JP2009201541A - Imaging system and endoscopic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely and certainly detect the connection state of a signal line which connects a solid-state imaging element and an external device. <P>SOLUTION: An electron endoscope 42 includes a CCD type solid-state imaging element 42, which periodically performs resetting operation for destroying signal charge after charge-voltage conversion, built therein and a processor 11 receives the output signal Vout from the solid-state imaging element 42 through the signal line 48d to form an image. The processor 11 is provided with a resetting part extraction circuit 77 which receives the output signal Vout from the signal line 48d and extracts the resetting part, which is caused by the resetting operation of the solid-state imaging element 42, from the output signal Vout. The CPU 70 of the processor 11 determines whether the connection state of a signal line 48 is abnormal on the basis of the presence of the resetting part extracted by the resetting part extraction circuit 77. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging system and an endoscope system in which a solid-state imaging device and an external device are electrically connected via a signal line.

  An endoscope system controls an operation of an endoscope provided with a solid-state image sensor that images a body cavity (inside a subject) and the solid-state image sensor, and generates an image by receiving an output signal of the solid-state image sensor. It is a kind of imaging system provided with the external device (processor device) which performs. The solid-state imaging device and the external device are electrically connected by a plurality of signal lines, and the power supply voltage and the driving signal are transmitted from the external device to the solid-state imaging device via the plurality of signal lines. An output signal is transmitted from the image sensor to an external device.

  Since the signal line is housed in an insertion portion with a small diameter that is inserted into the body cavity, a signal line having an extremely fine diameter is used. On the distal end side of this insertion portion, a bending portion is continuously provided between the distal end portion in which the solid-state imaging element is incorporated. The bending portion is a movable portion for changing the direction of the distal end portion (the imaging direction by the solid-state imaging device) according to the operation of the operation portion provided at the proximal end portion of the insertion portion. Since the signal line is also inserted into the inside of the bending portion, there is a problem that the bending portion receives a large load when the bending portion is bent with a large curvature and disconnection occurs (see, for example, Patent Document 1). ).

In Patent Document 1, a conductor (core wire) is provided along a signal line from one end (connecting portion with an external device) to the other end (tip portion) of an endoscope, and the conduction state of the conductor is externally set. A technique for detecting the presence or absence of disconnection without disassembling the endoscope has been proposed.
JP 2001-269309 A

  However, in the technique described in Patent Document 1, since the conductor is a dummy wiring to the last, even if a disconnection is detected based on the conductive state of the conductor, the signal line itself is not disconnected, and the operation of the imaging system It is possible that there is no problem. On the other hand, it is also conceivable that the conductor is not disconnected and the signal line is not detected even though the signal line is disconnected and there is a problem in operation. As described above, the technique described in Patent Document 1 has a problem that the disconnection of the signal line cannot be accurately detected.

  Furthermore, with the technique described in Patent Document 1, it is impossible to detect a short circuit between signal lines. For example, when a signal line for transmitting an output signal of a solid-state image sensor and a signal line for transmitting a power supply voltage are short-circuited, an excessive current flows between the signal lines, and abnormal heat generation of the solid-state image sensor Or destruction may occur.

  The present invention has been made in view of the above problems, and provides an imaging system and an endoscope system that can accurately and reliably detect a connection state of a signal line that connects a solid-state imaging device and an external device. For the purpose.

  In order to achieve the above object, the imaging system of the present invention is connected to a solid-state imaging device that periodically performs a reset operation for discarding signal charges after charge-voltage conversion, the solid-state imaging device by a signal line, and the signal In an imaging system including an external device that generates an image by receiving an output signal from the solid-state imaging device via a line, the output signal is received from the signal line, and the reset signal is generated from the output signal. A reset unit extracting unit for extracting a reset unit; and a connection state determining unit for determining whether or not the connection state of the signal line is abnormal based on the presence or absence of the reset unit extracted by the reset unit extracting unit; , Provided.

  The connection state determination unit preferably determines that the connection state of the signal line is abnormal when the reset unit is not extracted for a predetermined time by the reset unit extraction unit.

  The solid-state imaging device is supplied with power and driven from the external device, and the connection state determination unit stops the power supply and drive control when the connection state of the signal line is determined to be abnormal. It is preferable to make it.

  Moreover, it is preferable to provide an error notification unit that performs error notification when the connection state determination unit determines that the connection state of the signal line is abnormal.

  Moreover, it is preferable that the reset part extraction means and the connection state determination means are provided in the external device.

  In addition, the endoscope system of the present invention is connected to an endoscope incorporating a solid-state image sensor that periodically performs a reset operation for discarding signal charges after charge-voltage conversion, and the solid-state image sensor and a signal line, In an endoscope system including an external device that receives an output signal from the solid-state imaging device via the signal line and generates an image, the output signal is received from the signal line, and the reset is performed from the output signal. A reset unit extracting unit that extracts a reset unit caused by an operation, and a connection that determines whether or not the connection state of the signal line is abnormal based on the presence or absence of the reset unit extracted by the reset unit extracting unit And a state determining means.

  It is preferable that a light source device that emits illumination light from the endoscope is provided, and the connection state determination unit stops the operation of the light source device when the connection state of the signal line is determined to be abnormal.

  According to the imaging system of the present invention, since the connection state of the signal line is detected based on the presence or absence of the reset unit in the output signal output from the solid-state imaging device, the signal line connecting the solid-state imaging device and the external device is detected. The connection state can be detected accurately and reliably.

  Further, according to the endoscope system of the present invention, since the connection state of the signal line connecting the solid-state imaging device and the external device can be detected accurately and reliably, the user recognizes the occurrence of the abnormality. Thus, observation within the body cavity can be stopped immediately.

  In FIG. 1, an endoscope system 2 includes an electronic endoscope 10, a processor device 11, a light source device 12, and the like. The electronic endoscope 10 is connected to a flexible insertion portion 14 that is inserted into a body cavity, an operation portion 15 that is connected to a proximal end portion of the insertion portion 14, a processor device 11, and a light source device 12. And a universal cord 16.

  At the distal end of the insertion portion 14, a distal end portion 17 in which a solid-state imaging device 42 (see FIG. 3) for intra-body cavity photographing is incorporated is continuously provided. Behind the distal end portion 17 is provided a bending portion 18 connecting a plurality of bending pieces. The bending portion 18 is bent in the vertical and horizontal directions when the angle knob 19 provided in the operation portion 15 is operated and the wire inserted in the insertion portion 14 is pushed and pulled. Thereby, the front-end | tip part 17 is orient | assigned to the desired direction in a body cavity.

  The base end of the universal cord 16 is connected to the connector 20. The connector 20 is of a composite type, and the light source device 12 is connected to the connector 20 in addition to the processor device 11.

  The processor device 11 supplies power to the electronic endoscope 10 via a signal line 48 (see FIG. 3) inserted into the universal cord 16 to control the driving of the solid-state image sensor 42 and from the solid-state image sensor 42. The output signal is received through the signal line 48, and the received output signal is subjected to various signal processing to be converted into image data. The image data converted by the processor device 11 is displayed as an endoscopic image on a monitor 21 connected to the processor device 11 by a cable. The processor device 11 is electrically connected to the light source device 12 via the connector 20 and controls the operation of the endoscope system 2 in an integrated manner.

  In FIG. 2, an observation window 30, an illumination window 31, a forceps outlet 32, and an air / water supply nozzle 33 are provided on the front surface 17 a of the distal end portion 17. The observation window 30 is disposed at the center on one side of the tip portion 17. Two illumination windows 31 are arranged at symmetrical positions with respect to the observation window 30 and irradiate the observation site in the body cavity with illumination light from the light source device 12. The forceps outlet 32 is connected to a forceps channel 50 (see FIG. 3) disposed in the insertion portion 14 and communicates with a forceps port 22 (see FIG. 1) provided in the operation portion 15. Various treatment tools having an injection needle, a high-frequency knife or the like disposed at the tip are inserted into the forceps port 22, and the tips of the various treatment tools are exposed from the forceps outlet 32. The air supply / water supply nozzle 33 is cleaned supplied from the air supply / water supply device built in the light source device 12 in accordance with the operation of the air supply / water supply button 23 (see FIG. 1) provided in the operation unit 15. Water or air is jetted toward the observation window 30 or the body cavity.

  In FIG. 3, a lens barrel 41 that holds an objective optical system 40 for taking in image light of a site to be observed in the body cavity is disposed behind the observation window 30. The lens barrel 41 is attached so that the optical axis of the objective optical system 40 is parallel to the central axis of the insertion portion 14. Connected to the rear end of the lens barrel 41 is a prism 43 that guides the image light of the site to be observed via the objective optical system 40 toward the solid-state image sensor 42 by bending it at a substantially right angle.

  The solid-state imaging device 42 is a CCD (Charge Coupled Device) type image sensor made of a semiconductor chip, and an imaging surface 42a is provided on the surface thereof. The solid-state imaging device 42 is disposed such that the imaging surface 42 a faces the emission surface of the prism 43 and the imaging surface 42 a is parallel to the optical axis of the objective optical system 40. On the imaging surface 42a, a rectangular plate-like cover glass 45 is attached via a square frame-like spacer 44. The solid-state imaging device 42, the spacer 44, and the cover glass 45 are assembled through an adhesive. Thereby, the imaging surface 42a is protected from intrusion of dust or the like.

  The solid-state image sensor 42 is mounted on the circuit board 46. The circuit board 46 holds the solid-state image sensor 42 so as to cover the lower surface and side surfaces of the solid-state image sensor 42. In addition to the solid-state image sensor 42, wiring (not shown) for transmitting a drive signal to the solid-state image sensor 42 is mounted on the circuit board 46. A plurality of input / output terminals 47 are arranged in the width direction of the circuit board 46 at the rear end of the circuit board 46 extending toward the rear end of the insertion portion 14. A signal line 48 (consisting of signal lines 48a to 48d shown in FIG. 6) is joined to the input / output terminal 47 to mediate exchange of various signals with the processor device 11 via the universal cord 16. The output terminal 47 is electrically connected to the solid-state image sensor 42 via the circuit board 46. The signal lines 48 are collectively inserted into a flexible tubular cable 49. The cable 49 is inserted into each of the insertion portion 14, the operation portion 15, and the universal cord 16 and is connected to the connector 20.

  In addition, an illumination lens 82 (see FIG. 6) is provided in the back of the illumination window 31. The illumination lens 82 faces the emission end of a light guide 81 (see FIG. 6) that guides illumination light from the light source device 12. Similarly to the cable 49, the light guide 81 is inserted through each of the insertion portion 14, the operation portion 15, and the universal cord 16, and the incident end is connected to the connector 20. The light guided from the light source device 12 to the illumination lens 82 by the light guide 81 is irradiated into the body cavity through the illumination window 31.

  In FIG. 4, a solid-state image sensor 42 is an interline transfer type CCD image sensor. The solid-state imaging device 42 is arranged in a two-dimensional matrix, and is provided for each of a plurality of light receiving elements (photodiodes) 60 that generate and store signal charges corresponding to incident light by photoelectric conversion, and for each vertical column of the light receiving elements 60. The plurality of vertical CCDs 61 that read the signal charges from the light receiving element 60 and transfer the read signal charges in the vertical direction, and the signal charges output from the vertical CCDs 61 are connected in common to the output terminals of the vertical CCDs 61 in the horizontal direction. The horizontal CCD 62 is connected to the output terminal of the horizontal CCD 62, and an output unit 63 that converts the signal charge output from the horizontal CCD 62 into a voltage and outputs the voltage to the outside. The vertical CCD 61 is a four-phase CCD and is driven by four types of vertical CCD drive pulses φV1 to φV4 having different phases. The horizontal CCD 62 is a two-phase CCD and is driven by two types of horizontal CCD drive pulses φH1 and φH2 having different phases.

  The output unit 63 includes an output gate 64, a floating diffusion (FD) unit 65, a reset gate 66, a reset drain 67, and a source follower having an input terminal connected to the FD unit 65. And a circuit 68. A predetermined gate voltage VOG is applied to the output gate 64, and the signal charge output from the output terminal of the horizontal CCD 62 according to the horizontal CCD drive pulses φH 1 and φH 2 is passed to the FD unit 65.

  The FD unit 65 accumulates the signal charge transferred from the horizontal CCD 62 via the output gate 64 and generates a voltage corresponding to the amount of accumulated signal charge. The source follower circuit 68 detects a voltage generated by the charge-voltage conversion in the FD unit 65, buffers the amplified voltage (impedance conversion), and outputs the detected voltage. A reset pulse φRG is applied to the reset gate 66 from the outside, and the signal charge after voltage-voltage conversion accumulated in the FD unit 65 is transferred before the signal charge of the next pixel is transferred from the horizontal CCD 62 to the FD unit 65. Are discarded to the reset drain 67 to which a predetermined reset drain voltage VRD is applied.

