenings.

The two cover plates 24 and 27 form a channel to receive the lighting unit to enhance reflection of light forwards through the picture in use. The cover plates are preferably located parallel to the axis of the lighting unit and are inclined towards the lighting unit to define a trapezoidal or curved channel within which the elongate lighting unit and reflector are located. In this way the reflector may be curved behind the lighting unit to provide even illumination towards the acrylic sheet.

The PCB assembly is shown in FIG. 9. A transistor 25 and microprocessor are mounted on a circuit board by means of screws (not shown) or fastenings.

FIG. 10 shows the LED PCBA. The PCB 30 has a plurality for example four apertures within which are mounted white LEDs 31 each LED having a resistor 32. The LEDs are disposed to emit light on both sides the PCB strip, providing a robust and economical arrangement.

FIG. 11 shows an alternative embodiment. This includes a solar panel of photovoltaic cells 33 so that the batteries are recharged during bright light conditions.

FIG. 12 shows assembly of the LED PCBA, diffuser and mounting tube, concentrically to form the lighting unit.

FIG. 13 shows front and side elevations of the LED array showing that the LEDs are disposed on each side of the PCB strip.

FIG. 14 is a circuit diagram. This shows the connection of the components of the illuminated picture frame of this invention.

Claims

1. A display apparatus comprising a frame adapted to engage and support the edges of a picture, a casing defining a cavity disposed behind the plane occupied by the picture in use of the apparatus, lighting means located in the cavity, a power source for the lighting means, wherein

the lighting means comprising a linear array of light emitting diodes mounted in respective apertures in an elongate laminar support and arranged to provide backlit illumination for a picture located in the frame,

the array being located in a tubular diffuser located in a light transmitting tube, the diffuser having a diameter less than the diameter of the tube, the tube being disposed axially of the casing; and wherein control circuitry and a battery compartment are enclosed by cover plates forming a channel to receive the lighting means.

2. Apparatus as claimed in claim 1, wherein a reflector is located behind the lighting means.

3. Apparatus as claimed in claim 1, comprising a light sensor or photosensitive detector may be arranged to interrupt the circuit during bright light conditions.

4. Apparatus as claimed in claim 1, wherein the frame or casing includes an array of photovoltaic cells.

5. (canceled)