JPH02308116A - Electronic endoscopic device - Google Patents

Abstract

PURPOSE:To prevent an object image from getting dark in the case of displaying it on a monitor by providing a means for inhibiting an image pickup signal from being inputted in a photometry means for obtaining a brightness mean value at an image pickup level from the image pickup signal in the duration of a signal at high brightness level. CONSTITUTION:Image signals read out from a CCD 28 are inputted in photome try circuits 35 and 36 respectively and integrated to generate a signal for control ling an illuminating light quantity and a signal for controlling a signal level at an appropriate one, which are outputted to a diaphragm control circuit 24 and an AGC circuit 33 so as to control the stop quantity of the diaphragm 25 and the gain of the AGC. An S.BLK pulse from a treatment tool blanking (S.BLK) pulse generation circuit 37 is inputted in the respective photometry circuits 35 and 36. When the S.BLK pulse is inputted, the photometry circuits 35 and 36 inhibit the image signal from being inputted in the duration of the signal. The illuminating light quantity to an object 26 is prevented from deviat ing from an appropriate value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electronic endoscopy a5A device equipped with photometric means.

[Prior art] In recent years, instead of fiberscopes for observing optical images transmitted by image guides with the naked eye, solid-state imaging devices such as charge-coupled devices (CODs) have been installed, and video signals obtained from this solid-state imaging device are used for color monitors. An electronic endoscope device that displays information on a screen has been put into practical use.

Currently, the electronic endoscope device described above has a narrower dynamic range than the direct observation with the naked eye using a fiberscope, so it has a dimming function that sets the illumination light to an appropriate level to obtain images that are easy to diagnose or observe. It is equipped with the following.

FIG. 11 shows a conventional electronic endoscope device 91. As shown in FIG.

The electronic endoscope rA92 is connected to a video processor (main unit) 93, and is supplied with illumination light from a light source section 94. That is, the illumination light from the light source lamp 95 passes through the aperture 97 controlled by the aperture control circuit 96 and then passes through the light guide 98.
supplied to The light is transmitted by the light guide 98 and emitted from the tip end toward the subject 99 .

The illuminated object 99 is imaged by an objective lens 101 on an image sensor 102 disposed on its focal plane, photoelectrically converted into an image signal, and input to an AGC circuit 104 via a signal cable 103. The AGC circuit 104 changes the gain of its output signal according to the level of the input signal, converts the signal into a signal with an appropriate amplitude, and sends the signal to the signal processing circuit 105. This signal processing circuit 105 converts the signal into a standard television signal, and displays the subject image in color on a color monitor 106.

Further, the image signal of the image carrying means 102 is transmitted to the aperture control circuit 9.
6, and controls the light amount of the aperture 97 according to the level of the image signal.

For example, when the amount of incident light is small, such as when the subject 99 is far away or when the reflectance of the subject 99 is low,
Reduce the aperture 970 aperture or fully open it. On the other hand, if the subject 99 is nearby and the amount of incident light is too large, the aperture 97 is adjusted to an appropriate amount of illumination light.

Further, the AGC circuit 104 functions to assist the dimming function of the aperture 97.

For example, if the subject 99 is far away and the amount of illumination light is insufficient even when the aperture 97 is fully opened, and the amount of light incident on the m-image element 102 is not the appropriate amount, the gain for amplifying the image signal is increased to obtain an appropriate image. Set the signal level to display an image that is easy to diagnose or observe.

In a medical endoscope, a treatment instrument insertion channel 107 is provided so that, for example, the inside of the stomach wall can be stained or a contrast agent can be injected. 108 may be protruded from the tip of the endoscope to perform the above-mentioned treatment.

In this case, the treatment tool 108 is often made of white Teflon or gold phoenix, and the objective lens 101 is smaller than the object 99.
Since the object enters the field at a position close to , the amount of incident light is much higher in some parts than in other parts.

