JP2013118937A - Electronic endoscope, method for manufacturing the same, and electronic endoscope system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To early detect whether moisture is penetrated into the tip of an endoscope insertion part without thickening the tip of the endoscope insertion part.SOLUTION: This electronic endoscope 12 includes a CMOS sensor 31 provided to the tip of the insertion part 16 inserted in a subject to internally image the subject, and a humidity sensor 104 for detecting the humidity of the atmosphere surrounding the CMOS sensor 31, and the CMOS sensor 31 and the humidity sensor 104 are integrally provided on the same semiconductor substrate 100. Further, the CMOS sensor 31 and the humidity sensor 104 are preferably formed by the same CMOS process.

Description

  The present invention relates to an electronic endoscope provided with a CMOS type image sensor at the tip of an insertion portion to be inserted into the body of a subject, a manufacturing method thereof, and an electronic endoscope system.

  Conventionally, examination using an endoscope, for example, an electronic endoscope, has been widely used in the medical field. An electronic endoscope includes an image sensor (solid-state imaging device) at the tip of an elongated insertion portion that is inserted into a subject, and is connected to a processor device (signal processing device) via a cord or a connector. The processor device performs various processes on the imaging signal output from the image sensor, and generates an image for diagnosis. The endoscopic image is displayed on a monitor connected to the processor device.

  As an image sensor mounted on an electronic endoscope, a CCD sensor has been generally used. Recently, various electronic endoscopes using a CMOS sensor have been proposed (for example, see Patent Document 1). The CMOS sensor can be driven at a lower voltage than the CCD sensor, and can easily meet the demands for a large number of pixels and high-speed reading. In addition, a CMOS process can be used in the manufacturing process, and peripheral circuits such as a drive circuit and a processing circuit can be mixedly mounted in the same chip, which is advantageous for downsizing.

  By the way, in an endoscope used for medical purposes, it is indispensable to surely disinfect and sterilize the used endoscope in order to prevent infection and the like. As a method for sterilizing an endoscope, a method using ethylene oxide gas (EOG) or a disinfectant is conventionally used, but in recent years, sterilization of an endoscope by autoclave sterilization (high-temperature high-pressure steam sterilization) is expected. Yes. Autoclave sterilization is a method of sterilization by exposing an object to be sterilized in steam at high pressure (about 120 ° C to 135 ° C) under high pressure, and it can be used immediately after sterilization without complicated work. In addition, there is an advantage that the running cost is low.

  In general, an endoscope employs an airtight or watertight structure in order to protect the internal components of the endoscope (see, for example, Patent Document 2). However, when performing autoclave sterilization, it is necessary to decompress the space in which the endoscope is housed in order to penetrate water vapor. At this time, there is a possibility that the outer skin of the curved portion expands and ruptures due to a pressure difference with the inside of the endoscope having a sealed structure.

  Therefore, it is possible to prevent such a situation by providing a communication structure capable of communicating / blocking the space inside and outside the endoscope near the connector part and gripping part of the endoscope, and performing autoclave sterilization in the connected state. As a result, water vapor enters the internal space.

  Further, water vapor may permeate into the endoscope in the outer skin of the curved portion or the soft portion made of a resin material.

  Furthermore, if pinholes or cracks occur in the endoscope exterior member, moisture may enter the endoscope when the endoscope is sterilized. In particular, in autoclave sterilization, an endoscope is placed in an environment of high-temperature and high-pressure steam, and thus the endoscope is not a little burdened by heat, pressure, and humidity. For this reason, when autoclave sterilization is repeatedly performed, deterioration or the like occurs in the exterior member of the endoscope. As a result, leakage may occur, and moisture may enter the endoscope.

  Moisture that has entered the endoscope once is difficult to dry as it is because of its structure. Especially in electronic endoscopes, the moisture that has entered the endoscope causes the image sensor and its peripheral circuits. There is a risk of causing an electrical failure in the electronic components constituting the. The endoscopic image obtained in such a state has a significant deterioration in image quality, and when the electronic component is destroyed, the image itself may not be displayed.

  As a countermeasure against this, a method of drying the inside of the endoscope after sterilizing the endoscope is effective. For this reason, it is important to grasp the humidity state inside the endoscope in order to confirm whether or not the inside of the endoscope (particularly, the distal end of the endoscope insertion portion) is sufficiently dried.

  On the other hand, an endoscope in which a humidity sensor is mounted at the tip of the endoscope insertion portion has been proposed (see, for example, Patent Documents 3 and 4). According to this endoscope, it is possible to grasp the humidity state at the tip of the endoscope insertion portion using the output of the humidity sensor.

