JP2001218728A - Electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope whose body diameter can be reduced. SOLUTION: The electronic edoscope 1 includes the long-sized flexible endoscope body 2. An imaging optical system composed of an objective lens 33 and convex lenses 34 and 35 and a CCD image sensor 5 are installed at the front end 21 of the endoscope body 2. Light distribution lenses 31 and 32 and light emitting diodes 61 and 62 are installed at the front end 21. The light emitting diodes 61 and 62 are so arranged that these diodes exist nearer the front end side of the CCD image sensor 5 and on both sides of the imaging optical system when viewed from an optical axis direction and that the light emitting diodes 61 and 62 partly overlap on the CCD image sensor 5 and do not overlap on the effective imaging regions of the imaging optical system and the CCD image sensor 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope.

[0002]

2. Description of the Related Art Conventionally, for example, in the medical field, an electronic endoscope apparatus has been used for examination and diagnosis of a digestive tract and the like.

[0003] This electronic endoscope apparatus comprises a light emitting element device for an endoscope and an electronic endoscope detachably mounted (connected) to the light emitting element device for an endoscope.

FIG. 11 is a diagram (bottom view and cross-sectional view) showing a distal end portion of a conventional electronic endoscope.

[0005] As shown in FIG.
0 has an endoscope body 110, and the endoscope body 110
A CCD image sensor (imaging element) 130 and a pair of light emitting diodes (light emitting elements) 140, 140 for irradiating the observation site with illumination light are respectively installed at the distal end portion 120.

In this case, the pair of light emitting diodes 14
Reference numerals 0 and 140 are arranged on the sides of the CCD image sensor 130.

[0007] At the tip end of the CCD image sensor 130, an objective lens 150, convex lenses 160 and 17 are provided.
0 is provided.

Further, a light distribution lens (illumination system lens) 180 is provided at the front end side of each light emitting diode 140.

However, the conventional electronic endoscope 10
0, each light emitting diode 140 is arranged on the side of the CCD image sensor 130, so that the endoscope main body 12
There is a disadvantage that the diameter of 0 becomes large.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic endoscope capable of reducing the diameter of an endoscope body.

[0011]

This and other objects are achieved by the present invention which is defined below as (1) to (19).

(1) An image pickup section having an image pickup element, an image pickup optical system provided at the end of the image pickup section, and a light emitting section having a light emitting element for irradiating illumination light to an observation site are provided at the end. An electronic endoscope having the light emitting unit, which is located on the distal end side of the imaging unit, and when viewed from the optical axis direction of the imaging optical system, at least a part of the light emitting unit is the imaging unit. An electronic endoscope, wherein the electronic endoscope is arranged to overlap with. Thereby, the diameter of the endoscope main body can be reduced.

(2) When viewed from the optical axis direction of the image pickup optical system, at least a part of the light emitting section detects an optically black reference level in an image pickup area of the image pickup device. The electronic endoscope according to the above (1), which is disposed so as to overlap with a light-shielding region for performing the operation. Thereby, the diameter of the endoscope main body can be further reduced.

(3) An image pickup section having an image pickup element, an image pickup optical system provided on the front end side of the image pickup section, and a light emitting section having a light emitting element for irradiating illumination light to an observation site are provided at the front end. An electronic endoscope having the light emitting unit, which is located on the distal end side of the imaging unit, and is projected when the light emitting unit is projected on a plane perpendicular to the optical axis direction of the imaging optical system. An electronic endoscope, wherein at least a part of the region is arranged so as to overlap a projection region when the imaging section is projected on a plane perpendicular to the optical axis direction of the imaging optical system.
Thereby, the diameter of the endoscope main body can be reduced.

(4) In the light emitting section, at least a part of a projection area when the light emitting section is projected on a plane perpendicular to the optical axis direction of the image pickup optical system is included in the image pickup area of the image pickup element. (3) wherein the light-shielding region for detecting the optically black reference level is arranged so as to overlap with a projection region when projected on a plane perpendicular to the optical axis direction of the imaging optical system. An electronic endoscope according to claim 1. Thereby, the diameter of the endoscope main body can be further reduced.

(5) The electronic endoscope according to any one of the above (1) to (4), further comprising a deflecting member on a tip side of the light emitting section.

(6) The electronic endoscope according to any one of (1) to (5), wherein the imaging optical system has a deflecting member.

(7) The light-emitting section is configured such that at least a part of the light-emitting section serves as a light-shielding area for detecting an optically black reference level in an imaging area of the imaging device via the imaging optical system. The electronic endoscope according to any one of the above (1) to (6), wherein the electronic endoscope is arranged so as to overlap a light beam to be imaged. Thereby, the diameter of the endoscope main body can be further reduced.

(8) The light emitting section is disposed at a position outside a light beam which forms an image at an end of an effective image pickup area of the image pickup device via the image pickup optical system. The electronic endoscope according to any one of the above. As a result, it is possible to reliably image the observation site.

(9) An image pickup section provided with an image pickup device, an image pickup optical system provided on the distal end side of the image pickup section, and a plurality of light emitting sections provided with light emitting elements for irradiating illumination light to an observation site. An electronic endoscope provided in a unit, wherein each of the light emitting units is at a distal end side of the imaging unit, and is at least one of the light emitting units when viewed from an optical axis direction of the imaging optical system. An electronic endoscope, wherein a unit is disposed so as to overlap with the imaging unit. Thereby, the diameter of the endoscope main body can be reduced.

