Abstract:
An optometer for subjectively examining refractive power of an examinee&#39;s eye, comprises: a phoropter which selectively disposes an optical element in front of the examinee&#39;s eye; a controller having a switch panel for transmitting a signal to the phoropter and a horizontally extending rotation axis; a display rotatable about the rotation axis of the controller, orientation of the display being changeable by its rotation between a side with the switch panel and a side without the switch panel; and a control part which controls a display screen of the display to appear in a constant orientation irrespective of whether the display is reversed upside down by its rotation.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an optometer (a vision tester) for subjective examination (measurement) of refractive power and others of an examinee&#39;s eye.  
         [0003]     2. Description of Related Art  
         [0004]     There is an optometer (a vision tester) having a main unit (a phoropter) arranged to dispose optical elements such as a sphere lens and a cylinder lens in front of an examinee&#39;s eye and a controller, and the optometer being structured to perform subjective examination (far vision test) on refractive power and others of the examinee&#39;s eye by allowing an examinee to view an optotype presented at a predetermined distance for far vision test apart from the examinee&#39;s eye. This optometer is adapted to change the optical elements to be disposed in front of the examinee&#39;s eye by operation of the controller by an examiner. The controller is provided with a display which displays various kinds of optometry information such as information on the optical element disposed in front of the examinee&#39;s eye.  
         [0005]     Recently, an optometer capable of performing near vision test using this type of controller (an optometer in which the display of the controller is also used as an optotype presenting unit for near vision test) has been proposed (see Japanese unexamined patent publication No. 9(1997)-299332). However, this apparatus is structured so that the entire controller or the display separately located from a switch panel (an operating part) of the controller is turned to the examinee. It is therefore poor in usability.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     The present invention has been made in view of the above circumstances and has an object to provide an optometer with an easy-to-use controller.  
         [0007]     Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.  
         [0008]     To achieve the above purpose, the invention provides an optometer for subjectively examining refractive power of an examinee&#39;s eye, comprising: a phoropter which selectively disposes an optical element in front of the examinee&#39;s eye; a controller having a switch panel for transmitting a signal to the phoropter and a horizontally extending rotation axis; a display rotatable about the rotation axis of the controller, orientation of the display being changeable by its rotation between a side with the switch panel and a side without the switch panel; and a control part which controls a display screen of the display to appear in a constant orientation irrespective of whether the display is reversed upside down by its rotation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate an embodiment of the invention and, together with the description, serve to explain the objects, advantages and principles of the invention.  
         [0010]     In the drawings,  
         [0011]      FIG. 1  is a schematic structural view of an optometry system including an optometer in a preferred embodiment of the present invention;  
         [0012]      FIG. 2  is a schematic external view of a main unit (a phoropter) of the optometer, viewed from an examinee side;  
         [0013]      FIGS. 3A and 3B  are schematic external views of a controller of the optometer;  
         [0014]      FIG. 4  is a schematic structural view of a rotation mechanism of a display unit;  
         [0015]      FIGS. 5A and 5B  are schematic structural views of the rotation mechanism of the display unit;  
         [0016]      FIG. 6  is a schematic external view of the controller viewed from above;  
         [0017]      FIG. 7  is a view showing an example of a screen for examiner, displayed on the display;  
         [0018]      FIG. 8  is a view showing an example of a screen for examinee, displayed on the display;  
         [0019]      FIG. 9  is a view showing an example of a screen presenting a price list of spectacle lenses; and  
         [0020]      FIG. 10  is a schematic block diagram of a control system of the optometry system. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     A detailed description of a preferred embodiment of the present invention will now be given referring to the accompanying drawings.  
         [0022]      FIG. 1  is a schematic structural view of an optometry system including an optometer (a vision tester) in the preferred embodiment of the present invention.  FIG. 2  is a schematic external view of a main unit (a phoropter)  1  of the optometer, viewed from an examinee side.  FIGS. 3A and 3B  are schematic external views of a controller  9  of the optometer.  
         [0023]     The phoropter  1  of the optometer includes a pair of lens chamber units (optometric units)  60  symmetrical in right and left configuration each having a test window  61 , and a supporting part  6  which supports the lens chamber units  60  in a hanging state. The supporting part  6  is internally provided with a movement mechanism  50  (see  FIG. 10 ) including a sliding mechanism for adjusting a distance between the lens chamber units  60  and a convergence mechanism for adjusting a convergence angle of the lens chamber units  60 . A forehead rest  70  attached to the supporting part  6  is used for supporting the head of an examinee to fix the examinee&#39;s eye(s) in a predetermined test position.  