JP 2002-58642 A JP 2000-107120 A JP-A-3-238625 JP-A-6-157

  However, in the endoscopes described in Patent Documents 3 and 4, a humidity sensor is provided at the distal end of the endoscope insertion portion independently of the CCD sensor, compared to an endoscope that does not include a humidity sensor. In addition, the diameter of the endoscope insertion portion is increased by the mounting space of the humidity sensor, which increases the patient's pain during insertion.

  Further, Patent Document 4 describes a configuration in which a CCD sensor and a humidity sensor are integrally provided on the same substrate. However, the CCD sensor and the humidity sensor must be formed by different processes. Therefore, it is difficult to achieve high integration and miniaturization, leading to an increase in diameter of the endoscope insertion portion.

  On the other hand, Patent Document 1 describes that a CMOS sensor and its peripheral circuit are formed on the same substrate by a CMOS process. This peripheral circuit is a circuit for extracting a signal output from the CMOS sensor, and is a signal processing circuit for performing signal processing of the signal output from the CMOS sensor, and a timing for extracting a signal from the CMOS sensor. A control system circuit for performing control is included.

  However, in Patent Document 1, it is not assumed at all that a humidity sensor having a completely different function from these circuits is provided on the same substrate as the CMOS sensor.

  The present invention has been made in view of such circumstances, and an electronic endoscope capable of grasping the humidity state of the distal end of the endoscope insertion portion without increasing the diameter of the distal end of the endoscope insertion portion. Another object of the present invention is to provide a manufacturing method thereof and an electronic endoscope system.

  In order to achieve the above object, an electronic endoscope of the present invention is provided at a distal end of an insertion portion to be inserted into a subject, and includes a CMOS type image sensor that images the inside of the subject, and the image sensor. A humidity sensor for detecting the humidity of the surrounding atmosphere, and the image sensor and the humidity sensor are integrally provided on the same semiconductor substrate. The image sensor and the humidity sensor are preferably formed on the semiconductor substrate by the same CMOS process.

  According to the present invention, by integrating the CMOS image sensor and the humidity sensor on the same semiconductor substrate, it becomes possible to share these ground lines, compared with the case where the humidity sensor is provided independently. Thus, downsizing and high integration can be achieved. Thereby, it becomes possible to grasp the humidity state of the distal end of the endoscope insertion portion from the output of the humidity sensor without increasing the diameter of the distal end of the endoscope insertion portion. As a result, the burden on the patient can be reduced, and failure of electronic components mounted on the distal end of the endoscope insertion portion can be prevented.

  The present invention shows a preferred embodiment, and by forming with the same CMOS process, it is possible to achieve downsizing and high integration, and it is possible to reduce the number of parts and the cost. .

  In the electronic endoscope of the present invention, it is preferable that the semiconductor substrate is provided with a circuit that changes an output frequency of the humidity sensor in accordance with humidity of an atmosphere surrounding the image sensor.

  By providing such a circuit, a stable output can be obtained from the humidity sensor, and the humidity state at the tip of the endoscope insertion portion can be grasped with high accuracy.

  In order to achieve the above object, a method of manufacturing an electronic endoscope according to the present invention includes a CMOS type image sensor that is provided at a distal end of an insertion portion that is inserted into a subject and images the inside of the subject. And a humidity sensor for detecting the humidity of the atmosphere surrounding the image sensor, wherein the image sensor and the humidity sensor are formed on the same semiconductor substrate by the same CMOS process. The process of forming integrally is included.

  According to the present invention, by integrating the CMOS image sensor and the humidity sensor on the same semiconductor substrate by the same CMOS process, these ground lines can be shared, and the humidity sensor can be made independent. Compared with the case where it provides, it can achieve size reduction and high integration. Thereby, it becomes possible to grasp the humidity state of the distal end of the endoscope insertion portion from the output of the humidity sensor without increasing the diameter of the distal end of the endoscope insertion portion. As a result, the burden on the patient can be reduced, and failure of electronic components mounted on the distal end of the endoscope insertion portion can be prevented.

  In the electronic endoscope manufacturing method according to the present invention, when the image sensor and the humidity sensor are integrally formed on the same semiconductor substrate, the humidity sensor according to the humidity of the atmosphere surrounding the image sensor. It is preferable to include a step of forming a circuit for changing the output frequency on the semiconductor substrate.

