Magnetically operated display

Abstract: A magnetically operated display unit (2) includes a frame (4) with a color, a plate (22) pivotably mounted on the frame and including a first surface with a color different to that of the frame and a second surface with a color identical to that of the frame, a magnet (26) embedded in the plate, a U-shaped ferromagnetic element (8, 17) mounted on the frame so that two tips of the magnet (26) are located between two tips of the U-shaped ferromagnetic element (8, 17), a solenoid (16) mounted on the U-shaped ferromagnetic element and a light emitting diode (12) mounted on the frame. The plate defines a cutout for receiving the light emitting diode and one of the tips of the U-shaped ferromagnetic element. The light emitting diode includes a tip located on a level between the plate and the tips of the U-shaped ferromagnetic element. Two opposite currents are selectively directed through the solenoid.

Description: This invention relates to a magnetically operated display. Eye-catching displays are becoming more and more popular due to increasing consumerism and the desire for public awareness of products, public announcements etc. A first conventional display includes a matrix of light emitting diodes (LEDS) wherein various groups of the LEDS in the matrix can be selectively turned on simultaneously to present various images. The first conventional display performs well in an environment with a low level of light. However, the efficiency of the first conventional display is considerably reduced if the level of light is increased, for example, a sunny day, and the noticeability of the display is impaired. A second conventional display includes a matrix of magnetically operated display units each including a magnet embedded in a pivotable plate including a first surface with a color different from that of the remaining portion thereof and a second surface with a color identical to that of the remaining portion thereof. The second surfaces of different groups of the pivotable plates in the matrix are selectively exposed to view so as to show different images. The second conventional display shows clear images in a bright environment, however, visibility of the first surfaces of the pivotable plates is greatly reduced in the dark as the first surfaces of the plates do not produce light. In order to overcome this problem it was proposed to provide the pivotable plate type magnetically operated display units with individual light sources arranged behind the plates in such a manner that the light shines through small cutouts in the plate. Such a device, in which the light sources are optical fibres, is shown in EP 0556954 Al. A similar design, but using a different type of flip-over drive for the plate, is disclosed in US-patent 5,022,171. It is the primary objective of this invention to provide a magnetically operated display unit which presents clear images in the darkness or in bright sunlight. This problem is solved by a magnetically operated display unit according to claim 1. In the drawings: FIG. 1 is a perspective view of a magnetically operated display. FIG. 1 shows a magnetically operated display unit 2 including a frame 4 including a base 6 defining five apertures (not shown). Two ferromagnetic rods 8, two ferromagnetic pins 10 and a light emitting diode (LED) 12 are correspondingly inserted through the apertures defined in the base 6. Each of the ferromagnetic rods 8 includes a lower tip and an upper tip. The LED 12 includes two leads 13. A wire 14 is sequentially wound around the ferromagnetic rods 8 so that a solenoid 16 is formed on each of the ferromagnetic rods 8. The wire 14 includes two ends each soldered to a corresponding one of the ferromagnetic pins 10. The lower tips of the ferromagnetic rods 8 are linked to each other by means of a ferromagnetic strip 17 so that the ferromagnetic rods 8 and the ferromagnetic strip 17 form a U-shaped ferromagnetic element. Each of the ferromagnetic pins 10 can be inserted into a socket (not shown) so that the magnetically operated display unit can be connected with a circuit 18. The LED 12 is also connected with the circuit 18. Two arms 20 project upwardly from the frame 4. Two fingers 21 project upwardly from each of the arms 20. Each of the fingers 21 includes an inner face opposite to the remaining one of the fingers 21. A bulbous portion is formed on the inner face of each of the fingers 21 near a tip thereof thereby defining a narrow entrance to a recess defined between the two fingers. A plate 22 includes a color identical to that of the frame 4. Two axles 24 project from the plate 22 in two opposite directions. Each of the axles 24 is pushed past the tips of the fingers 21 projecting from a corresponding one of the arms 20 so that each of the axles 24 is retained between the fingers 21 projecting from a corresponding one of the arms 20. Thus, the plate 22 is pivotably mounted on the frame 4. A magnet 26 includes a north pole at a tip and a south pole at an opposite tip. The magnet 26 is embedded in the plate 22. The tips of the magnet 26 are located between and in line with the upper tips of the ferromagnetic rods 8. The plate 22 defines a cutout 28 through which the upper tip of one of the ferromagnetic rods 8 and the LED 12 are inserted. A reflector 30 includes a color different from that of the plate 22. The reflector 30 is adhered to the plate 22. The reflector 30 defines a cutout 32 through which the upper tip of one of the ferromagnetic rods 8 and the LED 12 are inserted. The reflector 30 conforms in profile to the plate 22. The circuit 18 includes a first switch SW1, a second switch SW2 and a third switch SW3. The first switch SW1 is connected with an end of the wire 14. The second switch SW2 is connected with the remaining end of the wire 14. The third switch SW3 is connected with the LED 12. Each of the switches SW1 and SW2 can be turned between a ground electrode and a positive electrode. As shown in FIG. 1, the first switch SW1 is turned to the positive electrode and the second switch SW2 is turned to the ground electrode so as to direct a current through the solenoids 16 in a first direction, thus producing a first magnetic field between the upper tips of the ferromagnetic rods 8. Then, both of the switches SW1 and SW2 can be turned to the positive electrode or the ground electrode whilst the first magnetic field remains. The first switch SW1 can be turned to the ground electrode and the second switch SW2 is turned to the positive electrode so as to direct a current through the solenoids 16 in a second direction opposite to the first direction, thus producing a second magnetic field between the upper tips of the ferromagnetic rods 8. The direction of the first magnetic field is opposite to the direction of the second magnetic field. Then, both of the switches SW1 and SW2 can be turned to the positive electrode or the ground electrode whilst the second magnetic field remains. As mentioned above, the first magnetic field or the second magnetic field is produced between the upper tips of the ferromagnetic rods 8, therefore the plate 22 to which the magnet 26 is attached is turned between two opposite positions. The third switch SW3 can be turned on so that LED 12 emits light. The LED 12 includes an upper tip which should be located above the combination of the plate 22 and the reflector 30 so that the LED 12 is clearly visible. The upper tip of the LED 12 should be located below the upper ends of the ferromagnetic rods 8 so that the combination of the plate 22 and the reflector 30 will not be hindered by means of the LED 12 when the combination of the plate 22 and the reflector 30 is pivoted to a position opposite to the position as shown in FIG. 1. The ferromagnetic rods 8 and the ferromagnetic strip 17 can be replaced with a one-piece U-shaped ferromagnetic element (not shown). If the magnetically operated display unit 2 is used in a vehicle (not shown), a transparent panel (not shown) is located in front of the magnetically operated display unit 2. When the vehicle is driven, there will be friction between air and the transparent panel thus resulting in a static charge in the transparent panel. The combination of the plate 22 and the reflector 30 is pivoted when it is in use thus resulting in a static charge in the magnetically operated display unit 2. The static charge produced in the transparent panel and the static charge produced in the magnetically operated display unit 2 will attract each other thus causing difficulty for the pivoting of the combination of the plate 22 and the reflector 30. Thus, the static charge produced in the magnetically operated display unit 2 should be removed. A conductive agent is added in plastic from which the frame 4, the plate 22 and the reflector 30 are made so that frame 4, the plate 22 and the reflector 30 are conductive to a limited extent for releasing the static charge to the leads of the LED 12 for removing the static charge.