The image appears on the monitor 106 as shown in FIG. That is, in the endoscopic image display image 1i109, the treatment instrument image 108 is placed on the subject image (indicated by the same number as the subject) 99.
is displayed. The signal level of the image signal GS in this case is as shown in FIG. 13, and when this screen 109 is scanned in the horizontal (horizontal) direction, the signal level portion corresponding to the treatment instrument image 108 is as shown by reference numeral 108'. The level becomes extremely high, and there is a large difference from the average signal level Va of the other image signals GS, which should be in a proper state.

[Problems to be Solved by the Invention] In the conventional example described above, the display level of the subject image 99 is controlled by the signal shown in FIG. deviates from the appropriate level.

By the way, the photometry circuit that operates the aperture control section or AGC can be roughly divided into average photometry and peak photometry.

In peak photometry, the maximum value of the image signal is always controlled to an appropriate level, so in the example of the treatment instrument 108, the peak 111108' in FIG. The image signal level becomes much lower than the appropriate level, making observation and diagnosis difficult.

On the other hand, in average value photometry, the average value of the signal level of the entire display screen 109 is optimized, but in the case shown in FIG. When the level of the value 108' is too high, the average level increases due to the influence of the treatment instrument 108, and in order to correct this, the signal level of the subject 99 is reduced. Therefore, observation and diagnosis of the subject 99 may be hindered.

In addition, in Japanese Patent Application Laid-open No. 62-110369, the imaging signal level of the central part and the surrounding parts is detected, and the gain of the imaging signal in each part is controlled to maintain the signal level of the central part even in the light transmission state. Discloses an imaging device that optimizes. In this publication, since the two regions in which the gain is changed are fixed, it is not possible to obtain desired results even when applied to the above-mentioned conventional example.

The present invention has been made in view of the above-mentioned points, and even if an object with a very high brightness level such as a treatment tool or other object with high reflectance protrudes into the observation field of view during observation of the subject, An object of the present invention is to provide an electronic endoscope device that can illuminate or display a subject at an appropriate level.

[Means and effects for solving the problems] The present invention provides an electronic endoscope equipped with a treatment instrument channel.
During a period of a high brightness level signal from a treatment instrument or the like in an image signal output from the image means, the image signal is inputted to a photometry means that calculates the average brightness value of the imaging level from the image signal. By providing a means for prohibiting this, it is possible to eliminate the possibility that the high brightness level of a treatment instrument or the like could cause the illumination light to fall on other parts of the subject that are originally intended to be observed, or that the subject image becomes dark when displayed on a monitor. There is. [Example] The present invention will be specifically described below with reference to the drawings.

Figures 1 to 6 relate to the first embodiment of the present invention.
FIG. 2 is a block diagram showing the configuration of the electronic endoscope device of the first embodiment, FIG. 2 is a perspective view showing the external appearance of the first embodiment, and FIG. 3 is a circuit diagram showing the configuration of the scope detection circuit, etc. Fig. 4 is a circuit diagram showing the photometry circuit, Fig. 5 is an explanatory diagram showing how the treatment instrument appears on the endoscope display screen, and Fig. 6 is a treatment instrument blanking pulse generated during the image signal period representing the treatment instrument. FIG.

As shown in FIGS. 1 and 2, the electronic endoscope device 1 of the first embodiment includes an electronic endoscope 2 having a built-in imaging means, and a light source unit that supplies illumination light to the electronic endoscope 112. (See FIG. 1) The video processor 5 includes a built-in video processor 3 and a signal processing section 4, and a color monitor 6 that displays a standard video signal output from the video processor 5.

As shown in FIG. 2, the electronic internal pA mirror 2 has an elongated, for example, flexible insertion section 7, and a large diameter operating section 8 is connected to the rear end of the insertion section 7. A flexible cable 9 extends laterally from the operating portion 8, and a connector 11 is provided at the tip of the cable 9. This electronic endoscope M2 can be connected to the video processor 5 via the connector 11.