         [0024]     Each of the lens chamber units  60  holds, in its casing, a plurality of rotatable lens disks  64  in each of which a plurality of various optical elements  65  (including an opening) such as a sphere lens, a cylinder lens, a cross-cylinder lens, a red filter, a green filter, a polarizing filter, and a shielding plate are circumferentially arranged (held) on the same circle. These disks  64  are rotated individually by a rotation mechanism  63  (see  FIG. 10 ) to dispose one of the optical elements  65  of each disk  64  in the test window  61 .  
         [0025]     The phoropter  1  is supported above a table  10  by a support arm  4  attached to the table  10 . By operation of an up-down switch  11 , the height of a top plate of the table  10 , that is, the height of the phoropter  1  is adjusted by a movement mechanism not shown.  
         [0026]     An optotype presenting device  20  for far vision test ( FIG. 1  shows a schematic internal structure thereof) is placed forward at a predetermined far-vision-test distance apart from the phoropter  1 . This optotype presenting device  20  is internally provided with an optotype presenting part  21  which presents various optotypes, a half mirror  22 , a concave mirror  23 , a window  24 , and others. Optotype light from the optotype presenting part  21  partly passes through the half mirror  22  and is reflected by the concave mirror  23 , and further partly reflected by the half mirror  22  toward the examinee&#39;s eye through the window  24 .  
         [0027]     A rod  2  on which an optotype presenting unit  3  for near vision test is mounted is attached to the supporting part  6 . The optotype presenting unit  3  has a chart on which a plurality of optotypes is drawn. This unit  3  is movable on the rod  2  along its length direction. The rod  2  is held in an up position (shown in  FIG. 1 ) except during the near vision test. During the near vision test, the rod  2  is moved down to a horizontal position and the optotype presenting unit  3  is moved to a forward position at a predetermined distance for near vision test apart from the lens chamber units  60 .  
         [0028]     A relay unit  12  is connected to the phoropter  1 , the optotype presenting device  20 , and a controller  9  which will be mentioned later. Based on signals from a control part  130  of the controller  9 , a control part  120  of the relay unit  12  transmits signals to a control part  140  of the phoropter  1  and a control part  150  of the optotype presenting device  20 .  
         [0029]     In the present embodiment, the controller  9  serving as an operating unit for the phoropter  1  is also used as an operating unit for the optotype presenting device  20 . A supporting part  32  extending upward from a base unit  31  of the controller  9  rotatably supports a display unit  30  provided with a color liquid crystal display (monitor)  300 . The display  300  is of a touch panel function enabling switch operations even on a display screen (which will be mentioned later in more detail). A switch panel (operating part)  35  provided on the base unit  31  includes various kinds of switches (which will be mentioned later in more detail).  
         [0030]     A rotation mechanism of the display unit  30  will be explained.  FIG. 4  and  FIGS. 5A and 6B  are schematic structural views of the rotation mechanism of the display unit  30 . A cylindrical engagement portion  33  formed in the rear of the display unit  30  is engaged between two cylindrical engagement portions  34  provided at upper right and left ends of the supporting part  32 . Inside these engagement portions  33  and  34 , a rotary hinge  42  is arranged  80  that one hinge plate  44   a  rotatable with respect to a joint  43  of the hinge  42  is secured by a screw  45   a  to a plate  30   a  fixed to a base plate  300   a  of the display  300  and the other hinge plate  44   b  rotatable with respect to the joint  43  is secured by a screw  45   b  to a base plate  32   a  inside the supporting part  32 . With this configuration, the display unit  30  can be rotated about a horizontally extending axis A which is a rotational central axis of the hinge  42 . This structure makes it possible to change the orientation of the display unit  30  between a position where the display  300  faces to the side with the switch panel  35  (an examiner side) (i.e. the position in  FIGS. 3A, 4 , and  5 A) and a position where the display  300  faces to the side without the switch panel  35  (an examinee side) (i.e. the position in  FIGS. 3B and 5B ).  
