Abstract:
A light source adjusting module for processing a beam of light projected from a light source. The light source adjusting module comprises a sleeve, a first optical element, a first holder for carrying the first optical element, a second optical element, a second holder for carrying the second optical element, a first adjusting member, a second adjusting member and a sleeve-adjusting member. The position of the first optical element can be adjusted through the first adjusting member and the position of the second optical element can be adjusted through the second adjusting member. Furthermore, the angle of the rotatable sleeve can be set through the sleeve-adjusting member. A beam projected from a light source can be adjusted to meet a specific design requirement after appropriately setting the adjustable members within the light source adjusting module.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the priority benefit of Taiwan application serial no. 93104200, filed Feb. 20, 2004.  
       BACKGROUND OF INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a light source module. More particularly, the present invention relates to a light source adjusting module.  
         [0004]     2. Description of the Related Art  
         [0005]     In recent years, liquid crystal displays have been widely adopted in many electrical appliances including televisions, portable computers and projectors. In general, the optical system inside a liquid crystal projector may be an off-axial design or an on-axial design. The incident light and the output light source in an off-axial optical system are on different planes. On the other hand, the incident light source and the output light source in an on-axial optical system are on the same plane. Furthermore, according to the type of projection, a liquid crystal projector can be divided into the front-projecting type and the rear-projecting type. At present, most liquid crystal projectors adopt rear-projecting and on-axial design. In the design and fabrication of liquid crystal projector, the main concerns are the projection quality as well as the size and weight of the optical system within the projector.  
         [0006]     The light source module of most projectors has a light source that provides a light beam through a rod integrator before traveling to the lens so that the lens can focus to produce an image on a designated location. However, without any adjusting mechanism within the light source module, the projector cannot provide suitable focusing adjustment or projecting area adjustments when the projector is placed in a different environment. In other words, a clear projection is only obtained if we apply certain restrictions to the servicing environment. Hence, the provision of some adjusting mechanisms inside the light source module of the projector is sure to increase the clarity of images and relax some of the environmental restrictions.  
         [0007]     Adjustable lens modules have been widely adopted in many types of optical products including cameras and lens systems. For example, U.S. Pat. No. 3,951,522 disclosed a movable camera lens module. The adjustable camera lens module comprises a holder for carrying a lens. Furthermore, a pair of sleeves is disposed on the exterior surface of the holder so that the outer sleeve may rotate. Through a guiding pin on the holder and a guiding groove on the pair of sleeves, the lens is free to move along the main optical axis and change the focusing point of light so that the focal point of the camera lens can be set accordingly.  
         [0008]     Although the aforementioned adjusting mechanism has been used in cameras, none has been applied to a projector so far. Furthermore, with the miniaturization of projectors, the amount of movement permitted by the lens in the light source module is severely restricted. Thus, even if the aforementioned disclosed patent is applied to a projector, moving the lens alone may still not provide the sufficient window of adjustment needed to refocus an incident light beam or change the size of projection area.  
       SUMMARY OF INVENTION  
       [0009]     Accordingly, the present invention is directed to a light source adjusting module capable of adjusting the distance between an incident light beam and lenses for forming an image.  
         [0010]     The present invention is also directed to a light source adjusting module capable of adjusting the position of lenses to change the focus point of a light beam.  
         [0011]     The present invention is also directed to a light source adjusting module capable of rotating a projected image.  
         [0012]     According to an embodiment of the present invention, the light source adjusting module is provided. The light source adjusting module comprises a sleeve having first and second grooves on its surface, a first optical element disposed inside the sleeve having an incident surface and an output surface, a second optical element disposed on an optical path of the light beam behind the first optical element, a first adjusting member contacted to the first optical element through said first groove of the sleeve, a second holder disposed inside the sleeve for carrying the second optical element and a second adjusting member mounted to the second holder through second groove of the sleeve so that the second holder and the second optical element can be moved relative to the sleeve by moving the second adjusting member. Wherein a light beam enters the first optical element through the incident surface and emerges from the output surface of the first optical element. Moreover, the first optical element can be moved relative to the sleeve by moving the first adjusting member.  
         [0013]     According to an embodiment of the present invention, the second holder can be moved horizontally inside the sleeve by moving the second adjusting member within the second groove, and the second holder comprises a cylinder disposed and overlapped to later part of the first holder.  
         [0014]     According to an embodiment of the present invention, the light source adjusting module further comprises a first holder disposed inside the sleeve for carrying the first optical element and a first adjusting member mounted to the first holder through said first groove of the sleeve. Wherein the first holder and the first optical element can be moved relative to the sleeve by moving the first adjusting member.  
         [0015]     According to an embodiment of the present invention, the light source adjusting module further comprises a reflecting plate disposed at one end of the first holder over the incident surface of the first optical element, and the reflecting plate has an opening that exposes at least a portion of the incident surface of the first optical element so that any interfering background light is filtered off.  
         [0016]     According to an embodiment of the present invention, the first holder can be moved horizontally inside the sleeve by moving the first adjusting member within the first groove.  
         [0017]     According to an embodiment of the present invention, the first holder can be rotated relative to the sleeve by moving the first adjusting member within the first groove.  
         [0018]     According to an embodiment of the present invention, the module further comprises a sleeve-adjusting member mounted to the sleeve through third groove so that the sleeve can be moveable relative to the first sleeve ring.  
         [0019]     According to an embodiment of the present invention, the module further comprises an elastic element disposed over the outer surface of the first holder and a second sleeve ring disposed over the first holder and the elastic element mounted to the sleeve. The second sleeve ring to stop the elastic element from forcing the first holder away from the sleeve.  
         [0020]     According to an embodiment of the present invention, the first optical element may be a rod integrator, and the second optical element is, for example, at least one lens.  
         [0021]     According to an embodiment of the present invention, a second type of light source adjusting module for processing a light beam from a light source is provided. The light source adjusting module comprises a sleeve having a first and second grooves on its surface, a first optical element disposed inside the sleeve having an incident surface and an output surface, a second optical element disposed along an optical path of the light beam behind the second optical element, a second holder disposed inside the sleeve for carrying the second optical element and a second adjusting member mounted to the second holder through the second groove. Wherein a light beam enters the first optical element through the incident surface and emerges from the output surface of the first optical element. Moreover, the second holder and the second optical element can be moved relative to the sleeve by moving the second adjusting member.  
         [0022]     According to an embodiment of the present invention, the second holder can be moved horizontally inside the sleeve by moving the second adjusting member within the second groove.  
         [0023]     According to an embodiment of the present invention, the second holder can be rotated relative to the sleeve by moving the second adjusting member within the second groove.  
         [0024]     According to an embodiment of the present invention, the second holder comprises a cylinder disposed and overlapped to later part of the first holder.  
         [0025]     According to an embodiment of the present invention, the module further comprises a reflecting plate disposed along the optical path of a light beam entering the first optical element, and the reflecting plate has an opening that exposes at least a portion of the incident surface of the first optical element so that only the light passing through the opening enters the first optical element.  
         [0026]     According to an embodiment of the present invention, the module further comprises a sleeve-adjusting member contacted to the sleeve for directly rotating the sleeve. Wherein the module further comprises a first sleeve ring disposed over the sleeve and the first sleeve ring has a third groove such that the sleeve can be rotated by moving the sleeve-adjusting member within the third groove.  
         [0027]     According to an embodiment of the present invention, the first optical element comprises a rod integrator.  
         [0028]     According to an embodiment of the present invention, the second optical element comprises at least one lens.  
         [0029]     According to an embodiment of the present invention, a third type of light source adjusting module for processing a light beam from a light source is provided. The light source adjusting module comprises a sleeve, a first optical element disposed inside the sleeve having an incident surface and an output surface, a second optical element disposed on an optical path of the light beam behind the first optical element, a first sleeve ring disposed over the sleeve g having a third groove and a sleeve-adjusting member contacted to the sleeve through the third groove. Wherein a light beam enters the first optical element through the incident surface and emerges from the output surface of the first optical element. Moreover, the sleeve can be moved relative to the first and second optical element by moving the sleeve-adjusting member within the third groove.  
         [0030]     According to an embodiment of the present invention, the module further comprises a reflecting plate disposed along the optical path of a light beam entering the first optical element, and the reflecting plate has an opening that exposes at least a portion of the incident surface of the first optical element so that only the light passing through the opening enters the first optical element.  
         [0031]     According to an embodiment of the present invention, the surface of the sleeve having a first groove and the module further comprises a first holder disposed inside the sleeve for carrying the first optical element and a first adjusting member disposed on the sleeve. Wherein the adjusting member passes through the first groove and connects to the first holder so that the first holder can be moved relative to the sleeve by moving the first adjusting member within the first groove.  
         [0032]     According to an embodiment of the present invention, the first holder can be moved horizontally inside the sleeve by moving the first adjusting member within the first groove.  
         [0033]     According to an embodiment of the present invention, the first holder can be rotated relative to the sleeve by moving the first adjusting member within the first groove.  
         [0034]     According to an embodiment of the present invention, the module further comprises an elastic element disposed within the axial gap on the outer surface of the first holder and a second sleeve ring disposed over the first holder and contacted to the sleeve. The second sleeve ring is used to stop the elastic element from forcing the first holder away from the sleeve.  
         [0035]     According to an embodiment of the present invention, the first optical element may be a rod integrator, and the second optical element is, for example, at least one lens.  
         [0036]     According to an embodiment of the present invention, a fourth type of light source adjusting module for processing a light beam from a light source is provided. The light source adjusting module comprises a sleeve having a first and second grooves on its surface, a first optical element having an incident surface and an output surface, a second optical element disposed on an optical path of the light beam behind the first optical element, a first adjusting member contacted to the first optical element through said first groove of the sleeve, a second holder disposed inside the sleeve for carrying the second optical element, a second adjusting member mounted to the second holder through second groove of the sleeve and a sleeve-adjusting member contacted to the sleeve for directly moving the sleeve. Wherein a light beam enters the first optical element through the incident surface and emerges from the output surface of the first optical element. Furthermore, the first optical element is moved relative to the sleeve by moving the first adjusting member, and the second holder and the second optical element are moved relative to the sleeve by moving the second adjusting member.  
         [0037]     In brief, the present invention utilizes a change in position of the rod integrator and the lens to adjust the clarity of image projection. Furthermore, the angle of an image can be changed through various adjusting members within the adjusting module as well. Hence, the light source adjusting module is able to optimize the brightness and uniformity of a projected image through an adjustment of the adjusting members.  
         [0038]     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0039]     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
         [0040]      FIG. 1A  is a perspective view of a light source adjusting module according to one embodiment of the present invention.  
         [0041]      FIG. 1B  is an exploded view of the light source adjusting module shown in  FIG. 1A .  
         [0042]      FIG. 2  is a top view showing a portion of the light source adjusting module in  FIG. 1A .  
         [0043]      FIG. 3  is a cross-sectional view taken along line I-I′ in  FIG. 2 .  
         [0044]      FIG. 4  is a cross-sectional view taken along line II-II′ in  FIG. 2 .  
         [0045]      FIG. 5  is a cross-sectional view taken along line III-III′ in  FIG. 2 .  
         [0046]      FIG. 6  is a cross-sectional view taken along line IV-IV′ in  FIG. 2 . 
     
    
     DETAILED DESCRIPTION  
       [0047]     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.  
         [0048]      FIG. 1A  is a perspective view of a light source adjusting module according to one embodiment of the present invention.  FIG. 1B  is an exploded view of the light source adjusting module shown in  FIG. 1A . As shown in  FIGS. 1A and 1B , the light source adjusting module  100  mainly comprises a sleeve  105 , a first optical element  110 , a second optical element  111 , a first holder  107 , a second holder  104 , a sleeve-adjusting member  103   a , a second adjusting member  103   b  and a first adjusting member  103   c . The sleeve  105  is disposed on a base  101 . In the present embodiment, the light source adjusting module  100  includes a first adjusting mechanism “a”, a second adjusting mechanism “b” and a third adjusting mechanism “c”. The first adjusting mechanism “a” comprises the first holder  107  and the first adjusting member  103   c . The second adjusting mechanism “b” comprises the second holder  104  and the second adjusting member  103   b . The third adjusting mechanism “c” comprises the sleeve-adjusting member  103   a . In the following, a detailed account of the first, second and third adjusting mechanisms inside the light source adjusting module  100  are described.  
         [0049]      FIG. 2  is a top view showing a portion of the light source adjusting module in  FIG. 1A .  FIG. 3  is a cross-sectional view taken along line I-I′ in  FIG. 2 . As shown in  FIGS. 1A, 2  and  3 , the first optical element  110  is a rod integrator with an incident surface and an output surface for light, for example. Hence, a beam from a light source (not shown) projects onto the incident surface of the first optical element  110  and outputs from the output surface after collimation. The first holder  107  supports the first optical element  110  inside the sleeve  105 . In this embodiment, the first holder  107  is a cylinder that is disposed into the sleeve  105 , for example. The first optical element  110  is disposed into the interior of the cylindrical first holder  107 , for example.  
         [0050]     Although the first optical element  110  is a rod integrator in this embodiment, the first optical element  110  can be some other optical devices including at least one lens. In addition, there is no particular restriction on the design of the first holder  107 . Accordingly, the first holder  107  can be designed to correspond with the type of optical element  110  selected. The first holder  107  is, for example, a semicircular carrier (not shown) for fastening a cylindrical optical element onto a concave semicircular surface.  
         [0051]     The second optical element  111  is a lens, for example. The second holder  104  supports the second optical element  111  inside the sleeve  105 . The second holder  104  is a cylinder that is disposed into the interior of the sleeve  105 , for example. Furthermore, the second optical element  111  is disposed somewhere along the optical path of the light beam behind the first optical element  110 . For example, the second optical element  111  is disposed in front of the output surface of the first optical element  110 . One side of the second optical element  111  is exposed at one end of the sleeve  105  to prevent the interior wall of the sleeve  105  from diffusing the light emerging from the second optical element  111  leading to the projection of a diffused image.  
         [0052]     Obviously, there is no particular restriction on the design of the second holder  104 . The second holder  104  can be some other type of carrier including, for example, a circular holder (not shown). In general, the second optical element  111  is fastened to opening in the middle of the second holder.  
         [0053]     In addition, a reflecting plate may also be installed inside the light source adjusting module  100  along the optical path of a light beam before the light beam enters the first optical element  110  through the incident surface. As shown in  FIGS. 1A, 1B  and  3 , the reflecting plate  109  is disposed at one end of the first holder  107 . The reflecting plate  109  has a rectangular opening  113  that exposes a portion of the incident surface of the first optical element  110 . Hence, light from a light source is able to get into the adjusting module  100  only through the opening  113  so that any interfering background light is filtered off.  
         [0054]      FIG. 4  is a cross-sectional view along line II-II′ in  FIG. 2 . As shown in  FIGS. 2, 3  and  4 , the surface of the sleeve  105  has a groove  114 . The first adjusting member  103   c  passes through the groove  114  and connects to the first holder  107 . The means of locking the first adjusting member  103   c  to the first holder  107  includes a screw, for example. The groove  114  is oriented in a direction parallel to the axis of the sleeve  105  so that the first holder  107  is moved inside the sleeve  105  along an axial direction horizontally by moving the first adjusting member  103   c  inside the groove  114 . Hence, the distance between the first optical element  110  and the second optical element  111  can be adjusted to enhance the brightness and size of a projected image. After moving the first optical element  110  to a suitable position, the first adjusting member  103   c  is screwed so that the position of the first holder  107  between the sleeve  105  is fixed. Furthermore, the surface of the sleeve  105  has a plurality of graduation marks on the edges around the groove  114 . The graduation marks serve as a guide to users in finding out how far the first optical element  110  has moved.  
         [0055]     However, there is no particular limitation in the way the groove  114  is set on the sleeve  105 . Aside from the aforementioned setup, the groove  114  may follow a surface arc of the sleeve  105  so that the first holder  107  is able to move forward axially inside the sleeve  105  and rotate relative to the sleeve  105  at the same time. In this way, the position of the first holder  107  can be finely adjusted.  
         [0056]     It should be noted that although the light source adjusting module has a first adjusting mechanism “a”, a second adjusting mechanism “b” and a third adjusting mechanism “c”, each adjusting mechanism can be independently operated. Hence, in another preferred embodiment, the adjusting mechanism “a” can be used alone in the light source adjusting module (not shown) of the present invention.  
         [0057]      FIG. 5  is a cross-sectional view along line III-III′ in  FIG. 2 . As shown in  FIGS. 2 and 5 , the surface of the sleeve  105  also has another groove  116 . The second adjusting member  103   b  passes through the groove  116  and connects to the second holder  104 . The second adjusting member  103   b  is locked onto the second holder  104  by means of a screw and a threaded-hole assembly, for example. The groove  116  is disposed along a surface arc of the sleeve  105  so that the second holder  104  is moved along the axial direction inside the sleeve  105  and is rotated relative to the sleeve  105  at the same time by moving the second adjusting member  103   b  inside the groove  116 . Hence, the position of the second optical element  111  can be adjusted. In this embodiment, the second optical element  111  is a lens, for example. Therefore, adjusting the position of the second optical element  111  will change the focusing point of a light beam passing out from the second optical element  111  and produce a clearer image.  
         [0058]     After moving the second optical element  111  to a suitable location, the second adjusting member  103   b  is screwed so that the position of the second holder  104  between the sleeve  105  is fixed. Furthermore, the surface of the sleeve  105  has a plurality of graduation marks on the edges around the groove  116 . The graduation marks serve as a guide to users in finding out how far the second optical element  111  has moved.  
         [0059]     Obviously, the groove  116  can also be oriented in a direction parallel to the axis of the sleeve  105  so that the second holder  104  can move horizontally in an axial direction inside the sleeve  105 .  
         [0060]     It should be noted that although the light source adjusting module has a first adjusting mechanism “a”, a second adjusting mechanism “b” and a third adjusting mechanism “c”, each adjusting mechanism can be independently operated. Hence, in another preferred embodiment, the adjusting mechanism “b” can be used alone in the light source adjusting module (not shown) of the present invention or used together with the adjusting mechanism “a” in the light source adjusting module (not shown).  
         [0061]      FIG. 6  is a cross-sectional view along line IV-IV′ in  FIG. 2 . As shown in  FIGS. 3 and 6 , the sleeve-adjusting member  103   a  is contacted to the sleeve  105  for directly rotating the sleeve  105 . The sleeve-adjusting member  103   a  is contacted to the sleeve  105  by means of a screw and threaded-hole assembly, for example. Since rotating the sleeve  105  will also rotate the first holder  107  and the second holder  104  synchronously, the angle of rotation of the opening  113  on the reflecting plate  109  at one end of the first holder  107  can be changed. Through a changing in the rotation angle of the opening  113 , the orientation of a projected image can be adjusted. For example, if a projected image after setting the first optical element  110  and the second optical element  111  to the most suitable positions differs from the vertical position by a counterclockwise tilt of 10°, rotating the sleeve-adjusting member  103   a  clockwise by 10° can correct the tilt.  
         [0062]     In addition, the angle of rotation of the sleeve  105  can be limited to perform a fine adjustment of the projected image.  
         [0063]     Furthermore, as shown in  FIGS. 1B and 2 , the light source adjusting module  100  may further include a sleeve ring  102  on the sleeve  105 . The sleeve ring  102  has a groove  120 , for example. The sleeve-adjusting member  103   a  passes through the groove  120  and connects to the sleeve  105 . The groove  120  is disposed along a tangent direction of the sleeve ring  102  so that the sleeve  105  is rotated by moving the sleeve-adjusting member  103   a  along the groove  120 . The surface of the sleeve ring  102  has a plurality of graduation marks on the edges around the groove  120 . The graduation marks serve as a guide to users in finding out the angle through which the sleeve  105  has rotated.  
         [0064]     It should be noted that although the light source adjusting module has a first adjusting mechanism “a”, a second adjusting mechanism “b” and a third adjusting mechanism “c”, each adjusting mechanism can be independently operated. Hence, in another preferred embodiment, the adjusting mechanism “c” can be used alone in the light source adjusting module (not shown) of the present invention. Alternatively, the adjusting mechanism “c” can be used together with the adjusting mechanism “a” or the adjusting mechanism “b” in the light source adjusting module (not shown). However, putting all the adjusting mechanisms “a”, “b” and “c” together in the same light source adjusting module is the one shown in the figures according to the embodiment of the present invention.  
         [0065]     As shown in  FIG. 3 , the first holder  107  is a cylinder with a variable radius. The first holder  107  has a larger radius in the central portion than each end, for example. Furthermore, the interior of the sleeve  105  has a ring-like protruding member  118 . There is an axial gap between the first holder  107  and the ring-like protruding member  118  so that some movement of the first holder  107  in the axial direction inside the sleeve  105  is permitted. Similarly, there is an axial gap between the second holder  104  and the ring-like protruding member  118  so that some movement of the second holder  104  in the axial direction within the sleeve  105  is permitted.  
         [0066]     To buffer the axial movement of the first holder  107  inside the sleeve  105  so that any damage or shift in position of internal elements caused by a sudden impact of the first holder  107  on the ring-like protruding member  118  of the sleeve  105  is prevented, an elastic element  112  is disposed within the axial gap between the first holder  107  and the ring-like protruding member  118 . The elastic element  112  is a circular spring plate disposed into the first holder  107 , for example.  
         [0067]     An additional sleeve ring  106  is also mounted over the exposed first holder  107  at one end of the sleeve  105 . The sleeve ring  106  is contacted to the sleeve  105  and has a smallest radius smaller than the central portion of the first holder  107 . Here, the variable radius of the first holder  107  is utilized to grip the sleeve ring  106  tightly and prevent the elastic element  112  from forcing the first holder  107  away from the sleeve  105 .  
         [0068]     In summary, the present invention utilizes the change in distance between the two optical elements such as the rod integrator and the lens inside a light source adjusting module to adjust the size and brightness of a projected image and prevent chromatic aberration of images due to external vibrations. In addition, the focusing point can be changed through an adjustment of the lens so that a clearer projected image is obtained. Furthermore, the entire light source adjusting module can be rotated to correct any tilt in the projected image. Therefore, a projected image with the optimal brightness and uniformity is obtained when the light source adjusting module of the present invention is used inside a projector.  
         [0069]     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.