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VISUAL DISPLAY SYSTEM WITH TRIANGULAR CELLS
This application relates to visual display units for 5 producing aesthetically pleasing abstract lighting effects and to their associated control systems.
BACKGROUND OF THE INVENTION
The abstract play of light and color has always been 10 fascinating, and over the last century a variety of optical, mechanical, electrical, and electronic devices have been disclosed to produce such effects automatically; in response to an audio input; or under the control of an operator. 15
At the turn of the century, complex effects could only be produced by optical means and "lumia" devices relied on the use of light-varying means such as filters and distorted reflective surfaces as the primary method of producing such effects. 20
Early non-mechanical systems such as that disclosed in U.S. Pat. No. 1,790,903 employed several circuits of colored incandescent light sources arrayed behind a translucent diffuser, the power supplied to such sources modulated in response to some characteristic of an 25 audio signal. Over time the construction of the display unit has remained substantially similar (e.g. U.S. Pat. No. 3,845,468) but the complexity of the control system has increased. The division of the audio signal into several frequency bands has been the most common 30 technique (e.g. U.S. Pat. No. 1,977,997), and other aspects of the audio signal, most notably the tempo or beat have been used in coordination with frequency-division to increase the complexity of the system's response.
While early systems employed a limited number of 35 sets or circuits of light sources evenly disposed about the display and produced their abstract images solely by modulating the intensity of those circuits, many recent systems have employed two dimensional arrays of light sources in which each source may be separately con- 40 trolled and the on/off condition of each light source in the array (a "pattern") can be stored in electronic memory for each of a number of such patterns. The lighting effect is therefore produced by the successive recall of patterns in order to form images moving across the 45 surface of the display. The patterns displayed, the rate of movement, and the intensity of the display all may be altered in response to one or more aspects of the audio signal.
In order to increase the variety of lighting effects, 50 recent systems have also employed separate aspects of the audio signal to control the pattern sequence and intensity (e.g. U.S. Pat. No. 3,806,873) and selectively combined two or more patterns by means of NAND (U.S. Pat. No. 4,056,805) or OR gates (U.S. Pat. No. 55 4,262,338) in order to produce new patterns related to more than one aspect of the audio signal.
It will, however, be recognized that variations in color, potentially one of the most expressive aspects of the lighting effect, are in modern systems, little more 60 than incidental to the sequence of patterns and the modulation of their intensity in response to the audio signal.
It will further be recognized that construction of the display units associated with such systems is also comparatively crude, and that the variations possible in the 65 appearance of the display unit itself (as distinguished from that in the sequence of patterns presented) are extremely limited.
It will also be recognized that while such devices are capable of complex pattern sequences, the determination of those sequences is made on the basis of a preprogrammed response to a given aspect of or given relationship between multiple aspects of an audio signal. No means is provided by which a light artist can exercise real time control in order to produce a light composition which bears a higher order relationship to, for example, a musical composition, one beyond the capability of any frequency, envelope, or tempo detector to duplicate.
It is therefore the object of the present invention to provide an improved visual display unit, whose construction affords a high degree of variety in its appearance, and in the range and subtlety of color effects possible, and further to provide the improvements to the control system required to make full use of these enhanced display capabilities and to permit an operator to exercise a heretofore unprecedented degree of control over a system capable of complex pattern sequence production.
It is a further object of the invention to make these capabilities available within a system which is economical to construct.
SUMMARY OF THE INVENTION
The visual display unit of the present invention achieves these and additional objects through a variety of techniques having synergistic benefits.
The visual display unit of the present invention presents a translucent diffuser surface to the viewer. Light baffles of an opaque material are arranged at right angles to the diffuser surface in order to form a regular pattern of adjacent isoceles triangles, each such triangle or "cell" containing separately controllable light sources. This choice of cell shape affords unique advantages in that a small number of such cells can be illuminated to form a variety of other basic geometric shapes including equilateral triangles, rhombuses, hexagons, and stars.
In order to provide a continuously variable range of color, each such cell includes four incandescent light sources, three provided with relatively broadband filters in red, amber, and green, and the fourth source employing a relatively narrow band interference filter in blue.
Additionally, a pleasing suggestion of a three-dimensional shape is provided by spacing the light source and the diffuser surface such that an uneven distribution of intensity from each light source and therefore a variation in the color mixture or "modeling" across the surface of each cell results.
Additionally, the display unit of the present invention allows the user to adjust the sharpness of the division between cells by adjusting the distance between the edge of the light baffle and the diffuser.
Additionally, the design of the display unit of the present invention also allows the relative spacing between the light baffle and the diffuser surface to be varied across the display surface, such that the blending of adjacent cell boundaries varies.
Additionally, the design of the display unit also allows the use of multiple diffuser surfaces spaced at varying distances to further increase the dimensionality of the effect.
Like prior art systems, the display unit of the present invention provides a means to vary the average power supplied to each light source in each cell, which is re3
sponsive to a control system capable of producing preprogrammed patterns.