         [0031]     A mechanism for detecting the orientation of the display unit  30  (the display  300 ) will be explained. A U-shaped photosensor (photointerrupter)  40  is attached to a plate  46  secured to the base plate  32   a  by a screw  47  and a shielding plate  41  is attached to a plate  48  secured to the plate  30   a  by a screw  49 . While the display  300  is oriented to face to the examiner side ( FIG. 5A ), the shielding plate  41  is inserted in the photosensor  40 . While the display  300  is oriented to face to the examinee side ( FIG. 5B ), the shielding plate  41  is moved out of the photosensor  40 . Accordingly, the orientation of the display unit  30  (the display  300 ) is detected based on a detection signal of the photosensor  40 .  
         [0032]     The switch panel  35  will be explained.  FIG. 6  is a schematic external view of the controller  9 , viewed from above. The switch panol  35  is provided with a dial switch  36  for increasing/decreasing numeric values, a [Menu] switch  37  for setting and changing a display mode, a [Mode] switch  38  for switching to a mode of changing data on for example sphere power [S], cylinder power [C], and a cylinder axis angle [A], a [Program] switch  39  including a [Start] switch for an optometry program, and other switches. A [PD] switch of the [Mode] switch  38  is used to adjust the positions of the right and left test windows  61  to an interpupillary distance of the examinee. When the [PD] switch is operated (pressed) and successively the dial switch  36  is operated (turned), the distance between the lens chamber units  60  is adjusted by the movement mechanism  50 . An [ADD] switch of the [Mode] switch  38  is used to adjust the positions of the right and left test windows  61  to the convergence angle of the examinee. When the [ADD] switch is operated (pressed), the convergence angle between the lens chamber units  60  is adjusted by the movement mechanism  50 .  
         [0033]     A display screen on the display  300  will be explained.  FIG. 7  is a view showing an example of a screen for examiner, displayed on the display  300 . A screen  80  for examiner displayed on the display  300  includes information on the optical elements  65  disposed in the right and left test windows  61 , information on refractive power measured by an external device and input to the present device (an [LM] frame indicates information on refractive power of examinee&#39;s own spectacles or contact lenses measured by a lensmeter, and an [AR] frame indicates information on refractive power of the examinee&#39;s eye measured by an objective refractive power measurement device called auto-refractometer), and other information. Icons (touch-panel switches)  81  are operated (touched) to select (switch) optotypes to be presented by the optotype presenting device  20 . Information on the currently presented (selected) optotypes is displayed on a frame  81   a.  The touch panel function of the display  300  is used for operation of the optotype presenting device  20 . Accordingly, even when the optotype presenting device  20  is replaced with a device of a different type, this device can easily be operated if only displaying software for the display  300  is changed to a corresponding one. Displayed in a frame  84  is information on the optical elements  65  disposed in the right and left test windows  61 .  
         [0034]      FIG. 8  is a view showing an example of a screen for examinee, displayed on the display  300 . Icons  101  are operated (touched) to select (switch) a screen  100  for examinee to be displayed on the display  300 . The screen  100  in  FIG. 8  is an optotype presenting screen (selected by a [Near VA] icon) for near vision test. Other screens  100  may include a screen (selected by a [Vision] icon) showing an examinee as to differences in vision between myopia, hyperopia, astigma, and others, a screen (selected by an [Eyeball] icon) showing a structural drawing of an eye, a screen (selected by an [Ametro.] icon) showing a drawing of refractive power of an eye with myopia, hyperopia, astigma, and others, a newspaper screen (selected by a [News P.] icon) and a musical score screen (selected by an [M. Score] icon) which are used for documents to be viewed by an examinee at a near vision distance (a short distance), and other screens. Using these screens  100 , the examiner can explain about refractive errors and perform simple checks as to differences in vision, etc. With the touch of an [Other] icon, further, a screen showing sales promotional materials such as a price list of spectacle lenses (see  FIG. 9 ). The screen  100  may be arbitrarily configured.  
