KR101890039B1 - Slit lamp - Google Patents

Abstract

According to the present invention, there is provided an illumination optical system, comprising: an illumination light part including a light source for irradiating measurement light in a slit shape; A reflector for reflecting measurement light irradiated from the illumination light unit and guiding the measurement light to the eye to be examined with fluorescein; An observation optical unit for confirming fluorescence emission light formed in the test piece; A filter module disposed between the light source and the reflector, the filter module having at least one filter; A second filter disposed between the eye to be examined and the observation optical unit, the second filter allowing the fluorescence light to pass therethrough; Wherein one of the filters provided in the filter module is a first filter that transmits light having a wavelength of 450 to 500 nm and blocks light of the remaining band and the second filter transmits light having a wavelength of 500 to 580 nm, Of the slit lamp is blocked, thereby providing a slit lamp capable of increasing the brightness contrast of the fluorescein image of the eye part to be observed at the time of slit lamp inspection.

Description

SLIT LAMP

The present invention relates to a slit lamp, and more particularly, to a slit beam, in which a first filter for transmitting light in the 450 to 500 nm band and for blocking light in the remaining band is provided, 2 filter is configured to transmit light in the 500 to 580 nm band and to block the light in the remaining band, thereby improving the contrast of brightness when observing the fluorescence image of the slit lamp.

Slit lamp is an ophthalmologic instrument that can observe eye tissue sections at high magnification. Slit lamp microscopy can be used for both diagnosis and treatment, and visualization of the anterior ocular structure during stereoscopic viewing is possible and can be expanded in various ways.

Although the light source of such a slit lamp uses white light, various kinds of filters may be used before the slit lamp to adjust the intensity of the light, or to pass only a part of the wavelength, thereby increasing the contrast of the part to be observed.

For example, a cobalt blue filter or a blue filter is used in front of a slit light of a white light in order to observe fluorescein light by using a slit lamp in dry eye inspection or hard contact lens fitting. The light passing through the cobalt blue filter or the blue filter is cut off and the light of a long wavelength passes through only the short wavelength light, and the light touches the eye and the fluorescein substance is emitted to emit green light. Accordingly, the examiner can observe the light to diagnose the eye condition of the examinee or check the fitting state of the hard contact lens.

At this time, the cobalt blue filter or the blue filter to be used is a color filter having a wavelength range of 390 to 410 nm where the transmittance is maximized in the transmission spectrum, and the Gaussian distribution is shown at the peak of the maximum peak. As shown in Fig. 1, the wavelength range at which the absorption rate of fluorescein is maximized is approximately 485 to 500 nm from the absorption and emission spectrum of fluorescein.

In this way, the maximum transmission wavelength of the cobalt blue filter is different from the maximum absorption wavelength of fluorescein. Due to this difference, the overlapping portions of the two spectra are reduced, and the absorption light of fluorescein is decreased, It weakens. Particularly, when image capture is performed on a site to be observed, the fluorescein absorption light and the fluorescein light can not be distinguished from each other. In order to increase brightness contrast, fluorescein observation and image capture were performed on cornea using various types of blue filters having a maximum transmission wavelength ranging from 420 nm to 465 nm, but the results have not been greatly improved.

Alternatively, if a color filter having a wavelength in the range of 485 to 500 nm that maximizes the transmittance is used, the contrast of light increases because the light incident on the cornea and the light absorbed by fluorescein overlap each other. However, The light emitted by the lens is superimposed and the brightness contrast is lowered. As a result, the overall brightness contrast is not greatly improved.

On the other hand, some of the rays passing through the cobalt blue filter or blue filter are absorbed by fluorescein, while others are reflected from the cornea. At this time, the reflected light is mixed with the fluorescein light to lower the brightness contrast. To compensate for this, a yellow filter (Ratten No. 12: Wratten 12) is placed in front of the slit lamp microscope to block light reflected from the cornea. This yellow filter is a filter that is placed in front of the microscope, blocking the blue light that is transmitted through the green light of the fluorescein but is reflected from the corneal surface, which makes the fluorescein more visible to the examiner when used with the cobalt blue filter. However, in such a process, there is a problem that a part of the fluorescence emission light is blocked together.

Korean Patent Registration No. 10-1583284 Korean Patent Publication No. 10-2006-0058005

SUMMARY OF THE INVENTION It is an object of the present invention to provide a slit lamp capable of increasing the contrast of brightness when observing the slit lamp.

According to an aspect of the present invention, there is provided an illumination apparatus comprising: an illumination light part including a light source for emitting a measurement light in a slit shape; A reflector for reflecting measurement light irradiated from the illumination light unit and guiding the measurement light to the eye to be examined with fluorescein; An observation optical unit for confirming fluorescence emission light formed in the test piece; A filter module disposed between the light source and the reflector, the filter module having at least one filter; A second filter disposed between the eye to be examined and the observation optical unit, the second filter allowing the fluorescence light to pass therethrough; Wherein one of the filters provided in the filter module is a first filter that transmits light having a wavelength of 450 to 500 nm and blocks light of the remaining band and the second filter transmits light having a wavelength of 500 to 580 nm, The light of the slit lamp is blocked.

According to a preferred aspect of the present invention, the first filter includes a first substrate, a second substrate formed by alternately laminating a plurality of Ti ₃ O ₅ (titanium oxide) thin films and SiO ₂ (silicon dioxide) thin films on the first substrate, And a first long wavelength transmission filter portion formed by alternately laminating a smaller number of Ti ₃ O ₅ thin films and SiO ₂ thin films on the lower surface of the first substrate than the first short wavelength transmission filter portion, The second filter includes a second substrate, a second short wavelength transmission filter portion formed by alternately laminating a plurality of Ti ₃ O ₅ thin films and a SiO ₂ thin film on the upper surface of the second substrate, and a second short wavelength transmission filter portion formed on the lower surface of the second substrate, And a second long wavelength transmission filter portion formed by alternately stacking a larger number of Ti ₃ O ₅ thin films and SiO ₂ thin films than the transmission filter portion.

