U.S. patent application number 13/545655 was filed with the patent office on 2013-01-31 for electronic endoscope apparatus and electronic endoscope system.
The applicant listed for this patent is Yasushi MATSUMARU. Invention is credited to Yasushi MATSUMARU.
Application Number | 20130030248 13/545655 |
Document ID | / |
Family ID | 47597762 |
Filed Date | 2013-01-31 |
United States Patent
Application |
20130030248 |
Kind Code |
A1 |
MATSUMARU; Yasushi |
January 31, 2013 |
ELECTRONIC ENDOSCOPE APPARATUS AND ELECTRONIC ENDOSCOPE SYSTEM
Abstract
Electric power of a required voltage is supplied to an endoscope
distal end portion, and a distal end temperature is prevented from
being higher. An imaging device having an imaging element, and its
peripheral circuit and a first circuit part including a first
regulator as a power circuit are built in the endoscope distal end
portion. The first circuit part is connected to a second circuit
part via a cable. The second circuit part includes a second
regulator supplying electric power to the first regulator. By the
overcurrent detection function of a temperature detecting unit or a
regulator arranged, when at least one abnormality of a temperature
abnormality and an overcurrent in the distal end portion is
detected, the output of at least one of the first regulator and the
second regulator is stopped, and supply of power to the distal end
portion is stopped.
Inventors: |
MATSUMARU; Yasushi;
(Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MATSUMARU; Yasushi |
Kanagawa |
|
JP |
|
|
Family ID: |
47597762 |
Appl. No.: |
13/545655 |
Filed: |
July 10, 2012 |
Current U.S.
Class: |
600/110 |
Current CPC
Class: |
A61B 1/00027 20130101;
A61B 1/00009 20130101; A61B 1/00011 20130101; A61B 1/128 20130101;
A61B 1/05 20130101; A61B 1/0676 20130101 |
Class at
Publication: |
600/110 |
International
Class: |
A61B 1/05 20060101
A61B001/05; A61B 1/06 20060101 A61B001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 26, 2011 |
JP |
P2011-163494 |
Claims
1. An electronic endoscope apparatus comprising: an imaging device
built in a distal end portion of an endoscope insertion part, and
having a solid-state imaging element that images a region to be
observed; a first regulator arranged within the distal end portion
along with the imaging device, and supplying electric power of a
required voltage to the imaging device; a cable including signal
lines that transmit signals obtained from the imaging device and a
power supply line that supplies electric power to the first
regulator; a second circuit part electrically connected to a first
circuit part including the imaging device and the first regulator
within the distal end portion, via the cable; a second regulator
mounted on the second circuit part and connected to the first
regulator via the power supply line; an abnormality detecting unit
that detects at least one abnormality of a temperature abnormality
and overcurrent in the distal end portion; and a power supply stop
unit that stops the output from at least one regulator of the first
regulator and the second regulator when an abnormality is detected
by the abnormality detecting unit.
2. The electronic endoscope apparatus according to claim 1, wherein
a temperature detecting unit is provided within the distal end
portion as the abnormality detecting unit.
3. The electronic endoscope apparatus according to claim 2, wherein
the second circuit part comprises a control circuit that controls
the operation of the second regulator, and wherein the control
circuit provides a control signal stopping the output of the second
regulator to the second regulator on the basis of a signal obtained
from the abnormality detecting unit, thereby cutting off the supply
of power from the second regulator,
4. The electronic endoscope apparatus according to claim 1, wherein
at least one of the first regulator and the second regulator is
provided with an overcurrent detecting circuit, and the overcurrent
detecting circuit is used as the abnormality detecting unit.
5. The electronic endoscope apparatus according to claim 2, wherein
at least one of the first regulator and the second regulator is
provided with an overcurrent detecting circuit, and the overcurrent
detecting circuit is used as the abnormality detecting unit.
6. The electronic endoscope apparatus according to claim 3, wherein
at least one of the first regulator and the second regulator is
provided with an overcurrent detecting circuit, and the overcurrent
detecting circuit is used as the abnormality detecting unit.
7. The electronic endoscope apparatus according to claim 4, wherein
the first regulator comprises the overcurrent detecting circuit,
and a self-shutdown circuit that stops output automatically when
overcurrent is detected, and wherein a self-shutdown circuit built
in the first regulator is used as the power supply stop unit.
8. The electronic endoscope apparatus according to claim 4, wherein
the second regulator comprises the overcurrent detecting circuit,
and a self-shutdown circuit that stops output automatically when
overcurrent is detected, and wherein a self-shutdown circuit built
in the second regulator is used as the power supply stop unit.
9. The electronic endoscope apparatus according to claim 4, wherein
the second circuit part comprises a control circuit that controls
the operation of the second regulator, wherein the second regulator
comprises the overcurrent detecting circuit, wherein a signal is
sent to the control circuit if overcurrent is detected by the
overcurrent detecting circuit, and wherein the control circuit
provides a control signal stopping the output of the second
regulator to the second regulator on the basis of the signal,
thereby cutting off the supply of power from the second
regulator.
10. The electronic endoscope apparatus according to claim 1,
wherein the second circuit part is arranged at a connector portion
formed at the end portion of the cable opposite to the first
circuit part.
11. The electronic endoscope apparatus according to claim 2,
wherein the second circuit part is arranged at a connector portion
formed at the end portion of the cable opposite to the first
circuit part.
12. The electronic endoscope apparatus according to claim 3,
wherein the second circuit part is arranged at a connector portion
formed at the end portion of the cable opposite to the first
circuit part.
13. The electronic endoscope apparatus according to claim 1,
further comprising a feedback circuit that returns an input
voltage, which is supplied to the first regulator via the power
supply line from the second regulator, to the second regulator.
14. The electronic endoscope apparatus according to claim 2,
further comprising a feedback circuit that returns an input
voltage, which is supplied to the first regulator via the power
supply line from the second regulator, to the second regulator.
15. The electronic endoscope apparatus according to claim 3,
further comprising a feedback circuit that returns an input
voltage, which is supplied to the first regulator via the power
supply line from the second regulator, to the second regulator.
16. The electronic endoscope apparatus according to claim 1,
wherein the solid-state imaging element is a CMOS type solid-state
imaging element.
17. The electronic endoscope apparatus according to claim 2,
wherein the solid-state imaging element is a CMOS type solid-state
imaging element.
18. The electronic endoscope apparatus according to claim 3,
wherein the solid-state imaging element is a CMOS type solid-state
imaging element.