(10) Each of the light emitting units has an optically black reference light in an image pickup area of the image pickup element, when viewed from the optical axis direction of the image pickup optical system. The electronic endoscope according to the above (9), which is arranged so as to overlap with a light-shielding region for detecting a level. Thereby, the diameter of the endoscope main body can be further reduced.

(11) An image pickup section having an image pickup element, an image pickup optical system provided on the distal end side of the image pickup section, and a plurality of light emitting sections each having a light emitting element for irradiating an observation portion with illumination light. An electronic endoscope having a light-emitting section, wherein each of the light-emitting sections is located on a tip side of the imaging section, and the light-emitting section is on a surface perpendicular to an optical axis direction of the imaging optical system. At least a part of the projection area when projected is arranged so as to overlap the projection area when the imaging unit is projected on a plane perpendicular to the optical axis direction of the imaging optical system. Electronic endoscope. Thereby, the diameter of the endoscope main body can be reduced.

(12) In each of the light emitting units, at least a part of a projection area when the light emitting unit is projected on a plane perpendicular to the optical axis direction of the image pickup optical system has an image pickup element of the image pickup element. The light shielding area for detecting the optically black reference level of the area is arranged so as to overlap with the projection area when the light shielding area is projected on a plane perpendicular to the optical axis direction of the imaging optical system. An electronic endoscope according to 11). Thereby, the diameter of the endoscope main body can be further reduced.

(13) The electronic endoscope according to any one of the above (9) to (12), further comprising a deflecting member on a tip side of the light emitting section.

(14) The electronic endoscope according to any one of (9) to (13), wherein the imaging optical system has a deflecting member.

(15) Each of the light-emitting portions is provided so that at least a part of the light-emitting portion detects an optically black reference level in an image pickup area of the image pickup device via the image pickup optical system. The electronic endoscope according to any one of the above (9) to (14), wherein the electronic endoscope is arranged so as to overlap with a light beam to be imaged on the light-shielding region. Thereby, the diameter of the endoscope main body can be further reduced.

(16) Each of the light emitting units is disposed at a position outside of a light beam which forms an image at an end of an effective image pickup area of the image pickup device via the image pickup optical system. The electronic endoscope according to any one of (15).
As a result, it is possible to reliably image the observation site.

(17) The number of the light-emitting portions is an even number, and these light-emitting portions are perpendicular to the horizontal scanning direction of the image sensor and pass through a center line passing through the center of the effective image pickup area of the image sensor. The electronic endoscope according to any one of the above (9) to (16), which is arranged so as to be substantially line-symmetric.
Thereby, the observation site can be uniformly illuminated.

(18) The number of the light-emitting portions is an even number, and these light-emitting portions are orthogonal to the horizontal scanning direction of the image pickup device and pass through the center of the effective image pickup area of the image pickup device. , And in the same direction as the horizontal scanning direction of the image sensor, and substantially line symmetric with respect to a second center line passing through the center of the effective imaging area of the image sensor. The electronic endoscope according to any one of the above (9) to (16), wherein Thereby, the observation site can be more uniformly illuminated.

(19) The electronic endoscope according to any one of (1) to (18), wherein the light emitting element is a light emitting diode.

Thus, even if a relatively small light emitting element is used, the observation site can be illuminated with sufficient brightness, which is advantageous for reducing the diameter of the electronic endoscope.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic endoscope according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a block diagram showing a first embodiment of an electronic endoscope of the present invention and a configuration example of an endoscope light source device to which the electronic endoscope is attached (connected), and FIG. FIG. 3 is a block diagram showing a configuration example of a signal processing circuit of the electronic endoscope shown in FIG. 1, and FIG. 3 is a block diagram showing a configuration example of a signal processing circuit of the light source device for an endoscope shown in FIG. FIG. 4 is a diagram (bottom view and cross-sectional view) showing the distal end of the electronic endoscope shown in FIG. 1, and FIG. 5 is a diagram showing the distal end of the electronic endoscope shown in FIG. 1 from the optical axis direction of the imaging optical system. FIG. 2 is a diagram illustrating an endoscope main body, a CCD image sensor, an objective lens, and a light emitting diode when viewed.

For convenience of description, the left-right direction in the cross-sectional view of FIG. 4 is "optical axis direction of the imaging optical system", the left side is "tip",
The right side will be described as “base end”.

As shown in FIG. 1, an electronic endoscope device (endoscope device) 300 is detachably mounted (connected) to the endoscope light source device 8 and to the endoscope light source device 8. And an electronic endoscope 1.

The electronic endoscope 1 is provided with an elongated endoscope main body 2 having flexibility (flexibility). The endoscope main body 2 has an operation unit 23 at a base end thereof.

As shown in FIG. 4, an imaging optical system composed of an objective lens 33 and convex lenses 34 and 35 is provided at the center (central portion) of the distal end portion 21 of the endoscope main body 2, and light is used as an imaging unit. A CCD (Charge Coupled Device) image sensor (imaging element) 5 having a transparent (transparent) cover glass 51 is provided, respectively. These are directed from the distal end side (left side in FIG. 4) to the proximal end side (right side in FIG. 4) from the objective lens 33, the convex lens 34, and the convex lens 3.
5. CCD image sensors 5 are arranged in this order.
That is, an imaging optical system is arranged on the tip side of the CCD image sensor 5.

The objective lens 33 is constituted by a concave lens, and the diameter of the objective lens 33 is the largest among the above-mentioned imaging optical systems.

As shown in FIGS. 4 and 5, the entire shape of the CCD image sensor 5 except for the leads 54 is as follows.
It is almost rectangular parallelepiped.

As shown in FIG. 5, the shape of the image pickup area 521 of the CCD image sensor 5 is a rectangle (quadrangle).

A pair of short sides (sides located at both ends in the horizontal scanning direction) 53a and 53b of the image pickup area 521 are respectively provided with strip-shaped light-shielding areas (FIG. 4) for optically detecting a black reference level. 5 (shaded portions) 522 and 523 are provided. Each of the light shielding regions 522 and 523 is usually
"Optical Black (Optical Black)"
Called. Note that a portion of the imaging region 521 other than the light shielding regions 522 and 523 is an effective imaging region (effective imaging region) 524.

In this embodiment, the light shielding regions 522 and 5
The dimensions of 23 are such that the width of the light-shielding region 522 is
3a, the width of the light-shielding region 523 is
The width is set to be constant in the direction b and the width of the light-shielding region 522 is equal to the width of the light-shielding region 523.

As shown in FIGS. 4 and 5, the optical axis O of the imaging optical system passes through the center 525 of the effective imaging area 524, and the CCD image sensor 5 includes the light shielding areas 522 and 523. Are arranged symmetrically with respect to the optical axis O.

As shown in FIG. 4, a pair of light distribution lenses (illumination lenses) 3 are provided at the distal end 21 of the endoscope body 2.
1 and 32 and a pair of light emitting diodes (light emitting elements) 61 and 62 that emit (irradiate) white light are provided, respectively. The light distribution lenses 31 and 32 are respectively
It is arranged on the tip side of the light emitting diodes 61 and 62.

Each of the light distribution lenses 31 and 32 is composed of a convex lens.
And 32 have diameters substantially equal to the diameters of the light emitting diodes 61 and 62, respectively. That is, when viewed from the optical axis direction of the image pickup optical system (hereinafter, referred to as “optical axis direction”), the light emitting diodes 61 and 62 are almost the same as the light distribution lenses 31 and 32, respectively.

The light emitting diode 61 constitutes one light emitting section, and the light emitting diode 62 constitutes the other light emitting section.

The light-emitting element of the present invention has a size that can be set at the tip of the electronic endoscope.
For example, a lamp that emits light when a heating element is energized may be used, but the light emitting diode is preferable because it is small in size, has a semi-permanent life, and consumes little power.

Next, the arrangement of the light emitting diodes 61 and 62 will be described. As shown in FIG. 4, each of the light emitting diodes 61 and 62 is connected to the CCD image sensor 5 respectively.
The image pickup optical system (objective lens 33, convex lenses 34 and 35), which is more distal and viewed from the optical axis direction
Is located on both sides of it.

As shown in FIG. 5, when viewed from the optical axis direction, each of the light emitting diodes 61 and 62 has a part of the light emitting diode 61 and a part of the light emitting diode 62, respectively. The light emitting diodes 61 and 62 are arranged so as not to overlap with the sensor 5 and with the imaging optical system (the objective lens 33 and the convex lenses 34 and 35) and the effective imaging area 524.

That is, each of the light emitting diodes 61 and 6
Reference numerals 2 each denote a light emitting diode 61 at a position outside a light beam that forms an image at an end of the effective imaging area 524 of the CCD image sensor 5 via the imaging optical system and when viewed from the optical axis direction. Part and a part of the light emitting diode 62,
Each is arranged so as to overlap with the CCD image sensor 5.

In this case, in the present embodiment, when viewed from the optical axis direction, each of the light emitting diodes 61 and 62 has a part of the light emitting diode 61 overlapping the light shielding area 522 and a part of the light emitting diode 62 being light shielding. It is arranged so as to overlap with the region 523.

Further, these light emitting diodes 61 and 62 are orthogonal to the horizontal scanning direction of the CCD image sensor 5 and are symmetrical with respect to a first center line (straight line) 55 passing through the center 525 of the effective image pickup area 524. And is arranged in the same direction as the horizontal scanning direction and symmetrically with respect to a second center line (straight line) 56 passing through the center 525 of the effective imaging area 524.

As described above, the number of light emitting diodes is set to an even number equal to or more than two (two in this embodiment), and these are arranged so as to be symmetrical with respect to the center lines 55 and 56, respectively. Can be more uniformly illuminated.

As shown in FIG. 1, one end of a cord-like connecting tube 25 is connected to the base end of the endoscope main body 2.

At the other end of the connecting tube 25, a connecting portion 26 having a connector 27 is provided. With this connector 27, the electronic endoscope 1 and the endoscope light source device 8 are detachably and electrically connected.

The signal processing circuit 7 electrically connected to the connector 27 is built in the connection section 26. The CCD image sensor 5 is connected to the signal processing circuit 7 via signal lines 47 and 48. Is electrically connected to

Each of the light emitting diodes 61 and 6
2 are electrically connected to the connector 27 via lead wires 41 and 42, respectively.

As shown in FIG. 2, the signal processing circuit 7 of the electronic endoscope 1 comprises a sample hold / color separation circuit 71 and a CCD process circuit (clamp means) 72.
, A television timing generator 73, a CCD timing generator 74, and a buffer 75.

As shown in FIG. 1, the endoscope light source device 8
Is a lighting power supply unit 81, a system control circuit (control means) 85, a dimming circuit 86, and a signal processing circuit 9
And a casing (not shown) for accommodating them.

As shown in FIG. 3, the signal processing circuit 9 of the endoscope light source device 8 includes a matrix circuit 91, a gamma correction circuit 92, an aperture correction circuit 93, an A / D converter 94, Generator 95 and memory 96
, A D / A converter 97, a buffer 98, and a matrix encoder / buffer circuit 99.

A television monitor (display means) 400 for displaying an image of an observation site is detachably connected to the endoscope light source device 8.

