JP4578608B2 - Endoscope system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an endoscope system provided with illumination means for endoscopically examining a body cavity or the like.
[0002]
[Prior art]
Conventionally, as disclosed in Japanese Patent Laid-Open No. 6-78311, the brightness of a subject is detected to control the aperture of the illumination device, and when the aperture is insufficient, the video signal level is changed by switching the video system gain. A technique for changing the brightness and adjusting the brightness has been proposed.
[0003]
Japanese Patent Laid-Open No. 6-78312 proposes a technique for adjusting the brightness of the entire screen by detecting the halation portion of the screen and changing the gain of the output signal of the entire screen.
However, in the case of an endoscope, the subject is not flat, and there are many earthen tubular subjects such as irregularities and lumens. If there are only irregularities, the technique disclosed in Japanese Patent Laid-Open No. 6-78331 may be improved. However, in the case of an earthen tubular subject such as a lumen, the center of the screen is a distant view and the screen is dark, and the periphery of the screen is a close view. Therefore, it is brightly imaged.
[0004]
[Problems to be solved by the invention]
In extreme cases, there is a problem that if the brightness of the periphery of the screen is adjusted to an appropriate brightness, the distant portion at the center becomes extremely dark. In the case of an endoscope, illumination light is emitted from an illumination lens provided at the distal end of the endoscope through a light guide provided inside the endoscope from an external light source device. Due to the characteristics of the structure, the light distribution characteristic is bright at the center of the screen and dark at the periphery of the screen. In this case, the center of the screen becomes extremely bright even when observing a flat subject, or the periphery of the screen is extremely It sometimes got dark.
[0005]
Thus, when observing a patient's body with an endoscope, the state changes from the center of the screen toward the periphery, and thus there has been a need to ensure brightness matching those.
[0006]
    (Object of invention)
  The present invention has been made in view of the above-described points. By enabling adjustment of an image of a subject that changes from the center of the screen toward the periphery, a good image can be obtained over the entire image display area.Also suitable for imaging the same part under the same conditions in different states over timeAn object is to provide an endoscope system.
[0007]
[Means for Solving the Problems]
  The present inventionAn endoscope having an image means and an illumination means;
  SaidFor imaging the signal from the imaging meansGenerate video signal and output to display deviceVideo signal converting means;
  In an endoscope system having
  SaidDisplayed on the display deviceAs an image of the subject corresponding to the video signalImage characteristics that change from the center to the periphery of the display area of the endoscopic image can be adjusted from the center to the periphery of the display areaWith multiple amplifier circuits with different amplification characteristicsImage adjustment meansWhen,
    Selection means for selecting an amplification circuit to be used for amplification of the video signal from the plurality of amplification circuits;
  Image recording means for recording the information of the amplifier circuit actually selected and used in the image adjustment means together with the endoscopic image,
  Using the information recorded in the image recording means, in the next endoscopy, when imaging the same part as the previous time when the information was recorded, it was possible to select and use the same amplification circuit as the previous timeIt is characterized byRu.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
1 to 6 relate to a first embodiment of the present invention, FIG. 1 shows an overall configuration of an endoscope system according to the first embodiment of the present invention, and FIG. 2 shows a configuration of an image adjustment unit. 3 shows the amplification characteristics of the amplifier circuit, and FIG. 4 shows a representative position on the display surface of the monitor and a solid-state imaging device in which pixels for detecting the luminance distribution are set correspondingly. FIG. 6 is an explanatory diagram illustrating an operation when a flat subject is imaged, and FIG. 6 is an explanatory diagram illustrating an operation when a luminal subject is imaged.
[0009]
As shown in FIG. 1, an endoscope system 1 according to a first embodiment of the present invention includes an electronic endoscope 2 incorporating an image sensor and illumination light transmission means for the illumination light transmission means of the electronic endoscope 2. A light source device 3 to be supplied, a camera control unit (abbreviated as CCU) 4 as an imaging means for performing signal processing on the image sensor, an image adjustment unit 5 connected to the CCU 4 and performing image adjustment, and an output from the CCU 4 And a monitor 6 as a display device for displaying a standard video signal.