On the distal end side of the insertion section 7, there is a hard distal end section 12, and on the rear side adjacent to this distal end section 12, there is a bendable curved section 13.
are set up in sequence. Further, by rotating a bending operation knob 14 provided on the operating section 8, the bending section 13 can be bent in the left-right direction or the up-down direction. Further, the operating section 8 is provided with an insertion port 16 that communicates with a treatment instrument channel 15 provided in the insertion section 7.

As shown in FIG. 1, a light guide 21 for transmitting illumination light is inserted into the insertion section 7 of the electronic endoscope &lt2. This light guide 21 is connected to the cable 9 shown in FIG.
By passing through the light guide 21 and connecting it to the video processor 5, white illumination light is supplied from the light source section 3 to the end surface of the light guide 21 on the incident side.

A lamp 2 that emits light by power supplied from a power source 22
The illumination light No. 3 passes through the aperture 25 whose aperture amount is controlled by the aperture control circuit 24 and is irradiated onto the end surface of the light guide 21 .

The light is transmitted by the light guide 21 and emitted from the emission end face on the distal end side of the insertion section 7 toward the subject 26 in front.

The illuminated object 26 is imaged by the objective lens 27 attached to the tip 12 on the imaging surface of the C0D 28 as a solid-state imaging device disposed at its focal plane, and photoelectrically converted.

A mosaic filter 29 is attached to the image plane of this C0D 28 to separate colors for each pixel.

A drive signal from the drive circuit 31 in the video processor 5 is applied to the C0D 28 through the signal cable 31. By applying this drive signal, the signal charge is read out, and this image signal is transmitted through the signal cable 32. and is input to the AGC circuit 33. This AGC circuit 33 performs automatic gain control according to the magnitude of the signal level, and the signal processing circuit 34 converts it into a standard video signal.
The subject image is displayed in color on the color monitor 6.

The image signals read out from the C0D28 are respectively input to the photometry circuits 35 and 36, which integrate the image signals to generate a signal for adjusting the illumination light amount and a signal for controlling the signal level to an appropriate signal level, respectively. lll
l11 circuit 24. Output to AGC circuit 33, comparison 25
Controls the aperture distance and AGC gain.

By the way, each of the photometry circuits 35 and 36 receives S from the treatment tool blanking (abbreviated as S, BLK) pulse generation circuit 27.
, BLK pulses are input.

When the S and BLK pulses are input, the photometry circuit 35.
36 prohibits input of the image signal during that signal period. A scope discrimination signal from the scope detection circuit 38 is input to this S, BLK pulse generation circuit 37, and outputs S, BLK pulses according to this scope discrimination signal.

That is, the position of the treatment instrument 39 that protrudes into the endoscope screen differs depending on the type of electronic device 112 used, but once the type is specified, the range (area) in which the treatment instrument 39 appears (projects) is almost decided.

Therefore, in this first embodiment, the type of electronic endoscope 2 used is determined by the type signal generating port 41 provided in the electronic endoscope 2.
The scope detection circuit 38 identifies the electronic endoscopy ff12 by the type signal from S.

The BLK pulse generation circuit 37 is configured to generate in advance a BLK pulse S, which masks a range (area) where the treatment instrument 39 is expected to protrude into the endoscope screen when the electronic endoscope 2 is used. ing.

The type signal generation circuit 41, the scope detection circuit 38,
The configuration of the S, BLK pulse generation circuit 37 is shown in FIG.

The type signal generation circuit 41 is inserted into the signal bin of the connector, for example, in the electronics. A resistor 42 having a resistance value corresponding to the type (kind) of 31112 is connected.

Further, the scope detection circuit 38 connects one of the bins (receivers) to which the above-mentioned bins are connected to, for example, 5V, and the other to the non-inverting input terminals of the comparators 43 and 44, and also connects them to ground via the resistor 45.

Each comparator 43, 44 has a different reference voltage V1. V2 is applied.

