CN114902089A

CN114902089A - Digital display system and method

Info

Publication number: CN114902089A
Application number: CN202180008009.5A
Authority: CN
Inventors: K·S·奥伯拉舍尔; G·S·佩蒂特; J·M·肯普夫; M·T·戴维斯; X·周
Original assignee: Texas Instruments Inc
Current assignee: Texas Instruments Inc
Priority date: 2020-07-02
Filing date: 2021-06-21
Publication date: 2022-08-12
Also published as: WO2022005789A1

Abstract

A system has a color filter (150) having first and second segments (151, 152). The first and second segments (151, 152) allow the respective first and second wavelengths (121, 123) to pass through to the spatial light modulator (190). The first and second segments (151, 152) also reflect the second and first wavelengths (123, 121), respectively. The reflected first wavelength and the reflected second wavelength (121, 123) are recycled (127) and directed towards a color filter (150).

Description

Digital display system and method

Disclosure of Invention

A system having a color filter having a first segment and a second segment. The first and second segments allow the respective first and second wavelengths to pass through to the spatial light modulator. The first and second segments also reflect the second and first wavelengths, respectively. The reflected first wavelength and the reflected second wavelength are recycled and directed towards the color filter.

Drawings

For a detailed description of various examples, reference will now be made to the accompanying drawings in which:

fig. 1 illustrates a digital display system according to the present disclosure.

FIG. 2 shows a plan view of a fluorescent wheel (phosphor wheel).

Fig. 3 illustrates a plan view of a color filter according to the present disclosure.

Fig. 4 illustrates further operation of the image display system of fig. 1.

FIG. 5A illustrates a digital display system with a recirculating integrator rod according to the present disclosure.

FIG. 5B illustrates the reflective inner faces of the recycling integrator rod of the system of FIG. 5A.

Fig. 6A illustrates a digital display system with color filters according to the present disclosure.

Fig. 6B illustrates a plan view of the color filter of the fig. 6A system according to the present disclosure.

Figure 7A illustrates a digital display system with an involute color filter according to the present disclosure.

Fig. 7B illustrates a plan view of the color filter of fig. 7A according to the present disclosure.

Fig. 8A and 8B illustrate plan views of a section of two color filters that may be used in the system of the present disclosure.

Fig. 9A and 9B illustrate curves imaged by the color filters of fig. 8A and 8B, respectively.

Fig. 9C and 9D illustrate the effect of selecting the radius parameter of the involute filter of fig. 7B.

Fig. 10 illustrates a digital display system with a static color filter having a checkerboard pattern.

Fig. 11 illustrates a plan view of the color filter of fig. 10.

Fig. 12 illustrates a digital display system having static color filters with a striped pattern.

Fig. 13 illustrates a plan view of the color filter of fig. 12 having a stripe pattern.

Fig. 14 illustrates another example of a digital display system incorporating the color filter of fig. 13.

Fig. 15 illustrates another example of a digital display system having an actuator in the path of light reflected from a spatial light modulator according to the present disclosure.

Fig. 16 illustrates another example of a digital display system having two light sources according to the present disclosure.

Fig. 17 illustrates another example of a digital display system according to the present disclosure.

Fig. 18 illustrates a block diagram of a digital display system according to the present disclosure.

FIG. 19 illustrates a flow chart depicting one embodiment of a method for operation of the digital display system of FIG. 5A.

Detailed Description

Aspects of the present disclosure generally relate to Spatial Light Modulators (SLMs), such as Digital Micromirror Devices (DMDs) (e.g., DLPs of texas instruments), by recycling reflected light in the system and enabling other unused reflected light to be reused ^TM Devices) or liquid crystal on silicon (LCoS)) to improve efficiency.

Fig. 1 is an example of a side view of a digital display system 100, the digital display system 100 being illustrated with a path of light from a fluorescent member (in this case a rotatable fluorescent wheel 115) through a light propagation device (in this example an integrator rod 140) onto a Spatial Light Modulator (SLM) 190. Integrator rod 140 is a solid glass rod having Total Internal Reflection (TIR) characteristics. Other light propagation devices may be used, such as fly's eye arrays, hollow light tunnels, or solid light pipes. An x-y-z coordinate is provided, where the x-axis is intended to be substantially parallel to the path of light substantially collimated by first lens 130 through to second lens 230, which second lens 230 focuses the light towards integrator rod 140, for ease of explanation of the accompanying examples. The optical path is further described below. It should be noted that FIG. 1 is meant as an example only, as other embodiments may use additional reflective surfaces to change the angle of the path of light so that it reaches the SLM190 (and other additional devices, such as actuators or projection screens, as described below). Thus, the path of light (and the x-y-z coordinates) may vary in other embodiments according to the examples discussed herein.

The SLM190 includes a receiving face 191 that is substantially perpendicular to the x-axis. The receiving face 191 of the SLM extends along the y-axis over its height and along the z-axis over its width. It should be noted that the orientation and drawings are merely exemplary, as other embodiments may include different angles and different mirrors to display images on the display.

In one example, the light source 110 includes at least one blue laser diode that emits blue light 105, which blue light 105 is reflected from the dichroic mirror 112 and focused by the first lens 130 toward the fluorescence wheel 115. The dichroic mirror 112 reflects blue light and transmits yellow light. As shown, blue light 105 is shown as blue laser light and is directed vertically (i.e., along the y-axis and substantially perpendicular to the x-axis) toward a dichroic mirror 112 having a 45 ° angular tilt (relative to the x-axis) as shown in fig. 1, resulting in blue light 105 being directed toward a fluorescent wheel 115 and along a path substantially parallel to the x-axis. The fluorescent wheel 115 includes a first face 116 that reflects light substantially parallel to the x-axis and back toward the first lens 130. The fluorescent wheel 115 also includes a second face 117 substantially opposite the first face 116. First face 116 and second face 117 extend along the y-axis in their height and along the z-axis in their width (or radius). Also illustrated are a first segment 118 and a second segment 119 of the fluorescent wheel 115.

Fig. 2 shows a plan view of the first face 116 of a fluorescent wheel 115 as having a first segment 118 and a second segment 119. As shown, the reflective first section 118 is formed of a fluorescent material, while the second section 119 is formed of a transparent material. The fluorescent wheel 115 is rotatable about a central axis (shown in fig. 2 as being rotatable about the x-axis) such that the first segment 118 and the second segment 119 are positioned in the path of the blue light 105. It should be noted that although the fluorescence wheel 115 is illustrated as having two each of the first and

second segments

118 and 119, respectively, the fluorescence wheel may have an additional number of first and

second segments

118 and 119, respectively; for example, it may have three, four or more first and

second sections

118, 119, respectively. The angle through which the first segment 118 and the second segment 119 respectively extend depends on the choice of color filter.

