Partially polarized beam splitter for optical systems

Abstract

In certain embodiments, the beam splitter includes a substrate and an internal plane within the substrate. The substrate includes a transparent material and a plurality of surfaces that receive light from the sample and the overlay projector and transmit the light toward the eyepiece and camera. The internal plane includes a central partial reflector and an outer transmissive portion. The central partial reflector directs the light from the sample toward the eyepiece by transmitting a portion of the light, directs the light from the sample toward the camera by reflecting the remaining portion of the light, and directs the light from the overlay projector toward the eyepiece by reflecting the light. The outer transmissive portion directs the light from the sample toward the eyepiece by transmitting the light, and directs the light from the overlay projector toward an aperture that blocks the light by transmitting the light.

Description

Technical Field

[0001] The present disclosure generally relates to an optical beam splitter, and more particularly to a partially polarized beam splitter for an optical system.

Background Art

[0002] An optical system such as a microscope may include optical components that deliver an optical beam from different light sources to different destinations. For example, a microscope may include an eyepiece that enables a user to view a sample, an overlay projector that provides an overlay for a sample image, and a camera that records the sample image. A beam splitter may be used to direct light from the sample and the overlay projector to the camera and / or the eyepiece.

Summary of the Invention

Means for Solving the Problems

[0003] In certain embodiments, the beam splitter includes a substrate and an internal plane within the substrate. The substrate includes a transparent material having a surface that includes an axis and first, second, third, and fourth surfaces. The first surface receives light from the sample, the second surface transmits light to the eyepiece, the third surface receives light from the overlay projector, and the fourth surface transmits light to the camera. The internal plane includes a central partial reflector and an outer transmission portion. The central partial reflector directs light from the sample to the eyepiece by transmitting a portion of the light from the first surface to the second surface, directs light from the sample to the camera by reflecting the remaining portion of the light from the first surface to the fourth surface, and directs light from the overlay projector to the eyepiece by reflecting light from the third surface to the first surface. The outer transmission portion directs light from the sample to the eyepiece by transmitting the light from the first surface to the second surface, and directs light from the overlay projector toward an aperture that blocks the light by transmitting the light from the third surface to the fourth surface.

[0004] Multiple embodiments may not include any of the following features, or may include one, some, or all of the following features.

[0005] *The internal plane is positioned at a 40-50 degree angle to the substrate axis.

[0006] *The central reflective portion essentially has its center at the center of the outer transmissive portion.

[0007] *The central reflective portion is offset from the center of the outer transmissive portion.

[0008] *The central reflective portion has a substantially square shape when viewed from the third surface.

[0009] *The central reflective portion has a substantially circular shape when viewed from the third surface.

[0010] *The central reflective section has a polarizing filter that transmits light with a first polarization and reflects light with a second polarization. Light from the sample has both the first and second polarizations, and light from the overlay projector has the second polarization.

[0011] * The aperture forms an opening that is substantially the same shape as the central reflective portion.

[0012] * The aperture forms an opening up to 20% smaller than the central reflective area.

[0013] In certain embodiments, a method for directing light includes receiving light from a sample and an overlay projector using a beam splitter. The beam splitter has a substrate comprising a transparent material. The substrate has an axis and an internal plane having a central partial reflector and an outer transmissive portion. The substrate includes a first surface for receiving light from the sample, a second surface for transmitting light to an eyepiece, a third surface for receiving light from the overlay projector, and a fourth surface for transmitting light toward a camera. The light from the sample is directed toward the eyepiece by the outer transmissive portion transmitting the light from the first surface to the second surface. The light from the sample is directed toward the eyepiece by the central partial reflector transmitting a portion of the light from the first surface to the second surface. The light from the sample is directed toward the camera by the central partial reflector reflecting the remaining portion of the light from the first surface to the fourth surface. The light from the overlay projector is directed toward an aperture that blocks the light by the outer transmissive portion transmitting the light from the third surface to the fourth surface. The light from the overlay projector is directed towards the eyepiece by the central partial reflector, which reflects the light from the third surface to the first surface.

[0014] Multiple embodiments may not include any of the following features, or may include one, some, or all of the following features.

[0015] *The internal plane is positioned at a 40-50 degree angle to the substrate axis.

[0016] *The central reflective portion essentially has its center at the center of the outer transmissive portion.

[0017] *The central reflective portion is offset from the center of the outer transmissive portion.

[0018] *The method further includes transmitting light having a first polarization through a polarizing filter in the central partial reflector, and reflecting light having a second polarization through the polarizing filter. The light from the sample has both the first and second polarizations, and the light from the overlay projector has the second polarization.

[0019] * The aperture forms an opening that is substantially the same shape as the central reflective portion.

[0020] * The opening forms an opening up to 20% smaller than the central reflective portion.

[0021] In certain embodiments, the beam splitter includes a substrate, an internal plane within the substrate, and an aperture. The substrate includes a transparent material having an axis and a plurality of surfaces, including first, second, third, and fourth surfaces. The first surface receives light from the sample, the second surface transmits light toward the eyepiece, the third surface receives light from the overlay projector, and the fourth surface transmits light toward the camera. The internal plane is positioned at 40 to 50 degrees with respect to the substrate axis and includes a central partial reflector and an outer transmissive portion. The central partial reflector directs light from the sample toward the eyepiece by transmitting a portion of the light from the first surface to the second surface, directs light from the sample toward the camera by reflecting the remaining portion of the light from the first surface to the fourth surface, and directs light from the overlay projector toward the eyepiece by reflecting light from the third surface toward the first surface. The outer transmissive section directs light from the sample towards the eyepiece by transmitting light from the first surface to the second surface, and directs light from the overlay projector towards the light-blocking aperture by transmitting light from the third surface to the fourth surface. The aperture has substantially the same shape as the central partial reflector and forms an aperture up to 20% smaller than the central partial reflector.

[0022] Multiple embodiments may include the following features:

[0023] The central part reflection section has a polarization filter that transmits light having a first polarization and reflects light having a second polarization. The light from the sample has the first polarization and the second polarization, and the light from the overlay projector has the second polarization.

Brief Description of the Drawings

[0024] [Figure 1] An example of a system including a beam splitter that can direct light from different light sources to different destinations according to a specific embodiment is shown. [Figure 2] An example of a beam splitter that can be used in the system of FIG. 1 is shown. [Figure 3A-3B] An example of an internal plane having a central part reflection section and an outer transmission section is shown. [Figure 4] An example of a method performed by the beam splitter of FIG. 1 to direct light from a sample and an overlay projector toward a camera and / or an eyepiece according to a specific embodiment is shown.

Modes for Carrying Out the Invention

[0025] Here, referring to the description and the drawings, exemplary embodiments of the disclosed devices, systems, and methods are shown in detail. The description and the drawings are not intended to be exhaustive or, alternatively, to limit the claims to the specific plurality of embodiments shown in the figures and disclosed in the specification. The drawings represent possible embodiments, but the drawings do not necessarily depend on an exact scale and may simplify, exaggerate, exclude, or partially divide specific features in order to more clearly illustrate the embodiments.

[0026] Optical beam splitters can be used in optical systems such as microscopes to deliver light beams from different light sources to different destinations. In certain microscopes, a beam splitter directs light from a sample towards the camera and eyepiece, and also directs light from an overlay projector towards the eyepiece, so that the user can view the sample with the overlay and the camera can record an image of the sample. For example, a standard aperture-spot beam splitter has a combination of a partially reflective surface, an opaque spot, and an aperture for directing the light. Another example is a standard polarizing beam splitter, which may have a partially reflective polarizing surface and a polarizing filter for directing the light. However, these known beam splitters may not be able to deliver light effectively in certain applications. Therefore, embodiments of beam splitters that deliver light more effectively are described herein.

[0027] According to a particular embodiment, the beam splitter directs light from the sample and the overlay projector toward the eyepiece, and also directs light from the sample toward the camera. The beam splitter includes an internal plane within a transparent material. The internal plane has an outer transmissive portion and a central reflective portion. The outer transmissive portion transmits light from the sample toward the eyepiece. The central partial reflective portion reflects some of the light from the sample toward the camera and transmits the remaining light toward the eyepiece. The central partial reflective portion also reflects light from the overlay projector toward the eyepiece.

[0028] Certain embodiments of the internal plane deliver more light to the eyepiece than known aperture-spot and polarizing beam splitters deliver, and at least the same amount of light to the camera. Furthermore, unlike known aperture-spot beam splitters, the beam splitter described herein utilizes the central ray of light from the overlay projector, resulting in better image quality for both the camera and the projector.

[0029] Figure 1 shows a system 10, which is an example of a system including a beam splitter 20 that can direct light from different light sources to different destinations according to a particular embodiment. In this example, the beam splitter 20 is part of a microscope that includes an overlay projector 22, an eyepiece 24, and a camera 26. The microscope may be used to observe a sample 30. In summary, the beam splitter 20 receives light 32 emitted from or reflected from the sample 30 and directs the light 32 along the light beam path toward the eyepiece 24 and camera 26. The beam splitter 20 also receives light 34 from the overlay projector 22 and directs the light 34 toward the eyepiece 24.

[0030] More specifically, sample 30 may be a body part or tissue of a patient undergoing a diagnostic examination or surgical treatment. For example, sample 30 may be the patient's eye or eye tissue. The overlay projector 22 provides an overlay that is inserted into the light beam path, thereby superimposing the overlay onto the image of sample 30. The overlay projector 22 may be a display that displays the image, such as a liquid crystal display (LCD), such as a liquid crystal on silicon (LCOS) display that generally projects light polarized in only one direction. The overlay may include any appropriate information, such as information describing sample 30 or the treatment for sample 30. For example, this information may describe the patient's eye or the treatment for that eye.

[0031] The eyepiece 24 includes one or more lenses that receive light and present an image to the user. The eyepiece 24 may be an eyepiece, for example, the eyepiece of a microscope. The camera 26 (for example, a digital camera) includes a light sensor that detects light and generates a signal that can be used to generate an image. The camera 26 may display the image via a monitor and / or eyepiece.

[0032] Figure 2 shows an example of a beam splitter 20 that may be used in the system 10 of Figure 1. In this example, the beam splitter 20 is used in conjunction with an aperture 56 that controls the amount of light reaching the camera 26. In general, the beam splitter 20 includes a substrate 36 having an axis 38 and surfaces 40, 42, and an internal plane 44 within the substrate 36. The internal plane 44 has a central partial reflector 50 and an outer transmissive plane 52.

[0033] The beam splitter 20 may have any suitable size and shape. In certain embodiments, the beam splitter 20 is a rectangular box-shaped element (e.g., a cube) with sides in the range of 1 to 10, 10 to 15, 15 to 25, 25 to 30, and / or 30 to 50 millimeters (mm). For example, the beam splitter 20 may be a cube with sides in the range of 15 to 25 mm, for example, 20 mm.

[0034] The substrate 36 includes a transparent material having surfaces 40, 42, such as plastic, glass, or other suitable transparent material. Surfaces 40, 42 include an incident surface 40 (40a, 40b) and an exit surface 42 (42a, 42b). The incident surface 40a receives light from the sample 30, and the incident surface 40b receives light from the overlay projector 22. The exit surface 42a transmits light toward the eyepiece 24, and the exit surface 42b transmits light toward the camera 26. The axis 38 is any suitable imaginary line (typically a line located in the center) that can be used to describe the position of the beam splitter 20. In this example, the axis 38 is the geometric axis of the beam splitter 20 that follows the light beam path from the incident surface 40a to the exit surface 42a.

[0035] The internal plane 44 is a plane within the substrate 36 at any suitable position, such as at an angle of 40 to 50 degrees (e.g., 45 degrees) with respect to the axis 38. The internal plane 44 has a central partial reflecting portion 50 (or "central portion 50") and an outer transmissive portion 52 (or "outer portion 52"). The central portion 50 transmits a portion of the light and reflects the rest. For example, portion 50 may transmit 40% to 60% (e.g., 50%) of the light and reflect the rest. For example, if the light from the sample is not polarized, 50% of the light will be transmitted and 50% will be reflected. The central portion 50 can transmit / reflect light in any suitable way. For example, portion 50 may have a polarizing filter or coating that transmits light of one polarization (e.g., s-polarized) and reflects light of another polarization (e.g., p-polarized). The outer portion 52 transmits light.

[0036] The aperture 56 controls the amount of light reaching the camera 26 by limiting the amount of light passing through the aperture. In certain embodiments, the aperture 56 blocks at least a large portion, if not all, of the light from the overlay projector 22 from reaching the camera 26. In these embodiments, the size and shape of the aperture 56 may form an aperture that is substantially the same as or smaller (e.g., up to 10 or 20 percent smaller) than the aperture of the central portion 50 when viewed from the surfaces 40b, 42b. The smaller the aperture, the better the light can be blocked. In other embodiments, the aperture 56 may be placed between the beam splitter 20 and the overlay projector 22.

[0037] In the example shown in the figure, the overlay projector 22 is an LCOS display that projects p-polarized light 60. The sample 30 reflects p-polarized light 62 and s-polarized light 64. In the example of operation, for the light from sample 30, the central partial reflector 50 directs the light from sample 30 toward the eyepiece 24 by transmitting s-polarized light 64 from surface 40a to surface 42a, and directs the light from sample 30 toward the camera 26 by reflecting p-polarized light 62 from surface 40a to surface 42b. For the light from the overlay projector 22, the central partial reflector 50 directs the light from the overlay projector 22 toward the eyepiece 24 by reflecting p-polarized light 60 from surface 40b to surface 42a. The outer transmissive part 52 directs the light from sample 30 toward the eyepiece 24 by transmitting light (p-polarized light 62 and s-polarized light 64) from surface 40a to surface 42a. The p-polarized light 60 from the overlay projector 22 is transmitted from surface 40b to surface 42b, but the aperture 56 blocks most, if not all, of this light from reaching the camera 26. In other embodiments, one or more polarizers may further polarize the light. For example, polarizers may be placed between the beam splitter 20 and the overlay projector 22 and / or between the beam splitter 20 and the camera 26.

[0038] Figures 3A and 3B show examples of the internal plane 44 (44a, 44b) of the beam splitter 20 of Figure 1, having a central portion 50 (50a, 50b, respectively) and an outer portion 52 (52a, 52b, respectively), as viewed from surfaces 40b, 42b. That is, these examples show portions 50, 52 as if they were projected onto surfaces 40b or 42b. When portions 50, 52 are viewed from an angle of the internal plane 44, they are slightly elongated. In certain embodiments, the outer portion 52 is bounded by the surface of the beam splitter 20, which determines the size and shape of portion 52.

[0039] The central portion 50 may be at any suitable position with respect to the outer transparent portion 52. For example, the central portion 50 is substantially centered at the center 54 of the outer portion 52, which may be where the axis 38 intersects the internal plane 44. In other examples, the central portion 50 may be off-center, or even in contact with an edge of the outer portion 52. In this example, the center of portion 50 may be offset from the center 54 by a distance within the range of 0 to 10, 10 to 30, 30 to 60, and / or more than 60% of the side length of the outer portion 52a. For example, portion 50 may be offset by a distance equivalent to 5% of the side length.

[0040] In addition, the central portion 50 can have any suitable size and shape. In Figure 3A, the central portion 50a is a square of any suitable size. For example, if one side of the outer portion 52a is 15 to 25 mm, for example 20 mm, then one side of the central portion 50a (viewed from the surfaces 40b and 42b) can be 5% to 20%, 20% to 40%, or 40% to 60% of that side, for example 1 to 19 mm, for example 10 mm. In Figure 3B, the central portion 50b is a circle of any suitable size. For example, if one side of the outer portion 52a is 15-25 mm, for example 20 mm, then the diameter of the central portion 50a (viewed from surfaces 40b and 42b) can be 5%-20%, 20%-40%, 40%-60%, 60%-80%, and / or 80%-100% of that side, for example 1-19 mm, for example 10 mm. As mentioned above, the size and shape of the aperture 56 can form an opening that is substantially the same as or smaller than that of the central portion 50, viewed from surfaces 40b and 42b.

[0041] Figure 4 shows an example of how the beam splitter in Figure 1 is used to direct light from the sample and overlay projector toward the camera and / or eyepiece, according to a particular embodiment.

[0042] Step 110 begins the explanation of how the beam splitter directs the light from the sample. In step 110, the sample incident surface of the beam splitter receives the light from the sample. In step 112, the outer portion of the inner plane of the beam splitter transmits the sample light toward the eyepiece. In step 114, the eyepiece exit surface of the beam splitter transmits the light toward the eyepiece. In step 116, the central portion of the inner plane transmits a portion of the sample light toward the eyepiece, and in step 114, the eyepiece exit surface transmits the light toward the eyepiece. In step 118, the central portion reflects the remaining sample light toward the camera, and in step 120, the camera exit surface of the beam splitter transmits the light toward the camera.

[0043] Step 130 begins the explanation of how the beam splitter directs the light from the overlay projector. In step 130, the projector incident surface of the beam splitter receives light from the overlay projector. In step 132, the outer portion transmits the overlay projector light, and in step 134, the aperture blocks at least some of that light from reaching the camera. In step 136, the central portion reflects the overlay projector light towards the eyepiece. In step 114, the eyepiece exit surface transmits that light towards the eyepiece.

[0044] While this disclosure describes certain embodiments, modifications to these embodiments (e.g., changes, substitutions, additions, omissions, and / or other modifications) will be obvious to those skilled in the art. Therefore, modifications to these embodiments can be made without departing from the scope of the invention. For example, modifications can be made to the systems and apparatus disclosed herein. As will be obvious to those skilled in the art, the components of the systems and apparatus may be integrated or separate, or the operation of the systems and apparatus may be performed by more components, fewer components, or other components. Another example is the modification of the methods disclosed herein. As will be obvious to those skilled in the art, the methods may include more steps, fewer steps, or other steps, and the steps may be performed in any suitable order.

[0045] To assist the interpretation of the patent claims by the Patent Office and readers, the applicants note that no claim or claim element is intended to be subject to Section 112(f) of the U.S. Patent Act unless the terms “means to” or “steps to” are expressly used in a particular claim. The applicants also understand that any other terms used in the claims (e.g., “mechanism,” “module,” “device,” “unit,” “component,” “element,” “member,” “apparatus,” “machine,” “system,” “processor,” or “controller”) refer to structures known to those skilled in the art, and therefore are not intended to be subject to Section 112(f) of the U.S. Patent Act.

Claims

1. It is a beam splitter, A substrate containing a transparent material, comprising an axis, The first surface is configured to receive light from the sample, A second surface configured to transmit light toward the eyepiece, A third surface configured to receive light from an overlay projector, and A fourth surface configured to transmit light towards the camera. A substrate having multiple surfaces including, The internal plane within the substrate, The central reflective portion, By transmitting a portion of the light from the first surface to the second surface, the light from the sample is directed toward the eyepiece. By reflecting the remaining portion of the light from the first surface to the fourth surface, the light from the sample is directed toward the camera. By reflecting light from the third surface to the first surface, the light from the overlay projector is directed toward the eyepiece. A central reflective section configured as follows, The outer permeable portion, By transmitting light from the first surface to the second surface, the light from the sample is directed toward the eyepiece. By transmitting light from the third surface to the fourth surface, the light from the overlay projector is directed toward an aperture configured to block the light. The outer transparent section is configured as follows, An internal plane including, A beam splitter that includes [a specific component].

2. The beam splitter according to claim 1, wherein the internal plane is positioned at an angle of 40 to 50 degrees with respect to the axis of the substrate.

3. The beam splitter according to claim 1, wherein the central reflective portion has its center substantially at the center of the outer transmissive portion.

4. The beam splitter according to claim 1, wherein the central reflective portion is offset from the center of the outer transmissive portion.

