Background of the Invention
1. Field of the Invention
This invention relates to an integrated beam splitter and adjustable light intensity control adapter and more particularly to an adapter including an attachment means for having an optical device which produces an optical image connected to one opening and a viewing means to enable a user to observe the image and a separate attachment for a video camera recording means to record the optical image from the optical device. An adjustable iris controls the intensity of the optical image received by the video recording means.
2. Disclosure of the Prior Art
It is known in the prior art to utilize a beam splitter in combination with a viewing means and a video camera recording means. Also, use of an iris or other light intensity controlling means are known in the prior art. One such system is sold by the assignee of the present invention which is known as an "Endo Video Beam Splitter". This present device is useful but has relatively long optical paths and is used primarily in medical and surgical applications.
Beam splitters are used in the medical industry in cooperation with optical devices used primarily in surgical applications wherein a second observer or a recording device can view the same optical image as the user or surgeon, such as for example, an optical image from an endoscope.
Summary of the Invention
This invention relates to a new and novel integrated beam splitter and adjustable light intensity control adapter for use primarily in the medical and surgical field. The adapter includes a housing having at least a first and second hollowed-out area, openings to receive an optical image from an optical device attached to the housing, an opening for an eyepiece and optics in the form of a beam splitter and a prism for producing two optical images of different intensities, one of which is directed through an eyepiece for a viewer to observe the optical image and a second through the optics to a recording means, such as a video camera. An adjustable light intensity means is provided, which may be manual or automatic, for controlling the intensity of the optical image received by the camera.
The adapter of the present invention overcomes several problems associated with the prior art devices. One advantage is that a single, compact, small, light weight housing includes all of the elements in an integrated assembly while providing relatively short focal length compared to the prior art devices with large diameter lens, which reduces light losses of optical images from optical devices used in medical and surgical applications while resulting in improved "F-Stop" based upon the ratio of the focal length of the lens to the lens diameter.
For example, an endoscope used in the medical profession produces a small optical image having relatively low level light intensity. Thus, any reduction in loss of light intensity becomes significant in that a minimum amount of light intensity is required to record an acceptable image by the video camera.
Another advantage of the present invention is that the video camera is mounted on and located on a planar surface of the housing in a position so as not to interfere with the viewer using the adapter.
Yet another advantage of the present invention is that an adjustable light intensity control means, such as an adjustable iris, can be used to select the required light intensity presented to the surface of the video camera.
Brief Description of the Drawing
The foregoing and other advantages and features of the invention will be apparent from the following description of the preferred embodiment of the invention when considered together with the illustrations in the accompanying drawings and includes the following figures:
FIG. 1 is a perspective view of an adapter of the present invention having an optical device, eyepiece, and video camera attached thereto;
FIG. 2 is a pictorial representation of the optics of the adapter;
FIG. 3 is a top pictorial representation of an automatic iris adjusting system, including an iris drive motor and gear mechanism;
FIG. 4 is a front plan pictorial view of the relationship of a beam splitter relative to the iris drive motor;
FIG. 5 is a pictorial representation of the elements forming the adapter and the relative position of the elements relative to each other in the housing; and
FIG. 6 is an isometric view of the adapter housing with the top cover removed and with a manually adjustable iris.
Description of the Preferred Embodiment
An integrated beam splitter and adjustable iris adapter is shown generally as 12 in FIG. 1. The adapter includes a housing 14 which includes, in the interior thereof, a first hollowed-out area and a second hollowed-out area. The housing 14 includes means for defining a pair of axially aligned openings 16 and 18 which extend from the exterior of a surface of the housing 14 into the interior of the first hollowed-out area enclosed therein. The second hollowed-out area includes means for defining an aperture 120, shown in FIG. 6, which is adapted to receive a recording device, such as for example, a video camera 24.
A means, such as an adapter 26, is adapted to connect an optical device, such as for example, an endoscope 20 to the housing 14. The optical device, such as the endoscope 20, produces an optical image which is directed through opening 16, which is one of the pair of openings, and into the first hollowed-out area of the housing 14. The optical image is directed through and out the other opening 18 which is the other of the pair of openings. An eyepiece 28, is operatively coupled to the housing and positioned in an axial alignment with the pair of openings 16 and 18 to enable a viewer to observe the optical image from the optical device, such as for example, the endoscope 20.
In use, an optical image is generated by the optical device, such as the endoscope 20, is passed into the adapter 14 where the optical image is divided into two parts and an optical image having a light intensity which is less than half of the light intensity optical image, is passed directly through to the eye piece 28 over a first optical path and the remainder of the optical image is deflected along a path substantially perpendicular to the axis of the axially aligned pair of openings 16 and 18 along a second optical path to the recording device which, in the preferred embodiment, is a video camera 24.
