JPS5985646A - Eyebottom camera - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Regarding the fundus camera that takes pictures.

In instruments such as fundus cameras that observe the fundus image of the subject's eye, the light beam projected onto the subject's eye through the objective lens is reflected off the corneal surface of the subject's eye, the objective lens surface, etc., and enters the optical path of the observation optical system. There is a problem in that it causes flare or cost in the observed image.

Conventionally, as a means to solve this problem, a ring-shaped slit is placed in the illumination optical system at a position that is conjugate with the pupil of the subject's eye with respect to the objective lens, and a ring-shaped slit is placed behind the objective lens at a position that is conjugate with the pupil of the subject's eye with respect to the objective lens. A perforated mirror with a ring-shaped reflective surface is installed obliquely at a conjugate position, and the projection light beam projected through the ring-shaped slit is once focused on the ring-shaped non-conforming surface of the perforated mirror described above. The image is projected onto the subject's eye through a lens. In the fundus camera of such a device, when the objective lens and the optical axis of the eye to be examined are aligned with each other and the objective lens is at a predetermined distance from the eye to be examined, that is, at an appropriate working distance, the projected light beam is Corneal reflected light can be completely prevented from entering the fitQ optical system.

Therefore, in a fundus camera, the objective lens is placed with its optical axis aligned with the eye to be examined, and
114 It is very important to maintain a positive working distance.

The simplest method for aligning the optical axis of the objective lens of the fundus camera is to use the observation optical system originally equipped with the instrument to observe the pupil of the eye to be examined, and to form an image of the eye to be examined (11iit). The purpose of this is to adjust the position so that it is at the appropriate position ft indicated by an index such as a crosshair or an index frame on the image plane.

However, in an eye ocular instrument for viewing the image in the fundus of the subject's eye, the observation optical system focuses σ near the fundus.
The focusing lens provided in the observation optical system can also be adjusted within the range of 7 to 1 near the fundus of the eye. Therefore, within the adjustment range of the focusing lens, it is not possible to obtain an image of the subject's eye II°; The moving distance in the optical axis direction is 1ξ (F becomes large and is not practical.

In order to solve these problems with fundus cameras,
Special Public Showa 2-'IgdallO No. 1 inserts an auxiliary lens close to the focal point of the objective lens between the objective lens and a perforated mirror, so that the image of the eye to be examined is placed on the focusing glass plate. We are proposing a fundus camera that can form images clearly.

However, because this fundus camera inserts an auxiliary lens between the objective lens and the perforated mirror, the fundus camera becomes large and the operation of inserting the auxiliary lens is complicated. There is a problem in that the illumination light beam reflected by the auxiliary lens surface enters the observation optical system as harmful reflected light, deteriorating the observed image.

As a means to resolve this problem, it is conceivable to further provide a device (l1ζ) for blocking the fundus illumination light flux.

However, if the fundus illumination beam to be examined is blocked, a problem arises in that a separate device for illuminating the eye llii1 to be examined must be provided.

The present invention solves the above-mentioned problems by viewing the 1l7i image of the eye to be examined.

The purpose of this invention is to provide a fundus camera that can be used to visualize fundus images.

The structural features of the present invention include an objective lens disposed facing the subject, an illumination optical system that illuminates the object through the objective lens, and a light beam that passes through the objective lens and directs it to an imaging plane. an observation optical system having a focusing lens for imaging the image;
In order to combine the illumination optical system and the observation optical system described in section 2, the reflection H-71i old model includes a partial reflection section on the opposite side of the eye to be examined with respect to the objective lens. In the fundus camera 1 configured to be able to move the objective lens in the optical axis direction and in a direction perpendicular to this, the distance between the eye to be examined and the objective lens +
:r The auxiliary lens that is inserted into the pupil of the subject's eye and makes the pupil of the subject's eye more beautiful is enclosed in σ.

By configuring the present invention as described above, when the objective lens is sufficiently ν1[1 with respect to the eye to be examined, the illumination light flux υ causes harmful reflected light flux to be generated within the objective lens optical system. An auxiliary lens is automatically inserted into the position, making it possible to observe the pupil of the eye to be examined.

