Method of forming a burner assembly
A method of forming a burner assembly includes capturing at least one feature of a burner with an imaging system, determining a location of a fireball based on the feature, moving the burner to an aligned position relative to a header or reflector based on the location of the fireball, and securing the burner in the aligned position.
This application is related to “Method of Forming a Lamp Assembly”, by Jimmy Perez et al., Attorney Docket No. 200407967-1, which is filed concurrently with this application.
BACKGROUNDDigital projectors, such as digital micro-mirror devices (DMD) and liquid crystal device (LCD) projectors, project high quality images onto a viewing surface. Both DMD and LCD projectors utilize high intensity lamps and reflectors to generate the light needed for projection. Light generated by the lamp is concentrated as a “fireball” that is located at a focal point of a reflector. Light produced by the fireball is directed into a projection assembly that produces images and utilizes the generated light to illuminate the image. The image is then projected onto a viewing surface. Misalignment of the focal point causes degradation of the image since less light is captured and creates “hot spots” on the screen instead of a uniform brightness.
Efforts have been directed at making projectors more compact while making the image of higher and better quality. As a result, the lamps utilized have become more compact and of higher intensity. Higher intensity lamps produce high, even extreme heat. The outer surface of the lamps can approach temperatures of 900 degrees C. As a result, projector designs must account for the intense heat. In addition, losses due to misalignment of the fireball with respect to the reflector are amplified in systems utilizing high intensity lamps.
Some methods of aligning the fireball with respect to the reflector include lighting the burner until the burner reaches its operating temperature. Thereafter, the burner is moved relative to the reflector to place the burner as near as possible to the focal point of the reflector and thereby maximize the light output of the lamp assembly. The burner is moved relative to the reflector until the light output of the lamp assembly is at an acceptable level. Such an approach may be time consuming.
SUMMARYA method of forming a burner assembly includes capturing at least one feature of a burner with an imaging system, determining a location of a fireball based on the feature, moving the burner to an aligned position relative to a reference point based on the location of the fireball, and securing the burner in the aligned position.
BRIEF DESCRIPTION OF THE DRAWINGSThe accompanying drawings illustrate various embodiments of the present apparatus and method and are a part of the specification. The illustrated embodiments are merely examples of the present apparatus and method and do not limit the scope of the disclosure.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.
DETAILED DESCRIPTIONA method and system is provided herein for forming a lamp assembly for use in a display system. The lamp assembly according to one exemplary embodiment includes a burner, a reflector, and a header. The burner generates light, which is then directed by a reflector to a light modulator assembly. The percentage of light generated by the burner that is directed to the light modulator assembly is dependent, at least in part, on the alignment and orientation of the burner relative to the reflector. According to one exemplary embodiment, the alignment of the burner relative to the reflector may be controlled by aligning the burner relative to a header that has surfaces that are aligned relative to the reflector.
According to one exemplary embodiment, the features of the burner may be identified. These features may then be analyzed to determine the proper position and orientation of the burner relative to the header. Thereafter, the header and burner may be oriented, aligned, and secured in a specific position. An exemplary system, which will be discussed in more detail below, makes use of optical components and a processor to perform the alignment and orientation process. An exemplary display system will first be discussed, followed by a discussion of an exemplary burner assembly, a method of forming a burner assembly, and a system for aligning a burner and a header.
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present method and apparatus. It will be apparent, however, to one skilled in the art that the present method and apparatus may be practiced without these specific details. Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearance of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
Display System
In particular, the burner assembly (120) includes a burner (140) coupled to a header (145). The header (145) provides support and alignment for the burner (140) relative to the reflector (125). According to the present exemplary embodiment, the header (145) also allows the burner assembly (120) to be removably coupled to the reflector (125). As a result, when the burner (140) has surpassed its useful life, the burner assembly (120) may be replaced without replacing the entire lamp assembly (117).
The burner (140) may be precisely aligned relative to the header (145) using a visual alignment process while the burner (140) is not in operation. As a result, the center of the burner (140) may be precisely aligned relative to the header (145). The reflector (125) is configured to receive the burner assembly (120). In addition, the reflector is configured to have the header (145) placed into aligned contact therewith.