Unlike such systems, a single value is recorded for each cell corresponding to an arbitrary color number, with a second value representing intensity. The color 5 number and intensity value specify the location in a table where the average power levels are stored for each of the four light sources in the cell which are required to produce the desired color sensation and intensity. 10
The system of the present invention allows for subtle modulation of cell color in response to prerecorded data; an operator input; or an aspect of an audio signal through the expedient of incrementing or decrementing the color number. It will be recognized that the effect achieved will be determined by the relationship between the power levels and hence color sensations recorded under adjacent color numbers and are therefore limited solely by the imagination of the operator. 20
In the preferred embodiment, the average power levels for all intensity values of the same color number will produce an identical color sensation regardless of intensity. The combination of a separate color and intensity value with such a table allows intensity to be 25 continuously varied without producing a shift in cell color caused by the inevitable changes in the color temperature of the light sources as the average power supplied to them changes.
Similarly, cell color may be varied widely without a 30 distracting change in intensity.
Additionally, the system of the present invention allows the storage of multiple color tables, such that the table consulted may be varied during operation in response to any one of a number of conditions. 35
Another aspect of the control system of the present invention resides in a novel method of operation, whereby the operator may exercise real time control over the lighting effects generated.
The control system of the present invention provides 40 an operator input device, typically a piano-type keyboard, whose output is connected to an information processing means. Data as to key closures as well as additional parameters of the closure including velocity, force, and duration are provided to the information 45 processing means. Associated with the information processor means is a memory, in which locations are provided for each key, at which the operator may preprogram the desired results of the closure including the J0 display of a "frame" or pattern or the display of a pattern sequence; the rate at which a pattern display will proceed; the relationship between the pattern sequence and those produced by the operation of other keys; and the modulation of pattern rate, intensity, or color shift J5 in response to a specified condition or relationship between multiple conditions of the operator interface controls or an external input.
The control system of the present invention, therefore, makes available to the operator via the keyboard $g or other interface device, a very large number of design elements which he may select instantly according to his creative needs, every aspect of which may be specified during the programming phase, yet which will proceed under automatic control once initiated. 65
Finally, several methods are disclosed whereby the memory, hardware, and processor requirements of the system may be minimized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a front elevation of the display unit of the present invention showing the cell geometry.
FIG. IB is a detail view of a single cell showing the light sources and filters contained therein.
FIG. 2A illustrates various geometric shapes which may be produced by the cell geometry of the present invention.
FIG. 2B illustrates the unequal intensity distribution from a single source, which results in the effect of threedimensional modeling.
FIG. 3A is a sectional view of cell construction.
FIG. 3B is a sectional view illustrating the blending effects of diffuser spacing.
FIG. 3C is a sectional view illustrating the effects of employing multiple diffusers.
FIG. 4 is a block diagram of the control system of the present invention.
FIG. 5 is a diagram of one embodiment of a hardware modifier.
Refer now to FIG. 1A, a front elevation of the display unit of the present invention; FIG. IB a detail view; and FIG. 3A a section. The viewer is presented with the neutral surface of a diffuser 101, which may be of glass or plastic or other appropriate material. Baffles 103 of a substantially opaque material are located behind the diffuser and at right angles to it, so as to form a series of compartments or "cells" 105, each such cell in the shape of an isoceles triangle, the plurality of such cells forming a regular geometrical pattern in which the hypotenuses of such triangles are adjacent. The corners of each cell may be sharp or radiussed, as desired.
Each cell 105 contains four light sources 115, 117, 119, and 121, preferably low-voltage incandescent bulbs, and each bulb is provided with a filter means, seen here as filter assemblies 116, 118, 120, and 122 (although filter materials may be applied directly to the bulb envelope).
The light sources 115, 117, 119, and 121 are supplied by power control means capable of adjusting average voltage or current in response to a control signal, such as the well-known phase control dimmer. Preferably, the light sources and their dimmers may be mounted to a common mechanical support 111, such as a printed circuit card, connected to the display unit and to conductors supplying power and control signals in a manner which allows ready replacement.
The construction of visual display unit with fourlamp compartments per se was disclosed in U.S. Pat. No. 2,340,559 and is not novel. However, unique benefits obtain from the specific geometry and from the specific combination of color filtering techniques employed by the display unit of the present invention.
Prior art display units fall into two broad categories: One type, such as disclosed in U.S. Pat. No. 3,845,468, employs a relatively large number of light sources on common electrical circuits disposed across the display unit in a fixed pattern, and hence is severely limited in the patterns which may be produced. The second type, such as disclosed in U.S. Pat. No. 2,340,559 or 4,262,338, employs light sources each on an individually selectable electrical circuit, and hence a very much larger number of patterns may be produced by energizing the appropriate combination of individual sources. However, like any dot-matrix display, prior art systems
of this type have been severely limited in their ability to produce recognizable shapes by the problem of resolution. That is, geometric shapes cannot be generated using circular display elements without both a very large number of such elements and a considerable dis- 5 tance between the unit and viewer. Thus prior art displays have severely limited the ability of the designer to exploit his individual control of light sources in order to create recognizable geometric shapes.