  By forming such a circuit on a semiconductor substrate, a stable output can be obtained from the humidity sensor, and the humidity state at the tip of the endoscope insertion portion can be grasped with high accuracy.

  In order to achieve the above object, the electronic endoscope system of the present invention is configured to determine whether the humidity detected by the electronic endoscope of the present invention and the humidity sensor is equal to or less than a specified value. Means.

  According to the present invention, various processes (for example, supply of power supply voltage and drying process) can be performed depending on whether or not the humidity of the atmosphere surrounding the image sensor is equal to or lower than a specified value. It is possible to prevent a failure of an electronic component mounted on the tip of the part.

  The electronic endoscope system according to the present invention further includes power control means for controlling a power supply voltage supplied to each of the image sensor and the humidity sensor, and the power control means is configured to determine the humidity by the determination means. It is preferable that the power supply voltage is supplied only to the humidity sensor until it is determined that the humidity is lower than the value, and the power supply voltage is supplied to the image sensor after the humidity is determined to be lower than the specified value.

  Since the power supply voltage is not supplied to the image sensor until the humidity of the atmosphere surrounding the image sensor becomes equal to or less than the specified value, it is possible to prevent a failure of an electronic component mounted on the distal end of the endoscope insertion portion.

  Moreover, it is preferable that the electronic endoscope system of the present invention further includes a drying unit that dries the inside of the electronic endoscope until the determination unit determines that the humidity is equal to or lower than the specified value.

  According to this aspect, since the inside of the endoscope is dried until it is determined that the humidity of the atmosphere surrounding the image sensor is equal to or less than the specified value, a failure of the electronic component mounted on the tip of the endoscope insertion portion can be prevented. Can be prevented.

  According to the present invention, it is possible to grasp the humidity state of the distal end of the endoscope insertion portion from the output of the humidity sensor without increasing the diameter of the distal end of the endoscope insertion portion. As a result, the burden on the patient can be reduced, and failure of electronic components mounted on the distal end of the endoscope insertion portion can be prevented.

Overall configuration diagram showing the schematic configuration of the electronic endoscope system Configuration diagram showing configuration example of CMOS sensor Block diagram showing the electrical configuration of the electronic endoscope system Schematic diagram showing the overall configuration of the CMOS sensor Configuration diagram showing a configuration example of a humidity sensor Process diagram showing manufacturing method of humidity sensor Circuit diagram showing an example of circuit configuration including humidity sensor Circuit diagram showing another example of circuit configuration including humidity sensor Circuit diagram showing still another example of the circuit configuration including the humidity sensor Flow chart showing the operation of the electronic endoscope system

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the electronic endoscope system 11 includes an electronic endoscope 12, a processor device 13, a light source device 14, and the like. The electronic endoscope 12 includes an insertion unit 16, a hand operation unit 17, a universal cord 18, and the like.

  Since the insertion portion 16 is inserted into the body of the subject, the insertion portion 16 is provided so as to be freely curved according to the shape of the body of the subject. The distal end portion 16a of the insertion portion 16 has a built-in imaging device equipped with a CMOS sensor. Furthermore, on the end face of the distal end portion 16a, an illumination window that irradiates illumination light forward, an observation window that guides light from the body of the subject to the CMOS sensor, a forceps outlet from which various treatment tools are led out, washing water, An air / water supply nozzle or the like through which air or the like is injected is provided.

  Further, a bending portion 19 is provided behind the tip portion 16a. The bending portion 19 is formed by connecting a plurality of bending pieces, and is connected to a bending operation knob 21 provided in the hand operation portion 17 by a wire inserted through the insertion portion 16. Therefore, the bending portion 19 is freely bent in a desired direction in the up, down, left, and right directions when the wire inserted into the insertion portion 16 is pushed and pulled by the turning operation of the bending operation knob 21 provided in the hand operation portion 17. To do.

  The hand operation unit 17 is provided with various operation buttons such as a forceps port 22 and an air / water supply button 23 in addition to the bending operation knob 21 for operating the bending portion 19 as described above. A treatment instrument such as an injection needle or a high-frequency knife is inserted into the forceps port 22. The air / water supply button 23 controls the air and water supplied from the air / water supply device.

  The universal cord 18 electrically connects the electronic endoscope 12 to the processor device 13 and optically connects the electronic endoscope 12 to the light source device 14 via a connector 24 provided at a base end portion thereof. To do.

  The processor device 13 is connected to the electronic endoscope 12, the light source device 14, the monitor 26, and the like, and comprehensively controls the operation of the electronic endoscope system 11. Further, the light source device 14 irradiates illumination light toward the observation site through the light guide (see FIG. 3) inserted through the universal cord 18 and the insertion portion 16.

