JPH05207973A - Electronic endoscope system - Google Patents

Abstract

PURPOSE:To obtain the electronic endoscope system which can easily increase the sensitivity. CONSTITUTION:A video signal read out of a solid-state image pickup element 16 is inputted to a pre-amplifier 32 through a signal line 27, and the video signal amplified by this pre-amplifier 32 is inputted to a process circuit 33, subjected to signal processing such as a gamma correction and white balance, etc., and converted to a signal by an A/D converter 34. An output video signal of the A/D converter 34 is selectively stored in memories 36a, 36b and 36c, synchronized by a memory controller 60, converted to an analog signal by a D/A converter 37, subjected to prescribed processing and outputted. On the other hand, a timing generator 42 and the memory controller 60 are connected to a mode changeover switch 61, and in accordance with an instruction of the mode changeover switch, an operation mode is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope in which an object image from a solid-state image pickup device is divided into information of odd fields and information of even fields by interlaced scanning and alternately read and stored.

[0002]

2. Description of the Related Art In recent years, it has been possible to observe an organ in a body cavity by inserting an elongated insertion portion into the body cavity and to perform various medical treatments by using a treatment instrument inserted in a treatment instrument channel as needed. Endoscopes are widely used. Further, a charge-coupled device (hereinafter, CCD
Abbreviated. ) Or the like, and various types of electronic endoscopes have been proposed in which a solid-state image sensor is provided and image information is extracted as a photoelectrically converted electric signal.

A conventional example will be described below with reference to the drawings.

9 and 10 relate to a conventional example, and FIG. 9 is a block diagram showing a configuration of a main part of an electronic endoscope apparatus, FIG.
Reference numeral 0 is an explanatory diagram illustrating a method of reading from the solid-state image sensor.

In the conventional electronic endoscope apparatus, as shown in FIG. 9, a light guide 14 for transmitting illumination light is inserted into the insertion portion 2 of the electronic endoscope 1. The tip end surface of the light guide 14 is arranged at the tip end portion 9 of the insertion portion 2, and the illumination light can be emitted from the tip end portion 9.
Further, the incident end side of the light guide 14 is connected to a video processor 6 having a light source device and a signal processing circuit built therein. An objective lens system 15 is provided at the tip portion 9, and a solid-state image sensor 16 is provided at the image forming position of the objective lens system 15. The solid-state image sensor 16 has sensitivity in a wide wavelength range from the ultraviolet region to the infrared region including the visible region. Signal lines 26 and 27 are connected to the solid-state image sensor 16.

On the other hand, in the video processor 6, there is provided a lamp 21 which emits light in a wide band from ultraviolet light to infrared light. As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used.
The xenon lamp and strobe lamp emit a large amount of ultraviolet light and infrared light as well as visible light. This lamp 2
1, the power source 22 supplies electric power. A rotary filter 50, which is rotationally driven by a motor 23, is arranged in front of the lamp 21.
Filters that transmit light in the respective wavelength regions of red (R), green (G), and blue (B) for normal observation are arranged in the rotary filter 50 along the circumferential direction.

The motor 23 is controlled in rotation by a motor driver 25 and driven.

After passing through the rotary filter 50, R, G,
The light that is time-sequentially separated into the lights of the respective wavelength regions of B is further incident on the incident end of the light guide 14, is guided to the tip portion 9 through the light guide 14, and from the tip portion 9. The light is emitted to illuminate the observation site.

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

In the video processor 6, a timing generator 42 for generating the timing of the entire system is provided, and the timing generator 42 synchronizes the circuits of the motor driver 25 and the driver circuit 31. ..

In this frame-sequential imaging system, Japanese Patent Laid-Open No.
For example, Japanese Patent Laid-Open No. 152437/1982 proposes a method of reading out both an odd field and an even field in one field in order to improve the vertical resolution.

A reading and synchronizing method of this system is shown in FIG.
Shown in.

The video signal is sent from the solid-state image pickup device 16 to FIG.
130, RO1 → RE1 → BO1 → BE1 → GO1
→ Read in the order of GE1. The symbol O on this color signal corresponds to the information in the odd field, and E corresponds to the information in the even field. As shown in the figure, 1 information is 1/120
Reading in seconds, odd field information and even field information can be obtained in one field period (1/60 seconds). The read video signals are synchronized by the frame memory as shown at 132 in FIG. This is because since odd-numbered field information and even-numbered field information are obtained as 1-frame information in a 1/30 second period, an image with high vertical resolution and less color shift can be obtained.

