JP2866658B2 - Endoscope device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an endoscope apparatus in which an auxiliary light source is turned on when a main light source is turned off, and at the same time, the amplification degree of an image signal is switched to a high value. About.

[Prior art] In recent years, by inserting an elongated insertion portion into a body cavity,
Endoscopes (electronic endoscopes or fiberscopes) capable of observing and examining organs and the like in body cavities have been widely used.

In addition to medical use, endoscopes are used for observing and inspecting an object in a pipe of a boiler, a machine, a chemical plant, or the like, or in a device, for industrial use.

Further, various types of electronic endoscopes using a solid-state imaging device such as a charge-coupled device (CCD) as imaging means have been used. This electronic endoscope has a higher resolution than a fiberscope,
It has advantages such as easy recording and reproduction of a screen, and easy image processing such as enlargement of an image and comparison of two screens.

When observing the inside of a body cavity using the fiber scope and the electronic endoscope, a light source device is connected to the fiber scope or the electronic endoscope, and illumination light from the light source device is supplied into the body cavity. I have. In this light source device, illumination light is guided to the end of the endoscope through a light guide, and a large amount of light is required. Therefore, a xenon lamp is often used. Is about 200 to 300 hours, and in some cases, the lamp goes out (the lamp being turned on suddenly goes off) in a shorter time due to variations in lamp quality. If the light source lamp goes out during an endoscopy or an endoscopic procedure, there is a danger of death. Therefore, in order to avoid such a danger, an emergency light is generally provided in the light source device in addition to the light source lamp.

Various light source devices provided with such emergency lights have been proposed. For example, a prior art example disclosed in Japanese Patent Application Laid-Open No. Sho 60-29129 is such that when an auxiliary light source is prepared and the discharge lamp as a main light source is turned off, the auxiliary light source is replaced with a discharge lamp. It is.

The configuration of this prior art example is schematically shown in FIG. In this prior art example, during normal operation, the control circuit 1
The main light source lighting circuit 2 is actuated by the control signal from, so that the discharge lamp 3 is turned on. Then, the light from the discharge lamp 3 passes through the lens 5 via the filter of the turret plate 4 and is guided to the incident end of the light guide 6 of the electronic endoscope.

As shown in FIG. 5, the turret plate 4 includes two mesh filters 4a and 4b, an infrared cut filter 4c, and an emergency light 4d. During normal operation, that is, when the discharge lamp 3 is turned on. Is performed, one of the two mesh filters 4a and 4b is selected according to the brightness of the discharge lamp 3.
One is selectively interposed in the illumination light path. When the discharge lamp is turned off, the non-lighting detection circuit 11 detects the non-lighting state, and sends a signal indicating this to the control circuit 1. Then, a drive signal is sent from the control circuit 1 to the motor drive circuit 14, and the motor 15 is rotated by the drive signal, whereby the turret plate 4 is driven to rotate and the emergency light 4d as an auxiliary light source is driven.
Is provided in the illumination light path, and the emergency light 4d is turned on by a signal from the auxiliary light source lighting circuit 12.

[Problems to be Solved by the Invention] In this prior art example, the brightness of the auxiliary light source is not only for an optical endoscope having an image transmission optical system such as a fiberscope, but also for an electronic endoscope using a solid-state imaging device. Because the field of view of the endoscope is secured only by itself, expensive and large power-consuming lamps such as halogen lamps must be used as auxiliary light sources, and the scale of the circuit becomes larger. There is a problem that must be.

[Object of the Invention] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide an endoscope apparatus that can secure a field of view in a range where safety can be maintained by using a low-cost lamp with low power consumption as an auxiliary light source.

[Means for Solving the Problems] The endoscope apparatus according to claim 1, wherein an imaging unit that captures an image of the observation target, a first light source that emits illumination light that illuminates the observation target, and the first light source. A non-lighting detecting means for detecting a non-lighting state of the light source, a second light source which is lit at a light amount lower than the first light source based on a detection signal from the non-lighting detecting means, and an image pickup means. A first amplification factor for amplifying the obtained image signal, an amplification factor setting unit for setting a second amplification factor larger than the first amplification factor, and the detection signal from the non-lighting detection unit. When the first light source is turned on, the image signal is amplified at the first amplification factor, and when the second light source is turned on, the image signal amplification factor is changed so as to amplify the image signal at the second amplification factor. And changing means.

