JPH05168590A - Endoscope apparatus - Google Patents

Abstract

PURPOSE:To prevent overlooking of a lesion or the like by controlling a quantity of illumination light according to a luminance level of a low luminance part. CONSTITUTION:An inserting part of an electronic type endoscope is inserted into a living body to observe the inner part of a lumen branched off a bronchus. for instance. A dimming signal is inputted into an iris driver 23 in a light source device 2 and an iris blade 25 of a stop is opened or closed by a value corresponding to the level of the dimming signal based on a bottom (peak) value to adjust the quantity of an illumination light from a light distribution lamp. The larger the quantity of dimming light, the more the iris blade 25 of the stop is opened to increase the quantity of the illumination light. With this adjustment, a dimming is performed automatically to keep the level of the illumination suitable for a part which is observed darkest in a field observation, in this case, namely, the inner part of the lumen branched off the bronchus. This constitution prevents the overlooking of a lesion or the like at a part which is too dark to see so far, for example, the inner parts of the branches of the bronchus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an endoscope apparatus provided with a means for generating an automatic light control signal.

[0002]

2. Description of the Related Art A medical endoscope is used for observing the inside of a body cavity, but the inside of the body cavity is dark and an illuminating means is required. In an electronic endoscope, due to the dynamic range of a solid-state image sensor such as a CCD, halation occurs if the illumination is too bright. Also, it is difficult to observe if it is too dark. Therefore, it is necessary to change the light amount of the illumination in order to stabilize the brightness of the observed image at a substantially constant level. As such a light control means, average photometry and peak photometry have been proposed.

In the average photometry, the light is adjusted so that the average brightness of the entire image becomes substantially constant. Therefore, if there is a convex portion such as a polyp, this becomes a near view, and even if the amount of light is appropriate in the background, in the near view. Excessive light intensity causes halation.

On the other hand, in peak photometry, since such a peak value is detected and the light is adjusted so that the brightness at the peak has a substantially constant image brightness, halation does not occur. Instead, the areas other than the peak become dark.

[0005]

As described above, the average photometry and the peak photometry have their respective advantages and disadvantages, and can be observed in a good image state by properly using them according to the object to be observed.

However, for example, it is difficult to observe if there are many branches such as the bronchus as an observation target, and the depth of the branch is narrow and very dark, and it is difficult to observe such a dark portion by average photometry or peak photometry. It was inappropriate. When the peak photometry is performed, the inner part of the lumen of the bronchus becomes very dark and almost no observation is possible. Even when the average photometry is performed, sufficient brightness cannot be obtained, which is unsuitable for observation.

The present invention has been made in view of the above circumstances. For example, even a dark portion such as the back of a branch of a bronchus is illuminated with appropriate brightness so that it can be observed in detail, so that a lesion or the like is overlooked. An object of the present invention is to provide an endoscope device that can prevent

[0008]

The endoscope apparatus of the present invention comprises:
An endoscopic device that has an illuminating unit for an object, processes an output from an image sensor and outputs a video signal, and a detecting unit that detects a luminance level of a low-luminance portion obtained from the video signal, And means for controlling the amount of illumination light of the illumination means according to the output of the detection means.

[0009]

With this configuration, the detecting means detects the luminance level of the low luminance part obtained from the video signal, and the controlling means controls the illumination light amount of the illuminating means in accordance with the output of the detecting means. Therefore, even if there are many branches, such as the bronchus, that have a lower brightness than the surroundings, such as the interior of the lumen, the bronchus is adjusted to an illumination intensity suitable for imaging. You can observe the parts in detail.

[0010]

Embodiments of the present invention will be described with reference to the drawings. 1 to 6 relate to a first embodiment of the present invention, FIG. 1 is a circuit diagram showing a specific configuration example of a bottom photometry circuit, FIG. 2 is an overall configuration diagram of an endoscope apparatus, and FIG. 4 is a cross-sectional view of the tip of the mirror, FIG. 4 is a block diagram of the endoscope device, FIG. 5 is a waveform diagram for explaining the operation of the circuit shown in FIG. 1, and FIG. 6 is an explanatory diagram showing the effect of the present endoscope device. Is.

An endoscope apparatus 60 shown in FIG. 2 is an electronic endoscope 1, a light source apparatus 2 for supplying illumination light to a subject through the electronic endoscope 1, and an electronic endoscope. A signal processing device 3 for converting an electric signal output by the image pickup device 1 into a standard video signal and outputting a signal for automatic light control described later;
The monitor 4 is provided for displaying the video signal output by the signal processing device 3 as an endoscopic image.