Referring back to FIG. 1, as the fluorescent wheel 115 rotates into the path of the blue light 105, the blue light 105 is incident (strike) on the first segment 118 (FIG. 2) and is converted to yellow light 120, which includes red light 121 and green light 123. The yellow light 120 is reflected at one or more angles back from the first segment 118 toward the first lens 130 proximate to the fluorescent wheel 115. When the blue light 105 hits (encounter) the second segment 119, it is transmitted. Thus, the fluorescent wheel 115 produces alternating time slots of blue light 105 and yellow light 120. The first lens 130 collimates the incoming light and allows the light to pass through the dichroic mirror 112 to the second lens 230. Lens 230 focuses the collimated light to light receiving end 142 of integrator rod 140 where it is further homogenized or mixed. As the yellow light 120 travels through the integrator rod 140, the yellow light 120 is reflected by the sides of the integrator rod 140, becoming homogenized. The yellow light 120 passes through the integrator rod 140 and exits through its light transmissive end 144 towards the SLM 190. As discussed above, integrator rod 140 is solid and has TIR characteristics that allow yellow light 120 to undergo total internal reflection at the interface between integrator rod 140 and the air surrounding integrator rod 140. In other examples, the integrator rod is hollow and the specular interior surface propagates yellow light 120 that travels through the integrator rod. In other examples, a light tunnel or light pipe with a specular or reflective surface is used to transmit the yellow light 120 and the recycled yellow light 127 to the color filter and displayed in place of the integrator rod 140.

A color filter 150 having at least two segments, a first segment 151 and a second segment 152 respectively, is optically coupled between the integrator rod 140 and the SLM 190. Fig. 3 shows a plan view of a color filter 150 having first and

second segments

151 and 152, respectively, capable of selectively transmitting and reflecting light of a first wavelength and light of a second wavelength while allowing a third, different wavelength to pass therethrough (discussed below with respect to fig. 4). For example, as shown in fig. 1, the first segment 151 is a magenta filter that transmits red light 121 while reflecting green light 123, and the second segment 152 may be a cyan filter that transmits green light 123 while reflecting red light 121. As discussed below with respect to fig. 4, both the first segment 151 and the second segment 152 transmit blue light 105. It should be noted that although the color filter 150 is illustrated as having first and

second segments

151 and 152, respectively, additional segments may be included to allow secondary/secondary colors (secondary colors) to pass through the filter and toward the SLM. The angle through which the first segment 151 and the second segment 152 respectively extend depends on the geometrical properties of the color filter. Further, while the first segment 151 and the second segment 152 are each shown as having similar dimensions, it should be noted that the angles through which they extend may differ from one another depending on the system color performance requirements.

Referring back to FIG. 1, the color filter 150 transmits two different wavelengths simultaneously to the SLM 190. By rotating the color filter 150 about a central axis (shown in fig. 3 as being rotatable about the x-axis), different wavelengths can be transmitted to different portions of the SLM190, thereby changing the position of the segments of the color filter. For example, FIG. 1 illustrates a magenta filter 151 that transmits red light 121 to a top portion 192 (or first portion) of the SLM190 and a cyan filter 152 that transmits green light 123 to a bottom portion 194 (or second portion) of the SLM 190. The color filter 150 can be rotated such that the magenta filter 151 occupies the position of the cyan filter 152 and transmits the red light 121 to the bottom portion 194 of the SLM190, while the cyan filter 152 occupies the position of the magenta filter 151 and transmits the green light 123 to the top portion 192 of the SLM 190. As discussed above, the yellow light 120 includes green and red light. As the yellow light passes through the color filter 150, the green light of the yellow light 120 is separated from the red light of the yellow light 120, and they are sent to a separate portion of the SLM 190. When the blue light 105 passes through the filter, it passes through both the magenta filter 151 and the cyan filter 152 and is passed to both the top portion 192 and the bottom portion 194 of the SLM 190. As shown, the top portion 192 is located above the bottom portion 194 as measured along the y-axis. The relay optics 185 are used to form an image of the rotating filter pattern on the SLM 190. The rotary color filter 150 may be rotated at a speed of 60Hz, 120Hz, 180Hz, or higher.

FIG. 4 illustrates the path of light of the third wavelength (e.g., blue light) when the fluorescence wheel 115 is rotated such that the second segment 119 is in the path of the blue light 105. As shown, the blue light 105 is transmitted through a second segment 119 of the other reflective fluorescent wheel and is transmitted to be reflected by a series of

mirrors

122, 124, 126 and dichroic mirror 112. The

mirrors

122, 124, 126 and dichroic mirror 112 reflect the blue light 105 towards the second lens 230, which second lens 230 focuses the light towards the integrator rod 140. Blue light 105 is passed to light receiving end 142 of integrator rod 140. Blue light 105 is passed through integrator rod 140 and toward SLM190 to light transmissive end 144 of integrator rod 140. As shown, the blue light 105 comprises blue light and passes through both the magenta segment and the cyan segment of the color filter 150 (i.e., the first segment 151 and the second segment 151, respectively) and onto the SLM 190.

As discussed above, the fluorescent wheel 115 rotates such that the first segment 118 and the second segment 119 are in the path of the blue light 105 from the light source 110, respectively. When the blue light 105 is incident on the first segment 118, it is reflected into the system as yellow light 120. When the blue light 105 enters the second segment 119, it is allowed to pass through and be transmitted to the

mirrors

122, 124, 126 and reflected from the dichroic mirror 112 to the integrator rod 140.

Referring back to fig. 1, as the yellow light 120 impinges on the color filter 150, some of the red light 121 and green light 123 are reflected back toward the fluorescent wheel 115 as reflected light 125 that passes through other elements of the digital display system (including the second lens 230 and first lens 130, respectively, and the dichroic mirror 112, respectively) in the path from the color filter 150 to the fluorescent wheel 115, for example. The examples described herein allow the reflected light 125 to be recycled and re-transmitted as yellow light, and the yellow light 127 to be re-directed as recycled yellow light towards the color filter 150. For example, any reflected light 125 incident on the first segment 118 of the fluorescent wheel 115 is reflected toward the first lens 130 as recycled yellow light 127. The first lens 130 collimates the incoming recycled yellow light 127 and allows the recycled yellow light 127 to pass to the second lens 230 via the dichroic mirror 112. The second lens 230 focuses the collimated, recycled yellow light 127 to the light-receiving end 142 of the integrator rod 140, where it may be further homogenized or mixed. The recycled yellow light 127 is allowed to pass through the integrator rod 140 and toward the color filter 150 to the light transmissive end 144. As the recycled yellow light 127 hits the color filter 150, some of the red light 121 and green light 123 are reflected as reflected light 125 towards the fluorescent wheel 115, respectively, and the process starts over until the reflected light has dissipated into the environment. This recycling process improves the efficiency of the digital display system 100 and improves the brightness of the image on the SLM 190.

The reflected light 125 may also be incident on the second segment 119 of the fluorescence wheel 115, which reflected light 125 will be transmitted through the fluorescence wheel 115 and reflected from the

mirrors

122, 124 and 126 and pass through the dichroic mirror 112 (along the path followed by the blue light 105 in FIG. 4). A device, such as a mirror (not shown), may redirect any reflected light 125 toward the fluorescence wheel 115 to capture and recycle any reflected light 125 passing through the dichroic mirror 112 into the digital display system 100. As discussed above, the reflected light 125 is directed to the fluorescent wheel 115, which is recycled as recycled yellow light 127. Specifically, the recycled yellow light 127 is reflected toward the first lens 130. The first lens 130 collimates the incoming recycled yellow light 127 and allows the recycled yellow light 127 to pass to the second lens 230 via the dichroic mirror 112. The second lens 230 focuses the recycled yellow light 127 to the light-receiving end 142 of the integrator rod 140, where it can be further homogenized or mixed. The recycled yellow light 127 is allowed to pass through the integrator rod 140 and toward the color filter 150 to the light transmitting end 144. As the recycled yellow light 127 hits the color filter 150, some of the red light 121 and green light 123 are reflected as reflected light 125 towards the fluorescent wheel 115, respectively, and the recycling process starts over until the reflected light has dissipated into the environment. This recycling process improves the efficiency of the digital display system 100 and improves the brightness of the image on the SLM 190.

The color filter 150 rotates in synchronization with the operating speed of the SLM190 to project red, green, and blue light to be integrated as a composite color image on the display surface. During the first time slot, the SLM190 simultaneously forms a red image using red light 121 at the top portion 192 and a green image using green light 123 at the bottom portion 194. During the second time slot, the SLM forms a blue image using blue light 105 at both the top portion 192 and the bottom portion 194. The rotation of the color filter 150 is detected by an index mark detector or some other sensing mechanism such as a measurement or signal from a color wheel motor. For example, one such detector may be an Infrared (IR) sensor that monitors index marks on the motor hub.

Relay optics 185 is also shown in fig. 1 and 4, the relay optics 185 relaying an image of the wheel pattern on the SLM 190. As discussed above, the SLM190 may be a Digital Micromirror Device (DMD) (e.g., Texas instruments DLP) ^TM Device) of an N x M array of micromirrors. The DMD chip has hundreds of thousands of micromirrors on its surface arranged in a rectangular array. The micromirrors correspond to pixels in the image to be displayed. The micromirrors can individually rotate to an on (on) or off (off) state. The diameter of the micromirror itself is about 16 microns. Each micromirror is mounted on a yoke, which in turn is connected to two support posts by flexible torsion hinges and intermediate twistable torsion members. By tilting the micromirrors, each micromirror can be switched between on and off states. In the on state, light from the color filter 150 is reflected into the lens, making the pixel appear bright on the screen. In the off state, light from the color filter 150 is directed elsewhere (typically onto a heat sink) so that the pixel appears dark.

In other examples, other types of spatial light modulator devices may be used. For example, liquid crystal on silicon (LCoS) devices may be used. These devices, such as digital micromirror devices, are reflective elements that can be individually controlled to modulate an image into projected light. LCoS is a reflective active matrix liquid crystal display using liquid crystals on top of silicon. Instead of a dynamic mirror, the controller may control the characteristics of the pixels to turn them on or off to redirect light towards a projection screen (not shown).

Fig. 5A and 5B illustrate an alternative digital display system 200, the digital display system 200 incorporating an integrator rod 240, the integrator rod 240 including an inner face 260 having a reflective surface (described below). As with the integrator rod of fig. 1 (integrator rod 140), integrator rod 240 extends along the x-axis and includes a light receiving end 242 and a light transmitting end 244. Unlike integrator rod 140, integrator rod 240 has an aperture at light receiving end 242. As shown in FIG. 5A, the light-receiving end 242 is close to the fluorescence wheel 115, while the light-transmitting end 244 is close to the SLM 190. Light receiving end 242 has an inner face 260 that transmits light toward light transmitting end 244. FIG. 5B illustrates a plan view taken along line 5B-5B of FIG. 5A, showing the inner face 260 as a reflective surface with apertures 250, the apertures 250 facilitating the entry of the yellow light 120 and the blue light 105 into the integrator rod. Although the apertures 250 are illustrated as circular, other embodiments may include apertures that are oval, triangular, quadrilateral, or any other shape suitable for the application.

Integrator rod 240 is a solid glass rod positioned between light-receiving end 242 and light-transmitting end 244 and has Total Internal Reflection (TIR) characteristics. The inner face 260 is substantially reflective and reflects the reflected light 125 toward the light transmissive end 244. The reflective inner face 260 reduces the amount of reflected light 125 that travels to the fluorescent wheel 115 (shown in FIG. 1). Light reflected from inner face 260 of integrator rod 240 is homogenized and directed and transmitted as recycled yellow light 127 toward light transmitting end 244. As with the yellow light 120 (FIG. 1), the recycled yellow light 127 impinges on the color filter 150, where some of the red and green light (121 and 123, respectively) is transmitted toward the SLM190, while some of the red and green light is reflected from the color filter as reflected light 125, and the recycling process begins anew until the reflected light has dissipated into the environment. This recycling process improves the efficiency of the digital display system 200 and improves the brightness of the SLM 190.

Integrator rod 240 may not have a reflective inner face 260; instead, it may have a substantially reflective film or coating on the outer surface 262 of integrator rod 240. As discussed above, any reflected light 125 within the integrator rod will be reflected toward the color filter 150 as recycled yellow light 127. The light is passed through the color filter 150 towards the SLM 190. Furthermore, as discussed above, a hollow light tunnel may be used as an alternative to a glass rod.

In yet another example, as shown in fig. 6A and 6B, an alternative digital display system 400 has a color filter 350, the color filter 350 having first, second, and third segments (351, 352, 353, respectively), the color filter 350 being disposed between the integrator rod 240 (discussed above with respect to fig. 5A and 5B) and the SLM 190. In another example, color filter 350 is used with integrator rod 140. As illustrated in fig. 6A and 6B, the first, second, and

third segments

351, 352, 353, respectively, are in an alternating sequence. As shown, and similar to the color filter 150 of fig. 3, the color filter 350 has a first segment 351, a second segment 352, and a third segment 353 capable of transmitting light of first, second, and third wavelengths, respectively. The first, second and third segments 351,352, 353 are also all capable of transmitting light of a fourth wavelength that is different from the first, second and third wavelengths. For example, as shown in fig. 6A, the first segment 351 may be a magenta filter transmitting red light 121 and blue light 105 while reflecting green light 123, and the second segment 352 may be a cyan filter transmitting green light 123 and blue light 105 while reflecting red light 121. In addition, the color filter 350 has a third section 353 transmitting yellow light 120 (including red and green light) and blue light 105. The third section 353 may be a transparent section. As shown in FIG. 6A, color filter 350 transmits at least three different wavelengths simultaneously to different portions of SLM 190. In addition, color filter 350 may be rotatable about an axis (fig. 6B) similar to color filter 150 of fig. 3.

