GB1599606A

GB1599606A - Opto-electronic display

Info

Publication number: GB1599606A
Application number: GB1360978A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-04-06
Filing date: 1978-04-06
Publication date: 1981-10-07

Description

(54) IMPROVEMENTS IN OR RELATING TO OPTO-ELECTRONIC DISPLAY (71) I, EDMOND SUCHET, a French citizen, of 76 Rue du Role, 91800 Brunoy, France, do hereby declare the invention, for which I pray that a patent may be granted to me. and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a device for displaying the time by means of an optoelectronic display system comprising lightemitting diodes. The display system may be a numerical or analog opto-electronic indicating system.

In known devices for displaying information, such as the time, and incorporating opto-electronic display devices, the display device is as a rule, covered only by a thin plate of glass, or transparent plastics, which, when the display system utilises electroluminescent elements, such as light emitting diodes, arranged to emit light of a predetermined colour, is of a corresponding colour.

Thus, where the light emitted by the electroluminescent elements is red or green, the thin plate will also, in general, be red or green respectively. Such a thin plate certainly transmits the light emitted by the electroluminescent elements of the opto-electronic display system, but it also transmits the external sunlight or artificial light to the electroluminescent elements, and this may be troublesome when the ambient light is relatively intense. as in that case all the electroluminescent elements of the opto-electronic display system which are not excited can be seen.

Moreover. when electroluminescent display systems are used in watches, more particularly wrist watches, the plates covering them are not very attractive, more particularly when they are formed by a redtinted glass or plastics watch glass or the like.

It is an object of the invention to provide a device for displaying the time, including an opto-electronic display system comprising light emitting diodes, in which the light emitting diodes, when not energised, are invisible to the eye.

Another object of the invention is to provide a device of the kind specified which performs a decorative function, more particularly on wrist watches.

According to the invention there is provided a device for displaying the time, including an opto-electronic display comprising light-emitting diodes, a transparent precious stone, gemstone or ornamental stone covering said display and having a peripheral edge held in a securing bezel, and, disposed between said display and the surface of said stone which is remote from the display and presented outwardly of said display, a surface which is partly light transmitting and partly light reflecting, so as to transmit a significant proportion of the light falling thereon and to reflect a significant proportion of the light falling thereon, so that when any said light emitting diode in the display is not energised, it is substantially invisible to the eye, whereas when any lightemitting diode of the display is energised that diode is visible to the eye through said transparent stone.

In a preferred embodiment of the invention the surface which reflects the outside light is obtained by depositing, more particularly by evaporation in vacuo, a metallisation layer on the face of said stone which is adjacent and faces towards the display.

The previous, semi-precious or ornamental stone can be natural or completely synthetic, or obtained from powder of natural stone.

The precious, semi-precious decorative stone according to the invention can be cut en cabochon, or be a section of flat, uncut stone or be cut in lens shape, or it can have a faceted cut with a flat or curved (either convex or concave) top part enabling the information displayed by the opto-electronic system to be read. The shape of the stone, particularly as viewed in plan, can be round, oval, shuttle-shaped, heart-shaped, pearshaped, rectangular, square or fancy.

To improve the reading of the optoelectronic system, the side of the stone facing towards the display can be formed with a window whose edges can advantageously be dulled, the dulled surface possibly extending over the whole of the peripheral part of the stone not required for displaying the illuminated information.

The side of the stone facing towards the display can be flat, convex or concave, the shape and cutting of the stone being such that all the rays of light emitted by the optoelectronic system are not reflected, and an optical lens can be interposed between the base of the stone and the opto-electronic system.

The opto-electronic system can be numerical or analog.

The use of a precious, semi-precious or decorative stone means that even when the time display is not energised the device incorporates a jewel of decorative value superior to present day wrist watches with opto-electronic display systems.

A device embodying the invention can be embodied in a wrist watch, a watch mounted in a pendant, a brooch, a ring, etc., and also a watch mounted on any article such as, for instance, a lighter.

The present invention will be better understood from the following description of two non-limitative exemplary embodiments illustrated in the accompanying drawings, wherein: Figure 1 is a plan view of the case of a wrist watch embodying the invention, Figures 2 and 3 are sections, taken along lines IIII and III--III in Figure 1 respectively, and Figure 4 is a sectional view of another embodiment of a device embodying the invention.

The first embodiment of the time display device embodying the invention is shown in Figures 1 to 3, which partially illustrates a casing 1 of an electronic watch, which can be a wrist watch, or a watch mounted in a pendant, brooch, or ring, for instance.

The watch case 1 contains a conventionally disposed opto-electronic time display 2 (not shown in detail), incorporating lightemitting diodes. The opto-electronic display 2 is associated with an electronic circuit (not shown) and supplied from a source such as a battery (not shown).

The opto-electronic display 2 is so disposed in the watch case 1 as to be visible through an aperture 3 with which the top face of the case is formed. The opto-electronic system 2 can be disposed either substantially at the level of the aperture 3 or slightly therebelow.