The above voltage V1. V2 depends on the value of resistor 42, Al7)
The potential Va is Va Vl > V2. Vl > Va > V
2. Vl>V2>Va can be satisfied, and the outputs of the comparators 43 and 44 at that time can be used as scope discrimination signals.

The outputs of the comparators 43 and 44 are applied to the address terminals AI and A2 of the ROM 4°6, for example, which constitute the S and BLK pulse generation circuit 37. An address clock synchronized with the synchronization signal is applied to other address terminals of this ROM 46.

However, terminal A1. H” or “shi” applied to A2
By combining the levels of
S, BLK that becomes “H” in the treatment instrument area that appears on one screen
It is designed to output pulses.

The above S and BLK pulses are generated by the photometry circuit 35 (
or 36) to generate a dimming signal (photometry signal). The input signal passes through a switch 48, an integrating circuit 49 formed by a resistor R and a capacitor C for determining the average luminance value, and is outputted from the output terminal. This switch 48 is S,
On/off is controlled by BLK pulse. In other words, S,
It is turned on during the period when the BLK pulse is not output (“L”), and turned off during the period when the BLK pulse is not output (“H”).

Therefore, photometry using the imaging signal (image signal) is not performed during this 8.81 pulse output period.

Therefore, for example, if a certain type of electronic endoscope 2 is connected to the video processor 5, and a subject 26 is displayed on the color monitor 6 at an endoscope screen angle of 5° as shown in FIG. When the treatment instrument 39 is used with the endoscope 2 and its tip is protruded from the tip of the channel 15 toward the subject 26, the treatment instrument 39 will be displayed on the screen as shown in this figure, depending on the arrangement structure of the electronic endoscope 1m2. It appears in the image (within the field of view) from a substantially fixed position within 5o.

On the other hand, the type of electronic congratulation 122 is detected by the scope detection circuit 38, and further by the S and BLK pulse generation circuit 37.
Accordingly, the S and BLK pulses are generated in an area 51 (indicated by a dotted line) where the treatment instrument 39 in FIG. 5 is expected to appear on the screen.

In other words, in one horizontal period of the image signal from the C0D 28, a high-intensity signal level 39 portion due to the treatment tool 39 appears in the signal portion corresponding to the subject 26 as shown in FIG. 6(a); The same figure (
As shown in b), S and BLK pulses are output.

For this reason, the photometry circuits 35 and 36 are prohibited from performing photometry on the image signal at this GKi degree signal level 39' portion, so they do not photometer this high ff1 degree signal level 39'. By storing the camera in a
It is possible to prevent the gain of 3 from being suppressed too much.

Therefore, according to the first embodiment, the amount of illumination light can be automatically controlled so that the amount of incident light from the subject 26 is at an appropriate level. Therefore, even if the treatment tool 39 is used and the treatment tool 39 appears within the field of view, the amount of illumination light to the subject 26 may deviate from the appropriate value due to the high brightness level of the treatment tool 39. There is almost no phlegm, and it is easy to observe or diagnose. Also, the AGC circuit 33
The gain is also hardly affected by the treatment instrument 39, and can be maintained at a brightness that is easy to see.

Note that a sample-hold means for sampling and holding the output of the integrating circuit 49 every field/frame period may be provided after the integrating circuit 49, or a reset circuit may be provided for resetting the integrated value of the integrating circuit 49 after this sample-holding. good.

FIG. 7 shows a photometric circuit 61 in a second embodiment of the invention.

This second embodiment uses a switch 4 which is turned on/off by S and BLK pulses in a photometric circuit 35 or 36 shown in FIG.
8 is replaced by a switch 62 that switches between the input signal and the constant voltage Va.

This constant voltage (a) is set, for example, to the average level of the image signal under an appropriate amount of illumination.

In the switch 62, the contact a is turned on so that the input signal side is selected during the period when the S and BLK pulses are not output, and the contact a is turned on during the period when the S and BLK pulses are output, and the voltage va is integrated. It is arranged so that it is input to the circuit 49.