  As described above, the electronic endoscope system 11 uses the CMOS sensor 31 as an image sensor. As shown in FIG. 2, the CMOS sensor 31 includes an imaging region 32, a vertical scanning circuit 33, a correlated double sampling (CDS) circuit 34, a column selection transistor 36, an output circuit 37, a horizontal scanning circuit 38, and the like.

  In the imaging region 32, pixels 41 are arranged in a matrix, and an image of an observation site is formed by an imaging optical system (not shown). The pixel 41 includes a photodiode D1, an amplification transistor M1, a pixel selection transistor M2, a reset transistor M3, and the like. The photodiode D1 generates and accumulates signal charges corresponding to the amount of incident light through photoelectric conversion. The signal charge accumulated in the photodiode D1 is amplified as an imaging signal by the amplifying transistor M1, and is output to the outside of the pixel 41 at a predetermined timing by the pixel selecting transistor M2. Further, the signal charge accumulated in the photodiode D1 is discarded by the reset transistor M3 at a predetermined timing.

  In the imaging region 32, a row selection line L1 and a row reset line L2 are wired in the horizontal direction (X direction) from the vertical scanning circuit 33, and column signal lines in the vertical direction (Y direction) from the CDS circuit 34. L3 is wired.

  The row selection line L1 is connected to the gate of the pixel selection transistor M2, and the row reset line L2 is connected to the gate of the reset transistor M3. The column signal line L3 is connected to the source of the pixel selection transistor M2 and is connected to the column selection transistor 36 of the corresponding column via the CDS circuit 34.

  The vertical scanning circuit 33 generates a vertical scanning signal at a predetermined timing based on a signal from the CPU 52, selects the row selection line L1 row by row, and outputs the imaging signal to the column signal line L3. Change a row (hereinafter referred to as a horizontal line). The vertical scanning circuit 33 selects the horizontal row reset line L2 one row at a time, and changes the horizontal line for discarding signal charges. Further, when the selected row of the row selection line L1 and the row reset line L2 reaches the horizontal line positioned at the end of the imaging region 32, the vertical scanning circuit 33 selects the top horizontal line again and performs the above-described operation. repeat.

  Based on the signal from the CPU 52, the CDS circuit 34 holds the imaging signal of the pixel 41 connected to the row selection line L1 selected by the vertical scanning circuit 33 at a predetermined timing, and performs noise removal.

  The horizontal scanning circuit 38 generates a horizontal scanning signal at a predetermined timing based on a signal from the CPU 52, and performs on / off control of the column selection transistor 36.

  The column selection transistor 36 is provided between the output bus line 43 connected to the output circuit 37 and the CDS circuit 34, and selects a pixel for transferring an imaging signal to the output bus line 43 in accordance with a horizontal scanning signal. To do. The output circuit 37 amplifies the image pickup signal sequentially transferred from the CDS circuit 34 to the output bus line 43, A / D converts it, and outputs it.

  As shown in FIG. 3, the electronic endoscope 12 is provided with the above-described CMOS sensor 31, the objective lens 51, the CPU 52, the light guide 53, and the like.

  The CMOS sensor 31 is provided at the distal end portion 16a of the insertion portion 16 as described above, and the objective lens 51 is disposed in front of the CMOS sensor 31. An observation window 54 is provided on the end face of the distal end portion 16 a of the insertion portion 16, and light from the subject incident from the observation window 54 is imaged on the imaging region 32 of the CMOS sensor 31 by the objective lens 51. The CMOS sensor 31 photoelectrically converts the subject image formed in the imaging region 32 for each pixel 41, accumulates signal charges corresponding to the exposure amount in each pixel 41, and outputs them as an imaging signal at a predetermined timing.

  The CPU 52 communicates with the CPU 61 of the processor device 13 and comprehensively controls each unit of the electronic endoscope 12. For example, the CPU 52 controls the operation so that the CMOS sensor 31 is driven at a predetermined timing based on a signal from the CPU 61 of the processor device 13.

  The light guide 53 is inserted into the universal cord 18 and the insertion portion 16, one end is connected to the illumination window 56 provided on the end surface of the distal end portion 16 a of the insertion portion 16, and the other end is connected to the light source device 14. Has been. The illumination light from the light source device 14 is irradiated from the illumination window 56 to the observation site through the light guide 53.

  As shown in FIG. 3, the processor device 13 includes a CPU 61, a DSP 62, a D / A conversion circuit 63, a memory 64, a power supply circuit 66, and the like.

  The CPU 61 controls the operation of each part of the processor device 13 and communicates with the CPU 52 of the electronic endoscope 12 and the CPU 71 of the light source device 14 to control the operation of the electronic endoscope 12 and the light source device 14. The electronic endoscope system 11 is comprehensively controlled.

  The memory 64 is a ROM that stores various programs for operating the CPU 61 and various setting information, a RAM that is a work area when executing a program read from the ROM, an EEPROM that stores various other data, and the like. Consists of

  The DSP 62 performs various signal processes such as S / P conversion, color interpolation, white balance adjustment, and gamma correction on the imaging signal output from the CMOS sensor 31. The imaging signal output from the CMOS sensor 31 is held in the memory 64 as image data when various image processing is performed by the DSP 62. The DSP 62 reads out necessary image data from the memory 64, converts it into a video signal such as an NTSC signal, and D / A converts it by the D / A conversion circuit 63, thereby displaying the image data on the monitor 26. .

  The power supply circuit 66 supplies various power supply voltages to each part of the processor device 13 and each part of the electronic endoscope 12. The power supply circuit 66 receives the instruction from the CPU 61 and starts supplying the power supply voltage.

  As shown in FIG. 3, the light source device 14 includes a CPU 71, a light source 72, a wavelength selection filter 73, and the like. The CPU 71 communicates with the CPU 61 of the processor device 13 and controls the light source device 14 by driving the light source 72 and the wavelength selection filter 73 in accordance with the drive timing of the CMOS sensor 31 and the like.

  The light source 72 is a high-intensity light source that emits high-intensity light over a wide wavelength band, such as a xenon lamp or a halogen lamp, and the CPU 71 controls switching on and off. Further, the light emitted from the light source 72 is efficiently guided to the light guide 53 by the condenser lens 74.

  The wavelength selection filter 73 is a filter that restricts the light emitted from the light source 72 to light in a specific wavelength band, and is inserted or retracted between the light source 72 and the condenser lens 74 based on an instruction from the CPU 71. Is done. As a result, the light source device 14 can freely switch the wavelength band of the illumination light as necessary, such as settings and doctor operations. For example, the light source device 14 can output not only white visible light but also light other than visible light such as infrared light and special light in which the ratio of RGB components of visible light is adjusted. It has become.

  Next, a characteristic configuration of the electronic endoscope system 11 according to the present embodiment will be described.

  FIG. 4 is a schematic diagram showing the overall configuration of the CMOS sensor 31. As shown in FIG. 4, the CMOS sensor 31 includes an imaging region 32 and a peripheral circuit region 102 on a semiconductor substrate 100, and a humidity in which a humidity sensor 104 that detects the humidity of the atmosphere surrounding the CMOS sensor 31 is disposed. A sensor area 106 is provided. In the peripheral circuit region 102, the vertical scanning circuit 33, the horizontal scanning circuit 38, the CDS circuit 34, the output circuit 37, and the like shown in FIG.

  FIG. 5 is a configuration diagram illustrating a configuration example of the humidity sensor 104. FIG. 5A is a plan view of the humidity sensor 104, and FIG. 5B is a cross-sectional view of the humidity sensor 104 (a cross-sectional view taken along line AA in FIG. 5A).

  The humidity sensor 104 shown in FIG. 5 is a resistance type humidity sensor that outputs a change in resistance value corresponding to a change in humidity as an electrical signal (humidity signal). The humidity sensor 104 is provided on the same semiconductor substrate 100 as the CMOS sensor 31 with an insulating film 112 interposed therebetween, and is provided with a pair of electrodes 108A and 108B disposed so as to be opposed to each other on the same plane, and the electrode 108A. , 108B and a moisture sensitive film 110 formed so as to cover the electrodes, and output terminal portions 109A and 109B formed at the ends of the electrodes 108A and 108B, respectively.

  The shape of the electrodes 108A and 108B is not particularly limited. However, in this embodiment, as shown in FIG. 5, the electrodes 108A and 108B have a comb-like shape, and the comb-tooth portions mesh with each other and face each other. Is used. Thereby, since the several comb-tooth part each provided in electrode 108A, 108B mutually meshes | engages and opposes, an opposing area can be enlarged, making arrangement | positioning area as a whole electrode small. Therefore, the humidity detection accuracy of the atmosphere surrounding the humidity sensor 104 can be improved.

  The moisture sensitive film 110 changes the resistance value between the electrodes 108A and 108B in accordance with the amount of moisture absorbed or released, and as shown in FIG. 5, covers the electrodes 108A and 108B and the gap between these electrodes. It is comprised by the formed high molecular polymer (for example, polyimide polymer etc.).

  Here, the manufacturing method of the humidity sensor 104 of this embodiment is demonstrated, referring FIG. FIG. 6 is a process diagram showing a method for manufacturing the humidity sensor 104.

  First, the circuit pattern of the imaging region 32 and the peripheral circuit region 102 of the CMOS sensor 31 is formed on the semiconductor substrate 100 by a known CMOS process, and the humidity sensor region 106 of the semiconductor substrate 100 is formed by the same CMOS process. 104 is formed.

  Specifically, as shown in FIG. 6A, after a silicon nitride film (SiN film) or the like is formed as an insulating film 112 on the semiconductor substrate 100, electrode patterns of electrodes 108A and 108B are formed on the insulating film 112. Form. A method for forming the electrode pattern is not particularly limited. For example, after an electrode film is formed on the entire surface of the insulating film 112, the electrode film is patterned into a predetermined shape using a known photolithography technique.

  At this time, in order to obtain a stable output from the humidity sensor 104, a circuit pattern having the circuit configuration shown in FIG. 7 is formed at the same time. The circuit configuration shown in FIG. 7 includes an astable multivibrator transmission circuit including a resistor, a capacitor, an operational amplifier, and the like. By connecting the humidity sensor 104 and the capacitor in series, an output having a frequency corresponding to humidity is obtained. Be able to. Further, the circuit configuration is not limited to the circuit configuration illustrated in FIG. 7, and for example, the circuit configuration illustrated in FIG. 8 or FIG. 9 is possible. The circuit configurations shown in FIGS. 7 to 9 are well known as described in, for example, Japanese Patent Laid-Open No. 61-104246, and thus detailed description thereof is omitted here.

  Next, as shown in FIG. 6B, a protective film 116 is formed so as to cover the entire circuit (including the electrode patterns of the electrodes 108A and 108B) arranged in the humidity sensor region 106.

  Next, as shown in FIG. 6C, the sensor portion 104 a of the humidity sensor 104 is exposed by polishing and removing a part of the protective film 116. The sensor unit 104a of the humidity sensor 104 is an electrode facing region where the comb teeth of the electrodes 108A and 108B face each other.

  Next, as shown in FIG. 6D, a polymer polymer is formed as the moisture sensitive film 110 on the sensor unit 104 a of the humidity sensor 104. The method for forming the moisture-sensitive film 110 is not particularly limited, and for example, the moisture-sensitive film 110 can be formed by applying a high molecular weight polymer by spin coating or printing and then heat-curing. Thereby, the humidity sensor 104 of this embodiment is completed.

  In the humidity sensor 104 configured as described above, the amount of moisture absorbed or released by the moisture sensitive film 110 changes, and the resistance value between the electrodes 108A and 108B changes. The frequency of the electrical signal (humidity signal) output from the humidity sensor 104 changes due to the change in resistance value. That is, the humidity sensor 104 outputs an electrical signal having a frequency corresponding to the humidity of the atmosphere surrounding the CMOS sensor 31 as a humidity signal.

  As illustrated in FIG. 3, the processor device 13 includes a humidity calculation unit 120 that calculates the humidity of the distal end portion 16 a of the insertion unit 16 based on the humidity signal output from the humidity sensor 104. Further, the memory 64 stores a humidity table in which the relationship between the output frequency of the humidity sensor 104 and the humidity is converted into a data table. This humidity table is obtained in advance by experiments or the like. The humidity calculation unit 120 refers to the humidity table stored in the memory 64, so that the humidity of the distal end portion 16 a of the insertion unit 16 from the frequency of the humidity signal output from the humidity sensor 104, that is, the atmosphere surrounding the CMOS sensor 31. Find the humidity.

  The processor device 13 is also provided with a drying unit 124 for drying the inside of the electronic endoscope 12 and a display lamp 126 that indicates whether or not the drying by the drying unit 124 has been sufficiently performed.

  The drying unit 124 is provided with an air supply pump (not shown) for supplying gas into the electronic endoscope 12 and a suction pump (not shown) for sucking the gas inside the electronic endoscope 12. Yes. The drying unit 124 supplies and sucks gas through an air supply port and a suction port (not shown) provided in the connector 24 of the electronic endoscope 12 in accordance with an instruction from the CPU 61, and thereby the electronic endoscope 12. Dry inside.