[0010]
The electronic endoscope 2 has an elongated insertion portion 7, and a light guide 8 as an illumination light transmission means is inserted into the insertion portion 7, and a connector 9 at the rear end of the light guide 8 is attached to and detached from the light source device 3. The illumination light that is freely connected and supplied from the light source device 3 is transmitted by the light guide 8. The distal end surface of the light guide 8 is fixed to the distal end portion 10 of the insertion portion 7, and is emitted forward from the distal end surface through an illumination optical system 11 attached to the illumination window, and is directed toward the subject 12 such as the affected portion in the body cavity. Illuminate.
[0011]
The distal end portion 10 is provided with an observation window adjacent to the illumination window. An objective optical system 13 is attached to the observation window, and an optical image of the illuminated subject 12 is formed. A solid-state imaging device 14 such as a charge coupled device (abbreviated as CCD) is disposed at the imaging position of the objective optical system 13 to form an imaging device 15 that captures a subject image.
[0012]
The solid-state imaging device 14 is connected to a drive circuit 17 and a preprocess circuit 18 of the CCU 4 via a signal cable 16. The drive circuit 17 generates a drive signal and applies it to the solid-state image sensor 14, and the photoelectrically converted image signal is input to the preprocess circuit 18.
[0013]
As shown in FIG. 2, the preprocess circuit 18 includes an amplifier 19 that amplifies an imaging signal, and a CDS circuit 20 that performs sampling processing that extracts a signal component of a pixel portion from the amplified signal.
[0014]
An output signal of the preprocess circuit 18 is input to an image adjustment circuit 21 constituting the image adjustment unit 5. The image adjustment circuit 21 is also connected to an image adjustment value input unit 22 for manual setting. When manual setting is selected, the image adjustment circuit 21 has a characteristic corresponding to the image adjustment value set by the image adjustment value input unit 22. Convert to an adjusted signal.
[0015]
Specifically, an analog signal input from the pre-process circuit 18 is read, and a video signal changing from the center to the periphery of the screen is monitored, processed to a desired characteristic desired by the user, and returned to the CCU 4.
[0016]
The image adjustment circuit 21 is connected to the image adjustment input unit 22, and in addition to the characteristic automatically processed by the image adjustment circuit 21, the user can arbitrarily set the characteristic set by the image adjustment input unit 22 when manual setting is selected. The image level can be processed.
[0017]
The output signal of the image adjustment circuit 21 is input to the post-processing circuit 23 of the CCU 4, converted into a standard video signal and output to the monitor 6, and the subject image is displayed on the display surface of the monitor 6.
[0018]
As shown in FIG. 2, the image adjustment circuit 21 receives an output signal from the CDS circuit 20, receives an A / D conversion circuit 31 for A / D conversion, and a frame memory 32 for temporarily storing the A / D converted signal. A changeover switch 33 that performs switching so that the characteristics can be changed, and amplification circuits A to E 34A to 34E having the characteristics shown in FIG. 3 connected to the contacts a to e selected by the changeover switch 33; Amplifying circuits A to E An enhancement circuit 35 that emphasizes the contours of the signals amplified by 34A to 34E, a color correction circuit 36 that performs color correction, a D / A conversion circuit 37 that performs D / A conversion, and a frame memory 32 Automatic selection circuit 38 for automatically selecting amplification circuits A to E 34A to 34E to be used from the output signal and automatic / manual switching inserted in the middle of switching between the output terminal of the image adjustment input unit 22 and the changeover switch 33 A switch 39, and an input switching circuit (or input switch) 40 for switching the changeover switch 33 automatically / manually by switch setting by a user.
[0019]
When the automatic switching is selected by operating the input switching circuit 40, the contact a of the automatic / manual switching switch 39 is turned on. When the manual switching is selected, the contact b of the automatic / manual switching switch 39 is turned on. Like to do.
[0020]
In the present embodiment, as shown in FIG. 3, an amplifier circuit A that makes it possible to smoothly adjust image characteristics, in this case, luminance characteristics, concentrically from the center O of the display screen of the monitor 6 serving as a display device toward the periphery thereof. -E 34A-34E are provided.
[0021]
FIG. 3 shows the characteristics of the amplifier circuits A to E 34A to 34E. In FIG. 3, reference numerals 34A to 34E are omitted.
The amplification circuits A to E 34A to 34E are set to a plurality of amplification pattern levels, and the luminance levels are set to the characteristics shown in FIGS. 3A to 3E with respect to the state of the original image stored in the frame memory 32. It is converted and output.