According to a preferred aspect of the present invention, the first filter has a wavelength of transmittable light of 300 to 500 nm and a wavelength of transmittable light of 450 nm to 700 nm in the first long wavelength transmittance filter portion, 2 filter may have a wavelength of transmittable light of 300 to 580 nm and a wavelength of transmittable light of the second long wavelength transmittable filter portion of 500 to 700 nm.

According to a preferred aspect of the present invention, the first filter has 23 layers in total, the number of layers of the first short wavelength transmit filter portion is 23, the number of layers of the first long wavelength transmit filter portion is 17 layers, and the second filter has the second short wavelength transmittance The total number of laminated layers of the filter portion is 20 and the number of layers of the second long wavelength transmission filter portion is 26 in total.

According to a preferred aspect of the present invention, the first filter has a physical thickness of 2238 nm +/- 1, the physical thickness of the first long wavelength transmission filter portion is 838 nm +/- 1, The physical thickness of the short wavelength transmission filter portion may be 1951 nm +/- 1 and the physical thickness of the second long wavelength transmission filter portion may be 1503 nm +/- 1.

According to a preferred aspect of the present invention, the filter module includes: a first body having a rotation axis formed on the upper and lower surfaces thereof and coupled to the housing provided with the light source so as to be tiltable right and left; A handle protruding from a front surface of the first body; A second body formed to extend in a fan shape on a rear surface of the first body; And a plurality of filters disposed at positions spaced radially from each other on an upper surface of the second body; . ≪ / RTI >

At this time, the first body is provided with a through hole, and a pair of fixed balls coupled to both ends of the spring are installed to protrude through the upper and lower surfaces of the first body to the through hole, A plurality of grooves are formed in the housing at intervals corresponding to the intervals of the filters and the fixing balls are inserted into one of the coupling grooves when the first body is tilted to set the exact position of the filter module.

According to the slit lamp according to the embodiment of the present invention, the first filter that transmits light in the wavelength range of 450 to 500 nm when the light source is excited and blocks the other light rays is used, and a lot of light passing through the first filter is irradiated with fluorescein And a second filter that transmits light in a wavelength range of 500 to 580 nm and blocks the other rays is installed in the passage region of the light reflected by the subject to detect the light reflected from the cornea except for the fluorescein light It is possible to increase the brightness contrast of the fluorescein image of the eye part to be observed at the time of slit lamp inspection.

1 is a graph showing excitation and emission spectra of fluorescein according to wavelengths.
2 is a side view schematically showing a slit lamp according to an embodiment of the present invention.
FIG. 3 is a perspective view schematically showing the filter module of FIG. 2. FIG.
4 is a cross-sectional view showing the main part of Fig.
5 is a side view of Fig.
6 is a cross-sectional view illustrating a laminated structure of a first filter according to an embodiment of the present invention.
FIG. 7 is a plan view schematically illustrating the second filter of FIG. 2. FIG.
8 is a cross-sectional view illustrating a stacked structure of a second filter according to an embodiment of the present invention.
9 is a graph showing a transmittance spectrum of the first short-wavelength transmit filter unit according to an embodiment of the present invention.
FIG. 10 is a graph showing a transmittance spectrum of the first long wavelength transmission filter portion according to an embodiment of the present invention.
11 is a graph showing a transmittance spectrum of a first filter according to an embodiment of the present invention.
FIG. 12 is a graph showing a transmittance spectrum of a second short-wavelength transmit filter unit according to an embodiment of the present invention.
13 is a graph showing the transmittance spectrum of the first short-wavelength transmit filter unit according to an embodiment of the present invention.
14 is a graph showing a transmittance spectrum of a second filter according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the following embodiments. In addition, to include an element throughout the specification does not exclude other elements unless specifically stated otherwise, but may include other elements.

In this embodiment, for convenience of description, the direction in which the first short-wavelength transmit filter section is positioned is defined as the upper side and the direction in which the first long wavelength transmit filter section is positioned is defined as the lower side.

The slit lamp of the present embodiment is a device used for a slit lamp microscope test for evaluating the health status of the front part of the eye including the eyelid, the conjunctiva, the cornea, the anterior chamber, the pupil, and the lens in the ophthalmology.

A slit lamp microscope examines the light through the lens after passing through the eyes, and the doctor checks the eyes of the examinee's eyes for any abnormality. Particularly, to check for dryness of the eye, flouresin is injected into the eye, and then the eye is blinked, and the whole eye is covered with fluorescein, and then the image is observed.

The light consists of various wavelengths and components, allowing only the light emitted by fluorescein to enter the doctor's eye, filtering out the light that is not used to illuminate the fluorescein, allowing the fluorescein image to be brighter, It is necessary to be able to more effectively check whether there is an abnormality.

Referring to FIG. 2, the slit lamp 100 of the present embodiment includes an illumination light unit having a light source 10, a slit-shaped measurement light irradiated from the light source, and reflects the measurement light to the eye E coated with fluorescein. An observation optical section 70, a filter module 50, and a second filter 60. The first filter 60 includes a first filter 60,

The illumination light part may include a slit part (not shown) having at least one slit for converting the cross section of the measurement light into a slit shape, and a light source 10 for irradiating measurement light toward the slit part. At this time, the light source 10 may be, for example, a halogen lamp, but the present invention is not limited thereto. In addition, the Beam irradiation angle of the light source 10 is preferably 90 [deg.] With respect to the bottom, but this angle can be changed if necessary.