As the color filter 350 rotates, different wavelengths of light are transmitted to different portions of the SLM 190. For example, while FIG. 6A shows a first segment 351 transmitting red light 121 to a top portion 192 of the SLM190, a second segment 352 transmitting green light 123 to a bottom portion 194 of the SLM190, and a third segment 353 transmitting yellow light 120 to a middle portion 193 of the SLM190, the color filter 350 can be rotated so that different wavelengths can be transmitted to different portions (192, 193, 194) of the SLM 190.

As discussed above with respect to fig. 4, the fig. 6A configuration allows blue light 105 to pass through the fluorescence wheel 115, reflect from the

mirrors

122, 124, 126 and dichroic mirror 112, and pass along the x-axis and toward the SLM190 toward and through the integrator rod 240 (fig. 5A). As discussed above, the 6A phosphor wheel 115 rotates and the blue light 105 either enters the first segment 118 and is converted to yellow light 120, or the blue light 105 passes through the second segment 119 and is directed to the

mirrors

122, 124, 126 and dichroic mirror 112; blue light 105 is then reflected towards integrator rod 240 and towards involute color filter 450. The blue light 105 passes through first, second and third segments (351, 352 and 353, respectively) to the SLM 190. Thus, the illustrated digital display system 400 can transmit at least four wavelengths of light. Other embodiments may include archimedes color filters as disclosed in commonly assigned U.S. patent No. 6,642,969B2, which is incorporated herein by reference in its entirety, as well as any color filters discussed and disclosed herein. Further, while discussed and described as transmitting at least four different wavelengths of light, other embodiments may include additional and/or different wavelengths, depending on the intended operation.

Figures 7A and 7B illustrate another example of a digital display system 500 having an involute color filter 450 disposed between an integrator rod 240 (discussed above with respect to figures 5A and 5B) and SLM 190. In other examples, involute color filter 450 is used with integrator rod 140 (fig. 1). FIG. 7B illustrates a plan view of an involute color filter 450, such as with an involute color structure that facilitates light transmission from light source 110 to SLM 190. As shown, the involute color filter 450 has a circular involute design comprising ten equal segments alternating between

segments

451 and 452. The involute color filter 450 has a diameter D of 80mm (as measured on the y-axis and z-axis defined above with respect to fig. 1) with a 20mm diameter (D1) central cutout 455 for attachment to the rotatable member. The involute color filter 450 may also have an edge exclusion 460 with timing marks 461. Each of the

sections

451, 452 is arranged as a spiral (spiral), each spiral adjoining an adjacent spiral. Each helix is defined by the following equation: xi ═ a (cos (t) + t sin (t)) and yi ═ a (sin (t) -t ═ cos (t)), where "a" is a variable adjusted based on the number of segments, the filter diameter and the central cut diameter, and "t" is a parametric equation parameter (ranging from 0 to infinity). Thus, the diameters of the color filters and the center cut and spiral may be different from the illustrated example.

The involute filter 450 improves the archimedes filter because the horizontal lines between colors are flatter in the projected image. This results in a better color to area ratio as the involute filter 450 rotates, because as each color passing through the involute filter 450 sweeps across the light transmitting end 244 of the integrator rod 240 (fig. 5A), the area ratio between colors is closer to a constant ratio than the area ratio between colors of a non-involute filter (e.g., an archimedes filter). The improved area ratio increases the efficiency of the recycling process, since a more variable color area ratio will result in brightness fluctuations over time. By reducing the area ratio variability, the involute color filter 450 can be used to reduce any brightness fluctuations.

As shown in fig. 8A and 8B, the archimedes color filter 550 (fig. 8A) having first and second segments (551 and 552, respectively) and the involute color filter 450 (fig. 8B) having first and second segments (451 and 452, respectively) are illustrated side-by-side. As shown,

segments

551 and 552 of archimedes filter 550 spiral once toward the center. Thus, segment 551 and segment 552 only traverse (reverse) the 0 ° marker once. The involute color filter 450, on the other hand, has

segments

451 and 452 that spiral at least twice toward the central cut 455, allowing each

segment

451 and 452 to traverse the 0 mark 3 times. The involute color filter 450 thus allows the radius of curvature to be increased. The larger the radius of curvature, the flatter the curve (which can be measured by the curve height).

Fig. 9A and 9B show the curved line HLA imaged from the archimedes filter 550 (fig. 9A) onto the SLM and the curved line HLB imaged from the involute filter 450 (fig. 9B) onto the SLM, with horizontal lines representing reset blocks of different values of the parameter "a". As shown, the curvature radius of the curved line HLA imaged from the archimedes color filter 550 (fig. 9A) is smaller than the curvature radius of the curved line HLB imaged from the involute color filter 450 (fig. 9B). As a result, the bent line HLA imaged from the archimedes color filter 550 (fig. 9A) has a larger curvature than the bent line HLB imaged from the involute color filter 450 (fig. 9B). In other words, the involute color filter 450 (fig. 9B) produces a flatter (and thus improved) curved line HLB as compared to the curved line of the archimedes color filter 550 (fig. 9A). As a result, there will be a non-uniform color area ratio between the two colors as one segment of the archimedes filter 550 transitions to the next. On the other hand, the involute color filter 450 has a smoother transition because its color area ratio is more uniform than that of the archimedes color filter 550. In addition, the inactive time of each micromirror in the DMD may be reduced. Since the transition between colors is smoother, fewer micromirrors in the DMD need to be turned off, increasing the brightness of the overall image. Also, the inactive time of individual reflective elements in an LCoS SLM may be reduced. Since the transition between colors is smoother, fewer pixels in the LCoS need to be turned off, thereby increasing the brightness of the overall image.

In addition, the geometry of the involute color filter 450 allows the horizontal tangent of the helix at the light transmitting end of the integrator rod to remain in a near-center (FIG. 9B) position on the y-axis. As the helix is scanned vertically, the horizontal tangent to the archimedean helix is off-center along the y-axis. The involute color filter 450 thus also increases the color-to-area ratio error and increases the complexity of considering the spiral when loading the data that generates the image.