Further, the pupil of the eye to be examined is dilated σ in a dark room, and the fundus of the eye is illuminated with infrared light for observation. Non-mydriatic fundus VC, which does not use a mydriatic agent, does not require a special illumination device for the observation of the pupil of the subject's eye, and uses the illumination light flux for fundus observation of the subject's eye. It has the advantage of being able to

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the optical system of a fundus camera to which the nine studies are applied, which is located in the proper operating path 14 [t, and the optical system includes an observation optical system including a photographing optical system, an illumination optical system, and an index optical system. It has a system.

The observation optical system includes an objective lens 1 placed with respect to the eye E to be examined, an aperture 2 placed near a position conjugate with the pupil E of the eye to be examined with respect to the objective lens l. Auxiliary lenses configured to be able to enter and exit the optical path: 3, focusing lens 4, imaging lens 5, and film 6. Focusing lens 4 and imaging lens 5.
The area between is an afocal optical system. Fundus ER of eye E to be examined
The image is formed on the film 6 by this optical system. An oblique reflecting mirror 23 is provided in front of the film 6, and a lens 24 is disposed on the optical path of the reflecting mirror 23 at a position conjugate with the film 5.Reflecting mirror 2:
The light beam reflected by the field lens 24 and passed through the field lens 24 is imaged by the reflecting mirror 25 and the imaging lens 26 on the photoelectric pole w1 of the image pickup tube 27. The signal from the image pickup tube 27 is sent to the monitor television 28 and displayed on the cathode ray tube screen. form an image.

The illumination optical system includes a diagonal perforated mirror 7 inserted in the optical path of the observation optical system in front of the diaphragm 2, and a lens 1O provided in the reflected optical path of the perforated mirror 7. - IJ link-shaped slint 11, for photographing) °r, flash tube 12. Heat protection filter 13. Consisting of a condensing lens 14 and an observation illumination light source 15, the illumination light from the light source 15 hits the opposite side 11 of the perforated mirror 7 in a ring shape and is reflected, passes through the objective lens 2 and 1lr4Ep of the eye E to be examined. Illuminate the fundus ER.

The index projection system used for focusing in fundus photography consists of a semi-transparent mirror 16, a mirror 11, and a mirror 11. Ryo 17, relay lens 18. The slit 4 is composed of a=;e'i19, a deflection angle lens 20 disposed close to the index 19, a condensing lens 21, and a light source 22.

Light from the light source 22 passes through the condenser lens 21 and illuminates the slit index 19. The slit-like index 19 is shown in FIG.
As shown in 1, slit-shaped indicators 19a, 19(l) provided on the YY' axis and slit-shaped indicators 19b, 19C parallel to the indicators 19a, 19d and provided at the same distance +tilC on both sides thereof. Slit-like indicators 19a, 19b, and 19e.

19, lK are declination angles respectively]0 rhythm 20a, 20b.

20c and 20d are arranged in close contact with each other. The deflection prisms 20a, 20b, 20c, and 20d are shown in FIG.
As shown in b), a in the plane containing the XX' axis.

This gives a declination angle in the b, c, and d directions. This slit transmitted light is transmitted through the relay lens 18 + reflection 'A? t1
7, 1' (+ +Through the aperture 2 and the hole of the perforated mirror 7, a -1-1- image is formed at a position F, which is conjugate with the film 6 with respect to the lens 4.5, and the image is focused through the objective lens l. The light is incident on the optometry r>.

As mentioned above, attach one tip to the deflection prism 20.
The slit-transmitted light, which is divided into iJ and projected symmetrically with respect to the optical axis, is reflected toward the objective lens 1. Therefore, the reflective All-French 16 placed in the optical path of the second observation optical system is
As shown in the figure, there are a number of reflecting parts 1 (3a, 6b) arranged symmetrically on both sides of one optical axis.Therefore,
The reflecting mirror 15 is reflected by the fundus ER,
For the effective light flux of the observation system directed toward In order to
] It has a central aperture hole 2a for a certain luminous flux and diaphragm holes 2b and 2C for the slit-transmitted luminous flux on both sides thereof. moreover.

The perforated mirror 7 also has a hole with projecting portions on both sides so that the light transmitted through the slit passes through the hole.

Fundus ERV - Projection 6 Slit index [In order to increase the contrast of the image, it is desirable to block the background illumination in its projection 'i1 ['J. This day r1~
C5 In this embodiment, a light-shielding plate 9 of a size capable of covering the index image is provided at a position conjugate with the fundus ER of the illumination system and can be freely inserted and removed.

