NL2002483C2

NL2002483C2 - Display device and watch.

Info

Publication number: NL2002483C2
Application number: NL2002483A
Authority: NL
Inventors: Josephus Petrus Maria Crooymans
Original assignee: Vluttersven Beheer B V
Priority date: 2009-02-03
Filing date: 2009-02-03
Publication date: 2010-08-04

Description

DISPLAY DEVICE AND WATCH FIELD OF THE INVENTION

5 The invention relates to a display device comprising a compartment having a transparent display surface and a base surface opposite the display surface, the compartment containing multiple particles.

The invention also relates to a watch.

10

BACKGROUND OF THE INVENTION

European patent application EP1542067 discloses a pixelated image display device.

In the display device, two opposing substrates, one of which is transparent, and 15 partition walls together form a plurality of spaces. Two or more groups of chargeable particles are arranged in the plurality of spaces. By applying a voltage to electrodes arranged in each one of the spaces the particles may be moved to or from the transparent substrate. Whether the particles are close to the transparent substrate or not is visible from outside the display device. In this way, each space can be put in 20 one of two visibly different states. The plurality of spaces is thus configured as a plurality of pixels. An image may be formed on the display device by putting some of the plurality pixels in one state and some of them in another. A light emits light onto an image display surface of the image display.

25 SUMMARY OF THE INVENTION

It is a problem of the known display device that the manufacture of the partition walls requires costly precision engineering.

30 It is an object to provide a particle based display device avoiding the need to manufacture partition walls.

This and other objects are achieved by the display device according to the invention. The display device comprises: a compartment having a transparent display surface 35 and a base surface opposite the display surface, the compartment containing multiple 2 particles; and at least one pole operative for being a source of a force field, which permeates at least part of the compartment, the force attracting or repelling at least one of the multiple particles. The display device is configured to move relative to the display surface at least part of the multiple particles under influence of the force field 5 to a selectable one of multiple locations in the compartment, thereby forming an image visible through the display surface.

Since the pole can move the particles to multiple places, the particles can be arranged to form an image. The resolution of the display device need not be very high, for 10 example, a hundred or even fewer particles suffice to build simple images and time representations. As the particles are arranged in one compartment, there is no need to use separation walls in the compartment since the at least one pole is arranged to move the particles to more than one place. In this way, pixelation is not necessary.

15 In a preferred embodiment, the display device comprises multiple poles. The display device is configured to select the selectable one of multiple locations by selecting and controllably operating at least one of the multiple poles.

Having multiple poles allows moving the particles to multiple selectable places, by 20 selecting the corresponding pole. By arranging the poles in a grid, a pixelated display device can be achieved, or approximated, if so desired. Note that a number of poles arranged in a grid can be combined with one or more poles arranged in other ways, e.g., in a fixed or moving configuration.

25 On the pixelated display any suitable image may be shown, for example, a logo, a word, a digital or analog representation of time, a symbol, etc.

In a preferred embodiment, the display device comprises an actuator for moving the pole, wherein the display device is configured to select the selectable one of multiple 30 locations by moving the pole relative to the display surface. Preferably, the pole is moved substantially parallel to the base surface.

A problem of the known display device based on moving particles is that they typically are not well-suited to displaying moving images. The reason is that in a pixelated 35 display device using separation walls, an image moves by setting and resetting many 3 pixels. As it takes some time for a particle to move to and from the display side, the known display device has a limited refresh rate. Due to the limited refresh rate the known display device is not suitable for displaying moving images. This problem is avoided by using an actuator to move the poles themselves. In this way, a pixel may 5 follow the pole in continuous manner. The particles do not need to move back and forth to the display side, rather the particles are moved directly parallel to the display side.

Moreover, using an actuator has the advantage that a moving and meaningful image 10 can be displayed using only relatively few poles. For example, by taking the poles to be the hands of a watch, an updateable representation of time can be displayed using only two poles. The number of poles and/or hands can be chosen, as one, two, three, or any desired number, representing, e.g., an hour-hand, a minute-hand ora seconds-hand, etc.

15

In a preferred embodiment, at least one of the multiple poles is formed in a particular shape and the display device is operative to form a particular predetermined image in dependency on the particular shape. For example, a logo or other shape can be displayed using a corresponding pole. It is noted that a display device could be made 20 having exactly one pole shaped in this manner. Preferably, the shaped pole is combined with other shaped poles, a grid of poles, and/or moving poles.

The predetermined image can have any suitable appearance. For example, the particular image may be logo, such as a corporate logo or brand, a word, a symbol, 25 such as a peace symbol, etc.