FIG. 2 illustrates the optics of the adapter in greater detail. The optical image received from the optical device, such as the endoscope 20, traverses along a first optical path designated by arrow 40. A beam splitter 42 is adapted to intercept the optical image traversing the first optical path shown by arrow 40. The beam splitter is a typical beam splitter having a partially silvered front surface 44 which has silvered surface intensity such that less than half of the intensity of the optical image is passed by the beam splitter along the first optical path designated by line segment 46.
The remainder of the optical image is deflected by the silvered surface 44 along a second optical path shown generally as 50 having path segments 52, 54, 56 and 58. The portion of the optical image deflected by the silvered surface 44 of the beam splitter 42 is deflected substantially perpendicular to the first optical path 40, which optical path is in substantial axial alignment with the pair of openings 16 and 18, as illustrated in FIG. 1.
A prism 60 is positioned continuous to a beam splitter 42 and receives and deflects the remainder of the optical image from the beam splitter along the second optical path 50, as illustrated by light path segment 54.
In the preferred embodiment, a light intensity adjusting means, such as for example, adjustable iris 70, is positioned between the prism 60 and the end of the second optical path illustrated by line segment 58 for controlling the intensity of the optical image passing through the iris 70.
In the preferred embodiment, the recording device is a video camera 24. In FIG. 2, a lens 80 is illustrated to depict the lens into the recording device, such as for example, video camera 24. In use, a light intensity adjusting means is adapted to control the intensity of the optical image at the surface of the housing 14 which is the input to the recording device, such as for example, video camera 24.
FIG. 3 illustrates the construction of an automatically adjustable iris 70, which can be driven by a motor 82 through a gear train shown generally as 84. In use, the iris, or other light intensity adjusting means, can be manually adjusted or automatically adjusted by use of a servo loop to control the intensity of the optical image incident upon the input or imaging surface of the recording device through lens 80 in FIG. 2.
In the preferred embodiment of the present invention, the iris is controlled by a motor 82 through a gear train 84. In order to maintain the compactness of the device, the beam splitter/prism combination, illustrated as beam splitter 42 in FIG. 4, is positioned above the motor 82 and drive gear 84 which controls the setting of the iris 70.
FIG. 5 illustrates diagrammatically the relative location of the various elements to produce a small, integrated, compact integrated beam splitter and adjustable iris adapter. In the embodiment illustrated in FIG. 5, the beam splitter 42 and the prism 60 are positioned adjacent to each other to keep the length of the second optical path at the shortest possible distance. Thus, by positioning the beam splitter 42 and first prism 60 continuous to each other, the path traversed by the second optical path is maintained at the shortest possible distance for concurrently being deflected through an automatically adjustable iris 70 on to the surface of a lens 80. An iris drive motor 82 is adapted to be positioned substantially parallel to the second light path passing through the iris 70 such that the iris 70 can be automatically adjusted by the motor through a gear drive 84.
FIG. 6 illustrates in greater detail the mechanical structure and details of the housing and its associated members. The housing 14 includes a first hollowed-out area 100 which is located at one end of the housing 14. A top plate of the housing has been removed to show the interior construction of the housing 14. In construction, the first opening 18 for the eyepiece would be located in the cover and is not shown in FIG. 6, but is of the type of construction illustrated in FIG. 1. The opening 18 of the pair openings 16 and 18, illustrated in FIG. 1, is located on and extends from the exterior of the surface of a housing into the interior of the first hollowed-out area 100.
A second hollowed-out area 102 is located substantially perpendicular to and communicates with the first hollowed-out area 100. The second hollowed-out area has an aperture 120 which extends from the exterior of the second hollowed-out area 102 to the exterior of the housing 14. The aperture 120 is located on a surface which is substantially perpendicular to a surface having one of the two openings 16 or 18 therein.
In the preferred embodiment illustrated in FIG. 6, the iris 70 is adapted to be either adjusted manually or through an iris motor and gear assembly 84, as illustrated in FIG. 4. In such an embodiment, the housing 14 includes a third hollowed-out area 110 which is adapted to receive a motor and a fourth hollowed-out area 112 which is adapted to receive the iris drive mechanism 84 which may be any known drive mechanism, such as for example, a gear drive, pulley drive, friction drive, or the like. The lens 80, in lens holder 114, can be adjusted through opening 116.
The primary utility of the present invention is in the medical field where a surgeon can concurrently view a patient's body segment, subject of the operation, through known medical devices such as an endoscope, microscope, or other optical device which produces an optical image. Typically, the optical device is small and circular in shape.
When the image is recorded on a video camera, only a small portion of the video frame is filled with the image. Thus, the intensity of the optical image presented to a video camera recording means can be controlled to compensate for different images of different optical intensities from different optical devices. Thus, the adapter of the present invention has utility in any application where an optical image is to be received and viewed by two users or one user and a recording means. In the broadest aspect the recording means could be a second viewer.