19. An electronic endoscope system comprising: an electronic
endoscope apparatus having an imaging device, having a solid-state
imaging element that images a region to be observed, built in a
distal end portion of an endoscope insertion part; a processor
device that performs signal processing on imaging signals output
from the imaging device of the electronic endoscope apparatus; and
a light source for illumination that generates illumination light
to be irradiated to a region to be observed from an illumination
window provided at a distal end face of the endoscope insertion
part, wherein the electronic endoscope apparatus includes: a first
regulator arranged within the distal end portion along with the
imaging device, and supplying electric power of a required voltage
to the imaging device; a cable including signal lines that transmit
signals obtained from the imaging device and a power supply line
that supplies electric power to the first regulator; a second
circuit part electrically connected to a first circuit part
including the imaging device and the first regulator within the
distal end portion via the cable; a second regulator mounted on the
second circuit part and connected to the first regulator via the
power supply line; an abnormality detecting unit that detects at
least one abnormality of a temperature abnormality and an
overcurrent in the distal end portion; and a power supply stop unit
that stops the output from at least one regulator of the first
regulator and the second regulator when an abnormality is detected
by the abnormality detecting unit.
20. The electronic endoscope system according to claim 19, wherein
the second circuit part is arranged at a connector portion that
detachably couples the electronic endoscope to the light source for
illumination together.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an electronic endoscope
apparatus and an electronic endoscope system, and particularly, to
a management technique when an abnormality occurs in a distal end
portion of the electronic endoscope in which an imaging device
having a solid-state imaging element is built.
[0003] 2. Description of the Related Art
[0004] Electronic endoscope systems used in the medical field or
the like are constituted by an electronic endoscope (scope) in
which an imaging device including a solid-state imaging element is
provided at a distal end portion of an insertion part to be
inserted into a subject to be examined, and a processor device that
controls the operation of the imaging device, and performs various
kinds of signal processing on imaging signals output from the
imaging device to display an endoscope image on a monitor (display
device).
[0005] Inside the distal end of the endoscope insertion part,
temperature is apt to rise due to heat generation of the
solid-state imaging element, heat generation caused by the loss of
the light intensity of a light guide, or the like. If the internal
temperature of the endoscope insertion part rises, the noise of the
image signals increases and the image quality deteriorates.
Additionally, due to a failure of a circuit in the distal end
portion etc., overcurrent may flow and heat may be generated.
Moreover, if the image signals from the distal end portion are no
longer normally sent to the processor device, it is determined to
be a dark image, and a control is made in a direction in which an
iris (diaphragm mechanism) of a light source device is
automatically opened such that the exposure quantity that is
required is obtained. If a maximum quantity of light continues
being emitted with the iris opened, the distal end portion further
generates heat.
[0006] Since heat damage may be caused in a human body tissue if
the temperature of the endoscope distal end portion reaches a high
temperature, it is desired to maintain the temperature of the
distal end portion below a certain fixed temperature.
[0007] JP1995-194531A (JP-H07-194531) suggests an electronic
endoscope apparatus in which temperature detection means is
arranged near a solid-state imaging element provided at the distal
end of a scope, and when a temperature rise near the solid-state
imaging element is detected due to generation of an overcurrent,
the control of attenuating or cutting off supply of a driving
signal to the solid-state imaging element or waveform shaping means
is performed.
[0008] Additionally, a capsule endoscope disclosed in
JP2004-298241A includes temperature detection means that detects
internal temperature, and power source control means that performs
the control of stopping supply of power to an internal electric
circuit in a case where the internal temperature exceeds a
predetermined value.
SUMMARY OF THE INVENTION
[0009] A plurality of types of scopes, such as a scope for
observation of the stomach and a scope for observation of the small
intestine, exist corresponding to applications and observation
purposes in the electronic endoscope. Construction of systems that
can commonly use the same processor device and the same light
source device is desired for these various types of scopes. Wiring
lines used for the connection between the electronic endoscope and
the processor device are very thin (for example, AWG44 or the
like), and the wiring line length (the length of the cable) is
various depending on models. In a case where the influence of a
voltage drop caused by a wiring portion that connects the endoscope
distal end portion and the processor device is not negligible, and
the type of scope is changed, means (mechanism) for supplying
electric power of a required voltage to the scope distal end
portion is required.
[0010] Moreover, as already described, maintenance of the
temperature of the endoscope distal end portion below a certain
fixed temperature is also required. If electric power of a voltage
higher than needed is supplied to the endoscope distal end portion
in anticipation of the voltage drop caused by the wiring portion,
the amount of excess generates heat in the conversion to a
predetermined voltage. Accordingly, it is desirable to suppress
such excessive heat generation.
[0011] With respect to these problems, JP1995-194531A
(JP-H07-194531) and JP2004-298241A do not present specific
means(mechanism).
[0012] The present invention has been made in view of the
above-mentioned problems and an object of the present invention is
to provide an electronic endoscope apparatus and an electronic
endoscope system that, even in a case where the type of scope is
changed, can supply electric power of a required voltage to an
endoscope distal end portion, can suppress heat generation of the
distal end portion, and can prevent a distal end temperature from
reaching a temperature higher than an allowable temperature.
[0013] In order to achieve the above object, an electronic
endoscope apparatus of the invention includes: an imaging device
built in a distal end portion of an endoscope insertion part, and
having a solid-state imaging element that images a region to be
observed; a first regulator arranged within the distal end portion
along with the imaging device, and supplying electric power of a
required voltage to the imaging device; a cable including signal
lines that transmit signals obtained from the imaging device and a
power supply line that supplies electric power to the first
regulator; a second circuit part electrically connected to a first
circuit part including the imaging device and the first regulator
within the distal end portion via the cable; a second regulator
mounted on the second circuit part and connected to the first
regulator via the power supply line; an abnormality detecting unit
that detects at least one abnormality of a temperature abnormality
and an overcurrent in the distal end portion; and a power supply
stop unit that stops the output from at least one regulator of the
first regulator and the second regulator in a case where an
abnormality is detected by the abnormality detecting unit.
[0014] According to the present invention, the regulators are
respectively arranged at the first circuit part built in the
endoscope distal end portion and the second circuit part connected
to the first circuit part via the cable, and in a case where an
abnormality of the distal end portion is detected, output operation
of the first regulator or the second regulator or output operation
of both the regulators is stopped, and supply of power to the
imaging device of the distal end portion is stopped. This can
suppress heat generation of the distal end portion. By stopping
supply of power to the distal end portion by the abnormality
detection, the abnormal state does not last for a long time, and a
failure of an electronic circuit can be prevented.
[0015] Additionally, in the present invention, the regulators are
arranged at both the first circuit part and the second circuit
part, electric power is supplied to the regulator (first regulator)
of the first circuit part from the regulator (second regulator) of
the second circuit part, is converted into a voltage required of
the first regulator, and is used as a power source of the imaging
device. By adopting such a power supply system, electric power of a
predetermined voltage can be stably supplied to the first
regulator. In addition, the first regulator can output one type or
a plurality of types (two or more types) of predetermined
voltages.
[0016] A configuration is possible in which a temperature detecting
unit is provided within the distal end portion as the abnormality
detecting unit in the electronic endoscope apparatus of the present
invention. The temperature detecting unit can also be integrated in
the same semiconductor package as the imaging element, and can also
be configured in a separate package.
[0017] As an aspect of the present invention, a configuration can
be adopted in which the second circuit part includes a control
circuit that controls the operation of the second regulator, and
the control circuit provides a control signal stopping the output
of the second regulator to the second regulator on the basis of a
signal obtained from the abnormality detecting unit, thereby
cutting off the supply of power from the second regulator.
[0018] For example, a configuration can be adopted in which a CPU
(Central Processing Unit) is mounted on the second circuit part,
and an enable signal that switches the operation/non-operation of
the second regulator is given to the second regulator from the
CPU.
[0019] As another aspect of the present invention, a configuration
can be adopted in which at least one of the first regulator and the
second regulator is provided with an overcurrent detecting circuit,
and the overcurrent detecting circuit is used as the abnormality
detecting unit.
[0020] An overcurrent detecting circuit of a regulator having an
overcurrent protection function can be used for the abnormality
detecting unit.
[0021] As still another aspect of the present invention, a
configuration can be adopted in which the first regulator includes
the overcurrent detecting circuit, and includes a self-shutdown
circuit that stops output automatically in a case where overcurrent
is detected, and a self-shutdown circuit built in the first
regulator is used as the power supply stop unit.
[0022] A regulator having a self-shutdown function against an
overcurrent functions also as the abnormality detecting unit and
the power supply stop unit.
[0023] As a still further aspect of the present invention, a
configuration can be adopted in which the second regulator includes
the overcurrent detecting circuit, and includes a self-shutdown
circuit that stops output automatically in a case where overcurrent
is detected, and a self-shutdown circuit built in the second
regulator is used as the power supply stop unit.
[0024] If an abnormality occurs in a circuit mounted on the distal
end portion and an overcurrent flows, an electric current supplied
from the second regulator also increases. Accordingly, an
abnormality (overcurrent) of the distal end portion can be
indirectly detected by adopting a regulator with an overcurrent
protection function as the second regulator. Additionally, the
output of the first regulator is also stopped by stopping the
output of the second regulator.
[0025] As a still further aspect of the present invention, a
configuration can be adopted in which the second circuit part
includes a control circuit that controls the operation of the
second regulator, the second regulator includes the overcurrent
detecting circuit, a signal is sent to the control circuit if
overcurrent is detected by the overcurrent detecting circuit, and
the control circuit provides a control signal stopping the output
of the second regulator to the second regulator on the basis of the
signal, thereby cutting off the supply of power from the second
regulator.
[0026] Even in a case where the second regulator is not provided
with the self-shutdown circuit, the detection information of the
overcurrent detecting circuit can be notified to the control
circuit in the second circuit part, and the operation of the second
regulator can be stopped via the control circuit.
[0027] As a still further aspect of the present invention, a
configuration can be adopted in which the second circuit part is
arranged at a connector portion formed at the end portion of the
cable opposite to the first circuit part.
[0028] The second circuit part, which is electrically connected to
the first circuit part through the cable, can be arranged at a
place apart from the endoscope distal end portion. Although the
arrangement place of a second circuit part is arbitrary, for
example, an aspect is possible in which the second circuit part is
arranged at a connector portion that couples the electronic
endoscope apparatus and the light source device together, a
connector portion that couples the electronic endoscope apparatus
and the processor device together, the manipulating part of the
electronic endoscope, or the like.
[0029] As a still further aspect of the present invention, the
electronic endoscope apparatus preferably further includes a
feedback circuit that returns an input voltage, which is supplied
to the first regulator via the power supply line from the second
regulator, to the second regulator.
[0030] According to this aspect, the influence of a voltage drop by
the cable can be compensated for, and an input voltage to the first
regulator can be maintained at a desired value. This can suppress
wasteful heat generation in the case of voltage conversion by the
first regulator.
[0031] In the present invention, a CMOS (Complementary Metal Oxide
Semiconductor) type solid-state imaging element can be used for the
solid-state imaging element.
[0032] As compared to a CCD (Charge Coupled Device) sensor, the
CMOS type solid-state imaging element allows integration with a
drive circuit and its peripheral circuit, and allows a small sensor
module to be accommodated in the distal end portion.
[0033] For example, the imaging device is able to have a
configuration including an A/D converter that converts voltage
signals read from the solid-state imaging element into digital
signals and a parallel/serial converter that converts imaging
signals digitized by the A/D converter into serial signals from
parallel signals.
[0034] In addition, an aspect is preferable in which an LVDS (Low
Voltage Differential Signaling) transmission system that is not
easily influenced by disturbance noise is adopted as a signal
transmission system of imaging signals converted into serial
signals.
[0035] Additionally, in order to achieve the above object, there is
provided an electronic endoscope system including: an electronic
endoscope apparatus having an imaging device, having a solid-state
imaging element that images a region to be observed, built in a
distal end portion of an endoscope insertion part; a processor
device that performs signal processing on imaging signals output
from the imaging device of the electronic endoscope apparatus; and
a light source for illumination that generates illumination light
to be irradiated to a region to be observed from an illumination
window provided at a distal end face of the endoscope insertion
part. The electronic endoscope apparatus includes: a first
regulator arranged within the distal end portion along with the
imaging device, and supplying electric power of a required voltage
to the imaging device; a cable including signal lines that transmit
signals obtained from the imaging device and a power supply line
that supplies electric power to the first regulator; a second
circuit part electrically connected to a first circuit part
including the imaging device and the first regulator within the
distal end portion via the cable; a second regulator mounted on the
second circuit part and connected to the first regulator via the
power supply line; an abnormality detecting unit that detects at
least one abnormality of a temperature abnormality and an
overcurrent in the distal end portion; and a power supply stop unit
that stops the output from at least one regulator of the first
regulator and the second regulator in a case where an abnormality
is detected by the abnormality detecting unit.
[0036] Although a configuration is also possible in which the light
source for illumination is arranged at the distal end portion of
the endoscope insertion part, a configuration is adopted in which
illumination light is guided to the distal end of the endoscope
insertion part using an optical fiber or other light guides, in a
case where a light source is installed outside.
[0037] As an aspect of the electronic endoscope system of the
present invention, a configuration can be adopted in which the
second circuit part is arranged at a connector portion that
detachably couples together the electronic endoscope and the light
source for illumination.
[0038] According to the present invention, electric power of a
proper voltage can be supplied to the distal end portion of the
endoscope insertion part, and a distal end temperature can be
prevented from reaching a temperature higher than an allowable
temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a schematic configuration view showing the
schematic configuration of an electronic endoscope system related
to an embodiment of the invention.
[0040] FIG. 2 is a front view showing a distal end portion of an
insertion part in an electronic endoscope.
[0041] FIG. 3 is a lateral cross-sectional view showing the distal
end portion of the insertion part in the electronic endoscope.
[0042] FIG. 4 is a block diagram showing the configuration of the
electronic endoscope and a processor device in the endoscope system
of this example.
[0043] FIG. 5 is a block diagram of main parts showing the internal
configuration of the endoscope distal end portion and the
configuration of a scope board in a first embodiment.
[0044] FIG. 6 is a block diagram of main parts of a second
embodiment.
[0045] FIG. 7 is a block diagram of main parts of a third
embodiment.
[0046] FIG. 8 is a block diagram of main parts of a fourth
embodiment.
[0047] FIG. 9 is a block diagram of main parts of a fifth
embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] Embodiments of the present invention will be described below
in detail with reference to the accompanying drawings.
First Embodiment
[0049] FIG. 1 is a schematic configuration view showing the
schematic configuration of an electronic endoscope system related
to an embodiment of the present invention. As shown in FIG. 1, an
endoscope system 10 of the present embodiment is constituted by an
electronic endoscope 12, a processor device 14, a light source
device 16, or the like. The electronic endoscope 12 has a flexible
insertion part 20 to be inserted into a body cavity of a patient
(subject), a manipulating part 22 continuously provided at a
proximal end portion of the insertion part 20, a flexible portion
24 connected to the processor device 14 and the light source device
16.
[0050] A distal end portion 26 in which a CMOS imaging device
(imaging chip) 54 (refer to FIG. 3) for imaging the inside of a
body cavity, or the like is built is continuously provided at the
distal end of the insertion part 20. A curvable portion 28 in which
a plurality of curved pieces are coupled together is provided
behind the distal end portion 26. The curvable portion 28 is
operated to curve in vertical and horizontal directions as an angle
knob 30 provided at the manipulating part 22 is manipulated and a
wire provided so as to be inserted into the insertion part 20 is
pushed or pulled. This causes the distal end portion 26 to be
directed in a desired direction within a body cavity.
[0051] A proximal end of the flexible portion 24 is coupled to a
connector 36. The connector 36 is of a complex type, and not only
the light source device 16 but also the processor device 14 are
connected to the connector 36. Although not shown in FIG. 1, an
electronic circuit board (designated by reference numeral 130 in
FIG. 5) referred to as a scope board is arranged inside the
connector 36. The configuration of the scope board will be
described below.
[0052] The processor device 14 supplies electric power to the
electronic endoscope 12 via a cable 68 (refer to FIG. 3) inserted
into the flexible portion 24, controls driving of a CMOS imaging
device 54, receives imaging signals transmitted via the cable 68
from the CMOS imaging device 54, and performs various signal
processing on the received imaging signals to convert the signal
into image data. The image data converted by the processor device
14 is displayed as an endoscope image on a monitor 38 (equivalent
to a "display device") that is connected by cable to the processor
device 14. Additionally, the processor device 14 is electrically
connected to the light source device 16 via the connector 36, and
controls the operation of the endoscope system 10 in general.
[0053] FIG. 2 is a front view showing the distal end portion 26 of
the electronic endoscope 12. As shown in FIG. 2, a distal end face
26a of the distal end portion 26 is provided with an observation
window 40, illumination windows 42, a forceps outlet 44, and an air
and water supply nozzle 46. The observation window 40 is arranged
at the center of one side of the distal end portion 26. The
illumination windows 42 are arranged at two positions symmetrical
with respect to the observation window 40, and irradiate a region
to be observed within a body cavity from the light source device
16. The forceps outlet 44 is connected to a forceps channel 70
(refer to FIG. 3) disposed within the insertion part 20, and
communicates with a forceps port 34 (refer to FIG. 1) provided in
the manipulating part 22. Various treatment tools having an
injection needle, a diathermy knife, or the like disposed at the
distal end thereof are inserted through the forceps port 34, and
distal ends of the various treatment tools are exposed from the
forceps outlet 44. The air and water supply nozzle 46 jets washing
water or air, which is supplied from an air and water supply device
built in the light source device 16, toward the observation window
40 or a body cavity, according to the manipulation of the air and
water supply button 32 (refer to FIG. 1) provided at the
manipulating part 22.
[0054] FIG. 3 is a lateral cross-sectional view showing the distal
end portion 26 of the electronic endoscope 12. As shown in FIG. 3,
a lens barrel 52 holding an objective optical system 50 for taking
in image light of a region to be observed within a body cavity is
disposed at the back of the observation window 40. The lens barrel
52 is attached so that the optical axis of the objective optical
system 50 becomes parallel to the central axis of the insertion
part 20. A prism 56, which deflects the image light of the region
to be observed which has passed through the objective optical
system 50 approximately at a right angle and guides the image light
toward the CMOS imaging device 54, is connected to a rear end of
the lens barrel 52.
[0055] The CMOS imaging device 54 is a monolithic semiconductor
(so-called CMOS sensor chip) in which a CMOS type solid-state
imaging element (hereinafter referred to as a "CMOS sensor") 58,
and a peripheral circuit 60 that performs the driving of the CMOS
sensor 58 and the input/output of a signal are formed integrally,
and is mounted on a supporting substrate 62. An imaging surface 58a
of the CMOS sensor 58 is arranged so as to face the emitting
surface of the prism 56. A rectangular plate-shaped cover glass 64
is attached onto the imaging surface 58a via a rectangular
frame-shaped spacer 63. The CMOS imaging device 54, the spacer 63,
and the cover glass 64 are assembled together with adhesive. This
protects the imaging surface 58a from entry of dust or the
like.
[0056] A plurality of input/output terminals 62a are provided side
by side in the width direction of the supporting substrate 62 at a
rear end portion of the supporting substrate 62 that is provided to
extend toward the rear end of the insertion part 20. Signal lines
66 for intermediating exchange of various signals with the
processor device 14 via the flexible portion 24 are joined to the
input/output terminals 62a, and the input/output terminals 62a are
electrically connected to the peripheral circuit 60 in the CMOS
imaging device 54 via wiring lines, bonding pads (not shown), or
the like that are formed on the supporting substrate 62. The signal
lines 66 are packed and inserted into the flexible tubular cable
68. The cable 68 is inserted through the inside of each of the
insertion part 20, the manipulating part 22, and the flexible
portion 24, and is connected to the connector 36.
[0057] Additionally, although illustration is omitted in FIG. 2,
illumination parts are provided at the back of the illumination
windows 42. An emission end (reference numeral 106a in FIG. 4) of
the light guide (reference numeral 106 in FIG. 4), which guides the
illumination light from the light source device 16, is arranged at
the illumination part. The light guide 106, similarly to the cable
68, is inserted through the inside of each of the insertion part
20, the manipulating part 22, and the flexible portion 24, and an
incidence end is connected to the connector 36.
[0058] FIG. 4 is a block diagram showing the configuration of the
electronic endoscope 12 and the processor device 14 in the
endoscope system 10. As shown in FIG. 4, the CMOS imaging device
(imaging chip) 54 in which the CMOS sensor 58 and the peripheral
circuit 60 (refer to FIG. 3) are formed in the same chip is built
in the distal end portion 26 of the electronic endoscope 12
(insertion part 20), and the peripheral circuit 60 is equipped with
an analog signal processing circuit (AFE; analog front end) 72, a
parallel/serial (P/S) converter 76, an LVDS transmitter 78, a
register 80, a timing generator (TG) 81, or the like. Additionally,
the CMOS imaging device 54 includes a crystal oscillator 82 for
generating clock signals that are required for the driving of the
CMOS sensor 58.
[0059] The CMOS sensor 58 includes photodiodes that are formed for
respective pixels that are arranged in a matrix, a voltage
conversion circuit that coverts signal charges stored by the
photodiodes into voltage signals, scanning circuits (a
vertical-scanning circuit and a horizontal scanning circuit) that
specify the addresses (positions) of the pixels that read voltage
signals from the voltage conversion circuit, and an output circuit
that outputs the voltage signals of the pixels read by the scanning
circuits in order.
[0060] The AFE 72 is constituted by a correlated double sampling
(CDS) circuit, a gain setting circuit (PGA; Programmable Gain
Amplifier), and an analog/digital (A/D) converter. The CDS circuit
performs correlated double sampling processing on imaging signals
including pixel signals sequentially read from the respective
pixels of the CMOS sensor 58, and performs rejection of a reset
noise made and an amplifier noise arising in the CMOS sensor 58.
The PGA amplifies the imaging signals on which noise rejection has
been performed by the CDS circuit with a gain (amplification
factor) specified from the processor device 14. The A/D converter
converts and outputs the imaging signals (analog imaging signals)
amplified by the PGA, into digital signals with a predetermined
number of bits. The imaging signals (digital imaging signals) that
are digitized and output by the A/D converter are input to the P/S
converter 76.
[0061] The P/S converter 76 converts the imaging signals input from
the A/D converter of the AFE 72 into serial signals from parallel
signals. The serial signals generated by the P/S converter 76 are
input to the LVDS transmitter 78.
[0062] The LVDS transmitter 78 outputs the serial signals input
from the P/S converter 76 by an LVDS (Low Voltage Differential
Signal) transmission system capable of high-speed transmission as
differential signals. The differential signals output from the LVDS
transmitter 78 are input to the LVDS receiver 84 of the processor
device 14 through an LVDS line 96 including two signal lines.
[0063] The register 80 is a memory that stores various pieces of
control data that determine the processing contents of the
respective parts in the CMOS imaging device 54. The control data
stored in the register 80 includes various kinds of control
information for determining various operation modes (a still image
priority mode, a moving image priority mode, a frame rate, or the
like) of the CMOS imaging device 54, such as scan modes (full pixel
scanning/interlace scanning) of pixels, pixel regions to scan
(positions of pixels where scanning starts or ends), and shutter
speed (exposure time). The control data is input to the register 80
through a serial line 98 from the processor device 14. The control
data input from the processor device 14 is stored in the register
80, and the respective parts of the CMOS imaging device 54 perform
various kinds of processing according to register values (that is,
the control data input from the processor device 14) stored in the
register 80.
[0064] The TG 81 generates driving pulses for reading pixel signals
from the CMOS sensor 58, on the basis of the clock obtained from
the crystal oscillator 82, or synchronizing pulses of the
respective parts, such as the AFE 72, and supplies the driving
pluses to the respective parts of the CMOS imaging device 54. Then,
the respective parts of the CMOS imaging device 54 performs various
kinds of processing according to the pulses supplied from the TG
81. The CMOS sensor 58 can collect up the AFE 72 or the like and
can collect up the AFE or the like in the same package.
Additionally, the CMOS sensor 58 and the crystal oscillator 82 can
be housed in the same semiconductor package. This example provides
a sensor module in which the CMOS sensor 58 and the AFE 72 are
housed in the same semiconductor package. Additionally, the crystal
oscillator 82 is constituted as a package that is separate from the
package of the CMOS sensor 58, and the crystal oscillator 82 is
arranged near the CMOS sensor 58.
[0065] Additionally, in the endoscope system 10 of this example,
the temperature sensor 100 is arranged inside the distal end
portion 26 as a unit that detects the temperature of the distal end
portion 26 (refer to FIG. 1) of the insertion part 20 (refer to
FIG. 4). For example, a thermistor, a thermal diode, or the like
can be used for the temperature sensor 100. The thermistor is a
semiconductor element (resistance circuit element) in which
electric resistance changes greatly depending on differences in
temperature. The thermal diode is an element that measures
temperature using the temperature dependency of the voltage drop of
a pn-junction. Temperature is obtained from the relationship
between voltage and current in a forward direction by allowing a
fixed electric current to flow through this element. Such a
temperature sensor element can be housed in the same semiconductor
package as the CMOS sensor 58 along with the circuit of the AFE 72
or the like.
[0066] Otherwise, a temperature sensor IC (for example, CMOS
temperature sensor TC) of a package that is separate from the CMOS
sensor 58 can be adopted as the temperature sensor 100. As for the
temperature sensor IC, a temperature sensor, a constant current
circuit, and an operational amplifier or are integrated into a
chip.
[0067] Signals obtained from the temperature sensor 100 are
transmitted to a CPU 83 of the processor device 14 via the scope
board (not shown in FIG. 4, reference numeral 130 of FIG. 5).
However, a signal transmission unit for transmitting signals
(detection signals) from the temperature sensor 100 to the CPU 83
is not limited particularly. For example, an aspect is also
possible in which the detection signals of the temperature sensor
100 are sent to the AFE 72, the signal of the temperature sensor
100 along with the image signals are also A/D-converted by the AFE
72, and the image signals and the temperature sensor signal are
supplied to the processor device 14 via the LVDS line 96 in
combination.
[0068] The processor device 14 includes the CPU 83, the LVDS
receiver 84, a clock data recovery (CDR) circuit 86, a
serial/parallel (S/P) converter 88, an image-processing circuit
(DSP) 90, a display control circuit 92, or the like.
[0069] The CPU 83 functions as an unit that functions as a control
device that controls the respective parts in the processor device
14 and controls light emission and diaphragming (iris) of the light
source device 16.
[0070] The LVDS receiver 84 performs communication based on the
LVDS transmission system, and receives imaging signals (serial
signals) transmitted as differential signals from the LVDS
transmitter 78. The imaging signals transmitted through the LVDS
line 96 are serial signals in which clock signals and image data
are mixed. The imaging signals received by the LVDS receiver 84 are
input to the S/P converter 88 via the CDR circuit 86.
[0071] The CDR circuit 86 detects the phase of the imaging signals
serial-transmitted out from the CMOS imaging device 54, and
generates extraction clock signals synchronized with the frequency
of the imaging signals. By sampling imaging signals by the
extraction clock signals, data (returning data) obtained by
returning the imaging signals by the extraction clock signals is
generated.
[0072] Data required for various kinds of control by the CPU 83 is
stored in a data storage 94. The CPU 83 reads the data from the
data storage 94 if necessary, and uses the data for processing.
[0073] The S/P converter 88 converts the imaging signals (retiming
data) input via the CDR circuit 86 from the LVDS receiver 84 into
parallel signals from serial signals, and restores the imaging
signals to original imaging signals before the conversion in the
P/S converter 76 of the CMOS imaging device 54. The imaging signals
converted into the parallel signals by the S/P converter 88 are
input to the DSP 90.
[0074] The DSP 90 performs color interpolation, color separation,
color balance adjustment, gamma correction, image enhancement
processing, or the like, on the imaging signals input from the S/P
converter 88, and generates image data. The image data on which
various kinds of image processing are performed and generated in
the DSP 90 is input to the display control circuit 92.
[0075] The display control circuit 92 converts the image data input
from the DSP 90 into video signals according to signal formats
corresponding to the monitor 38 and outputs the image data to the
monitor 38.
[0076] When the inside of a body cavity is observed by the
endoscope system 10 configured as described above, the power
sources of the electronic endoscope 12, the processor device 14,
the light source device 16, and the monitor 38 are turned on, the
insertion part 20 of the electronic endoscope 12 is inserted into
the body cavity, and an image within the body cavity captured by
the CMOS imaging device 54 is observed with the monitor 38 while
the inside of the body cavity is illuminated with the illumination
light from the light source device 16.
[0077] In that case, control data for controlling the respective
parts of the CMOS imaging device 54 is generated in the CPU 83 of
the processor device 14. The generated control data is transmitted
to the electronic endoscope 12 through the serial line 98, and is
stored in the register 80 of the CMOS imaging device 54. The
respective parts of the CMOS imaging device 54 perform various
kinds of processing according to register values (control data)
stored in the register 80.
[0078] After the imaging signals generated by the CMOS sensor 58
are subjected to various kinds of processing by the AFE 72, the
imaging signals are converted into serial signals from parallel
signals by the P/S converter 76, and are transmitted to the
processor device 14 as differential signals according to the LVDS
transmission system from the LVDS transmitter 78.
[0079] In the processor device 14, the imaging signals received by
the LVDS receiver 84 are converted into original parallel signals
by the S/P converter 88. In the DSP 90, various kinds of signal
processing are performed on the input imaging signals, generating
image data. The image data generated by the DSP 90 is input to the
display control circuit 92. In the display control circuit 92,
conversion processing corresponding to the display format of the
monitor 38 is performed on the input image data, generating video
signals. The video signals generated by the display control circuit
92 are output to the monitor 38. This allows the image data to be
displayed as an endoscope image on the monitor 38.
[0080] Configuration of Scope Board
[0081] FIG. 5 is a block diagram of main parts showing the internal
configuration of the endoscope distal end portion and the
configuration of the scope board in the first embodiment.
[0082] In FIG. 5, elements that are the same or similar to the
configuration described in FIG. 4 are designated by the same
reference numerals. The scope board 130 is arranged inside the
connector described with reference numeral 36 of FIG. 1. A circuit
group that relays delivery of signals between the electronic
endoscope 12 and the processor device 14, and functions as a relay
board is mounted on the scope board 130. The scope board 130 is
equivalent to a "second circuit part".
[0083] A distal end circuit part 110 (equivalent to a "first
circuit part") arranged at the endoscope distal end portion
includes the CMOS imaging device 54 including the CMOS sensor 58
and its peripheral circuit, the temperature sensor 100, a first
regulator 114 as a power circuit, and an oscillator 116 that
generate clock signals. The first regulator 114 is a voltage
conversion device that generates a plurality of types of
predetermined voltages (for example, three types of direct current
voltages with different voltage values) supplied to the respective
circuit parts of the CMOS imaging device 54, and functions as a
supply source of power to the respective circuit parts within the
endoscope distal end portion 126.
[0084] The oscillator 116 is equivalent to the crystal oscillator
82 described in FIG. 4, and generates clock signals required for
the driving of the CMOS sensor 58.
[0085] The scope board 130 is mounted with a CPU 132, an LVDS
buffer 134, a second regulator 136, an A/D converter 138, and a
memory 140. The CPU 132 communicates with the CMOS imaging device
54 of the distal end portion 26 via the serial line 98.
Additionally, the CPU 132 communicates with the CPU 83 (refer to
FIG. 1) of the processor device 14, and controls the endoscope
system 10 in cooperation with the CPU 83
[0086] The image data output from the CMOS imaging device 54 is
sent to the LVDS buffer 134 via the LVDS line 96. Serial data sent
out from CMOS imaging device 54 is once buffered by the LVDS buffer
134, and then transferred to the processor device 14. Additionally,
although not shown, the scope board 130 detects various switches of
the manipulating part 22 described in FIG. 1, and includes a
circuit that performs communication of switch signals (manipulate
signals) with the processor device 14.
[0087] Specific information of the scope is stored in the memory
140. The electronic endoscope (scope) holds individual pieces of
data in the memory 140 for every model, and performs optimal
control for an instrument on the basis of this information. By
adopting such a configuration, it is possible to commonly use the
processor device 14 and the light source device 16 regarding
various variations of the scope.
[0088] The second regulator 136 as a power circuit for supplying
electric power to the first regulator 114 of the endoscope distal
end portion is provided within the scope board 130. Power of a
predetermined voltage is supplied to the first regulator 114 of the
endoscope distal end portion via a power supply line 146 from the
second regulator 136. The voltage of a power source input terminal
of the first regulator 114 is fed back to the second regulator 136
via a feedback circuit (return line) 148, and the output of the
second regulator 136 is controlled automatically. A predetermined
voltage (for example, 3 V) is supplied to the first regulator 114
of the endoscope distal end portion by such feedback control.
[0089] According to such a configuration, even in a case where the
model of the scope (electronic endoscope 12) is changed, electric
power of a proper voltage value is supplied to the first regulator
114 of the distal end portion by the voltage feedback control
function between the first regulator 114 and the second regulator
136 in the electronic endoscope of each model.
[0090] After signals obtained from the temperature sensor 100 are
converted into digital signals from analog signals by the A/D
converter 138, the signals are input to the CPU 132 of the scope
board 130.
[0091] If a temperature abnormality of the endoscope distal end
portion 26 is detected by the temperature sensor 100, the CPU 132
controls the second regulator 136 to stop the supply of electric
power from the second regulator 136. Specifically, the CPU 132 sets
an enable signal of the second regulator 136 to "OFF", bringing the
second regulator 136 into non-operation (output off), and stops the
supply of a power voltage to the first regulator 114 of the
endoscope distal end portion. As a result, the output of the first
regulator 114 is also stopped, and the supply of power to the CMOS
imaging device 54 is cut off.
[0092] According to such a configuration, if a temperature
abnormality of the distal end portion is detected, the supply of
electric power to the distal end portion is stopped, and a
temperature rise is suppressed, so that the distal end temperature
can be prevented from reaching a temperature higher than an
allowable temperature. Additionally, when the CPU 132 of the scope
board 130 performs the control of stopping the output of the second
regulator 136 with this abnormality detection, an aspect is
preferable in which the control of performing the communication
from the CPU 132 to the processor device 14 side to stop the light
emission of the light source device 16 or reduce the amount of
light emission.
Second Embodiment
[0093] FIG. 6 is a block diagram of main parts of a second
embodiment. In FIG. 6, elements that are the same or similar to the
example described in FIG. 5 are designated by the same reference
numerals, and the description thereof is omitted. In addition, in
order to simplify illustration in FIG. 6, the description of the
oscillator 116, the LVDS buffer 134, the A/D converter 138, the
memory 140, and the feedback circuit 148, which are described in
FIG. 5, is omitted. This is also the same in FIGS. 7 to 9.
[0094] The second embodiment of FIG. 6 is that a thermal diode (not
shown) is assembled into the CMOS imaging device 54, instead of the
temperature sensor 100 (thermistor) of FIG. 5. If abnormal heat
generation is detected within the imaging element module (CMOS
imaging device 54) in which a temperature detecting element is
assembled, the detection information is notified to the CPU 132
within the scope board 130. The CPU 132 controls the second
regulator 136 to stop the output of the second regulator 136, on
the basis of a temperature abnormality detection signal obtained
from the distal end circuit part 110. Specifically, the CPU 132
sets an enable signal of the second regulator 136 to "OFF",
bringing the second regulator 136 into non-operation (output off),
and stops the supply of a power voltage to the first regulator 114
of the endoscope distal end portion. As a result, the output of the
first regulator 114 is also stopped, and the supply of power to the
CMOS imaging device 54 is cut off. Moreover, the CPU 132 preferably
performs the control of performing notification to the CPU 83 of
the processor device 14, to stop the light emission of the light
source device 16 or reduce the amount of light emission.
Third Embodiment
[0095] FIG. 7 is a block diagram of main parts of a third
embodiment. In FIG. 7, elements that are the same or similar to the
example described in FIGS. 5 and 6 are designated by the same
reference numerals, and the description thereof is omitted.
[0096] The third embodiment shown in FIG. 7 has a configuration in
which elements for detecting temperature, such as the temperature
sensor 100 described in FIG. 5 or the thermal diode described in
FIG. 6, are not provided. While the configuration in which the
temperature detecting element is omitted is adopted, the first
regulator 150 to be mounted on the endoscope distal end portion
includes an overcurrent detecting circuit 152, and a shutdown
circuit 154 that performs a self-shutdown when overcurrent is
detected. An overcurrent protection circuit is constituted by the
combination of the overcurrent detecting circuit 152 and the
shutdown circuit 154. That is, an overcurrent protection circuit,
which monitors the amount of current that is output and which stops
output automatically when an output exceeding the amount of
allowable current is detected, is assembled into the first
regulator 150.
[0097] According to such a configuration, in a case where an
overcurrent occurs in the endoscope distal end portion due to some
causes, such as a circuit failure, supply of electric power is cut
off by the self-shutdown function of the first regulator 150. This
suppresses the temperature rise of the distal end portion.
Additionally, since supply of electric power is stopped quickly
after overcurrent detection, an abnormal state is not left for a
long time, and spreading of failure damage to an electronic circuit
can be prevented.
Fourth Embodiment
[0098] FIG. 8 is a block diagram of main parts of a fourth
embodiment. In FIG. 8, elements that are the same or similar to the
example described in FIGS. 5 and 6 are designated by the same
reference numerals, and the description thereof is omitted.
[0099] The fourth embodiment shown in FIG. 8 has a configuration in
which elements for detecting temperature, such as the temperature
sensor 100 described in FIG. 5 and the thermal diode described in
FIG. 6, are not provided. While the configuration in which the
temperature detecting element is omitted is adopted, the second
regulator 160 to be mounted on the scope board 130 includes an
overcurrent detecting circuit 162, and a shutdown circuit 164 that
perform a self-shutdown when overcurrent is detected. An
overcurrent protection circuit is constituted by the combination of
the overcurrent detecting unit 162 and the shutdown circuit 164.
That is, an overcurrent protection circuit, which monitors the
amount of current that is output and which stops output
automatically when an output exceeding the amount of allowable
current is detected, is assembled into the second regulator
160.
[0100] According to such a configuration, in a case where an
overcurrent occurs in the endoscope distal end portion due to some
causes, such as a circuit failure, since the amount of current that
the second regulator 160 of the scope board 130 outputs is also
increased, the overcurrent protection of the second regulator 160
works, and the supply of electric power to the endoscope distal end
portion is cut off by the self-shutdown function. As a result, the
output of the first regulator 114 is also stopped. This suppresses
the temperature rise of the distal end portion. Additionally, since
supply of electric power is stopped quickly after overcurrent
detection, an abnormal state is not left for a long time, and
spreading of failure damage to an electronic circuit can be
prevented.
Fifth Embodiment
[0101] FIG. 9 is a block diagram of main parts of a fifth
embodiment. In FIG. 9, elements that are the same or similar to the
example described in FIGS. 5 and 6 are designated by the same
reference numerals, and the description thereof is omitted.
[0102] The fifth embodiment shown in FIG. 9 has a configuration in
which elements for detecting temperature, such as the temperature
sensor 100 described in FIG. 5 and the thermal diode described in
FIG. 6, are not provided. While the configuration in which the
temperature detecting element is omitted is adopted, the second
regulator 170 to be mounted on the scope board 130 includes an
overcurrent detecting circuit 172, and a circuit that notifies
information to the CPU 132 when overcurrent is detected. That is,
the second regulator 170 has a function of monitoring the amount of
current that is output, and notifying information to the CPU 132
when an output exceeding the amount of allowable current is
detected.
[0103] According to such a configuration, in a case where an
overcurrent occurs in the endoscope distal end portion due to some
causes, such as a circuit failure, since the amount of current that
the second regulator 170 of the scope board 130 outputs is also
increased, overcurrent is detected and the message is notified to
the CPU 132, by the overcurrent detection function of the second
regulator 170. The CPU 132 receives this signal to control the
second regulator 170 to stop the output of the second regulator
170. Specifically, the CPU 132 sets an enable signal of the second
regulator 170 to "OFF", bringing the second regulator 170 into
non-operation (output off), and stops the supply of a power voltage
to the first regulator 114 of the endoscope distal end portion. As
a result, the output of the first regulator 114 is also stopped,
and the supply of power to the CMOS imaging device 54 is cut off.
This suppresses the temperature rise of the distal end portion.
Additionally, since supply of electric power is stopped quickly
after overcurrent detection, an abnormal state is not left for a
long time, and spreading of failure damage to an electronic circuit
can be prevented.
[0104] Appropriate Combination of Respective Embodiments of First
to Fifth Embodiments
[0105] The configurations of the respective embodiments described
in the first to fifth embodiments can be combined appropriately.
For example, as the first regulator 114 of FIGS. 5 and 6, it is
possible to use a regulator with an overcurrent protection function
(reference numeral 150). Additionally, even in the embodiment
described in FIGS. 7 and 8, it is possible to perform the control
of performing the communication from the CPU 132 to the processor
device 14 to stop the light emission of the light source device 16
or reduce the amount of light emission at the time of cutoff of
power supply when overcurrent is detected.
[0106] Light-Emitting Source of Light Source Device 16
[0107] As the light-emitting source of the light source device 16,
a laser light source may be adopted, lamp light sources, such as a
xenon tube, may be adopted, or a light emission diode (LED) may be
adopted. In the laser light source or the LED light source,
adjustment of the amount of light emission or control of pulse
light emission is relatively easy. On the other hand, in the xenon
light source or the like, adjustment of the amount of light
emission of the light source itself is difficult. Therefore, the
amount of illumination light may be adjusted using a aperture
mechanism or the like.
[0108] Modification 1
[0109] In the above-described embodiments, the configuration in
which illumination light is guided to the endoscope distal end
portion via the light guide (optical fiber or the like) from the
light source device 16 has been illustrated. Instead of this
aspect, a configuration is also possible in which a light emission
source, such as a light emission diode (LED), is arranged at the
endoscope distal end portion in combination with this
configuration. In this case, power of the LED built in the
endoscope distal end portion is supplied from the first regulator
114 (or 150), and an illumination light can also be turned off by
the stopping of output of the first regulator 114 (or 150).
[0110] Modification 2
[0111] Instead of the aspects in which temperature detecting
elements, such as the temperature sensor 100 described in the above
first embodiment and the thermal diode described in the second
embodiment, are used, it is also possible to detect the temperature
of the distal end portion 26, using the frequency temperature
characteristics of the crystal oscillator 82 arranged at the distal
end portion 26. In this case, the temperature sensor 100 can be
omitted.
[0112] Since the crystal oscillator 82 has the property that the
oscillation frequency thereof fluctuates depending on temperature,
temperature can be estimated from the frequency. Specifically, for
example, in the processor device 14, the oscillation frequency of
the crystal oscillator 82 of the endoscope insertion part is
confirmed, for example, by counting pixel clocks (clocks of pixel
units) of image signals on the basis of clock signals extracted by
the CDR circuit 86, or measuring frame periods from image signals
or the like. Also, the temperature of the distal end portion 26 can
be estimated from correlation data (look-up table or the like) that
defines the relationship between the temperature stored in advance
in the data storage 94, and the oscillation frequency.
[0113] Modification 3
[0114] In the above-described embodiments, the CMOS sensor 58 is
used as the solid-state imaging element. However, the scope of
application of the present invention is not limited to this. As
compared to the CCD sensor, the CMOS sensor can be driven at a low
voltage, and easily cope with demands for increase in the number of
pixels and high-speed reading. Additionally, manufacture of the
sensor module is easy. However, when the present invention is
carried out, a configuration is also possible in which other types
of imaging elements, such as the CCD type solid-state imaging
element (CCD sensor), is adopted as well as the CMOS sensor.
[0115] Modification 4
[0116] Although the example in which the scope board 130 is
arranged within the connector 36 (refer to FIG. 1) of the flexible
portion 24 has been described in the above-described embodiments,
the arrangement place of the scope board 130 is not limited to this
example. For example, a configuration is also possible in which the
scope board is arranged at a separate connector portion (connector
of a portion coupled with the processor device 14) connected to the
connector 36. Otherwise, a form in which the scope board is
arranged at the manipulating part 22 (refer to FIG. 1) of the
electronic endoscope 12 is also considered.
[0117] Although the endoscope system and its control method of the
present invention have been described in detail above, the present
invention is not limited to the embodiments described above, and it
is needless to say that various improvements and modifications may
be performed without departing from the scope of the present
invention. A number of modifications can be made by those having
ordinary knowledge in the field concerned with the technical idea
of the present invention.
* * * * *