The endoscope apparatus according to claim 1, wherein the image signal is amplified at a first amplification factor when the first light source is turned on based on the detection signal from the non-lighting detection means, and the second light source is turned on. Sometimes, the changing means changes the amplification rate of the image signal so that the image signal is amplified at the second amplification rate.

In the endoscope apparatus according to claim 2, the ratio between the first amplification factor and the second amplification factor in the endoscope device according to claim 1 is determined by comparing the light amount of the first light source with the light amount of the first light source. It is characterized in that the ratio is approximately the reciprocal of the light amount of the second light source.

According to the endoscope apparatus according to claim 2, the level of the image signal obtained when the first light source is turned on and the second
, The level of the image signal obtained when the light source is turned on becomes substantially equal.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of an endoscope apparatus, and FIG. 2 is a view showing the entire endoscope apparatus.

As shown in FIG. 2, the endoscope device 21 includes an endoscope 22,
A light source device 23 that supplies illumination light to the endoscope 22, a control device 24 that processes an output signal from the endoscope 22, and a monitor that displays a video signal output from the control device 24 on a screen It consists of 25.

The endoscope 22 includes an elongated insertion portion 27, a large-diameter operation portion 28 continuously provided on the rear end side of the insertion portion 27, and a light guide extended from a side portion of the operation portion 28. And a universal cord 29 having a built-in signal cable.

A rigid distal end portion 31 is provided on the distal end side of the insertion portion 27, and a bendable portion 32 that is bendable on the rear side adjacent to the distal end portion 31 is provided. Further, behind the curved portion 32, a flexible flexible portion 33 is continuously provided. The bending section
The 32 can be bent in the up / down / left / right directions by operating a bending operation knob 34 provided on the operation unit 28.

A light guide and signal connector 36 is provided at the rear end of the universal cord 29, and is connected to the light source device 23 and the control device 24 at the same time. The light source device 23 and the control device 24 are connected by a signal cable 38 provided with connectors 37 at both ends.

In FIG. 1, the connector 36 connected to the light source device 23 is provided with an incident end face 42 of a light guide 41 formed by a fiber bundle. The light guide 41 is provided between the universal cord 29 and the operation unit.
28 and the inside of the insertion portion 27. Further, a discharge lamp 43 as a main light source is provided in the light source device 23, and the discharge lamp 43 and an incident end surface 42 of the light guide 41 are provided.
The turret plate 4 and the condensing lens 45 are provided on the optical path that connects

The turret plate 4 has the same configuration as the conventional one shown in FIG. 5, and as described above, the two mesh filters 4a and 4b, the infrared cut filter 4c, and the emergency light source as an auxiliary light source. Lamp 4d, and usually includes two mesh filters according to the brightness of the discharge lamp 43.
One of 4a and 4b is selected and interposed in the illumination light path.

The light emitted from the discharge lamp 43 passes through one of the mesh filters 4a and 4b provided on the turret plate 4, and then is condensed on the incident end face 42 of the light guide 41 via the condenser lens 45. Is guided to the distal end portion 31 of the endoscope 22 through the light guide 41 and emitted therefrom,
The object is illuminated.

On the other hand, an objective lens 47 is provided at the distal end portion 31, and a CCD 48 is provided at an image forming position of the objective lens 47. Then, of the irradiated light, the light reflected from the subject is formed on the CCD 48 through the objective lens 47, and is photoelectrically converted into an electric image signal. Then, this image signal is input to an amplification circuit 49 as amplification means. The amplification circuit 49 includes an amplification degree changeover switch 50 as amplification degree changeover means. The amplification degree changeover switch 50 is turned on during normal operation, that is, when the main light source is turned on, and is turned off when the main light source is turned off. Approximately 9 times when switch 50 is on, approximately 9 times when switch 50 is off
100 times. The output of the amplifying circuit 49 is input to a process circuit (not shown) and is converted into a video signal.

