Abstract:
An ophthalmic examination apparatus comprises a plurality of portable ophthalmic diagnostic equipment devices having different ophthalmic diagnostic functions, such as a slit lamp and a fundus camera, a support base that supports each ophthalmic diagnostic equipment device in a way that allows the devices to be freely exchanged, and means for moving the support base horizontally and vertically. Such an arrangement needs only a mechanical connection between the devices and the support base and simplifies the ophthalmic examination system.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an ophthalmic examination apparatus, and more particularly to an ophthalmic examination apparatus having ophthalmic diagnostic equipment devices that can be used as a portable or fixed system.  
           [0003]    2. Description of the Prior Art  
           [0004]    Ophthalmic diagnostic equipment devices known in the prior art include the fundus camera, used for diagnostic examination of the eye fundus; the slit lamp, used for diagnostic examination of the anterior portion of the eye; and the tonometer, used for measuring ocular pressure. These apparatuses are divided into fixed types used in a set location, and portable types in which part of the fixed type are omitted to enable the apparatus to be carried by hand.  
           [0005]    There are also ophthalmic apparatuses that can be used as both fixed types and as portable types. Such types, as disclosed by Japanese Patent Laid-open Gazette Nos. 131317/97 and 234184/97, are configured as a portable type ophthalmic diagnostic system that can be detachably fitted to a fixed type system.  
           [0006]    However, while the portable part of the system functions as a portable diagnostic system, some of the functions remain in the main fixed part of the system, so there is a high degree of linkability between the portable and fixed portions. This means that portable type ophthalmic diagnostic equipment devices having another function cannot be fitted to the fixed type. Moreover, functionally connecting the portable and fixed types requires an electrical as well as a mechanical coupling, increasing the complexity of the connection configuration.  
           [0007]    An object of the invention is, therefore, to provide an ophthalmic examination apparatus that is structurally simple and can be readily used as a portable type or as a fixed type system.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention provides an ophthalmic examination apparatus comprising, a plurality of portable ophthalmic diagnostic equipment devices having different ophthalmic diagnostic functions, means for supporting each ophthalmic diagnostic equipment device in a way that allows each device to be freely exchanged, and means for spatially moving the supporting means.  
           [0009]    The present invention also provides an ophthalmic examination apparatus comprising, portable ophthalmic diagnostic equipment devices, means for supporting each ophthalmic diagnostic equipment device in a way that allows each device to be detachably mounted and, when a device is thus supported, effects only a mechanical coupling with the device, and means for spatially moving the supporting means.  
           [0010]    The present invention also provides an ophthalmic examination apparatus comprising, a plurality of portable ophthalmic diagnostic equipment devices having different ophthalmic diagnostic functions, means for supporting each ophthalmic diagnostic equipment device in a way that allows each device to be freely exchanged and that, when a device is thus supported, effects only a mechanical coupling with the device, and means for spatially moving the supporting means. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view showing the arrangement of one embodiment of an ophthalmic examination apparatus according to the present invention;  
         [0012]    [0012]FIG. 2 is a perspective view showing the arrangement of another embodiment of an ophthalmic examination apparatus according to the present invention;  
         [0013]    [0013]FIG. 3 is an illustrative view showing the optical system of a slit lamp; and  
         [0014]    [0014]FIG. 4 is an optical view showing the optical system of a fundus camera. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    The invention will now be described with reference to the drawings.  
         [0016]    [0016]FIGS. 1 and 2 show embodiments of an ophthalmic examination apparatus according to the invention. In the drawings, reference numeral  1  denotes a base of the ophthalmic examination apparatus, on which are fixed support uprights  2  and  3 . Disposed between the uprights  2  and  3  are a chin rest  4  on which the patient being examined rests his chin, and a headrest  5  against which the patient rests his forehead. The chin rest  4  can be moved vertically to match the position of each patient&#39;s chin.  
         [0017]    A plate  6  is mounted onto the base  1 . The plate  6  is arranged so that when a lever  8  is operated, the plate  6  is moved in a horizontal plane in directions X and Y relative to the base  1 , and when a ring  9  is turned, the plate  6  is moved vertically (direction Z). A block  7  is affixed to the plate  6 . The block  7  supports a support base  10  in such a way that the latter can rotate about the perpendicular axis. The rotation of the support base  10  is limited by a stop-screw  7   a  provided on the block  7 .  
         [0018]    A U-shaped fixing channel  10   a  is formed in the support base  10 . The fixing channel  10   a  can be used to attach portable ophthalmic diagnostic equipment devices having various functions.  
         [0019]    The slit lamp  20  shown in FIG. 1 is an example of a portable ophthalmic diagnostic equipment device. The slit lamp  20  has an insertion base  21  that can be inserted into the fixing channel  10   a . The insertion base  21  has a pressure member  21   a  that is urged outwards by a spring. When the base  21  is inserted into the fixing channel  10   a , the pressure member  21   a  is pressed inwards, allowing the slit lamp  20  to be inserted into the support base  10 . When the slit lamp  20  is fully inserted, the outward spring pressure of the pressure member  21   a  keeps the slit lamp  20  securely attached to the support base  10 . The slit lamp  20  can be removed by drawing the lamp back out, which pushes the pressure member  21   a  inwards, thereby enabling the slit lamp  20  to be fully removed.  
         [0020]    A slit projection section  22  is rotatably mounted on the insertion base  21 , with axis  21   b  as the axis of rotation. The slit lamp  20  also has a grip  24 . The examiner uses the grip  24  to project the slit image onto the anterior portion of the patient&#39;s eye, via a projection window  22   a , and, via eyepiece  23 , observes the slit image coming from the eye.  
         [0021]    [0021]FIG. 3 shows the optical system of the slit lamp  20 . A beam of light from a lamp  31  is converted to a parallel beam by lens  32  and then passes via a slit  33  and a mirror  34  to be projected onto the anterior portion of the patient&#39;s eye E. The image of the anterior portion of the eye projected by the slit light passes via imaging lens  35  and eyepiece lens  36  for observation by the examiner S.  
         [0022]    The slit lamp  20  itself functions as a portable type ophthalmic diagnostic device. When used for diagnostic purposes, the examiner grasps the grip  24  and switches on lamp  31  to project the slit light onto the anterior portion of the eye. Diagnosis is performed by observing the image of the reflected light through the eyepiece  23 . The portability of the slit lamp  20  makes it suitable for diagnostic examinations of bedridden patients such as elderly persons as well as infants and the like. However, its very portability can be a drawback, in that it cannot be held completely still during examinations.  
         [0023]    Therefore, when the examiner wishes to conduct a more stable, reliable examination, he inserts the insertion base  21  of the slit lamp  20  into the fixing channel  10   a  of the support base  10  to thereby mechanically couple the slit lamp  20  to the support base  10 .  
         [0024]    The examiner can conduct an eye examination for the patient sitting with his chin against the chin rest  4  in the same way as when the slit lamp  20  is being used as a portable system. The examiner uses the lever  8  and ring  9  to move the plate  6  horizontally and vertically to adjust the position of the slit image, and rotates the slit projection section  22  or support base  10  to adjust the direction in which the slit image is projected.  
         [0025]    Thus, since the slit lamp  20  can detachably mounted on the support base  10  affixed to the plate  6 , it can be used as a portable type device and as a fixed type. Since the slit lamp is only coupled to the support base  10  mechanically when used as a fixed type, it enables the arrangement of the fixed part to be simplified.  
         [0026]    Other ophthalmic devices can also be used as fixed types simply by considering a mechanical coupling, i.e. by ensuring that the shape of the insertion base matches the fixing channel. FIG. 2 shows an example of this, in the form of a fundus camera  40 . The camera  40  illuminates the fundus of a patient&#39;s eye and captures images of the fundus. For this, the examiner holds the body  41  of the camera and uses a switch  43  to project light through a projection window  42  to illuminate the fundus. Fundus images can be observed via an eyepiece  44 , or captured using an imaging section  45  constituted by a photographic camera or CCD camera or the like.  
         [0027]    [0027]FIG. 4 shows the optical system of the fundus camera  40 . Illuminating light from an illumination light source and illumination optical system (not shown) is projected onto the fundus of the eye E via a prism  51 . Light reflected by the fundus passes through objective lenses  52  and focusing lens  53  and falls incident on a return mirror  54 . The light reflected by the return mirror  54  is then reflected by a mirror  55 , and is directed to the examiner S via a field lens  56  and an eyepiece lens  58 . With the return mirror  54  removed from the optical path, a flash lamp (not shown) positioned in the vicinity of the illumination light source is turned on to record images on film or another such recording medium  57 .  
         [0028]    Thus, the fundus camera  40  itself functions as a portable type ophthalmic diagnostic device, and can be used to examine the eyes of disabled patients and the like. When there is a risk that hand movement will make conditions too unstable for an examination, or when it is desired to use the camera as a fixed type system, the camera can be mounted on to the support base  10  of the plate  6  by using an adapter  50  equipped with an insertion base  46  for insertion into the fixing channel  10   a.    
         [0029]    The insertion base  46  also has a spring-loaded pressure member  46   a  that enables the insertion base  46  to be detachably mounted on the support base  10 . Also affixed to the insertion base  46 , via a support  47 , is a fixing frame  48 . To use, the examiner opens a cover  49 , fits the camera  40  to the fixing frame  48 , and then clamps the camera in place on the adaptor  50  by latching the cover hook  49   a  onto the lockpiece  48   a . The camera is then fitted onto the fixed part of the system by sliding the insertion base  46  into the support base  10 .  
         [0030]    In this way, the examiner can use the camera  40  to examine and/or capture images of the eye in the same way as when the camera is being used as a portable system. The examiner uses the lever  8  and ring  9  to move the plate  6  horizontally and vertically to align the camera with the eye, and rotates the support base  10  to adjust the direction in which the fundus image is viewed or captured.  
         [0031]    While this embodiment uses an adaptor  50  to fit the fundus camera  40  onto the plate  6 , the camera may instead be provided with an insertion base to enable the camera to be mounted without using an adaptor.  
         [0032]    Similarly, the electrical feed for the illumination lamp and illumination light source of the slit lamp  20  and camera  40 , and the requisite power supply, can be incorporated internally or provided externally via a power cord. Even if power is provided externally, there is no need to provide an electrical connection between a device to be mounted and the fixed part of the system for receiving the device because the power does not have to be supplied via the fixed part of the system. This simplifies the system arrangement and reduces the cost.  
         [0033]    While the aspects of the invention have been described using a slit lamp and fundus camera as examples, the invention also applies to other ophthalmic diagnostic devices, such as an ocular tonometer or other such device configured as a portable system, which can be used as a fixed system using the support base  10  on the plate  6  as shown in FIGS. 1 and 2.  
         [0034]    As described in the foregoing, the present invention provides a simplified ophthalmic examination apparatus in which various ophthalmic diagnostic devices can be used as portable and as fixed system devices. As such, the invention can be used to build ophthalmic examination systems for a wide range of ophthalmic diagnostic applications. Moreover, when a portable device is used as a fixed system, it is only mechanically linked to the fixed part. This simplifies the arrangement of the fixed portion and also allows various ophthalmic diagnostic devices to be fitted to the fixed part.