Ophthalmic Apparatus Including an Apparatus Control Mechanism Having Multiple Modes

1. Field of the Invention

The present invention relates to an ophthalmic apparatus.

2. Related Background Art

A fundus camera, an autorefractometer, a noncontact tonometer, and the like are known as ophthalmic apparatuses. Most of these apparatuses use joysticks for positioning the apparatuses relative to eyes to be examined. An independent rotary mechanism is arranged in or near the joystick and used as an input means to control vertical movement of the main body of the apparatus and the illumination light amount.

However, such a conventional rotary mechanism always has a single function as an input means. For this reason, control is often performed using a large number of switches. For example, in vertical movement control of a measuring portion using a rotary mechanism arranged in a joystick, the rotary mechanism of the joystick can control only vertical movement. For example, even if various conditions which do not require positioning of a patient are to be set in practice, independent switches are required, and the function of the rotary mechanism of the joystick is of no use during setting the above conditions. In particular, when an examiner is allowed to select a specific one of a plurality of items or an optimal one of a plurality of continuously changing states, the examiner must depress a specific switch a plurality of number of times or must keep depressing a switch for a long period of time, resulting in poor operability.

The present invention has been made in consideration of the conventional problems described above, and has as its first object to provide an ophthalmic apparatus capable of decreasing the number of switches, reducing cost, facilitating the operations, and improving operability.

Other objects, features, and advantages of the present invention will be apparent from the following detailed description in conjunction of the accompanying drawings.

FIG. 1 is a perspective view showing an autorefkeratometer according to an embodiment of the present invention;

FIG. 2 is a plan view of switches arranged on a switch panel;

FIG. 3 is a view showing a measurement screen;

FIG. 4 is a view showing a measurement screen in a mode for measuring an eye inserted with an intraocular lens;

FIG. 5 is a view showing a corneal shape measurement screen;

FIG. 6 is a view showing a corneal size measurement screen;

FIG. 7 is a view showing a diaphanoscopy observation screen;

FIG. 8 is a view showing a screen for setting various measurement conditions;

FIG. 9 is a view showing a shape measurement screen for a portion around a cornea;

FIG. 10 is a view showing a message input screen;

FIG. 11 is a view showing the structure of a joystick;

FIG. 12 is a view showing the structure of a jog dial;

FIG. 13 is a block diagram showing the overall electrical circuit;

FIG. 14 is a perspective view showing a nonscattering pupil fundus camera according to another embodiment of the present invention;

FIG. 15 is a view showing a screen in a normal fundus photographing mode; and

FIG. 16 is a view showing a date input screen.

FIG. 1 is a perspective view showing an autorefkeratometer according to an embodiment of the present invention. This apparatus comprises a movable portion 2 moved to position an eye to be examined with respect to a stationary portion 1. The movable portion 2 includes a joystick 3 used for allowing an examiner to position the eye to be examined, a jog dial 4 for setting various conditions, a CRT monitor 5 for monitoring an anterior eye portion of the eye to be examined, and a switch panel 6 having various switches thereon. A measurement value is output to a printer 7 incorporated in the main body of this apparatus. The joystick 3 is pivoted in all directions to finely position the movable portion 2 with respect to the eye to be examined. The joystick 3 is rotated to vertically move a measurement portion 8 of the movable portion 2, thereby adjusting the height. In practice, this apparatus includes an encoder for driving and controlling a motor arranged therein. Rotation of the joystick is detected by this encoder, and the motor is driven on the basis of the detected rotation information. For example, when the joystick is rotated clockwise, the measurement portion 8 is moved upward; when the joystick is rotated counterclockwise, the measurement portion 8 is moved downward.

FIG. 2 shows the layout of switches on the switch panel 6. A print switch 61, a set switch 62 for storing various settings, an IOL switch 63 for measuring an eye inserted with an intraocular lens, a mode switch 64 for switching between an autorefractometer function and an autokeratometer function, an observation switch 65 for performing diaphanoscopy observation, and a corneal size measurement mode switch 66 for switching to a mode for measuring the diameter of a cornea are arranged on the switch panel 6.