In a preferred embodiment, in the compartment a guiding means is formed for guiding one or more of the multiple particles across the compartment. When it is desired to control the path of the particles in some manner, these guides may be used. A guide 30 can be formed by shaping the base surface. A guide may also be formed by, e.g., configuring a wire-framework in the compartment for guiding particles. Guides have the advantage that the position of the particles is better controlled. Especially, in applications, such as timepieces, this can be desirable. Multiple guides may be used to control multiple particles. In one guide, there may be any number of particles, for 35 example, only one particle, or a plurality of particles.

4

In a preferred embodiment, the guiding means is formed at the base surface and/or display surface. Shaping the form of the base surface and/or display surface is an effective way to arrange the guides, without the need of introducing a new structure 5 into the compartment.

A further advantage of using a compartment as in the invention, is that particles need not have a uniform size.

10 In a preferred embodiment of the display device according to the invention, a timepiece is configured for controlling a selection in the multiple locations to form an image representing a current time. The display device can be applied advantageously in a watch.

15

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in further detail by way of example and with reference to the accompanying drawings, wherein: 20

Figure 1 is a block diagram illustrating a cross section of a first embodiment of the display device according to the invention,

Figure 2 is a block diagram illustrating the use of an electrical insulator,

Figure 3 is a block diagram illustrating a top view of a second embodiment of a display 25 system according to the invention,

Figure 4 is a block diagram illustrating a cross section of the second embodiment, Figure 5 is a block diagram illustrating a top view of a third embodiment of a display system according to the invention,

Figure 6a and 6b are block diagrams illustrating a top view of a fourth embodiment of 30 a display system according to the invention.

Throughout the Figures, similar or corresponding features are indicated by same reference numerals.

5

List of Reference Numerals: 100 a display device 102,104 a pole 106 multiple particles 110 a base surface 112 a connection 140 a controller 150 a voltage source 210 an electrical insulator 300 a display system 312 a ball 322 a first guide 324 a second guide 500 a watch 502 a hand 504 an indicator 602 a positive image 604 a negative image

DETAILED EMBODIMENTS

While this invention is susceptible of embodiment in many different forms, there is 5 shown in the drawings and will herein be described in detail one or more specific embodiments, with the understanding that the present disclosure is to be considered as exemplary of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described.

10 Figure 1 illustrates in a block diagram a cross section of a display device 100, a first embodiment of the invention.

Display device 100 comprises a base surface 110. On top of base surface 110 there are arranged multiple particles 106. Opposite base surface 110 a display side (not 15 shown) is configured which is connected to base surface 110 with, e.g., walls (not shown). The display side, base surface 110 and the walls together form a compartment (not shown) in which multiple particles 106 are comprised. Preferably, 6 the compartment prevents multiple particles 106 from escaping display device 100. The display side is at least partially transparent, in order to allow multiple particles 106 to be visible from the outside. The display side may be implemented as fully transparent, but may also be, fully or partially, opaque or translucent. The display side 5 can be made from any suitable material, including, e.g., glass, plastic, etc. The display side may comprise a display of another type, e.g., an LCD display.

In a preferred embodiment, display device 100 comprises exactly one compartment. However, also multiple compartments may be combined to advantage in a display 10 device, for example two or more compartments, possibly in some arrangement, such as a grid. Each one of the multiple compartments has a transparent display surface and a base surface opposite the display surface. The multiple compartments may share a common display surface and base surface. At least two of the multiple compartments preferably contain multiple particles. At least one pole, preferably 15 multiple poles, are operative for being a source of a force field, which permeates the compartments, the force attracting or repelling at least one of the multiple particles. The display device is configured to move relative to the display surface at least part of the multiple particles comprised in a specific one of the multiple compartments, under influence of the force field to a selectable one of multiple locations in the specific 20 compartment, thereby forming an image visible through the display surface of the specific compartment. Preferably, the multiple particles in the specific compartment can be moved independent from the multiple particles in other ones of the multiple compartments. The latter may, e.g., be achieved using multiple poles, each specific one of the multiple compartments being operated on by a specific one of the multiple 25 poles.