The number of segments, filter diameter, and cut diameter are all variables that will be considered for the involute filter in embodiments of the involute filter. In general, as shown in fig. 9C, with the radius of parameter a (in the equation: xi (cos (t) + t sin (t)) and yi (a (sin (t) -t) cos (t)) increase (as shown along the x-axis of the graph), the number of segments also increases, as shown graphically in fig. 9D, since the radius of curvature of the horizontal line HLB is reduced (fig. 9B) the color area ratio is more uneven, the larger the curve height of the HLB (FIG. 9B). The more uneven the color area ratio, however, the disadvantage of the smaller number of segments includes a lower frame rate.

Fig. 10 illustrates a digital display system 600 incorporating a static color filter 650 and an actuator 670, the actuator 670 being rotatable about the x-axis, the y-axis, or both. Static color filter 650 does not have a rotating (spin) color filter wheel, such as color filter 150 (fig. 1), but rather remains fixed at or near light-transmitting end 244 of integrator rod 240 (fig. 5A), while actuator 670 comprises a piece of glass that can divert/move (shift) all or part of the light beam onto the display, as disclosed in commonly assigned U.S. patent application publication No. 2019/0227261, which is incorporated herein by reference in its entirety. For example, the actuator may be a transparent optical element using refraction across a width of the actuator 670, the width being defined by a distance between a first surface 671 of the actuator 670 and a second surface 672 opposite the first surface 671 of the actuator 670. Diffraction may cause the entire beam 660 to move a small fraction of the pixels on the SLM. For example, the actuator may refract 1/4 pixels of light beam 660 on the horizontal and vertical axes. In this manner, the actuator 670 may tilt 1/4 pixels down and to the left, up and to the right, and down and to the right. Thus, one pixel (not shown) in the SLM can form four different images, thereby increasing the resolution of the resulting image by a factor of 4.

The operation of the digital display system of fig. 10 is otherwise similar to the digital display system 100 described above with respect to fig. 1-4. As shown, the blue light 105 is shown as blue laser light and is directed vertically (i.e., along the y-axis and substantially perpendicular to the x-axis) toward a dichroic mirror 112, which in fig. 1 has a 45 ° angular tilt (relative to the x-axis) resulting in the blue light 105 being directed toward a fluorescent wheel 115 and along a path substantially parallel to the x-axis.

The fluorescent wheel 115 includes a first face 116 that reflects light substantially parallel to the x-axis. The fluorescent wheel 115 also includes a second face 117 substantially opposite the first face 116. First face 116 and second face 117 extend along the y-axis in their height and along the z-axis in their width. When blue light 105 is incident on the first segment 118 (fig. 2), the blue light 105 is converted to yellow light 120, the yellow light 120 being a mixture of red and green light (121, 123, respectively). The yellow light 120 is reflected from the first segment 118 at one or more angles toward a first lens 130 proximate to the fluorescent wheel 115. The first lens 130 collimates the incoming light and allows the light to pass to the second lens 230. Second lens 230 focuses the collimated light onto light receiving end 242 of integrator rod 240 where it may be further homogenized or mixed. The light is allowed to pass through integrator rod 240 and toward SLM190 to light transmitting end 244. The yellow light 120 travels through the integrator rod 240. As the yellow light 120 travels through the integrator rod 240, the yellow light 120 is reflected by the sides of the integrator rod 240, becoming homogenized. The color filter 650 has at least two segments (first segment 651 and second segment 652, respectively) and is disposed between the integrator rod 240 and the SLM 190. A plurality of rays for a large number of image pixels may pass through the actuator 670. By using refraction, different wavelengths can be directed to different parts of the SLM 190.

Fig. 11 illustrates a plan view of a static (or non-rotating) color filter 650 having a checkerboard pattern. Color filter 650 may be used in any of the systems discussed and described herein (e.g., digital display system 100 (fig. 1) or digital display system 200 (fig. 5A and 5B)), as may any other color filter described herein. Static color filter 650 remains fixed at or near light-transmitting end 244 of integrator rod 240 and does not rotate as color filter 150 (fig. 1). As shown in fig. 11, the static color filter 650 has a magenta 651 and cyan 652 pattern alternating in a checkerboard fashion.

Referring back to fig. 10, the path of light of the third wavelength that does not impinge on the first segment 118 of the fluorescent wheel 115 is similar to the path discussed above with respect to fig. 4. That is, blue light 105 (FIG. 4) is transmitted through the second segment 119 of the other reflective fluorescent wheel and is transmitted and reflected by a series of

mirrors

122, 124, and 126 and dichroic mirror 112. The

mirrors

122, 124, 126 and dichroic mirror 112 reflect the blue light 105 (FIG. 4) toward the second lens 230, and the second lens 230 focuses the light toward the integrator rod 240. Blue light 105 is passed to light receiving end 242 of integrator rod 240. Light is allowed to pass through the integrator rod 240 and towards the SLM190 to the light transmissive end 244. As discussed above with respect to fig. 4, blue light 105 comprises blue light and passes through cyan and magenta segments of color filter 650 (i.e., first and

second segments

651 and 652, respectively) and onto SLM 190. In alternate time slots, blue light 105 or yellow light 120 strikes SLM 191, as discussed above.

Similar to the digital display system 200 discussed above with respect to fig. 5A-5B, as the yellow light 120 impinges the color filter 650 of fig. 10, some of the red and green light (121 and 123, respectively) is reflected as reflected light 125 toward the integrator rod 240. The reflected light 125 is reflected as yellow light from the inner face 260 (fig. 5A and 5B) toward the light transmissive end 244 and is redirected as recycled yellow light 127 toward the color filter 650. As with the yellow light 120, the recycled yellow light 127 impinges on the color filter, where the red and green light (121 and 123, respectively) is transmitted toward the SLM 190. As the recycled yellow light 127 hits the color filter 150, some of the red and green light (121 and 123, respectively) is reflected as reflected light 125 towards the fluorescent wheel 115, and the process starts over until the reflected light has dissipated into the environment. This recycling process improves the efficiency of the digital display system 600 and improves the brightness of the image on the SLM 190.

Fig. 12 illustrates another example of a digital display system 700, wherein the digital display system 700 can include the fig. 11 color filter 650. In this example, the fluorescent wheel 215 has a first segment 218 and a second segment 219 that include reflective fluorescent material and reflective material, respectively. Because blue light 105 can be reflected by second segment 219 of fluorescent wheel 215 directly toward integrator rod 240 through the use of second lens 230 (which allows yellow light 120 and blue light 105 to focus), this embodiment can eliminate the need for

mirrors

122, 124, and 126 (e.g., FIG. 10) because dichroic mirror 212 is offset from the center of first lens 130. Further, the dichroic mirror 212 may be made of a smaller mirror (compared to the dichroic mirror 112 of fig. 1) such that the blue light 105 reflected from the fluorescent wheel 215 is reflected from the lens 130 to the lens 230 above the dichroic mirror without impinging on the dichroic mirror 212.

The operation of the digital display system 700 of fig. 12 is similar to the example discussed above, except for the blue light path shown in fig. 4. Specifically, blue light 105 is shown as blue laser light and is directed vertically (i.e., along the y-axis and substantially perpendicular to the x-axis) toward dichroic mirror 212, which in fig. 12 has a 45 ° angular tilt (relative to the x-axis) resulting in blue light 105 being directed toward fluorescent wheel 215 and along a path substantially parallel to the x-axis. The fluorescent wheel 215 includes a first segment 218 having a reflective fluorescent material. When blue light 105 is incident on the first segment 218, the blue light 105 is converted to yellow light 120, the yellow light 120 being a mixture of green and red light (121, 123, respectively). The yellow light 120 is transmitted toward the first lens 130. The first lens 130 collimates the incoming light and allows the light to pass to the second lens 230. Second lens 230 focuses the collimated yellow light onto the light-receiving end 242 of integrator rod 240, where it may be further homogenized or mixed. Light is allowed to pass through the integrator rod 240 and towards the SLM190 to the light transmissive end 244.

The fluorescent wheel 215 also includes a second segment 219 that is substantially reflective. When the blue light 105 is incident on the second segment 219, the blue light 105 is reflected substantially along the x-axis towards the first lens 130. First lens 130 collimates the incoming light and allows the light to pass to second lens 230 and toward light receiving end 242 of integrator rod 240. The light is allowed to pass through the integrator rod 240 and towards the SLM190 to the light transmitting end 244.

The color filter 650 has at least two segments (first segment 651 and second segment 652, respectively) and is disposed between the integrator rod 240 and the SLM 190. A plurality of rays for a large number of image pixels may pass through the actuator 670. By using refraction, different wavelengths can be directed to different parts of the SLM 190.

Similar to digital display system 600 discussed above with respect to fig. 10, as yellow light 120 impinges on color filter 650 of fig. 10, some of the red and green light (121 and 123, respectively) is reflected toward integrator rod 240 as reflected light 125. The reflected light 125 is reflected from the inner face 260 (fig. 5A and 5B) toward the light transmissive end 224 as recycled yellow light 127, and is redirected toward the color filter 650 as recycled yellow light 127. As with the yellow light 120, the recycled yellow light 127 impinges on the color filter, where the red and green light (121 and 123, respectively) is transmitted toward the SLM 190. As the recycled yellow light 127 hits the color filter 650, some of the red and green light (121 and 123, respectively) is reflected as reflected light 125 towards the fluorescent wheel 115, and the process starts over until the reflected light has dissipated into the environment. This recycling process improves the efficiency of the digital display system 700 and improves the brightness of the image on the SLM 190.

Fig. 13 illustrates a plan view of different static color filters 750 having a stripe pattern that may be used in any of the digital display systems discussed herein (e.g., 100, 200, 600, and 700). The operation of the striped static color filter 750 is similar to that of the checkerboard static color filter 650 (FIG. 10) and the actuator 670 may be used to similarly display different wavelengths of light to the SLM 190. As shown, the striped static color filter 750 includes alternating first 751 and second 752 segments capable of transmitting and reflecting light of a first wavelength and light of a second wavelength. For example, as shown in fig. 13, the first segment 751 may be a magenta filter that transmits red-blue light 121 (fig. 1) while reflecting green light 123 (fig. 1), and the second segment 752 may be a cyan filter that transmits green-blue light 123 (fig. 1) while reflecting red light 121 (fig. 1). As discussed above with respect to the

digital display systems

100, 200, 500, 600, and 700, the yellow light 120 and the recycled yellow light 127 pass through the static color filter, thereby increasing the brightness of the overall

digital display systems

100, 200, 600, and 700. It should be noted that the example of fig. 12 may be used with a third segment that is capable of transmitting a third wavelength.

Fig. 14 illustrates an alternative example in which a digital display system 800 has two

light sources

210 and 110, which are blue laser diodes capable of emitting blue light 105. The two

light sources

210 and 110 may be implemented in other embodiments discussed herein. As shown in fig. 12, the dichroic mirror 112 has a first surface 113 and a second surface 114. The first light source 110 is situated such that the blue light is directed vertically (i.e. substantially perpendicular to the x-axis) towards the first surface 113, which first surface 113 is shown in fig. 14 as having an angular tilt (relative to the x-axis) of 45 ° resulting in the blue light 105 being directed towards the fluorescent member 315 and along a path substantially parallel to the x-axis. The fluorescent member 315 includes a first face 316 and a second face 317, the first face 316 converting the blue light 105 to yellow light 125 and reflecting the yellow light 125 substantially parallel to the x-axis, the second face 317 being substantially opposite the first face 316. The yellow light 125 passes through the first lens 130, the dichroic mirror 112, and the second lens 230 to the integrator rod 240. The second blue diode 210 is located above the dichroic mirror 112 and reflects from the second surface 113 of the mirror 112 towards the integrator rod 240 and onto the SLM190, the mirror 112 having a 45 ° tilt. Unlike the fluorescent wheel 115 of fig. 1, the fluorescent member 315 of the digital display system 300 is constructed from a single piece of solid fluorescent material. This configuration may eliminate any mechanical device required for the rotation of the fluorescent wheel 115 of FIG. 1, and is therefore a static or non-rotating component. This architecture also eliminates the need for a series of

mirrors

122, 124, and 126 (fig. 4). Furthermore, because first segment 751 and second segment 752 of color filter 750 transmit blue light 105, digital display system 800 may transmit at least three wavelengths of light (e.g., red, green, and blue) to SLM190 by simultaneously causing two light sources 110 to simultaneously direct blue light 105 toward mirror 112. In addition, if the color filter 750 is replaced with the color filter 350 (fig. 6A and 6B), and the color filter 350 transmits yellow light 120 in addition to red light 121, green light 123, and blue light 105, the digital display system 800 of fig. 14 can simultaneously transmit at least four different wavelengths of light.

The operation of the digital display system 800 is otherwise similar to the digital display system 200 of fig. 5A. For example, when the blue light 105 is incident on the fluorescent material, the blue light 105 is converted into yellow light 120 and reflected toward the first and

second lenses

130 and 230. The yellow light 120 is focused and reflected toward and through the recycling integrator rod 240 along the x-axis and toward the SLM 190. As discussed above with respect to digital display system 200, certain wavelengths of yellow light 120 pass through the color filter (color filter 750 of fig. 12), while certain wavelengths are reflected back toward the inner surface of recycling integrator rod 240. The reflected light 125 is recycled by the recycling integrator rod 240 and the recycled yellow light 127 passes through the static color filter, thereby increasing the brightness of the overall digital display system 800.

The digital display system 900 of fig. 15 includes an actuator 670 placed in the path of light after reflection from the SLM190 (e.g., DMD or LCoS). In this example, the SLM190 surface projects two display images created from incoming image frames and divided into sub-frames for each displayed high resolution image frame. After the first sub-frame is displayed for a portion of the frame image time, the actuator 670 positioned in the projection path moves the position of the SLM frame in the horizontal direction by an amount (e.g., a pixel or less than a pixel distance, such as half a pixel) and displays the second sub-frame for a second portion of the frame time. Furthermore, the sub-frame may also be shifted in the vertical direction, for example by half a pixel. By moving back and forth, the image resolution in the image observed by the observer is increased by a factor of, for example, 2 compared to the number of physical mirrors. In this way, a smaller resolution SLM (e.g., 1/2 mirror count) can be used to produce an image with a visual resolution higher than that obtained from just the number of elements in the SLM.

For example, with respect to color filter 750 (fig. 15), a first image time may image red and green; the second image time may optically shift the image horizontally by 1 pixel and place the red on top of the green and the green on top of the red. The third image time may optically shift the image horizontally and vertically 1/2 pixels (or 0.5 pixels). The fourth image time may optically shift the image by 1.5 pixels horizontally and vertically. The third and fourth image times and the displacement will provide bi-directional optical super resolution. For blue, the image time may be divided into two, and the first and second image times will image blue without movement, and the third and fourth image times will have a movement of 0.5 pixels both horizontally and vertically. This optical movement improves the resolution of the image.

Although the

color filters

650 and 750 are discussed and described as having a checkerboard configuration and a vertical stripe configuration, other embodiments may include a horizontal stripe configuration and/or an alternating pattern of different shapes. For example, while the color filter 650 of fig. 10 is illustrated as a checkerboard pattern having

square segments

651 and 652, it should be appreciated that a square may be triangulated in half at 45 ° angles and each triangle may represent a segment. Other shapes and patterns may be included based on the intended operation of the digital display system. Although the digital display system 900 is illustrated as having two light emitting

diodes

110 and 210, it should be noted that the digital display system 900 may be implemented with one light emitting diode.

In another embodiment, checkerboard or stripe filters may be coupled to the actuators. For example, fig. 16 shows an actuated color filter 850 attached directly to a translation actuator 770. The translation actuator moves the actuated color filter 850 slightly in the y-direction and the z-direction (in the case of a checkerboard pattern (e.g., fig. 11)) or in the y-direction only or in the z-direction only (in the case of a stripe pattern (e.g., fig. 13)). Other mechanisms by which the actuating color filter 850 and the actuator 770 are coupled are intended to fall within the scope of the present disclosure. In operation of the digital display system 950, the actuator 770 translates appropriately in the plane of the y-axis and z-axis to move the filter 650 and direct the red 121, green 123, and blue 105 light to the SLM 190.

The operation of the digital display system 950 is otherwise similar to the digital display system 800 of fig. 14. For example, when the blue light 105 is incident on the fluorescent material, the blue light 105 is converted into yellow light 120 and reflected toward the first and

second lenses

130 and 230. The yellow light 120 is focused and reflected toward and through the recycling integrator rod 240 along the x-axis and toward the SLM 190. As discussed above with respect to digital display system 200, certain wavelengths of yellow light 120 pass through the color filter (color filter 850), while certain wavelengths are reflected back toward the inner surface of recycling integrator rod 240. The reflected light 125 is recycled by the recycling integrator rod 240 and the recycled yellow light 127 passes through the static color filter, thereby increasing the brightness of the overall digital display system 950.

FIG. 17 illustrates another example of a digital display system 975 having a light source 110 with a substantially straight path along the x-axis toward the SLM 190. Digital display system 975 does not use dichroic mirror 112 of digital display system 100 (fig. 1) and directs light through fluorescence wheel 415, first lens 130, second lens 230, integrator rod 240, color filter 350, and relay optics 185 toward SLM190 for imaging on SLM 190. Blue light 105 from light source 110 is directed to a fluorescent wheel 415 having first and second segments (418 and 419). When the first segment 418 with the phosphor is in the path of light 105, it is converted to yellow light 120. The yellow light 120 is directed towards and through the integrator rod 240, and the integrator rod 240 is further directed towards the color filter 350 and out towards the SLM190 through the relay optics 185.

As with

digital display systems

100, 200, 400, 600, 800, 900 and 950, reflected light 125 can be recycled to improve the efficiency of digital display system 950 and to improve brightness on the SLM. As the yellow light 120 strikes the color filter 350, some of the red and green light (121 and 123, respectively) is reflected toward the integrator rod 240 as reflected light 125. The reflected light 125 is reflected from the inner face 260 (fig. 5A and 5B) toward the light transmissive end 244 as yellow light 127 and redirected toward the color filter 350 as recycled yellow light 127. As with the yellow light 120, the recycled yellow light 127 impinges on the color filter, where the red and green light (121 and 123, respectively) is transmitted toward the SLM 190. As the recycled yellow light 127 hits the color filter 150, some of the red and green light (121 and 123, respectively) is reflected as reflected light 125 towards the fluorescent wheel 415, and the process starts over until the reflected light has dissipated into the environment.

FIG. 18 illustrates an example of a circuit 1190 for use with any one or combination of the digital display systems described above. A processor 1191, such as a microprocessor, mixed signal processor, digital signal processor, microcontroller, or other programmable device is provided and executes instructions that cause it to output a digital video signal for display. Various sources may provide digital video signals labeled video input in the figures, including internet browsers, files stored in video cards, flash memory cards, Universal Serial Bus (USB) drives, and the like, High Definition Multimedia Interface (HDMI) or other inputs, cameras, camcorders, and the like. Processor 1191 is coupled to digital controller 1193, where digital controller 1193 is another digital video processing integrated circuit. An analog controller 1197 is also provided. Analog controller 1197 controls the intensity and power of light source 110. Digital controller 1193 operates SLM 290, for example, by switching micro mirrors to an on or off state. The analog controller 1197 also provides power and analog signals to the SLM 190. Light from the illumination source 110 is input to an illumination component 1202, such as the first and second lenses 130, 230 (fig. 1), the integrator rods 140 and 240 (fig. 1 and 5A, respectively), and the color filters 150 (fig. 1), 350 (fig. 6A), 450 (fig. 7), 650 (fig. 10), and/or 750 (fig. 13). Light is incident on SLM190 and reflects the light to projection optics 1203 for further processing for projection on a screen (not shown). Together, the

integrated circuits

1193, 1197 cause the SLM190 and optical components to operate to project a digital video signal as an image.

