JPH06331906A - Electronic endoscope device - Google Patents

Abstract

PURPOSE:To continuously generate electric power at the tip of an insert part, and to reduce a solar battery and a smoothing circuit in size and reduce the size of the tip of the insert part by supplying infrared rays which are not sensed by a solid-state image pickup element to the solar battery and generating elec tric energy when electric charges are transferred from the solid-state image pickup element. CONSTITUTION:The light of a light source lamp 21 is transmitted through color filters 22R, 22G, and 22B and passed through a light guide fiber bundle 13 for lighting to irradiate a subject and the solar battery. A beam reflected by the subject passes through an objective 3 and reaches the photodetection surface of a CCD 4 to form an image of the subject. Image signals of the three colors are outputted from the CCD 4 in order to form images in plane sequence, an infrared transmission filter 221R cuts visible light made incident on the light guide fiber bundle 13 for lighting, and when no light is made incident on the CCD 4, charge transfer from the CCD 4 is performed. The solar battery 14 generates the electric energy with the incident light and outputs it to a stabilized power source 15, and the energy is smoothed by a capacitor 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a color switching filter for performing frame-sequential imaging between an incident end of a light guide fiber bundle for illumination of an endoscope and a light source. A solar cell provided at the tip of the insertion portion of the endoscope converts a part of the light energy emitted from the emission end of the light guide fiber bundle for illumination into electric energy, and the electric energy is inserted into the endoscope. The present invention relates to an electronic endoscope device that is used as drive energy for a solid-state image pickup device arranged inside the tip of a section.

[0002]

2. Description of the Related Art In an electronic endoscope apparatus of this type, generally, three color filters of red (R), green (G), and blue (B) are provided in an incident end of a light guide fiber bundle for illumination and a light source. Are sequentially inserted between the solar cell and the solar cell, and light energy is given to the solar cell at that time.

However, it is necessary to prevent light from entering the solid-state image pickup device during transfer of charges from the solid-state image pickup device such as CCD (charge coupled device). It is a completely light-shielding portion that does not pass through, and illumination light does not enter the illumination light guide fiber bundle.

[0004]

However, if the illuminating light does not enter the illuminating light guide fiber bundle during charge transfer, the solar cell does not generate electricity during that time, so that the electric energy for driving the solid-state image pickup device is generated. Will be intermittent, and the overall power generation time will be short.

Therefore, conventionally, it is necessary to use a relatively large solar cell for driving a solid-state image pickup device, and a smoothing circuit for smoothing an intermittent power generation output also becomes large. However, there is a drawback that the tip of the insertion part becomes large.

Therefore, according to the present invention, it is possible to continuously generate electric power in the solar cell provided at the tip of the insertion portion even during the charge transfer from the solid-state image pickup device, and to downsize the solar cell and the smoothing circuit. It is an object of the present invention to provide a simple electronic endoscope device.

[0007]

In order to achieve the above object, the electronic endoscope apparatus of the present invention has a surface sequential type between an incident end of a light guide fiber bundle for illumination of an endoscope and a light source. A color switching filter for picking up the image is arranged, and a part of the light energy emitted from the emission end of the illumination light guide fiber bundle is electrically converted by the solar cell provided at the tip of the insertion portion of the endoscope. In the electronic endoscope apparatus in which the electric energy is converted into energy and used as drive energy for a solid-state image pickup element arranged in the tip of the insertion portion of the endoscope, the color switching filter is used for the illumination. A plurality of color filters sequentially inserted between the incident end of the light guide fiber bundle and the light source, and the illumination light guide between the insertion of each color filter. Is inserted between the incident end and the light source Aibabandoru by infrared is transmitted, characterized in that formed by the infrared transmitting filter visible light is not transmitted.

It should be noted that an infrared cut filter which does not transmit infrared rays but transmits visible light may be provided in the light incident path to the solid-state image pickup device, and the red light is transmitted while electric charges are transferred from the solid-state image pickup device. An outer transmission filter may be inserted between the incident end of the illumination light guide fiber bundle and the light source so that the solar cell outputs electric energy.

[0009]

Embodiments will be described with reference to the drawings. In FIG. 1, an objective lens 3 is provided in a tip 2 of an insertion portion 1 of an endoscope.
The image receiving surface of the solid-state image pickup device 4 formed of, for example, a CCD (charge-coupled device) is arranged at a subject image forming position by.

Further, an infrared cut filter 5 which transmits visible light and blocks infrared rays is arranged between the objective lens 3 and the CCD 4. A drive circuit 6 for driving the CCD 4 and a buffer 7 for impedance conversion of an image signal output from the CCD 4 are both built in the tip 2 of the insertion portion.