The light source device 23 includes a main light source lighting circuit 51 for lighting the discharge lamp 43, and a non-lighting detection circuit as non-lighting detection means for detecting when the discharge lamp 43 is not lit.
53, an auxiliary light source lighting circuit 54 for lighting the emergency light 4b when the non-lighting state of the discharge lamp 43 is detected by the non-lighting detection circuit 53, and interposing the emergency light 4b in the illumination light path. A motor 56 for rotating and driving the turret plate 4, a motor control circuit 57 for controlling the motor 56,
A control circuit 52 for controlling the main light source lighting circuit 51, the auxiliary light source lighting circuit 54, and the motor control circuit 57 is provided.

Next, the actual operation of the first embodiment having the above configuration will be described.

During normal operation, the main light source lighting circuit 51 is operated by a control signal from the control circuit 52, and thereby the discharge lamp 43 is turned on. The light from the discharge lamp 43 passes through one of the mesh filters 4 a and 4 b provided on the turret plate 4,
The light is condensed at the incident end 42 of the light guide 41, guided by the light guide 41 to the distal end portion 31 of the electronic endoscope 22, and emitted therefrom.
The subject is irradiated. Then, of the illumination light, the light reflected from the subject is imaged on the CCD 48 by the objective lens 47, and is converted into an electric image signal by the CCD 48. Then, this image signal is then supplied to an amplification degree switching circuit.
The signal is input to 49 and amplified about 9 times, and then input to a process circuit (not shown) to be converted into a video signal.

When the discharge lamp is turned off, the non-lighting detection circuit 53 detects the non-lighting state of the discharge lamp 43 and sends a signal indicating this to the control circuit 52. In response to this signal, the control circuit 52 sends a control signal to the motor drive circuit 57, controls the motor 56, rotates the turret plate 4, and the emergency light 4b is interposed in the illumination light path, The light is turned on by the light source lighting circuit 54. At the same time, the amplification degree switch 50 in the amplifier circuit 49 is turned off by the signal from the control circuit 52. Thereby, the amplification degree of the amplifier circuit 49 is switched to 100 times.

By the way, in the first embodiment, in order to reduce the size and cost, a lamp having a brightness of about 1/10 as compared with the discharge lamp is used as an auxiliary light source, so that the amount of illumination light is small. Become. In order to compensate for this small amount of light, the amplification degree of the image signal is set to about 10 times that at the time of lighting of the discharge lamp as described above, so that an image from the electronic endoscope can be identified. When switching the amplification degree in this way, the S / N ratio of the image signal deteriorates, but the use of an emergency light is
There is no problem in use because the discharge lamp is turned off and only when the endoscope is pulled out or during a minimal emergency during the operation.

As described above, according to the present embodiment, when the discharge lamp is turned off, the emergency light is turned on, and at the same time, the amplification degree of the image signal is switched to a large value. Also, the field of view of the endoscope can be secured.

FIG. 3 shows a second embodiment of the present invention. In the second embodiment, the present invention is applied to an endoscope apparatus of an RGB plane sequential system, and a discharge lamp is provided in the light source device 23 of the first embodiment.
A diaphragm unit 61 for adjusting the light amount of the light emitted from 43; a diaphragm control circuit 62 for controlling the diaphragm unit 61; a lens 63 for passing the light whose light amount has been adjusted by the diaphragm unit 61; Filter 64 for separating light from the light into each of the RGB wavelength ranges, and a motor 65 for driving the rotation filter 64 to rotate.
A rotation control circuit 66 for controlling the rotation of the motor 65,
A motor 67 for moving the rotary filter 64 out of the illumination light path, and a movement control circuit 68 for controlling the movement of the rotary filter 64 by controlling the motor 67 are provided.

The second embodiment has the same configuration as that of the first embodiment except that the above-described circuits are provided, and the same elements are denoted by the same reference numerals as those in the first embodiment.

At the time of normal operation, the light emitted from the discharge lamp 43 passes through the infrared filter 4c of the turret plate 4, is then stopped down by the stop unit 61 controlled by the stop control circuit 62, passes through the lens 63, After being separated in time series into each of the RGB wavelength regions by a rotation filter 64 driven to rotate by a motor 65, an incident end face 42 of a light guide 41 is condensed by a condenser lens 45.
The light guide 41 condenses the light into the electronic endoscope 22.
, And is emitted therefrom, and illuminates the subject as RGB plane-sequential illumination light. Then, of the illumination light, the light reflected from the subject is imaged on the CCD 48 by the objective lens 47, and is converted into an electric image signal by the CCD 48. And this image signal is then
After being input to the amplifier circuit 49 and amplified by about 9 times, it is input to a process circuit (not shown) and converted into a video signal.