[0014]

However, when the reading method in FIG. 9 of the conventional example is performed, as described above, 1
The field exposure period is 1/120 second, so
The above-described read-out method alone has a drawback in that sensitivity is disadvantageous when driving the electronic endoscope.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an electronic endoscope apparatus whose sensitivity can be easily increased.

[0016]

An electronic endoscope apparatus according to the present invention
Is time-sequentially by multiple illumination lights with different wavelength ranges.
The illuminating means for illuminating and the illuminating light from this illuminating means
A solid-state image sensor that captures an image of a subject illuminated by
Reads from the solid-state image sensor and supports the multiple illumination lights
Multiple memory hands that store the image pickup signals obtained by
And the image output based on the output from the plurality of storage means.
And an electronic endoscope device including a generating unit that generates a signal.
Read control for controlling the read of the solid-state image sensor.
Control means and controlling writing to the plurality of storage means
Write control means, the read control means and the write
Operation cycle control means for controlling the operation cycle of the biting control means
And an instruction hand for instructing the control content of the operation cycle control means.
Equipped with steps.

[0017]

[Operation] The operation cycle control means controls the operation cycles of the read control means and the write control means based on the control content instructed by the instruction means.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 relate to a first embodiment of the present invention. FIG. 1 is a block diagram showing the overall structure of an electronic endoscope apparatus, and FIG. 2 is a structure of a main part of the electronic endoscope apparatus. FIG. 3 is a block diagram showing the same, FIG. 3 is an explanatory view for explaining a reading method of the solid-state image pickup device, and FIG. 4 is an explanatory view for explaining read-out timing of the interlaced read-out solid-state image pickup device when sensitivity is increased and synchronized output signals. FIG. 5 is an explanatory diagram for explaining the read timing of the non-interlaced read solid-state image sensor when the sensitivity is increased and the synchronized output signal.

The electronic endoscope apparatus of the first embodiment comprises an electronic endoscope 1 as shown in FIG. The electronic endoscope 1 has an elongated and flexible insertion portion 2, for example, and a large-diameter operation portion 3 is connected to the rear end of the insertion portion 2. A flexible cable 4 extends laterally from the rear end of the operation section 3, and a connector 5 is provided at the tip of the cable 4. The electronic endoscope 1 is connected via the connector 5 to a video processor 6 including a light source device and a signal processing circuit. Further, a monitor 7 is connected to the video processor 6.

On the distal end side of the insertion portion 2, a rigid distal end portion 9 and a bending portion 10 adjacent to the distal end portion 9 and capable of being curved backward are sequentially provided. Further, by rotating the bending operation knob 11 provided on the operation portion 3, the bending portion 10 can be bent in the horizontal direction or the vertical direction. Further, the operation section 3 is provided with an insertion opening 12 that communicates with a treatment tool channel provided in the insertion section 2.

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

On the other hand, in the video processor 6, there is provided a lamp 21 which emits light in a wide band from ultraviolet light to infrared light. As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used.
The xenon lamp and strobe lamp emit a large amount of ultraviolet light and infrared light as well as visible light. This lamp 2
1, the power source 22 supplies electric power. A rotary filter 50, which is rotationally driven by a motor 23, is arranged in front of the lamp 21.
Filters that transmit light in the respective wavelength regions of red (R), green (G), and blue (B) for normal observation are arranged in the rotary filter 50 along the circumferential direction.

The rotation of the motor 23 is controlled and driven by a motor driver 25.

After passing through the rotary filter 50, R, G,
The light that is time-sequentially separated into the lights of the respective wavelength regions of B is further incident on the incident end of the light guide 14, is guided to the tip portion 9 through the light guide 14, and from the tip portion 9. The light is emitted to illuminate the observation site.

The return light from the observation site due to this illumination light is imaged on the solid-state image pickup device 16 by the objective lens system 15 and photoelectrically converted. A drive pulse from a driver circuit 31 in the video processor 6 is applied to the solid-state imaging device 16 via the signal line 26, and the drive pulse is used to read and transfer.

The video signal read from the solid-state image pickup device 16 is input to the preamplifier 32 provided in the video processor 6 or the electronic endoscope 1 through the signal line 27. ing. This preamp 3
The video signal amplified in 2 is input to the process circuit 33, subjected to signal processing such as γ correction and white balance, and converted into a digital signal by the A / D converter 34.

The output video signal of the A / D converter 34 is
Similar to the conventional example, the data is selectively stored in the memories (36a, 36b, 36c), synchronized by the memory controller 60, converted into an analog signal by the D / A converter 37, subjected to predetermined processing, and output. It is like this.

On the other hand, the timing generator 42 and the memory controller 60 consist of the mode changeover switch 6
The operation mode is changed according to the instruction of the mode changeover switch.

The operation of the thus configured electronic endoscope apparatus will be described. The normal operation is the same as that of the conventional example shown in FIG. 10, and the exposure time for each field is 1/120 second. Further, the read mode of the solid-state image pickup device is 2-line simultaneous read interlace.

In FIG. 3, the combination of A is used for reading odd lines, and the combination of B is added for reading even lines.

Here, when the sensitivity is increased, the mode of the timing generator 42 is changed by the mode changeover switch 61, the drive of the solid-state image pickup device 16 is changed, and the exposure time is set to 1/60 seconds.

With respect to driving, only the read cycle changed to 1/60 seconds, and the interlaced read method and the rotation speed of the filter were not changed. The read signal from the solid-state image sensor 16 at this time is as shown in FIG. In synchronization with the read signal, the video signals are synchronized in the memory 36 (FIG. 4 (b)). In this case, a 1-frame screen is formed in 6 field times, which may increase the color misregistration element. However, in the case of an endoscope, if it is necessary to increase the sensitivity, it may be a far point. Because there are many, it does not matter.

FIG. 5 shows a method in which the read cycle is set to 1/60 second and the two-line simultaneous read is used, but the non-interlaced read is used when the sensitivity is increased. For example, the combination of FIG. 3A is added and read in both the odd field and the even field. This non-interlaced signal is stored in memory 3
Simultaneous by 6a, 36b, 36c. In the case of this method, a screen of one frame can be obtained in three fields, so that the color shift is reduced as compared with FIG. Also, the vertical appearance can be improved by performing the vertical interpolation.

The above two sensitivity increasing methods are used for screen information,
The switching may be performed according to the dimming information or the user's intention.

Next, the second embodiment will be described. 6 and 7 relate to the second embodiment, FIG. 6 is a block diagram showing a configuration of a main part of the electronic endoscope apparatus, and FIG. 7 is a read timing of the solid-state image pickup device at the time of increasing sensitivity and synchronization. It is an explanatory view explaining an output signal.

As shown in FIG. 6, the electronic endoscope apparatus of the second embodiment is almost the same as that of the first embodiment, and the different points are shown in Japanese Patent Application No. 3-275691. In addition, an interpolation circuit 62 for interpolating the information stored in the memories 36a, 36b, 36c and the memories 36a, 36, so that one screen can be formed by three fields by interpolation.
SW1 to switch the outputs of b and 36c and the interpolation circuit 62
The rest of the configuration is the same as that of the first embodiment in that SW3 is provided, and therefore the description thereof is omitted.

The reading of the solid-state image pickup device is as shown in FIG. The electronic endoscope apparatus of the second embodiment can improve the vertical resolution as compared with the method of FIG. 5 with the same color shift as that of the method of FIG. 4 of the first embodiment. Other effects are the same as those of the first embodiment. As in the first embodiment, the sensitivity increasing method may be switched according to screen information, dimming information, or the user's intention.

Next, a third embodiment will be described. FIG. 8 is a block diagram showing the configuration of the main part of the electronic endoscope apparatus according to the third embodiment.

The third embodiment is a combination of the first embodiment with a light control means and an AGC (auto gain controller).

The video signal output from the A / D converter 34 is input to the dimming detection circuit 63 and the AGC circuit 64. The output of the AGC circuit 64 is input to the AGC detection circuit 65 and the process circuit 33 as in the first embodiment. The outputs of the dimming detection circuit 63 and the AGC detection circuit 65 are input to the control circuit 66.

Here, in the case of prioritizing the dimming to increase the sensitivity, when the output of the dimming detection circuit 65 becomes less than a predetermined set value, the control circuit 66 is set to the sensitivity up mode and the first embodiment is performed. The driving method shown in the example, that is, the reading cycle of the solid-state image sensor is switched to 1/60 second. At this time, in order to prevent the output of the solid-state imaging device from doubling at the time of switching, the control circuit 66 quickly controls the diaphragm so that the dimming level of the light source becomes 1/2.

Similarly, when the sensitivity increase is controlled by the AGC circuit 64, when the output of the AGC detection circuit 65 becomes less than or equal to a set value, the control circuit 66 is set to the sensitivity up mode, which is shown in the first embodiment. Change to the driving method. At this time, in order to prevent the output of the solid-state image sensor from being doubled at the time of switching, the control circuit 66 controls the AGC.
AGC quickly so that the gain of the circuit 64 becomes 1/2
Control the gain.

These sensitivity enhancements are performed by the dimming detection circuit 63, A
The GC detection circuit 65 may use only one of the information, or may perform the information based on two pieces of information.

Further, this switching is also carried out by the screen information, the light control information, the AGC information, the motion information, etc., and the three reading methods shown in the first and second embodiments (FIGS. 4 and 5).
An appropriate method may be selected from (see FIG. 7) and switched.

From the above, the imaging method is optimally controlled,
The dynamic range of imaging is greatly expanded.

Although the A / D converter is located immediately before the process circuit in each of the embodiments, the present invention is not limited to this, and it may be located anywhere between the solid-state image pickup device and the memory.

Although the encoder output indicates NTSC, it may be a composite signal such as PAL or SECAM.

Further, in each of the embodiments, the reading cycle of each information from the solid-state image pickup device is set to 1/60 seconds while the rotation speed of the filter 50 remains unchanged, but the rotation speed of the filter is changed.
The read cycle from the solid-state image sensor may be 1/60 seconds or more.

[0050]

According to the electronic endoscope apparatus of the present invention, the operation cycle control means controls the operation cycles of the read control means and the write control means based on the control contents instructed by the instructing means. There is an effect that you can up.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an overall configuration of an electronic endoscope apparatus according to a first embodiment.

FIG. 2 is a block diagram showing a configuration of a main part of the electronic endoscope apparatus according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating a reading method of the solid-state imaging device according to the first embodiment.

FIG. 4 is an explanatory diagram for explaining a read timing and a synchronized output signal of the solid-state image sensor for interlaced reading at the time of increasing the sensitivity according to the first embodiment.

FIG. 5 is an explanatory diagram illustrating a read timing of a non-interlaced read solid-state image sensor and a synchronized output signal when sensitivity is increased according to the first embodiment.

FIG. 6 is a block diagram showing a configuration of a main part of an electronic endoscope apparatus according to a second embodiment.

FIG. 7 is an explanatory diagram illustrating a read timing of the solid-state image sensor and a synchronized output signal when the sensitivity according to the second embodiment is increased.

FIG. 8 is a block diagram showing a configuration of a main part of an electronic endoscope apparatus according to a third embodiment.

FIG. 9 is a block diagram showing a configuration of a main part of an electronic endoscope apparatus according to a conventional example.

FIG. 10 is an explanatory diagram for explaining timings of writing and reading to the synchronization memory during the reading period from the solid-state imaging device according to the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope 6 ... Video processor 16 ... Solid-state image sensor 42 ... Timing generator 50 ... Rotation filter 60 ... Memory controller 61 ... Mode switch

Claims (1)

[Claims] 1. A plurality of illumination lights having different wavelength regions are used,
Illuminating means for illuminating in time series, a solid-state image pickup device for picking up a subject image illuminated by the illumination light from the illuminating means, and a solid-state image pickup device which is read from the solid-state image pickup device and obtained corresponding to the plurality of illumination lights. In the electronic endoscope apparatus including a plurality of storage units that respectively store the captured image signals and a generation unit that generates an image signal based on the outputs from the plurality of storage units, the readout of the solid-state image sensor is controlled. Read control means, write control means for controlling writing to the plurality of storage means, operation cycle control means for controlling operation cycles of the read control means and the write control means, and control of the operation cycle control means An electronic endoscope apparatus comprising: an instruction unit for instructing contents.