In the optical system shown in FIGS. 1 and 2.

Focusing lens 4. and relay lens 18 of the index projection system, slit index 1≦], declination grism 2 (l condenser lens 21 and lights m and 22 are moved as one in the optical axis direction for focusing, and are focused on the fundus E1. The state of focus on the film (3) can be determined by the state of the slit index image.

According to the above-mentioned procedure, the monitor TV 28 has the seventh
As shown in the figure, an index image superimposed on the fundus image is projected.

The relationship between the in-focus state and the index image is as shown in FIG. In other words, Fig. Indicates the position. Eye) Large (V
On the other hand, when the index image plane moves on the optical axis, the slit-shaped index image 19a' and the index images 19b' and 19C' move in opposite directions. At the time of one focus, the relationship l between the slit-shaped index images 19 b' and 19 a'.

The distance 12 between the slit-like index images 19a' and 19c' becomes equal. That is, l, , 12 are electrically detected, and the direction of movement of the focusing lens hand is determined by the positive or negative of C1, -, t1'2). HL can be detected.

Figure 4 shows 'f) u-examination 111 (an auxiliary lens is inserted into the observation optical system to observe the pupil, and the distance 1η11 between the eye to be examined and the fundus camera is sufficiently larger than the appropriate working distance). FIG. Note that the optical member in FIG. 4 is unchanged from that in FIG. PJ1 except that the auxiliary lens 3 is inserted into the optical path of the observation light Y system.

Since the pupil of the eye to be examined, the pupil E, and the fundus camera are at the position where the working pressure u; Perforated mirror 2 while behind perforated mirror 2
1) Since it is on the II side, the visual field range of the image of the eye 11I'ii to be examined is expanded by 1, and )'r, 11ζ = il, which is convenient for alignment.
You can get the image. On the other hand, since it is sufficiently far from the imaging position of the ring-shaped slit of the illumination optical system, the eye 1 to 11 to be examined is uniformly illuminated to some extent by the illumination light flux.
Jノ] The crab is being eaten. Therefore, monitor television 28
The pupil image 29 of the subject's eye can be observed, and the optical axis of the fundus camera can be easily aligned using the index 30 provided on the screen.

Figures 7 and S show the entire fundus camera.
The two optical systems are housed within the main body 50. The main body 50 is provided with a column 51 that projects downward.
1 has its lower end fully supported by the reciprocating member a52. In order to make it possible to store the main body 50 in the vertical direction, the support column 5
1 includes a guide rod 5 extending downward as shown in FIG.
3 is provided, and the reciprocating table 52 has a guide shaft 54 having a rounded shape for receiving the guide rod 53 and guiding it in the vertical direction.

Further, the column 51 is provided with a threaded rod 55 extending downward, and the threaded rod 55 passes through the cylindrical guide portion 5 (5) provided on the carriage 52. A threaded portion 5 +l a is formed, and this river, threaded portion 5
5aI! It is rotatably supported by a carriage 52 and engaged with a vertical nut 57. An external gear 57a is formed on the nut 57, and this gear 57a is engaged with an external tooth 4158 rotatably supported on the carriage 52 (1) 147. An operation ring 58a that protrudes above the carriage 52 is integrally formed on the external gear 58. With this arrangement, when the operation ring 58a is activated, the support column 51. Therefore, the main body 50 can be prevented from moving in the vertical direction.

A coil spring 51) is arranged around the guide tube 54 and acts between the bottom Vriji of the column 51 and the carriage 52 to support the weight of the fundus camera.

A bearing 60 is arranged at the front of the carriage 52, and this bearing 6
0, a lateral guide rod 61 is slidably and rotatably inserted therein. As shown in g-th (71), wheels 62 are attached to both ends of the guide rod 61, and these wheels 62 are connected to the table 6.
The track 04 J: provided in 8 is arranged so that it rolls! be done.

A plurality of pins 65 are provided at equal intervals on the track 64, and the wheel (52 has holes 6 on its circumference that engage with the bins 05).
2a is formed. The wheel 62 has a hole in the wheel 62 (52
σ is guided along the track 64 by the engagement between a and the pin 65. The guide rod 61 is slidable in the axial direction on the bearing 60, and therefore the carriage 52 is
can be moved laterally along the A locking mechanism (not shown) is provided to fix the carriage 52 on the guide rod 61, and is operated by an operating knob 67 shown in FIGS. 7 and 3.

