JP2874305B2 - Electronic endoscope device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic endoscope apparatus used for medical use or the like.

[Prior Art] In an electronic endoscope, a solid-state imaging device made of a CCD or the like is provided at the tip of an insertion portion to be inserted into a human body or the like, and a part to be observed is photographed by the solid-state imaging device. This allows the image to be displayed as a color image on a monitor device.

Here, since this endoscope is inserted into a dark place such as the inside of the body, it is necessary to illuminate the site when performing observation, diagnosis, and the like. For this purpose, the endoscope is connected to a light source device, and illumination light from a light source lamp provided in the light source device is transmitted to a distal end portion of the insertion portion via a light guide built in the endoscope. Then, illumination light is emitted from an illumination window provided at the distal end of the insertion portion.

Thus, under illumination from the light source device, an image of the observation target portion is formed on the solid-state imaging device to accumulate signal charges in each pixel constituting the solid-state imaging device, and the signal charges are read out. As an imaging method using this solid-state imaging device, since it is necessary to reduce the diameter of the insertion portion of the endoscope,
Usually, a single-plate element is used. Further, in order to improve the resolution of the image, the solid-state imaging device is driven by a plane sequential method to obtain a field image of each color of red (R), green (G), and blue (B), and obtain a field image of each of these colors. In general, a field image is transmitted to a video signal processing apparatus, and these three field images are mixed to form a composite video signal, and a color video is generally displayed based on this signal.

Here, the light source device and the video signal processing device can be configured as independent devices, but in many cases, a single control device is provided, and the control device incorporates the light source device and the video signal processing device.

The illumination light emitted from the light source lamp via the light guide must selectively emit the wavelength region light of each color of R, G, and B. Further, in order to read out the signal charges stored in the solid-state imaging device, it is necessary to provide a light-shielding period between the illumination periods by the wavelength region light of each color. Therefore, a rotating color filter device is interposed in the optical path of the illumination light from the light source lamp to the entrance end of the light guide.

This rotary color filter device has an R filter region that transmits red wavelength region light, and a G filter region that transmits green wavelength region light.
A color wheel having a filter track composed of a filter area and a B filter area that transmits light in the blue wavelength region, a light shielding area provided between these filter areas, a motor for rotating and driving the color wheel, and the like. And driving means.

Therefore, when the color wheel is rotationally driven, the R filter area, the light shielding area, the G filter area, the light shielding area, the B filter area, and the light shielding area come to the illumination light path in this order. As a result, in the red light irradiation period in which the R filter region faces the illumination light path, the image signal in the R field is accumulated in the solid-state imaging device, and the signal is read out during the light shielding period. Next, the image signal of the G field is accumulated during the green light irradiation period in which the G filter region faces the illumination light path, and the signal charges are read out during the light shielding period. Further, when the B filter area faces the illumination light path and a blue irradiation period is started, an image signal of the B field is accumulated in the solid-state imaging device, and this signal charge is read out during the light shielding period. This operation is sequentially repeated so that a video signal at the observation target portion is obtained.

In addition, the circuit configuration and the like of a video signal processing device that reads an image signal from a solid-state imaging device and generates a video signal also have different configurations depending on the type of the solid-state imaging device.

[Problems to be Solved by the Invention] By the way, in recent years, various types of solid-state imaging devices have been developed and put into practical use.
The types of elements that can be mounted on endoscopes are also increasing. The video signal processing device has a different circuit configuration based on the type of the solid-state imaging device. In addition, these solid-state imaging devices have different sensitivities to the wavelengths of R, G, and B colors depending on their types and characteristics. Therefore, in order to maintain good image quality, it is necessary to adjust the illumination period of each wavelength light according to the sensitivity characteristics of the solid-state imaging device. In addition, it is necessary to change the charge accumulation time, the accumulated charge reading time, and the like depending on the solid-state imaging device.

However, the above-mentioned conventional electronic endoscope apparatus cannot be used in common for endoscopes having solid-state imaging devices of different types and characteristics, and when performing special examinations and diagnoses. However, there is an inconvenience and inconvenience that a dedicated light source device must be used.

