Endoscope apparatus

Abstract: An endoscope having at the tip of its inserting section a detecting device (22) for detecting physical or chemical changes allows transmission of signals from the detecting device (22) without requiring a dedicated signal line for this detecting device. For example, an electronic endoscope apparatus (1) of the type which has an inserting section extending from an operating section, includes: a detecting device (22) for detecting physical and chemical changes, such as a humidity sensor or a gas sensor, provided at a tip of the inserting section; a notifying device for notifying of the detection results of the detecting device (22) by, for example, displaying them through a monitor; an image-sensing device (17), such as a CCD, provided at the tip of the inserting section; and a signal line (18, 23) consisting, for example, of a coaxial cable, connected to the image-sensing device (17); wherein signals from the detecting device (22) are transmitted through a transmission line (23h), e.g., an armoring line, which is among the transmission lines provided in the signal line (18, 23) and which is not being used in the transmission of signals from the image-sensing device (17). With this construction, an increase in the diameter of the endoscope inserting section can be avoided in spite of the provision of the detecting device (22).

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an endoscope apparatus having at the tip of its inserting section a detection means for detecting physical or chemical changes. 2. Related Art Statement In place of the fiber-type endoscope, which transmits optical images through an optical fiber, an electronic endoscope utilizing a photoelectric-conversion-type image sensor is beginning to find its way into the market, due to its multifunctional character. However, the electronic components inside such an electronic endoscope, including the image sensor, are rather sensitive to environmental conditions, such as temperature, humidity and disinfectant gas, so that when placed under any severe condition for a long period of time, the electronic components may become damaged irreparably. The flexible sheathing tube of an endoscope consists of a rubber tube having a bendable structure, so that it, particularly, is subject to generation of cracks or pinholes, through which water is likely enter. Also, when sterilizing the endoscope with a disinfectant gas, intrusion of gas may occur through these cracks or pinholes, resulting in the electronic components inside the electronic endoscope, in particular, the semiconductor devices, being damaged. Further, any cracks or pinholes may allow infectious, disease-causing organisms to get into the electronic endoscope during an operation; therefore, the endoscope cannot be sufficiently sterilized by washing in antiseptic solution alone, and there is the possibility of a second patient being infected with a disease. In view of this, Japanese Patent Laid-Open No. 1991-236825 and Japanese Utility Model Laid-Open No. 1985-37301 have proposed endoscope structures according to which a humidity sensor is provided inside the endoscope, thereby detecting any leakage of water into the endoscope. In the technical means described in Japanese Utility Model Laid-Open No. 1985-37301, in which any water leakage is detected by a humidity sensor provided in the tip section of the endoscope, the electronic components inside the electronic endoscope may become damaged to such a degree as to be irreparable by the time the sensor has detected the leakage. In view of this, the endoscope described in Japanese Patent Laid-Open No. 1991-236825 adopts a structure in which the electronic components mounted in the electronic endoscope are collectively arranged in a waterproof structure forming an image sensor unit, with the humidity sensor being arranged on the external surface of this image sensor unit. The humidity sensor is connected to a water-leakage detecting circuit inside an endoscope controller through a dedicated signal line for leakage detection, thereby making it possible to transmit a water-leakage detection signal before the electronic components have been damaged by water leakage. With this prior-art technique, any water leakage can be repaired before the electronic components have been damaged thereby, thus enabling the image sensing unit to be used again. However, the above-described prior-art technique has a problem in that the humidity detecting means is provided in the tip section of the endoscope, which means a dedicated signal line for humidity detection has to be separately provided. As a result, an increase in the diameter of the inserting section is inevitable as compared to that of an endoscope apparatus not equipped with such a humidity detecting means. Apart from this, Japanese Patent Laid-Open No. 1985-69620 discloses an endoscope having a solid-state image sensing device in the tip section thereof, according to which at least one network tube is formed by a plurality of conductors which constitute outlet paths for image signals obtained by this solid-state image sensing device and inlet paths for drive signals for driving the solid-state image sensing device, with a bundle of light-guide fibers, an air/water-supply channel, or a forceps channel being inserted into this network tube. Due to this construction, the tube diameter of the inserting section is reduced as compared to that type of endoscope in which a plurality of conductors are arranged as separate channels, by the space occupied by those channels. OBJECTS AND SUMMARY OF THE