The endoscope 1 is composed of an elongated insertion portion 5, an operating portion 6 and a universal cable 7. The endoscope 1 is a universal
The connector 7a provided at the end of the cable 7 is connected to the light source device 2, and the connector 7a is connected to the connection cable 8
Is connected to the signal processing device 3. Further, the light source device 2 and the signal processing device 3 are connected by a signal cable 25, and the signal processing device 3 and the monitor 4 are connected by a signal cable 26, thereby configuring a system of an endoscope device. ing.

FIG. 3 shows the internal structure of the distal end side of the insertion portion 5 of the endoscope 1. The light guide 11 having the emission end provided at the tip of the endoscope insertion portion 5 shown in FIG. 3 is inserted through the universal cord 7 of the endoscope 1 and transmits the illumination light supplied from the light source device 2. , Via the light distribution lens 11a,
It is designed to illuminate the subject. The reflected light from the subject is imaged on the light receiving surface of a CCD 10 as a solid-state image pickup device via a condenser lens 9 provided at the tip of the endoscope insertion portion 5 and a lens 9a. The CC
D10 converts the light incident on the light receiving surface into an electric signal,
The signal is transmitted to the signal processing device 3 via the universal cord 7 and the signal cable 27 inserted through the connection cable 8 and displayed as an endoscopic image on the monitor 4.

FIG. 4 shows the light source device 2 and the signal processing device 3.
The internal structure is shown. The CC disposed at the tip of the endoscope 1
D10 is driven by the CCD driver 12 of the signal processing device 3 at a timing based on the timing generator 19, and the subject image formed by the CCD 10 is an electrical signal, and the correlated double sampling circuit (C) of the signal processing device 3 is used.
DS) 13 and processed by the luminance signal processing unit 14 and the color signal processing unit 15. The brightness signal Y is transmitted from the brightness signal processing unit 14 and the color difference signals R-Y and B-Y are transmitted from the color signal processing unit 15 to the encoder unit 16 and displayed as an image on the monitor 4.

Further, the brightness signal Y is selectively transmitted from the brightness signal processing section 14 to the average photometry circuit 17 and the bottom photometry circuit 18 as a detecting means via the photometry system changeover switch 22. Then, the signal processing device 3
Is operated by operating the operation panel 20 installed on the exterior of the device 3, the CPU 21 sends a signal for switching the photometry method switch 22, and selects either the average photometry circuit 17 or the bottom photometry circuit 18. However, the dimming method is switched. A light control signal is generated in each of the average photometry circuit 17 and the bottom photometry circuit 18. This dimming signal is supplied to the light source device 2.

On the other hand, the light source device 2 includes a light distribution lamp (not shown) which emits white light by a power source supplied, a concave mirror (not shown) which reflects the white light of the light distribution lamp into a parallel light beam, and a parallel light beam. A diaphragm having an iris blade 25 which is provided in the middle of the optical path of the iris blade and which controls the amount of illumination light, a condenser lens (not shown) which collects the illumination light focused by this diaphragm, and an opening / closing drive of the iris blade 25. And the iris that indicates the opening / closing amount of the iris wing 25
And a driver 23. The illumination light that has passed through the condenser lens and the diaphragm enters the incident end surface of the light guide 11.

The dimming signal is transmitted to the iris driver 23. From the iris driver 23,
A motor control signal is sent to the motor 24 that opens and closes the iris blade 25, and the iris blade 25 of the aperture opens and closes.
The light amount of the illumination light from the light distribution lamp that enters the light guide 11 is adjusted.

In the photometry mode selector switch 22,
When the contact a side is selected, the average photometry circuit 17 performs average photometry. On the other hand, when the contact b side is selected by the photometry method changeover switch 22, the bottom photometry circuit 18 performs bottom photometry. The dimming signal obtained by the bottom photometry is a signal for controlling so that the darkest part of the image is always output with proper brightness.

The average photometry circuit 17 and the bottom photometry circuit 1
8 is a synchronizing signal generating circuit 30 to which a synchronizing signal generated at a predetermined timing based on the timing generator 19 is input. The average photometry circuit 17 and the bottom photometry circuit 18 perform photometry at a timing synchronized with the synchronization signal.

FIG. 1 shows the details of the bottom photometry circuit 18. An example will be described in which the luminance signal Y as shown in FIG. 5A is input to the circuit of FIG. The bottom photometry circuit 18 includes an inverting circuit 44 that inverts a luminance signal.
A bottom hold unit 31 for detecting and holding the peak value of the inverted luminance signal, that is, the bottom value of the luminance signal, and a sample for holding the bottom value detected by the bottom holding unit 31. The bottom hold pulse, the bottom hold pulse, and the sample hold section 32
And a control pulse generator 33 that outputs a sample hold pulse.