  The display lamp 126 is a display unit that indicates whether or not the inside of the electronic endoscope 12 has been sufficiently dried in accordance with an instruction from the CPU 61. The display mode of the display lamp 126 is not particularly limited as long as the operator can visually grasp it. For example, when the inside of the electronic endoscope 12 is NG, the display lamp is lit red. In the case of OK, there are a mode in which it is lit in green, a mode in which it is flashed in the case of NG, and a mode in which it is lit in the case of OK. Whether or not the inside of the electronic endoscope 12 has been sufficiently dried is determined by the CPU 61 based on the humidity of the atmosphere surrounding the CMOS sensor 31, as will be described later.

  Next, the operation of the electronic endoscope system 11 of the present embodiment will be described with reference to FIG. The operation shown in FIG. 10 is performed when the electronic endoscope 12 is connected to the processor device 13, and is executed by the CPU 61 in accordance with a program stored in the memory 64.

  First, when the electronic endoscope 12 is connected to the processor device 13, the CPU 61 instructs the drying unit 124 to start a drying process (step S10). The drying unit 124 turns on the air supply pump and the suction pump to supply gas into the electronic endoscope 12 and start intake.

  Next, the CPU 61 operates a timer (not shown) mounted on the processor device 13 and waits until a predetermined time elapses (step S12).

  After the predetermined time has elapsed, the CPU 61 instructs the power supply circuit 66 to energize the humidity sensor 104 (step S14). The power supply circuit 66 supplies a predetermined power supply voltage to the humidity sensor 104. When the power supply voltage is supplied to the humidity sensor 104, an electrical signal having a frequency corresponding to the humidity is output from the humidity sensor 104 as a humidity signal, and the humidity signal is input to the humidity calculation unit 120 of the processor device 13. The humidity calculation unit 120 refers to the humidity table stored in the memory 64, calculates the humidity of the atmosphere surrounding the CMOS sensor 31, and notifies the CPU 61 of the calculation result.

  Next, the CPU 61 determines whether or not the humidity calculated by the humidity calculation unit 120 is not more than a specified value (for example, 50% or less) (step S18). If the humidity is not lower than the specified value, it is determined that the inside of the electronic endoscope 12 is not sufficiently dried, and therefore the CPU 61 performs NG display (for example, lighting in red) on the display lamp 126 (step S26). ), Returning to step S12, the same processing is repeated until the humidity falls below a specified value.

  On the other hand, when it is determined in step S18 that the humidity is equal to or lower than the specified value, the CPU 61 performs OK display (for example, lighting in green) on the display lamp 126 (step S20).

  Next, the CPU 61 instructs the drying unit 124 to end the drying process (step S22). The drying unit 124 turns off the air supply pump and the suction pump, and stops the gas supply and intake to the inside of the electronic endoscope 12.

  Next, the CPU 61 instructs the power supply circuit 66 to energize each part of the electronic endoscope 12 (step S24). The power supply circuit 66 supplies a predetermined power supply voltage to each part of the electronic endoscope 12. Thereafter, after the operation of each part of the electronic endoscope 12 is confirmed, diagnosis using the electronic endoscope 12 is possible.

  As described above, according to the present embodiment, by integrating the CMOS sensor 31 and the humidity sensor 104 on the same semiconductor substrate 100, they can be formed by the same CMOS process. Compared with the case where 104 is provided independently, a common ground line can be used, and miniaturization and high integration can be achieved. As a result, the burden on the patient can be reduced without increasing the diameter of the distal end portion 16a of the insertion portion 16.

  Further, in the present embodiment, when the resistance value between the electrodes 108A and 108B of the humidity sensor 104 changes in accordance with a change in the surrounding humidity surrounding the CMOS sensor 31, the output frequency of the humidity sensor 104 changes, and the humidity sensor 104 changes according to the humidity. A humidity signal with a frequency is output from the humidity sensor 104. For this reason, a stable rectangular wave output can be obtained in a wide range of resistance values of the humidity sensor 104 and can be realized with a simple circuit configuration, so that the humidity sensor can be reduced while reducing the diameter of the insertion portion 16. It is possible to stably detect the humidity without being affected by the characteristic variation or characteristic deterioration of 104. Thereby, it is possible to grasp the humidity state of the distal end portion 16a of the insertion portion 16 with high accuracy even with a slight change in humidity. As a result, it becomes possible to easily detect whether or not the inside of the electronic endoscope 12 has been sufficiently dried, and to prevent a failure of the electronic component mounted on the distal end portion 16a of the insertion portion 16 in advance. Is possible.

  In this embodiment, a resistance type humidity sensor is used as the humidity sensor 104. However, the present invention is not limited to this, and a capacitance type humidity sensor that detects a change in capacitance value corresponding to a change in humidity. It is also possible to use. Note that a known humidity sensor may be used, and thus the description thereof is omitted here.

  Further, in the present embodiment, the aspect in which the drying unit 124 is provided in the processor device 13 has been described. You may dry the inside of. In this case, ON / OFF of the drying device is automatically controlled according to an instruction from the CPU 61 of the processor device 13.

  In the present embodiment, the display lamp 126 is provided in the processor device 13. However, the present invention is not limited to this. For example, the monitor 26 connected to the processor device 13 is used to connect the interior of the electronic endoscope 12. It may be displayed whether or not the drying is sufficiently performed. Further, an audio sound such as a speaker may be used to emit a warning sound or the like when, for example, the inside of the electronic endoscope 12 is not sufficiently dried. The operator can easily grasp visually or acoustically the dry state inside the electronic endoscope 12, that is, the humidity state of the distal end portion 16 a of the insertion portion 16, and the electronic endoscope 12 that has been sterilized and sterilized. Therefore, it is possible to prevent the electronic component mounted on the distal end portion 16a of the insertion portion 16 from being broken in advance.

  As described above, the electronic endoscope, the manufacturing method thereof, and the electronic endoscope system of the present invention have been described in detail. However, the present invention is not limited to the above examples, and various types can be made without departing from the gist of the present invention. Of course, improvements and modifications may be made.

  DESCRIPTION OF SYMBOLS 11 ... Electronic endoscope system, 12 ... Electronic endoscope, 13 ... Processor apparatus, 14 ... Light source device, 16 ... Insertion part, 16a ... Tip part, 17 ... Hand operation part, 26 ... Monitor, 31 ... CMOS sensor, 32 ... Imaging region, 33 ... Vertical scanning circuit, 34 ... CDS circuit, 37 ... Output circuit, 38 ... Horizontal scanning circuit, 41 ... Pixel, 52 ... CPU, 61 ... CPU, 64 ... Memory, 66 ... Power supply circuit, 100 ... Semiconductor substrate 102 ... Peripheral circuit area 104 ... Humidity sensor 106 ... Humidity sensor area 108A, 108B ... Electrode 110 ... Humidity sensitive film 116 ... Protective film 120 ... Humidity calculation unit 124 ... Drying unit 126 ... Indicator lamp

Claims (8)

A CMOS image sensor that is provided at the distal end of an insertion portion to be inserted into the subject and images the inside of the subject;
A humidity sensor for detecting the humidity of the atmosphere surrounding the image sensor,
The electronic endoscope, wherein the image sensor and the humidity sensor are integrally provided on the same semiconductor substrate.   The electronic endoscope according to claim 2, wherein the image sensor and the humidity sensor are formed on the semiconductor substrate by the same CMOS process.   The electronic endoscope according to claim 1, wherein the semiconductor substrate is provided with a circuit that changes an output frequency of the humidity sensor in accordance with a humidity of an atmosphere surrounding the image sensor. A CMOS image sensor that is provided at the distal end of an insertion portion to be inserted into the subject and images the inside of the subject;
A humidity sensor for detecting the humidity of the atmosphere surrounding the image sensor, and a manufacturing method of an electronic endoscope comprising:
An electronic endoscope manufacturing method including a step of integrally forming the image sensor and the humidity sensor on the same semiconductor substrate by the same CMOS process.   When the image sensor and the humidity sensor are integrally formed on the same semiconductor substrate, a circuit for changing the output frequency of the humidity sensor according to the humidity of the atmosphere surrounding the image sensor is formed on the semiconductor substrate. The manufacturing method of the electronic endoscope of Claim 4 including a process. The electronic endoscope according to any one of claims 1 to 3,
Determination means for determining whether or not the humidity detected by the humidity sensor is below a specified value;
An electronic endoscope system comprising: Power supply control means for controlling power supply voltages respectively supplied to the image sensor and the humidity sensor;
The power supply control means supplies a power supply voltage only to the humidity sensor until the determination means determines that the humidity is equal to or less than the specified value, and after the humidity is determined to be equal to or less than the specified value, The electronic endoscope system according to claim 6, wherein a power supply voltage is supplied to the image sensor.   8. The electronic endoscope system according to claim 6, further comprising a drying unit configured to dry the inside of the electronic endoscope until the determination unit determines that the humidity is equal to or less than the specified value.

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