INVENTION A first object of this invention is to provide an endoscope apparatus which is capable of detecting physical or chemical changes and transmitting a relevant detection signal without requiring an augmentation in the diameter of the endoscope inserting section. A second object of this invention is to provide an endoscope apparatus which is capable of detecting physical or chemical changes, transmitting a relevant detection signal without requiring an augmentation in the diameter of the endoscope inserting section, and notifying of the detection result. A third object of this invention is to provide an endoscope apparatus which is capable of detecting the humidity at the tip of the endoscope inserting section, and transmitting a relevant detection signal to the side of the apparatus operating section without requiring an increase in the diameter of the inserting section. A fourth object of this invention is to provide an endoscope apparatus which can detect humidity in a reliable manner. A fifth object of this invention is to provide an endoscope apparatus which can notify about the condition of the humidity intrusion or degree of water leakage in the tip section of the endoscope. A sixth object of this invention is to provide an endoscope apparatus which can detect humidity reliably before the image sensing unit has suffered any damage by humidity or water leakage. A seventh object of this invention is to provide an endoscope apparatus which is capable of reliably detecting humidity no matter from which direction of the image sensing unit it has intruded. An eighth object of this invention is to provide an endoscope apparatus which can detect physical or chemical changes at the tip of the inserting section and transmit a relevant detection signal to the side of the apparatus operating section without allowing the signal to attenuate. A ninth object of this invention is to provide an endoscope apparatus which is capable of detecting at least one of the following: temperature, pressure, gas, vital reaction or magnetism. In the US-A-4 995 396 an electronic endoscope is disclosed not having the advantages as described in the objects for this invention. To put it briefly, this invention relates to an endoscope apparatus comprising: detecting means for detecting physical or chemical changes provided at the tip of an inserting section, excluding means for observing an object of inspection; and signal transmission means for transmitting signals from the detection means which also has functions other than that of transmitting the signals from the detection means. Advantages of the present invention as set forth in claim 1 will become further apparent from the following detailed explanation. BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1 through 5 show a first embodiment of the present invention, of which: Fig. 1 is a block diagram showing the overall construction of an endoscope apparatus; Fig. 2 is a block diagram showing the construction of an essential part of the electric circuit of the endoscope apparatus; Fig. 3 is a block diagram, partly consisting of a circuit diagram, showing in detail a humidity sensor and a water-leakage detecting circuit; Fig. 4 is a plan view showing an example of the humidity-sensor structure; and Fig. 5 is a sectional view showing another example of the humidity-sensor structure; Figs. 6 and 7 show a second embodiment of the present invention, of which: Fig. 6 is a block diagram, partly consisting of a circuit diagram, illustrating in detail a humidity sensor and a water-leakage detecting circuit; and Fig. 7 is a graph showing the relationship between humidity-sensor output and humidity; Fig. 8 is a perspective view showing a tip-section unit serving as the image sensing unit in a third embodiment of the present invention; Fig. 9 is an enlarged perspective view showing an SID (solid-state image sensing device) in a fourth embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of this invention will now be described with reference to the drawings. Figs. 1 through 5 show the first embodiment of this invention, of which Fig. 1 is a block diagram showing the overall construction of an endoscope apparatus; Fig. 2 is a block diagram showing the construction of an essential part of the electric circuit of the endoscope apparatus; Fig. 3 is a block diagram, partly consisting of a circuit diagram, showing in detail a humidity sensor and a water-leakage detecting circuit; Fig. 4 is a plan view showing an example of the humidity-sensor structure; and Fig. 5 is a sectional view showing another example of the humidity-sensor structure. As shown in Fig. 1, the main section of an endoscope apparatus 1 is composed of an endoscope 2, a light-source section 3 for supplying the endoscope 2 with illuminating light, an endoscope controller 5 containing a video-processing circuit 4 for signal processing, etc., and a monitor 6 for displaying an image of an object, etc. The endoscope 2 is composed of a long and narrow inserting section 7, an operating section 8 formed at the rear end of the inserting section 7, and a universal cord 9 extending outwardly from the operating section 8. Passed through the inserting section 7 and the universal cord 9 is a light guide 11 for transmitting light; by connecting a connector 12 attached to the end of the universal cord 9 to the endoscope controller 5, light is supplied form the light-source section 3. White light emitted from a lamp 13 is condensed by a condenser lens 14 and applied to the inlet-side end surface of the light guide 11. The light is then transmitted through