This second embodiment has the possibility of setting an appropriate amount of illumination light more accurately than the first embodiment.

FIG. 8 shows a photometric circuit 65 in a third embodiment of the present invention.

This third embodiment has a photometric circuit 35 (or 3
6), the input signal is further input to the comparator 66 and compared with the reference voltage vb, and this comparison output is used as the S, BL
On/off of the switch 48 is controlled via an AND circuit 67 which opens and closes the gate in response to the K pulse.

This photometry circuit 65, during the S and BLK pulse periods,
When the image signal level is above a predetermined value, the switch 48
is turned off so that no integral operation is performed.

That is, as shown in FIG. 6, the output width t of the S, BLK pulse is generally set larger than the signal period t' of the treatment instrument 39, so if the integral operation is simply stopped during the S, BLK pulse period t1, t- In this embodiment, this S
, during the BLK pulse period t, the relatively high 1r4Ir
It is determined whether the voltage exceeds the voltage Vb (an example of which level is shown in FIG. 6(a)) which is considered to be fi, and if the voltage is higher than this voltage vb, the integral operation is stopped, and if By performing an integral operation, more accurate photometry or light control than in the first embodiment is achieved. Although this third embodiment is an improvement over the first embodiment, it can also be applied to the second embodiment shown in FIG.

FIG. 9 shows a photometric circuit 71 according to a fourth embodiment of the present invention.

This embodiment does not use the type signal generation circuit 41, scope detection circuit 38, S, BLK pulse generation circuit 37, and when a high brightness level of an image signal is detected, the high brightness level is determined to be a high brightness level caused by a treatment instrument, etc. Then, during that signal period, the signal is not used for photometry (in this embodiment, the voltage is switched to the voltage ya described above).

Similar to that shown in FIG. 7, the input signal is input to the integrating circuit 49 via the switch 62. Also, this input signal is input to a comparator 66 in the same manner as shown in FIG. 8, and is compared with the voltage vb corresponding to the high brightness level, and the comparison output is used to control the switching of the switch 62 through an OR circuit 72. I have to.

Further, the output of the integrating circuit 49 is connected to AG via the switch 73.
It is output as a C control signal. This switch 73 is similarly switched to the switch 62 by the output of the OR circuit 72.

The voltage VC in this case is set to a voltage value that sufficiently lowers the gain of the AGC circuit 33.

Note that the diaphragm control circuit 24 is configured to perform the diaphragm uIt[l operation using the output of the integrating circuit 49 without going through the switch 73.

That is, in this embodiment, the two photometric circuits 35 and 36 in FIG. 1 are not used, but one photometric circuit 71 is used.

In addition, if it is not desired to switch the switches 62 and 73, the output of the OR circuit 72 can be always set to "HIT" by turning on the switch 74.
It can also be used when trying to observe parts of treatment tools, etc. to some extent.

By the way, by switching the switch 73, the AGC circuit 33
The reason why the gain can be made small is as follows. If the treatment instrument 39 is displayed with high brightness as it is, the parts near it will be relatively dark and difficult to see. Therefore, in order to avoid this, if it is determined that the area is at a high brightness level, the level of the signal is sufficiently lowered to display the vicinity of the high brightness level part in an easy-to-see state. Note that the AGC circuit 33 in this case is desirably one that responds relatively quickly to the voltage level applied to the AGC terminal.

Further, for example, an attenuator may be provided in parallel with the AGC circuit 33, and when the switch 73 is switched, a signal may be outputted to the signal processing circuit 34 side through the attenuator.

Note that different embodiments may be constructed by partially combining the embodiments described above.

FIG. 10 shows an electronic endoscope device according to the fifth embodiment of the present invention! 7
5 is shown.

This device 75 uses a fiber scope 76 and a television camera 77 instead of the electronic camera 112 in the device 1 shown in FIG.