The top part of the case has encircling the aperture 3 a flange 4 enabling a precious stone 5 to be set in conventional manner above the display 2. However, conventional setting claws can be substituted for the continuous flange 4.

In the embodiment illustrated in Figures 1 to 3, the precious stone 5 is cut en cabochon.

However, the invention is not limited to that cutting. and the precious stone 5 can take any form, more particularly, a decorative fancy form, on condition that it is transparent, so that it transmits the rays of light emitted by the opto-electronic system 2.

Encircling the aperture 3 a seal 6 is disposed between the top face of the watch case 1 and the bottom face of the precious stone 5, the seal 6 preventing any dirt from getting into the watch case 1. The precious stone 5 can be glued to the system 2 or be placed on it with the interposition of a seal cover or it can be at a distance from the system 2.

The bottom of the precious stone 5 is formed with a slight recess 7 with a flat or slightly incurved bottom, the recess 7 having substantially the dimensions of the serviceable part of the display 2 and being shallow, having a depth, for instance, of about 0.5 to 1 mm. The edges of the recess 7 can be dulled, and so can that part of the bottom face of the precious stone 5 which encircles the recess 7.

The dulling has the reference 8; it improves the channelling of the information emitted by the opto-electronic system 2. However, this dulling is not absolutely necessary to the invention.

Preferably a layer 9 which is partly light transmitting and partly light reflecting so that it reflects a significant proportion of the light falling on the stone from the outside but transmits a significant proportion of the light emitted by the opto-electronic system 2, is deposited on the surface of the bottom of the recess 7. Of course, the layer 9 must be so deposited as not to damage the precious stone 5. The method of depositing the layer 9 and its characteristics will be explained herebelow with reference to the embodiment illustrated in Figure 4.

An optical lens (not shown) can be disposed between the opto-electronic display 2 and the precious stone 5, and the shape of the recess 7 can be adapted to the shape of the lens, which enlarges the information displayed by the display 2 to tender it more clearly visible.

However, it is not absolutely necessary to provide the recess 7; since the bottom face of the stone 5 can be completely flat or convex or concave.

If the time is not displayed-i.e. when the display 2 is not energised or illuminated--all that is seen on the top face of the watch case 1 is the precious stone 5, which therefore produces a decorative effect which is impossible with the glass, or plastics watch glasses of the prior art watches.

When the user of the watch having a time display device described with reference to the drawings wants to display the time by pressing a suitable contact (not shown), the time display elements of the display 2 are energised, so that the user can seen the time through the precious stone 5. Of course, although the precious stone 5 can be of any shape. it must not reflect all the rays of light emitted by the display 2. More particularly, in the case of a stone having its main faces incurved, the radii of curvature of the faces will be calculated in known manner as a function of the refractive index of the stone (as a rule of the order of 1.5 to 1.8), so as to avoid complete reflection.

Fig. 4 illustrates a second embodiment of the time display according to the invention.

Fig. 4 also partially shows a watch case 40 containing an opto-electronic display 41 disposed in the same way as the display 2 in the first embodiment.

The casing 40 has claws 42 enabling a fine or decorative precious stone 43 to be set above the display 41; in this second embodiment the precious stone is a flat section but, of course. it can take any other form, as stated hereinbefore with reference to the first embodiment.

Disposed between the precious stone 43 and the opto-electronic display 41 is a watch glass 44 made of glass, having, for instance, a thickness of 0.3 mm and contacting the bottom surface of the precious stone 43, the main surface of the watch glass 44 having substantially the same dimensions as the bottom surface of the stone 43 which it contacts. However, it is not necessary for the watch glass 44 to be in close contact with the precious tone 43. The watch glass 44 can be flat or slightly incurved, or can even be a lens of appropriate shape.

A seal 45 interposed between the bottom face of the watch glass 44 and the top face of the watch case 40. If the watch glass 44 were not in close contact with the bottom face of the precious tone 43, a seal would also be disposed between the watch glass 44 and the precious stone 43, all along the periphery of the precious stone 43, to prevent dust, steam etc. for getting in between the watch glass 44 and the precious stone 43.

The bottom face of the watch glass 44-i.e.

its face turned towards the opto-electronic display 41 comprises a coating 46 which transmits a significant proportion of the light emitted by the display 41, while reflecting a substantial proportion of the light, falling thereon from outside, thus preventing the details (more particularly the non-energised parts) of the opto-electronic system from being rendered visible by light from outside.

However, the coating 46 can be deposited on the top face of the watch glass 44 or on the bottom face of the precious stone 43.

In a preferred embodiment of the invention the layer 46 is a thin layer of metal deposited by evaporation in vacuo.

The layer 46 is deposited in vacuo in known manner. the thickness of the deposit being controlled so as to obtain a predetermined coefficient of transmission and reflection by the layer. As a rule, the time for depositing the layer 46 is a few minutes.

If the display 41 is formed by lightemitting diodes, red ones for instance, a filter transmitting substantially only red light of a wavelength of about 6.500 A can be deposited between the display and the stone, or the body of the watch glass 44 can be coloured, on condition that this does not give the fine or decorative precious stone 43 an undesirable tint.

The display 41 can be either numerical or analog.

WHAT I CLAIM IS: 1. A device for displaying the time, including an opto-electronic display comprising light-emitting diodes, a transparent precious stone, gemstone or ornamental stone covering said display and having a peripheral edge held in a securing bezel, and, disposed between said display and the surface of said stone which is remote from the display and presented outwardly of said display, a surface which is partly light transmitting and partly light reflecting, so as to transmit a significant proportion of the light falling thereon and to reflect a significant proportion of the light falling thereon, so that when any said light emitting diode in the display is not energised, it is substantially invisible to the eye, whereas when any lightemitting diode of the display is energised that diode is visible to the eye through said transparent stone.

2. A device according to claim 1 wherein said surface which is partly light reflecting and partly light transmitting is obtained by deposition of metal on the surface of the stone which faces towards said display.

3. A device according to claim 1 or claim 2 wherein the side of the stone facing said display has a recessed central part of an extent corresponding to that of said display and bounded by a marginal part.

4. A device according to claim 3 wherein said marginal part is dulled.

5. A device according to any preceding claim in which the surface of the stone remote from, and facing away from, said display, is convexly curved.

6. A device according to any preceding claim in which said stone is a synthetic stone.

7. A device according to any one of claims 1 to 5 in which said stone is formed from powder of natural stone.

8. A device for displaying the time, substantially as hereinbefore described with reference to and as shown in Figures 1 to 3 of the accompanying drawings.

9. A device for displaying the time, substantially as hereinbefore described with reference to and as shown in Figure 4 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. through the precious stone 5. Of course, although the precious stone 5 can be of any shape. it must not reflect all the rays of light emitted by the display 2. More particularly, in the case of a stone having its main faces incurved, the radii of curvature of the faces will be calculated in known manner as a function of the refractive index of the stone (as a rule of the order of 1.5 to 1.8), so as to avoid complete reflection. Fig. 4 illustrates a second embodiment of the time display according to the invention. Fig. 4 also partially shows a watch case 40 containing an opto-electronic display 41 disposed in the same way as the display 2 in the first embodiment. The casing 40 has claws 42 enabling a fine or decorative precious stone 43 to be set above the display 41; in this second embodiment the precious stone is a flat section but, of course. it can take any other form, as stated hereinbefore with reference to the first embodiment. Disposed between the precious stone 43 and the opto-electronic display 41 is a watch glass 44 made of glass, having, for instance, a thickness of 0.3 mm and contacting the bottom surface of the precious stone 43, the main surface of the watch glass 44 having substantially the same dimensions as the bottom surface of the stone 43 which it contacts. However, it is not necessary for the watch glass 44 to be in close contact with the precious tone 43. The watch glass 44 can be flat or slightly incurved, or can even be a lens of appropriate shape. A seal 45 interposed between the bottom face of the watch glass 44 and the top face of the watch case 40. If the watch glass 44 were not in close contact with the bottom face of the precious tone 43, a seal would also be disposed between the watch glass 44 and the precious stone 43, all along the periphery of the precious stone 43, to prevent dust, steam etc. for getting in between the watch glass 44 and the precious stone 43. The bottom face of the watch glass 44-i.e. its face turned towards the opto-electronic display 41 comprises a coating 46 which transmits a significant proportion of the light emitted by the display 41, while reflecting a substantial proportion of the light, falling thereon from outside, thus preventing the details (more particularly the non-energised parts) of the opto-electronic system from being rendered visible by light from outside. However, the coating 46 can be deposited on the top face of the watch glass 44 or on the bottom face of the precious stone 43. In a preferred embodiment of the invention the layer 46 is a thin layer of metal deposited by evaporation in vacuo. The layer 46 is deposited in vacuo in known manner. the thickness of the deposit being controlled so as to obtain a predetermined coefficient of transmission and reflection by the layer. As a rule, the time for depositing the layer 46 is a few minutes. If the display 41 is formed by lightemitting diodes, red ones for instance, a filter transmitting substantially only red light of a wavelength of about 6.500 A can be deposited between the display and the stone, or the body of the watch glass 44 can be coloured, on condition that this does not give the fine or decorative precious stone 43 an undesirable tint. The display 41 can be either numerical or analog. WHAT I CLAIM IS:

1. A device for displaying the time, including an opto-electronic display comprising light-emitting diodes, a transparent precious stone, gemstone or ornamental stone covering said display and having a peripheral edge held in a securing bezel, and, disposed between said display and the surface of said stone which is remote from the display and presented outwardly of said display, a surface which is partly light transmitting and partly light reflecting, so as to transmit a significant proportion of the light falling thereon and to reflect a significant proportion of the light falling thereon, so that when any said light emitting diode in the display is not energised, it is substantially invisible to the eye, whereas when any lightemitting diode of the display is energised that diode is visible to the eye through said transparent stone.

4. A device according to claim 3 wherein said marginal part is dulled.