The alignment of the burner (140) relative to the header (145) and the alignment of the header (145) relative to the reflector (125) provides for alignment of the burner (140) relative to the reflector (125). More specifically, according to one exemplary embodiment, the burner (140) generates concentrated light, referred to as a fireball, in a central portion (150) thereof. By aligning the fireball with the focal point of the reflector (125), the amount of light generated by the lamp assembly (117) may be optimized. An exemplary burner assembly, including features used by an exemplary system and method of aligning a burner relative to the header will now be discussed in more detail.
Burner Assembly
A voltage differential may be created at the opposing electrodes in the burner (202). This voltage differential creates a fireball in the central portion (210) of the burner (202). In the case of an ultra-high pressure (UHP) burner, the central portion of the glass tube (205) is filled with mercury vapor or other vapor that results in the generation of a plasma caused by an arc across the first and second electrodes (215, 220).
The location of the arc between the first and second electrodes (215, 220) may vary as the burner assembly (200) is heated and reaches a steady operating temperature. Thus, the location of the arc, or the fireball, may cause the location of the fireball to vary from the center of the central portion (210) of the burner (202).
The burner assembly (200) according to the one exemplary embodiment includes a header (235) with at least one reference point or surface. For ease of reference, a reference surface such as a first surface (240) or other surface on the header (235) will be discussed. Further, a reference surface may be found on a fixture holding the burner or any other point with a known location.
The first surface (240) may then be aligned relative to a surface on the reflector (125;
A longitudinal axis (245) may be defined along the length of the burner assembly (200). According to one exemplary embodiment, the first and second electrodes (215, 220) may lie on the longitudinal axis (245). For ease of reference, each feature will be referred to as being viewed in profile along the longitudinal axis (245). When thus viewed, first and second opposing edges (250, 255) of the central portion (210) of the glass tube (205) may be identified. The gap (225) between the first and second electrodes (215, 220) may also be identified. In particular, the tip of the first electrode (215) may be identified as well as the tip of the second electrode (220). The distance between these tips defines the gap (225) between the electrodes (215, 220). As previously discussed, the location of the gap (225) may be used in the identification of the fireball. In particular, the location of the fireball may be established relative to a point or surface while the burner is activated. Such points or surfaces may include points or surfaces on a header. As the burner cools, the burner remains fixed relative to the points or surface on the header. Thus, the location of these features when the burner relative to the header may be correlated to the location of the fireball when the burner is in operation.
Further, other features of the electrodes may be identified. For example, first and second edges (270, 275) and the first electrode (215) may be identified. In addition, coils (280) may be wrapped around the first electrode (215). These coils (280) may also be identified.
In addition to features on the first and second electrodes (215, 220), any number of other features, such as first and second leads (285, 290) coupled to the first and second electrodes (215, 220 respectively) or other features may also be identified. These features will now be discussed with reference to an alignment process.
Method of Forming a Burner Assembly
The present exemplary method begins by determining the optimal position of a representative burner relative to a representative reflector (step 300). The determination of the optimal position of the burner relative to a representative reflector may be performed a single time. Thereafter, the subsequent steps of the process may be performed while the burner is cold. According to one exemplary method, the optimal position of representative burner relative to a header may be directly measured. According to such a process, a representative burner is coupled to a representative reflector. The relative position of the burner is then varied with respect to the reflector until a maximum value is obtained, thereby providing a location and orientation of the burner relative to the reflector that maximizes the amount of light generated by the burner that is directed out of the reflector.