The fiberscope 76 is the same as the electronic endoscope 2 shown in FIG. 2, except that an eyepiece 78 is provided on the top side of the operating section 8 so that a television camera 77 can be attached thereto. or,
The internal configuration of the electronic endoscope 12 shown in FIG.
One end of an image guide 79 is disposed on the focal plane of the objective lens 27, and transmits an optical image to the other end face disposed on the eyepiece 78 side. An eyepiece lens 81 is disposed opposite to this end surface, allowing observation with the naked eye. Also, the television camera 77 is
An imaging lens 82 is disposed opposite the eyepiece 81, and a mosaic filter 83 is attached to the imaging position.
D84 is installed. A type signal generating circuit 87 is housed in a connector 86 at the tip of the cable 85 of the television camera 77. This circuit 87 can select a plurality of resistances using a switch S, and generates a signal representing the type corresponding to the structure of the fiberscope 76 used, that is, the observation optical system, the treatment instrument channel 15, the direction of the camera 77 attached, etc. I'm trying to make it possible.

On the other hand, in the video processor 5 shown in FIG.
The configuration is such that the AGC circuit 33 and the aperture control circuit 24 are controlled by the output of 5.

The rest is the same as the first embodiment.

It is clear that other embodiments can be used as the photometric circuit 35.

In the above description, an apparatus that performs color imaging under white illumination has been described, but the present invention is not limited to this, but can also be applied to a frame sequential type apparatus.

[Effects of the Invention] As described above, according to the present invention, when a high 711 degree signal level portion exists in an imaging signal by a device constituted by a channel, the photometry means does not operate during the high signal level period. Since input is prohibited, it is possible to prevent the illumination light from deviating from an appropriate value due to a high AM signal level.

[Brief explanation of drawings]

Figures 1 to 6 relate to the first embodiment of the present invention.
FIG. 2 is a block diagram showing the configuration of the electronic endoscope device of the first embodiment, FIG. 2 is a perspective view showing the external appearance of the first embodiment, and FIG. 3 is a circuit diagram showing the configuration of the scope detection circuit, etc. Fig. 4 is a circuit diagram showing the photometry circuit, Fig. 5 is an explanatory diagram showing how the treatment instrument appears on the endoscope display screen, and Fig. 6 is a treatment instrument blanking pulse generated during the image signal period representing the treatment instrument. 7 is a circuit diagram of a photometric circuit in a second embodiment of the present invention, FIG. 8 is a circuit diagram of a photometric circuit in a third embodiment of the present invention, and FIG. 9 is a circuit diagram of a photometric circuit in a third embodiment of the present invention. The circuit diagram of the fourth embodiment, FIG. 10 is a block diagram showing the configuration of the fifth embodiment of the present invention, FIG. 11 is a block diagram showing the conventional example, and FIG. 12 shows the treatment instrument displayed on the endoscope display screen. FIG. 13 is a waveform diagram showing the image signal in the case of FIG. 12. 1...Electronic endoscope device 2...Electronic endoscope 3...
・Light source section 4...Signal processing section 5...Video processor 6...Color monitor 15...Channel 23...Light source lamp 24...Aperture control circuit 25...Aperture 28...CCD 3
5, 36...Photometry circuit 37...S, BLK pulse generation circuit 38...Scope detection circuit 39...Treatment tool 41...Type signal generation circuit Figure 2, Figure 3, Figure 4, S, BLK pulse Figure 5 Figure 6 Figure 7 Figure 9 @ Figure 8

Claims (1)

[Claims] An electronic endoscope equipped with an imaging means and a treatment instrument insertion channel, and a pulse signal is generated in a predefined area where the treatment instrument projected through the channel can protrude into an imaging region by the imaging means. a photometric device that calculates an average brightness value from an output signal of the imaging device; and a device that prohibits the output signal of the imaging device from being input to the photometric device during the generation period of the pulse signal. An electronic endoscope device characterized by: