Title of Invention	ELECTROMECHANICAL DISPLAY ELEMENT FOR INFORMATION DISPLAY SYSTEMS
Abstract	An information display element in the form of a cyclinder painted with two contrasting colors rotates about its axis.it is mounted with its axis parallel to the plane of display system.A motor is empolyed to totate the display element in any of the two directions. An electornic control system by supplying appropriate power signals to motot,positions the display element at any angular position.

Full Text

Field of invention This invention relates to an electromechanical display element for information display systems. The display element which when arranged in large numbers in a matrix and appropriately controlled by electronic circuits, forms information display system. Background of invention A variety of display elements have been invented to meet the needs of information display and ornamental display. These include mechanical, electromechanical & electronic devices. Most of these display elements are designed to be used in plurality of rows and columns to form a display system. Present invention fells under the category of electromechanical display devices used in plurality to form display system. Any electromechanical display element will have: (1) 'Display member', which is the visible part of the display element from the intended viewing distance and (2) An electromechanical drive mechanism to move the display member from one display state to the other. Present invention relates to an improvement in (1) mentioned above. That is, an improvement in the display member, which leads to saving in the cost of production and the display system, becomes more ornamental. Most of the electromechanical information display elements invented in the past have been binary in nature. That is, the element can attain one of the two possible display states. The two display states would be designed to give contrasting looks. The information display is achieved through a combination of elements driven to one state of display & the rest of the elements driven to another state. By using large number of display elements, each of which will be very small compared to the total display area, optical illusion is produced and hence required performance of information display is achieved. The drawback of this method of display using binary elements, is more number of display elements is needed to be used per unit viewing angle, which makes the cost of production of display system, high. US patent No. 5045767 is another case of prior art which is not binary in nature, but the display element has four surfaces and is intended to direct one of those four surfaces to the front of the display system. The person viewing the display system will see that surface fully. The demerit of prior art invention (US patent no.5045767) as compared to the present invention is discussed in the following paragraph. The comparison is in regard to the 'display member' of both the inventions. The present invention addresses only the display member and not the electromechanical drive mechanism. Hence drive mechanisms are not compared. The display member of the said US patent is intended to be positioned at only four angular positions. But, it may be adapted for positioning at any angle from 0 degree to 360 degrees. In case it is placed at any other angular position (than the intended positions), the viewing display area will be different from that in the intended positions. That is, in case the display element is adapted for positioning at any angle, the display member cannot give uniform display area throughout the angular range of 0 degree to 360 degrees. The visible gap between two consecutive display elements depends on the positions attained by the two display elements. This is a demerit of the prior art invention, if it is adapted for application similar to the present invention. The advantage of the present invention as compared to the said US patent is: The display member is intended to be positioned at any desirable angular position (from 0 degree to 360 degrees). The visible area of the display member is same at any angular position. The visible gap between the two consecutive display elements is same irrespective of the positions attained by the concerned elements. This gives better looks to the display system. The movement of display member in the present invention, from one state of display to another state, looks smooth. This is because the display member is always in a valid display state. That is, any position of display member in between start and end positions is also a valid position. This aspect of display element makes it most suitable for ornamental display systems, where the transition from one display pattern to another, gives Psychedelic effect. No other invention in the past gives similar performance as far as this aspect is concerned. Accordingly, it is an object of the present invention, to provide a display element, which considerably reduces the cost of forming the display system. A fiirther object of the invention, is to provide a display element whose design improves the ornamental looks generated by dynamics of display and the movement of display member from one state of display to another state, looks smooth. This invention thus provides an electromechanical display element for information display system, comprising (i) a display member having a cylindrical structure, whose axis is parallel to the plane of the display system, the cylindrical structure being divided into two curved halves which are painted with two contrasting colors diametrically opposite; (ii) an electromechanical drive mechanism to move the display member from one display state to the other, the said mechanism being capable of rotating about its axis in any of the two directions, i.e. clockwise or counter clockwise and capable of being positioned at any angular position; and (iii) a mechanical support to hold the drive mechanism with the background plane of the display system. In one embodiment of the invention the said cylindrical structure, instead of being painted, is mounted with ornamental material giving ornamental looks to the display element. In yet another embodiment, the base of the cylindrical structure is polygonal in shape rather than circular shape. Disclosure of the invention Display element is a cylindrical stracture capable of rotating about its axis and is mounted on a stepper motor driven by a position control system. The axis of cylindrical structure is parallel to the plane of display system & about half of the curved surface will be visible to the viewer of the display system. The cylindrical display element, on its outer surface, is painted with two contrasting colors. Half of the cylindrical surface, along its circumference is painted with one color and the rest with other color. The motor can rotate in any of the two directions depending on the power signals it gets. The cylindrical structure rotates in either clockwise or counter clockwise direction depending on the direction of rotation of motor. In other words, direction of rotation of said cylindrical display element depends on the power signals supplied to the motor. The motor & hence the cylindrical display element is positioned by an electronic circuitry which controls all the elements in the display system. The curved cylindrical surface looks like a plane surface from the intended viewing distance because of the optical illusion, since the size of the display element will be much smaller than the size of entire display system. In another embodiment of the display element, instead of cylinder of circular base, cylinder of hexagonal or octagonal base is used. This does not impair the performance of the display element significantly. A plurality of above-mentioned display elements placed in large number of rows and columns forms a display system capable of displaying alphanumeric information, symbols and other patterns of interest. There are many options of implementing the display element. Using 'four steps per rotation' stepper motor, to drive the cylindrical element is the best mode of implementing. Other options include usage of (1) Servo motor/mechanism to implement the position control system and hence the said display element (2) Stepper motor with more than four steps per rotation, along with an angular position sensor to detect the reference position. The stepper motor employed has only four steps of 90 degrees each. The motor has two pairs of coils, which can be energized independently of each other from the electronic circuitry. A pair of coils is two coils capable of generating opposite magnetic fields to each other. Hence only one coil in a pair is energized at any point in time. The rotor can get settled in only one stable position when any one of the four coils is energized. Micro-stepping techniques are used to get the display element positioned at more than four normal positions of the stepper motor. Number of display elements of present invention needed is much less than that of display elements of binary nature, for the similar performance of the display system. This feet is better illustrated in the drawings. This invention will now be described with reference to the accompanying drawings wherein: Fig 1. shows the mechanical arrangement of the display element; Fig 2. is the schematic representation of the cylindrical structure of the display element; Fig 3. is a schematic drawing of the prior art display system using binary display element; Fig 4. is a schematic drawing of the display system using the display element of the present invention; Fig 5. shows the comparison of the prior art display system and the display system of the present invention; Fig 6. shows the schematic representation of the power circuit of the stepper motor; and Fig 7. shows cases of different positions of a display element for different coil excitations. Figure 1 shows the mechanical arrangement of display element. Top & side views are given. 1 is the back planar support of the display system, on which, the display elements are mounted in several rows and columns. 2 is the set of fasteners holding display element with the back plane. 3 is the mechanical support holding the motor to the back plane. 4 is the cylindrical structure mounted on the motor shaft 6 which can rotate with the said motor shaft and 5 is the stepper motor fastened to the support 3 with the help of fastener set 7. 8 shows the direction of viewing of the display element. Figure 2 is the schematic representation of the cylindrical structure of the display element. The front view is identified by reference numeral 9 where 10 is the axis of the cylinder in the said front view. The top view of the cylinder is identified by reference numeral 11. The point 12, is the axis of the cylinder in top view. Half of the curved surface of the cylinder is painted black & the rest white. 13 shows the portion of cylinder painted black. Figure 2 represents a position of the element wherein only a small portion of the display element on the left side of the viewer is black. The cylinder can be rotated about its axis by the motor. It is important to mention that from the intended viewing distance the cylinder looks like a rectangle which is part black and part white. Figure 3 is a schematic drawing of display system in accordance with prior art of using binary display elements. The display system is shown to be displaying the letter 'A*. There are 9 rows and 9 columns of display elements. Each one of them is shown to take one of two positions, black or white. 14 is an element assuming the position white & 15 is an element assuming the position black. Figure 4 is a schematic drawing of display system in accordance with present invention of display element. The display system is shown to be displaying the letter 'A'. There are 9 rows and 4 columns of display elements. Each of the display elements shown in this figure is painted black and white on the halves of curved surface. 16 is an element which is positioned in such a way mat only white color is seen, and the black colored half of the element is intended to be at the backside of the element. 17 is an element which is positioned to show black on the left side & white on the right side of the viewer to the appropriate angle. 18 is an element which is positioned to show white on the left side & black on the right side of the viewer to the appropriate angle. 19 is an element, which is positioned in such a way that only black color is seen, and the white colored half of the element is intended to be at the backside of the element. Figures 3 and 4 are only for the purpose of illustration and details of shape of display element and the gaps between the elements are not considered. Figures 3 and 4 illustrate that the number of display elements needed to implement the display system using the present invention is less than half of that using prior art inventions of binary display elements. Additionally, present invention uses stepper motor drive. Since, the world technological and commercial situation is such that, stepper motors are available at very low prices, present invention is very novel in cost saving. figure 3 gives tne comparison ot display system in accordance with prior art and the one with the present invention. Figures 3 and 4 have been compressed and placed next to each other and same size of display is maintained for easy comparison. 20 is the display with prior art and 21 is the display system with present invention. Figure 6 shows the schematic representation of power circuit driving the four-position stepper motor. A, B, C and D are the four coils of the motor. A & B are magnetically coupled and produce magnetic fields opposite to each other. A & B are never energized simultaneously at any point in time. C & D are magnetically coupled and produce magnetic fields opposite to each other. C & D are never energized simultaneously at any point in time. 22, 23, 24 and 25 are the electronic switches controlling the power supply to coils A, B, C and D respectively. 26 is the direct current (DC) power supply. Figure 7 shows cases of different positions of a display element for different coil excitations. Only front view of element is shown for each case. Coil numbers mentioned here are in conjunction with the figure 6. The correlation between the coil numbers and positions is just for an illustration. 27 is the position of element with only coil 'A excited. Write portion cylindrical surface is completely visible & black portion is completely at the back. 28 is the position of element with coils 'A' and 'C' excited equally. The cylinder has rotated by 45 degrees compared to 27 to the right, making a small portion of the black color visible at the left side of the viewer. 29 is the position of element with only coil 'C excited. White portion of cylindrical surface is on the right side & black on the left side. Half of the element on the left is black colored. 30 is the position of element with only coil 'B' excited. Black portion of cylindrical surface is completely visible & white portion is completely at the back. 31 is the position of element with only coil 'D' excited. Black portion of cylindrical surface is on the right side & White on the left side. Half of the element on the right is black colored. When a combination of coils is excited, by controlling the ratio of power supplied to two coils, the display element can be positioned at any angle in between the positions attained by element when those two coils are excited independently. For example by controlling the ratio of excitation among the coils A & C, the element can be positioned anywhere between 0 degree and 90 degrees. This illustration demonstrates that by exciting coil combinations A, A-C, C, C-B, B, B-D, D and D-A with appropriate proportions of power, the cylindrical element can be placed at any angular position from 0 to 360 degrees. We claim 1) An electromechanical display element for information display system, comprising: (i) a display member having a cylindrical structure, whose axis is parallel to the plane of the display system, the outer surface of the cylindrical structure being divided into two curved halves which are painted with two contrasting colors diametrically opposite to each other (ii) an electromechanical drive mechanism to move the display member from one display state to the other, the said mechanism being capable of rotating about its axis in any of the two directions, i.e. clockwise or counter clockwise and capable of being positioned at any angular position; and (iii) a mechanical support to hold the drive mechanism with the background plane of the display system. 2. A display element according to claim 1, wherein the said cylindrical structure, instead of being painted, is mounted with an ornamental material for giving ornamental look to the display element. 3. A display element according to claim 1 or 2, wherein the electromechanical drive mechanism is a stepper motor with more than four steps per rotation, along with an angular position sensor to detect the reference position. 4. A display element according to claim 1 or 2, wherein the electromechanical drive mechanism is a servo motor/mechanism to implement the position control system and hence the said display element. 5. A display element according to any one of claims 1 to 4, wherein the said cylindrical structure has a polygonal base instead of circular base, said polygon having six or more number of sides. 6. An electromechanical display element for information display system substantially as hereinbefore described and illustrated in the accompanying drawings.

Documents:

99-mas-2002-claims.pdf

99-mas-2002-correspondence others.pdf

99-mas-2002-correspondence po.pdf

99-mas-2002-description complete.pdf

99-mas-2002-drawings.pdf

99-mas-2002-form 1.pdf

99-mas-2002-form 19.pdf

99-mas-2002-form 26.pdf