An optical / electrical conversion element 8 is connected to a signal input end of the drive circuit 6, and a clock based on an optical pulse sent via an optical fiber 9 for signal transmission inserted in the insertion section 1. The signal is converted into an electric pulse signal by the optical / electrical conversion element 8 and given to the drive circuit 6.

An electric / optical conversion element 10 is connected to the output end of the buffer 7, and is converted into an optical pulse signal via an optical fiber 11 for transmitting an image signal inserted in the insertion section 1. Image signal is transmitted.

Numeral 13 is a light guide fiber bundle for illumination, and its output end 13a is directed in the same direction as the observation direction by the objective lens 3, and a part thereof is branched to form the solar cell 1.
It is arranged so as to face the light receiving surface of No. 4.

The relative spectral sensitivity characteristic of this solar cell 14 is
For example, as shown in FIG. 2, the sensitivity is in the range from the long wavelength region of visible light having a wavelength of 600 nm to the infrared region having a wavelength of 1000 nm.

Returning to FIG. 1, the electric energy output end of the solar cell 14 is connected to a stabilizing power supply 15 which is a power supply for driving electric energy of the CCD 4, and a voltage smoothing capacitor 16 is connected to the connection portion. There is.

Then, from the output end of the stabilized power source 15, C
CD 4, drive circuit 6, buffer 7, optical / electrical conversion element 8
And electrical energy is supplied to the electrical / optical conversion element 10.

A light source lamp 21 for emitting light rays in the visible and infrared regions is provided at an incident end 13b of a light guide fiber bundle 13 for illumination in a light source device / video processor 20 provided so that an endoscope can be connected. A color filter turntable 22 is disposed facing each other, and the color filters 22R, 22G, and 22B of three colors of red (R), green (G), and blue (B) are attached between them. There is.

Reference numeral 23 is a motor for rotationally driving the color filter turntable 22, and 24 is a drive circuit thereof. By rotating the three color filters 22R, 22G, 22B, the light guide fiber bundle 13 for illumination is provided. The color of the illumination light incident on is sequentially switched to red, green, and blue, and a so-called field-sequential color image can be captured.

An electrical / optical conversion element 26 is arranged at the incident end of the signal transmitting optical fiber 9. Further, an optical / electrical conversion element 27 is arranged at the emission end of the image signal transmitting optical fiber 11, and its output end is connected to a video processor 29 via a buffer 28, and the image processed there is displayed on a monitor 30. Is displayed.

The output end of the system controller 32 for controlling the entire system is the driver 24 of the motor 23.
Is connected to the timing generator 33, and the clock pulse output from the timing generator 33 is
The signal is given to the driver 24 of the motor 23, the video processor 29 and the electric / optical conversion element 26, converted into an optical signal and passed through the optical fiber 9 for signal transmission, and further converted into an electric signal by the optical / electrical conversion element 8. Drive circuit 6 for CCD 4
Is given to.

As described above, the driving pulse of the CCD 4 is not transmitted as an electric signal in the endoscope but is transmitted as an optical signal and is converted from light to electricity at the tip 2 of the insertion portion. It is not necessary to provide a matching circuit or the like for compensating the deterioration of the waveform during the transmission of the drive pulse, and the configuration of the signal processing unit can be simplified.

As the clock pulse to be transmitted,
Three types of clock pulses are required for vertical transfer, horizontal transfer, and anti-blooming gate to prevent leakage of charges, but signal transmission is performed by making the light wavelength of each clock pulse different from each other. Optical fiber 9
Can also be formed by a single optical fiber.

As shown in FIG. 3, the color filter turntable 22 transmits infrared rays between the three color filters 22R, 22G and 22B of three colors of red (R), green (G) and blue (B). Infrared transmission filter 22I that does not transmit visible light
It is formed by R.

FIG. 4 shows the spectral sensitivity characteristics of the infrared transmission filter 22IR, which transmits infrared rays having a wavelength longer than 750 to 880 nm well. The broken line indicates the sensitivity characteristic of the solar cell 14, and the area of the shaded area that receives the infrared light that passes through the infrared transmission filter 22IR is as large as the sensitive area of the visible region. Therefore, the solar cell 14
Emits light energy in the infrared region, and outputs electric energy at the same level as that of light incident in the entire visible region.

The spectral sensitivity characteristics of the three color filters 22R, 22G and 22B of the color filter turntable 22 are as shown in FIGS. 5 to 7, and here, red (R), green (G) and blue. The one having the characteristic of transmitting the light rays only in the region (B) is used.

According to the electronic endoscope apparatus having such a configuration, the motor 23 rotates the color filter turntable 22 so that the light including the infrared rays emitted from the light source lamp 21 is sequentially filtered by each color filter. 22R, 22
After passing through G and 22B, the subject is illuminated through the illumination light guide fiber bundle 13 and a part of the solar cell 14 is illuminated.