The luminance signal Y is inverted by the inverting circuit 44 to become the signal YR as shown in FIG. 5B, and the darkest bottom value of the luminance signal Y is the peak value of the signal YR, that is, the original bottom. The value is the bottom hold section 31.
Is input to.

The inverted luminance signal YR is the bottom
It is input to the bottom detection diode 35 and the first analog switch 36 via the buffer 34 of the hold unit 31. The bottom detecting diode 35 is connected in parallel with the input / output terminal of the analog switch 36. The cathode of the diode 35 is grounded via a bottom-holding capacitor 37 and the buffer 3
A second part of the sample and hold section 32 via
Is input to the analog switch 39. Buffer 3
Reference numeral 8 is for increasing the input impedance so as not to decrease the voltage of the capacitor 37.

At the control end of the analog switch 39,
A sample and hold pulse PS from a first one-shot multi-vibrator (hereinafter abbreviated as one-shot multi) 42 constituting the control pulse generator 33 is applied, and the first analog switch 36 has The bottom hold pulse PB from the second one-shot multi 43 is applied to the control end. The first one-shot multi 42 generates the sample-hold pulse PS according to the input synchronization signal, and the second one-shot multi 42
The one-shot multi 43 generates a bottom hold pulse PB by the sample hold pulse PS so as to follow the pulse PS.

The first analog switch 36 outputs the bottom hold pulse P from the one-shot multi 43.
When B is applied, the output terminal becomes conductive and the capacitor 3
The bottom value held at 7 is discharged and lowered. Until this pulse PB is not applied and the next pulse PB is applied, the analog switch 36
The signal is turned off and the peak (original bottom value) is detected by the diode 35, and the signal is held in the capacitor 37.

The second analog switch is also turned on between its input and output ends by the sample and hold pulse from the one-shot multi 42, and is held in the capacitor 40 via the buffer 38 and the capacitor 37. This pulse P is charged up to the peak (bottom) level.
After S is applied, the held bottom value is maintained until the next pulse PS.

The operation of the first embodiment thus constructed will be described below. The insertion section 5 of the electronic endoscope 1 is inserted into the living body, and, for example, the inside of the branched lumen of the bronchus is observed.

The subject region in the observation visual field including the illuminated bronchus is imaged on the CCD 10, read out by a signal from the driver 12, and input to the luminance signal processing unit 14 via the CDS 13. The luminance signal Y shown in FIG. 5A generated by the luminance signal processing unit 14 is inverted by the inverting circuit 44, and the signal Y shown in FIG.
R, which is the darkest bottom value of the luminance signal Y, is input to the diode 35 as the peak value of the signal YR.

The analog switch 36 connected in parallel to the diode 35 is connected to the analog switch 36 in parallel with the synchronizing signal from the one-shot multi 43 to the bottom hold.
While the pulse PB is being applied, it is in the on state, and is in the off state until the next pulse PB is applied.

The peak value of this constant period is the capacitor 37.
Is held in the buffer 38, and the voltage in the buffer 38 has a waveform as shown in FIG. That is, if there is a peak value (original bottom value), the waveform holds the peak value.

Immediately before the analog switch 36 is turned on, the peak value output from the buffer 38 is the peak value output from the buffer 38 by the sample and hold pulse PS shown in FIG. As shown in FIG. 5F, the buffer 41 holds the bottom value of the input (luminance) signal.

As shown in FIG. 4, this dimming signal is input to the iris driver 23 in the light source device 2, and the iris blade 25 of the diaphragm is moved by an amount corresponding to the dimming signal level based on the bottom value. It is opened and closed to adjust the amount of illumination light from the light distribution lamp. The larger the dimming signal, the more the iris blade of the diaphragm is opened to increase the amount of illumination light.

By this adjustment, the light is automatically adjusted so that the darkest portion in the visual field observation, in this case, the interior of the branched lumen of the bronchus, has an appropriate illumination level. For example, in the case of average photometry, as shown in FIG. 6 (a), the inner part of the lumen of the bronchus is dark and cannot be observed, but in bottom photometry of this embodiment, as shown in FIG. 6 (b), The darkest part inside the lumen can be kept at an appropriate brightness. As a result, it is possible to eliminate the oversight of lesions and the like that were dark and could not be seen, such as the inner part of the branch of the bronchus.