[0022]
3A is a circuit having a flat characteristic for outputting the original image as it is, FIG. 3B is a circuit having a characteristic for increasing the luminance gain as it goes to the periphery of the screen, and FIG. 3C is similar to FIG. (D) is a circuit with a characteristic in which the luminance gain is increased toward the center of the screen, and (E) is the same as (D) but more emphasized than (D). I have to. The image level state is set as shown in (A) to (E), for example, but is not necessarily limited to this.
[0023]
Next, a method of automatically determining the state of the original image by the automatic selection circuit 38 and switching the image processing level will be described.
As shown in FIG. 4A, the average value of a plurality of pixels at each corresponding position in the solid-state image sensor 14 shown in FIG. 4B so as to correspond to the center position, the peripheral position, and the intermediate position of the monitor 6. The state of the luminance level distribution of the original image is determined by monitoring the signal and comparing the average level.
Then, as will be described later, the distribution characteristics of the luminance level distribution of the original image are changed by the amplification circuits A to E 34A to 34E according to the determination result, so that the characteristics can be improved to be easily observed. .
[0024]
Next, the operation of the present embodiment will be described first with reference to FIG.
As shown in FIG. 1, the electronic endoscope 2, the light source device 3, the CCU 4, the image adjustment unit 5, and the monitor 6 are connected and turned on.
[0025]
Then, the illumination light from the light source device 3 is transmitted by the light guide 8, and the subject 12 illuminated by the illumination optical system 11 is imaged on the solid-state imaging device 14, and the subject image is displayed on the monitor 6 via the CCU 4 and the image adjustment unit 5. Will be displayed.
[0026]
FIG. 5A shows a state when a flat subject is observed with the electronic endoscope 2. FIG. 5B shows a state where the imaging state in FIG. 5A is displayed as a video signal (luminance signal).
[0027]
In the prior art, since a flat subject is observed, the center of the image is bright because the distance is shorter than the peripheral part, and the periphery is dark because the distance is long. Moreover, since the light amount from the light source device 3 is higher in the center than in the periphery, this tendency is further promoted.
[0028]
Conventionally, as indicated by an amplification circuit A 34A, a signal obtained by multiplying a signal from a subject by a coefficient at a substantially constant rate from the center to the periphery of the screen is output.
[0029]
Therefore, as shown in FIG. 5C, the image displayed on the monitor 6 as a display device may be bright at the center of the screen and dark at the periphery, and the peripheral portion is too dark for observation on the entire screen, making it difficult to identify. .
[0030]
In the present embodiment, when the user sets automatic selection by the input switching circuit 40, the luminance level distribution of the video signal input to the automatic selection circuit 49 is judged, and the characteristics are more suitable for observation. One amplifying circuit is selected from the amplifying circuits A to E 34A to 34E so as to automatically change to the characteristics to be changed.
[0031]
That is, the characteristic (state) of the luminance signal level of the original image is judged by the automatic selection circuit 38, one of the amplification circuits A to E 34A to 34E by the changeover switch 33 is automatically selected, and the selected amplification circuit is selected. Is used to process the signal and improve its characteristics.
[0032]
For example, when the characteristic of the original image is the state (characteristic) of FIG. 5B, the automatic selection circuit 38 determines that the luminance level of the peripheral part tends to be lower than the central part. The amplifier circuit having an amplification characteristic that improves the frequency is selected. Specifically, the amplifier circuit B 34B or the amplifier circuit C 34C having the amplification characteristic shown in FIG. 3B or 3C is selected, and FIG. The characteristics shown in
[0033]
That is, when the characteristic of the original image is in the state (characteristic) of FIG. 5B, the level of the luminance signal is raised at the peripheral part with respect to the center of the screen. As a result, the monitor 6 can realize a brightness almost flat from the center to the periphery of the screen as shown in FIG. 5E from the characteristics of FIG.
[0034]
When the user sets automatic selection by the input switching circuit 40, the change-over switch 33 is in a state where it can be manually switched, and when one of the amplifiers A to E 34A to 34E is selected, If the amplification circuit 34B or 34C having the amplification characteristic shown in FIG. 3B or 3C is selected from the image quality adjustment input unit 22, the characteristic shown in FIG. 5D can be improved.