FIG. 3 is a view showing the screen on the CRT monitor 5 in the refractive index measurement of the autorefkeratometer. In this state, the jog dial 4 functions as an input means for changing the distance between vertices. "JOG VD:12.0" indicates to the examiner that the distance between the vertices can be changed by rotation of the jog dial 4, and also indicates that the current distance between the vertices is 12.0. In practice, when the jog dial 4 is rotated clockwise, the distance between the vertices is toggled in an order of 0.0, 12.0, 13.5, and 15.0. When the jog dial 4 is rotated counterclockwise, the toggling order is reversed.

FIG. 4 shows the screen on the CRT monitor 5 when the IOL switch 63 is depressed from the state in FIG. 3 to change the screen to the mode for measuring an eye inserted with an intraocular lens. In this case, the jog dial 4 serves as an input means for changing the brightness of a target gazed with an eye to be examined. On the screen, "JOG FIX=50" is displayed. With this display, the examiner can see that the brightness of the target gazed with the eye to be examined can be changed by rotation of the jog dial 4. The display also indicates that the current brightness of the target is 50. In this case, when the jog dial 4 is rotated clockwise, the brightness of the target increases; when the jog dial 4 is rotated counterclockwise, the brightness of the target decreases. In this case, the setting of the brightness of the target which is required for each examiner is assumed to depend on personal differences of examiners. For this reason, after a measurement value is printed out upon depressing a print switch, the set value is restored to the initial set value prestored in the apparatus.

FIG. 5 shows the screen in a mode in which the refracting power and the corneal radius of curvature are simultaneously measured. This mode can be selected by the mode switch 64. In this case, "JOG:mm/D" is displayed. This indicates that the display unit of the corneal radius of curvature can be changed from mm to Diopter during rotation of the jog dial 4, and vice versa. The examiner observes this display and recognizes that the current function of the jog dial 4 is changed to the display unit for the corneal radius of curvature.

FIG. 6 shows the screen displayed when the mode switch 66 is depressed to change the screen to the corneal size measurement mode. In this mode, a circle is drawn on the screen, and the size on the concentric circle changes centering on the center of the screen upon rotation of the jog dial 4. A scale displayed on the screen also changes. After the eye to be examined is positioned to the center of the screen by the examiner, the jog dial 4 is rotated to align the corneal edge with the size of the circle on the screen. In this case, the size value corresponding to the size of the circle on the screen is displayed as a scale value at the lower left position of the screen. When the corneal edge is aligned with the circle on the screen, the examiner reads the scale value appearing at the lower left position of the screen. On the screen, JG.circleincircle. is displayed, so the examiner can perceptually know that the size of the circle can be changed by rotation of the jog dial 4. The measurement value of this corneal size is printed out at the printer together with other measurement values in measurements of the refracting power and corneal radius of curvature.

FIG. 7 shows the screen obtained when the mode switch 65 is depressed to change the screen to a diaphanoscopy observation mode. Upon diaphanoscopy observation, if the illumination light amount is not properly adjusted, the eye may not be properly observed depending upon the degree of opacity of the crystal of a patient. Therefore, the examiner controls the illumination light amount by rotating the jog dial 4. The screen display in this case becomes "JOG ILLM:120", which indicates to the examiner that the illumination light amount can be changed by rotation of the jog dial 4 and that the current degree of illumination light is 120.

FIG. 8 shows the screen set when the set switch 62 is depressed to obtain a set mode for setting various conditions. In this case, "JOG.uparw..dwnarw.JOY.rarw..fwdarw." is displayed at the lower portion of the screen to indicate the following. When the cursor is to be vertically moved to select an item, the jog dial 4 can be rotated. When the cursor is to be horizontally moved to obtain another setting, the joystick 3 can be rotated. In practice, the main body need not be vertically moved in the set mode. Even if rotation of the joystick is used to set conditions, no practical inconvenience occurs.

FIG. 9 is a view showing a state in which the radius of curvature around the cornea is measured using the keratometer function. This keratometer function mode can be selected by the mode switch 64. This apparatus has eight target lamps (not shown) arranged around a measurement optical system for measurements around the cornea. These target lamps are selectively and properly turned on depending on measurement locations. In this case, a large ring used for aligning the eye to be examined with the apparatus and eight small circles angularly spaced apart from each other and respectively corresponding to the eight target lamps located on a circle inside the large ring are displayed on the screen. A currently ON lamp is indicated in black, while the OFF lamps are indicated in white. In this case, the jog dial 4 can be rotated to select a position at which the corresponding target lamp is turned on. "JOG:FIX.rarw..fwdarw." is displayed to indicate to the examiner that the position at which the corresponding target lamp is turned on can be selected by rotation of the jog dial 4.

