JP2002159445A - Electronic endoscope and scope of electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a structure of a front end of a scope, and to adjust brightness of an image of a subject displayed on a screen by exposing a part to light depending on a configuration of the part under the observation. SOLUTION: A light guide 50 is placed inside a video scope 40. The light guide 50 is formed into a Y shape with two light fiber bundles 50A, 50B. An inlet end 52 of the light guide 50 is divided into inlet ends 52A, 52B for the respective light fiber bundles 50A, 50B, and an output end 51 of the light guide 50 is formed by placing the inlet ends 51A, 51B for the respective light fiber bundles 50A, 50B concentrically. The first and the second LED lamps 15A, 15B are placed to correspond the inlet ends 52A, 52B. Light emitted from the first and the second LED lamps 15A, 15B is adjusted separately by the first and the second lamp drivers 14A, 14B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus provided with a videoscope having an image sensor, and a processor for processing an image signal read from the image sensor and outputting a video signal to a monitor. And light emission control of a light source that emits light transmitted to the tip of the scope.

[0002]

2. Description of the Related Art Usually, a video guide having an image pickup device is provided with a light guide (optical fiber bundle) for transmitting light emitted from a light source in a processor to a distal end of a scope on an observation site side. Emitted from the light source,
Light emitted from the exit end of the light guide, which is the end face on the tip end side, passes through the light guide and irradiates the observation site via the light distribution lens. The light distribution lens is a diffusion lens that diffuses light, and the light emitted from the light emitting end of the light guide reaches the observation site while being diffused. By illuminating the entire observation area with the light distribution lens and projecting the image on the monitor screen, the automatic dimming function is activated.
Appropriate brightness is obtained in both the center and the periphery of the screen.

[0003]

However, when the object to be observed is a lumen such as the large intestine, the peripheral portion of the screen is too bright and the brightness at the center decreases, and the object to be observed is a flat portion such as the stomach wall. In some cases, the vicinity of the center may be extremely bright and cause halation. As described above, if the brightness of the subject image projected on the screen is deviated due to the difference in the shape of the observation target, it becomes difficult to observe and treat the affected part.

In order to solve such a problem, for example, in order to separately irradiate a peripheral portion and a central portion of an observation region,
There is known a method in which a light guide formed by combining optical fiber bundles having different numerical apertures is formed in a Y-shape, and light is emitted from two branched outgoing ends toward a peripheral portion and a central portion (Japanese Patent Application Laid-Open No. 9-1997). No. 66020). Regarding the light quantity adjustment, a movable shielding plate is provided between the light-receiving end and the light source in order to separately adjust the intensity of light emitted from the two light-emitting ends. However, in such a method, it is necessary to provide two light distribution lenses, and the size of the tip becomes large. Further, in the light amount adjustment using the shielding plate, the total light amount reaching the observation site changes, and a power loss occurs due to a decrease in the light use efficiency of the lamp corresponding to the shielded light.

Accordingly, in the present invention, it is possible to simplify the structure of the distal end portion of the scope, irradiate light to the site according to the shape of the observation site, and to appropriately adjust the brightness of the subject image displayed on the screen. It is an object of the present invention to obtain an electronic endoscope device that can be used.

[0006]

According to an electronic endoscope apparatus of the present invention, a scope having an image pickup device on which a subject image is formed, a light guide for transmitting light to a distal end of the image pickup device, and an image display device. A processor to which a display device for displaying is connected and to which a scope is detachably connected, the processor comprising: a processor for converting an image signal corresponding to a subject image read from the image sensor into a video signal and outputting the video signal to the display device. . The light guide is constituted by at least two optical fiber bundles, and the incident end of the optical light guide on the processor side is branched for each incident end of the at least two optical fiber bundles, while at least two optical fiber bundles are bundled. Thus, the light guide on the distal end side of the scope is formed as one light emitting end. The processor is a lamp for a light source, the lamp being arranged to correspond to each of the entrance ends of the at least two optical fiber bundles, and emitting light to the entrance ends of the at least two optical fiber bundles, respectively, and the output of the lamp. And a light amount control means for adjusting the light amount of light incident on the incident end of the light guide for each of at least two optical fiber bundles.

The light guide is divided into at least two incident ends and the output of the lamp is controlled in accordance with each of the incident ends, so that the light exits from the exit end of the light guide as compared with the emission of light by a single light source. Brightness distribution of light (intensity distribution)
Can be unevenly distributed. Therefore, by determining the amount of light incident on each of at least two optical fiber bundles in accordance with the shape of the observation site, the subject image projected on the screen is maintained at an appropriate brightness over the entire screen.
In addition, since the light guide has one emission end, only one light distribution lens is required, and the configuration of the distal end of the scope is simplified. In order to reduce the size of the light source and efficiently emit light to the incident end of the light guide, it is desirable that the lamp is formed of a light emitting diode.

In order to separately adjust the intensity of light applied to the central portion and the peripheral portion thereof along the emission direction of the observation site, the emission end of the light guide is formed so that the emission ends of at least two optical fiber bundles are concentric. It is desirable to be formed by being arranged in.

[0009] Preferably, the light guide is constituted by first and second optical fiber bundles. in this case,
A first exit end, which is an exit end of the first optical fiber bundle, and a second exit end;
As for the exit end of the light guide formed by the second exit end that is the exit end of the optical fiber bundle, the first exit end is the center of the exit end of the light guide, and the second exit end surrounds the first exit end. It is preferable that the first and second emission ends are formed concentrically. Accordingly, the first and second lamps are arranged to correspond to the first and second incident ends of the first and second optical fiber bundles, respectively. Preferably, the light amount control means separately adjusts the outputs of the first and second light emitting diode lamps.

In order to make the brightness of the subject image projected on the screen uniform throughout, the light emission amount control means reflects the light to the subject after emitting from the emission end of the light guide, and reflects the image to the imaging surface of the imaging device (light receiving surface). It is desirable to adjust the outputs of the first and second light emitting diode lamps so that the illuminance distribution of the light reaching the surface (2) is substantially uniform. However,
The illuminance distribution of light reaching the imaging surface of the imaging device means a voltage level (distribution of the accumulated charge amount) distribution of an image signal read from the imaging device. Normally, the scope has a light distribution lens and an objective lens which are respectively arranged on the light emitting end of the light guide and the tip end side of the image sensor, and have respective illuminance distribution characteristics. However, the illuminance distribution characteristic of the light of the light distribution lens indicates the characteristic of the illuminance distribution on the irradiation surface of the subject when light of uniform luminance distribution enters the light distribution lens 43, and the illuminance distribution of the light of the objective lens The characteristics represent the characteristics of the illuminance distribution of light reaching the imaging surface of the imaging device when light having a uniform luminance distribution enters the objective lens. In this case, in consideration of the illuminance distribution characteristics of the light distribution lens and the objective lens, the light amount control unit reflects the light emitted from the light-emitting end of the light guide and irradiating the subject through the light distribution lens, thereby setting the objective lens. It is desirable to adjust the outputs of the first and second light emitting diode lamps so that the illuminance distribution of light on the imaging surface of the image sensor when reaching the image sensor via the light source becomes substantially uniform.

On the other hand, the output ends of at least two optical fiber bundles are each formed in a fan shape so as to divide the area of the output end of the light guide as a shape different from the concentric arrangement at the output end of the light guide. Is desirable. This makes it possible to separately adjust the light intensity of each of the regions of the subject in the direction toward the emission end of each optical fiber bundle.

[0012] Preferably, the light guide is constituted by first and second optical fiber bundles. in this case,
A first exit end, which is an exit end of the first optical fiber bundle, and a second exit end;
An emission end of the light guide formed by the second emission end, which is the emission end of the optical fiber bundle, is formed by the first emission end and the second emission end in a semicircular shape, and the lamp is configured to receive the first optical fiber bundle. First and second light-emitting diode lamps disposed so as to correspond to a first incident end, which is an end, and a second incident end, which is an incident end of the second optical fiber bundle, respectively; It is desirable to adjust the output of the first and second light emitting diode lamps separately.

When the object image to be projected is divided into two equal parts along the directions of the emission ends of the first and second optical fiber bundles, one area does not have a difference in brightness from the other area. Therefore, the light amount control unit determines that the brightness of the subject image displayed on the display device is symmetric with respect to the first area corresponding to the first emission end and the second area corresponding to the second emission end of the imaging surface of the imaging device. It is desirable to adjust the outputs of the first and second light emitting diode lamps so that Even when the shape of the subject is asymmetric (a shape in which one is depressed), the subject image is displayed with appropriate brightness.

In order to always bring the brightness of the subject image into an appropriate state, the processor determines the brightness value of the first area and the brightness value of the second area based on the image signal read from the image sensor at predetermined time intervals. It is desirable to have a brightness value calculation means for calculating each of the following. When the difference between the brightness value of the first area and the brightness value of the second area is equal to or more than a predetermined value,
It is desirable to adjust the outputs of the first and second light emitting diode lamps such that the luminance value of the first region and the luminance value of the second region are substantially equal.

A scope of an electronic endoscope apparatus according to the present invention has an image pickup device on which a subject image is formed, and a light guide for transmitting light in the direction of a tip end of the image pickup device, and displays a video image. There is a scope of an electronic endoscope apparatus to which a device is connected and which is detachably connected to a processor which converts an image signal corresponding to a subject image read from an image sensor into a video signal and outputs the video signal to a display device. The light guide is composed of at least two optical fiber bundles, and the incident end of the optical light guide on the processor side is branched for each incident end of the at least two optical fiber bundles, while the at least two optical fiber bundles are bundled. Accordingly, the emission end of the light guide on the distal end side of the scope is formed as one emission end.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic endoscope apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing an electronic endoscope apparatus according to the first embodiment.

The video scope 40 is detachably connectable to the processor 10, and a monitor 30 for displaying an observation image is connected to the processor 10. While an examination, an operation, or the like is performed, the insertion section 49 of the video scope 40 is inserted into the body. At the tip of the connector section 46 of the video scope 40, light source insertion ports 47A and 47B and an electric connector 46B are attached.

The video scope 40 includes a processor 1
A light guide (not shown) for transmitting a lamp (not shown) for the light source (not shown here) in the videoscope 40 to the distal end portion 48 of the video scope 40 is provided, and the light source insertion openings 47A and 47B are provided. The ends 47AT and 47BT serve as the light guide entrance ends, respectively. An insertion port 22B and an electric socket 22A are provided in the connection portion 21 of the processor 10 where the video scope 40 is mounted, and the light source insertion ports 47A and 47B are inserted into the insertion port 22B of the processor 10 and an electric connector is provided. 46B is mounted on the electric socket 22A. A power switch PW and a panel switch 18 are provided on the front of the processor, and the panel switch 18 is operated by an operator to set a reference value at the time of automatic light control.

FIG. 2 is a block diagram of the electronic endoscope apparatus, and FIG. 3 is a front view schematically showing an emission end of the light guide.

A light guide 50 provided in the video scope 40 for transmitting light to the distal end portion 48 of the video scope 40 includes two optical fiber bundles 50A (first optical fiber bundle) and an optical fiber bundle (second optical fiber bundle). The optical fiber bundle 50B is formed in a Y-shape. The light emitting end 52 of the light guide 50 is branched into two, and the incident ends of the optical fiber bundles 50A and 50B become the light guide incident ends 52A and 52B, respectively.

The light guide 50 is provided in the processor 10.
A first LED lamp (first light-emitting diode lamp) 15A and a second LED lamp 15 (second light-emitting diode lamp) B that constitute the lamp 15 are provided so as to correspond to the incident ends 52A and 52B. The first and second LED lamps 15A and 15B are constituted by a plurality of light emitting diodes, and each of the first and second LED lamps
A, It is turned on by the second lamp driver 14B. Light emitted from the first LED lamp 15A is incident on one incident end 52A of the light guide 50, and light emitted from the second LED lamp 15B is incident on the other incident end 52B. Almost all of the parallel light emitted from the first LED lamp 15A and the second LED lamp is incident on the incident end 52A and the incident end 52B of the light guide 50 without leakage.

Two optical fiber bundles 50A, 50B
Are bundled as a single fiber cable on the side of the distal end portion 48 in the video scope 40, and the output end 51 of the light guide 50 is connected to the optical fiber bundle 50A.
Exit end (first emission end) 51A and optical fiber bundle 5
The emission end (second emission end) 51B of OB forms one emission surface. All the light incident on the incident end 52A of the optical fiber bundle 50A passes through the optical fiber bundle 50A and exits from the exit end 51A. Similarly,
All the light incident on the optical fiber bundle incident end 52B passes through the optical fiber bundle 50A and exits from the exit end 51A. The optical fiber bundles 50A, 50B
Are formed by a large number of microfibers, each of which is composed of a core and a clad.

As shown in FIG. 3, the output end 51 of the light guide 50 is formed so that the output end 51A and the output end 51B are arranged concentrically, and the center of the output end 51A is an optical fiber bundle 50A. The emission end 51A of the optical fiber bundle 50B is arranged around the emission end 51A. At the distal end portion 48 of the video scope 40, a light distribution lens 43 for diffusing light is provided with a light guide 50.
Is disposed on the front surface (front end side) of the emission end 51. 1st LE
Light emitted from the D lamp 15A and emitted from the emission end 51A irradiates the observation site S along the center direction of the distal end portion 48 through the light distribution lens 43. The portion irradiated by the light from the emission end 51A is near the center of the screen of the subject image displayed on the monitor 30. On the other hand, the light emitted from the first LED lamp 15B and emitted from the emission end 51B illuminates the periphery of the observation site S irradiated by the light from the first LED lamp 15A. This emission end 51
The portion irradiated by the light from B is near the periphery of the subject image displayed on the monitor 30.

The light reflected at the observation site S is transmitted to the objective lens 4
1 and reaches a CCD 42 which is one of the image pickup devices. As a result, the image (subject image) of the observation site S becomes CC
D42 is formed on the light receiving surface. In the present embodiment, a simultaneous single-plate system is applied as a color imaging system, and a complementary color filter including color elements of cyan (Cy), magenta (Mg), yellow (Ye), and green (G) is provided on the light receiving surface. Is placed on top. In the CCD 42, an image signal corresponding to the subject image is generated by photoelectric conversion. CCD4
2 is driven by a CCD driver 59, and image signals corresponding to the colors that have passed through the complementary color filters are sequentially read out collectively for each frame and sent to the initial circuit 44. The image signal subjected to the amplification processing or the like in the initial circuit 44 is output to the signal processing circuit 11 in the processor 10. Here, the NTSC system is applied as a color television standard, and an image signal for one frame is 1/3.
The data is read from the CCD 42 at intervals of 0 seconds.

In the signal processing circuit 11, noise removal, A /
Processing such as D conversion is performed on the transmitted image signal. Further, the signal processing circuit 11 calculates a luminance value based on the image signal for one frame, and obtains a luminance signal of the image of the observation site S displayed on the monitor 30 as described later. The digitized image signal is sent to a video processing circuit 12, and the luminance signal is sent to a system control circuit 13.

In the video processing circuit 12, analog conversion is performed on the digitized image signal, and the analogized image signal is converted into a video signal such as an NTSC composite signal. By outputting the video signal to the monitor 30, an image of the observation site S is displayed on the screen of the monitor 30.

A CPU (not shown) and an RO which is a memory
The system control circuit 13 including the M and the RAM controls the processor 10 and the video scope 40. In the system control circuit 13, a control signal is output to the first lamp driver 14A and the second lamp driver 14B, and based on the control signal, the first and second lamp drivers 14A and 14B output the first and second LED lamps 15A, A current for lighting each of the lamps 15B flows. Based on the control signal, the first and second LED lamps 1
The intensity (light amount) of light emitted from 5A and 15B is separately adjusted. In the timing generator 17, a CCD
A clock pulse is output to each circuit such as the driver 59, the initial circuit 44, and the signal processing circuit 11, and the processing timing of the image signal in each circuit is adjusted according to the clock pulse.

The EEPROM 47 has a video scope 4
0 (electrical characteristics such as the type or name of the video scope 40 and the number of pixels of the CCD 42) are stored in advance, and when the video scope 40 is connected to the processor 10, the data is automatically stored in the EEPROM.
Read from the OM 47, the system control circuit 1
Sent to 3. When the reference brightness value of the automatic light control is set by the panel switch 18, a signal corresponding to the set value is sent to the system control circuit 13. Further, in the system control circuit 13, the transmitted data relating to the type of the video scope 40 is compared with a look-up table indicating the illuminance distribution characteristics of the light distribution lens and the objective lens for each scope type, and the connected video scope Data on the illuminance distribution characteristics of the 40 light distribution lenses 43 and the objective lens 41 are extracted.

FIG. 4 is a diagram showing the cross-sectional shape of the light-emitting end 51 of the light guide 50, the light distribution lens 43, and the observation site S. FIG. 5 is a diagram showing the first and second LED lamps 15A and 15A.
The light emitted from 5B irradiates and reflects on the observation site S,
FIG. 6 is a diagram showing an illuminance distribution, a luminance distribution, and the like of light until the reflected light reaches the CCD 42. The relationship between the luminance distribution of light emitted from the first and second LED lamps 15A and 15B and the illuminance distribution of light reaching the CCD 42 will be described with reference to FIGS. Here, the observation site S has a planar shape, and the first LED lamp 15A
And the intensity of light emitted from the second LED lamp 15B is equal. Also, in FIG. 4, the light path for irradiating the observation site S by the light distribution lens 43 and the observation site S
The optical path of the reflected light from the object is drawn for convenience, and the objective lens 41 and the CCD 42 are indicated by broken lines on the reflected optical path.

First and second LED lamps 15A, 15
As shown in FIG. 5, the intensity distribution (luminance distribution) of the light emitted from B, that is, the luminance distribution of the light incident on the incident ends 52A and 52B of the light guide 50, is shown in FIG.
The distribution is uniform along directions r1 and r2 perpendicular to the central axes of A and 52B. However, the incident end 5 of the light guide 50
The brightness of the light incident on each of the incident ends 2A and 52B is the same throughout the entire incident end, and if the direction is perpendicular to the central axis of the incident ends 52A and 52B, the distribution other than the directions r1 and r2 is the same uniform distribution. Hereinafter, the first and second LED lamps 1
The intensity distributions of light emitted from 5A and 15B are represented by luminance distributions D1 and D2, respectively, and the magnitude of luminance is represented by I.

First and second LED lamps 15A, 15
The light emitted from B is a parallel light,
Is emitted without attenuating while being totally reflected, the luminance distribution L0 of the light emitted from the emission end 51 is in the direction r.
And a uniform distribution along. However, the direction r passing through the central axis of the exit end 51 of the light guide 50 is
R1 and r2 passing through the central axes of the incident ends 52A and 52B of
Corresponding to As described above, at the emission end 51 of the light guide 50, the emission end 51A corresponding to the first LED lamp 15A and the emission end 51 corresponding to the second LED lamp 15B.
Since B and B are arranged concentrically, the luminance distribution D'1 indicated by the broken line corresponds to the luminance distribution D1, and the luminance distribution D '
The luminance distribution D'2 on both sides of 1 corresponds to the luminance distribution D2.

The illuminance distribution characteristic M0 of the light by the light distribution lens 43 shown in FIG. 5 is the irradiation surface of the observation site S when the light having the uniform luminance distribution represented by the broken line M0 'enters the light distribution lens 43. The illuminance distribution above is shown. The illuminance distribution on the irradiation surface of the observation site S is an illuminance distribution represented along a line along the direction r with the center at the intersection SC between the central axis U at the emission end 51 and the observation site S. The light distribution lens 43 is a lens having rotational symmetry with respect to the central axis U, and the illuminance distribution characteristics other than the direction r have the same curve distribution. Here, the magnitude of the illuminance is represented by I ′, and the distance from the intersection SC on the irradiation surface of the observation site S is represented by θ. Note that θ is a reference point BR between the exit surface 43B of the light distribution lens 43 and the center axis U of the exit end 51, and a reference point BR and a position (for example, a position SG) on the irradiation surface of the observation region S to be obtained. Represents a corner.

As can be seen from the illuminance distribution characteristic M 0, the luminance of the light passing through a position distant from the center of the light distribution lens 43 decreases due to the influence of diffusion by the light distribution lens 43.
Here, since the luminance distribution L0 of the light emitted from the emission end 51 is uniform, the illuminance distribution Z0 when the light passing through the light distribution lens 43 irradiates the observation site S has a large illuminance near the center SC. , A distribution curve in which the illuminance in the peripheral portion is small.

The illuminance distribution characteristic J0 of the light of the objective lens 41 shown in FIG. 5 is the illuminance distribution characteristic J0 'of the illuminance distribution on the light receiving surface of the CCD 42 when the light of uniform luminance distribution indicated by the broken line J0' is incident on the objective lens 41. Indicates characteristics. The illuminance distribution here is
The distribution of the voltage level of the image signal read from the CCD 42 (that is, the accumulated charge amount in a predetermined time) is shown, and its magnitude is represented by I ″.
2 is a distribution curve along a direction X passing through the center of the light receiving surface of No. 2 and along a direction r. However, the objective lens 41, the CCD 42
Of the objective lens 41, such that the axis U ′ passing through the center of the light guide 50 is parallel to the central axis U at the emission end 51 of the light guide 50.
It is assumed that the CCD 42 is arranged. Objective lens 4
The illuminance distribution characteristic J0 of No. 1 has the same tendency as the illuminance distribution characteristic M0 of the light distribution lens 43. When the illuminance distribution of the light reflected on the plane of the observation site S is uniform, the light is CC.
When the light reaches D42, the illuminance of the peripheral portion away from the center X0 of the light receiving surface decreases. The light represented by the illuminance distribution Z0 is C
Since the light reaches the light receiving surface of the CD 42, the illuminance distribution P0 of the light on the light receiving surface of the CCD 42 becomes as shown in FIG.
The distribution curve has extremely low illuminance near both ends of the light receiving surface distant from the center X of the light receiving surface.

As described above, the first and second LED lamps 1
If the luminance distributions of the light radiated from 5A and 15B are equal, the illuminance distribution of the light reaching the light receiving surface of the CCD 42 is not uniform due to the illuminance distribution characteristics of the light distribution lens 43 and the objective lens 41. As a result, on the screen of the monitor 30, an image having different brightness at the periphery of the screen and near the center of the screen is displayed. Further, when the shape of the observation site S is spherical or luminal (tubular), an image having a desired brightness distribution can be obtained simply by emitting light having the same brightness distribution from the LED lamps 15A and 15B. I can't get it.

In the present embodiment, the LED lamp 15A according to the shape of the observation object is set so that the illuminance distribution of light on the light receiving surface of the CCD 42, that is, the integrated value of the voltage level distribution of the image signal read from the CCD 42 becomes uniform. , 15
The intensity of the light emitted from B is adjusted separately and appropriately.

Referring to FIG. 6 to FIG.
The intensity of light emitted from A and 15B will be described. In the present embodiment, a planar shape, a spherical shape, and a lumen shape are considered as the shape of the observation site S, and the light emission intensity, that is, the output of the LED lamps 15A and 15B is adjusted to correspond to each shape.

Normally, video scopes are properly used depending on the object to be observed. The optical systems mounted on these video scopes are mainly optical systems suitable for observing lumen-shaped parts such as the large intestine. In addition, there is an optical system suitable for observing a planar or spherical site such as a stomach. That is, it is desired that the illuminance distribution characteristics of the light distribution lens and the objective lens also correspond to the shape of the observation site. In the following, a scope for observing the upper gastrointestinal tract such as the stomach is a video scope 40 of type A, a scope for observing parts other than the upper and lower gastrointestinal tracts is a video scope 40 of type B, and a lower scope such as the large intestine. The scope for observing the tube is referred to as a video scope 40 of type C, and the LED lamp 15 that is driven and controlled in accordance with each shape.
A description will be given of the illuminance distribution on the light receiving surface of the CCD due to light emitted from A and 15B.

FIG. 6 is a view showing a video scope 40 of type A and an observation site S having a spherical shape such as the inside of the stomach. FIG. 7 shows first and second LEDs corresponding to the spherical shape.
FIG. 5 is a diagram showing a luminance distribution of light emitted from lamps 15A and 15B, an illuminance distribution on a spherical surface, and an illuminance distribution on a light receiving surface of CCD 42.

As shown in FIG. 6, when the observation site S is spherical, the observation site along the center axis U from the reference point BR of the exit surface 43AB of the light distribution lens 43A in the type A video scope 40 The distance from the exit surface 43B to the peripheral portion of the observation site S away from the center SC is substantially equal to the distance to the center SC of S. Due to such a spherical shape, the light distribution lens 4 provided in the type A video scope 40 is provided.
Illuminance distribution characteristics of 3A and the objective lens 41A are determined by illuminance distributions M1 and J1 as shown in FIG.

First and second LED lamps 15A, 15
As can be seen from the luminance distributions E1 and E2 of B (see FIG. 7), the luminance IE1 of the first LED lamp 15A is equal to the second L
The brightness is smaller than the brightness IE2 of the ED lamp 15B. Therefore, the luminance distribution L1 at the light emitting end 51 of the light guide 50
Has a luminance distribution in which the luminance at the center of the emission surface 51 is small and the luminance near the periphery of the emission surface 51 is large. When the light emitted from the emission end 51 passes through the light distribution lens 43A having the illuminance distribution characteristic M1, the illuminance distribution Z1 of the spherical observation site S becomes a curve distribution as shown in FIG. Then, the light is reflected on the spherical surface of the observation site S, passes through the objective lens 41A, and is reflected by the CCD.
The illuminance distribution P1 of the light that has reached the light receiving surface 42 is a substantially uniform distribution.

When the type A videoscope 40 corresponding to the spherical observation site S is used, the first L
The first and second LED lamps 15A and 15B are controlled such that the luminance of light emitted from the second LED lamp 15B is higher than that of the ED lamp 15A. In other words, the magnitudes IE1 and IE2 of the brightness of the light emitted from the first and second LED lamps 15A and 15B are
The brightness is determined so that the brightness distribution on the light receiving surface of No. 2 is substantially uniform.

FIG. 8 is a view showing an observation site S having a planar shape among observation sites other than the upper digestive tract and the lower digestive tract, and FIG. 9 is a view showing the first and second LEDs with respect to the planar shape.
FIG. 4 is a diagram showing a luminance distribution of light emitted from the lamps 15A and 15B, an illuminance distribution on a plane, and an illuminance distribution on a light receiving surface of the CCD 42.

As shown in FIG. 8, when the shape of the observation site S is planar along a direction substantially perpendicular to the direction of the irradiation optical axis (center axis U), the arrangement provided on the type B videoscope 40 is required. Reference point BR of exit surface 43BB of optical lens 43B
The distance from the reference point BR to a position (here, represented by a position SR) away from the center SC of the observation site S is longer than the distance from the reference point BR to the center SC of the observation site S along the central axis U. The light distribution lens 43B and the objective lens 41B provided in the type B video scope 40 have illuminance distribution characteristics M2 and J2 as shown in FIG. 9 in consideration of the planar shape.

First and second LED lamps 15A, 15
As can be seen from the brightness distributions F1 and F2 of the light emitted from B (see FIG. 9), the brightness IF1 of the light emitted from the first LED lamp 15A is higher than the brightness IF2 of the light emitted from the second LED lamp 15B. small. This difference in brightness Δ
D is larger than the luminance difference when the observation site S is spherical (see FIGS. 7 and 9). At this time, the light guide 50
The first and second lamps 15A and 15B are controlled such that the luminance distribution L2 at the emission end 51 is extremely small near the center of the emission end 51 and large near the periphery. When light based on such a luminance distribution L2 irradiates the observation site S through the light distribution lens 43B, the illuminance distribution Z2 on the plane is obtained.
Has a curve distribution as shown in FIG. And CCD
The illuminance distribution P2 of light on the light receiving surface 42 is substantially substantially uniform.

FIG. 10 is a view showing an observation site S having a lumen shape such as the inside of the large intestine. FIG. 11 is a diagram showing a luminance distribution of light emitted from the LED lamps 15A and 15B with respect to the lumen shape, FIG. 4 is a diagram showing an illuminance distribution of the light receiving surface of FIG.

As shown in FIG. 10, when the observation site S has a tubular shape, the light emitted from the emission end 51 is reflected on the inner wall of the observation site S while traveling along the central axis U of the emission end 51. The light that forms is hardly reflected. Such an observation site S
The light distribution lens 43C and the objective lens 41C provided in the type C videoscope 40 according to the shape of
It has illuminance distribution characteristics M3 and J3 as shown in FIG.

First and second LED lamps 15A, 15
As can be seen from the luminance distributions G1 and G2 of the light radiated from B (see FIG. 11), the luminance IG1 of the light radiated from the first LED lamp 15B is higher than the luminance IG2 of the light radiated from the first LED lamp 15A. Adjusted to be larger. Therefore, the luminance distribution L3 of the light at the emission end 51 of the light guide 50 has a large luminance near the central axis U and a small luminance near the periphery. The illuminance distribution Z3 when the light of the luminance distribution L3 is applied to the lumen-shaped observation site S via the light distribution lens 43C has a large illuminance near the center position SC along the central axis U, and the illuminance is large. The illuminance is low at the periphery near the inner wall. The illuminance distribution P3 of the light on the light receiving surface of the CCD 42 is substantially substantially uniform.

FIG. 12 is a main routine showing the operation of the entire processor. When the power of the processor 10 is turned on, the execution of the main routine is started.

In step 101, the aperture, the LED lamps 15A, 15B and the like are set to initial values. Step 1
In 02, scope-related processing described later is executed.
In step 103, other processing such as date display processing is executed. Until the power turns off
Steps 102 and 103 are repeated.

FIG. 13 shows the first diagram according to the scope connection.
And step 10 showing a light emission adjusting operation for adjusting the intensity of light emitted from the second LED lamps 15A and 15B.
This is the second subroutine. Here, the video scopes 40 of the types A, B, and C described above are connected to the processor 10 as appropriate.

In step 201, the video scope 40
It is determined whether or not is removed. That is, the video scope 40 which has been connected to change the observation region and replace it with a new type of video scope 40 is used.
It is determined whether or not has been removed. Video scope 4
If it is determined that 0 has been removed, step 202
Proceed to. On the other hand, if it is determined that the video scope 40 has not been removed and remains connected, this routine ends.

In step 202, the video scope 40
Is newly connected. That is, it is determined whether or not the video scope 40 is newly connected from the state where the video scope 40 has been removed from the processor 10. If it is determined that the video scope 40 is newly connected, the process proceeds to step 203. On the other hand, if it is determined that the videoscope 40 has not been connected to the processor 10 after being removed, step 102 is repeatedly executed until the videoscope 40 is connected.

In step 203, data including scope type information is read from the EEPROM 47 in the connected video scope 40 and sent to the system control circuit 13. Then, in step 204, it is determined whether or not the connected video scope 40 is of type A.

If it is determined in step 204 that the connected video scope 40 is of type A, the process proceeds to step 208. In step 208, the initial settings of the luminance distribution of the light emitted from the first and second LED lamps 15A and 15B are respectively set to the luminance distributions E1 and E shown in FIG.
2, the first and second LED lamps 15A,
The output of 15B is adjusted. At this time, the first and second
First and second LEDs from LED lamps 14A, 14B
The current sent to the lamps 15A, 15B is equal to the brightness distribution E1,
The value is set to a value corresponding to E2. When step 208 is executed, this subroutine ends, and the process returns to step 102 in FIG. On the other hand, if it is determined in step 204 that the connected video scope 40 is not the type A, the process proceeds to step 205. In step 205, it is determined whether or not the connected video scope 40 is of type B.

If it is determined in step 206 that the connected video scope 40 is of type B, the process proceeds to step 206. In step 206, the first and second LED lamps 15 are set such that the initial settings of the luminance distribution of the light emitted from the first and second LED lamps 15A and 15B are the luminance distributions F1 and F2 (see FIG. 9), respectively.
The outputs of A and 15B are adjusted. When step 206 is executed, this subroutine ends, and the process returns to step 102 in FIG. On the other hand, if it is determined in step 206 that the connected video scope 40 is not the type B, the process proceeds to step 207.

In step 207, the first and second LEs
Initial settings of the luminance distribution of the light emitted from the D lamps 15A and 15B are luminance distributions G1 and G2 (see FIG. 11).
The first and second LED lamps 15A, 15A, 1
The output of 5B is adjusted. When step 207 is executed, this subroutine ends, and step 10 in FIG.
Return to 2.

Once the scope is connected, the first LED lamp 15A and the second LED lamp 15B executed when the scope is connected, unless the scope is removed.
Is maintained.

FIG. 14 is an interrupt routine for executing automatic light control. In the case of the NTSC system, this interrupt routine is executed by interrupting the main routine of FIG. 12 at intervals of 1/30 seconds.

In step 301, the LED lamp 15
It is determined whether A and 15B are lit. LED
When it is determined that the lamps 15A and 15B are turned on, the video scope 40 is connected to the processor 10, and
It is considered that an image signal has been read from the CCD 42, and the process proceeds to step 302. On the other hand, the first and second LEs
If it is determined that the D lamps 15A and 15B are not turned on, the video scope 40 is not connected to the processor 10, and it is determined that the image signal cannot be read from the CCD 42, and the interrupt routine ends.

In step 302, a representative luminance value is calculated from the luminance data for one frame obtained based on the image signal read from the CCD 42. The luminance data is data representing the luminance level of one frame of each pixel constituting the subject image displayed on the monitor 30.
However, the range of the luminance level is 0 to 255, and the luminance value of each pixel is classified into 256 levels. Then, a representative luminance value Ys is calculated based on the luminance data.
The representative luminance value here is an average value of the luminance levels of the respective pixels. When the representative luminance value Ys is calculated, step 303
Proceed to.

In step 303, it is determined whether or not the difference | Ys−Yr | between the representative luminance value Ys and the reference luminance value Yr is smaller than the allowable value C0 (here, the allowable value C0 = 5). Here, the reference luminance value Yr is 128. If the difference | Ys−Yr | between the representative luminance value Ys and the reference luminance value Yr is smaller than the allowable value C0, that is, if it is determined that the representative luminance value Ys and the reference luminance value Yr are substantially equal, the interrupt routine is executed. finish. On the other hand, if it is determined that the difference | Ys−Yr | between the representative luminance value Ys and the reference luminance value Yr is not smaller than the allowable value C, the process proceeds to step 304. Step 3
In 04, it is determined whether or not the representative luminance value Yr is larger than the reference luminance value Ys.

If it is determined in step 304 that the representative luminance value Yr is larger than the reference luminance value Ys, the process proceeds to step 305. In step 305, the representative luminance value Yr
And the second LED by the difference between the first and second LEDs
The first and second LED lamps 1 from the first and second lamp drivers 14A and 14B are so arranged that the brightness of the light emitted from the lamps 15A and 15B is reduced (to be darker).
The value of the current sent to 5A, 15B is adjusted. When step 305 is executed, the interrupt routine ends. On the other hand, when it is determined in step 304 that the representative luminance value Yr is not larger than the reference luminance value Ys, the process proceeds to step 306. In step 306, the representative luminance value Y
r and the reference luminance value Ys by the difference between the first and second LEs.
The value of the current sent from the first and second lamp drivers 14A, 14B to the first and second LED lamps 15A, 15B is set so that the brightness of the light emitted from the D lamps 15A, 15B is reduced (to be darker). Adjusted. When step 306 is executed, the interrupt routine ends.

As described above, according to the first embodiment, the light guide 50 includes two optical fiber bundles 50A and 50A.
B, the input end 52 of the light guide 50 is branched into two incident ends 52A and 52B,
Two optical fiber bundle light guides 50A, 50B
Are bundled to form the exit end 51 of the light guide 50 as one exit surface. And the first and second LEs
D lamps 15A and 15B are respectively incident ends 52A and 52A.
B and the optical fiber bundle 50
A, the illuminance (intensity) of the light emitted from the emission end 51A of the A and illuminating the vicinity of the center of the image of the observation site S observed on the screen, and the light emitted from the emission end 51B of the optical fiber bundle 50B are observed on the screen of the monitor 30. The illuminance (intensity) of light that illuminates the vicinity of the image of the observed region S to be observed is separately adjusted. As a result, a subject image having appropriate brightness is observed on the monitor 30 irrespective of the shape of the observation site S, that is, the type of the video scope 40.

The light guide 50 may be composed of three or more optical fiber bundles. In this case, the incident ends of the light guide 50 are provided by the number of fiber bundles, and the LED lamps are arranged so as to correspond to each incident end.

Next, a second embodiment will be described with reference to FIGS. In the second embodiment, unlike the first embodiment, the light emitting end of the light guide is divided into two semicircular portions, and the brightness of the subject image is detected at predetermined time intervals to adjust the brightness. Otherwise, the same components as those of the first embodiment are denoted by the same reference numerals.

FIG. 15 is a diagram showing a light guide according to the second embodiment, and FIG. 16 is a diagram showing an emission end of the light guide.

The light guide 150 is composed of two optical fiber bundles 150A and 150B, and has a Y-shape as in the first embodiment. Light emitted from the first and second LED lamps 15A and 15B is incident on the two incident ends 152A and 152B of the light guide 150, respectively. Light guide 150
Are bundled together on the exit end 151 side, and the exit ends 151A, 151A of the optical fiber bundles 150A, 150B.
One emission end 151 is formed by 51B.

As shown in FIG. 16, the output ends 151A and 151B of the optical fiber bundles 150A and 150B are each formed in a semicircular shape, and the circular output end 51 is divided into two along an axis AU passing through the center. I have. Thus, the emission end 1
The formation of the optical fiber bundle 15
It is possible to separately irradiate the directions on the observation site S to which the emission end 151A of the optical fiber 0A and the emission end 151B of the optical fiber bundle 150B face.

FIG. 17 is a diagram showing an example of the shape of the observation site S in the second embodiment, and FIG.
5 is a diagram showing a luminance distribution and an illuminance distribution of light emitted from the LED lamps 15A and 15B for the shape shown in FIG. Light guide 15
1, a video scope 40 having a light distribution lens 143, an objective lens 141, and the like is represented as a type D scope here. The type D video scope 40 is a scope for observing the same upper digestive tract as the type A.

In the upper gastrointestinal tract observation, the observation site S is shown in FIG.
7, that is, the output end 15
1 has an asymmetric shape with respect to the intersection SC between the central axis U and the observation site S, and the site surface S1 of the observation site S corresponding to the optical fiber bundle 150A is closer to the observation site S corresponding to the optical fiber bundle 150B. Compared to the part plane S2 of
Light distribution lens 143 (tip portion 49 of video scope 40)
Long distance from.

As shown in FIG. 18, the light distribution lens 143 and the objective lens 14 in the video scope 40 of the type D
The illuminance distribution characteristics M4 and J4 of No. 1 are the same as the illuminance distribution characteristics M1 and J1 of the video scope 40 of type A. (See FIG. 7). When the shape of the observation site S is asymmetrical as shown in FIG. 17, the first and second LED lamps 15A and 15A
B has a luminance distribution H1 and a luminance distribution H2, respectively.
(See FIG. 18) The outputs of the first and second LED lamps 15A and 15B are adjusted. Brightness distribution H
1. As can be seen from H2, the second corresponding to the part plane S2
The luminance IH1 of the light radiated from the first LED lamp 15A corresponding to the part plane S1 far from the light distribution lens 143 is larger than the luminance IH2 of the light radiated from the LED lamp 15B. As a result, the brightness distribution L4 of the light emitted from the emission end 151 of the light guide 151 has a brightness distribution as shown in FIG.

Since the part plane S1 is located farther from the light distribution lens 143 than the part plane S2, the illuminance distribution Z4 in the asymmetric observation part S has a central axis U of the emission end 151 as shown in FIG. Is symmetrical with respect to. The illuminance distribution P2 of light on the light receiving surface of the CCD 42 is
The distribution becomes symmetric with respect to the center X0 of the light receiving surface.

FIG. 19 is an interrupt routine for executing automatic light control in the second embodiment. This interrupt routine is executed by interrupting the main routine at intervals of 1/30 seconds according to the NTSC system.

The execution of step 401 is the same as the execution of step 301 in FIG. That is, it is considered that the image signal has been read out by detecting the lighting of the lamp 15, and in that case, the process proceeds to step 402.

In step 401, the first area representative luminance value Ysa of the subject image area corresponding to the part plane S1 and the second area representative luminance value of the subject image area corresponding to the part plane S1 are displayed together with the representative luminance value Ys. Ysb is calculated. Here, the average luminance value of the left half area of the screen of the monitor 30 is calculated as the representative luminance value Ysa, and the average luminance value of the right half area of the screen is calculated as the representative luminance value Ysb.

The execution of step 403 is the same as the execution of step 303 in FIG. 14, and it is determined whether or not the difference | Ys−Yr | between the reference luminance value Yr and the representative luminance value Ys is equal to or smaller than the allowable value C0. Is done. If it is determined that the difference is equal to or smaller than the allowable value C0, the process proceeds to step 404.

In step 404, it is determined whether or not the difference | Ysa-Ysb | between the first and second region representative luminance values Ysa and Ysb is equal to or less than the region difference allowable value C1. First
And the difference between the second region representative luminance values Ysa and Ysb is equal to or less than the region difference allowable value C1, that is, it is determined that the brightness corresponding to the part plane S1 and the brightness corresponding to the part plane S2 are substantially the same. In this case, the interrupt routine ends. on the other hand. First and second region representative luminance values Ys
If it is determined that the difference between a and Ysb is not smaller than or equal to the region difference allowable value C1, that is, if it is determined that the difference between the brightness corresponding to the part plane S1 and the brightness corresponding to the part plane S2 is large, step 4 is performed.
Go to 05.

At step 405, it is determined whether or not the first region representative luminance value Ysa is smaller than the second region representative luminance value Ysb. If it is determined that the first area representative luminance value Ysa is smaller than the second area representative luminance value Ysb, the process proceeds to step 406, and the first and second area representative luminance values Ysa,
The output of the first LED lamp 15A is increased by the difference from Ysb. On the other hand, if it is determined that the first region representative luminance value Ysa is not smaller than the second region representative luminance value Ysb, that is, it is determined that the first region representative luminance value Ysa is larger than the second region representative luminance value Ysb, the process proceeds to step 407 and the difference between the first and second region representative luminance values Ysa and Ysb. The second L
The output of the ED lamp 15B is increased. Step 406
Alternatively, when step 407 is executed, this interrupt routine ends.

On the other hand, in step 403, the difference | Ys−Yr | between the reference luminance value Yr and the representative luminance value Ys is equal to the allowable value C.
If it is determined that the value is not less than 0, the process proceeds to step 408. The execution of steps 408 to 410 is the same as the execution of steps 304 to 306 in FIG.
r and the representative luminance value Ys, the first and second L
The output of the ED lamps 15A and 15B is increased or decreased. When step 409 or 410 is executed, the interrupt routine ends.

As described above, according to the second embodiment, the output end 151 of the light guide 150 is formed by the output end 151A of the optical fiber bundle 150A and the output end 151B of the optical fiber bundle 150B each formed in a semicircular shape. Then, the light emitted from the first and second LED lamps 15A and 15B is applied to the region of the observation site S facing the emission end 151A and the region of the observation site S facing the emission end 151B, respectively. Then, the first area representative luminance value Ysa
And the second area representative luminance value Ysb are calculated, and when the difference is large, the outputs of the first and second LED lamps 15A and 15B are adjusted so that the difference is eliminated. With such a configuration, it is possible to detect a subject image with appropriate brightness on the screen even in the observation site S having an asymmetric shape.

The type D video scope 40 is a scope corresponding to the upper digestive tract, but the light guide 150 may be provided for a scope corresponding to the lumen shape.

The light guide 150 may be constituted by three or more optical fiber bundles. In this case, the emission end of the light guide 150 is constituted by the emission end of each of the fan-shaped optical fiber bundles corresponding to the number of the optical fiber bundles. That is, one exit end surface is formed by the exit end obtained by dividing the exit end region of the light guide 150 into a fan shape. In this case, regarding the calculation of the representative luminance value, the area on the screen of the monitor 30 may be divided by the number of optical fiber bundles and the representative luminance value may be calculated for each area.

Note that instead of two sets of LEDs as the light source,
It may be constituted by two xenon or halogen lamps, and the intensity of light incident on the two light guide entrance ends may be individually controlled by two apertures or the like.

[0086]

As described above, according to the present invention, the configuration of the distal end portion of the scope is simplified, and light is applied to the site according to the shape of the observation site, and the brightness of the subject image displayed on the screen is improved. Can be appropriate.

[Brief description of the drawings]

FIG. 1 is a front view showing an electronic endoscope apparatus according to a first embodiment.

FIG. 2 is a block diagram of the electronic endoscope apparatus.

FIG. 3 is a front view schematically showing an emission end of the light guide.

FIG. 4 is a diagram showing an emission end of a light guide, a light distribution lens, and a cross-sectional shape of an observation site.

FIG. 5 shows illuminance distribution, luminance distribution, and C of light emitted from first and second LED lamps to reach a CCD.
FIG. 3 is a diagram illustrating an illuminance distribution on a light receiving surface of a CD.

FIG. 6 is a diagram showing an observation region having a spherical shape and a videoscope corresponding to the spherical shape.

FIG. 7 shows luminance distribution, illuminance distribution, and C of light with respect to a spherical shape.
FIG. 3 is a diagram illustrating an illuminance distribution on a light receiving surface of a CD.

FIG. 8 is a diagram showing an observation region having a planar shape and a videoscope corresponding to the planar shape.

FIG. 9 shows luminance distribution, illuminance distribution, and C of light with respect to a planar shape.
FIG. 3 is a diagram illustrating an illuminance distribution on a light receiving surface of a CD.

FIG. 10 is a diagram showing an observation site having a lumen shape and a videoscope corresponding to the lumen shape.

FIG. 11 shows luminance distribution, illuminance distribution,
FIG. 3 is a diagram illustrating an illuminance distribution on a light receiving surface of a CCD.

FIG. 12 is a main routine showing the operation of the entire processor.

FIG. 13 is a subroutine showing a light emission adjusting operation according to a scope connection.

FIG. 14 is an interrupt routine showing an automatic dimming operation.

FIG. 15 is a diagram illustrating a light guide according to a second embodiment.

FIG. 16 is a diagram showing an emission end of a light guide.

FIG. 17 is a diagram illustrating an example of a shape of an observation part according to the second embodiment.

FIG. 18 is a diagram showing a light luminance distribution, an illuminance distribution, and an illuminance distribution on a light receiving surface of a CCD with respect to a shape of an observation site in the second embodiment.

FIG. 19 is an interrupt routine illustrating an automatic dimming operation according to the second embodiment.

[Explanation of symbols]

Reference Signs List 10 processor 13 system control circuit 14A first lamp driver 14B second lamp driver 15 LED lamp (lamp) 15A first LED lamp (first light emitting diode lamp) 15B second LED lamp (second light emitting diode lamp) 30 monitor (display device) 40 Videoscope 41, 41A, 41B, 41C, 141 Objective Lens 42 CCD (Imaging Device) 43, 43A, 43B, 43C Light Distributing Lens 50, 150 Light Guide 50A, 150A Optical Fiber Bundle (First Optical Fiber Bundle) 50B, 150B Optical fiber bundle (second optical fiber bundle) 51 Outgoing end 51A, 151A First outgoing end 51B, 151B Second outgoing end 52 Incident end 52A Incident end (first incident end) 52B Incident end (second incident end)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) G02B 23/26 G02B 23/26 D H04N 7/18 H04N 7/18 M (72) Inventor Hiroshi Sano Tokyo 2-36-9 Maeno-cho, Itabashi-ku Asahi Gaku Kogyo Co., Ltd. (72) Inventor Kuniyoshi Kaneko 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Asahi Gaku Kogyo Co., Ltd. F-term (reference) 2H040 BA09 CA04 CA06 CA11 CA12 CA23 DA18 GA02 GA11 2H046 AA02 AA39 AB08 AD01 4C061 CC06 GG01 JJ06 LL01 NN01 QQ07 RR02 RR22 5C054 AA05 CA04 CC07 CH07 FC12 FF02 HA12

Claims (11)

[Claims] 1. A scope having an image sensor on which a subject image is formed, a light guide for transmitting light to a front end of the image sensor, and a display device for displaying an image are connected, and the scope is attached and detached. A processor that is freely connected and that converts an image signal corresponding to a subject image read from the image sensor into a video signal and outputs the video signal to the display device, wherein the light guide includes at least two optical fibers. The scope is configured such that the input end of the optical light guide on the processor side is branched for each of the input ends of the at least two optical fiber bundles, while the at least two optical fiber bundles are bundled. An emission end of the light guide on the distal end side is formed as one emission end, and the processor is A lamp for a light source, wherein the lamp is arranged to correspond to each of the incident ends of the at least two optical fiber bundles;
A lamp that emits light to an incident end of the at least two optical fiber bundles, and an output of the lamp is controlled to adjust an amount of light incident on an incident end of the light guide for each of the at least two optical fiber bundles. An electronic endoscope apparatus comprising: a light amount control unit. 2. The electronic endoscope apparatus according to claim 1, wherein the lamp comprises a light emitting diode. 3. The electronic endoscope according to claim 2, wherein an emission end of the light guide is formed by arranging the emission ends of the at least two optical fiber bundles concentrically. Mirror device. 4. The light guide is constituted by first and second optical fiber bundles, and is a first emission end as an emission end of the first optical fiber bundle and an emission end of the second optical fiber bundle. The light-emitting end of the light guide formed by a second light-emitting end is such that the first light-emitting end is the center of the light-emitting end of the light guide, and the second light-emitting end surrounds the first light-emitting end. 1st and 2nd
The light-emitting end is formed by being arranged concentrically, and the lamp has a first incident end which is an incident end of the first optical fiber bundle and a second incident end which is an incident end of the second optical fiber bundle. The first arranged to correspond to
4. The electronic endoscope according to claim 3, further comprising: a first light emitting diode lamp; and a second light emitting diode lamp, wherein the light amount control unit separately adjusts outputs of the first and second light emitting diode lamps. 5. Mirror device. 5. The light amount control unit according to claim 1, wherein the light emitted from an emission end of the light guide is reflected by a subject and reaches an imaging surface of the imaging device so that an illuminance distribution of the light becomes substantially uniform. The electronic endoscope apparatus according to claim 4, wherein the outputs of the first and second light emitting diode lamps are adjusted. 6. A light distribution lens having a predetermined light distribution illuminance distribution characteristic disposed in front of an emission end of the light guide, and a predetermined light distribution illuminance disposed in front of an imaging surface of the image sensor. An objective lens having a distribution characteristic, wherein the light amount control means reflects light emitted from an emission end of the light guide and irradiating a subject through the light distribution lens through the objective lens. The output of the first and second light-emitting diode lamps is adjusted so that the illuminance distribution of light on the imaging surface of the imaging device when reaching the imaging device has a substantially uniform distribution. Item 6. The electronic endoscope device according to item 5. 7. The electronic endoscope according to claim 2, wherein the emission ends of the at least two optical fiber bundles are formed in a fan shape so as to divide the area of the emission end of the light guide. apparatus. 8. The light guide is constituted by first and second optical fiber bundles, and is a first emission end as an emission end of the first optical fiber bundle and an emission end of the second optical fiber bundle. The light-emitting end of the light guide formed by the second light-emitting end has a semicircular shape.
The lamp is formed by an emission end and a second emission end, and the lamps correspond to a first incidence end which is an incidence end of the first optical fiber bundle and a second incidence end which is an incidence end of the second optical fiber bundle. Placed as the first
The electronic endoscope according to claim 7, further comprising: a second light-emitting diode lamp; and a light-amount control unit that separately adjusts outputs of the first and second light-emitting diode lamps. Mirror device. 9. The light amount control unit according to claim 1, wherein the brightness of the subject image displayed on the display device corresponds to a first area corresponding to a first emission end and a second area corresponding to a second emission end of an imaging surface of the imaging device. 9. The electronic endoscope device according to claim 8, wherein the outputs of the first and second light emitting diode lamps are adjusted so as to have symmetry with respect to the two regions. 10. A brightness value calculating means for calculating a brightness value of the first area and a brightness value of the second area based on an image signal read from the image sensor at predetermined time intervals. The light quantity control means is configured to determine the brightness value of the first area and the second area;
When the difference between the brightness value of the region and the brightness value of the second region is equal to or more than a predetermined value, the brightness value of the first region and the brightness value of the second region are substantially equal to each other. The electronic endoscope apparatus according to claim 9, wherein the output is adjusted. 11. An image pickup device on which a subject image is formed, and a light guide for transmitting light in the direction of a tip of the image pickup device. A scope of an electronic endoscope device detachably connected to a processor that converts an image signal corresponding to a subject image read from an element into a video signal and outputs the video signal to the display device, wherein the light guide has at least 2 And the input end of the optical light guide on the processor side is branched for each of the input ends of the at least two optical fiber bundles.
The scope of the electronic endoscope device, wherein the bundle of the two optical fiber bundles forms an emission end of the light guide on the distal end side of the scope as one emission end.