Claims: A magnetically operated display unit (2) comprising a frame (4) with a color, a plate (22) pivotably mounted on the frame and including a first surface (30) with a color different to that of the frame (4) and a second surface with a color identical to that of the frame (4) and having a magnet (26) attached thereto, two ferromagnetic rods (8), the tips of the magnet (26) being located between the upper tips of the ferromagnetic rods (8), the ferromagnetic rods having a solenoid for producing a first magnetic field and a second magnetic field having a direction opposite to the direction of the first magnetic field when opposite currents are selectively directed through the solenoid for turning the plate (22) with the attached magnet (26) between two opposite positions to selectively expose to view one surface of the plate (22) and a light source mounted on the frame, characterized in that the light source is a light emitting diode and the plate defines a cutout for receiving the light emitting diode (12) and one of the tips of the ferromagnetic rods (8) such that the tip of the light emitting diode (12) is located on a level above the plate (22) so that the light emitting diode is clearly visible. A magnetically operated display unit (2) according to claim 1 comprising a switch for selectively switching the light emitting diode on and off. A magnetically operated display unit (2) according to claim 1 or 2, wherein two solenoids are mounted each on a corresponding one of the ferromagnetic rods (8) and the solenoids (16) are different portions of a wire. A magnetically operated display unit (2) according to any one of the preceding claims, wherein the tips of the magnet (26) are located between and in line with the upper tips of the ferromagnetic rods (8). A magnetically operated display unit (2) according to any one of the preceding claims, wherein switches provided for selectively directing opposite currents through the solenoid (16) can be switched to a position where no current flows while the magnetic field remains. A magnetically operated display unit (2) according to any one of the preceding claims, wherein the frame (4) includes a base defining two apertures through each of which a corresponding one of the ferromagnetic rods (8) is inserted. A magnetically operated display unit (2) according to any one of the preceding claims including a reflector (30) attached to the first surface of the plate (22), the reflector (30) including a color different to that of the frame. A magnetically operated display unit (2) according to any one of the preceding claims, wherein the frame (4) and the plate (22) are made of plastic added with conductive agent so that the frame (4) and the plate (22) are conductive to a limited extent. A magnetically operated display unit (2) according to any one of the preceding claims including an arm (20) projecting upwardly from the frame (4) and two fingers (21) projecting upwardly from the arm, each of the fingers (21) including an inner face opposite to the remaining one of the fingers (21) and a bulbous portion formed on the inner face thereof near a tip thereof, thereby defining a narrow entrance to a recess defined between the two fingers (21).

Inventors: KAO PIN CHI, KAO, PIN CHI
Applicants: LITE VISION CORP, LITE VISION CORPORATION
Application year: 1995
Main classification: G09F9
IPC codes: G09F9