Display device 100 comprises at least one pole. In Figure 1, 6 poles are shown, some of which are indicated with reference numerals 102 and 104. The number of 6 poles is arbitrary, and can both be larger and smaller. A pole can be operated to produce a 30 force field. The force field permeates at least part of the compartment. Multiple particles 106 are sensitive to this force. The configuration of the compartment allows multiple particles 106 to move, at least, parallel to base surface 110. In an embodiment the movement of multiple particles 106 can be restricted to substantially only contain a component parallel to base surface 110. The force may be an attracting 35 or a repelling force. In Figure 1, two of the six poles are shown in their active, 7 operative, position. The active poles are indicated with numeral 104, and are shown in black. In figure 1, four of the six poles are shown in their non-active, dormant, position. The dormant poles are shown in white, and one of them is indicated with numeral 102. In Figure 1, the force is an attractive force. Note that multiple particles 106 are 5 attracted to poles 104. Note that if none of the poles are active, that is, all of them are dormant, then multiple particles 106 would be distributed randomly across the compartment. In an embodiment, the multiple particles remain visible at all times. In another embodiment, part or all of the multiple particles may be obstructed from view by an opaque portion in the display side.

10

Preferably, the poles may be embedded in base surface 110. However, the poles can also be embedded in the display side or in the walls. If the poles are embedded in the display side, then preferably transparent poles are used.

15 Various means can be used to produce a force field using a pole. For example, the force field may comprise a magnetic force field. This can be accomplished, e.g., by configuring the poles with a coil, i.e., an electromagnet, and using particles which are sensitive to magnetic forces, e.g., particles comprising or consisting of, iron, or other suitable metals.

20 A preferred way to create the force field is to use electrostatic forces, also known as Coulomb’s forces. In such an embodiment, the poles are connected to a voltage source 150, and multiple particles 106 are positively or negatively charged. If the polarity of the poles and the polarity of multiple particles 106 agree then the particles 25 feel an opposing force, if the polarities are opposite then the particles will feel an attracting force.

Preferably, when using static forces an electrical insulator 210 is arranged to spatially separate the poles from multiple particles 106. Electrical insulator 210 avoids that 30 multiple particles 106 discharge when they come into contact with poles 104. Figure 2 shows the electrical insulator 210 and how it can be arranged. For example, in Figure 2, electrical insulator 210 is arranged on top of base surface 110 also opposite the display side. In this way, the poles are separated from multiple particles 106. Alternatively, instead of one large insulator, also multiple smaller insulators can be 35 used, e.g., one for each pole.

8

Multiple particles 106 can be made of various materials. One advantageous choice for multiple particles 106 sensitive to electrostatic forces comprises silicon powder. Other choices for the material of multiple particles 106 include, glass, sand, precious stones, 5 etc. The shape of multiple particles 106 can vary. For example, multiple particles 106 can be spherical, cubical, have any irregular shape, etc. Also, multiple particles 106 may be of various different sizes. Base surface 110 may be of various suitable materials. If static forces are used, then the compartment, including base surface 110, the display side and the walls are preferably electrically insulating. They may be made 10 of plastic, etc. It is important that multiple particles 106 are, at least some-what charged, for them to be attracted by electrostatic force. It has turned out that in practice, that for some materials the multiple particles are charged, at least to some extent, by ordinary air contact. This small charge is sufficient for some applications. However, other known methods can be applied to charge the particles, if such is 15 desired. For example, particle charge methods are known from toner chargers in copier machines and laser printers. Similarly, those fields also provide other ways to charge poles.

In Figure 1, the poles are connected to control connections 112. Connection 112 20 connects the poles 102 and 104 with a controller 140. Controller 140 is, e.g., an electronic device and selects which one or ones of the poles will be connected to voltage source 150. In case magnetic forces are used, then controller 140 selects which one of the electromagnets will be operated. In this way, controller 140 acts as a router, connecting some of the poles with voltage source 150 25

When display device 100 is not used to display an image all of the poles may be dormant. In that situation no force field need be present. In the absence of a force field, multiple particles 106 will be distributed randomly across the compartment (not shown). However, it may also be the case, that some charge may be left on some of 30 the poles and that a remnant of a previous image remains visible, at least for some time. A user can indicate to display device 100 his desire to see an image in various ways. For example, the user may press a button, or he may tap the device, etc. In one embodiment the display device is activated by a motion sensor, for example, by briefly shaking display device 100.

35 9

After activation, controller 140 determines what image to display and selects the poles to activate. For example, controller 140 comprises a microprocessor executing a computer program stored in a memory. The activated poles generate a force field which affects multiple particles 106. In case the force is attractive, the particles will 5 accumulate around the operative poles. In this way, an image is formed by the particles, which is visible through the display side. Preferably, the poles are arranged in a regular pattern, to simplify the forming of images. For example, the multiple poles may be arranged in a grid, which extends parallel to the display surface. Different possibilities exist for the grid, e.g., rectangular, hexagonal, etc.