The display geometry of the present invention, how- 10 ever, offers unique advantages in the number of geometric shapes and effects which may be produced by a very limited number of light sources with perfect resolution.
Referring to FIG. 2A, it will be seen that only three cells need be illuminated to produce an equilateral trian- IS gle, and that progressively larger such triangles can be produced by lighting additional cells. Only two cells need be illuminated to produce a rhombus, and progressively larger such figures can also be produced by lighting additional cells. Six cells produce a hexagon, and 20 again, hexagons of increasing size can be produced with additional cells. A six-pointed star can also be generated with twelve cells, as well as in larger sizes.
Thus the display geometry of the present invention affords the designer the ability to produce the arbitrary 25 patterns of prior art systems, but also the ability to generate a variety of recognizable geometric shapes with perfect resolution using a very limited number of display cells.
Further, the display geometry of the present inven- 30 tion also offers unique motional effects, including the ability to scale such shapes up and down, and to rotate them about effective pivot points anywhere on the display.
As previously noted, prior art control systems have 35 also made comparatively limited use of color. As the subtle modulation of color is an important object of the invention, the display unit of the present invention employs a combination of color filtering techniques which has been found to reproduce the color spectrum with 40 unusual fidelity. The red, yellow, and green light sources 115,117, and 119 employ pigmented filter materials 116, 118, and 120 (such as produced by Rosco Laboratories, Port Chester, N.Y.) affording relatively broadband response. The blue light source 121, however, employs a relatively narrowband interferencetype filter material 122 (such as produced by Optical Coating Laboratories, Santa Rosa, Calif.).
The benefits in color fidelity are achieved only with this combination of filtering techniques. The use of broadband filters for all light sources results in limited color purity in the blue range. The use of narrowband interference-type filters for all colors produces uneven response at the longer wavelengths.
The appearance of the display unit of the present invention is further improved by the "modeling" of each cell to create a pleasing impression of three-dimensionality. This effect is produced by mounting the light sources 115,117,119, and 121 at a relative distance from diffuser 101 such that the distribution of light from each such source over diffuser surface 101 is uneven, as is illustrated in FIG. 2B in the case of light source 121, by lines such as 201, illustrating points of equal illumination. The degree of variation can be adjusted by changing the relative spacing between the light sources and the diffuser as well as by the use of a method of supporting the filter materials over the light sources which produces a restricting mask or aperture. The relative
offset between such sources on mounting support 111 results in color mixtures produced by illuminating multiple sources being substantially constant in the central area of the cell, but varying along its boundaries towards the color of the nearest source. This imperfect color mixture, which is at odds with the object of prior art display units, imparts an impression of three dimensional shape to each cell and produces a pleasing complexity to the appearance of the display unit as a whole not present in prior art designs.
Further, the display unit of the present invention allows the user to adjust the sharpness of the division between cells. Referring to FIG. 3B, diffuser 101 may be mounted so as to be moveable with respect to the light baffles 103. Frame 321 supporting diffuser 101 is mounted to a carrier 323, which rides along track 325 perpendicular to the plane of the display. Referring to FIG. 3B, the diffuser may be moved to create a space between the edge of the light baffles 103 and the diffuser surface. As will be apparent by examining the path of ray 301 from light source 115, light from the sources within a given cell will pass beyond the projected boundary of the light baffles 103 to overlap the area of the diffuser 101 belonging to the adjacent cell and vice versa. Similarly, rays such as 311, reflected from the light baffles themselves, which are normally trapped within the compartment will extend even farther than the direct rays from the light source. The result will be an apparent blending of the boundaries of adjacent cells to produce a "soft focus" display appearance, the degree of blending being readily varied by adjusting the distance between the diffuser surface and the baffles.
It will be recognized that a similar effect can be achieved by employing light baffles which while extending to the diffuser surface are opaque near the light sources but transparent or translucent towards the diffuser.
It will also be recognized that by varying the distance between the light baffles and the diffuser across the display, whether by curving the display surface; by employing baffles of variable height; or by a combination of the two techniques, a pleasing variation in "focus" across the display may be achieved such that, for example, the cell pattern is in relatively sharp focus at center and loses focus towards the edges.
A further means to vary the appearance of the display unit employs a plurality of diffuser surfaces at different spacings. Referring to FIG. 3C, diffuser 101 has been placed in close proximity to the baffles 103, while diffuser 303 has been spaced at a greater distance. The result is that ray 301 relatively clearly defines the sharp edge of baffle 103 on diffuser 101 while simultaneously producing a blending effect on diffuser 303. A viewer of the display sees both effects superimposed, and a more complex appearance results.
The display unit of the present invention may be employed with any type of prior art control system. The intensity of its color sources may be modulated by one or more components of an audio signal or switched by a manual keyboard. Similarly, it may be employed with a control system storing and selectively recalling patterns in response to an audio signal as disclosed in either U.S. Pat. No. 4,056,805 or 4,262,338.
In most embodiments of such systems, the on/off condition of each light source is stored separately and the color effects which are created are a byproduct of the interaction between patterns and/or modulation of