FIG. 7 relates to a second embodiment of the present invention, and FIG. 7 is an electrical block diagram of a signal processing device. The endoscope apparatus of the present embodiment is replaced with the signal processing device 3 of the first embodiment,
The signal processing device 3A shown in FIG. 7 is provided. In addition to the average photometry and the bottom photometry of the first embodiment, this signal processing device 3A can selectively perform peak photometry. Other configurations and operations similar to those of the first embodiment are designated by the same reference numerals and description thereof will be omitted.

The signal processing device 3A is provided with a bottom / peak photometric circuit 45 which also serves as a peak photometric circuit, in addition to the bottom photometric circuit 18 of the first embodiment.

Luminance signal Y from the luminance signal processing section 14
Is input to the photometric method selection switch 47. The photometric method changeover switch 47 has a contact point c in addition to the photometric method changeover switch 22 of the first embodiment, and this contact point c is connected to the bottom / peak hold section 31 of the bottom / peak photometry circuit 45. There is. The bottom / peak hold unit 31 has the same structure as the bottom / hold unit 31 of the first embodiment, and the control pulse generation unit 33.
Then, the bottom / peak hold pulse PB / PP is input. This bottom / peak hold pulse PB
/ PP is the same as the bottom hold pulse PB.

Further, the signal processing device 3A has a photometric signal adjusting circuit 46 for operating the operation of the iris blade 25 of the light source device 2 in the opposite direction to that in the bottom photometry during peak photometry.
And a dimming signal changeover switch 48 interlocking with the photometric method changeover switch 47. The switching of the photometric method changeover switch 47 and the dimming signal changeover switch 48 is controlled by the CPU 21.

With this configuration, at the time of bottom photometry, the photometric system changeover switch 47 and the dimming signal changeover switch 48
Then, by selecting the contact b, the same action and effect as in the first embodiment can be obtained.

Further, peak light metering is performed by selecting the contact c with the light metering method changeover switch 47 and the dimming signal changeover switch 48. However, in this light metering method, the luminance signal inversion circuit 44 does not pass, and normally, Luminance signal Y
Is input to the bottom / peak hold unit 31. Therefore, the bottom / peak hold unit 31 detects the brightest peak value and holds it in the sample hold unit 32. However, while the dimming signal obtained here is the same as the dimming signal at the time of the bottom photometry, the iris driver 23 in the subsequent stage is set so that the larger the value, the more the aperture is opened. On the contrary, in the case of peak photometry, it is necessary to change the signal so that the larger the value, the more the aperture closes, and the signal conversion processing is performed by the photometric signal adjusting circuit 46.

According to the present embodiment, the peak metering and the bottom metering can be easily switched, and not only the optimum image can be selected at all times, but the circuit structures of the peak metering and the bottom metering are almost common. Easy to do,
It can be a compact device.

In order to adjust the brightness, the illumination light amount is not limited to the variable one as in this embodiment, but the illumination light amount is kept constant and the video signal side is adjusted by the AGC circuit (auto gain control circuit). May be adjusted. Also,
Both the illumination light amount and the video signal may be adjusted.

Further, not only for medical use but also for industrial endoscopes. Further, in each of the above-described embodiments, since there are many halation portions during bottom photometry and eyes are tired, a limiter may be provided on the video signal side so as to reduce the gain of the luminance signal above a certain level during bottom photometry. good.

[0042]

According to the endoscope apparatus of the present invention, even a dark portion such as the back of a branch of a bronchus is illuminated with appropriate brightness so that it can be observed in detail, so that a lesion or the like can be overlooked. The effect is that it can be prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a specific configuration example of a bottom photometry circuit according to a first embodiment.

FIG. 2 is an overall configuration diagram of an endoscope device.

FIG. 3 is a cross-sectional view of the distal end portion of the endoscope.

FIG. 4 is a block diagram of an endoscope device.

5 is a waveform diagram for explaining the operation of the circuit shown in FIG.

FIG. 6 is an explanatory diagram showing an effect of the present endoscope apparatus.

FIG. 7 is an electrical block diagram of a signal processing device according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope 2 ... Light source device 3 ... Signal processing device 4 ... Monitor 18 ... Bottom photometric circuit 23 ... Iris driver 24 ... Motor 25 ... Iris blade 31 ... Bottom hold part 32 ... Sample hold part 33 ... Control signal Pulse generator 44 ... Inversion circuit 60 ... Endoscope device

Claims (1)

[Claims] 1. An endoscope apparatus having an illuminating device for an object, which processes an output from an image pickup device to output a video signal, the detection detecting a brightness level of a low brightness portion obtained from the video signal. An endoscope apparatus comprising: a means and a means for controlling an illumination light amount of the illumination means according to an output of the detection means.