At that time, the respective color filters 22R, 22G, 2
The infrared transmission filter 22IR between 2B is the light source lamp 21.
While being positioned between the illuminating light guide fiber bundle 13 and the illuminating light guide fiber bundle 13, only infrared rays are applied to the illuminating light guide fiber bundle 13 to illuminate the subject, and a part of the solar cell 14 is irradiated.

Then, the light beam reflected by the object passes through the objective lens 3 and reaches the light receiving surface of the CCD 4, where an image of the object is formed. At that time, only visible light reaches the CCD 4 by passing through the infrared cut filter 5.
However, if a solid-state image sensor that is insensitive to infrared rays is used, the infrared cut filter 5 does not necessarily have to be provided.

In this way, the image signals of the three colors of red, green and blue are sequentially output from the CCD 4 to perform frame-sequential imaging, and the infrared transmission filter 22IR makes visible to the illumination light guide fiber bundle 13. When the light is cut off and there is no light entering the CCD 4, CC
Charge transfer from D4 is performed.

The solar cell 14 generates electrical energy by the incident light from the illumination light guide fiber bundle 13 and outputs it to the stabilizing power source 15. The output voltage is smoothed by the capacitor 16.

FIG. 8 shows the terminal voltage of the stabilized power supply 15 corresponding to the color of the illumination light, (a) shows the capacitor 16
The power input voltage V1 in the case where there is no charge, and a large voltage is obtained by the light rays in the infrared region when the charge is transferred from the CCD 4.

Since the capacitor 16 is connected, the power supply input voltage V1 is smoothed as shown in (b), and the power supply output voltage V2 is stable and constant as shown in (c). It becomes a voltage and is supplied to each part as electric energy for driving the CCD 4 and the like.

Each color filter 22R, 22G, 22
If the spectral sensitivity characteristic of B is set such that light rays in the infrared region are also transmitted, as shown in FIGS. 9 to 11, for example, a larger solar cell output can be obtained during illumination with each color. Alternatively, it may be performed only for the blue filter 22B in which the sensitivity of the solar cell 14 is low.

[0034]

According to the electronic endoscope apparatus of the present invention, when electric charge is transferred from the solid-state image sensor, infrared rays that are not sensed by the solid-state image sensor are applied to the solar cell to generate electric energy. The power generation is continuously performed, and as a result, the solar cell and the smoothing circuit can be downsized, and the tip of the insertion portion of the endoscope can be downsized.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an electronic endoscope apparatus of an embodiment.

FIG. 2 is a spectral sensitivity characteristic diagram of the solar cell of the example.

FIG. 3 is a schematic view of a color filter turntable of an embodiment.

FIG. 4 is a spectral sensitivity characteristic diagram of the infrared transmission filter of the example.

FIG. 5 is a spectral sensitivity characteristic diagram of the red filter of the example.

FIG. 6 is a spectral sensitivity characteristic diagram of the green filter of the example.

FIG. 7 is a spectral sensitivity characteristic diagram of the blue filter of the example.

FIG. 8 is a power supply voltage diagram of the example.

FIG. 9 is a spectral sensitivity characteristic diagram of a red filter of another example.

FIG. 10 is a spectral sensitivity characteristic diagram of a green filter of another embodiment.

FIG. 11 is a spectral sensitivity characteristic diagram of a blue filter of another example.

[Explanation of symbols]

 4 CCD (solid-state imaging device) 13 Illumination light guide fiber bundle 14 Solar cell 21 Light source lamp 22 Color filter turntable 22R, 22G, 22B Color filter 22IR Infrared transmission filter

Claims (3)

[Claims] 1. A color switching filter for performing frame-sequential imaging is arranged between an incident end of a light guide fiber bundle for illumination of an endoscope and a light source, and a tip of an insertion portion of the endoscope. A part of the light energy emitted from the emission end of the illumination light guide fiber bundle is converted into electric energy by the solar cell provided in, and the electric energy is arranged in the tip of the insertion portion of the endoscope. In the electronic endoscope apparatus adapted to be used as drive energy for a solid-state image pickup device, a plurality of color filters in which the color switching filter is sequentially inserted between an incident end of the light guide fiber bundle for illumination and the light source. And is inserted between the incident end of the light guide fiber bundle for illumination and the light source during the insertion of each color filter, and infrared rays are transmitted. Is formed of an infrared transmission filter that does not transmit visible light. 2. The electronic endoscope apparatus according to claim 1, wherein an infrared cut filter which does not transmit infrared rays but transmits visible light is provided in a light incident path to the solid-state image pickup element. 3. The infrared transmission filter is inserted between an incident end of the light guide fiber bundle for illumination and the light source while electric charges are transferred from the solid-state image pickup device, and the infrared transmission filter is inserted from the solar cell. The electronic endoscope apparatus according to claim 1, wherein electric energy is output.