In addition, the illumination light unit may further include a slit adjusting unit (not shown) and a click stop (not shown). The slit adjuster adjusts the length and width of the slit, and the click stop changes the position of the reflector 20 due to a change in the angle of the beam. When the reflector 20 is within the click stop, the focal point of the slit beam coincides with the focal point of the observation portion 70. [

The observation unit 70 serves to confirm the fluorescein image visually by the fluorescence emission light formed on the eye E and may include an objective lens (not shown) and an eyepiece (not shown). At this time, the eyepiece can be compensated for refractive error of the examiner, the distance between the eyepieces can be changed, and can be adjusted, for example, to the examiner's PD. Generally, the angle of the lens in the observation section 70 is set to be straight with respect to the cornea of the examinee, but can be variously changed if necessary. In addition, the observation unit 70 may be provided with one of zoom systems such as stepwise fashion or continuous fashion as necessary to enable magnification.

Further, the slit lamp of the present embodiment may further include the position adjusting member 30. [ The position adjusting member 30 may include a joystick and a handle (not shown) provided at a lower portion of the apparatus. Thus, the examiner can adjust the horizontal movement of the light source 10 using the joystick, and adjust the height of the observation section 70 using the handle, thereby more accurately focusing the image seen by the observation section 70. On the other hand, reference numeral 40 denotes a face supporting member which supports the face of the examinee when the examinee's chin is examined.

On the other hand, when observing the cornea, it is necessary to vary the shape and properties of the slit beam introduced from the light source depending on the situation. For this reason, on the path through which the measurement light irradiated from the light source 10 passes, In this embodiment, a filter module 50 is disposed between the light source 10 and the reflector 20.

3 to 5, the filter module 50 includes a first body 51 having a rotation shaft 59 formed on its upper and lower surfaces, a handle 52 protruding from the front surface of the first body 51, And a plurality of filters disposed on the upper surface of the second body 53 and the second body 53, respectively, which are radially spaced apart from each other. The filter may include a first filter 54, a green / red-free filter 55, a polarizing filter or a neutralization filter 56, which will be described later, Other types of filters may be added in addition to the filter described above except for a part excluding the filter 54. [

The green / red-free filter 55 has the effect of increasing the difference in contrast when viewing the corneal blood vessels. The use of this green / red-free filter 55 allows for a better view of Rose Bengal Staining. The polarizing filter 56 has an effect of reducing undesired specular reflection and making it possible to see fine changes easily. On the other hand, reference numeral 57 denotes a transparent glass which transmits white light as it is and can be used when no separate filtering is required.

The filter module 50 thus constructed is coupled to the housing 11 provided with the light source so that the second body 53 is located on the beam path of the light source 50 and the tilting Lt; / RTI > Therefore, whenever the inspector holds the handle 52 and rotates the first body 51 to the left or right by a predetermined angle, one of the filters provided in the second body 53 passes through the measurement light of the light source 10 It is located on the path and the function of the filter is applied.

A pair of fixing balls 58 coupled to both ends of the spring 58a are formed on the upper and lower surfaces of the first body 51 in the through- So that a part thereof can be protruded from each other. At this time, the housing 11 to which the filter module 50 is coupled is formed with a plurality of coupling grooves 11a and 11b at upper and lower surfaces corresponding to the pair of fixing balls 58 at predetermined intervals corresponding to the intervals of the filters . When the first body 51 is rotated to the left or right, the fixed ball 58, which is compressed by the spring 58a, is inserted into one of the coupling grooves 11a and 11b, In order to be able to be placed in position. At this time, the engaging grooves 11a and 11b can be preferably arc-shaped so as to facilitate insertion or removal of the fixing ball 58 so that the inspector can rotate the first body 51 with a slight force .

Hereinafter, the first and second filters applied to the present embodiment will be described in more detail.

Referring to FIG. 1, the fluorescence emission light has a maximum transmittance in a wavelength range of 485 to 500 nm at the time of excitation, and a wavelength range of 500 to 580 nm at the emission region. Accordingly, the first filter through which the measurement light irradiated from the light source passes through the slit portion and the second filter installed through the portion through which the fluorescein optical image formed in the subject are designed can be designed as follows to optimize the brightness contrast of the fluorescein light have.

The first filter 54 passes measurement light irradiated from the light source 10 toward the reflecting mirror 20. Referring to FIG. 6, the first filter 54 includes a first substrate 54a, a first short-wavelength transmitting filter portion A1 disposed on the top surface of the first substrate 54a, And a first long wavelength transmission filter portion A2 disposed therein. In this embodiment, the first short wavelength transmit filter portion A1 and the first long wavelength transmit filter portion A2 are not formed symmetrically with respect to each other. At this time, the first substrate 54a may be a BK7 glass (borosilicate glass) substrate, but the present invention is not limited thereto.

The first short wavelength transmission filter portion A1 transmits light having a wavelength of 500 nm or less. The first short wavelength transmittable filter portion A1 is an absorptive thin film for attenuating transmitted light. The high refractive index thin film Ti ₃ O ₅ (54b) (titanium oxide) and the low refractive index thin film SiO ₂ 54b (silicon dioxide) 23 layers may be laminated, and the physical thickness of the laminated 23 layers may be about 2238 nm. In addition, the lamination of a thin film Ti ₃ O ₅ thin film (54b) and a SiO ₂ thin film (54b) may be formed in one of a vacuum deposition method, a sputtering method and an ion plating method, but the invention is not limited to this.

Ti ₃ O ₅ TiO ₂ is compared to the (titanium dioxide), inexpensive and Ti ₃ O ₂ in the reaction gas O ₅ There is almost no change in the degree of vacuum during coating and there is an advantage that sparks do not occur when the electron beam is irradiated onto Ti ₃ O ₅ , which is stable.

The first long wavelength transmission filter section (A2) transmits light having a wavelength of 450 nm or longer. The first long wavelength transmission filter portion A2 can be formed by alternately stacking 17 layers of the high refractive index thin film Ti ₃ O ₅ (54b) and the low refractive index thin film SiO ₂ 54c. At this time, May be about 838 nm.

Therefore, the first filter 54 transmits only light in the 450-500 nm wavelength region, which is the region of fluorescein absorption light, and blocks visible light, so that a large amount of light passing through the first filter 54 So that it can act to absorb the fluorescein image adsorbed on the eye. The first filter 54 of the present embodiment can replace the cobalt blue filter or the blue filter used in conventional slit lamps and can provide a better brightness contrast effect than the conventional cobalt blue filter.

7 and 8, the second filter 60 is disposed between the eye to be examined E and the observation optical section 70, The luminescent light passes through. The second filter 60 may further include a body 64 and a disengaging handle 65 protruding to one side of the body 64 for engaging the slit lamp. On the other hand, the second filter 60 can be combined in the form of a push-button switch in which the mounting state is changed to on / off each time the housing 60 is pressed on the housing of the observation optical unit 70, When checking the image of the eye to be examined E with the unit 70, it is possible to adjust so that the second filter 60 is applied or not applied according to the pressing operation.

The second filter 60 includes a second substrate 61, a second short wavelength transmitting filter portion B1 disposed on the upper surface of the second substrate 61, and a second short wavelength transmitting filter portion B1 disposed on the lower surface of the second substrate 61, And a transmission filter unit B2. In the present embodiment, the second short wavelength transmit filter portion B1 and the second long wavelength transmit filter portion B2 are not formed symmetrically with respect to each other. At this time, the second substrate 61 may be a BK7 glass substrate, but the present invention is not limited thereto.

The second short wavelength transmission filter unit (B 1) transmits light having a wavelength of 580 nm or less. The second short wavelength transmission filter unit B1 may be formed by alternately laminating 20 layers of the high refractive index thin film Ti ₃ O ₅ 62 and the low refractive index thin film SiO ₂ 63, Can be about 1951 nm.

The second long wavelength transmission filter portion B2 transmits light having a wavelength of 500 nm or longer. The second long wavelength transmission filter portion B2 can be formed by alternately stacking 26 layers of the high refractive index thin film Ti ₃ O ₅ 62 and the low refractive index thin film SiO ₂ 63, May be about 1503 nm.

Therefore, the second filter 60 transmits only the light in the 500-580 nm wavelength range, which is the fluorescein emission region, and blocks visible light, and blocks most of the light reflected from the cornea except fluorescein light So that it is possible to effectively observe the image of the part to be observed by the eye. The second filter 60 of the present embodiment can replace the yellow filter used in the conventional slit lamp and can obtain a better brightness contrast effect when the fluorescence is observed compared to the conventional yellow filter.

As described above, in the slit lamp to which the first filter 54 and the second filter 60 of the present embodiment are applied, part of the light rays passing through the cobalt blue filter or the blue filter in the conventional slit lamp is reflected by the cornea, It is possible to prevent the brightness contrast from being lowered while being mixed and to prevent the effect of the slit lamp from being deteriorated by blocking a part of the fluorescence emission light by the yellow filter in the conventional slit lamp.

Method of designing first and second filters

The first and second filters applied to the present invention can be designed through the following process.

)를 사용하여 각각 증착한다. 이때, BK7 유리 기판은 알코올 및 아세톤이 혼합된 용액으로 먼저 세척하고, 증착시 온도는 할로겐램프를 사용하여 270℃로 설정한다. 또한, Ti₃O₅박막과 SiO₂박막의 균일도를 유지하기 위해 BK7 유리 기판은 20RPM으로 회전시킨다. 또한, Ti₃O₅를 코팅할 때 O₂ 가스를 공급하고 이때 Ti₃O₅박막의 증착율(deposition)은 3.0A/sec로 설정하고 코팅 중 작업진공도는 1.3×10⁴ torr로 설정하며, SiO₂박막의 증착율은 9.0A/sec로 설정하고 코팅 중 작업진공도는 2.0×10⁵ torr로 설정한다.First, the transmittances of the substrate, the Ti ₃ O ₅ thin film and the SiO ₂ thin film are obtained, respectively. For this purpose, a TiO _{3 5} thin film and a SiO ₂ thin film of about 800 nm thickness are formed on a BK7 glass substrate by electron beam evaporation (elecctron beam evaporation, Saehan, 1200

), Respectively. At this time, the BK7 glass substrate is washed first with a mixed solution of alcohol and acetone, and the temperature during deposition is set to 270 DEG C by using a halogen lamp. In order to maintain the uniformity of the Ti ₃ O ₅ thin film and the SiO ₂ thin film, the BK7 glass substrate is rotated at 20 RPM. Also, when Ti ₃ O ₅ is coated, O ₂ gas is supplied. At this time, the deposition rate of the Ti ₃ O ₅ thin film is set to 3.0 A / sec. The working vacuum degree during coating is set to 1.3 × 10 ⁴ torr. The deposition rate of the _2- thin film is set to 9.0 A / sec and the working vacuum degree during coating is set to 2.0 × 10 ⁵ torr.

Under these conditions, the transmittance of the BK7 glass substrate and the transmittance of the Ti ₃ O ₅ thin film and the SiO ₂ thin film coated on the substrate were measured using a spectrophotometer, respectively, and then the envelope (envelope) The optical constants of the Ti ₃ O ₅ thin film and the SiO ₂ thin film according to the wavelength are obtained by using the curve method. A first filter through which light in a wavelength band of 450 to 500 nm is transmitted and a second filter through which light in a wavelength range of 500 to 580 nm pass through are designed by optical thin film design software (Essential Macleod) using the optical constants thus obtained.

The first filter

The first filter includes a first short wavelength transmission filter portion disposed on the top surface of the first substrate and transmitting light having a wavelength of 500 nm or shorter and a first long wavelength transmission filter portion disposed on the bottom surface of the first substrate for transmitting light having a wavelength of 450 nm or longer And transmits light having a wavelength of 450 to 500 nm.

The optical constants of the Ti ₃ O ₅ thin film obtained by the envelope method are as follows: the refractive index in the visible light region is 2.25 to 2.50; the extinction coefficient is as small as about 0.001 at a wavelength of 400 nm; Value, and it becomes 0 at the above. Further, the refractive index of the SiO ₂ thin film is 1.44 to 1.46 in the visible light region, and the extinction coefficient is 0 in the visible light region. By using these numerical values, a first short-wavelength transmit filter section for transmitting light of a wavelength of 300 to 500 nm and a first long-wavelength transmit filter section for transmitting light of a wavelength of 450 nm to 700 nm are designed.

The design of the first short wavelength transmission filter portion uses a multilayer thin film such as (0.5LH0.5L) ^{N by} repeating the symmetry structure of (0.5LH0.5L) with the fundamental period. Table 1 shows the results of optimization by setting the wavelengths of 300 to 500 nm to transmit and the wavelengths of 500 to 700 nm to be blocked. As shown in Table 1, the first short-wavelength transmit filter portion of the present embodiment is formed by laminating a total of 23 layers on a BK7 glass substrate alternately with a high refractive index thin film Ti ₃ O ₅ and a low refractive index thin film SiO ₂ , The thickness is about 2238 nm. Here, the odd-numbered layer is a Ti ₃ O ₅ thin film and the even-numbered layer is a SiO ₂ thin film.

Layer Optical thickness
Thickness) (QWOT) Physical Thickness
Thickness) (nm) One 1.246395 84.09 2 1.240063 131.53 3 1.494639 100.84 4 1.279629 135.73 5 1.010162 68.15 6 1.112969 118.05 7 1.050935 70.9 8 1.600814 169.8 9 1.242536 83.83 10 1.079819 114.54 11 0.929524 62.71 12 1.002666 106.35 13 1.250443 84.36 14 1.619511 171.78 15 1.072323 72.35 16 1.032759 109.55 17 0.932867 62.94 18 0.959036 101.73 19 0.887968 59.91 20 0.976096 103.54 21 0.930112 62.75 22 0.967735 102.65 23 0.886994 59.84 Total thickness 25.805999 2237.91

9 shows the results of the computer simulation of the first short wavelength transmission filter portion formed according to Table 1. Referring to FIG. 9, the transmittance of the first short wavelength transmittable filter portion is about 4% at a wavelength of 300 nm. When the wavelength increases, the transmittance tends to increase, decrease, then increase and decrease again. . Also, the transmittance of the first short wavelength transmittance filter portion is maintained at about 100% from 420 nm to 500 nm, and then sharply decreases from 500 nm to close to 0 at about 515 nm, thereby blocking light in the longer wavelength region. Therefore, the first short-wavelength transmit filter portion of this embodiment shows a spectrum transmitting light having a wavelength of 500 nm or less. At this time, blocking the light at a wavelength of 515 nm or more serves to prevent the light incident on the cornea from mixing with the fluorescein light to lower the brightness contrast.

The design of the first long wavelength transmission filter section uses a multilayer thin film such as (0.5HL0.5H) ^{N by} repeating the symmetry structure of (0.5HL0.5H) with the fundamental period. Table 2 shows the results of optimization by setting the wavelengths of 450 to 700 nm to transmit and the wavelengths of 300 to 450 nm to be blocked. As shown in Table 2, the first long-wavelength transmit filter portion of the present embodiment is formed by laminating 17 layers alternately on the BK glass substrate with the high refractive index thin film Ti ₃ O ₅ and the low refractive index thin film SiO ₂ , Is about 838 nm. Here, the odd number layer is a DJTi ₃ O ₅ thin film, and the even number layer is a DJSiO ₂ thin film.

Layer Optical thickness
Thickness) (QWOT) Physical Thickness
Thickness) (nm) One 0.565006 29.06 2 0.5195 43.41 3 0.785733 40.41 4 0.765628 63.98 5 0.69321 35.65 6 0.822902 68.77 7 0.588195 30.25 8 0.897688 75.02 9 0.667404 34.33 10 0.872176 72.89 11 0.659769 33.93 12 0.766326 64.04 13 0.745281 38.33 14 0.814908 68.1 15 0.674942 34.71 16 0.808723 67.58 17 0.724284 37.25 Total thickness 12.371672 837.71

10 shows the results of the computer simulation of the first long-wavelength transmission filter portion formed according to Table 2. FIG. Referring to FIG. 10, the transmittance of the first long-wavelength transmittance filter portion is about 100% transmitted from a wavelength of 450 nm to 590 nm, but is reduced by about 8% at a wavelength between 590 nm and 700 nm. The transmittance of the first long wavelength transmittance filter portion increases from 20% at a wavelength of 300 nm to 60% at a wavelength of about 307 nm, and decreases with increasing wavelength, to 8% at a wavelength of about 315 nm, Increases again and then decreases to 0 at a wavelength of 325 nm. Further, light is almost shut off at 325 to 425 nm, and the transmittance steeply increases from 425 nm to 450 nm. Therefore, the first long wavelength transmit filter portion of this embodiment shows a spectrum transmitting light having a wavelength of 450 nm or longer. At this time, blocking the light at 325 to 425 nm causes a large part of the light incident on the cornea to be absorbed by fluorescein.

11 is a graph showing a combination of the transmittance spectrum of the first long wavelength transmit filter portion and the transmittance spectrum of the first filter transmitting light in the wavelength range of 450 to 500 nm in the first short wavelength transmit filter portion of this embodiment. Therefore, when the first short wavelength transmission filter portion is disposed on the upper surface of the first substrate and the first long wavelength transmission filter portion is disposed on the lower surface of the first substrate, A filter can be manufactured.

Thus, when the first short wavelength transmission filter portion and the first long wavelength transmission filter portion are optically synthesized, a common portion of the transmittance of the two filter portions remains, and the magnitude of the transmittance of the synthesized filter portion becomes equal to the transmittance of the two filter portions. However, referring to FIG. 11, two small peaks can be seen in the wavelength range of 300 to 325 nm, but these peaks are small in size and thus have little effect on contrast.

11, the transmittance at a wavelength of 450 to 500 nm is about 98%, the transmittance at a wavelength range of 325 to 425 nm and the wavelength range of 520 to 700 nm is 0, the transmittance at a wavelength of 430 nm to 450 nm is steeply increased, The transmittance is drastically reduced from 520 nm to 520 nm. That is, since the intensity of absorption spectrum of fluorescein becomes the maximum in the range of 490 to 500 nm, it overlaps with the transmittance spectrum of the first filter which transmits light in the wavelength range of 450 to 500 nm so that the light from the light source to the optical section The brightness contrast of the incident measurement light can be greatly increased.

The second filter

The second filter includes a second short wavelength transmission filter portion disposed on the upper surface of the second substrate for transmitting light having a wavelength of 580 nm or shorter and a second long wavelength transmission filter portion disposed on the lower surface of the second substrate for transmitting light having a wavelength of 500 nm or longer And transmits light in a wavelength band of 500 to 580 nm.

Similar to the first filter described above, the second short wavelength transmission filter portion for transmitting light having a wavelength of 300 to 580 nm and the second short wavelength transmission filter portion using the refractive index and the extinction coefficient of the Ti ₃ O ₅ thin film and the SiO ₂ thin film, The second long wavelength transmission filter portion is designed.

The design of the second short wavelength transmission filter portion uses a multilayer thin film such as (0.5LH0.5L) ^{N by} repeating the symmetry structure of (0.5LH0.5L) with the fundamental period. Table 3 shows the results of optimization by setting the wavelengths of light of 300 to 580 nm to transmit and blocking the light of wavelengths of 580 to 700 nm. As shown in Table 3, the second short-wavelength transmit filter portion of the present embodiment is formed by stacking 20 layers of alternately high refractive index thin film Ti ₃ O ₅ and low refractive index thin film SiO ₂ on a BK7 glass substrate, The thickness is about 1951 nm. Here, the odd-numbered layer is a Ti ₃ O ₅ thin film and the even-numbered layer is a SiO ₂ thin film.

Layer Optical thickness
Thickness) (QWOT) Physical Thickness
Thickness) (nm) One 1.29012 97.2 2 0.999577 117.38 3 1.041347 78.46 4 1.062973 124.82 5 0.970299 73.1 6 0.984844 115.65 7 0.990054 74.59 8 1.029307 120.87 9 0.949011 71.5 10 0.989138 116.15 11 0.980413 73.87 12 1.011656 118.8 13 0.955987 72.03 14 0.994531 116.78 15 0.975913 73.53 16 1.007741 118.34 17 0.976929 73.6 18 1.000573 117.49 19 0.974808 73.44 20 1.04672 122.91 Total thickness 20.231937 1950.51

12 is a graph showing the results of computation of the second short wavelength transmission filter portion formed according to Table 3. FIG. Referring to FIG. 12, the transmittance of the second short-wavelength transmitting filter portion starts from 40% at a wavelength of 300 nm, increases slightly, then decreases and then increases and decreases again to about 55% at 360 nm and then decreases to a wavelength of 365 nm 20%, and then increased again to 87% at a wavelength of 380 nm. As the wavelength increases, it decreases and increases repeatedly, and becomes 100% at a wavelength of 470 nm. Further, the transmittance of the second short wavelength transmittable filter portion becomes almost 100% at a wavelength of 470 nm to 580 nm, sharply decreases at a wavelength of 580 nm, becomes almost 0 at a wavelength of 610 nm, and blocks light in a wavelength of 610 to 700 nm. At this time, the blocking of light at a wavelength of 610 to 700 nm serves to pass only light emitted from fluorescein to a second filter having a transmission band of 500 to 580 nm.

The design of the second long wavelength transmission filter section uses a multilayer thin film such as (0.5HL0.5H) ^{N by} repeating the symmetry structure of (0.5HL0.5H) with the fundamental period. Table 4 shows the results of optimization by setting the wavelengths of 450 to 700 nm to transmit and the wavelengths of 300 to 450 nm to be blocked. As shown in Table 4, the second long-wavelength transmit filter portion of the present embodiment is formed by alternately stacking 26 layers of a high refractive index Ti ₃ O ₅ thin film and a low refractive index SiO ₂ thin film on a BK7 glass substrate, The physical thickness is about 1503 nm. Here, the odd-numbered layer is a Ti ₃ O ₅ thin film and the even-numbered layer is a SiO ₂ thin film.

Layer Optical thickness
Thickness) (QWOT) Physical Thickness
Thickness) (nm) One 0.803848 41.34 2 0.632838 52.88 3 0.65094 33.48 4 0.870692 72.76 5 1.076718 55.38 6 1.002205 83.75 7 0.554787 28.53 8 0.808916 67.6 9 1.033575 53.16 10 0.916167 76.56 11 0.740168 38.07 12 0.91299 76.3 13 0.831776 42.78 14 0.941754 78.7 15 0.78395 40.32 16 0.915193 76.48 17 0.736183 37.86 18 0.758783 63.41 19 1.551702 79.81 20 0.544097 45.47 21 0.805654 41.44 22 0.942803 78.79 23 0.778941 40.06 24 0.951753 79.54 25 0.792352 40.75 26 0.935796 78.2 Total thickness 22.274582 1503.42

13 is a graph showing the results of the computation of the second long-wavelength transmission filter portion formed according to Table 4. FIG. Referring to FIG. 13, the transmittance of the second long wavelength transmission filter portion starts from 10% at a wavelength of 300 nm, becomes smaller as the wavelength increases, becomes 0 at a wavelength of about 315 nm, and increases and decreases as the wavelength continues to increase And reaches 0 at 370 nm and reaches 0 at 370 to 485 nm, so that the light is substantially blocked, and the light intensity increases steeply from 485 nm to 500 nm. In addition, the transmittance of the second long wavelength transmittable filter portion becomes almost 100% at a wavelength of 500 to 590 nm, and decreases by 82% at a wavelength of 590 to 700 nm by a maximum of 18%. At this time, the blocking of the light passing through the second long-wavelength transmitting filter portion at the wavelength of 370 to 485 nm is because a large part of the light reflected by the cornea and incident on the second filter is overlapped with the light emitted from the fluorescein, Thereby preventing the deterioration of the image quality.

Fig. 14 is a graph showing a combination of the transmittance spectrum of the second short wavelength transmittable filter portion and the transmittance spectrum of the second filter transmitting light in the wavelength range of 500 nm to 580 nm, which is a composite of the transmittance spectrum of the second long wavelength transmittable filter portion of this embodiment. Referring to FIG. 14, the transmittance of the second filter increases steeply at a wavelength of 490 nm, and becomes about 100% at 500 nm. Also, the transmittance of the second filter is about 99% in the region of the wavelength of 550 to 580 nm, which steeply decreases at 580 nm and becomes 0 at the wavelength of 610 nm. The light is almost shut off from a wavelength of 610 nm to 700 nm.

On the basis of this design, if the second short-wavelength transmitting filter portion is disposed on the upper surface of the second substrate and the second long-wavelength transmitting filter portion is disposed on the lower surface of the second substrate, a second filter for transmitting light in a wavelength range of 500 to 580 nm Can be produced. Thus, when the second short wavelength transmission filter portion and the second long wavelength transmission filter portion are optically synthesized, a portion common to the transmittances of the two filter portions remains, and the magnitude of the transmittance of the synthesized filter portion becomes equal to the transmittance of the two filter portions. However, referring to FIG. 14, two small peaks can be seen in the wavelength range of 300 to 325 nm, but these peaks are small in size and thus have little influence on contrast.
To be more specific, the slit lamp is disposed between the light source and the reflector, and includes a filter module 50 having at least one filter including a first filter 54, and a filter module 50 disposed between the eye to be examined and the observation optical part And a second filter 60 for allowing the fluorescence emission light to pass therethrough. The first filter includes a first substrate 54a, a plurality of high refractive index thin films and a low refractive index thin film on the first substrate 54a, And a low refractive index thin film and a low refractive index thin film are alternately laminated on the lower surface of the first substrate in 17 layers in comparison with the first short wavelength transmitting filter portion. And a long wavelength transmission filter portion.
The second filter 60 includes a second substrate, a second short wavelength transmission filter portion formed by alternately laminating a plurality of high refractive index thin films and a low refractive index thin film on the upper surface of the second substrate, And a second long wavelength transmission filter portion formed by laminating 26 layers of a high refractive index thin film and a low refractive index thin film alternately in comparison with the second short wavelength transmitting filter portion, wherein the high refractive index thin film is a Ti ₃ O ₅ thin film, The refractive index thin film may be a SiO ₂ thin film.
Here, the first filter 54 and the second filter 60 are formed by washing the BK7 glass substrate, which is the first substrate 54a or the second substrate 61, with a solution in which alcohol and acetone are mixed, The temperature was set to 270 DEG C by using a halogen lamp, and the BK7 glass substrate was rotated at 20 RPM in order to maintain the uniformity of the Ti ₃ O ₅ thin film and the SiO ₂ thin film. The deposition rate of the Ti ₃ O ₅ thin film was set to _{3.0 A} / sec The deposition rate of the SiO ₂ thin film was set to 9.0 A / sec. The working vacuum degree during coating was set to 2.0 × 10 ⁵ torr, and the BK 7 glass substrate to 800nm thick Ti ₃ O _5, each depositing a thin film and the SiO ₂ thin film by using an electron beam deposition apparatus, using a spectrometer diagram of the Ti ₃ O ₅ film and the SiO ₂ thin-film coated on the transmittance and the substrate of BK7 glass substrate The Ti ₃ O ₅ thin film and the S The refractive index and the nominal coefficient of the Ti ₃ O ₅ thin film and the SiO ₂ thin film, which were designed by the optical thin film design software using the obtained optical constant, were determined by obtaining the optical constant according to the wavelength of the iO ₂ thin film, It is possible to design the first short wavelength transmission filter portion, the first long wavelength transmission filter portion, the second short wavelength transmission filter portion and the second long wavelength transmission filter portion.
The transmittance of the first short wavelength transmittable filter portion is maintained at 100% from 420 nm to 500 nm, and the transmittance of the first long wavelength transmittable filter portion is maintained at 100% from 450 to 590 to transmit only light in the 450-500 nm band, The transmittance of the second short wavelength transmittable filter portion is maintained at 100% from 470 nm to 580 nm, and the transmittance of the second long wavelength transmittable filter portion is maintained at 100% from 500 to 590, whereby only the light in the 500 to 580 nm band To be transmitted.

The present invention is not limited by the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

100: Slit lamp
10: Light source
11: Housing
11a, 11b: Home
20: reflector
50: Filter module
51: First body
52: Handle
53: Second body
54: first filter
54a: first substrate
54b, 62: Ti ₃ O ₅ thin film
54c and 63: SiO ₂ thin film
58: Fixed ball
58a: spring
59:
60: second filter
61: second substrate
70: observation optical part

Claims (7)

An illumination light part including a light source for irradiating measurement light in a slit shape; A reflector for reflecting measurement light irradiated from the illumination light unit and guiding the measurement light to the eye to be examined with fluorescein; And an observation optics for confirming fluorescence emission light formed in the test piece,
The slit lamp
A filter module disposed between the light source and the reflector, the filter module including at least one filter including a first filter; And
A second filter disposed between the eye to be examined and the observation optical unit to allow the fluorescence light to pass therethrough; / RTI >
The first filter includes a first substrate, a first short wavelength transmission filter portion formed by alternately laminating a plurality of high refractive index thin films and a low refractive index thin film on the upper surface of the first substrate, and a second short wavelength transmission filter portion formed on the lower surface of the first substrate, And a first long wavelength transmission filter portion formed by laminating 17 layers of a small number of high refractive index thin films and a low refractive index thin film alternately in comparison with the transmission filter portion,
The second filter includes a second substrate, a second short wavelength transmission filter portion formed by alternately stacking a plurality of high refractive index thin films and a low refractive index thin film on the upper surface of the second substrate, and a second short wavelength transmission filter portion formed on the lower surface of the second substrate, And a second long wavelength transmission filter portion formed by layering 26 layers of a high refractive index thin film and a low refractive index thin film in a larger number than the transmission filter portion,
The high refractive index thin film is a Ti ₃ O ₅ thin film, the low refractive index thin film is a SiO ₂ thin film,
The first filter and the second filter
The BK7 glass substrate, which is the first substrate or the second substrate, was washed with a mixed solution of alcohol and acetone, and the deposition temperature was set to 270 ° C. using a halogen lamp to maintain the uniformity of the Ti ₃ O ₅ thin film and the SiO ₂ thin film The deposition rate of the Ti ₃ O ₅ thin film was set to 3.0 A / sec, the working vacuum degree during the coating was set to 1.3 × 10 4 torr, the O 2 gas was supplied to the coating, and the deposition rate of the SiO ₂ thin film Was set to 9.0 A / sec. The working vacuum degree during coating was set to 2.0 × 10 ⁵ torr. A 800 nm thick Ti ₃ O ₅ thin film and a SiO ₂ thin film were deposited on a BK7 glass substrate using an electron beam evaporator,
The transmittance of the BK7 glass substrate and the transmittance of the Ti ₃ O ₅ thin film and the SiO ₂ thin film coated on the substrate were measured using a spectrophotometer, respectively, and then the transmittance of the Ti ₃ O ₅ thin film and the SiO ₂ thin film were measured Optical constants are determined and designed in optical thin film design software using the obtained optical constants,
The first and second long wavelength transmittance filter sections, the second short wavelength transmittance filter section and the second long wavelength transmittance filter section are formed by using the refractive index and the nominal coefficient of the Ti ₃ O ₅ thin film and the SiO ₂ thin film obtained by the envelope method, Design,
The transmittance of the first short wavelength transmit filter portion is maintained at 100% from 420 nm to 500 nm and the transmittance of the first long wavelength transmit filter portion is maintained at 100% from 450 to 590 so that only the light in the 450-500 nm band, which is the fluorescein absorption region, ,
The transmittance of the second short wavelength transmittable filter portion is maintained at 100% from 470 nm to 580 nm, and the transmittance of the second long wavelength transmittable filter portion is maintained at 100% from 500 to 590 so that only the light of 500-580 nm band And a slit lamp. delete delete delete The optical filter according to claim 1, wherein the first filter has a physical thickness of 2238 nm +/- 1, the physical thickness of the first long wavelength transmission filter portion is 838 nm +/- 1, Wherein the physical thickness of the filter portion is 1951 nm +/- 1 and the physical thickness of the second long wavelength transmission filter portion is 1503 nm +/- 1. [2] The filter module of claim 1, wherein the filter module comprises: a first body having a rotation axis formed on an upper surface and a lower surface thereof and coupled to the housing provided with the light source so as to be tiltable from side to side; A handle protruding from a front surface of the first body; A second body formed to extend in a fan shape on a rear surface of the first body; And a plurality of filters disposed at positions spaced radially from each other on an upper surface of the second body; Lt; / RTI > [7] The apparatus of claim 6, wherein the first body has a through-hole, and a pair of fixed balls coupled to both ends of the spring are installed in the through-hole so that a part of the through- A plurality of coupling grooves are formed at intervals corresponding to the intervals of the filters in the housing in which the filter module is installed and the fixing balls are inserted into one of the coupling grooves when the first body is tilted, Slit lamp that can be set.

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