A raised flat surface 63a is formed at the rear of the table 63, and a spherical part 67a provided at the end of a stick 67 for longitudinal and lateral fine adjustment is rotatably supported at the rear of the carriage 52. , this spherical part 67a has a flat upward surface 63
It's on top of a. Therefore, the height of the carriage 52 is determined by the guide rod 61 at the front and by the spherical section 67 at the rear.
Defined by a. The table 63 includes a microswitch 68 and a pin 6 for operating the microswitch.
9 is provided, and the pin 69 projects downward from the carriage 52''. A forehead rest 71 and a 171'' 4° support 72 for the subject are supported by a support 70 on the front part of the table 63, and the main body 50 has an objective lens 1 which is attached to the subject's eye.
They are positioned to face each other at an appropriate working distance. Main body 5
0 is sent sufficiently backward than the appropriate working distance.
When the switch can move fully backward, the switch actuating pin 69 rides on the flat surface 63a, and the switch 68 is actuated.

Figure 70 shows the σ i1 adopted in the fundus camera of this embodiment.
FIG. 2 is a block diagram of the electrical processing that includes the iυ focusing function.

Monitor the signal obtained by the imaging 'i'i27.
111Σ is sent to 128 to form a visible image.
Although the curve is roughly photographed [the output signal of the elephant tube 26 is 4]
The signal is sent to the one-target image signal detection circuit 80. The output signal of the image pickup tube 26 is a scanning signal, and is shown in FIG.
Index methods 19a', 19b', 19c', 19d' shown in
It also includes 419 bows. Since the index image signal has a high level KF3''>j, which is the highest level in the fundus image, the circuit 80 selects the high level signal to generate the index image signal in the form of a λ value signal, and converts this signal into the index image. The interval comparison circuit 81 is supplied with the signal.

The index image interval comparison circuit 8] calculates the index 1″4:1≦l a′
, l D b' 1 cancer and index images 19a', 19c
' and outputs the difference signal to the control calculation circuit 82.

The control calculation circuit 82 receives the output from the index image interval comparison circuit 81, controls the focusing lens moving motor 83, and moves the focusing lens and the index projection system in the optical axis direction so as to match the index intervals σ to obtain focus.

The control arithmetic circuit 82 is also configured to receive the output of the switch 68, so that the carriage 52 can be moved fully backwards and the objective lens 1 on the main body 50 can be placed at an appropriate operating pressure N6 for the eye E.
When the switch 68 is activated after the camera moves back by a distance l++iI which is more than a predetermined value, the control calculation circuit 82 stops the above-mentioned automatic focusing operation. At this time, the output υ of the arithmetic circuit 82 moves the focusing lens drive motor 83 to a predetermined position (for example.

At the same time, the auxiliary lens 3 is inserted into the optical system of the observation optical system by the auxiliary lens moving means 84.

Since the main body 50 of the fundus camera is moved sufficiently backwards than the appropriate operating pressure +1Jll, a pupil image 29 of the subject's eye shown in FIG. 4 can be obtained on the monitor television 28'2. Optical axis alignment can be easily achieved by appropriately providing the index line 90 on the screen of the monitor television 28. To align the optical axis, operate the operation knob 58a to adjust the main body 50 in the vertical direction, and move the carriage 52 to the guide rod 6.
Do not move left or right along line 1. Fine adjustment of the horizontal movement is performed by tilting the stick 67 left and right and slightly rolling the spherical part (57a).The reciprocating table 52 is fixed on the guide rod 61 by operating the bale and knob 66, and the reciprocating table 52 is fixed on the guide rod 61. Push the table 52 forward. At this time, the first spherical part 67a
a Kick J2. 4 in the hole 62a of the wheel 62 and the track.
When the fundus camera of the main body 50 approaches the proper working distance due to engagement with the soil pin 65, the switch actuating pin 60 comes off the higher flat JJJ surface 63a and the switch 68 opens. At the same time, the auxiliary lens 3 is moved by the auxiliary lens moving means 8 operated by the output of the control circuit 82.
4, it is removed from the optical path of the optical system to '(!'r1.V)'; As a result, it becomes possible to observe the fundus image of the eye to be examined using the observation optical system, and the automatic focusing circuit described above starts operating. For fine adjustment to obtain the appropriate working distance between the eye E and the objective lens 1, use the stick 6.
7 by nodding forward and backward.