         [0035]     The operation of the optometry system having the above structure will be explained below.  FIG. 10  is a schematic block diagram of a control system of the optometry system. Preferably, prior to the test, refractive power (sphere power, cylinder power, and a cylinder axis angle) and an interpupillary distance of the examinee&#39;s eyes are measured by an objective refractive power measurement device not shown. By operation of an [AR] switch on the controller  9 , those measured values are input into the control part  130  of the controller  9 , the control part  140  of the phoropter  1  and the control part  150  of the optotype presenting device  20  via the control part  120  of the relay unit  12 , respectively. In the case where the examinee wears spectacles or contact lenses, its refractive power (sphere power, cylinder power, and a cylinder axis angle) is measured by a lensmeter not shown. By operation of an [LM] switch on the controller  9 , those measured values are input into the control part  130  and the control parts  140  and  150  via the control part  120 . The control part  140  controls the movement mechanism  50  based on the input interpupillary distance to adjust the distance between the lens chamber units  60 . To additionally adjust the lens chamber units  60 , the [PD] switch on the controller  9  and the dial switch  36  have to be operated, so that the control part  140  further controls the movement mechanism  50  to adjust the distance between the lens chamber units  60 .  
         [0036]     In the test, the control part  140  controls the rotation mechanism  64  based on the input refractive power to dispose one of the plurality of optical elements  65  arranged in each disk  64 , into each test window  61 . The control part  150  controls the optotype presenting unit  21  based on the input refractive power to present an appropriate optotype.  
         [0037]     When the optotype presented by the optotype presenting device  2  is to be changed, the icons  81  on the screen  80  for examiner are operated and thus the control part  130  transmits a command signal to the control part  150  via the control part  120 . The control part  150  controls the optotype presenting unit  21  based on the command signal to present a selected optotype. At this time, the control part  130  displays the information on the selected optotype in the frame  81   a.    
         [0038]     When the optical element  65  disposed in each test window  61  is to be changed, an [S] switch, a [C] switch, an [A] switch, and others of the [Mode] switch  38  on the controller  9  and the dial switch  36  are operated. Thus, the control part  130  transmits a command signal to the control part  140  via the control part  120 . The control part  140  controls the rotation mechanism  63  based on the command signal to dispose a selected one of the optical elements  65  in the test window  61 . At this time, the control part  130  displays the information on the selected optical element  65  in the frame  84 .  
         [0039]     When the refractive power of the examinee&#39;s eye are obtained by presenting optotypes, disposing the optical elements  65 , and so on, the [Menu] switch  37  is operated to display a menu screen not shown on the display  300 . By operation of the icon appearing on this menu screen, the screen  100  for examinee is called up. When the screen  100  is displayed, the display unit  30  is rotated to turn the display  300  from a position facing to the switch panel  35  side (the examiner side) to a position facing to the opposite side (the examinee side). When the display unit  30  is rotated, the display screen of the display  300  is displayed in a vertically and horizontally inverted state, or turned 180°, from the display screen at the position facing to the examiner side. This inversion is performed by the control part  130  which detects the orientation of the display  300  based on a detection signal of the photosensor  40  and controls the display screen of the display  300 . Accordingly, even when the display  300  is turned upside down by rotation of the display unit  30 , the orientation of the display screen of the display  300  can be constant.  
         [0040]     When the display  300  is turned toward the examinee, the examiner moves to the examinee side and operates the icons  101  to display various screens  100 . To return the screen  100  for examinee to the screen  80  for examiner, the [Menu] switch  37  and others are operated again.  
         [0041]     While the screen  100  is displayed on the display  300 , the control part  130  does not accept signals from the [Mode] switch  38 , [Program] switch  39 , and others. This makes it possible to prevent improper operations of the system (device).  
         [0042]     In the present embodiment, the display screen on the display  300  is changed from the screen for examiner to the screen for examinee when the [Menu] switch  37  and others are operated. Alternatively, the display screen may be changed from the screen for examiner to the screen for examinee by rotation of the display unit  30  to turn the display  300  from the position facing to the examiner side to the position facing to the examinee side. In this case, the display screen is changed from the screen for examinee to the screen for examiner when the display  300  is returned to an original position (orientation).  
         [0043]     In the present embodiment, further, acceptance of signals from the switch panel  35  is restricted as soon as the display screen on the display  300  is changed from the screen for examiner to the screen for examinee. Alternatively, the switch operation may be restricted when the display  300  is turned to the position facing to the examinee side.  
         [0044]     The display unit  30  of the controller  9  may be provided with a small display in the rear of the display  300 . On this small display, as with the display  300 , the screen for examines is displayed when the display screen on the display  300  is changed from the screen for examiner to the screen for examinee. Accordingly, the examiner is not required to move to the examinee side even while the display  300  faces to the examinee side.  
         [0045]     While the presently preferred embodiment of the present invention has been shown and described, it is to be understood that this disclosure is for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims.