JP2793989B2 - Rotating filter of light source device for endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary filter of an endoscope light source device capable of supplying various illumination lights so that various images having different observation wavelength ranges and the like can be obtained.

[0002]

2. Description of the Related Art In recent years, by inserting an elongated insertion portion into a body cavity, it is possible to observe internal organs in the body cavity or to perform various treatments using a treatment tool inserted into a treatment tool channel as necessary. Endoscopes are widely used.

[0003] Various electronic endoscopes using a solid-state imaging device such as a charge-coupled device (CCD) as imaging means have also been proposed.

[0004] In the case of an endoscope apparatus which picks up an image in a plane-sequential manner, by changing the wavelength range of the plane-sequential illumination light, not only an image for normal observation but also an image in a plurality of specific wavelength ranges or a visible image is obtained. For example, an image in an infrared wavelength region other than the region,
It is possible to obtain a special image for examining a lesion site or the like. In order to change the wavelength region of the illumination light, a plurality of filters having different transmission wavelength regions may be prepared and switched in a rotary filter that separates the illumination light in time series.

[0005] In a normal observation filter,
By using an aperture angle changing type rotary filter in which the aperture angle of a filter that transmits each of the R, G, and B wavelength ranges is changed, for example, when the aperture angle is reduced, R, G, and
An image with less blur is obtained for each color of B. When the aperture angle of each filter of the rotary filter is changed, the aperture angles of each of the R, G, and B filters may be made different from each other in order to obtain a white balance.

By the way, aluminum or the like is used for the frame of the rotary filter, and a material such as glass is used for each filter. However, if the specific gravity of the frame and each filter is different, as described above, If the aperture angles are different, the rotary filter will be unbalanced. As described above, when the unbalanced rotary filter is driven,
The rotation of the filter may not be stable, and the feedback control may not work.

[0007]

As described above, in the conventional configuration, when the opening angle of each filter of the rotary filter is changed, the rotary filter becomes unbalanced and the driving of the rotary filter becomes unstable. There is a risk. When such an unbalanced rotary filter is used, the rotation of the filter is not easily stabilized, and there may be a problem that the feedback control does not work, so that the illumination light of each wavelength region is supplied stably. There is a problem that it is not possible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended for an endoscope capable of providing a stable rotation, a stable rotation, and a stable supply of illumination light in each wavelength region. It is an object of the present invention to provide a rotary filter for a light source device.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a light source device for an endoscope which is provided in a light source device for an endoscope and emits light in different wavelength regions by transmitting white light emitted from the light source. In the rotary filter, a balancer is provided in a part of the rotary filter. With this configuration,
Stable rotation can be obtained when the rotation filter is driven.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 15 relate to an embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of an endoscope device to which a light source device is connected. FIG. 2 is a side view showing the entire endoscope device. 3 is a cross-sectional view of a filter cassette showing a basic configuration of a rotary filter, FIG. 4 is a cross-sectional view taken along line AA ′ of FIG. 3, FIG. 5 is a perspective view of a filter cassette changer,
FIG. 6 is a plan view of the filter cassette changer, FIG. 7 is a perspective view showing the rear side of the filter cassette changer,
FIG. 8 is a cross-sectional view taken along the line BB 'of FIG. 6, FIG. 9 is an explanatory view showing transmission characteristics of each filter of the rotary filter for normal observation, and FIG.
0 and 11 are explanatory diagrams showing the transmission characteristics of each filter of the special image rotating filter, FIGS. 12 and 13 are explanatory diagrams showing changes in blood absorbance due to changes in hemoglobin oxygen saturation, and FIG. FIG. 15 is a cross-sectional view of a filter cassette for illustrating another example of the rotary filter for observation, and FIG. 15 is a cross-sectional view of the filter cassette for illustrating the rotary filter according to the present embodiment.

First, the structure of a light source device to which the present invention is applied will be described with reference to FIGS.

As shown in FIG. 2, an electronic endoscope 1 connected to a light source device has an elongated, for example, flexible insertion portion 2 and a large-diameter operation portion is provided at the rear end of the insertion portion 2. 3 are connected in series. A flexible cable 4 extends laterally from a rear end of the operation unit 3, and a connector 5 is provided at a distal end of the cable 4. The electronic endoscope 1 is connected via the connector 5 to a video processor 6 having a light source device and a signal processing circuit built therein. Further, a monitor 7 is connected to the video processor 6.

On the distal end side of the insertion portion 2, a rigid distal end portion 9 and a bending portion 10 which can be bent rearward and adjacent to the distal end portion 9 are sequentially provided. By rotating a bending operation knob 11 provided on the operation section 3, the bending section 10 can be bent in the left-right direction or the up-down direction. Further, the operation section 3 is provided with an insertion port 12 which communicates with a treatment instrument channel provided in the insertion section 2.

As shown in FIG. 1, a light guide 14 for transmitting illumination light is inserted into the insertion section 2 of the electronic endoscope 1. The distal end surface of the light guide 14 is
, And the illumination light can be emitted from the tip 9. In addition, the light guide 14
Is inserted into the universal cord 4 and connected to the connector 5. In addition, the tip portion 9 includes:
An objective lens system 15 is provided, and a solid-state imaging device 16 is provided at an image forming position of the objective lens system 15. The solid-state imaging device 16 has sensitivity in a wide wavelength range from the ultraviolet region to the infrared region including the visible region. Signal lines 26 and 27 are connected to the solid-state imaging device 16, and these signal lines 26 and 27 are inserted into the insertion section 2 and the universal cord 4 and connected to the connector 5.

On the other hand, the light source device 20 provided in the video processor 6 includes a lamp 21 that emits light in a wide band from ultraviolet light to infrared light. As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and the strobe lamp emit a large amount of ultraviolet light and infrared light as well as visible light. The lamp 21 is supplied with power by a power supply unit 22. In front of the lamp 21, a plurality (three cases are shown in the figure) of filter cassettes 50 are provided. The filter cassette 50 is selectively inserted into an illumination light path by a filter cassette changer 70.
Further, the filter cassette changer 70 is controlled by a control signal from the switching circuit 43. Each filter cassette 50 has a rotary filter 51. When the filter cassette 50 is inserted into the illumination optical path, the rotary filter 51 is connected to the motor 23 and is rotated by the motor 23. The rotation of the motor 23 is controlled by a motor driver 25 to be driven.

The structure of the filter cassette 50 will be described with reference to FIGS.

As shown in FIG. 3, the rotary filter 51 has three filters 51a, 51b and 51c arranged in a circumferential direction. In the case of a rotating filter for normal observation, the filters 51a, 51b, 51c are
Each is a filter that transmits light of each wavelength region of red (R), green (G), and blue (B) as shown in FIG. A plurality of holes 53 for detecting the rotational position of the rotary filter 51 are provided on the inner peripheral side of each of the filters 51a, 51b, 51c.
Are arranged along the circumferential direction. As shown in FIG. 4, the rotary filter 51 includes a filter cassette 5
The rotating shaft 54 of the rotary filter 51 is rotatably supported by ball bearings 55, 55 provided at the center of the housing 52.

Windows 56 and 56 are provided on the front plate 52a and the rear plate 52b of the housing 52 at positions facing each other and with the filters 51a, 51b and 51c of the rotary filter 51, respectively. The light emitted from the light source 21 is transmitted through the windows 56, 56 and the respective filters 51.
a, 51b and 51c can be transmitted. Further, windows 57 and 57 are provided in the front plate 52a and the rear plate 52b at positions facing each other and also facing the holes 53 for detecting the rotational position of the rotary filter 51. A light emitting element 61 is provided outside one window 57, and a photo sensor 62 is provided outside the other window 57. The light emitting element 61 and the photo sensor 62 constitute a rotary encoder 60. ing. That is, the light emitted from the light emitting element 61 and passed through the hole 53 is received by the photo sensor 62, and the output of the photo sensor 62 is input to the timing generator 42 which generates the timing of the entire system. .

The rotary shaft 54 of the rotary filter 51
Project from the rear plate 52b side of the housing 52 to the rear. On the other hand, at the end of the output shaft of the motor 23,
A clutch 64 is provided, and via the clutch 64,
The rotation shaft 54 of the rotation filter 51 and the output shaft of the motor 23 are connected.

At the bottom end of the housing 52 on the side of the filter cassette changer 70, there is provided a claw 65 projecting downward.

As the rotary filter 51, for example, the following special image rotary filter is prepared in addition to the normal observation rotary filter in which filters having transmission characteristics as shown in FIG. 9 are arranged. ing.

One rotation filter is composed of three filters 5
Reference numerals 1a, 51b, and 51c denote rotating filters that transmit a narrow band centered at 805 nm as shown in FIG. 10 (hereinafter referred to as 805-nm single-wavelength rotating filters).

Another rotating filter includes three filters 51.
As shown in FIG. 11, two of the filters a, 51b, and 51c are a filter that transmits a narrow band centered at 500 nm and a rotary filter that transmits a narrow band centered at 650 nm (hereinafter referred to as a filter). Is called a hemoglobin amount observation type rotation filter.).

In still another rotating filter, the wavelength range through which the three filters 51a, 51b, and 51c pass has a wavelength at which the absorbance of blood changes due to a change in the oxygen saturation of hemoglobin (hereinafter also referred to as SO ₂ ). , A rotation filter (hereinafter referred to as SO ₂₎ which is _two wavelengths near the wavelength and in which the change in absorbance of blood due to the change in SO ₂ is small.
It is called an observation type rotation filter. ). FIG.
Shows the change in absorbance of blood (scattered reflection spectrum) due to changes in SO ₂ near 0～650Nm. The transmission wavelength range of each filter of the SO ₂ observation type rotary filter in this band is, for example, 569 nm, 577 n.
The set of m, 585 nm is selected. The combination of the transmission wavelength ranges of the filters of the SO ₂ observation type rotary filter is as follows.
It is not limited to the one shown in FIG. Figure 12 shows the spectral absorption characteristics of oxyhemoglobin and deoxyhemoglobin, as can be seen from this figure, the combination of the transmission wavelength bands of the filters of SO ₂ observations rotary filter, i.e., the oxyhemoglobin and deoxyhemoglobin Several combinations of two wavelength ranges having substantially equal absorbances and wavelength ranges having a large difference in absorbance between oxyhemoglobin and deoxyhemoglobin can be selected.

Still another rotary filter is for normal observation as shown in FIG. 14, but the aperture angles of the R, G and B filters 51a, 51b and 51c are changed (in FIG. An example will be described.) This is a rotating filter (hereinafter, this will be referred to as a variable aperture angle rotating filter).

Each of the various rotary filters 51 is provided with a housing 52 of a separate filter cassette 50.
Is housed inside.

Next, the structure of the filter cassette changer 70 will be described with reference to FIGS.

As shown in FIG. 5, the filter cassette changer 70 includes a cassette unit 71 capable of storing a plurality of (three in the figure) filter cassettes 50. The cassette unit 71 is formed with, for example, three cassette storage portions 72 that are open on the side of the illumination light path indicated by the optical axis 24.
The above-mentioned plural types of filter cassettes 50 are stored. At the bottom of the cassette unit 71, a nut 73 arranged in parallel with the optical axis 24 of the illumination light path is attached. A pipe screw 76 rotated by a cassette change motor 75 is screwed into the nut 73. The motor 75 is fixed at a predetermined position so as not to move. Then, by rotating the pipe screw 76 by the motor 75, as shown in FIG.
1 can be moved back and forth in a direction parallel to the optical axis 24 of the illumination light path.

As shown in FIG. 8, rails 77, 77 are provided in the upper and lower portions of each cassette accommodating portion 72 of the cassette unit 71, and the filter cassette 50 is provided.
Moves along the rails 77 and 77 and is inserted into and removed from the illumination optical path. Further, the pawl 65 of the filter cassette 50 projects downward from the lower rail 77, and one end of the pawl 65
The other end of the tension spring 78 fixed to the back of the second spring 2 is attached. The spring 78 urges the filter cassette 50 in a direction in which the filter cassette 50 is stored in the cassette storage section 72.

As shown in FIG. 7, an elongated hole 80 communicating with all the cassette storage sections 72 and being parallel to the optical axis 24 of the illumination optical path is provided below the surface of the cassette unit 71 on the side opposite to the illumination optical path. Are formed. A pipe screw 82 arranged perpendicular to the optical axis 24 and rotated by a motor 81 is inserted into the elongated hole 80. FIG.
As shown in the figure, a nut 83 is screwed into the pipe screw 82 in the cassette unit 71. The rotation of the nut 83 is restricted, and the nut 83 is moved by the rotation of the pipe screw 82, and abuts on the pawl 65 of the filter cassette 50. The motor 81 is fixed at a predetermined position so as not to move. Then, by rotating the pipe screw 82 by the motor 81, the filter cassette 50 is moved together with the nut 83 so that the filter cassette 50 can be inserted into and removed from the illumination optical path. When the filter cassette 50 is moved in a direction to be retracted from the illumination light path, the filter cassette 50 is retracted by the tension of the spring 78 by retracting the nut 83.

Next, the filter cassette changer 70
Will be described.

First, by rotating the motor 75, the cassette unit 71 is moved so that the desired filter cassette 50 can be moved by the nut 83.
To move. Next, by rotating the motor 81, the nut 83 abutting on the claw 83 of the desired filter cassette 50 is advanced to the illumination light path side, and the filter cassette 50 is pushed out. As a result, as shown in FIGS. 5 and 6, the filter cassette 50 is disposed at a position where the windows 52a and 52b are interposed in the illumination light path. In this state, the clutch 64 provided on the output shaft of the motor 23 for rotating the rotary filter is
Linked to When connecting the clutch 64 and the rotating shaft 54, the motor 23 may be moved to the filter cassette 50 side, or the clutch 64 and the rotating shaft 54 may be connected using a magnet. You may do it.

Next, when the filter cassette 50 is retracted from the illumination optical path, the motor 81 is rotated and the nut 83 is retracted, whereby the filter cassette 50 is retracted by the pulling force of the spring 78, and the cassette accommodating portion is retracted. 72.

As shown in FIG. 1, the light selected by the filter cassette changer 70 and transmitted through the rotary filter 51 of the filter cassette 50 provided in the illumination optical path is condensed by a condenser lens 88 and Guide 1
4 and is guided to the tip 9 via the light guide 14 and emitted from the tip 9 to illuminate the observation site.

The return light from the observation site due to the illumination light is imaged on the solid-state imaging device 16 by the objective lens system 15 and is photoelectrically converted. A driving pulse from a driver circuit 31 in the video processor 6 is applied to the solid-state imaging device 16 via the signal line 26, and reading and transferring are performed by the driving pulse. The video signal read from the solid-state imaging device 16 is input to a preamplifier 32 provided in the video processor 6 or the electronic endoscope 1 via the signal line 27. The video signal amplified by the preamplifier 32 is input to a process circuit 33, subjected to signal processing such as γ correction and white balance, and converted into a digital signal by an A / D converter 34. The digital video signal is supplied by a select circuit 35 to three memories (1) 36a, memories (2) 36b, and memories (3) corresponding to, for example, red (R), green (G), and blue (B).
36c is selectively stored. The memory (1) 36a, the memory (2) 36b, the memory (3)
36c are read out at the same time, converted into analog signals by a D / A converter 37, output as R, G, and B color signals, input to an encoder 38, and output from the encoder 38 as an NTSC composite signal. It has become so.

The R, G, B color signals or N
The TSC composite signal is input to the color monitor 7, and the color monitor 7 displays the observation region in color.

The timing generator 42 synchronizes the motor driver 25, driver circuit 31, select circuit 35, and other circuits.

In this configuration, when the filter cassette changer 70 is controlled by the switching circuit 43 and the filter cassette 50 having the built-in rotary filter 51 for normal observation is interposed in the illumination optical path, the light emitted from the lamp 21 is emitted. Are filters 51a and 5 of the rotary filter 51 for normal observation in the filter cassette 50 that transmit R, G and B.
1b and 51c are sequentially transmitted and divided into light of R, G, and B wavelength regions in a time-series manner. And this R, G, B
Is transmitted to the distal end portion 9 via the light guide 14 and irradiates the subject. R in this visible band,
The return light from the subject due to the G- and B-sequential illumination light is formed on a solid-state imaging device 16 by the objective lens system 15, and the solid-state imaging device 16 captures a subject image. Therefore, a normal visible image is displayed in color on the monitor 7.

On the other hand, when the filter cassette changer 70 is controlled by the switching circuit 43 and a filter cassette 50 having another built-in special image rotary filter 51 is interposed in the illumination optical path, the type of the rotary filter 51 is changed. Accordingly, the following image is obtained.

First, when the 805 nm single-wavelength type rotary filter is selected, the 805 nm
Is transmitted through this rotating filter, and an image of the subject in a narrow band around 805 nm is obtained. By the way, ICG which is an infrared absorbing dye
Blood mixed with (Indocyanine green) has a maximum absorption at 805 nm. Therefore, for example, by mixing the ICG into blood by intravenous injection and observing an image of the subject in a narrow band centered at 805 nm, it is possible to observe cancer of IIb and the running state of blood vessels under the mucosa. Becomes possible.

When a hemoglobin amount observation type rotation filter is selected, an image of a subject in a narrow band around 500 nm and an image of a subject in a narrow band around 650 nm are obtained. As shown in FIG.
There is a large difference in the absorbance of blood between around 00 nm and around 650 nm. Therefore, a change in the amount of hemoglobin can be observed from the difference between the absorbances in the two wavelength ranges.

When the rotation filter of the SO ₂ observation type is selected, images in the respective wavelength ranges of 569 nm, 577 nm and 585 nm are obtained. As shown in FIG.
nm and 585 nm are wavelengths at which the absorbance of blood hardly changes due to the change of SO ₂ , and 577 nm is the wavelength of S
This is the wavelength at which the absorbance of blood changes due to the change in O ₂ . Therefore, the images in these three wavelength ranges show that SO ₂
Changes can be observed.

When an aperture angle changing type rotary filter in which the aperture angle of the filter is reduced is selected, R, G,
An image with less blur is obtained for each of B. still,
The color shift between R, G, and B can be corrected.

When no filter cassette 50 is interposed in the illumination optical path, white light can be output, and an endoscope such as a fiberscope or the like capable of observing the naked eye or a simultaneous imaging means can be used. A suitable illumination light can be supplied to an endoscope having the same.

As described above, according to the above configuration, by switching the filter cassette 50 interposed in the illumination light path by the filter cassette changer 70, a combination of field sequential illumination light is selected from a plurality of combinations. be able to. Therefore, it is possible to supply various combinations of plane-sequential illumination light having different wavelength ranges depending on the observation site, observation purpose, and the like. Then, various images such as a normal image,
It is possible to obtain an image showing a running state of a cancer or a blood vessel, an image showing a change in hemoglobin amount, an image showing a change in oxygen saturation of hemoglobin, and an image with little blur for each of R, G, and B.

Here, the configuration of the rotary filter of this embodiment will be described with reference to FIG.

Each filter 51a, 5 of the rotary filter 51
When the aperture angles of 1b and 51c are changed, the aperture angles of the R, G, and B filters are not equal to each other, for example, as shown in FIG. . In the example shown in this figure, a filter 51a transmitting R is replaced by a filter 51b transmitting another G,
The aperture angle is smaller than that of the filter 51c that transmits B.

The frame 90 of the rotary filter 51 is made of aluminum or the like.
Glass and the like are used for 1b and 51c, but when the specific gravity of the frame body 90 and each of the filters 51a, 51b and 51c are different, as shown in FIG.
If the opening angle of the rotation filter 1c is different,
Becomes unbalanced. As described above, when the unbalanced rotary filter 51 is driven, it is difficult to stabilize the rotation filter 51 and the feedback control may not work.

Therefore, in this embodiment, the rotation filter 5
The balance is achieved by attaching a balancer 91 to a part of one frame body 90. The position and weight of the balancer 91 are set in accordance with the position of the center of gravity of the rotary filter 51 before the balancer 91 is attached. In the example shown in FIG. 15, since the specific gravity of the frame body 90 is larger than the specific gravity of each of the filters 51a, 51b, and 51c, the center of gravity is shifted toward the R transmission filter 51a from the center of rotation. A balancer 91 is mounted on the opposite side. By balancing the rotation filter 51 in this manner, the rotation of the rotation filter 51 rises smoothly and the rotation is stabilized.

The present invention is not limited to the above-described embodiment. For example, the rotary filter 51 may include each filter 51a,
As 51b and 51c, filters provided for transmitting three different wavelength regions in an infrared band or an ultraviolet band may be provided. With such a rotary filter, a subject image in an infrared band or an ultraviolet band can be observed. Also,
Instead of a rotary filter, a filter cassette incorporating a filter that always transmits predetermined light may be provided.

The mechanism for exchanging filter cassettes is not limited to the one shown in the embodiment, and the number of exchangeable filter cassettes is arbitrary. Further, the rotary filter may be replaceable without being built in the filter cassette.

In each filter cassette, a motor and a rotary encoder may be provided together with the rotary filter.

The present invention can be applied not only to an endoscope that receives reflected light from an object to be observed, but also to an endoscope that receives light transmitted through the object to be observed and observes the received light. .

Further, the present invention is not limited to an electronic endoscope having a solid-state image pickup device at the distal end of the insertion section, but may be applied to an eyepiece of an endoscope such as a fiberscope capable of observing the naked eye. The present invention can also be applied to an endoscope apparatus used by connecting a television camera by replacing the unit.

[0055]

As described above, according to the present invention, by providing a balancer in a part of a rotary filter, a smooth rise of rotation and stable rotation can be obtained, and illumination light of each wavelength region can be obtained. Can be supplied stably.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an endoscope device to which a light source device is connected.

FIG. 2 is a side view showing the entire endoscope apparatus.

FIG. 3 is a cross-sectional view of a filter cassette showing a basic configuration of a rotary filter.

FIG. 4 is a sectional view taken along line AA ′ of FIG. 3;

FIG. 5 is a perspective view of a filter cassette changer.

FIG. 6 is a plan view of a filter cassette changer.

FIG. 7 is a perspective view showing the rear side of the filter cassette changer.

FIG. 8 is a sectional view taken along the line BB ′ of FIG. 6;

FIG. 9 is an explanatory diagram showing transmission characteristics of each filter of a rotation filter for normal observation.

FIG. 10 is an explanatory diagram showing transmission characteristics of each filter of a special image rotation filter.

FIG. 11 is an explanatory diagram showing transmission characteristics of each filter of a rotation filter for a special image.

FIG. 12 is an explanatory diagram showing a change in blood absorbance due to a change in oxygen saturation of hemoglobin.

FIG. 13 is an explanatory diagram showing a change in blood absorbance due to a change in oxygen saturation of hemoglobin.

FIG. 14 is a cross-sectional view of a filter cassette showing another example of a rotary filter for normal observation.

FIG. 15 is a cross-sectional view of a filter cassette showing a rotary filter according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope 6 ... Video processor 20 ... Light source device 21 ... Lamp 50 ... Filter cassette 51 ... Rotating filter 51a, 51b, 51c ... Filter 70 ... Filter cassette changer 90 ... Frame body 91 ... Balancer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G02B 23/24 G02B 23/24 B (72) Inventor Akihiko Miyazaki 2-43-2 Hatagaya, Shibuya-ku, Tokyo O-Limpus Optical Industrial Co., Ltd. Within the company (72) Inventor Takeaki Nakamura 2-43-2 Hatagaya, Shibuya-ku, Tokyo O-Rinpas Optical Industry Co., Ltd. (72) Inventor Yoshinao Ohaki 2-43-2 Hatagaya, Shibuya-ku, Tokyo O-Rinpas Optical Co., Ltd. (72) Inventor Hiromasa Suzuki 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (56) References JP-A-62-2927 (JP, A) (58) Fields investigated (Int.Cl. ⁶ , DB name) G02B 23/24-23/26 A61B 1/04 G02B 7/00 F21V 9/10

Claims (1)

(57) [Claims] 1. A rotary filter provided in a light source device for an endoscope and emitting light in a different wavelength region by transmitting white light emitted from a light source, wherein a balancer is provided in a part of the rotary filter. A rotary filter of a light source device for an endoscope.