WO2011102200A1

WO2011102200A1 - Electronic endoscope system

Info

Publication number: WO2011102200A1
Application number: PCT/JP2011/051598
Authority: WO
Inventors: 毅芦田; 安土遠藤; 加賀谷　淳; 正行高平; 貴行仲村
Original assignee: 富士フイルム株式会社
Priority date: 2010-02-19
Filing date: 2011-01-27
Publication date: 2011-08-25
Also published as: CN102781306B; CN102781306A; JP5537645B2; JPWO2011102200A1

Abstract

If it is determined that an insertion section has not been inserted into a body cavity, then the mode is switched from a normal mode to a second restricted mode, and the upper limit (Lx) of the light amount for the light illuminated on an observation region is reduced from L0 [1m] to L2 [1m]. Once it has been determined that the insertion section (16) has not been inserted into a body cavity, whether or not the insertion section (16) has been inserted into a body cavity is again successively determined. If it is determined that the insertion section has been inserted, then the second restriction mode is cancelled and the mode returned to normal mode, and the upper limit (Lx) is increased from L2 [1m] to L0 [1m]. Once it has been determined that the insertion section (16) has been inserted into a body cavity, whether or not a temperature difference (ΔT) [˚C ] exceeds a threshold value (T1) [˚C ] is successively determined. If the temperature difference (ΔT) [˚C ] exceeds the threshold value (T1) [˚C ], the mode is switched from normal mode to a first restriction mode, and the upper limit (Lx) is reduced from L0 [1m] to L1 [1m].

Description

Electronic endoscope system

The present invention relates to an electronic endoscope system that has an endoscope inserted into a body cavity and is used for diagnosis.

Conventionally, in the medical field, many endoscopic examinations using an electronic endoscope have been performed. The electronic endoscope includes an elongated insertion portion that is inserted into a body cavity. An imaging device such as a CCD or a CMOS is built in the distal end of the insertion portion. In addition, an exit window that emits light toward the observation site of the body cavity is provided at the distal end of the insertion portion. A light guide (optical fiber) is disposed in the insertion portion, and light from the light source device connected to the electronic endoscope is guided to the exit window through the light guide. The imaging device images light from the observation site, and the captured image is displayed on the monitor after various processing is performed by the processor device. The image displayed on the monitor is observed by a doctor.

The light source device is provided with a halogen lamp or a xenon lamp as a light source. A diaphragm for adjusting the amount of light incident on the light guide is provided between the base end of the light guide and the light source. The amount of light exiting from the exit window (hereinafter referred to as exit light) is adjusted by the diaphragm. The aperture of the diaphragm is controlled based on the brightness of the image obtained by the imaging device. When the amount of incident light incident on the imaging device is large, the aperture amount is reduced to reduce the amount of outgoing light, and when the amount of incident light is small, the aperture amount is increased to increase the amount of outgoing light. By performing such light amount control, the brightness of the image is properly maintained.

If the aperture of the diaphragm is large and the amount of emitted light is large, the temperature at the tip of the insertion portion rises due to heat generated by the emitted light. For example, during preparation for endoscopy, the endoscope is placed on a hanger or the like of a cart while the light source device is turned on and the light source is turned on. When the endoscope insertion portion is not inserted into the body cavity, the amount of incident light is reduced because the observation site does not exist near the insertion portion when compared with the state where the endoscope insertion portion is inserted into the body cavity. small. Therefore, the aperture of the diaphragm is large, the state of excess light quantity of the emitted light continues, and the tip temperature rises.

When the temperature rises, the image pickup apparatus breaks down, noise is added to the signal from the image pickup apparatus, and the like affects the image quality. Therefore, a countermeasure for suppressing the temperature rise at the tip of the insertion portion has been proposed ( For example, see Patent Document 1).

In the electronic endoscope described in Patent Document 1, when the state in which the amount of emitted light exceeds the threshold value continues for a predetermined time, the upper limit value of the range of light amount control by the diaphragm is set to the normal upper limit value set at the time of activation. Change to something smaller. When the upper limit value of the light amount control range is reduced, the maximum light amount of the emitted light is reduced, so that the amount of heat generated at the tip of the insertion portion is also reduced, and the temperature rise is suppressed.

JP 2002-282207 A

However, the light quantity control for temperature suppression described in Patent Document 1 has the following problems because only one upper limit value can be set. That is, if the upper limit value of the light amount control range is set high, useless heat generation cannot be suppressed during standby when the endoscope is not inserted into the body cavity, and the temperature rise at the distal end of the insertion portion cannot be sufficiently suppressed. . During standby, the amount of emitted light is sufficient to be able to confirm that the light source is turned on. In recent years, there is a concern about an increase in the amount of heat generated by the imaging apparatus itself due to an increase in the number of pixels and a decrease in heat dissipation due to a reduction in the diameter of the insertion portion.

From the viewpoint of suppressing unnecessary heat generation during standby, it is better to set the upper limit value of the light amount limit range in the light amount limit mode as low as possible. However, when the light amount control for suppressing the temperature is started during observation, the image becomes extremely dark as compared with the normal case, which causes a problem of giving the operator anxiety.

The present invention has been made in view of the above problems, and sufficiently suppresses the temperature rise at the distal end of the insertion portion during standby, and even when temperature suppression is started during observation, the operator feels uneasy. It is an object of the present invention to provide an electronic endoscope system that does not give the above.

In order to achieve the above object, an electronic endoscope system according to the present invention includes an emitting unit that emits outgoing light to the outside, an incident unit that receives light from the outside, and imaging that captures incident light that has entered the incident unit. An endoscope having an insertion portion provided at the tip thereof, a light amount control means for measuring the light amount of the incident light, and controlling the light amount of the emitted light within a predetermined upper limit value, and Whether the temperature determination means for determining whether or not the temperature of the tip exceeds a preset temperature threshold value, and whether the insertion portion is inserted into a body cavity or in a standby state outside the body cavity When determining that the insertion portion is in the inserted state by the insertion determining means and the insertion determining means, and the temperature determining means determines that the temperature of the tip has exceeded the temperature threshold, The upper limit is set at startup. When the insertion determination unit determines that the insertion unit is in the standby state, the upper limit value is set to a value L2 smaller than the value L1. And a temperature suppression means for suppressing a temperature rise at the tip by setting the upper limit value.

It is preferable that the insertion determination unit determines that the insertion unit is in the standby state when the amount of the emitted light continues for a predetermined time at the upper limit value L0.

Preferably, the insertion determination unit determines that the insertion unit is in the insertion state when the light amount of the incident light measured by the light amount control unit exceeds a preset light amount threshold value.

When the upper limit value is set to the value L2, when the insertion determination unit determines that the insertion portion is in the insertion state, the temperature suppression unit changes the upper limit value from the value L2 to the value L0. It is preferable to automatically return to

After the upper limit value is set to the value L1, the temperature suppression unit prohibits a release operation for returning the upper limit value from the value L1 to the value L0 unless the temperature at the tip is equal to or lower than the temperature threshold value. It is preferable to do.

The temperature determination unit performs a calculation using a light amount control history indicating a transition of a light amount change of the emitted light controlled by the light amount control unit, and the temperature of the tip exceeds the temperature threshold based on the calculation result. It is preferable to determine whether or not.

It is preferable that the temperature determination unit obtains an estimated value of the current temperature of the tip using the light amount control history and compares the estimated value with the temperature threshold value.

The temperature determination means calculates the estimated value at regular time intervals, adds the temperature increase from the previous time to the current time based on the light amount control history to the calculated previous estimated value, It is preferable to obtain the estimated value at this time by subtracting the temperature decrease due to the heat dissipation until.

It is preferable that the temperature determination unit obtains an integrated value of the light amount of the emitted light based on the light amount control history, and determines based on the integrated value.

It is preferable that the temperature determination means obtains the integrated value by decreasing the weight of the older light quantity control history.

It is preferable that the temperature determination means collates an actual measurement value measured by a temperature sensor provided at the tip with the temperature threshold value.

A light source that illuminates with a substantially constant light amount, and a diaphragm adjustment mechanism that adjusts a light amount of the emitted light by adjusting an opening amount of a diaphragm opening disposed on an optical path of light emitted from the light source, and the temperature Preferably, the suppressing means limits the upper limit of the opening amount of the aperture adjustment mechanism by the value L1 and the value L2.

It is preferable that a light source capable of controlling the light emission amount is provided, and the temperature suppressing unit limits the upper limit of the light emission amount of the light source by the value L1 and the value L2.

According to the present invention, when it is determined that the insertion portion is inserted into the body cavity and it is determined that the temperature of the distal end of the insertion portion exceeds a preset temperature threshold, the amount of emitted light is controlled. The upper limit value is set to the first limit value L1 that is lower than the upper limit value L0 that is set at the time of activation, and the upper limit value is the first limit value when it is determined that the insertion portion is outside the body cavity. Since the second limit value L2 lower than L1 is set, the electronic endoscope in a state where the power is turned on and irradiated with the emitted light is hung on a hanger or the like, and preparations for inserting the insertion portion into the body cavity are made. The temperature at the distal end of the insertion portion is prevented from rising while the insertion portion is inserted and while the insertion portion is inserted into the body cavity and the diagnosis is performed.

It is an external view of an electronic endoscope system. It is a block diagram which shows the electric constitution of an electronic endoscope system. It is a block diagram explaining the detail of the aperture adjustment mechanism in CPU in a processor apparatus and a light source device. It is a table which shows the upper limit Px of the PWM value in each mode, the opening of the aperture opening, and the upper limit Lx of the quantity of emitted light. It is a graph which shows a time history, (A) is related with the temperature rise value (DELTA) T in the front-end | tip of an insertion part, (B) is related with the upper limit Lx of light quantity. It is a flowchart explaining the temperature control in the front-end | tip of an insertion part. It is a graph which shows the relationship between temperature rise value (DELTA) T in the front-end | tip of an insertion part, and the upper limit Px of PWM value. It is a graph which shows the time history of the upper limit Lx of light quantity. It is a block diagram explaining the calculation which calculates | requires the temperature difference in the front-end | tip of the insertion part of 3rd Embodiment. It is a flowchart explaining the temperature control in the front-end | tip of the insertion part of 3rd Embodiment. It is a graph which shows the time history regarding the light quantity _LN of 4th Embodiment. It is a flowchart explaining the temperature control in the front-end | tip of the insertion part of 4th Embodiment. It is a graph which shows the time history regarding the light quantity _LN of 5th Embodiment. It is a block diagram which shows the electric constitution of the electronic endoscope system of 6th Embodiment.

[First Embodiment]
The electronic endoscope system 11 of the first embodiment shown in FIG. 1 is used for patient examination. The electronic endoscope system 11 illuminates an observation region, an electronic endoscope 12 for imaging an observation region of a body cavity, a processor device 13 that generates an image of the observation region based on a signal obtained by the imaging, and the observation region. A light source device 14 for supplying the emitted light and a monitor 15 for displaying an image of the observation site.

The electronic endoscope 12 includes a flexible insertion portion 16 to be inserted into a body cavity, an operation portion 17 connected to a proximal end portion of the insertion portion 16, the operation portion 17, a processor device 13, and a light source device 14. And a connector 19 attached to a proximal end portion of the universal cord 18.

The insertion portion 16 has, for example, an elongated shape with an outer diameter of 6 mm and is covered with a flexible tube. The operation unit 17 includes operation members such as a release button 20 for recording a still image and an air / water supply button (not shown).

The connector 19 is a composite type composed of a communication connector and a light source connector. The connector 19 removably connects the electronic endoscope 12 to the processor device 13 and the light source device 14.

At the distal end 16a of the insertion portion 16, an emission window 27 (see FIG. 2) that emits the light supplied from the light source device 14 to the outside, an incident window 28 (see FIG. 2) for taking in external light, and an incident light CCD 30 (refer FIG. 2) which images the external light (henceforth incident light) which injected into the window 28 is provided. By directing the distal end 16a of the insertion portion 16 inserted into the body cavity toward the observation site, the light supplied from the light source device 14 is reflected by the observation site. The light reflected by the observation site enters the incident window 28. An image of the observation site can be obtained by imaging incident light.

The processor device 13 is electrically connected to the electronic endoscope 12, the light source device 14, and the monitor 15, and comprehensively controls the operation of the entire electronic endoscope system 11. The processor device 13 includes a monitor lamp 21 that displays the operation state of the electronic endoscope system 11 on the front surface thereof.

As shown in FIG. 2, the electronic endoscope 12 includes a light guide 26, an exit window 27, an entrance window 28, a condenser lens 29, a CCD 30, and an analog front end (hereinafter abbreviated as AFE) 31. And a CCD drive circuit 32 and a temperature sensor 33.

The light guide 26 guides the light supplied from the light source device 14 to the distal end 16a of the insertion portion 16. The emission window 27 emits the light guided by the light guide 26 to the outside. The incident window 28 guides incident light to the condenser lens 29. The condensing lens 29 condenses incident light on the CCD 30. The CCD 30 performs an imaging operation according to the drive pulse from the CCD drive circuit 32, and inputs an imaging signal corresponding to the amount of light from the condenser lens 29 to the AFE 31. A CMOS image sensor may be used instead of the CCD.

The AFE 31 is a correlated double sampling circuit (hereinafter abbreviated as CDS), an automatic gain control circuit (hereinafter abbreviated as AGC), and an analog / digital converter (hereinafter abbreviated as A / D) (all shown). (Omitted). Each part of the AFE 31 operates based on a synchronization pulse from the CCD drive circuit 32. The CDS performs correlated double sampling processing on the imaging signal input from the CCD 30, and removes reset noise and amplifier noise generated by the CCD 30. The AGC converts the imaging signal amplified by the CDS into a digital imaging signal having a predetermined number of bits and inputs the digital imaging signal to the processor device 13. In the processor device 13, an image is generated based on the imaging signal.

The CCD drive circuit 32 generates a drive pulse (vertical / horizontal scanning pulse, electronic shutter pulse, readout pulse, reset pulse, etc.) of the CCD 30 and a synchronization pulse for the AFE 31 based on a signal from the processor device 13.

The temperature sensor 33 is provided at the tip 16a of the insertion portion 16, and detects the temperature T [° C.] at the tip 16a. The temperature sensor 33 inputs the detected temperature T [° C.] to the processor device 13.

The processor device 13 includes a CPU 36, a ROM 37, a RAM 38, a digital signal processing unit (hereinafter abbreviated as DSP) 39, a digital image processing circuit (hereinafter abbreviated as DIP) 40, and a display control circuit 41. I have.

The CPU 36 controls the overall operation of the processor device 13. The CPU 36 is connected to each unit via a data bus, an address bus, and a control line (all not shown). The CPU 36 operates each unit in response to an operation signal from the operation unit 42. The operation unit 42 is a known input device such as an operation panel provided on the housing of the processor device 13, buttons on the operation unit 17 (see FIG. 1) of the electronic endoscope 12, or a mouse or a keyboard.

The ROM 37 stores various programs (OS, application programs, etc.) and data (graphic data, etc.) for controlling the operation of the processor device 13. The RAM 38 is a working memory from which necessary programs and data are read from the ROM 37. The program read to the RAM 38 is sequentially processed by the CPU 36.

The DSP 39 includes a frame memory (not shown). The frame memory temporarily stores the imaging signal from the AFE 31. The DSP 39 reads an image pickup signal from the frame memory, performs various signal processing such as color separation, color interpolation, gain correction, white balance adjustment, and gamma correction, and generates an image for one frame. The DSP 39 inputs the generated image to the DIP 40.

The DIP 40 includes a frame memory (not shown). The frame memory temporarily stores an image from the DSP 39. The DIP 40 reads an image from the frame memory and performs various image processing such as electronic scaling, color enhancement, and edge enhancement. The DIP 40 inputs an image subjected to various image processes to the display control circuit 41.

The display control circuit 41 includes a VRAM (not shown). The VRAM temporarily stores the image from the DIP 40. The display control circuit 41 receives graphic data stored in the ROM 37. Graphic data includes a display mask that hides the ineffective pixel region of the in-vivo image and displays only the effective pixel region, character information such as examination date and time, or patient and surgeon information, and a graphical user interface (GUI). Etc.

The display control circuit 41 reads an image from the VRAM and performs various display control processes such as a display mask, character information, GUI superimposition processing, and drawing processing on the display screen of the monitor 15. The display control circuit 41 converts the image subjected to various display control processes into a video signal (component signal, composite signal, etc.) corresponding to the display format of the monitor 15 and displays it on the monitor 15.

In addition to the above, the processor device 13 performs a compression processing circuit for compressing an image in a predetermined format (for example, JPEG format), and the compressed image is linked to the operation of the release button 20 by using a CF card, optical Media I / F for recording on removable media such as magnetic disks (MO) and CD-Rs, and network I / F (all not shown) for controlling transmission of various data to and from networks such as LAN Yes. These are connected to the CPU 36 via a data bus (not shown) or the like.

The light source device 14 includes a CPU 46, a light source 47, a light source driver 48, an aperture adjustment mechanism 49, a motor 50, a motor driver 51 that drives the motor 50, and a condenser lens 52.

The CPU 46 communicates with the CPU 36 of the processor device 13 and controls the overall operation of the light source device 14. The CPU 46 is connected to each unit via a data bus, an address bus, and a control line (all not shown).

The light source 47 is a halogen lamp or a xenon lamp that generates white light. The light source 47 is driven by a light source driver 48 and is lit with a substantially constant light amount, and the light from the light source 47 is incident on the condenser lens 52. The aperture adjustment mechanism 49 is disposed on the optical path of the light source 47 and adjusts the aperture amount of the aperture opening 57 (see FIG. 3). Light having a light amount corresponding to the opening amount of the aperture opening 57 enters the condenser lens 52. The motor 50 is rotated by the drive pulse input from the motor driver 51 and drives the aperture adjustment mechanism 49. The condenser lens 52 condenses the light that has passed through the aperture adjusting mechanism 49 and guides it to the incident end of the light guide 26.

As shown in FIG. 3, the CPU 36 of the processor device 13 functions as a light amount control unit 53, an insertion determination unit 54, a temperature determination unit 55, and a temperature suppression unit 56.

Light quantity control unit 53, by calculating the average luminance value of all pixels in the effective pixel area based on one frame imaging signal from CCD 30 (photometric value L _M), for measuring the amount of the incident light L _in . The light amount control unit 53 outputs a light amount control signal for requesting the light amount of the emitted light L _{out to} the light source device 14 so that the photometric value L _M becomes the reference value L _S for keeping the brightness of the image constant. The amount of outgoing light L _out is controlled through the light source device 14. Specifically, the light quantity control unit 53, when the photometric value L _M is smaller than the reference value L _S, as the photometric value L _M is the reference value L _S, the light amount of the shortage of the outgoing light L _out, That is, a light amount control signal requesting the necessary light amount is sent. Also, if the photometric value L _M exceeds the reference value L _S, as the photometric value L _M is the reference value L _S, and sends a light amount control signal requesting a decrease in excess of the amount of light of the outgoing light L _out .

The CPU 46 of the light source device 14 controls the aperture adjustment mechanism 49 based on the light amount control signal input from the light amount control unit 53. The CPU 46 calculates a PWM (pulse width modulation) value that determines the torque of the motor 50 according to the light amount control signal, and the motor driver 51 drives the motor 50 by generating a drive pulse corresponding to the PWM value. The PWM value determines the duty ratio of the drive pulse of the motor 50 (value obtained by dividing the pulse width by the pulse period), and determines the torque of the motor 50. When the light amount control signal is a signal requesting an increase in the light amount of the emitted light L _out , the CPU 46 increases the PWM value according to the increase, and the light amount control signal requests a decrease in the light amount of the emitted light L _out. If it is a signal, the PWM value is lowered according to the decrease.

The diaphragm adjusting mechanism 49 includes a diaphragm blade 58 that opens and closes the diaphragm opening 57 and a spring 59 that biases the diaphragm blade 58 to a position where the diaphragm opening 57 is closed. The diaphragm blade 58 rotates in a direction (for example, clockwise) in which the aperture amount of the aperture opening 57 increases against the urging force of the spring 59 due to the torque applied from the motor 50. Stop at a position where the forces are balanced. When the torque is large, the force against the urging force of the spring 59 is also increased, so that the opening amount of the aperture opening 57 is also increased. When the torque is small, the force against the urging force of the spring 59 is small, so the opening amount of the aperture opening 57 is small. The torque of the motor 50 increases as the PWM value increases, and decreases as the PWM value decreases.

Such aperture of the light amount control is carried out in accordance with the photometric value L _M, the state amount is large of the outgoing light L _out is also large temperature rise in the long-lasting and of the insertion portion 16 tip 16a. In order to suppress this temperature rise, the electronic endoscope system 11 restricts the upper limit value of the light amount control range of the emitted light _Lout , thereby suppressing the temperature rise of the distal end 16a of the insertion portion 16. M1 and the second restriction mode M2 are provided.

As shown in FIG. 4, the normal mode M0 is a mode that is set when the light source device 14 is activated, and the upper limit value of the opening that indicates the opening amount of the aperture opening 57 as a percentage is 100%, for example, the output light L _out . The upper limit Lx of the light quantity is set to L0 [lm: lumen]. The PWM value for setting this upper limit value L0 [lm] is P0. The upper limit value L0 [lm] of the light amount of the emitted light _Lout is the upper limit value of the light amount control range in the normal mode M0. The upper limit of the amount of light control range in the first limitation mode M1 is lower than the normal mode M0, for example, the upper limit value of the degree of opening of the aperture stop 57 is 70%, the upper limit value Lx of the light quantity of the outgoing light _{L out} is L1 [lm ] (<L0 [lm]), and the PWM value for setting the upper limit L1 [lm] is P1. The upper limit of the amount of light control range in the second limit mode M2 is further lower than the first limitation mode M1, the upper limit is 25% of the aperture size of the diaphragm aperture 57, the upper limit value Lx of the light quantity of the outgoing light _{L out} is L2 [ lm] (<L1 [lm]), and the PWM value for setting the upper limit L2 [lm] is P2. Here, L2 only needs to be such that it can be confirmed whether or not the tip 16a is lit during standby.

In the first restriction mode M1 and the second restriction mode M2, the light amount control by the diaphragm is performed within the ranges of the upper limit values L1 [lm] and L2 [lm], respectively. That is, in the first limitation mode M1 and the second limitation mode M2, and the light quantity control unit 53 detects the insufficient light amount of incident light _{L in,} requesting an increase in the quantity of emitted light _{L out} against CPU46 of the light source device 14 Even if the light quantity control signal to be transmitted is transmitted, if the light quantity of the emitted light L _out has already reached the upper limit values L1 [lm] and L2 [lm], the CPU 46 does not further increase the PWM value. not raise the amount of light of the Shako _{L out.} Thus, the first limitation mode M1 and the second limitation mode M2, the upper limit value Lx of the light quantity of the outgoing light _{L out} is the upper limit value L0 [lm] lower than the upper limit L1 of the normal mode M0 [lm], L2 Since it is limited to [lm], the temperature rise of the distal end 16a of the insertion portion 16 is suppressed. Switching from the normal mode M0 to the first restriction mode M1 and from the normal mode M0 to the second restriction mode M2 is performed based on whether or not the insertion portion 16 is inserted into the body cavity and the temperature of the distal end 16a. Is called.

Insertion determining unit 54 shown in FIG. 3, in the normal mode M0, the state in which the light quantity of the outgoing light L _out is irradiated with the upper limit value L0 [lm] is a predetermined time (for example, 30s) that are set in advance was continued Sometimes, it is determined that the insertion unit 16 is in the standby state S1 in which it is not inserted into the body cavity. In the standby state S1 in which the insertion portion 16 is not inserted into the body cavity, because the observation region in the vicinity of the tip 16a of the entrance window 28 is provided is not present, in the light quantity upper limit value L0 of the outgoing light L _out [lm] even if they are irradiated, the photometric value L _M does not reach the reference value L _S. In this state, the light amount control unit 53 continues to request the CPU 46 of the light source device 14 to increase the light amount of the emitted light L _out , so that the necessary light amount gradually increases. As a result, the light quantity of the outgoing light _{L out} reaches the upper limit value L0 [lm].

The insertion determination unit 54 sequentially acquires the PWM value representing the light amount of the emitted light L _out from the CPU 46, and measures the time during which the state where the upper limit value Px of the PWM value is P0 continues with the system timer. When the state where the upper limit value Px of the PWM value is P0 continues for a predetermined time, the insertion determination unit 54 is in a state where the insertion unit 16 is not inserted into the body cavity, that is, a state where the insertion unit 16 is outside the body cavity. It is determined that it is S1 (hereinafter referred to as a standby state).

Further, insertion determining unit 54, the second limitation mode M2, when the required amount of light quantity control unit 53 requests the CPU46 on the basis of the photometric value _{L M} becomes the upper limit value smaller than L0 [lm], insert It is determined that the part 16 is in the state S2 inserted into the body cavity. In the insertion state S2 in which the insertion portion 16 is inserted into the body cavity, the observation part (inner wall of the duct) exists in the vicinity of the distal end 16a where the incident window 28 is provided, so that the emitted light L _out reflected at the observation part is incident light. a L _in is incident on the CCD30. Therefore, if the upper limit value Lx is constant, the photometric value L _M of the insertion state S2 is larger than that of the standby state S1, exceeds described later light amount threshold. The light amount threshold value is stored in, for example, a built-in memory of the light source device 14 and can be read by the CPU 46. As a result, in the insertion state S2, the required light amount requested by the light amount control unit 53 to the CPU 46 is less than the upper limit value L0 [lm] of the light amount in the normal mode M0. The insertion determination unit 54 inputs the determination result thus determined (whether the insertion unit 16 is in the standby state S1 or the insertion state S2) to the temperature suppression unit 56.

The temperature determination unit 55 has a difference (hereinafter, abbreviated as a temperature difference) ΔT [° C.] from a reference value of the temperature T [° C.] detected by the temperature sensor 33 exceeding a preset threshold value T1 [° C.]. It is determined whether or not. Here, the reference value of the temperature T [° C.] detected by the temperature sensor 33 is, for example, a value when the power of the electronic endoscope system 11 is turned on, and the temperature when the power is turned on. When T is 20 ° C. and the current temperature T is 30 ° C., the temperature difference ΔT is 10 ° C.

Based on the determination result from the insertion determination unit 54 and the determination result from the temperature determination unit 55, the temperature suppression unit 56 determines whether or not to shift from the normal mode M0 to the first restriction mode M1 and the second restriction mode M2. The mode switching signal is transmitted to the CPU 46 of the light source device 14.

When the insertion portion 16 is inserted into the body cavity and the temperature difference ΔT [° C.] exceeds the preset threshold value T1 [° C.], the temperature suppression unit 56 starts from the normal mode M0 to the first restriction mode. A first mode switching signal for switching to M1 is input to the CPU 46 of the light source device 14.

When it is determined that the insertion unit 16 is not inserted into the body cavity, the temperature suppression unit 56 inputs a second mode switching signal for switching from the normal mode M0 to the second restriction mode M2 to the CPU 46 of the light source device 14.

After it is determined that the insertion portion 16 is not inserted into the body cavity, that is, when it is determined that the insertion portion 16 is in the insertion state S2 during the second restriction mode M2, the temperature suppression unit 56 performs the second restriction mode. A release signal for releasing M2 and returning to the normal mode M0 is input to the CPU 46 of the light source device 14.

The CPU 46 of the light source device 14 switches from the normal mode M0 to the first limit mode M1 when the first mode switching signal is input from the processor device 13, and from the normal mode M0 when the second mode switching signal is input. Switch to the second restriction mode M2. In addition, in the second restriction mode M2, when a release signal is input from the processor device 13, the second restriction mode M2 is released and the normal mode M0 is restored. On the other hand, the first restriction mode M1 cannot be released by manual operation while the insertion portion 16 is inserted. Each mode M0 to M2 is notified by lighting or blinking of the monitor lamp 21.

With reference to the graph of FIG. 5, the normal mode M0, first limitation mode M1, and an example of a change in the upper limit value Lx and the temperature difference ΔT of the light quantity of the outgoing light L _out when the transition between the second limitation mode M2 explain. The mode transition example in FIG. 5B assumes the following sequence. First, at time t0 [s], when the power source of the light source device 14 to which the electronic endoscope 12 is connected is turned _on (U _on ), the light source device 14 is in the normal mode M0 (the upper limit Lx of the light amount is L0 [ lm])). Next, when a predetermined time (for example, 30 s) elapses while the electronic endoscope 12 is on standby (U _out ), it is determined that the insertion portion 16 is not inserted into the body cavity, and the time t1 [s]. The process proceeds to the second restriction mode M2 (the upper limit value Lx of the light amount is L2 [lm]). When examination by an endoscope is started at time t2 [s] and it is determined that the insertion portion 16 is in the insertion state S2 inserted into the body cavity (U _insert ), the normal mode M0 is restored from the second restriction mode M2. . Then, at time t3 [s], when the temperature difference ΔT [° C.] exceeds the threshold T1 [° C.], the normal mode M0 changes to the first limit mode M1 (the upper limit Lx of the light amount is L1 [lm]). Transition.

As shown in FIG. 5B, in each mode of the above-described sequence, the light amount of the emitted light L _out is the upper limit value L0 [lm], L1 [lm], L2 [lm], that is, the maximum light amount in each mode. When the irradiation continues, the temperature difference ΔT [° C.] changes as shown in FIG. That is, since it is the normal mode M0 at the time of activation, if the light source 47 continues to irradiate with the maximum light amount (upper limit value L0 [lm]) of the normal mode M0, the temperature difference ΔT [° C.] increases monotonously. When this state continues, the temperature difference ΔT exceeds the limit value T3 at which the electronic endoscope system 11 functions normally, as indicated by the two-dot chain line Lk1. Therefore, temperature control that suppresses an increase in the temperature difference ΔT is performed.

When the light source device 14 shifts to the second limit mode M2 at time t1 [s], the upper limit value Px of the PWM value decreases from the upper limit value P0 of the normal mode M0 to the upper limit value P2 of the second limit mode M2. For this reason, the upper limit Lx of the amount of light decreases from L0 [lm] to L2 [lm]. In the second restriction mode M2, the maximum light amount (upper limit value L2 [lm]) is lower than that in the normal mode M0. Therefore, even if irradiation is continued at the maximum light amount (upper limit value L2 [lm]), the temperature rise gradient The temperature difference ΔT [° C.] converges to T5 [° C.].

When the insertion section 16 is inserted into the body cavity at time t2 [s] (U _insert ), an observation site is present in the vicinity of the distal end 16a where the incident window 28 is provided. Therefore, when the insertion portion 16 is an upper limit value Lx of the light amount is changed from the left standby state S1 of L2 to the insertion state S2, the photometric value L _M exceeds the light amount threshold. Here, the light amount threshold, the insertion portion 16 is in a standby state S1, a photometric value L _M when the upper limit value Lx of the light amount is L2. As a result, the necessary light quantity becomes the upper limit Lx of the normal mode M0, that is, less than L0. Thus, the insertion determination unit 54 determines that the insertion unit 16 is in the insertion state S2 inserted into the body cavity, and inputs a release signal to the light source device 14. The CPU 46 releases the second restriction mode M2 and returns to the normal mode M0. When returning to the normal mode M0, the upper limit Lx of the light amount increases from L2 [lm] to L0 [lm]. When irradiation is continued with the maximum light amount (upper limit L0 [lm]) in the normal mode M0, the temperature difference ΔT [° C.] increases monotonously beyond the convergence value T5 [° C.] in the second limit mode M2. If this state continues, the limit value T3 is exceeded as indicated by a two-dot chain line Lk2. Therefore, when the temperature difference ΔT [° C.] exceeds the threshold T1 [° C.] at time t3 [s], the normal mode M0 is shifted to the first limit mode M1. As a result, the upper limit value Lx of the light amount decreases from L0 [lm] to L1 [lm]. When the upper limit value Lx of the light quantity decreases to L1 [lm], even if irradiation is continued with the maximum light quantity (upper limit value L1 [lm]), the gradient of temperature rise becomes gentle, and the temperature difference ΔT [° C.] becomes T2 [ [° C].

The convergence value T2 [° C.] of the temperature difference ΔT [° C.] in the first limit mode M1 needs to be equal to or less than the limit value T3 [° C.] at which the electronic endoscope system 11 functions normally. Since the convergence value T2 [° C.] is determined by the upper limit value L1 [lm] of the first limit mode M1, the upper limit value L1 [lm] is set so that the convergence value T2 [° C.] does not exceed the limit value T3 [° C.]. Is done. Even if there is a detection error, the upper limit value is set so that T2 [° C] is separated from T3 [° C] by a predetermined temperature so that the temperature difference ΔT [° C] does not exceed the limit value T3 [° C]. It is preferable to set L1 [lm].

Also, the threshold value T1 [° C.] needs to be separated from T2 [° C.] by a predetermined temperature. Otherwise, the temperature determination unit 55 determines that the temperature difference ΔT [° C.] has exceeded the threshold value T1 [° C.] until the light source device 14 is switched to the first limit mode M1. This is because the temperature difference ΔT [° C.] may once exceed T2 [° C.]. As specific values, when T3 is 20 ° C., T2 is set to 15 ° C. and T1 is set to 13 ° C.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG. As preparation work for endoscopy by the electronic endoscope system 11, the electronic endoscope 12 is connected to the processor device 13 and the light source device 14, and the power of the electronic endoscope system 11 is turned on (step ( Hereinafter, abbreviated as S.) 11). The light source device 14 is activated in the normal mode M0 (the upper limit value Lx of the light amount is L0 [lm]).

Information about the patient (patient name, patient ID, etc.) is input to the processor device 13 from the operation unit 42. During the preparatory work, the electronic endoscope 12 is placed on a hanger of a cart in which the processor device 13 and the light source device 14 are accommodated and is on standby. Since the light source device 14 is turned on and the light source 47 is lit, the electronic endoscope 12 emits the emitted light L _out from the distal end 16a even during standby. When the power is turned on, the insertion determination unit 54 starts determination processing (S12).

During standby, there is no observation site near the tip 16a. For this reason, most of the incident light L _in during standby is reflected light from an object (such as a floor) far away from the tip 16a, and thus the photometric value L _M is smaller than the reference value L _S. Light quantity control unit 53 sends a light amount control signal for requesting an increase in the quantity of emitted light L _out with respect to the light source device 14. The CPU 46 calculates a PWM value corresponding to the light amount control signal, and controls the aperture adjustment mechanism 49 through the motor driver 51 to increase the light amount of the emitted light L _out . However, the waiting, the light quantity of the incident light _{L in} the light quantity of the outgoing light _{L out} is incident on the upper limit value L0 [lm] Any CCD 30, i.e. photometric value _{L M} does not reach the reference value _{L S.} Therefore, the light amount control unit 53 continues to request the CPU 46 to increase the light amount, and the CPU 46 continues to output the upper limit value P0 of the PWM value. This PWM value is input to the insertion determination unit 54. The insertion determination unit 54 monitors the PWM value, and when the state where the upper limit value Lx of the PWM value is P0 continues for a predetermined time (for example, 30 seconds), the insertion determination unit 54 determines that the standby state S1 in which the insertion unit 16 is not inserted (S1). NO at S12).

When the insertion determination unit 54 determines that the standby state S1 is in effect, the temperature suppression unit 56 transmits a second mode switching signal for switching from the normal mode M0 to the second restriction mode M2 to the CPU 46. CPU46 receives the second mode switching signal, the upper limit value Px of the PWM value is changed to P2, lower the upper limit value Lx of the light quantity of the outgoing light _{L out} to L2 [lm] (S13). For this reason, as shown to FIG. 5 (A), the temperature of the front-end | tip 16a converges by T5 [degreeC], and a temperature rise is suppressed. Moreover, useless heat generation can be suppressed.

When the examination is started, the electronic endoscope 12 is removed from the hanger, and the insertion portion 16 is inserted into the body cavity. Since the temperature of the tip 16a is suppressed to T5 [° C.] at the start of insertion, the burden on the subject is small. The emitted light L _out supplied from the light source device 14 is irradiated to the body cavity, and an image by the CCD 30 is displayed on the monitor 15.

When the insertion portion 16 is inserted into the body cavity, due to the presence of the observation portion (such as a tube passage inner wall) is in the vicinity of the tip 16a, with even light intensity of the outgoing light L _out is constant, increase amount of the incident light L _in incident to CCD30 To do. As a result, the required light amount requested by the light amount control unit 53 to the CPU 46 is less than the upper limit value L0 [lm] of the normal mode M0. The insertion determination unit 54 monitors the necessary light amount requested by the light amount control unit 53 to the CPU 46 (S14), and when the necessary light amount becomes less than the upper limit L0 [lm], the insertion unit 16 is inserted. Determine (YES in S14).

If it is determined that the insertion unit 16 is in the insertion state S2 inserted into the body cavity, the temperature suppression unit 56 inputs a release signal to the CPU 46 of the light source device 14. When the cancel signal is input, the CPU 46 cancels the second limit mode M2 and returns to the normal mode M0, and increases the upper limit Lx of the light amount from L2 [lm] to L0 [lm] (S15).

After determining that the insertion unit 16 is in the insertion state S2 (YES in S12, YES in S14), the temperature determination unit 55 sequentially determines whether or not the temperature difference ΔT [° C.] exceeds the threshold value T1 [° C.]. (S16). When it is determined that the temperature difference ΔT [° C.] exceeds the threshold value T1 [° C.] (YES in S16), the first mode switching signal is input to the CPU 46 of the light source device 14. In response to the input of the first mode switching signal, the CPU 46 switches from the normal mode M0 to the first limiting mode M1, and lowers the light amount upper limit Lx from L0 [lm] to L1 [lm] (S17).

In the first embodiment, when the light amount is adjusted in the normal mode M0 where the upper limit value of the light amount is L0 [lm] and the insertion portion 16 is not inserted into the body cavity, the upper limit value Lx of the light amount is L0 from the normal mode M0. Since the transition is made to the second restriction mode M2 of L2 [lm] smaller than L1, the temperature rise at the distal end 16a of the insertion portion 16 can be suppressed while preparing to insert the insertion portion 16 into the body cavity. .

Further, when the light quantity is adjusted in the second restriction mode M2, when it is determined that the insertion portion 16 has been inserted into the body cavity, the second restriction mode M2 is automatically canceled and the normal mode M0 is entered. Since the amount of light is adjusted, there is no need to manually release the second restriction mode M2, and this is convenient. If the operator does not have an automatic release function, the operator may forget to release it and the image displayed on the monitor 15 will remain dark, which may cause a misunderstanding that a failure or malfunction has occurred. There is no such inconvenience.

Furthermore, when the insertion portion 16 is inserted into the body cavity, the temperature difference ΔT [° C.] at the distal end 16a of the insertion portion 16 exceeds the preset threshold value T1 [° C.] from the normal mode M0. Switching to the 1 limit mode M1 and lowering the upper limit value Lx of the light amount from L0 [lm] to L1 [lm] prevents the distal end 16a of the insertion portion 16 from reaching the limit value T3 [° C.]. The upper limit value L1 [lm] in the first limit mode M1 is closer to the upper limit value L0 [lm] in the normal mode M0 than the upper limit value L2 [lm] in the second limit mode M2. Therefore, even if the first restriction mode M1 is shifted during observation, the brightness of the image is relatively close to that of the normal mode M0 and does not become extremely dark. Absent.

[Second Embodiment]
In the electronic endoscope system 11 of the first embodiment, when the normal mode M0 is switched to the first limiting mode M1, the upper limit value Lx of the light amount is lowered in one step from L0 [lm] to L1 [lm] (FIG. 5). (See (B)). For this reason, when the irradiation is performed with the maximum light amount in the normal mode M0, when the mode is switched to the first restriction mode M1, the light amount suddenly decreases from L0 [lm] to L1 [lm]. When the amount of light suddenly decreases, the image displayed on the monitor 15 suddenly becomes dark. As a result, the surgeon may misunderstand that a failure or malfunction has occurred.

Therefore, in the second embodiment described below, the image displayed on the monitor 15 is prevented from suddenly becoming dark. In addition, the structure employ | adopted by the said 1st Embodiment and each embodiment shown after this shall be applied mutually in the possible range. In the second embodiment, the description of the same configuration, operation, and effect as in the first embodiment is omitted. Moreover, in each embodiment after 3rd Embodiment, only a different point from other embodiment is demonstrated.

In the second embodiment, the temperature determination unit 55 sequentially inputs the temperature difference ΔT [° C.] to the CPU 46 of the light source device 14 when the temperature difference ΔT [° C.] exceeds the threshold T1 [° C.].

As shown in FIGS. 7A and 7B, the CPU 46 receives the temperature difference ΔT [°] when the temperature difference ΔT [° C.] exceeds the threshold T1 [° C.] and the first mode switching signal is input from the processor device 13. When the upper limit value (Px) of the PWM value is decreased from the maximum value P0 to P1 with the increase in [° C.], it is gradually decreased in a continuous or stepwise manner. Regardless of the increase in the temperature difference ΔT [° C.], the CPU 46 continuously increases the PWM upper limit value (Px) from the maximum value P0 to P1 when the first mode switching signal is input. Or you may reduce gradually in steps. The upper limit value (Lx) of the light amount gradually decreases from L0 [lm] to L1 [lm] over a predetermined time Δt [s]. The image displayed on the monitor 15 is gradually darkened over a predetermined time Δt [s].

As described above, in the second embodiment, since the upper limit value of the light amount is gently lowered from L0 [lm] to L1 [lm], the image displayed on the monitor 15 does not suddenly become dark, It is possible to prevent misidentification that a defect has occurred.

[Third Embodiment]
In the third embodiment described below, the temperature is estimated based on the history information of the light amount control, instead of directly detecting the temperature by providing the tip 16a with a temperature sensor. Specifically, the temperature is indirectly detected by obtaining the temperature difference ΔT [° C.] by calculation based on the history information of the PWM value representing the transition of the light amount change in the light amount control.

The temperature determination unit 55 performs a calculation using the history information of the PWM value input from the light source device 14 and virtually calculates the temperature difference ΔT [° C.]. The temperature difference ΔT [° C.] is expressed as follows: ΔT = Q / C · where the amount of heat applied to the tip 16a of the insertion portion 16 is Q [mJ] and the heat capacity at the tip 16a of the insertion portion 16 is C [mJ / ° C.]. .. (Equation 1) The heat capacity C [mJ / ° C.] is a value inherent to the electronic endoscope 12 and is, for example, 800 mJ / ° C.

The temperature difference ΔT _n [° C.] up to the present time is added to the tip 16a of the insertion portion 16 at the immediately preceding dt [s] time, with the rising value until dt [s] time being ΔT _n-1 [° C.]. When the heat quantity is dQ [mJ], ΔT _n = ΔT _n-1 + dQ / C (Expression 2). The time dt [s] is, for example, 1.0 s. The initial value of the temperature difference ΔT [° C.] is 0.0 ° C.

The calorific value dQ [mJ] is defined as q [mW (= mJ / s)] as the calorific value per unit time due to the light supplied from the light source device 14, and sq [mW] as the calorific value per unit time from the CCD 30. If the thermal resistance at the distal end 16a of the insertion portion 16 is R [° C./mW], the calorific value is expressed as follows: dQ = (q + sq) × dt−ΔT _n−1 × dt / R (Equation 3) It is indicated by heat dissipation.

The thermal resistance R [° C./mW] is a value inherent to the electronic endoscope 12 and is, for example, 0.2 ° C./mW. The calorific value q [mW] is expressed as (PWM value that determines the amount of light) × (proportional constant kq). The proportionality constant kq is a value unique to the electronic endoscope 12 and the light source device 14. For the PWM value, an average value of values at each time obtained by dividing the time dt [s] into n (for example, 10) is used in order to improve calculation accuracy. The calorific value sq [mW] is a value unique to the CCD, for example, 100 mW.

Substituting Equation 3 into Equation 2 above, the temperature difference ΔT _n [° C.] up to the present time can be expressed as ΔT _n = ΔT _n-1 + (q + sq) × dt / C−ΔT _n−1 × dt / (C × R ) (Expression 4). The temperature determination unit 55 obtains the temperature difference ΔT _n [° C.] up to the present time using the above equation 4. That is, as shown in FIG. 8, the temperature determining unit 55, with respect to dt [s] Temperature difference ΔT _n-1 [℃] up to the time before, the heat radiation temperature represented by a function of ΔT _n-1 [℃] The temperature difference ΔT _n [° C.] up to the present time is determined by adding the heat generation temperature indicated by the function of the heat generation amount q [mW] per unit time due to the light supplied from the light source device 14.

The parameters C [mJ / ° C.], sq [mW], R [° C./mW], and kq depending on the model of the electronic endoscope 12 are non-volatiles built into the electronic endoscope 12 at the time of factory shipment. It is stored in advance in a memory (for example, an EEPROM), and is automatically acquired when the power of the electronic endoscope system 11 is turned on and used for calculation. Alternatively, it is associated with a model-specific ID and stored in advance in a nonvolatile memory built in the processor device 13. A model-specific ID is stored in the nonvolatile memory built in the electronic endoscope 12, and each parameter corresponding to the ID read from the nonvolatile memory of the electronic endoscope 12 is used for calculation. Alternatively, it is associated with a model-specific ID and stored in advance in a server connected via a network or the like. In this case, each parameter corresponding to the ID read from the nonvolatile memory of the electronic endoscope 12 is acquired from the server and used for the calculation.

The temperature determination unit 55 determines whether or not the obtained temperature difference ΔT _n [° C.] exceeds a preset threshold T 1 [° C.].

Next, the operation of the above configuration will be described. As shown in FIG. 9, S31 to S35 are the same as S11 to S15. After determining that the insertion unit 16 has been inserted into the body cavity (YES in S32, YES in S34), the temperature determination unit 55 sequentially obtains the temperature difference ΔT _n [° C.] (S36). Then, when it is determined that the temperature difference ΔT _n [° C.] has exceeded the threshold T 1 [° C.] (YES in S 37), the first mode switching signal is input to the CPU 46 of the light source device 14. In response to the input of the first mode switching signal, the CPU 46 switches from the normal mode M0 to the first limit mode M1, and lowers the light amount upper limit Lx from L0 [lm] to L1 [lm] (S38).

As described above, in the third embodiment, since the temperature difference ΔT [° C.] of the temperature at the distal end 16a of the insertion portion 16 is virtually obtained, the temperature of the distal end 16a of the insertion portion 16 is not limited without a temperature sensor. It is prevented that the value T3 [° C.] is exceeded.

[Fourth Embodiment]
In the third embodiment, the temperature difference ΔT [° C.] is obtained in detail by using values such as the heat capacity C [mJ / ° C.] and the thermal resistance R [° C./mW] at the tip 16a of the insertion portion 16, In the fourth embodiment to be described next, the integrated value [lm · s] of the light amount L [lm] is obtained by a simple calculation, and it is handled that the temperature difference ΔT [° C.] is obtained.

In the fourth embodiment, the temperature determination unit 55 performs a calculation using the history information of the PWM value input from the light source device 14, and the light amount L from the light source device 14 at a predetermined time ts [s] (for example, 30 s). An integrated value [lm · s] of _N [lm] is obtained. The light quantity _LN is expressed as (PWM value) × kl. The proportionality constant kl is a value unique to the electronic endoscope 12 and the light source device 14. The temperature determination unit 55 calculates the integrated value [lm · s] of the light amount L _N [lm] up to the present time by integrating the PWM value multiplied by the proportionality constant kl. The temperature determination unit 55 determines whether or not the obtained integrated value [lm · s] exceeds a preset threshold value [lm · s].

The temperature suppression unit 56 is a first mode for switching from the normal mode M0 to the first limit mode M1 when the temperature determination unit 55 determines that the integrated value [lm · s] of the light amount L _N [lm] exceeds the threshold value. A switching signal is input to the light source device 14.

As shown in FIG. 10, when the integrated value [lm · s] (value indicated by the hatched area) of the light amount L _N [lm] at a predetermined time ts [s] exceeds the threshold value, the processor device 13. The first mode switching signal is input to the light source device 14.

Next, the operation of the above configuration will be described. As shown in FIG. 11, S41 to S45 are the same as S31 to S35. After determining that the insertion unit 16 has been inserted into the body cavity (YES in S42, YES in S44), the temperature determination unit 55 determines the amount of light L _N [lm from the light source device 14 at a predetermined time ts [s]. ] Is sequentially obtained (S46). Then, it is determined whether or not the integrated value [lm · s] of the light amount L _N [lm] exceeds a threshold value (S47). When it is determined that the integrated value [lm · s] of the light amount L _N [lm] exceeds the threshold (YES in S47), the first mode switching signal is input from the temperature suppression unit 56 to the CPU 46 of the light source device 14. . S48 is the same as S38.

[Fifth Embodiment]
By the way, the older the history information of the amount of light, the smaller the influence on the temperature at the distal end 16a of the insertion portion 16. Therefore, in the fifth embodiment described below, the integrated value [lm · s] of the light amount L _N [lm] at the predetermined time ts [s] is obtained by weighted calculation in which the older history information is made smaller in weight. This is different from the fourth embodiment.

In the fifth embodiment, the temperature determination unit 55 integrates a value obtained by multiplying the PWM value by a proportional constant kl with a smaller weight added to older history information, thereby integrating the light amount L _N [lm] up to the present time. [Lm · s] is obtained. For example, when weighting is performed by dividing the predetermined time ts [s] into three, the weights are multiplied by 1.0, 0.9, and 0.8 sequentially from the new history information.

As shown in FIG. 12, when it is determined that the weighted integrated value [lm · s] (a value obtained by multiplying the area of each portion indicated by hatching by each weight) exceeds a threshold value at a predetermined time ts [s]. The first mode switching signal is input to the light source device 14.

As described above, in the fifth embodiment, the older history information having a smaller influence on temperature has a smaller weight, and the integrated value [lm · s] of the light amount L _N [lm] is obtained. It can prevent more correctly that the front-end | tip 16a of the insertion part 16 exceeds limit value T3 [degreeC].

[Sixth Embodiment]
In each of the above embodiments, the light source 47 that is turned on with a substantially constant light amount is provided, and the aperture adjustment mechanism 49 adjusts the aperture amount of the aperture opening 57 disposed on the optical path of the light from the light source 47, thereby outputting the emitted light L. _{Although the out} light quantity is controlled, a light source capable of controlling the light emission amount of the light source itself may be provided instead.

For example, as shown in FIG. 13, an LED 61 that emits outgoing light L _out is built in the distal end 16 a of the insertion portion 16 of the electronic endoscope 12. The CPU 46 controls the light emission amount [lm] of the LED 61 through the light source driver 48. The CPU 46 changes the upper limit value of the light amount control range by the light amount control unit 53 based on the mode switching signal from the temperature suppression unit 56. In FIG. 13, the LED 61 is disposed at the distal end 16a of the insertion portion 16, but the LED 61 may be disposed at the light source device 14 and guided to the distal end 16a by an optical fiber. Further, the light source may be a light source that emits white light by exciting the phosphor by making the excitation light incident on the phosphor.

In each of the above embodiments, a release function is not provided so that the first restriction mode M1 is not carelessly released, but on condition that the temperature difference ΔT [° C.] does not exceed T2 [° C.], that is, The temperature difference ΔT [° C.] may be canceled on the condition that the temperature difference ΔT [° C.] has dropped below T1 [° C.].

However, when the first restriction mode M1 is canceled at the moment when the temperature difference ΔT [° C.] falls below T1 [° C.], the temperature difference ΔT [° C.] immediately exceeds T1 [° C.] immediately after that, and the first restriction immediately follows. There is a risk of returning to the mode M1. For this reason, the first limit mode M1 can be canceled on the condition that the temperature difference ΔT [° C.] has dropped below the preset temperature [° C.] by a predetermined temperature from T1 [° C.]. It is preferable. The first restriction mode M1 may be automatically released when the release condition is satisfied, or the first restriction mode M1 may be released when an appropriately set additional condition is satisfied in addition to the release condition. Good. For example, when the additional condition is “when a release button provided on the operation unit 17 of the electronic endoscope 12 is pressed”, the first restriction mode M1 can be manually released.

In each of the above embodiments, when the first restriction mode M1 is canceled, the relationship between the temperature difference ΔT [° C.] shown in FIG. 7A and the upper limit value (Px) of the PWM value that determines the amount of light is used. As the temperature difference ΔT [° C.] decreases, the PWM value may be gradually increased from P1 to the maximum value P0 continuously or stepwise. According to such a configuration, the increase in the upper limit Lx of the light amount due to the cancellation of the first restriction mode M1 can be moderated, so that the image displayed on the monitor 15 does not suddenly become bright.

In each of the above-described embodiments, the first restriction depends on the types of the electronic endoscope 12, the processor device 13, and the light source device 14 that constitute the electronic endoscope system 11, and the combinations of the configurations 12, 13, and 14. The function of the mode M1 or the second restriction mode M2 may be stopped.

Further, in each of the embodiments described above, the insertion determination unit 54 determines that the insertion unit 16 determines that the state in which the upper limit value Lx of the light amount is the maximum value L0 [lm] in the normal mode M0 continues for a preset predetermined time. It is determined that the insertion unit 16 is inserted into the body cavity when it is determined that the insertion unit 16 has not been inserted into the body cavity, and the required light amount requested by the light amount control unit 53 in the second restriction mode M2 is less than the upper limit L0 [lm]. Although it determined, the determination method is not limited to this. For example, the determination may be made based on the temperature change at the tip when moving from the outside of the body cavity (outside the subject) to the inside of the body cavity, or by image analysis. The image analysis method is a method of analyzing an image captured by the imaging apparatus and determining whether the image is a body cavity image or an image outside the body cavity. Or you may determine by the detection of the mouthpiece used at the time of a test | inspection. In this case, for example, an RFID tag is embedded in the mouthpiece, and an RFID reader is provided at the distal end 16a of the insertion portion 16, and the determination is made based on whether radio waves are received from the RFID tag.

In each of the above embodiments, the second restriction mode M2 is automatically released when it is determined that the insertion unit 16 has been inserted into the body cavity, but a release button is provided on the operation unit 17 of the electronic endoscope 12. It may be possible to release it by manual operation.

In each of the above embodiments, when the mode is switched to the first limit mode M1, the upper limit Lx of the light amount is lower than that in the normal mode M0, so that the image displayed on the monitor 15 becomes dark and the operator feels uncomfortable. There is a risk of remembering. In order to correct this, a function of amplifying the imaging signal when switching to the first restriction mode M1 may be installed.

That is, when the mode is switched to the first restriction mode M1 and the upper limit value Lx of the light quantity is restricted from L0 [lm] to L1 [lm], the amplification factor A corresponding to the required light quantity L [lm] requested by the light quantity restriction unit 53 Is set in the DSP 39, and the imaging signal is amplified by the DSP 39. In this case, A = 1 when the required light quantity L [lm] is less than L1 [lm], A = L / L1 when the required light quantity L [lm] is greater than or equal to L1 [lm] and less than L0 [lm], and the required light quantity. When L [lm] is L0 [lm], A = L0 / L1 and an amplification factor are set so that the brightness of the image displayed on the monitor 15 is equal in both the normal mode M0 and the first limit mode M1. An image with less discomfort for the surgeon can be obtained. In addition, although the case where the digital imaging signal was amplified was mentioned as an example, you may make it the structure which amplifies an analog imaging signal.

Further, in each of the above embodiments, the first function is provided by temporarily releasing the upper limit of the light amount of the emitted light L _out when recording a still image (for example, by 1/60 s of the frame rate). A configuration in which a sufficient amount of the emitted light L _out is secured even under the restriction mode M1 to obtain a high-quality still image may be used. In this case, when the surgeon instructs to record a still image, the temperature rise when the upper limit of the light amount of the emitted light _Lout is temporarily released is temporarily released, and the calculation result is the limit value T3 [° C. ] May not be released, i.e., control may be performed to continue the upper limit restriction.

DESCRIPTION OF SYMBOLS 11 Electronic endoscope system 14 Light source device 16 Insertion part 16a Tip 33 Temperature sensor 36 CPU
49 Aperture adjustment mechanism 53 Light quantity control unit 54 Insertion determination unit 55 Temperature determination unit 56 Temperature suppression unit 61 LED

Claims

An endoscope having an emission part that emits outgoing light to the outside, an incident part where light from the outside is incident, and an insertion part provided at the tip with an imaging part that images incident light incident on the incident part;
A light amount control means for measuring the light amount of the incident light and controlling the light amount of the emitted light within a range of a preset upper limit value or less;
Temperature determination means for determining whether or not the temperature of the tip exceeds a preset temperature threshold;
Insertion determining means for determining whether the insertion portion is inserted into a body cavity or a standby state outside the body cavity;
When the insertion determination unit determines that the insertion portion is in the insertion state and the temperature determination unit determines that the temperature of the tip has exceeded the temperature threshold, the upper limit value is set at startup. When the insertion determination unit determines that the insertion unit is in the standby state, the upper limit value is set to a value L2 smaller than the value L1. An electronic endoscope system comprising: temperature suppression means for suppressing temperature rise at the tip by setting the upper limit value.
The said insertion determination means determines that the said insertion part is the said standby state, when the light quantity of the said emitted light continues for the predetermined time with the said upper limit L0, The range of Claim 1 characterized by the above-mentioned. Electronic endoscope system. *
The insertion determination unit determines that the insertion unit is in the insertion state when the light amount of the incident light measured by the light amount control unit exceeds a preset light amount threshold value. The electronic endoscope system according to claim 1 or 2.
When the upper limit value is set to the value L2, when the insertion determination unit determines that the insertion portion is in the insertion state, the temperature suppression unit changes the upper limit value from the value L2 to the value L0. The electronic endoscope system according to any one of claims 1 to 3, wherein the electronic endoscope system is automatically returned to a normal state.
After the upper limit value is set to the value L1, the temperature suppression unit prohibits a release operation for returning the upper limit value from the value L1 to the value L0 unless the temperature at the tip is equal to or lower than the temperature threshold value. The electronic endoscope system according to any one of claims 1 to 4, characterized in that:
The temperature determination unit performs a calculation using a light amount control history indicating a transition of a light amount change of the emitted light controlled by the light amount control unit, and the temperature of the tip exceeds the temperature threshold based on the calculation result. The electronic endoscope system according to any one of claims 1 to 5, wherein it is determined whether or not it has been.
7. The temperature determination unit according to claim 6, wherein the temperature determination unit obtains an estimated value of the current temperature of the tip using the light amount control history, and makes a determination by comparing the estimated value with the temperature threshold value. The electronic endoscope system described in 1.
The temperature determination means calculates the estimated value at regular time intervals, adds the temperature increase from the previous time to the current time based on the light amount control history to the calculated previous estimated value, The electronic endoscope system according to claim 7, wherein the estimated value for this time is obtained by subtracting a temperature decrease due to heat dissipation up to.
The electronic endoscope according to claim 6, wherein the temperature determination unit obtains an integrated value of the light amount of the emitted light based on the light amount control history, and determines based on the integrated value. system.
10. The electronic endoscope system according to claim 9, wherein the temperature determination means obtains the integrated value by decreasing a weight of an older one of the light amount control histories.
6. The temperature determination unit according to claim 1, wherein the temperature determination unit makes a determination by collating an actual measurement value measured by a temperature sensor provided at the tip with the temperature threshold value. Electronic endoscope system.
A light source that is lit with a substantially constant light amount, and an aperture adjustment mechanism that adjusts the light amount of the emitted light by adjusting the aperture amount of the aperture opening disposed on the optical path of the light emitted from the light source,
The electronic endoscope system according to any one of claims 1 to 11, wherein the temperature suppressing means limits the upper limit of the opening amount of the aperture adjustment mechanism by the value L1 and the value L2. .
It has a light source that can control the amount of light emitted.
The electronic endoscope system according to any one of claims 1 to 11, wherein the temperature suppression means limits an upper limit of the light emission amount of the light source by the value L1 and the value L2.