The present invention has been made in view of the above points, and an object of the present invention is to provide a light source mechanism and a video signal processing in which a built-in solid-state imaging device can be used for a plurality of types of electronic endoscopes different from each other. It is to provide an electronic endoscope device provided with a mechanism.

[Means for Solving the Problems] In order to achieve the above-described object, the present invention provides an endoscope having a solid-state imaging device driven by a frame sequential method, in which a light source connector of a universal cord of an endoscope is detachably connected. Light source mechanism, and an image signal processing mechanism to which an electrical connector is detachably connected. The light source mechanism sequentially transmits wavelengths of R, G, and B in the optical path of illumination light from a light source lamp. A filter wheel, a plurality of types of color wheels formed concentrically so that the irradiation time of each illumination light is different, and a driving means for rotating the color wheel,
A rotating color filter device having wheel displacement means for switching any of these filter tracks so as to face the optical path is provided, and a video signal processing mechanism is provided with a plurality of types of video signal processing means,
In each of these video signal processing means, at least a memory for recording image data and a color encoder are shared, and a certain type of solid-state image pickup device among solid-state image pickup devices driven in each plane-sequential system is provided. When the endoscope is connected to the light source mechanism and the video signal processing mechanism, the type of the endoscope is detected, and video signal processing means suitable for the solid-state imaging device is selected. It is characterized in that it comprises a selecting means for displacing the filter track so as to face the optical path.

[Operation] In order to connect a plurality of endoscopes having different types of solid-state imaging devices, a rotating color filter device capable of selecting a filter track is provided with a light source mechanism, and a plurality of types of video signal processing means are connected to a video signal processing device. Provided in the signal processing mechanism. When a predetermined type of endoscope is connected, video signal processing means suitable for the solid-state imaging device is selected, and the color wheel of the rotating color filter is displaced, so that the predetermined filter track is moved to the illumination optical path. Will face. In this state, a video signal is acquired by the solid-state imaging device, so that a clear image with excellent color balance and the like and extremely high image quality can be obtained.

For example, in recent years, solid-state imaging devices with extremely high sensitivity that can store signal charges at twice the speed of conventional ones have been developed, and electronic endoscopes having conventional solid-state imaging devices have been developed. In the case where an electronic endoscope having a high-sensitivity solid-state imaging device can be connected, video signal processing means suitable for each of them is provided in the video signal processing mechanism, and in the rotating color filter device, a color wheel A filter track in which each of the R, G, and B filter areas is formed at one location in one rotation, and a filter track in which each of the filter areas is provided at two locations are formed concentrically.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 shows an internal configuration of a light source device including a rotary color filter device, FIG. 2 shows a rotary color filter device, FIG. 3 shows a color wheel, and FIG. 4 shows an electronic endoscope device. Are respectively shown.

As is apparent from FIG. 4, the endoscope apparatus is generally constituted by an endoscope S, a control device C, and a monitor device M. The endoscope S includes an insertion portion 1 inserted into a body cavity or the like, a main body operation portion 2 provided continuously to a base end of the insertion portion 1, one end of which is connected to the main body operation portion 2, and the other end. And a universal cord 3 detachably connected to the control device C. The control device C includes a video signal processing mechanism P and a light source mechanism L.

An illumination window and an observation window are provided at a distal end portion of the insertion section 1 in the endoscope S, an emission end of a light guide for transmitting illumination light faces the illumination window, and an objective lens provided in the observation window is provided. A solid-state image pickup device such as a CCD is mounted at the image forming position. However, since these components are well known, their illustration and specific description are omitted.

Thus, the cable connected to the light guide and the solid-state imaging device is inserted from the insertion section 1 of the endoscope S through the main body operation section 2 to the universal cord 3. It is branched into an electric connector 3a for detachably connecting to the video signal processing mechanism P in the control device C and a light source connector 3b for connecting the light guide to the light source mechanism L of the control device C. On the control device C side, a socket 4a for connecting the electric connector 3a and a socket 4b for connecting the light source connector 3b are provided.

Next, as is apparent from FIG. 1, the light source mechanism L incorporated in the control device C has a light source lamp 10, and in order to collect illumination light from the light source lamp 10 to the light guide 11, The condenser lens 12 is provided so as to face the optical path of the illumination light. In order to control the light amount of the light source according to the position of the observation target portion, a light amount diaphragm member 13 is interposed between the light source amplifier 10 and the condenser lens 12. Further, a rotary color filter device 20 is mounted at a position between the condenser lens 12 and the incident end 11a of the light guide 11.

As shown in FIG. 2, the rotary color filter device 20 filters the white light emitted from the light source lamp 10 and makes the white light enter the light guide 11. As shown in FIG. Further, a color wheel 21 having a filter track formed by forming a plurality of filter areas in an arc shape is provided, and the color wheel 21 is mounted on a rotating shaft 22.
A pulley 23 is connected to the rotating shaft 22.
A transmission belt 26 is wound and provided between the pulley 23 and the pulley 25 mounted on the output shaft 24a of the motor 24. Therefore, by operating the motor 24 and rotating the color wheel 21, a plurality of filter areas formed in the filter track are sequentially made to face the optical path of the illumination light.

Here, the light source mechanism L is configured to be able to emit two different illumination lights in order to be able to perform photographing with two types of solid-state imaging devices. For this purpose, the color wheel 21
One filter track 27, 28 is formed. The outer filter track 27 includes filter regions 27R, 27G, and 27B that selectively transmit light of each wavelength of R, G, and B, and filter regions 27R and 27R.
G, between filter areas 27G and 27B and filter area 27B.
And 27R. Then, in order to selectively transmit light of each wavelength of R, G, and B, the filter regions 28R1, 2
8G1, 28B1 and filter areas 28R2, 28G2, 28B2 are formed, and these filter areas are formed so as to sandwich the light shielding area 28BL.

In order to switch the filter tracks 27 and 28, wheel displacement means is provided. The wheel displacing means includes a color wheel 21, an elevating support member 29 on which a motor 24 for driving the color wheel 21 and a pulley 23 are mounted, and the elevating support member 29 is attached to a guide rod 30. It can be moved up and down along the axis, and is connected to a pulse motor 31 for driving up and down via an eccentric gear 32. Accordingly, when the pulse motor 31 is operated, the elevating and lowering support member 29 is moved up and down, the color wheel 21 is displaced in the vertical direction, and the filter track 27 faces the illumination light path, and the filter track 28 is moved to the illumination light path. It is possible to switch between the states facing the.

Then, when the filter track 27 faces the optical path of the illumination light from the light source lamp 10 to the light guide 11, as shown in FIG. 5 (a), the illumination by the R, G, B illumination light Irradiation occurs every 16.6 ms. When the filter track 28 faces the optical path of the illumination light, it corresponds to each of the illumination periods described above, as shown in FIG.
Each illumination light of R, G, and B is sequentially irradiated twice in 16.6 ms.

By the way, the solid-state imaging device mounted on the endoscope is not always fixed.

At present, as a solid-state imaging device used for an endoscope, for example, a solid-state imaging device having a light receiving area having a predetermined number of pixels is used. In the case of imaging with this element, it is necessary to expose this solid-state imaging element for about 16.6 ms to obtain one color data. However, in recent years, the sensitivity characteristics of the solid-state imaging device have been improved, and a device capable of acquiring necessary color data in approximately half the exposure time of the device has been developed. As described above, when a high-sensitivity element is used, the same resolution as that of the above-described element can be obtained even if the number of pixels in the image area is reduced. Therefore, even an element having about half the number of pixels in the vertical direction as a light receiving area can obtain an image of a practically acceptable level. The fact that the number of pixels can be reduced in this way allows the solid-state imaging device to be downsized,
The diameter of the insertion portion of the endoscope can be reduced, which is extremely convenient.

Therefore, when a CCD 40 having a normal number of pixels in the light receiving area is used as the solid-state imaging device, as shown in FIG. 5 (a), the illumination light by the wavelength region light of each color of R, G, and B is used. 1
Irradiation is performed every 6.6 ms, during which the CCD 40 is exposed. To process the image signal acquired by the CCD 40 in this manner, the video signal processing mechanism P in the control device C is configured as shown in FIG.

Thus, the signal charges stored in the CCD 40 are transmitted to the video processor 41 to perform predetermined signal processing such as signal clamping and adjustment of R, G, and B gains. As a result, as shown in FIG. 5 (b), the video signal of each color of R, G, B is sequentially output from the video processor 41. Then, this output signal is converted into a digital signal by the A / D converter 42, and is sequentially written into the R memory area 43R, the G memory area 43G, and the B memory area 43B in the memory 43. When the color data of each color for the frame is written, the D / A converters 44R, 44
These data are read out simultaneously via G, 44B,
The signals are mixed in the color encoder 45 and output as a composite video signal such as NTSC.

Here, the reading of the signal to the color encoder 45 is performed as follows.
In actuality, as is clear from FIG. 5 (c), only the image data of one of R, G, and B colors is updated for the previous field, and the data of the other colors is The same will be read. The composite video signal output from the color encoder 45 includes an odd field (O) signal and an even field (E) signal as shown in FIG. 5 (d).

On the other hand, when a small and highly sensitive CCD 50 having approximately half the number of pixels in the vertical direction is used as the light receiving area, signal processing is performed in a different method from that of the CCD 40. That is,
The video signal processing apparatus using the high-sensitivity CCD 50 is configured as shown in FIG.

That is, as shown in FIG. 6 (a), the rotation color filter device 20 outputs R, G, and B of each of R, G, and B with a half irradiation period as compared with that shown in FIG. 5 (a). Illumination light of each color wavelength is sequentially irradiated twice. This allows for high sensitivity
The signal output from the CCD 50 via the video processor 51 is, as shown in FIG. 6B, image data of each color of R, G, B within a period corresponding to one field of the CCD 40 described above. Means that the imaging color data of the odd field and the imaging color data of the even field are sequentially obtained. Therefore, each of these color data is converted into a digital signal by the A / D converter 52, and the memory 53 has an odd memory area 53R0, 53G in each of the R, G, B memory areas 53R, 53G, 53B.
0,53B0 and even memory area 53RE, 53GE, 53GE (In practice, the odd memory area and the even memory area are performed by processing on the address in the memory area, and the memory area is not divided into two. Not). In addition,
Rewriting of the color data in each of the memory areas 53R, 53G, 53B is performed one field at a time for one frame, as in the case of using the CCD 40.

However, when the color data thus written to the memory 53 is read out to the color encoder 55 via the D / A converters 54R, 54G, 54B, the color data is read from the odd memory area and the even memory area in each memory area. Data is read alternately for each line. This allows the color encoder 55
As shown in FIG. 6 (c), the image data of each color is simultaneously read from the D / A converters 54R, 54G and 54B, respectively, and by these, the data shown in FIG. like,
A composite video signal consisting of odd and even fields is obtained.

Therefore, an endoscope S 'with a built-in CCD40 and a high-sensitivity CCD50
When the control device C is shared with the endoscope S ″ using
First, it is necessary to share a circuit of a video signal processing means including a video processor and a memory for processing video data obtained by these two types of different CCDs 40 and 50. For this purpose, the video signal processing mechanism P is configured as shown in FIG.

In other words, CCD40 or 5
A video processor that processes output signals from 0 must use different ones depending on the type of solid-state imaging device. Therefore, a video processor 60a constituting the video signal processing means for the CCD 40 and a video processor 60b constituting the video signal processing means for the high-sensitivity CCD 50 are provided, and these video processors 60a and 60b can be switched by the input switch 61. And

An output switch 62 is provided at an output stage of each of the video processors 60a and 60b, and data from the video processor 60a or 60b is output through the output switch 62 via the A / D converter 63, and stored in the memory. The data is written to the respective memory areas 64R, 64G, 64B of R, G, B in 64. The data written in each of the memory areas 64R, 64G, 64B in the memory 64 is simultaneously read out via the D / A converters 65R, 65G, 65B, and a composite video signal is obtained by the color encoder 66.

Thus, the video processor as the imaging system must use different circuit configurations as the video signal processing means including the video processor and the memory, depending on the type of the solid-state imaging device. In the system, the read control from the memory 64 is different for the CCD 40 and the high-sensitivity CCD 50, but the A / D converter 63, the memory 64 for recording image data, the D / A converters 65R, 65G, 65B and the color The circuit configuration itself including the encoder 66 can be shared. Further, a master clock circuit 67 for generating a clock pulse for controlling the entire video signal processing mechanism can be shared.

Furthermore, in the imaging system, dedicated video processors 60a, 60b are used, and the video processors 60a, 60b are used.
When writing output signals from the memory 64 to the memory 64, it is necessary to use different clock pulses, so the control means 68 must be able to switch between the control signal for the CCD 40 and the control signal for the CCD 50. No. Also, in the display control means 69 for reading a signal from the memory 64 and obtaining a composite signal, the control signal at the time of reading from the memory 64 is used for controlling the CCD 40 and the CCD 50.
It must be different from that for control.

The CCD drive circuit 70 is also configured to generate two types of clock pulses based on the clock signal from the master clock circuit 67. That is, the control means 6
8, 69 and the CCD drive circuit 70 are the drive mode for the CCD 40 and the CCD 5
The drive mode for 0 is selectively switched.

Here, the endoscope S 'equipped with the CCD 40 or the high-sensitivity CCD
When any one of the endoscopes S ″ equipped with 50 is connected to the control device C, the type of the endoscope is automatically detected,
ID (Identification) as a selection means to select
A mechanism is provided. This ID mechanism includes an ID determining member such as an ID determining pin provided on the electrical connector 3a of the universal cord 3 in the endoscope, and an ID decoder 71 on the control device C side. When the type of mirror is detected, this ID detection signal is input to each control means 68 and 69 in the imaging system and display system, and a switching control signal is input to the solid-state imaging device driving circuit 70, and the driving mode for the CCD 40 and the driving mode for the CCD 50 are input. The mode can be switched to the drive mode.

In addition, when the CCD 40 is used and when the high-sensitivity CCD 50 is used, the illumination system includes the illumination shown in FIG. 5 (a) and the illumination shown in FIG. 6 (a). To
The lighting style must be changed. For this purpose, the ID detection signal from the ID decoder 71 is taken into the color filter device 20, and the pulse motor 31 is driven to raise and lower the elevating support member 29 so that the color wheel 21 is orthogonal to the optical axis of the illumination optical path. In such a direction as to be displaceable.

Therefore, when the endoscope S 'having the CCD 40 is connected to the control device C, this is detected by the ID decoder 71, and the control means is controlled based on the signal from the ID decoder 71.
The 68, 69 and CCD drive circuits 70 enter the drive mode for the CCD 40, and the color wheel 21 is displaced in a direction orthogonal to the illumination light path, so that the filter track 27 faces this illumination light path. Thereby, illumination is performed in the manner shown in FIG. 5 (a).

On the other hand, the endoscope S ″ having the high sensitivity CCD 50 is
When the ID decoder 71 detects this, the control means 68, 69 and the CCD drive circuit 70 are switched to the drive mode for the high-sensitivity CCD 50, and the pulse motor 31 is operated,
The color wheel 21 is switched to a state where the filter track 28 faces the illumination light path, and as shown in FIG. 6 (a), while the color wheel 21 makes one rotation, each wavelength of R, G, B Illumination by light is repeated twice.

By moving the color wheel 21 in this manner, members such as the light source lamp 10, the condenser lens 12, and the light amount stop member 13 can be shared, and two types of endoscopes S 'and S "can be used. The overall configuration of the light source mechanism L in the control device C to which can be connected can be extremely reduced in size and size.

In the above-described embodiment, the CCD 40 and the high-sensitivity CCD are used.
Although shown as a rotary color filter device that can be shared with 50, even if the type is the same, the characteristics of the solid-state imaging device due to differences in manufacturers, for example, R, G, B sensitivity characteristics, If it is necessary to finely change the filter tracks formed on the color wheel in order to obtain good images due to differences in charge transfer timing, etc., filter tracks according to the characteristics of each solid-state image sensor etc. It may be formed in two or more concentric circles. Further, as the wheel displacement means, the one configured to drive the lifting support member up and down by the pulse motor and the eccentric gear has been described, but other than this, for example, a ball screw drive mechanism or the like may be used.

[Effects of the Invention] Since the present invention is configured as described below, a light source mechanism is shared with a plurality of types of electronic endoscopes including a solid-state imaging device driven by a plane sequential method, and a video signal is Among the processing mechanisms, many circuit components including the memory for recording image data and the color encoder can be shared, and the electronic endoscope device as a whole can be made versatile with a small and compact configuration. When the electronic endoscope is connected to the light source mechanism and the video signal processing mechanism, the solid-state imaging device provided in the electronic endoscope is identified, and a filter track and a video signal processing means suitable for the solid-state imaging device are automatically determined. In addition, the color wheel is provided with a plurality of filter tracks having different illumination times of R, G, and B in accordance with the characteristics of each solid-state imaging device and the like, and corresponds to the type of solid-state imaging device. Since the filter track is selected with the video obtained by the various solid-state image pickup device becomes extremely sharp, the effect of such to improve the accuracy of endoscopy.

[Brief description of the drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an internal configuration diagram of a light source device including a rotating color filter device,
FIG. 2 is an explanatory view of a configuration of a rotary color filter device, FIG. 3 is a front view of a color wheel, FIG. 4 is an explanatory view of an overall configuration of an endoscope device, and FIG. 5 (a) is illumination by one filter track. FIG. 4B shows the light irradiation period, FIG. 4C shows the output signal of the video processor at that time, FIG. 4C shows the output signal from the memory, and FIG. 5D shows the output signal of the color encoder. FIG. 6 (a) shows the illumination light irradiation period by another filter track, FIG. 6 (b) shows the output signal of the video processor at that time, and FIG. 6 (c) shows the output signal from the memory. FIG. 7 (d) is a characteristic diagram showing output signals of the color encoder, FIG. 7 is a circuit configuration diagram of one video signal processing device, FIG. 8 is a circuit configuration diagram of another video signal processing device, FIG. Is a video signal processing device with two video signal processing functions It is a circuit diagram of a. 1: Insertion section, 2: Main body operation section, 3: Universal cord, 3a:
Electrical connector part, 3b: light source connector part, 10: light source lamp,
11: light guide, 20: rotating color filter device, 21: color wheel, 22: rotating shaft, 23: pulley, 24: motor, 26:
Transmission belt, 27: filter track, 27R, 27G, 27B: filter area, 27BL: light shielding area, 28: filter track, 28R1, 28R
2,28G1,28G2,28B1,28B2: Filter area, 28BL: Shade area, 29:
Elevating support member, 30: guide rod, 31: pulse motor, 3
2: Eccentric gear.

Continuation of front page (56) References JP-A-2-29612 (JP, A) JP-A-63-274910 (JP, A) JP-A-1-128314 (JP, U) (58) Fields studied (Int .Cl. ⁶ , DB name) G02B 23/00

Claims (1)

(57) [Claims] 1. A light source mechanism in which a light source connector of a universal cord of an endoscope having a solid-state imaging device driven in a frame sequential manner is detachably connected, and a video signal processing in which an electric connector is detachably connected. The light source mechanism further includes a filter track that sequentially transmits the wavelengths of R, G, and B in the optical path of the illumination light from the light source lamp so that the illumination time of each illumination light is different. A plurality of types of concentrically formed color wheels, a driving means for rotating and driving the color wheels, and a wheel displacement means for switching any one of the filter tracks so as to face the optical path. A color filter device is provided, and the video signal processing mechanism is provided with a plurality of types of video signal processing means. The endoscope provided with a certain type of solid-state imaging device among the solid-state imaging devices driven by each of the above-described plane-sequential systems also has a light source mechanism and a video signal. When connected to the processing mechanism, the type of the endoscope is detected, video signal processing means suitable for the solid-state imaging device is selected, and a filter track suitable for the solid-state imaging device faces the optical path. An electronic endoscope apparatus comprising a selecting means for displacing.