Thereafter, the burner may be inactivated and allow to cool. At such a position, a header may then be tacked into place while the burner is maintained in its aligned position relative to the reflector to form an exemplary burner assembly. The header is tacked to the burner such that the position of the burner relative to the reflector is known. Thus, the location of the header corresponds to a known location. The burner assembly may then be removed and the location of the features of the burner relative to the header may be measured. These locations may then be recorded for later use. For example, the features of these burners may then be measured to determine the relative location of burner features to the reference point. More specifically, while the burner is hot and aligned relative to the reflector, the fireball is located at the focal point of the reflector. The position of the burner relative to a known point is known. This position may be referred to as an aligned position. While the burner cools, it remains at a substantially fixed location relative to the known point. Once the burner is cooled, the features of the burner and their position relative to the known point may be captured. Since the location of the burner relative to the known point has remained substantially unchanged, the location of the features relative to the known point provides an indication of the location of the fireball when the burner is hot. When features of an individual feature are captured, a known point or surface may be placed a substantially similar position, such that the features of the burner are at an aligned position relative to the known point. With the burner at such a position, the location of the fireball may be estimated, based on the aligned position. Further, the reflector to which the burner assembly is to be aligned may be substantially similar to the representative reflector. In particular, the reflector may include a datum structure that provides a known location and orientation relative to the focal point of the reflector. By placing the header into contact with the reflector, burner is placed in a substantially similar the and location relative to the reflector as that established with a representative burner and reflector. Thus, knowledge of the location of features relative to a reference surface may be used to extrapolate the location of the fireball of a burner relative to the header without firing the burner. While one set of features has been discussed above, any number of burners may be obtained with any number of visual features that may be measured and analyzed.
Once the location of the features has been determined, these locations may be X, Y, and Z alignment settings. Accordingly, the output of a representative lamp may be optimized and the corresponding position of the burner and its features relative to a header may be determined. In particular, the orientation and position defined by six degrees of freedom may be constrained. For example, according to one coordinate system, these six degrees of freedom may include rotation or orientation of the burner relative to X, Y, and Z axes and translation parallel to the X, Y, and Z axes. For ease of reference, an X, Y, and Z coordinate system will be referenced below.
Further, according to another exemplary method, several burner assemblies may be constructed in which the orientation and alignment of each of the burners relative to a corresponding header is known and is varied from burner assembly to burner assembly by a controlled amount. Thereafter, each burner assembly may be coupled to a reflector and fired. The output of each burner assembly may then be recorded and analyzed to determine which burner assembly(ies) has suitable light output characteristics.
The features of these burner assemblies may then be measured to determine the relative location of burner features to header surfaces.
As previously discussed, once the optimal position of the burner has been determined relative to the header, the subsequent processes may be performed while each burner is cold. According to the present exemplary embodiment, a burner may be coupled to a burner fixture (step 310). In particular, the burner may be placed in the fixture such that the fixture is able to rotate about three degrees of freedom to control the orientation of the burner relative to the header. For example, the fixture may be configured to control movement of the burner and/or the header through all six degrees of freedom as previously discussed. Further, the burner may be placed in the fixture such that a longitudinal axis of the burner is visible from two or more orthogonal views.
Thereafter, according to the present exemplary embodiment, a header may be coupled to a reference fixture assembly (step 320). The placement of the header into the reference fixture assembly may include placing the header into a known position relative to the fixture such that the location and alignment of any number of features on the header are known. For example, a front surface of the header may be placed against a corresponding surface on the fixture, such that the location of the front surface is known. In the case where the burner is aligned directly to a reflector, the reflector would be placed in the reference fixture assembly. The reference fixture assembly may be able to translate through three degrees of freedom, thereby allowing the header to be coupled to the burner at a known location.
The features of the burner are then imaged (step 330). In particular, the features of the burner may be acquired by a vision system. For example, a vision system may be arranged relative to the burner such that the lamp is able to view the burner from two orthogonal perspectives, both of which profile the longitudinal axis of the burner. By capturing a plurality of orthogonal views, the system is able to accurately determine the location and orientation of the burner in three-dimensions. In particular, by capturing a first orthogonal view, the orientation and position of the burner may be known in a first plane. Thereafter, by capturing a second orthogonal view, the orientation and position of the burner may be further known in a second plane. When the orientation and position of the burner are known in two orthogonal planes, such as by capturing two orthogonal views that are normal to each other, the position of the burner is known in three dimensions.