5. The beam splitter according to claim 1, wherein the central reflective portion has a substantially square shape when viewed from the third surface.

6. The beam splitter according to claim 1, wherein the central reflective portion has a substantially circular shape when viewed from the third surface.

7. The beam splitter according to claim 1, wherein the central partial reflecting portion has a polarizing filter configured to transmit light having a first polarization and reflect light having a second polarization.

8. The beam splitter according to claim 7, wherein the light from the sample has the first polarization and the second polarization.

9. The beam splitter according to claim 7, wherein the light from the overlay projector has the second polarization.

10. The beam splitter according to claim 1, wherein the aperture forms an opening having substantially the same shape as the central partial reflector.

11. The beam splitter according to claim 1, wherein the aperture forms an opening that is up to 20% smaller than the central reflective portion.

12. A method for directing light, The beam splitter receives light from a sample and an overlay projector, wherein the beam splitter has a substrate containing a transparent material, the substrate has an axis and an internal plane having a central partial reflector and an outer transmissive portion, and the substrate includes a first surface configured to receive light from the sample, a second surface configured to transmit light toward the eyepiece, a third surface configured to receive light from the overlay projector, and a fourth surface configured to transmit light toward the camera. The outer transmissive portion transmits light from the first surface to the second surface, thereby directing the light from the sample toward the eyepiece. The aforementioned central reflective portion transmits a portion of the light from the first surface to the second surface, thereby directing the light from the sample toward the eyepiece. The central reflective portion directs the light from the sample toward the camera by reflecting the remaining portion of the light from the first surface to the fourth surface. The outer transparent portion transmits light from the third surface to the fourth surface, thereby directing the light from the overlay projector toward the aperture. The aperture blocks the light received from the fourth surface, The aforementioned central reflective portion directs the light from the overlay projector toward the eyepiece by reflecting light from the third surface to the first surface. A method that includes this.

13. The method according to claim 12, wherein the internal plane is positioned at an angle of 40 to 50 degrees with respect to the axis of the substrate.

14. The method according to claim 12, wherein the central reflective portion substantially has its center at the center of the outer transmissive portion.

15. The method according to claim 12, wherein the central reflective portion is offset from the center of the outer transmissive portion.

16. The polarizing filter in the central reflective portion transmits light having the first polarization. The method according to claim 12, further comprising reflecting light having a second polarization with the polarizing filter, wherein the light from the sample has the first polarization and the second polarization, and the light from the overlay projector has the second polarization.

17. The method according to claim 12, wherein the aperture forms an opening having substantially the same shape as the central partial reflecting portion.

18. The method according to claim 12, wherein the aperture forms an opening that is up to 20 percent smaller than the central partial reflector.

19. It is a beam splitter, A substrate containing a transparent material, comprising an axis, The first surface is configured to receive light from the sample, A second surface configured to transmit light toward the eyepiece, A third surface configured to receive light from an overlay projector, and A fourth surface configured to transmit light towards the camera. A substrate having multiple surfaces including, An internal plane within the substrate, positioned at an angle of 40 to 50 degrees with respect to the axis of the substrate, The central reflective portion, By transmitting a portion of the light from the first surface to the second surface, the light from the sample is directed toward the eyepiece. By reflecting the remaining portion of the light from the first surface to the fourth surface, the light from the sample is directed toward the camera. By reflecting light from the third surface to the first surface, the light from the overlay projector is directed toward the eyepiece. A central reflective section configured as follows, The outer permeable portion, By transmitting light from the first surface to the second surface, the light from the sample is directed toward the eyepiece. By transmitting light from the third surface to the fourth surface, the light from the overlay projector is directed toward an aperture configured to block the light. The outer transparent section is configured as follows, An internal plane including, Includes, A beam splitter wherein the aperture forms an opening having substantially the same shape as the central partial reflector, and the opening is up to 20 percent smaller than the central partial reflector.

20. The beam splitter according to claim 19, wherein the central partial reflecting portion has a polarizing filter configured to transmit light having a first polarization and reflect light having a second polarization, the light from the sample has the first polarization and the second polarization, and the light from the overlay projector has the second polarization.

Images