In the above, an embodiment has been described in which an auxiliary lens is inserted into the observation optical system in order to enable the observation of the pupil image of the subject's eye with the observation optical system. The i-image does not need to be completely focused, and the purpose can be sufficiently achieved if the image is a recognizable enough image for light 'III alignment. Therefore, if the working distance of the fundus camera is sufficiently larger than the appropriate working pressure,
That is, when the switch '68 is opened, the control calculation circuit stops the automatic focusing operation and the 5 focusing lens 3
By moving the fundus of a highly hyperopic eye to a focusing position (for example, +70 deiono 0 tar position),
It may also be configured to enable observation of 16i images.

As described above, according to the present invention, a manual switch is provided for measuring the pupil of the eye to be examined, and the detection means detects that the working distance of the fundus camera is sufficiently larger than the appropriate value. Since the eye to be examined n (jr) can be automatically viewed, rapid optical axis alignment is possible.

Roughly speaking, infrared light is used for illumination (1.11. In a fundus camera, there is no need to provide separate and independent illumination for illuminating the eye to be examined, and a ring-shaped slit illumination for fundus observation is used. It is possible to observe the subject's pupil using light.The non-mydriatic fundus camera is
Light source for illumination 15. And the light source 22 of the index projection thread is an infrared light source, or a filter that does not transmit visible light and transmits infrared light is used in the optical system of the lens.
What you get by inserting a monkey.

[Brief explanation of the drawing]

Appropriate operating pressure 1iif# where L part 1 light is applied in Figure 1
Figure 2 is a schematic diagram showing an example of the optical system of a single-bottom camera, and Figure 2 is a perspective view showing an example of the arrangement of the focusing index and deflection prism. is shown in Figure 2 (
Plan view of the sign and deflection prism, No. 31, 1 is a combination'! 1J1] is a plan view showing the outline of the J11 projection optical system. This shows the image of the projection index for focusing. Figure S (a) shows the in-focus state, and Figure S (tb) shows the focus position ti.
The state in which 7i is deviated in one direction from 7i is shown in Fig. L, Fig. 4 shows an example of the optical system of the eye angle C camera at the proper working pressure, i, [fx ff jli force fl'l sufficiently thicker than L] #lIl [1llr', IZI-7th The figure is an outline 1 showing the whole of l1lJ, which is an embodiment of the present invention.
F! ! l tlTj diagram, Figure 3 is Figure 71 and ζ shows σAt
Figure 9 is a schematic front view of the fundus camera.
! Figure 70 is an enlarged sectional view showing the mechanism for moving the limbs and the auxiliary lens for moxibustion and pupil observation.
FIG. 2 is a block diagram of an air circuit. 1......"Ij !Lens, 3...
...Auxiliary lens, 4...Focusing lens 19a, 191), 19c...Indicator. 50... Fundus camera body. 51......Strut, 52...Mountain carriage. 61... Guide rod, 63... Table, 63a... Flat surface, 68... Switch Y' Fig. 2 Fig. 3 Figure 5 Figure 5 Figure 5

Claims (1)

[Claims] (1) An objective lens placed facing the subject. An illumination optical system that illuminates through an objective lens. an observation optical system having a focusing lens for focusing the light beam transmitted through the objective lens on an imaging plane; and a side opposite to the subject's eye with respect to the objective lens for combining the illumination optical system and the observation optical system. and a reflecting member partially including a reflecting part, and is moved in the optical axis direction of the objective lens and in a direction perpendicular thereto.
In the fundus camera configured to enable j, the distance 1iff detection means detects that the distance between the eye to be examined and the objective lens is larger than the appropriate working distance by a predetermined value or more. The eye fundus measurement device further includes an auxiliary lens that can be inserted between the reflective member and the imaging plane in response to the operation of the distance detecting means to enable observation of the eye to be examined 111IX. (2. The fundus camera according to claim 1, wherein the illumination optical system is illuminated by red light.