According to one exemplary method, the edges of a glass tube may be first located in the image. If the edges are found, the area of the image outside of the edges may be eliminated from further consideration. Eliminating the rest of the image from consideration may reduce subsequent imaging and/or computational requirements by reducing the area to be analyzed. As a result, eliminating the image beyond the edges of the glass tube may speed up subsequent steps of the process. The process may be performed regardless of whether the edges of the glass tube are found.
Accordingly, once the edges of the tube have been found or it has been determined that they will not be found, any other possible features of the correct size, shape, and/or intensity are located in the image. Such features may include, but are not limited to, the electrodes, coils, filament, and shape of the central portion of the glass tube. Logic is then applied to the measurements to eliminate spurious noise features. For example, a measured distortion to the shape of an electrode may be more likely mercury or other material within the glass tube than non-uniformity of the electrode itself and may be filtered out.
Next, the process interpolates the measurements to determine the location of the fireball (peak light intensity) of the lamp (step 340). The location data is then used for motion control to position the burner and/or the header (step 350). This position may be based on the results determined above correlating the location and alignment of the parts to each other with the light/power output produced as the result of such alignment. For example, as previously discussed, the location of a reference point or surface, such as a representative header, may be established relative to the fireball at the focal point of a representative reflector. Thereafter, the features of the representative burner may be captured relative to the representative header. Thus, a representative aligned relationship between the representative features and the representative header may be established. When the features of an individual burner are captured, a header may be similarly aligned and oriented to place the features and the header in an aligned position, similar to the representative aligned position introduced.
The burner may then be tacked into correct position relative to the header (step 360). Tacking may include the placement of relatively small amounts of adhesive sufficient to secure the alignment of the burner relative to the header. Once the correct position is secured by the tacking process, the burner assembly may be removed from the fixtures and further secured using ceramic cement or other materials (step 370), which are then cured.
As introduced, once the output of a representative burner and reflector have been established, steps 310 through 370 may be performed for such representative burners without directly measuring the position of the burner relative to the reflector while the burner is heated to an operating temperature. Thus, the burner may be aligned relative to a reference point or surface, such as points or surfaces on a header or directly to a reflector using an optical system while the burner is cool. One exemplary alignment system will now be discussed in more detail.
Alignment System
The first and second light sources (415, 420) may include any suitable light source. For example, suitable light sources include, without limitation, a white light or a coherent light source. The light sources may also include a filter to remove undesired light wavelengths (e.g., a low-pass, high-pass, or band-pass filter); a polarizer to alter the polarization state of the light; and/or other components commonly used in image processing. Further, the first and second light sources (415, 420) may be replaced with radiation sources for use in x-ray imaging systems. The first and second light sources (415, 420) according to the present exemplary embodiment illuminate the burner (202) and/or the header (235).
For example, according to one exemplary embodiment, the first and second light sources (415, 420) are oriented to provide rear illumination for the first and second imaging devices (405, 410). This rear illumination may enhance the ability of the system to detect features. In particular, as light from the rear is incident on the features, the features direct light away while non-reflected light is directed to the first and second imaging devices (405, 410). As a result, the features appear dark relative to the first and second light sources (415, 420). These images containing these features are first captured by the first and second imaging devices (405, 410).
The first imaging device (405) is oriented substantially normal to the longitudinal axis of the burner (202). Consequently, the first imaging device (405) is configured to capture a first orthogonal profile view of the burner (202) along the longitudinal axis of the burner (202). The first imaging device (405) may be any suitable imaging device capable of capturing images. For example, according to one exemplary embodiment, the first imaging device (405) includes a digital camera, such as a device utilizing charge couple devices (CCDs) to capture the image. According to such an embodiment, the imaging device converts light incident thereon to signals. These signals are then conveyed to the processor (435).
The first imaging device (405) may be mounted at a known distance from the burner, such as by mounting the first imaging device (405) on an extension tube or other appropriate apparatus to provide appropriate focal distance and depth. Any desired magnification optics (437) may be included in this portion of the optical path. In the case that the magnification optics (437) are variable, they may also be coupled to the processor (435). In one exemplary embodiment the optical path including focus, distance to image, and magnification may be pre-set. In other exemplary embodiments, it may be desirable to focus on a subsection of a lamp. In such embodiments, the magnification optics (437) may include an adjustable zoom and focus control with corresponding motor control. According to other exemplary embodiments, the first imaging device (405) may include an x-ray device and/or a thermal sensor.
The second imaging device (410) also captures features of the burner (202) from a second orthogonal view. In particular, the second imaging device (410) may be placed directly in the path of the light or the second imaging device may be placed in optical communication with a mirror (440) such as a periscope mirror or turning mirror. The mirror (440) is located orthogonally from the first camera, such that a second orthogonal view is incident on the mirror.
The mirror (440) is oriented to direct the second orthogonal view to the second imaging device (410). Accordingly, the mirror (440) allows the second imaging device (410) to capture a second orthogonal profile view of the burner (202). The second imaging device (410) may be any suitable imaging device capable of capturing images. For example, according to one exemplary embodiment, the second imaging device (410) includes a digital camera as described above, which converts light to electrical signals and directs the signals to the processor (435). The second imaging device (410) may also be mounted at a fixed distance as described above. Further, magnification optics (437) may also be optically coupled to the second imaging device (410) as desired. According to other exemplary embodiments, the first imaging device (405) may include an x-ray device and/or a thermal sensor.
The images captured by the first and second imaging devices (405, 410) are converted to electrical signals and sent to the processor (435). The processor (435) processes the signals and analyzes the processed signals for the presence of one or more features. For example, according to one exemplary embodiment, the processor (435) includes an image processing module (445) residing thereon. The image processing module (445) may be designed to analyze images of representative burners. Such an image processing module (445) may be configured to automatically identify and measure the location of distinguishable features. Further, the image processing module (445) may be configured to calculate the proper orientation and position of the burner (202) relative to the header (235). According to the present exemplary embodiment, the image processing module may include a digital storage medium for recording of images and results, and a user interface for inputting commands and viewing images and/or results.
The processor (435) may also include a movement control module (450). The movement control module (450) uses the output of the imaging processing software to generate controls for the burner fixture assembly (425) and the reference fixture assembly (430). For ease of reference, a coordinate system will be referenced in which the longitudinal axis lies along the Z-axis as shown in
The movement control module (450) may also control the translation of the reference fixture assembly (430). In particular, movement control module (450) controls the movement of a robotic arm (not shown), which is coupled to the reference fixture assembly (430). This movement may include the translation of the robotic arm, and thus the reference fixture assembly (430), parallel to each of the X, Y, and Z axes. The header (235) may be coupled to the reference fixture assembly (430) in a known alignment. In particular, a first surface (240;
Accordingly, the movement control module (450) is able to convert positional information provided by the image processing module (445) to control movements of the burner fixture assembly (425) and the reference fixture assembly (430) to thereby control the orientation and movement of the burner (202;
In conclusion, a method and system have been described herein for forming a burner assembly for use in a display system. The burner assembly according to one exemplary embodiment includes a burner and a header. The burner generates light, which is then directed by a reflector to a light modulator assembly. The percentage of light generated by the burner that is directed to the light modulator assembly is dependent, at least in part, on the alignment and orientation of the burner relative to the reflector. According to one exemplary embodiment, the alignment of the burner relative to the reflector may be controlled by aligning the burner relative to a header that has surfaces that are aligned relative to the reflector.
The preceding description has been presented only to illustrate and describe the present method and apparatus. It is not intended to be exhaustive or to limit the disclosure to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the disclosure be defined by the following claims.
Claims
1. A method of forming a burner assembly, comprising:
- capturing at least one feature of a burner with an imaging system;
- determining a location of a fireball based on said at least one feature;
- moving said burner to an aligned position relative to a reference point based on said location of said fireball; and
- securing said burner in said aligned position.
2. The method of claim 1, wherein capturing said at least one feature includes identifying at least one of a feature of a glass tube of said burner, a feature of an electrode, a gap between electrodes, and a shape of a central portion of said burner.
3. The method of claim 1, wherein determining a location of said fireball includes capturing a plurality of profile views of said burner.
4. The method of claim 3, wherein capturing said plurality of profile view includes capturing a plurality of orthogonal profile views of said burner.
5. The method of claim 3, wherein capturing a plurality of profile views of said burner includes capturing images with first and second imaging devices.
6. The method of claim 5, wherein said capturing said images with said first and second imaging devices includes at least one of capturing an optical image, capturing an x-ray image, and capturing a thermal image.
7. The method of claim 5, wherein capturing image with said first and second imaging devices includes capturing a first orthogonal view of said burner and capturing a second orthogonal view directed to said second imaging device by a mirror.
8. The method of claim 5, and further comprising providing rear illumination for each of said first and second imaging devices.
9. The method of claim 1, and further comprising the step of determining a proper location of said burner relative to a reflector.
10. The method of claim 1, wherein securing said burner to said header includes tacking said burner to said header with an adhesive.
11. The method of claim 1, wherein moving said header to an aligned position relative to burner includes controlling an orientation of said burner by rotating said burner relative to three axes and translating said header parallel to said three axes.
12. The method of claim 11, wherein rotating said burner relative to said three axes includes controlling a fixture, a Goniometer, and a rotational stage and translating said header comprises translating a reference fixture assembly coupled to a robotic arm.
13. A system for forming a burner assembly, comprising:
- a burner fixture assembly;
- a reference fixture assembly,
- a first imaging device, said first imaging device being configured to capture a first profile view of a burner;
- a second imaging device, said second imaging device being configured to capture a second profile view of said burner; and
- a processor coupled to said first imaging device and said second imaging device, said processor being configured to estimate a location of a fireball based on said first and second views.
14. The system of claim 13, wherein said processor is configured to estimate a location of a fireball of a burner based on features identified in said first and second views.
15. The system of claim 13, wherein said processor is configured to calculate an alignment and orientation a header relative to said burner based on said location of said fireball.
16. The system of claim 13, wherein said processor is configured to control movements of said burner fixture assembly and said reference fixture assembly to align said header relative to said burner.
17. The system of claim 13, wherein said burner fixture assembly includes a rotational fixture, a Goniometer, and a rotational stage.
18. The system of claim 13, and further comprising a mirror configured to direct light from said burner to said second imaging device.
19. The system of claim 13, wherein said processor includes an image processing module and a movement control module.
20. The system of claim 13, and further comprising a first and second light sources, said first and second light sources being configured to provide rear illumination for said first and second imaging devices.
21. The system of claim 13, wherein said first and second imaging devices include at least two of a group include an optical imaging device, an x-ray image device, and a thermal imaging device.
22. A system, comprising:
- means for capturing an image of a burner;
- means for identifying at least one feature of said burner in said image; and
- means for determining an alignment and orientation of said burner relative to a header based on said at least one feature.
23. The system of claim 22, and further comprising means for moving said header and burner based on said alignment and orientation.
24. The system of claim 22, and further comprising means for illuminating said burner.
25. A method of forming a lamp assembly, comprising:
- placing a fireball of a representative burner near a focal point of a representative reflector;
- placing a representative surface at a known location relative to said burner;
- capturing features of said representative burner;
- establishing a position and orientation of said representative surface relative to said features; said position and orientation comprising a representative alignment;
- capturing features of an individual burner; and
- aligning said individual burner to an individual surface in a position and orientation corresponding to said representative alignment while said burner is in a non-operating state.
26. The method of claim 25, wherein aligning said individual burner to said individual surface includes aligning said individual burner to a header.
27. The method of claim 25, wherein capturing features of said individual burner includes performing an imaging operation.
28. The method of claim 25, and further comprising securing said individual burner to said individual burner.
Type: Application
Filed: Aug 30, 2005
Publication Date: Mar 1, 2007
Inventors: Tim Bartel (Salem, OR), Jimmy Perez (Corvallis, OR), Kenneth Coykendall (Corvallis, OR), John Lee (Sweet Home, OR), David Huhn (Monmouth, OR), Andrew Lovvorn (Albany, OR), Robert Sattem (Albany, OR)
Application Number: 11/215,962
International Classification: F23N 5/00 (20060101); F23D 11/36 (20060101);