Next, the operation of the electronic endoscope 300 will be described. As shown in FIG. 1, when the power is turned on, power is supplied from the illumination power supply unit 81 to the light emitting diodes 61 and 62 via the lead wires 41 and 42, whereby the light emitting diodes 61 and 62 emit light. I do. In this case, the voltage level of the lighting power supply unit 81 is
, And alternately switched between a high level and a low level (0 volt) by the system control circuit 85. That is, the voltage of the illumination power supply unit 81 has a continuous pulse shape. The drive control of the illumination power supply unit 81 will be described later.

The illumination light (light flux) from the light emitting diodes 61 and 62 is once converged (condensed) by the light distribution lenses 31 and 32, diverges again, and radiated to the observation site (subject).

The reflected light from the observation site is transmitted by the imaging optical system (objective lens 33, convex lenses 34 and 35) to CC
It is guided so as to form an image on the imaging surface 52 of the D image sensor 5 (see FIGS. 1, 4 and 5).

On the other hand, as shown in FIG. 2, in the television timing generator 73 of the signal processing circuit 7 of the electronic endoscope 1, the horizontal synchronizing signal (HD) and the vertical synchronizing signal (VD)
Are generated. The horizontal synchronizing signal (HD) and the vertical synchronizing signal (VD) are supplied to the CCD process circuit 72 and the CCD
It is input to the timing generator 74.

The television timing generator 73
1, a synchronization signal (Sync) is generated. As shown in FIGS. 1 and 3, the synchronization signal (Sync) is supplied to the timing generator 95 and the system control circuit 85 of the signal processing circuit 9 of the endoscope light source device 8. Is input to

As shown in FIG. 2, in the CCD timing generator 74, each drive signal for driving the CCD image sensor 5 based on the horizontal synchronization signal (HD) and the vertical synchronization signal (VD) from the television timing generator 73. Are generated, and these drive signals are output from the signal processing circuit 7 via the buffer 75.

The CCD timing generator 74
Then, a sample hold signal (SHP) is generated and input to the sample hold color separation circuit 71.

As shown in FIG. 1, the drive signal output from the signal processing circuit 7 is input to the CCD image sensor 5 via a signal line 47, and the CCD image sensor 5 is driven based on the drive signal. . By driving the CCD image sensor 5, an image of the observation site, that is, an image of the observation site formed on the imaging surface 52 is captured.
A CCD signal is output from the CD image sensor 5. This CCD signal is input to the signal processing circuit 7 via the signal line 48.

As shown in FIG. 2, in the sample hold color separation circuit 71 of the signal processing circuit 7, C
The CCD signal is separated into signals for each of R (red), G (green), and B (blue) by a sample hold signal (SHP) from the CD timing generator 74. The R, G, and B signals are input to the CCD process circuit 72, respectively.

The CCD timing generator 74
5, the R, G, and B signals from the pixels corresponding to one of the light-shielding regions 522 and 523 (for example, the light-shielding region 522) are synchronized with the timing at which the signals are input to the CCD process circuit 72. Then, the clamp signal (Cla)
mp) is generated and input to the CCD process circuit 72.

In the CCD process circuit 72, the clamp process is performed once in one horizontal scan in synchronization with the clamp signal (Clamp).

In the clamp processing, the clamp signal (C
R, G, and B signals are sampled in synchronization with (lamp). That is, by sampling the R, G, and B signals from the pixels in the portion corresponding to the light-shielding region 522, an optically black reference level is detected and held.

In this embodiment, the CCD process circuit 72
Has a capacitor (not shown) as holding means for holding the reference level, and charges (voltage) having a magnitude corresponding to the reference level are stored in this capacitor. The reference level can be grasped from the voltage value of the capacitor.

As shown in FIG. 2, in the CCD process circuit 72, the reference level is subtracted from the R, G, and B signals from the pixels in the portion corresponding to the effective imaging area 524, and R, G, B signals are obtained, and two color difference signals (RY, B-
Y) and a luminance signal (Y) are generated. in this way,
By subtracting the reference level from each of the R, G, and B signals, unnecessary signal components such as a dark current component of the CCD image sensor 5 are removed from these signals, whereby an appropriate image can be obtained. Obtainable.

As shown in FIG. 3, these color difference signals (R-
Y), the color difference signal (BY) and the luminance signal (Y)
The signal is output from the CD process circuit 72 and is input to the matrix circuit 91 of the signal processing circuit 9 of the endoscope light source device 8.

Further, as shown in FIG. 1, the luminance signal (Y) is also input to the dimming circuit 86 and used for adjusting the amount of illumination light.

That is, the system control circuit 85
The dimming circuit 86 receives a dimming reference voltage (Vref), and the dimming circuit 86 generates a control signal based on the reference voltage (Vref) and the luminance signal (Y). The driving of the illumination power supply unit 81 is controlled by the control signal. As a result, the ratio (duty ratio) between the period in which the voltage level of the illumination power supply unit 81 indicates the high level and the period in which the voltage level indicates the low level (0 volt) is adjusted as needed, and the amount of illumination light becomes an appropriate value. .

As shown in FIG. 3, in the matrix circuit 91, the color difference signal (RY), the color difference signal (BY), and the luminance signal (Y) are converted into R, G, and B signals. You.

The R signal, G signal and B signal are corrected by a gamma correction circuit 92, further corrected by an aperture correction circuit 93, and input to an A / D converter 94.

The A / D converter 94 converts the R, G, and B signals supplied in the form of analog signals into digital signal forms.

The R signal, G signal and B signal are once written in the memory 96. The memory 96 stores the R
The signal, G signal, and B signal may be subjected to, for example, processing such as freeze.

From the memory 96, the R signal, G signal
The signal and the B signal are read and input to the D / A converter 97.

In the D / A converter 97, the R, G and B signals supplied in digital signal form are converted into analog signal form.

The R signal, G signal and B signal are input to a buffer 97 and a matrix encoder / buffer circuit 98, respectively.

Matrix encoder / buffer circuit 9
8, a luminance signal (Y), a luminance signal (Y) based on an R signal, a G signal, and a B signal from the D / A converter 97 and a synchronization signal (Sync) from the timing generator 95.
Chroma signal (C) and composite signal (Compo)
site) are generated and output to an output terminal (not shown).

The R signal, G signal and B signal from the D / A converter 97 and the synchronization signal (Sync) from the timing generator 95 are stored in a buffer 98.
Via the TV monitor 400.

On the television monitor 400, a color image (electronic image) picked up by the CCD image sensor 5, that is, an endoscope image of a color moving image is displayed.

As described above, according to the electronic endoscope 1, each of the light emitting diodes 61 and 62 is located on the distal end side of the CCD image sensor 5 and when viewed from the optical axis direction. Since a part of the light emitting diodes 61 and 62 are arranged so as to overlap with the light shielding regions 522 and 523, respectively, the diameter of the endoscope main body 2 is reduced.
In particular, the diameter of the tip 21 can be reduced.

Therefore, when the electronic endoscope 1 is applied to a medical electronic endoscope, the burden on the patient can be reduced by reducing the diameter of the endoscope main body 2.

Next, a second embodiment of the electronic endoscope according to the present invention will be described. FIG. 6 is a plan view showing a tip of the electronic endoscope according to a second embodiment of the present invention, and FIG. 7 is a diagram showing the tip of the electronic endoscope shown in FIG. FIG. 2 is a diagram illustrating an endoscope main body, a CCD image sensor, an objective lens, and a light emitting diode when viewed from a direction. The description of the common points with the electronic endoscope 1 of the first embodiment will be omitted, and the main differences will be described.

As shown in these figures, in this electronic endoscope 1, four light distribution lenses (illumination system lenses) 36, 37, 38 and 39 are provided at the distal end 21 of the endoscope main body 2. Four light emitting diodes (light emitting elements) 63, 64, 65, and 66 that emit (irradiate) white light are provided, respectively. Each of the light distribution lenses 36 to 39 is disposed on the tip side of the light emitting diode 63 to 66, respectively.

Each of the light distribution lenses 36 to 39 is composed of a convex lens.
Are substantially equal to the diameters of the light emitting diodes 63 to 66, respectively. That is, when viewed from the optical axis direction, the light emitting diodes 63 to 66 are respectively provided with the respective light distribution lenses 36 to 3.
9 is almost the same.

Next, the arrangement of the light emitting diodes 63 to 66 will be described. As shown in FIG.
66 are located on the distal end side of the CCD image sensor 5 and at each corner of the CCD image sensor 5 when viewed from the optical axis direction.

Each of the light emitting diodes 63 to 66 is
When viewed from the optical axis direction, each light emitting diode 6
3 to 66 overlap the CCD image sensor 5, a part of the light emitting diode 63 overlaps the light shielding area 522, a part of the light emitting diode 64 overlaps the light shielding area 523, and a part of the light emitting diode 65 overlaps the light shielding area 523. The light-emitting diodes 66 overlap so that a part of the light-emitting diodes 66 overlaps the light-shielding region 522, and each of the light-emitting diodes 63 to 66 does not overlap the imaging optical system (the objective lens 33 and the convex lenses 34 and 35) and the effective imaging region 524. Are located.

That is, each of the light emitting diodes 63 to 66
Are light-emitting diodes 63 to 66 at positions outside the luminous flux that forms an image at the end of the effective imaging area 524 of the CCD image sensor 5 via the imaging optical system and when viewed from the optical axis direction. All overlap with the CCD image sensor 5, a part of the light-emitting diode 63 overlaps with the light-shielding region 522, a part of the light-emitting diode 64 overlaps with the light-shielding region 523, and a part of the light-emitting diode 65 overlaps with the light-shielding region 523. The diode 66 is arranged so that a part thereof overlaps the light shielding region 522.

Further, the light emitting diodes 63 to 6
Numeral 6 is orthogonal to the horizontal scanning direction of the CCD image sensor 5, is symmetric with respect to a first center line (straight line) 55 passing through the center 525 of the effective imaging area 524, and is in the same direction as the horizontal scanning direction. It is arranged so as to be line-symmetric with respect to a second center line (straight line) 56 passing through the center 525 of the effective imaging area 524.

According to the electronic endoscope 1, the first endoscope described above is used.
The same effect as the electronic endoscope 1 of the embodiment can be obtained.

In the electronic endoscope 1, when viewed from the optical axis direction, all of the light emitting diodes 63 to 66 are C
Since it overlaps with the CD image sensor 5, the diameter of the endoscope main body 2 can be smaller than that of the electronic endoscope 1 of the first embodiment described above.

Next, a third embodiment of the electronic endoscope according to the present invention will be described. FIG. 8 is a cross-sectional view showing a third embodiment of the electronic endoscope of the present invention, showing a distal end portion thereof. FIG. 9 is a CCD image sensor and a first triangular prism of the electronic endoscope shown in FIG. FIG. 4 is a diagram illustrating a light emitting diode, and a second triangular prism.

For convenience of description, the left side in FIGS. 8 and 9 will be described as “distal end” and the right side will be described as “base end”.

The description of the common points with the electronic endoscope 1 of the first embodiment will be omitted, and the main differences will be described.

As shown in these figures, in the electronic endoscope 1, the light emitting diode 61 and the CCD image sensor 5 are provided at the distal end 21 of the endoscope main body 2 in the longitudinal direction of the endoscope main body 2. (Horizontal direction in FIG. 8). The light emitting diode 61 is located on the tip side of the CCD image sensor 5.

The CCD image sensor 5 and the light emitting diode 61 are mounted on the circuit board 11 installed at the tip 21 respectively. The circuit board 1
1, various chip components 12 are mounted.

The CCD image sensor 5 has a light receiving surface 5
8 are arranged so as to face upward in FIG. 8, and an opening 111 is formed in the circuit board 11 at a position where the CCD image sensor 5 is mounted.

The light emitting diode 61 is arranged such that the light emission side is the upper side in FIG. 8, and an opening 112 is formed in the circuit board 11 at a position where the light emitting diode 61 is mounted.

A lens holder 14 is provided at the distal end portion 21 of the endoscope main body 2 and at the distal end side of the opening 111. In the lens holder 14, an objective lens 33, a convex lens 34, 35 are installed.

A first triangular prism (deflecting member) 13 is provided at the base end side of the lens holder 14, that is, at the position of the opening 111. This first triangular prism 13
A reflective film 132 is formed on the surface 131 of the optical disk.

The objective lens 33 and the convex lens 3
The imaging optical system is configured by the fourth and the fourth triangular prisms 13.

A lens holder 16 is provided at the distal end portion 21 of the endoscope main body 2 and at the distal end side of the opening 112. In the lens holder 16, light distribution lenses 151 and 152 are provided. is set up.

A second triangular prism (deflecting member) 17 is provided at the base end side of the lens holder 16, that is, at the position of the opening 112. This second triangular prism 17
The reflective film 172 is formed on the surface 171 of the optical disk.

The light distribution lenses 151 and 152 and the second triangular prism 17 constitute an illumination optical system. Further, a transparent cover glass 18 is provided at the tip of the endoscope main body 2.

The first triangular prism 13 and the second triangular prism 17 are right-angle prisms.

As described above, in the electronic endoscope 1, the projection area 613 when the light emitting diode 61 is projected on the plane (vertical plane) 191 perpendicular to the optical axis direction is the CCD.
It overlaps with the projection area 57 when the image sensor 5 is projected on the vertical plane 191. Thereby, the diameter of the endoscope main body 2 can be reduced.

As shown in FIG. 9, in the light emitting diode 61 and the second triangular prism 17, a part of the second triangular prism 17 forms an image on the light shielding area 522 of the CCD image sensor 5 via the imaging optical system. It is arranged so as to overlap with the light beam.

That is, the light emitting diode 61 and the second
The triangular prism 17 is configured such that a part of a projection area when the light emitting diode 61 (particularly, an effective portion of the light emitting diode 61) is projected on the vertical surface 191 projects a light shielding area 522 of the CCD image sensor 5 onto the vertical surface 191. Are arranged so as to overlap with the projection area of.

Thus, when the part of the second triangular prism 17 does not overlap with the light beam formed on the light shielding area 522, the position of the CCD image sensor 5 can be set to the base end side. For this reason, the position of the lens holder 14 can be set to the lower side in FIG. 9, so that the diameter of the endoscope main body 2 can be reduced, and the CCD image sensor 5 and the light emitting diode 61 are integrated to reduce the size. Can be achieved.

As shown in FIG. 8, in the electronic endoscope 1, the illumination light emitted from the light emitting diode 61
The light is reflected to the tip side by the reflection film 172 of the triangular prism 17.
That is, the illumination light from the light emitting diode 61 is bent by 90 ° by the second triangular prism 17 and is emitted from the second triangular prism 17 toward the tip end.

The illumination light is supplied to the light distribution lenses 151 and 1.
By 52, the light is once converged, diverged again, and irradiated to the observation site.

The light reflected from the observation site is guided by the imaging optical system and the first triangular prism 13 so as to form an image on the imaging surface 52 of the CCD image sensor 5. On this occasion,
The light beam from the imaging optical system is reflected by the reflection film 132 of the first triangular prism 13 downward in FIG. That is, the light beam from the imaging optical system is bent by 90 ° by the first triangular prism 13, exits from the first triangular prism 13 toward the imaging surface 52 of the CCD image sensor 5, and forms an image on the imaging surface 52. .

According to the electronic endoscope 1, the first endoscope described above is used.
The same effect as the electronic endoscope 1 of the embodiment can be obtained.

In the present invention, the number of light emitting units may be plural. When setting the number of light emitting parts to multiple,
As in the above-described first and second embodiments, the light-emitting portions are perpendicular to the horizontal scanning direction of the CCD image sensor 5 and are aligned with the first center line 55 passing through the center 525 of the effective imaging area 524. And the center 52 of the effective imaging area 524 in the same direction as the horizontal scanning direction.
It is preferably arranged so as to be axisymmetric with respect to a second center line 56 passing through the center line 5.

Next, a fourth embodiment of the electronic endoscope according to the present invention will be described. FIG. 10 is a sectional view showing a distal end portion of a fourth embodiment of the electronic endoscope according to the present invention.

For convenience of explanation, the left side in FIG. 10 will be described as “distal end” and the right side will be described as “base end”.

The description of the common points with the electronic endoscope 1 of the third embodiment will be omitted, and the main differences will be described.

As shown in the figure, in the electronic endoscope 1, the second triangular prism 17 is not provided, and the light emitting diode 61 is provided in the lens holder 16.

The light emitting diode 61 is electrically connected to the circuit board 11 through the lead wires 611 and 612.

In the electronic endoscope 1, the light emitting diode 61 and the CCD image sensor 5 overlap when viewed from the optical axis direction.

That is, when the light emitting diode 61 is projected on a plane (vertical plane) 191 perpendicular to the optical axis direction, the projection area 613 forms the CCD image sensor 5 with the vertical plane 19
It overlaps with the projection area 57 when projected on 1.

The light emitting diode 61 is arranged so that a part of the light emitting diode 61 overlaps with a light beam which forms an image on the light shielding area 522 of the CCD image sensor 5 via the imaging optical system.

That is, in the light emitting diode 61, a part of a projection area when the light emitting diode 61 is projected on the vertical surface 191 overlaps a projection area when the light shielding area 522 of the CCD image sensor 5 is projected on the vertical surface 191. Are arranged as follows. Thereby, the diameter of the endoscope main body 2 can be reduced.

According to the electronic endoscope 1, the third endoscope described above is used.
The same effect as the electronic endoscope 1 of the embodiment can be obtained.

The electronic endoscope according to the present invention has been described based on the illustrated embodiments. However, the present invention is not limited to these embodiments. It can be replaced with a configuration.

For example, in the present invention, two of the above embodiments are used.
The above configurations may be appropriately combined.

In the present invention, the endoscope main body 2 may be provided with one or more functional channels.
The functional channel includes, for example, a forceps channel (lumen) through which a treatment tool such as a forceps or a laser treatment tool is inserted, a water supply channel, an air supply channel, and the like.

In the present invention, when viewed from the optical axis direction, the light-emitting portion (light-emitting element) is arranged so as not to overlap with the light-shielding region, and at least a part of the light-emitting portion overlaps with the imaging portion (image-capturing element). It may be.

In the present invention, the number of light-emitting portions is not particularly limited, and may be one, three, or five or more.

However, the number of light emitting portions is preferably two or more, more preferably about 2 to 8, and particularly preferably an even number.

When the number of light-emitting portions is set as described above, it is possible to more uniformly illuminate the observation site.

In each of the above embodiments, a light emitting diode is used as a light emitting element. However, the present invention is not limited to this. For example, the light emitting diode emits light by temperature radiation caused by energizing and heating a heating element. A lamp or the like may be used.

Further, in the present invention, the type of the image pickup device is not particularly limited.
Various types of image sensors (imaging devices) such as an OS type image sensor and a CPD may be used.
Any of a monochrome image sensor may be used.

The electronic endoscope of the present invention can be applied to, for example, a medical electronic endoscope and an industrial electronic endoscope.

[0143]

As described above, according to the electronic endoscope of the present invention, the diameter of the endoscope main body can be reduced.

Thus, when the present invention is applied to a medical electronic endoscope, the burden on the patient can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a first embodiment of an electronic endoscope according to the present invention and a light source device for an endoscope to which the electronic endoscope is attached (connected).

FIG. 2 is a block diagram showing a configuration example of a signal processing circuit of the electronic endoscope shown in FIG.

3 is a block diagram illustrating a configuration example of a signal processing circuit of the endoscope light source device illustrated in FIG. 1;

FIG. 4 is a view (bottom view and cross-sectional view) showing a distal end portion of the electronic endoscope shown in FIG. 1;

FIG. 5 is a diagram showing an endoscope main body, a CCD image sensor, an objective lens, and a light emitting diode when the distal end portion of the electronic endoscope shown in FIG. 1 is viewed from the optical axis direction of the imaging optical system. is there.

FIG. 6 is a second embodiment of the electronic endoscope of the present invention,
It is a top view which shows the front-end | tip part.

FIG. 7 is a diagram showing an endoscope main body, a CCD image sensor, an objective lens, and a light emitting diode when the distal end portion of the electronic endoscope shown in FIG. 6 is viewed from the optical axis direction of the imaging optical system. is there.

FIG. 8 is a third embodiment of the electronic endoscope of the present invention,
It is sectional drawing which shows the front-end | tip part.

9 is a diagram showing a CCD image sensor, a first triangular prism, a light emitting diode, and a second triangular prism of the electronic endoscope shown in FIG.

FIG. 10 is a cross-sectional view illustrating a distal end portion of a fourth embodiment of the electronic endoscope according to the present invention.

FIG. 11 is a view (bottom view and cross-sectional view) showing a distal end portion of a conventional electronic endoscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic endoscope 2 Endoscope main body 21 End part 23 Operation part 25 Connecting pipe 26 Connection part 27 Connector 31, 32 Light distribution lens 33 Objective lens 34, 35 Convex lens 36-39 Light distribution lens 41, 42 Lead wire 47, 48 signal line 5 CCD image sensor 51 cover glass 52 imaging surface 521 imaging region 522, 523 light shielding region (optical black portion) 524 effective imaging region 525 center 53a, 53b short side 54 lead 55 first center line 56 second center Lines 61 to 66 Light emitting diode 7 Signal processing circuit 8 Endoscope light source device 81 Illumination power supply unit 9 Signal processing circuit 13 First triangular prism 17 Second triangular prism 100 Electronic endoscope 110 Endoscope main body 120 Tip section 130 CCD image sensor 140 Light emitting diode 150 Objective lens 16 , 170 convex 180 light distributing lens 300 electronic endoscope apparatus 400 television monitor O optical axis

Claims (19)

[Claims] An image pickup unit having an image pickup device, an image pickup optical system provided at a distal end side of the image pickup unit, and a light emitting unit having a light emitting element for irradiating an observation part with illumination light are provided at a distal end portion. An electronic endoscope, wherein the light emitting unit is on the distal end side of the imaging unit, and
An electronic endoscope, wherein at least a part of the light emitting unit is disposed so as to overlap with the imaging unit when viewed from an optical axis direction of the imaging optical system. 2. The light emitting unit, wherein at least a part of the light emitting unit detects an optically black reference level in an image pickup area of the image pickup device when viewed from an optical axis direction of the image pickup optical system. The electronic endoscope according to claim 1, wherein the electronic endoscope is disposed so as to overlap with a light-shielding region for the purpose. 3. An image pickup unit having an image pickup device, an image pickup optical system provided at a front end side of the image pickup unit, and a light emitting unit having a light emitting element for irradiating illumination light to an observation site are provided at the front end. An electronic endoscope, wherein the light emitting unit is on the distal end side of the imaging unit, and
At least a part of a projection area when the light emitting unit is projected on a plane perpendicular to the optical axis direction of the imaging optical system, the imaging unit is placed on a plane perpendicular to the optical axis direction of the imaging optical system. An electronic endoscope, wherein the electronic endoscope is arranged so as to overlap with a projection area at the time of projection. 4. The light emitting section, wherein at least a part of a projection area when the light emitting section is projected on a plane perpendicular to an optical axis direction of the imaging optical system, includes: 4. The image forming apparatus according to claim 3, wherein a light-shielding region for detecting an optically black reference level is arranged so as to overlap a projection region when the light-shielding region is projected on a plane perpendicular to the optical axis direction of the imaging optical system. Electronic endoscope. 5. The electronic endoscope according to claim 1, further comprising a deflecting member on a tip side of said light emitting section. 6. The electronic endoscope according to claim 1, wherein the imaging optical system has a deflecting member. 7. The light emitting section, wherein at least a part of the light emitting section is connected to a light shielding area for detecting an optically black reference level in an imaging area of the imaging device via the imaging optical system. The electronic endoscope according to any one of claims 1 to 6, wherein the electronic endoscope is arranged so as to overlap a light beam to be imaged. 8. The imaging device according to claim 1, wherein the light-emitting unit is disposed at a position outside a light beam that forms an image at an end of an effective imaging area of the imaging device via the imaging optical system. An electronic endoscope according to claim 1. 9. An image pickup unit provided with an image pickup device, an image pickup optical system provided at a front end side of the image pickup unit, and a plurality of light emitting units provided with a light emitting element for irradiating an observation site with illumination light. In the electronic endoscope having, each of the light emitting units, respectively, is a tip side from the imaging unit, and when viewed from the optical axis direction of the imaging optical system,
An electronic endoscope, wherein at least a part of the light emitting unit is disposed so as to overlap with the imaging unit. 10. Each of the light emitting units has an optically black reference level in an image pickup area of the image pickup device, at least a part of which is viewed from the optical axis direction of the image pickup optical system. The electronic endoscope according to claim 9, wherein the electronic endoscope is arranged so as to overlap with a light-shielding region for detecting an image. 11. An image pickup section provided with an image pickup device, an image pickup optical system provided on a front end side of the image pickup section, and a plurality of light emitting sections provided with a light emitting element for irradiating illumination light to an observation site. Wherein each of the light emitting units is located on the tip side of the imaging unit, and projects the light emitting unit on a surface perpendicular to the optical axis direction of the imaging optical system. Wherein at least a part of the projection area when the projection is performed is arranged so as to overlap a projection area when the imaging unit is projected on a plane perpendicular to the optical axis direction of the imaging optical system. Endoscope. 12. Each of the light emitting units has at least a part of a projection area when the light emitting unit is projected on a plane perpendicular to an optical axis direction of the imaging optical system, and the imaging area of the imaging element 12. The light-shielding area for detecting an optically black reference level is arranged so as to overlap a projection area when the light-shielding area is projected on a plane perpendicular to the optical axis direction of the imaging optical system. An electronic endoscope according to claim 1. 13. The electronic endoscope according to claim 9, further comprising a deflecting member on a tip side of said light emitting section. 14. The electronic endoscope according to claim 9, wherein the imaging optical system has a deflecting member. 15. The light-emitting unit according to claim 1, wherein at least a part of the light-emitting unit is light-shielded for detecting an optically black reference level in an imaging region of the imaging device via the imaging optical system. The electronic endoscope according to any one of claims 9 to 14, wherein the electronic endoscope is arranged so as to overlap with a light beam that forms an image in a region. 16. The image forming apparatus according to claim 9, wherein each of the light emitting units is arranged at a position outside of a light beam which forms an image at an end of an effective image pickup area of the image pickup device via the image pickup optical system. An electronic endoscope according to any one of the above. 17. The number of the light emitting units is an even number, and these light emitting units are substantially perpendicular to a center line that is orthogonal to a horizontal scanning direction of the image sensor and passes through a center of an effective imaging area of the image sensor. The electronic endoscope according to any one of claims 9 to 16, wherein the electronic endoscope is arranged to be line-symmetric. 18. The number of the light-emitting portions is an even number, and these light-emitting portions are perpendicular to a horizontal scanning direction of the image sensor and extend along a first center line passing through the center of an effective imaging area of the image sensor. With respect to a second center line passing through the center of the effective imaging region of the image sensor in the same direction as the horizontal scanning direction of the image sensor. The electronic endoscope according to any one of claims 9 to 16, wherein the electronic endoscope is arranged. 19. The electronic endoscope according to claim 1, wherein the light emitting element is a light emitting diode.