[0035]
In addition, the case shown in FIG. 6A shows a state in which a lumen-shaped portion is observed (endoscopic examination). FIG. 6B shows a state in which the imaging state in FIG. 6A is displayed as a video signal (luminance signal).
[0036]
In this case, the central side is dark and the peripheral side is bright. In this case, the image displayed on the monitor 6 is dark at the center of the screen and bright at the periphery as shown in FIG. In some cases, the center is dark and difficult to identify.
[0037]
In this case, when the user sets automatic selection by the input switching circuit 40, the luminance level distribution of the video signal input to the automatic selection circuit 49 is determined, and the characteristic is considered to be more suitable for observation. One amplifier circuit is selected from the amplifier circuits A to E 34A to 34E so as to be automatically changed. Specifically, the amplifier circuit D 34D of FIG. 3D or the amplifier circuit E 34E of FIG. 3E is selected, and the characteristics of FIG. 6B are processed into the characteristics of FIG. 6D.
[0038]
Then, the monitor 6 can realize brightness almost flat from the center to the periphery of the screen as shown in FIG. 6E from the characteristic of FIG. 6C.
[0039]
In addition, when the user sets automatic selection by the input switching circuit 40, the selector switch 33 can be manually switched and set, and when selecting one of the amplifier circuits A to E 34A to 34E, If the amplification circuit D 34D or the amplification circuit E 34E having the amplification characteristics shown in FIG. 3D or 3E is selected from the image quality adjustment input unit 22, the characteristics shown in FIG. 6D can be improved.
[0040]
As described above, according to the present embodiment, the amplification circuits A to E 34A to 34E having different amplification characteristics are selected automatically or manually according to the luminance level distribution of the original image, so that the signals are selected by the selected amplification circuit. Can be processed, and the characteristic can be improved to obtain an endoscopic image that is easy to observe.
[0041]
The present embodiment has the following effects.
With the above configuration, even if the state of the subject and the light distribution characteristics of the illumination means change, it is possible to adjust the brightness of the screen that matches those states, and it is almost uniform over the entire endoscope screen. A good image with brightness can be obtained.
In addition, it is no longer necessary to rely only on the light distribution characteristics of the lighting means for the brightness characteristics of the screen. An observable endoscope system can be provided.
[0042]
In the above description, the amplifier circuits A to E 34A to 34E shown in FIGS. 3A to 3E are prepared so as to be able to cope with any observation state of FIG. 5 or FIG. Any one of the above can be selected, but a case where a part of them is used also belongs to the present invention.
[0043]
For example, the amplifier circuits A to C 34A to 34C are prepared so as to correspond to the observation state of FIG. 5, or the amplifier circuits A, D, E 34A, 34D, and 34E are prepared to correspond to the observation state of FIG. Or you can do it.
[0044]
In the above description, a plurality of amplifier circuits A to E34A to 34E having different characteristics are prepared in the image adjustment circuit 21 and one of them is selected to make it possible to adjust the image characteristics. An amplification circuit that can adjust the amplification characteristics may be adopted, and the amplification characteristics may be controlled to similarly adjust the image characteristics.
[0045]
In the above-described embodiment, the case where the distance between the tip 10 and the subject is not so small, that is, the case where the deviation between the center of illumination and the center of observation is small has been described. On the other hand, for example, in addition to the amplification circuits A to E 34A to 34E having the characteristics shown in FIG. 3, the distance to the subject is small and the center position between the illumination and the observation is shifted. An amplifier circuit having the above characteristics may be prepared so that one of them can be selected.
[0046]
More specifically, in addition to the characteristics shown in FIG. 3, for example, as shown in FIG. 1, the illumination optical system 11 is on the upper side and the objective optical system 13 is on the lower side, so that it is adjacent in the vertical direction ( In the case of an arranged structure, if the distance to the subject is small and there is a deviation in the center position between the illumination and the observation, this corresponds to the center of the illumination on the observation screen. It is preferable that an amplifier circuit having characteristics centered on the position can be selected.
[0047]
That is, corresponding to the case where the distance to the subject is small, an amplifier circuit set to, for example, a concentric characteristic around the position above the center O of the monitor 6 in FIG. 3 can be selected, and from that state to the subject As the distance increases, an amplification circuit set to a concentric characteristic centering on a position close to the center O of the monitor 6 can be selected so that the illumination characteristic by the illumination means may be flattened. In this way, when observing a flat subject when the distance is small, an image suitable for observation can be obtained.
[0048]
In addition, when performing endoscopy, it may be desirable to obtain endoscopic images of the same part in different states in order to examine the healing state. For this purpose, images should be taken under the same conditions. Is desirable.
For this reason, when an endoscopic image is recorded by the image recording apparatus, the state of the signal processing system used for imaging may be recorded together with the endoscopic image. Specifically, the information of the selected amplification circuit is recorded together with the endoscopic image, and when the next endoscopy is performed, the information can be used to easily set the same conditions. You may do it.
[0049]
In the above description, the image captured by the solid-state image sensor 14 is displayed on the entire display screen of the monitor 6 in a state where the center of the solid-state image sensor 14 and the center of the display screen of the monitor 6 are matched. did. On the other hand, even when an endoscopic image (subject image) captured by the solid-state imaging device 14 is displayed in a partial area (display area) of the display screen of the monitor 6, the words on the display screen are displayed in the display area. It can be similarly applied by replacing with
[0050]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.
Instead of the luminance level of the first embodiment, correction of a color signal for correcting radial color shading (color unevenness) that changes from the center to the periphery of the screen is performed. In the first embodiment, the luminance signal has been described, but in the second embodiment, attention is paid to the color signal. For this reason, an image adjustment circuit 41 different from the first embodiment is employed. Others are the same.
[0051]
As shown in FIG. 7, in the present embodiment, the output signal of the preprocess circuit 18 is input to the color separation circuit 43 through the A / D conversion circuit 42, and the luminance signal Y and the color difference signals RY and BY are generated. Is input to the frame memory unit 44 and temporarily stored. The frame memory unit 44 includes three frame memories 44a, 44b, and 44c for luminance signals and two color difference signals.
[0052]
The color difference signals RY and BY read from the frame memories 44b and 44c pass through the changeover switches 45a and 45b, respectively, and each color difference amplifier circuit of the subsequent color difference amplifier circuit section 46 (in FIG. 7, for simplification). (Abbreviated as amplifiers a to c, a ′ to c ′) 46a to 46c and 46a ′ to 46c ′. These color difference amplifying circuits 46a to 46c and 46a 'to 46c' are set so that the level of the color difference is changed concentrically from the center to the periphery of the screen.
[0053]
The output signals of the color difference amplifying circuits 46 a to 46 c and 46 a ′ to 46 c ′ and the luminance signal Y are input to the enhancement circuit 47, the contours are emphasized, and then output through the D / A conversion circuit 48.
[0054]
The color difference signals RY and BY read from the frame memories 44b and 44c are input to the automatic selection circuit 49, the distribution state of the color difference signals RY and BY is determined, and the changeover switch SW. The switching of the change-over switches 45a and 45b is controlled through the contact a. The output signal of the image adjustment input unit 22 is applied to the contact b of the changeover switch SW.
The input switching circuit 50 can select between automatic selection and manual selection.
[0055]
  Next, the operation of this embodiment will be described.
  Even if the color that changes from the center to the periphery of the screen is a color, the same operation as in the first embodiment can be obtained.
  In the case of an endoscope equipped with a color solid-state image sensor, the color characteristics change at the center and periphery of the solid-state image sensor depending on the incident characteristics of the combined lenses, and color shading called color shading occurs. The color difference signal amplification levelChangeCorrection can be performed by gradually changing from the center of the screen to a concentric shape. If correction can be made by this image adjustment, it is not necessary to deal with the solid-state image pickup device side in the conventional example, such as making it appropriate by pasting complicated filters, and correction can be made easily.
[0056]
The present embodiment has the following effects.
It is not necessary to deal with conventional solid-state imaging devices such as color unevenness, which is advantageous in terms of yield of solid-state imaging devices, and is advantageous in terms of total cost merit.
[0057]
It should be noted that a circuit for correcting the color shading (color unevenness) shown in FIG. 7 is provided in place of the color correction circuit 36 in the image adjustment circuit 21 shown in FIG. You may enable it to perform both correction | amendment of color nonuniformity.
[0058]
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. The purpose of this embodiment is to reduce the size of a zoom imaging apparatus. For this reason, in this zoom imaging apparatus, a lens driving means is provided in front of a horizontally-mounted solid-state imaging apparatus having a prism. In this case, the lens driving means is housed within the prism projection area.
FIG. 8 shows a configuration of the distal end portion 52 of the electronic endoscope 51 according to the present embodiment, and a zoom imaging device 53 is provided at the distal end portion 52.
[0059]
The tip portion of the light guide 55 is fixed to the illumination window of the tip member 54 constituting the tip portion 52, and the illumination lens 56 is fixed facing the tip surface. A zoom imaging device 53 is attached to an observation window provided adjacent to the illumination window.
This zoom image pickup device 53 includes a drive lens 57, a zoom objective lens 58 fixed to a lens frame 59, a prism 60, and a longitudinal direction of an endoscope 51 fixed to the rear surface (exit-side surface) of the prism 60. The solid-state imaging device 61 is arranged in a so-called lateral direction with the imaging surfaces arranged in parallel to each other, a circuit board 62, a signal transmission cable 63, and an actuator 64 for driving the driving lens 57.
[0060]
The actuator 64 is installed in the projection area including the prism 60, the solid-state image sensor 61, and the circuit board 62 in front of the solid-state image sensor 61, and is housed inside the tip member 54. FIG. 9 of the AA cross section of FIG. 8 shows the actuator 64 and the drive lens 57 driven thereby.
An electronic component 65 is mounted on the circuit board 62, and its periphery is sealed with a sealant 66.
[0061]
The drive line of the actuator 64 is connected to the signal transmission cable 63 for the solid-state image sensor via the circuit board 62. Other configurations are the same as those in the first or second embodiment.
[0062]
The present embodiment has the following effects.
The space for the actuator 64 alone is not required, the zoom imaging device 53 can be reduced in size, and the tip 52 can be reduced in diameter. The other effects are the same as those of the first or second embodiment.
[0063]
(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. 10A shows a zoom imaging apparatus, FIG. 10B shows an exploded view of a liquid crystal lens and optical elements on both sides thereof, and FIG. 10C shows the state in which FIG. 10B is integrated. An electrode and the like when viewed from above are shown.
The purpose of this embodiment is to reduce the size of a zoom imaging apparatus. For this reason, in this zoom imaging apparatus, a liquid crystal lens is provided between the prism and its front lens. The liquid crystal lens and the prism are integrated.
[0064]
The zoom imaging apparatus 53 ′ according to the present embodiment is the same as the zoom imaging apparatus 53 according to the third embodiment except that a liquid crystal lens is interposed between the prism 58 and the lens 58a to which the front surface (incident side surface) of the prism 60 is fixed. 71 was provided.
The liquid crystal lens 71 is a biconcave lens, and has transparent electrodes 72 on both sides (see FIG. 10B). The rear side of the lens 58a is a flat surface, and a transparent electrode 73 is also provided here. The front surface of the prism 60 on the liquid crystal lens side is also a flat surface, and a transparent electrode 74 is also provided here.
[0065]
The liquid crystal lens 712 is sandwiched between the lens 58a and the prism 60 from both sides like a sandwich, and the internal space between them is filled with liquid crystal. As shown in FIG. 10C, electrodes a to d are extended to the outside for application of voltage from each transparent electrode, and are connected to a flexible substrate 75 and connected to an external power source via a signal transmission cable 63. Can be driven. Other configurations are the same as those in the first or second embodiment.
[0066]
The present embodiment has the following effects.
Since the liquid crystal lens 71 is used, the refractive index of the liquid crystal can be changed arbitrarily by changing the liquid crystal state according to the driving state from the outside, so that a so-called lens effect can be achieved, and the number of lenses can be reduced. The lens can be made small. Further, since the prism 60 and the liquid crystal lens 71 are integrated, handling during assembly is facilitated.
[0067]
[Appendix]
1. An endoscope having at least an imaging means and an illumination means;
Video signal converting means for visualizing a signal from the imaging means;
In an endoscope system having a display device for displaying a video signal,
An endoscope system having an image adjusting unit that enables adjustment of an image characteristic that changes from the center of a display area of a display area displayed on a display device toward the periphery thereof from the center of the display area to the periphery.