Integrated circuits

1193, 1197 may comprise a general purpose microprocessor, digital signal processor, microcontroller, or other device capable of executing instructions retrieved from a computer readable storage medium. Processor architectures typically include execution units (e.g., fixed point, floating point, integer, or other execution units), storage devices (e.g., registers or memory), instruction decoding, peripherals (e.g., interrupt controllers, timers, and/or direct memory access controllers), input/output systems (e.g., serial ports, parallel ports, etc.), and various other components and subsystems. The

integrated circuits

1193, 1197 may include

storage devices

1194, 1196 as non-transitory computer-readable storage media suitable for storing executable instructions. The

storage devices

1194, 1196 may include volatile memory (e.g., random access memory), non-volatile storage devices (such as a hard disk drive, optical storage device (e.g., a Compact Disk (CD) or Digital Versatile Disk (DVD) drive), flash memory, read only memory), or a combination thereof.

Fig. 19 illustrates an example of a process 1600 by which, for example, the digital display system 200 operates. At 802, blue light is directed toward a fluorescence wheel, such as fluorescence wheel 115. At 804, if the first segment is positioned in the path of the blue light, the blue light is converted to yellow light and directed toward the integrator rod. At 806, if the second segment is positioned in the path of the blue light, the blue light is directed toward and transmitted through the recycling integrator rod. At 808, both the yellow and blue light pass through the integrator rod. At 810, the yellow light impinges on a first segment that allows the first wavelength to pass 812 and reflects the second wavelength 814. At 811, the yellow light impinges on a second segment that allows the second wavelength to pass 812 and reflects the first wavelength 814. At 808, any reflected light is recycled as yellow light and directed toward the first and second segments of the color filter. Blue light impinging on either the first segment or the second segment is allowed to pass 812. At 816, light passing through the first and second segments of the color filter is imaged onto the SLM190 (e.g., FIG. 1). The process of 808, 810, 811, and 814 can be repeated until all reflected light has been transmitted 812 to the SLM or has been dissipated or otherwise escapes the system at step 816. Light passing through the first and second segments of the color filter is imaged onto the SLM.

The above discussion is meant to be illustrative of the principles and various examples consistent with the present disclosure. Many variations and modifications are possible. For example, while cross-sectional dimensions of various components (e.g., color filters, phosphor wheels/members, integrator rods, etc.) have been described with respect to one another, other embodiments may include different relative dimensions. Further, other embodiments may include different components in the systems described above. For example, and as described above, integrator rod 140 may be used in any of the above-described digital display systems (100, 200, 400, 500, 600, 800, 900, 950, and 975), such as recirculating integrator rod 240 (fig. 5A). Further, the above-described examples have two light sources 110 (e.g., fig. 14) and stationary or rotating fluorescent members 315 (e.g., fig. 14), 215 (e.g., fig. 1) or wheels 115 (e.g., fig. 1), which may be implemented in any of the above-described digital display systems (e.g., 100, 200, 400, 500, 600, 700, 800, 900, 950, and 975). Similarly, any of the above-described color filters (e.g., 150, 350, 450, 550, 650, 750) can be implemented in any of the above-described digital display systems (e.g., 100, 200, 400, 500, 600, 700, 800, 900, 950, and 975). It is therefore intended that the following claims be interpreted to embrace all such variations and modifications.

Moreover, certain terms are used throughout the description and claims to refer to particular system components. It is understood that different parties may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the present disclosure and claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to.

Claims

1. A system, comprising:

a color filter, comprising:

a first segment configured to transmit a first wavelength and reflect a second wavelength, an

A second segment configured to transmit the second wavelength and reflect the first wavelength,

wherein the first segment and the second segment are further configured to transmit a third wavelength; and

a light propagating device disposed between an illumination source and the color filter, the light propagating device configured to transmit recycled light from the reflected first wavelength and the reflected second wavelength as recycled light to the color filter.

2. The system of claim 1, further comprising a fluorescent wheel configured to reflect wavelengths toward the color filter.

3. The system of claim 2, wherein the fluorescence wheel is configured to cycle the wavelengths of the first and second reflections.

4. The system of claim 1, wherein the light propagation device is a recycling integrator rod configured to recycle the first reflected wavelength and the second reflected wavelength.

5. The system of claim 1, further comprising a spatial light modulator configured to receive light at the first, second, and third wavelengths.

6. The system of claim 1, further comprising a second illumination source.

7. The system of claim 1, wherein the first, second, and third wavelengths are red, green, and blue.

8. The system of claim 1, wherein the color filter further comprises a third segment capable of transmitting the third and fourth wavelengths.

9. The system of claim 8, wherein the first wavelength is a fourth wavelength that is yellow.

10. A digital display system, comprising:

a fluorescent member configured to generate light having a first wavelength, a second wavelength, and a third wavelength;

a color filter configured to receive light from the fluorescent member, the color filter having:

a first segment configured to transmit the light having the first wavelength and reflect the light having the second wavelength toward the fluorescent member,

a second segment configured to transmit the light having the second wavelength and reflect the light having the first wavelength toward the fluorescent member,

wherein the fluorescent member is configured to reflect the reflected light having the first color toward the color filter and to reflect the reflected light having the second color toward the color filter.

11. The digital display system of claim 10, wherein the color filter has an involute color structure.

12. The digital display system of claim 10, wherein the color filter is a static color filter.

13. The digital display system of claim 12, wherein the static color filter has the first segments and the second segments alternating in a checkerboard pattern.

14. The digital display system of claim 10, further comprising an illumination source configured to emit light of a wavelength directed toward the fluorescent member.

15. The system of claim 12, wherein the fluorescent member is a static fluorescent component.

16. A method, comprising:

receiving blue light by the fluorescent member;

converting at least a portion of the blue light to yellow light by the fluorescent member, the yellow light comprising red and green light;

reflecting at least a portion of the blue light by the fluorescent member.

Directing at least a portion of the blue light to a color filter;

directing at least a portion of the yellow light to the color filter;

transmitting the red light and the blue light through a first segment of the color filter;

transmitting the green light and the blue light through a second segment of the color filter;

reflecting the green light from the first segment of the color filter;

reflecting the red light from the second segment of the color filter;

recycling the reflected green and red light as reflected light by reflection;

directing the reflected light towards the color filter; and

transmitting a portion of the recycled reflected light through the first segment and the second segment of the color filter.

17. The method of claim 16, wherein the step of recycling the light is performed by an integrator rod.

18. The method of claim 16, further comprising transmitting yellow and blue light through the third segment of the color filter.

19. The method of claim 18, wherein the red light, the green light, the blue light, and the yellow light are transmitted to a display simultaneously.