the light guide 11 to a tip section 15 of the endoscope 2, where it is emitted from the outlet-side end surface of the light guide to illuminate an object in front. An optical image of the object being illuminated is formed on a solid-state image sensing device (hereinafter abbreviated as "SID") 17, such as a CCD, by an objective optical system 16 provided in the tip section 15, the SID 17 being arranged in the focal plane of this optical system. The SID 17 is covered with a leakage-proof member 21 provided inside the tip section 15. The optical image formed on the image-forming surface of the SID 17 is photoelectrically converted by the SID 17 into an electric signal, which is transmitted to the video-processing circuit 4 through an SID-output-signal transmission cable 18, which serves as a signal line. The SID 17 is connected to a driving circuit 10 through an SID drive cable 23 which serves as a signal line. In many cases, coaxial cables or shielded cables are employed for the SID-output-signal transmission cable 18 and for the SID drive cable 23 for the purposes of reducing unnecessary radiational noise from the cables, preventing circuit malfunction due to the influence of external noises, mitigating distortion of the transmission waveform, etc. The video-processing circuit 4 converts the electric signal into a standard video signal, which is transmitted through a superimposing circuit 19 and displayed as an object image on a screen display section 20 of the monitor 6. Arranged in the vicinity of the leakage-proof member 21 is a humidity sensor 22 for detecting water leakage, humidity, etc. on the outside of the leakage-proof member 21. The humidity sensor 22 is connected to a leakage detecting circuit 24 in the controller 5 through the SID drive cable 23, which passes through the inserting section 7 and the universal cord 9. Based on the output of the humidity sensor 22, the leakage detecting circuit 24 outputs a detection signal indicating whether any water has been detected. This detection signal is supplied to the superimposing circuit 19, where it is superimposed on the output signal from the video-processing circuit 4 and then supplied to the monitor 6; when some water has been detected, a comment: "LEAKAGE DETECTED" or the like is displayed at the bottom on the left-hand side of the display screen of the monitor 6, or a display means (not shown) which is provided in the controller 5 gives a warning display. The leakage detection may also be notified by generating a warning sound or by simultaneously generating a visual display like a monitor display and a warning sound. That portion of the circuit of Fig. 2 which is related to humidity detection will be described in detail with reference to Fig. 3. Any water or humidity which has entered the tip section of the endoscope 2 is adsorbed or condensed on the surface of the humidity sensor 22, thereby changing the resistance value of the humidity sensor. The humidity sensor 22 is connected in parallel to a capacitor 26 for removing noises, one end of which capacitor is connected to a shielded conductor which is among the cables constituting the SID drive cable 23 and which is not transmitting any signal, with the other end of the capacitor 26 being grounded. As shown in Fig. 3, the SID drive cable 23 is composed of a plurality of cables 23a, ......, 23g and 23h. The signals to be transmitted therethrough include an SID vertical drive signal, an SID horizontal drive signal, an SID power source signal, etc. The leakage detecting circuit 24 employs an AC power source 31 as its power source, to which is connected a resistor 32 for detecting the resistance value of the humidity sensor 22 through voltage division. Because of the high impedance of the resistance value of the humidity sensor 22, the point of measurement, x, exhibits a high impedance. However, the cables in the electronic endoscope have a long length of, for example, 3 to 7m and, in the case of medical applications, in particular, a peripheral apparatus constituting a disturbance source, such as a high-frequency knife, is used with the endoscope apparatus, so that when used under a high-impedance condition, the signal transmission line for the humidity sensor is influenced by disturbance noise, resulting in circuit malfunction. Thus, in the connecting section of the cable, it is necessary to effect impedance matching with respect to the characteristic impedance of the cable. In view of this, a capacitor 33 serving as a terminator means is connected. The above-mentioned point of measurement x is connected to a rectifier-type detection circuit 34, which is composed of a diode 38, a resistor 39, and a capacitor 40 one end of which is grounded. The signal level output from the rectifier-type detection circuit 34 is compared with a reference signal level 36 by means of a comparator 35 using an operation amplifier, etc., and a signal indicating whether humidity, etc. has been detected is supplied to the superimposing circuit 19. In this embodiment, a shielded conductor consisting of a coaxial cable is used as the transmission line for the signal from the humidity sensor 22. In the end portion of the line, the impedance condition is close to open circuit. Thus it is desirable to avoid using the SID-output-signal transmission cable, the SID-horizontal-drive-signal transmission cable, etc., of which the impedance matching is particularly important in terms of image quality, and use another cable instead as the signal line for the humidity sensor. The driving frequency of the vertical drive signal is 15.7 (kHz), which is lower than that of the horizontal drive signal, so that even without the capacitor 26 in the endoscope tip section 15, no bad influence is generated from the viewpoint of practical use due to the terminal capacity (approximately 1000 PF) inside the SID 17, such as the CCD. Next, examples of the structure of the humidity sensor 22 will be described with reference to Figs. 4 and 5. The humidity sensor shown in Fig. 4 includes an insulating substrate 51 made of polyimide, glass, ceramics, epoxy or the like, comb-like electrode patterns 52 and 53 arranged alternately on the insulating substrate 51, and a humidity-sensitive resistor coating 54 applied to these electrode patterns. The humidity-sensitive resistor coating 54 consists of a swellable high-molecular film containing a conductor material such as carbon particles or the like, and is adapted to vary the inter-electrode resistance value in accordance with the changes in the swelling condition at the time of moisture absorption and dehumidification. Even without the humidity-sensitive resistor coating 54, this humidity sensor provides a satisfactory sensitivity by increasing the pitch of the arrangement of the electrode patterns 52 and 53. The humidity sensor shown in Fig. 5 includes a porous substrate 56, which is made of a glass, a ceramic material or the like which contains a hygroscopic electrolyte such as lithium chloride, the porous substrate 56 being placed between electrodes 57 and 58. This humidity sensor is also capable of sensing changes in electric resistance caused by moisture absorption and dehumidification. With the first embodiment, described above, it is possible to transmit signals from a detection means provided in the tip section, such as a humidity sensor, to the side of the apparatus operating section without requiring an of increase the diameter of the endoscope inserting section, and to reliably notify the operator of the detection results obtained by the detection means. If, in the first embodiment, a temperature sensor, a pressure sensor, a gas sensor, a biosensor, a magnetometric sensor, a gravity sensor or the like is used instead of the humidity sensor, there is no need to provide a dedicated signal transmission line for such a sensor, so that the detection of physical or chemical changes by a detecting device can be effected without having to augment the diameter of the inserting section of the endoscope. In the following, the above-mentioned sensors will be described one by one. A pressure sensor generally consists of a resistance-wire strain gage or the like. The smaller the sectional area of a metal wire having resistance, or the longer the length thereof, the larger is the resistance value thereof. Thus, when the metal wire is elongated to change its sectional area and length by applying a tension thereto, its resistance value changes, whereby the tension or pressure applied thereto can be measured. The pressure sensor structure, however, is not limited to the one described above. A temperature sensor based, for example, on a resistance thermometer bulb utilizes the fact that the resistance value of a metal wire changes in accordance with the ambient temperature. A temperature sensor using a thermocouple detects a thermo-electromotive force at the interface between two different metals, which force changes in accordance with the ambient temperature. The construction of the temperature sensor, however, is not limited to these two types. As regards the magnetometric sensor, there is one type based on a magnetic resistor type and another type based on a Hall element. In the former, any change in the carrier movement between electrodes on either side of a semiconductor when an electric field is applied thereto is detected as a resistance value. The latter type also utilizes the carrier movement for detect resistance value. The construction of the magnetic sensor, however, is not restricted to these two types The gas sensor functions as follows: any gas molecules adsorbed on a semiconductor surface consisting of a metal oxide cause a change in electron concentration due to electron exchange between the gas molecules and the semiconductor. This change is extracted as a change in the value of electric resistance. The construction of the gas sensor, however, is not limited to the one described above. The biosensor has a functional film consisting of a biosubstance. When this functional film reacts with a particular chemical substance, heat is generated along with a change in ion concentration, which change is converted to an electric signal by one of the sensors described above. This biosensor is currently being used as a sensor for detecting vital reactions, for example, as an oxygen sensor or an immunity sensor utilizing antigen-antibody reactions. The construction of the biosensor, however, is not restricted to the type described above. The gravity sensor comprises a weight which is placed on a piezoelectric element formed of quartz or ceramics sandwiched between two electrodes. The sensor is adapted to convert a change in gravity to a change in voltage. Apart from its use as an acceleration sensor, this sensor can be used in the detection of an attitude of something in a static condition (i.e., whether it is set horizontal, vertical, reversed, etc.). It may be used, for example, in the attitude control of an endoscope. The construction of the gravity sensor, however, is not limited to the one described above. Figs. 6 and 7 show the second embodiment of the present invention, of which Fig. 6 is a block diagram, partly consisting of a circuit diagram, illustrating in detail a humidity sensor and a water-leakage detecting circuit; and Fig. 7 is a graph showing the relationship between humidity-sensor output and humidity. The second embodiment differs from the first one, described above, in the following point: The signal source for driving the humidity sensor is a DC power source 41. The humidity sensor output, obtained at the point of measurement x, is supplied to comparators 42, 43 and 44, where it is compared with different reference levels 45, 46 and 47. As a result, it is possible, as shown in Fig. 7, to distinguish the condition around the sensor between "normal", "high humidity", "condensation" and "submergence'. The detection signals from the comparators 42, 43 and 44 are displayed in a display section 48 which is different from the monitor 6 (see Fig. 6) and which is provided in the endoscope controller 5, giving a warning to the observer. High-accuracy discrimination is also possible when A/D converters are employed as comparators. Fig. 8 is a perspective view showing a tip-section unit 61 serving as the image-sensing unit of the third embodiment of the present invention. Here, a description of those components of the third embodiment which are the same as those of the first and second embodiments will be omitted, and only those points which differ from the first and second embodiments will be described. The tip-section unit 61 has a structure as shown in Fig. 8. That is, the SID 17 is electrically connected to substrates 62 and 63 through lead feet 17a protruding from that surface thereof which is on the opposite side of its image formation surface. A capacitor 64 and an IC 65, which serve to supply electric power to the SID 17, are arranged on that surface of the substrate 63 which faces the substrate 62. The IC 65 functions, for example, as a buffer for amplifying the output of the SID 17 and driving the cables, and as a generator of various bias voltages, such as the SUB voltage and the gate voltages to be supplied to the SID 17. The cables 18 and 23 are connected to the substrates 62 and 63. A humidity sensor 22 in the form of a long and narrow strip is wound around the above-described tip-section unit 61 at a fixed pitch. This humidity sensor 22 comprises a long and narrow bendable substrate, for example, a flexible substrate, and two long and narrow electrodes arranged close to each other on this substrate. It is not the comb-like type shown in Fig. 4 but has a parallel pattern in which the electrodes are closely arranged. It is based on the same detection principle as the one described above, detecting humidity from a change in impedance caused by any water adhering to the space between the electrodes. This third embodiment provides substantially the same effect as the ones described above and, further, makes it possible to detect water leakage into the tip-section unit 61 regardless of from what direction it has occurred, thereby improving the detection reliability. As in the above embodiments, it is more effective in this embodiment to cover the humidity sensor 22 with the above-described water-leakage proof member 21 before winding it around the tip-section unit 61. That way, it is possible to detect water leakage before the electronic components inside the unit 61 have been damaged by water intrusion. Fig. 9 is an enlarged perspective view showing an SID 17 according to the fourth embodiment of the present invention. Here, a description of those components of the fourth embodiments which are the same as in the first to third embodiments, described above, will be omitted, and only those points which differ from the other embodiments will be described. As shown in Fig. 9, the essential section of the SID 17 of the fourth embodiment is composed of a package 68 and a sensor chip 69 arranged thereon. The sensor chip 69 and the package 68 are electrically connected to each other by connecting electrical contacts 75 and 76, respectively provided on them, to each other through bonding wires 71. The output of this SID is emitted from a plurality of lead feet 17a protruding from that surface of the package 68 which is on the opposite side of the sensor chip 69. When the SID 17 consists, for example, of a CCD, the sensor chip 69 includes an image area 72 consisting of a plurality of photosensitive elements, such as photodiodes, arranged plain-like on the image forming surface, a horizontal CCD register 73 provided on one side of the image area 72, and an output amplifier 74 for voltage-converting photoelectric charge signals, with the plurality of electrical contacts 75 connecting to the above-mentioned bonding wires being arranged at one end of this sensor chip. In this embodiment, a sensor 22 for detecting humidity, etc. is integrally formed on the sensor chip 69, at a position, for example, near the output amplifier 74. The fourth embodiment, constructed as described above, provides substantially the same effect as the first to third embodiments. Further, since there is no need to form the detection means as a separate unit, the assembly process is simplified and the assembly time is reduced. Further, the present invention is not limited to the use of one type of sensor in an endoscope apparatus. It is of course also possible to construct an endoscope of substantially the same structure having a plurality of types of sensors. In this invention, it is apparent that a wide range of different working modes can be formed on the basis of this invention. This invention is not restricted by any specific embodiment except as it is limited by the appended claims.

Claims: An electronic endoscope apparatus which includes an inserting section (7) extending from an operating section (8), said electronic endoscope apparatus comprising: detecting means (22) for detecting physical and chemical changes provided at a tip of the inserting section (7); indicating means (6; 48) for indicating the detection results of said detecting means (22); image-sensing means (17) provided at the tip of said inserting section (7); a signal line (18, 23) connected to said image-sensing means (17); and a transmission line (23h) for transmitting signals from said detecting means (22), characterized in that said transmission line (23h) being a shielded conductor which is among the cables constituting the signal line (18, 23). An electronic endoscope apparatus according to claim 1, wherein said detecting means (22; 87) is a humidity detecting means. An electronic endoscope apparatus according to claim 2, wherein said humidity detecting (22) means includes: an insulating substrate (51); and two electrode patterns (52, 53) arranged close to each other on said insulating substrate (51). An electronic endoscope apparatus according to claim 3, wherein said two electrode patterns (52, 53) are formed alternately in a comb-like fashion. An electronic endoscope apparatus according to claim 3 or 4, wherein said two electrode patterns (52, 53) are covered with a moisture-sensitive resistor coating (54). An electronic endoscope apparatus according to claim 5, wherein said insulating substrate is in the form of a long and narrow strip, said electrode patterns being in the form of two substantially parallel lines arranged close to each other on said insulating substrate. An electronic endoscope apparatus according to claim 2, wherein said humidity detecting means (22) includes: a porous substrate (56) containing a hygroscopic electrolyte; and two electrodes (57, 58) between which said porous substrate (56) is interposed. An electronic endoscope apparatus according to claim 2, wherein said image-sensing means (17) is an image-sensing unit, said humidity detecting means (22, 94) being provided in the vicinity of this image-sensing unit. An electronic endoscope apparatus according to claim 8, wherein said humidity detecting means (22) is provided in the vicinity of said image-sensing unit (17) in such a way as to cover said image-sensing unit. An electronic endoscope apparatus according to claim 8, wherein said humidity detecting means (22) includes a bendable insulating substrate formed as a long and narrow strip, and electrode patterns in the form of two substantially parallel lines arranged close to each other on said insulating substrate, and is wound around said image-sensing unit (17, 62, 63) at a substantially fixed pitch. An electronic endoscope apparatus according to any of claims 1 to 10, wherein said indicating means consists of at least either a visual display means (6) or an auditory notifying means. An electronic endoscope apparatus according to any of claims 1 to 11, wherein said indicating means (48) gives a graduated display of the detecting condition of said humidity detecting means (22). An electronic endoscope apparatus according to claim 1, wherein said detecting means (22, 87) consists of one of the following means: a temperature detecting means, a pressure detecting means, a gas detecting means, a bio detecting means for detecting vital reactions as an oxygen sensor or an immunity sensor utilizing antigen-antibody reactions, a magnetic detecting means, or a gravity detecting means for converting the change in gravity to a change in voltage. An electronic endoscope apparatus according to any of claims 1 to 13, wherein said signal line (18, 23) is a shielded cable or a coaxial cable, said transmission line constituting a shielding line of said shielded cable or an armoring wire of said coaxial cable. An electronic endoscope apparatus according to claim 1, wherein said image-sensing means (17) is a solid-state image sensing device, said signal line constituting a vertical-drive-signal cable of said solid-state image sensing device (17). An electronic endoscope apparatus according to claim 1, wherein said transmission line (23) is connected to an AC-type terminator means (33). An electronic endoscope apparatus according to claim 1, wherein said detecting means (22) is provided integrally with said image-sensing means (17). An electronic endoscope apparatus according to claim 1, wherein said humidity detecting means (22) has two electrodes arranged close to each other. An electronic endoscope apparatus according to claim 1, wherein said indicating means (6; 48) is at least either a visual display means or an auditory notifying means.

Inventors: TSUJI KIYOSHI, TSUJI, KIYOSHI
Applicants: OLYMPUS OPTICAL CO, OLYMPUS OPTICAL CO., LTD.
Application year: 1993
Main classification: A61B1
IPC codes: G02B23, G08C23, A61B1