[0068]
2. Illumination means and means for changing the brightness state changing from the center of the display area of the subject imaged on the display device determined by the state of the subject from the center to the periphery in a concentric manner with the center of the display area as a substantially center. The endoscope system according to appendix 1, wherein the image adjustment means is used.
3. The endoscope system according to appendix 1, wherein at least a video signal level of either a luminance level or a color signal can be adjusted.
4). The endoscope system according to supplementary note 1, wherein an adjustment level of the image adjusting unit can be arbitrarily adjusted.
[0069]
5. An endoscope having at least an imaging means and an illumination means;
Video signal converting means for visualizing a signal from the imaging means;
In an endoscope system having a display device for displaying a video signal,
An image characteristic that changes from the center to the periphery of the display area of the endoscopic image displayed on the display device is adjusted so that the illumination characteristic of the illuminating means is flattened from approximately the center to the periphery of the display area. An endoscope system having an image adjusting means that enables the endoscope system.
[0070]
【The invention's effect】
  As described above, according to the present invention,By making it possible to adjust the image of the subject that changes from the center to the periphery of the screen, it is possible to obtain a good image over the entire image display area, and to capture the same part under the same conditions in different states in time It is possible to provide an endoscope system suitable for the purpose.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an endoscope system according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of an image adjustment unit.
FIG. 3 is a diagram showing amplification characteristics of an amplifier circuit.
FIG. 4 is a diagram illustrating a representative position on a display surface of a monitor and a solid-state imaging device in which pixels for detecting a luminance distribution are set correspondingly.
FIG. 5 is an explanatory diagram of an action when a flat subject is imaged.
FIG. 6 is an explanatory diagram of an action when a luminal subject is imaged.
FIG. 7 is a block diagram showing a configuration of an image adjustment circuit according to a second embodiment of the present invention.
FIG. 8 is a cross-sectional view showing a structure of a tip portion according to a third embodiment of the present invention.
9 is a cross-sectional view taken along line AA in FIG.
FIG. 10 is a diagram illustrating a zoom imaging apparatus and the like according to a fourth embodiment of the present invention.
[Explanation of symbols]
1. Endoscope system
2 ... Electronic endoscope
3. Light source device
4 ... CCU
5. Image adjustment unit
6 ... Monitor
7 ... Insertion section
8. Light guide
10 ... tip
11. Illumination optical system
12 ... Subject
13 ... Objective optical system
14 ... Solid-state imaging device
15 ... Imaging device
17 ... Drive circuit
18: Preprocess circuit
19 ... Amplifier
20 ... CDS circuit
21. Image adjustment circuit
22. Image adjustment input unit
23 ... Post-process circuit
31 ... A / D conversion circuit
32 ... Frame memory
33 ... changeover switch
34A to 34E ... Amplifier circuits A to E
35 ... Enhanced circuit
36. Color correction circuit
37 ... D / A conversion circuit
38 ... Automatic selection circuit
39 ... Auto / manual switch
40. Input switching circuit

Claims (3)

An endoscope having a IMAGING unit and an illumination unit,
A video signal means for generating a video signal for imaging signals from the imaging means, and outputs to the display device,
In an endoscope system having
And adjustable from the center toward the periphery of the display device around the display image characteristic changes toward the periphery from the display area of the endoscopic image as an image of the object corresponding to the image signal that appears on Image adjusting means comprising a plurality of amplifier circuits having different amplification characteristics ;
Selection means for selecting an amplification circuit to be used for amplification of the video signal from the plurality of amplification circuits;
Image recording means for recording the information of the amplifier circuit actually selected and used in the image adjustment means together with the endoscopic image,
Using the information recorded in the image recording means, in the next endoscopy, when imaging the same part as the previous time when the information was recorded, it was possible to select and use the same amplification circuit as the previous time An endoscope system characterized by that. Illumination means and means for changing the brightness state changing from the center of the display area of the subject imaged on the display device determined by the state of the subject from the center to the periphery in a concentric manner with the center of the display area as a substantial center The endoscope system according to claim 1, wherein the image adjustment unit is used. The endoscope system according to claim 1 , wherein the image adjusting unit is capable of adjusting at least a video signal level of either a luminance level or a color signal.

Images