FIG. 10 is a view in a message mode. This function is to output a hospital name, a patient's name, and the like. In this case, letters and numbers in the upper portion in FIG. 10 are selected and a measurement switch is depressed to register letters in a lower display space. In this case, the cursor can be moved horizontally with the jog dial 4 and vertically with the joystick 3, thereby quickly shifting the cursor to the letter of interest. In this case, "JOG.rarw..fwdarw.JOY.uparw..dwnarw." is displayed in the lower portion of the screen as opposed to the display in FIG. 8.

FIG. 11 shows the structure of the joystick 3. The joystick 3 comprises an upper lid 31, a measurement switch 32, encoder LEDs 33a and 33b, a rotary encoder scale 34, detection photodetectors (PDs) 35a and 35b, and a main cover 36. The rotary encoder scale 34 is fixed to the main cover 36 and is rotated together with the main cover 36 upon rotation of the main cover 36. The measurement switch 32, the encoder LEDs 33a and 33b, and the detection PDs 35a and 35b are arranged not to be rotated together with the main cover 36. The rotational direction and speed of the main cover can be detected in accordance with the speeds of light pulses incident on the detection PDs 35a and 35b, and a phase difference between the PDs. Outputs from the detection PDs 35a and 35b serve as outputs from the rotary encoder.

FIG. 12 shows the structure of the jog dial 4. The jog dial 4 comprises a rotary encoder scale 41, a photointerrupter 42 integrally incorporating an LED and a PD, and a knob 43. Detection of rotation by the rotary encoder is almost the same as that in the joystick 3.

FIG. 13 is a block diagram showing the overall circuit arrangement. An MPU 80 controls overall operations in accordance with programs stored in a ROM 81. The MPU 80 controls peripheral devices through a data bus 96. A target lamp 85, an autorefracting power measurement source and diaphanoscopy observation light source 87, and a keratometer measurement LED 89 variably control the brightness by controlling the corresponding drivers through D/A converters 84, 86, and 88, respectively. Vertical movement is performed such that rotation of the joystick is detected by a rotary encoder 93 as described above to drive a vertical movement pulse motor 94. Rotation of the jog dial 4 is detected by a jog dial rotary encoder 92 to perform various functions in accordance with a set mode. A VRAM 83 is a bit map memory for displaying a figure on a CRT monitor. Predetermined data is written at a predetermined address in accordance with each set mode under the control of the MPU 80 to display a character, mark, scale, cursor or the like on the screen. The MPU 80 also detects a switch panel 90, a printer 95 for printing out measurement values, and a measurement switch 91 arranged on the joystick.

As in this embodiment, the joystick or the rotary mechanism arranged independently of the joystick performs different operations depending on the set mode, thereby reducing the number of switches and cost. In addition, the user need not operate a large number of switches. The joystick or knob is rotated to select an item from a large number of items or an optimal state of a plurality of continuously changing states, thereby improving operability. In addition, the current function of the rotary mechanism is displayed on the display means arranged in the main body, so that the user can easily confirm the function of the switch, thereby reducing the possibility of erroneous operations.

FIG. 14 is a perspective view showing another embodiment of the present invention. This embodiment is an application to a nonscattering pupil fundus camera. The main body comprises a stationary portion 101 and a movable portion 102 as in FIG. 1. The movable portion 102 has a joystick 103. An illumination light amount change knob 104 is arranged near the joystick 103. In a normal application state, rotation of the joystick is controlled to vertically move a camera portion 108 as in the previous embodiment. Positioning with an eye to be examined is performed while observing a CRT monitor 105. Switches 109 arranged on the front surface of the CRT monitor 105 are used to set various conditions. The knob 104 is controlled to change the observation illumination light amount with its angular position.

FIG. 15 shows the screen in a normal photographing mode. Control items corresponding to the switches 109 are displayed in the lower portion of the screen. FIG. 16 shows the screen in the date setting mode. In this case, the switches 109 are depressed to change any one of the date and time. The knob 104 is rotated to change the numeric value of the selected item. "JOG.uparw..dwnarw." indicates that the function of the knob 104 actually changes numerical values, thereby preventing erroneous operations.

As has been described above, in each embodiment described above, the number of switches can be reduced, easy operation is assured and operability is improved. In addition, a function is displayed on the display means to prevent erroneous operations.