10

After the image is formed it may remain visible for a limited amount of time, or indefinitely. In case electromagnetic forces are used, the image power may be cut after some time, e.g., after a predetermined amount of time, say after 5 seconds. This will spare an energy source of display device 100. In case electrostatic forces are 15 used, it may be that the force field persists for some time and slowly disappears, for example, through dissipation of the charge on the poles. When permanent magnets are used to create an image then the image will typically remain, unless the magnets are physically moved away from the compartment.

20 Figure 3 illustrates in a top view, display device 300 which is a refinement of the embodiment shown in Figure 1. Figure 4 shows a cross section of display device 300.

In Figure 3, two of the multiple particles 106 are visible through the display side: spheres 312. Base surface 110 comprises two guides for guiding one or more of the 25 multiple particles 106: first guide 322 and second guide 324. The guides may also be applied to the display surface. In Figure 3 two of such guides are shown. The guides are formed by shaping the surface of base surface 110 into two circular approximately half-tubes. It is also possible to use one or more than two guides. In each guide one particle is shown. The two particles shown are spherical. It is possible to use a single 30 guide or more than two guides. Also in one guide more than one particle may be used. When a static force is used, then preferably electrical insulator 210 is used. For example, electrical insulator 210 may be shaped in groves to form one or more guides. Electrical insulator 210 may also be embedded in or below base surface 110. Also base surface 110 can itself be electrically insulating.

35 10

The particles in display device 300 can be moved in the same way as explained for Figure 1. For example, in base surface 110 a relatively small number of poles may be placed, e.g., 12 poles for each guide, regularly spaced around the guide, corresponding to the hours of a clock-dial. However, they may also be moved using a 5 moving pole, as is explained below.

Display device 300 is well suited to display information, especially information that can be visualized as a continuum. In Figure 3, the two particles represent the hands of a clock. Note that on the surface of base surface 110 a dial can be represented, e.g., 10 the hours of the clock. For example, indicators can be printed on base-surface, or on the display side. For example, the sphere 312 in first guide 322 may represent a minute hand and the sphere 312 in second guide 324 may represent an hour guide.

The guides may be configured thus that a particle trapped inside the guide cannot get 15 out the guide. However the guides may also be made shallow. In the latter case, the particles may in principle wander randomly over the compartment, but following the path indicated by the guides, e.g., as needed for display of time, is made more likely.

Figure 5 shows a top view of watch 500, which is another refinement of display device 20 100. In Figure 5 an otherwise known timepiece with two hands is placed in or under base surface 110. The hands of the timepiece are connected to controller 140 and, through controller 140 with voltage source 150. The hands of the timepiece thus act as poles. These poles are moved by the timepiece, which thus acts as an actuator. Note that as the hands progress, the image which is formed on watch 500 differs. In 25 this case, the image formed is of the hands of a timepiece. The hands are indicated with reference numeral 502.

Also shown in Figure 5, are hands 502. The indicators give a visual aid to the user to read the timepiece. In Figure 5, indicators are shown for 3, 6, 9, and 12 o’ clock.

30 Indicators 504 can be made by arranging a fixed pole, e.g., in base surface 110.

Note that an indicator could also be made using multiple poles arranged in a grid.

A display device comprising a moving pole may also be used in novelty items, to show 35 animation, in speedometers, etc. In figure 5 the display device has a round 11 circumference. It is noted however that the particular design of the display device is immaterial. For example, the display device may be formed in a square, octagonal, irregular, etc, shape.

5

Figure 6a and Figure 6b illustrate a top view of an embodiment of the display system, which is a further refinement of display device 100. In these embodiments a pole has a particular shape. In Figure 6a, said shaped pole is activated to attract particles. Accordingly, a positive image 602 is formed in dependency on the shape of the pole.

10 Similarly, in Figure 6b, an opposing force is used. Accordingly, a negative image 604 is formed, being a negative of the shape of the pole. Note that a negative of an image can also be arranged by shaping the pole as the negative of the image, and using an attracting force.

15 It is noted that the display device according to the invention is well suited for use in stylish wearable electronics, in particular in watches. The display device can be used in a watch to display an image representing time. For example, a traditional image, using two or three hand can be used, or a modern digital indication of time, etc.

20 Note that the compartment can obtain other objects than particles as is desirable. For example, a relief may be present as indicators for the hours in a clock. Other objects may include pins, pyramids, models, etc. During operation, as the particles move under the influence of the force, these other objects may obstruct the path of the particles. This has the advantage that the force field is made better visible, as the 25 particles take longer to settle. Moreover, this has the advantage of randomizing the path of the particles, which avoids unwanted lumping of the particles. This can, e.g., be combined with a moving pole.

The following embodiments are considered advantageous: 30 1. A display device (100) comprising: a compartment having a transparent display surface and a base surface (110) opposite the display surface, the compartment containing multiple particles (106); and at least one pole (102,104) operative for being a source of a force field, which permeates at least part of the compartment, the force attracting or repelling at least 35 one of the multiple particles; 12 wherein the display device is configured to move relative to the display surface at least part of the multiple particles under influence of the force field to a selectable one of multiple locations in the compartment, thereby forming an image visible through the display surface.

5 2. A display device as in embodiment 1 wherein the force field comprises an electrostatic force field and the multiple particles are positively or negatively charged.

3. A display device as in embodiment 2 comprising an electrical insulator (210) spatially separating the at least one pole from the multiple particles.

4. A display device as in any one of the preceding embodiments, wherein the force 10 field comprises a magnetic force field.

5. A display device as in any one of the preceding embodiments comprising multiple poles, the display device being configured to select the selectable one of multiple locations by selecting and controllably operating at least one of the multiple poles.

6. A display device as in embodiment 5, wherein the multiple poles are arranged in a 15 grid, which extends parallel to the display surface.

7. A display device as in any one of the preceding embodiments, comprising an actuator for moving the pole, wherein the display device is configured to select the selectable one of multiple locations by moving the pole relative to the display surface.

8. A display device as in embodiment 5, wherein at least one of the multiple poles is 20 formed in a particular shape and the display device is operative to form a particular predetermined image in dependency on the particular shape.

9. A display device as in any one of the preceding embodiments, wherein in the compartment a guiding means is formed for guiding one or more of the multiple particles across the compartment.

25 10. A display device as in embodiment 9, wherein the guiding means is formed at the base surface and/or display surface.

11. A display device as in any one of the preceding embodiments, comprising exactly one compartment.

12. A display device as in any one of the preceding embodiments, wherein the 30 multiple particles are not of a uniform size.

13. A display device as in any one of the preceding embodiments comprising a timepiece configured for controlling a selection in the multiple locations to form an image representing a current time.

14. A display device as in embodiment 13 embodied as a watch.

13 15. A display device as in any one of the preceding embodiments, wherein the compartment comprises obstructions for obstructing a path of the at least one particle when moved under the influence of the force field.

Claims

A display (100) comprising a compartment with a transparent display surface and a ground surface (110) opposite the display surface, the compartment contains a plurality of particles (106); and at least one pole (102, 104) operating as a source of a force field, which penetrates into at least a portion of the compartment, draws or repels the force at least one of the plurality of particles; 10 wherein: the display is configured to move at least one of the plurality of particles relative to the display surface under the influence of the force field to a selected location from a plurality of locations in the compartment, thereby forming an image visible through the display surface.

A display as in Claim 1 wherein the force field comprises an electrostatic force field and the plurality of particles are positively or negatively charged.

A display as in Claim 2 comprising an electrical insulator (210) spatially separating the at least one pole from the plurality of particles.

A display as in any preceding claim, wherein the force field comprises a magnetic force field. 25

A display as in any of the preceding claims comprising a plurality of poles, the display being configured to select the selected location from the plurality of locations by selecting and controlling at least one of the plurality of poles. 30

A display as in Claim 5, wherein the multiple poles are arranged in a grid extending parallel to the display surface.

A display as claimed in any one of the preceding claims, comprising an actuator 35 for moving the pole, wherein the display is configured to select the selected location from the multiple locations by moving the pole relative to the display surface. to move.

A display as in Claim 5, wherein at least one of the plurality of poles is formed in a certain shape, and the screen is operable to display a certain image in dependence on the determined shape.

9. A display screen as in any one of the preceding claims, wherein a guideway is formed in the compartment for guiding one or more of the plurality of particles through the compartment.

A display as in Claim 9, wherein the track is formed on the ground surface and / or the display surface.

A display as in any preceding claim that includes exactly a compartment.

12. A display as in any preceding claim, wherein the plurality of particles are not of a uniform size.

A display as in any preceding claim that includes a timepiece configured to check a selection from the plurality of locations to form an image displaying the current time. 25

A display as in Claim 13 embodied as a watch.

15. A display as in any preceding claim, wherein the compartment includes obstacles for obstructing a path of the at least one particle when it is moving under the influence of the force field.