When the discharge lamp 43 is turned off, the amplification of the amplification degree switching circuit 49 is switched to 100 times by the same operation as in the first embodiment.

In addition, in order to increase the amount of light even slightly, the diaphragm unit 61 is fully opened by a control signal from the diaphragm control circuit 62, and the motor 67 is rotated by a signal output from the movement control circuit 68. The filter 64 is removed from the illumination light path.

If the rotating filter 64 is removed from the illumination light path, a color image cannot be obtained, but the emergency light is used when the discharge lamp is turned off and the scope is removed, as described above. Alternatively, there is no problem in use because it is only a minimal emergency during the operation.

As described above, according to the present embodiment, in the RGB plane sequential type electronic endoscope apparatus, when the discharge lamp is turned off, the rotary filter is removed from the illumination optical path and the stop is fully opened to increase the light amount. Thus, a bright image can be obtained.

In the second embodiment, the color imaging method is described as a frame sequential method. However, the present invention is not limited to this and can be applied to a simultaneous type in which a color filter array is provided on the front surface of a CCD.

In each of the above embodiments, the type in which the light source device and the control device are separate has been described, but this may be an integrated type.

Further, the present invention can be applied not only to the electronic endoscope apparatus of each of the above embodiments but also to a combination of a fiberscope and an external camera.

[Effect of the Invention] According to the endoscope apparatus according to claim 1, an image signal obtained when the second light source having a lower light intensity than the first light source is turned on is converted into a second image signal which is larger than the first amplification factor. Since the image is amplified at the amplification rate, it is possible to secure an image with a brightness that does not cause any problem on safety.

According to the endoscope apparatus of the second aspect, when an observer observes the obtained image on a monitor or the like, even when the second light source having a lower light intensity than the first light source is switched, the second image is displayed. Since the level of the image signal obtained when the first light source is turned on and the level of the image signal obtained when the second light source is turned on can be made substantially equal, the observer can feel comfortable. An image on the monitor can be captured.

[Brief description of the drawings]

FIGS. 1 and 2 relate to a first embodiment of the present invention, and FIG.
FIG. 2 is a block diagram showing the configuration of the endoscope apparatus, FIG. 2 is an explanatory view showing the entire endoscope apparatus, and FIG. 3 is the configuration of the endoscope apparatus according to the second embodiment of the present invention. 4 and 5 relate to a prior art example, and FIG. 4 is a block diagram showing a configuration of a light source device for an endoscope according to a prior art example.
The figure shows the configuration of the turret plate. 21 ... Endoscope device, 23 ... Light source device 43 ... Discharge lamp, 49 ... Amplification circuit 50 ... Amplification degree changeover switch 51 ... Main light source lighting circuit, 52 ... Control circuit 53 ... Non-lighting detection Circuit 54 …… Auxiliary light source lighting circuit 56 …… Motor 57 …… Motor control circuit

Claims (2)

(57) [Claims] An imaging unit configured to image an observation target; a first light source that emits illumination light for illuminating the observation target; a non-lighting detection unit configured to detect a non-lighting state of the first light source; Based on the detection signal from the non-lighting detection means, the first
A second light source that is lit with a light amount lower than that of the first light source, a first amplification factor for amplifying the image signal obtained by the imaging unit, and a second amplification factor that is larger than the first amplification factor. Amplification factor setting means, based on the detection signal from the non-lighting detection means, amplifies an image signal at the first amplification factor when the first light source is turned on, and amplifies the image signal when the second light source is turned on. Changing means for changing the amplification factor of the image signal so as to amplify the image signal at the second amplification factor. 2. The method according to claim 1, wherein the ratio between the first amplification factor and the second amplification factor is substantially the reciprocal of the ratio between the light intensity of the first light source and the light intensity of the second light source. Item 2. The endoscope apparatus according to Item 1.