  As shown in FIG. 5, the output signal Vout output from the source follower circuit 68 includes, for each pixel period, a reset unit V1 corresponding to a period in which the reset pulse φRG is applied to the output gate 64, and the reset pulse φRG. It is divided into a field through portion V2 corresponding to a period in which the FD portion 65 is reset by application and a pixel signal portion V3 corresponding to a period in which signal charges are accumulated in the FD portion 65. The voltage of the reset unit V1 is caused by the reset operation by the reset gate 66 and is determined by the voltage of the reset pulse φRG and the coupling capacitance between the reset gate 66 and the FD unit 65.

  Although not shown, the solid-state image sensor 42 is a solid-state image sensor of a single plate color imaging system provided with a color filter composed of a plurality of color segments (for example, a primary color filter with a Bayer array).

  In FIG. 6, a processor device 11 includes a CPU 70, a power supply circuit 71, a timing generator (TG) 72, a CCD driver 73, a correlated double sampling (CDS) circuit 74, an analog / digital (A / D) converter 75, image processing. The circuit 76 and the reset part extraction circuit (reset part extraction means) 77 are comprised. The processor device 11 is electrically connected to the solid-state imaging device 42 in the electronic endoscope 10 via signal lines 48a to 48d.

  The CPU 70 controls each part in the processor device 11 and controls the entire endoscope system 2 in an integrated manner. The power supply circuit 71 generates a power supply voltage VDD and a ground voltage VSS, supplies the generated power supply voltage VDD and ground voltage VSS to each part in the processor device 11, and also uses the solid-state imaging device 42 via the signal lines 48 a and 48 b. To supply.

  The TG 72 generates a clock signal and supplies it to the CCD driver 73. Further, the TG 72 generates a clamp pulse and a sample hold pulse for correlated double sampling and supplies them to the CDS circuit 74, and also generates a clock signal for A / D conversion and supplies it to the A / D converter 75. .

  Based on the clock signal input from the TG 72, the CCD driver 73 generates drive signals such as the vertical CCD drive pulses φV1 to φV4, the horizontal CCD drive pulses φH1 and φH2, the reset pulse φRG, and the like, and sends a plurality of signal lines 48c. To the solid-state imaging device 42 in the electronic endoscope 10. The solid-state image sensor 42 performs an imaging operation according to the input drive signal. Since the CCD driver 73 always inputs the reset pulse φRG to the solid-state image sensor 42 at a constant cycle, the output signal Vout of the solid-state image sensor 42 is irrespective of the presence or absence of the pixel signal portion V3 (that is, in the dark or In the blanking period), the reset unit V1 always appears at a constant cycle.

  The output signal Vout output from the solid-state image sensor 42 is input to the CDS circuit 74. The CDS circuit 74 is a noise removal circuit, clamps the voltage of the field through portion V2 of the output signal Vout based on the clamp pulse supplied from the TG 72, and outputs the output signal Vout based on the sample hold pulse supplied from the TG 72. Is sampled and held, and a difference value (voltage difference) between the field through portion V2 and the pixel signal portion V3 is output as a signal.

  The A / D converter 75 quantizes the signal output from the CDS circuit 74 based on the A / D conversion clock signal supplied from the TG 72, for example, into a digital signal of 8 bits (256 gradations). The converted digital signal is input to the image processing circuit 76.

  The image processing circuit 76 performs image processing such as white balance adjustment, gain correction, color interpolation, edge enhancement, gamma correction, and color matrix calculation on the input digital signal to generate image data. The image processing circuit 76 converts the image data into a signal format for displaying on the monitor 21 and displays the image on the monitor 21.

  The reset part extraction circuit 77 extracts the reset part V1 included in the output signal Vout output from the solid-state image sensor 42. Specifically, as shown in FIG. 7, the reset unit extraction circuit 77 is configured by a comparator 90 composed of an operational amplifier. A capacitor 92 is connected to the “+” side input terminal of the comparator 90 via a buffer 91, and a reference voltage Vref is applied to the “−” side input terminal of the comparator 90. The output signal Vout is input to the “+” side input terminal of the comparator 90 through the capacitor 92 and the buffer 91 that remove the DC bias component.

  The comparator 90 compares the input output signal Vout with the reference voltage Vref, and as shown in FIG. 8, the portion below the reference voltage Vref is the ground voltage VSS and the portion above the reference voltage Vref is a positive voltage greater than the ground voltage VSS. Output as voltage. The reference voltage Vref is set to a value higher than the voltage of the field through portion V2 and lower than the voltage of the reset portion V1. As a result, a pulse wave-shaped extraction signal Vrs including only the reset unit V <b> 1 is output from the output terminal of the comparator 90, and the output extraction signal Vrs is sequentially input to the CPU 70.

  The CPU 70 functions as a connection state determination unit that monitors the extraction signal Vrs input from the reset unit extraction circuit 77 and determines the connection state of the signal line 48 that connects the solid-state imaging device 42 and the processor device 11. As described above, since the reset unit V1 always appears in the output signal Vout of the solid-state imaging device 42 at a constant cycle, the connection state of the signal line 48 can be determined by detecting the presence or absence of the reset unit V1. .

  Specifically, the CPU 70 activates the TG 72, starts a connection state detection operation, and detects a rising edge of the extraction signal Vrs input from the reset unit extraction circuit 77, thereby causing a period in the extraction signal Vrs. Whether or not the reset unit V1 exists is continuously determined. As shown in FIG. 9, when the CPU 70 detects that the reset unit V1 does not appear in the extraction signal Vrs for a predetermined time (at least one cycle of the reset pulse φRG), there is an abnormality in the connection state of the signal line 48. It determines with having occurred, and the stop process which stops operation | movement of each part is performed.

  In this stop process, the CPU 70 stops the imaging operation of the solid-state imaging device 42 by stopping the operation of the TG 72, then stops the operation of the power supply circuit 71, and further stops the light irradiation operation by the light source device 12. . In addition to the stop processing, the CPU 70 displays a message notifying the user that there is an abnormality in the connection state between the solid-state imaging device 42 and the processor device 11 on the monitor 21 via the image processing circuit 76, thereby allowing the user to An error notification is given to the user.

  The light source device 12 includes a light source 78 such as a xenon lamp or a halogen lamp, a light source driver 79 for driving the light source 78, and a condensing lens 80 that condenses light emitted from the light source 78. The light emitted from the light source 78 is condensed by the condenser lens 80, guided to the incident end of the light guide 81, and irradiated from the distal end portion 17 of the electronic endoscope 10 into the body cavity as described above. The light source driver 79 turns on / off the light emission operation of the light source 78 based on the control from the CPU 70.

  When observing the inside of a body cavity with the endoscope system 2 configured as described above, the electronic endoscope 10, the processor device 11, the light source device 12, and the monitor 21 are turned on, and the electronic endoscope is turned on. The insertion unit 14 is inserted into the body cavity, and an image in the body cavity imaged by the solid-state imaging device 42 is observed on the monitor 21 while illuminating the body cavity with illumination light from the light source device 12.

  At this time, processing according to the flowchart shown in FIG. 10 is performed. First, the CPU 70 operates the TG 72 and drives the solid-state imaging device 42 by the CCD driver 73. The output signal Vout from the solid-state imaging device 42 is transmitted into the processor device 11 through the signal line 48d and input to the reset unit extraction circuit 77 in addition to the CDS circuit 74. The reset part extraction circuit 77 extracts the reset part V1 included in the output signal Vout and sequentially inputs it to the CPU 70 as the extraction signal Vrs. The CPU 70 detects the presence or absence of the reset unit V1 in the extraction signal Vrs. When the reset unit V1 does not appear for a predetermined time (that is, when the reset unit V1 is not extracted by the reset unit extraction circuit 77), the signal is It is determined that the connection state of the line 48 is abnormal, and each part is controlled to stop the driving of the solid-state imaging device 42 and to stop the light irradiation operation by the light source device 12. At the same time as the stop process, the CPU 70 displays a message on the monitor 21 to notify an error. Thereby, the user of the endoscope system 2 can recognize the occurrence of the abnormality and immediately stop observation in the body cavity.

  As described above, the endoscope system 2 is based on the presence or absence of the reset unit V1 in the output signal Vout transmitted from the solid-state image sensor 42 to the processor device 11, and between the solid-state image sensor 42 and the processor device 11. Since the connection state is detected, any abnormality caused by any of the signal lines 48a to 48d can be detected as long as it causes the reset unit V1 to disappear. For example, the disconnection or short circuit of the other signal lines 48a to 48c is detected in addition to the disconnection of the signal line 48d or the short circuit with the other signal lines 48a to 48c (for example, the signal line 48b to which the ground voltage VSS is supplied). Can do. In this way, the endoscope system 2 can accurately detect the connection state of the signal line 48 without attaching a connection state detection conductor or the like along the signal line 48 as in the prior art.

  In addition, the light source device 12 is usually provided with a diaphragm mechanism (not shown) that controls the amount of illumination light based on the amount of light received by the solid-state image sensor 42, and the signal line 48 becomes in an abnormal state, causing solid-state imaging. When the output signal from the element 42 is interrupted, it is determined that the amount of received light has decreased, and the diaphragm mechanism operates to maximize the amount of illumination light. By performing the stop process, unnecessary light irradiation into the body cavity can be prevented.

  In the above-described embodiment, the reset unit extraction circuit 77 is configured by the comparator 90 including an operational amplifier. However, the present invention is not limited to this, and the reset unit extraction circuit 77 generates the reset unit V1 from the output signal Vout. As long as it can be extracted, a detection circuit such as a peak hold circuit or a sample hold circuit may be used. In this case, the CPU 70 may determine whether or not the detection unit is the reset unit V1 by determining whether or not the voltage value of the portion detected by the detection circuit is within a predetermined range.

  In the above embodiment, the CPU 70 detects the presence or absence of the reset unit V1 by detecting the rising edge of the extraction signal Vrs. However, the present invention is not limited to this, and the rising edge and the rising edge of the extraction signal Vrs are detected. It is also preferable to detect the falling edge and include the width (pulse width) from the rising edge to the falling edge in the detection condition of the reset unit V1. That is, by preventing erroneous detection of the pulse-like waveform caused by the abnormality of the signal line 48 as the reset unit V1, the detection accuracy of the reset unit V1 is improved, and as a result, the connection state of the signal line 48 is detected. The accuracy is further improved.

  In the above-described embodiment, the CPU 70 determines the connection state of the signal line 48 on the condition that the reset unit extraction circuit 77 does not continuously extract the reset unit V1 for a predetermined time. However, the present invention is not limited to this, and it is also preferable to add to the determination condition that the reset unit V1 is extracted at a cycle different from the original cycle (that is, a change in the appearance frequency of the reset unit V1). Thereby, it is also possible to detect that an intermittent failure (contact failure or the like) has occurred in the signal line 48 so as not to reach the disconnection or short circuit.

  In the above embodiment, the CPU 70 performs error notification on the condition that the reset unit V1 is not continuously extracted for a predetermined time by the reset unit extraction circuit 77. However, the present invention is not limited to this, and As shown in FIG. 11, it is also preferable to give a prior warning before the predetermined time elapses. This prior warning is to notify that there is a possibility of disconnection or a short circuit, and is performed by displaying a message on the monitor 21 as in the above error notification. With this advance warning, the user can take a quicker action such as stopping the observation before disconnection or short circuit occurs. The prior warning and error notification are not limited to message display on the monitor 21 and may be performed by other notification methods such as voice output.

  In the above-described embodiment, the reset unit extraction circuit 77 and the CDS circuit 74 to which the output signal Vout is input are provided in the processor device 11. However, the present invention is not limited to this, and the reset unit extraction circuit 77 and the CDS are provided. The circuit 74 may be provided inside the electronic endoscope 10 such as the operation unit 15.

  In the above embodiment, the endoscope system is described as an example of the imaging system. However, the present invention is not limited to this, and the solid-state imaging device and an external device are connected via a signal line. If the output signal of the solid-state image sensor is transmitted via a digital endoscope, an ultrasonic endoscope system that combines an electronic endoscope and an ultrasonic probe, or a digital camera in which a lens barrel having an imaging function can be attached to and detached from the main body The present invention can be applied to any imaging system such as a Web camera system including a camera and a personal computer.

It is a figure which shows schematic structure of an endoscope system. It is a figure which shows the front surface of the front-end | tip part of an electronic endoscope. It is an expanded partial sectional view which shows the structure of the front-end | tip part of an electronic endoscope. It is a circuit diagram which shows the structure of a solid-state image sensor. It is a timing chart explaining the waveform of the output signal from a solid-state image sensor. It is a block diagram which shows the structure of an endoscope system. It is a circuit diagram which shows the structure of a reset part extraction circuit. It is a timing chart explaining operation | movement of a reset part extraction circuit. It is a timing chart explaining the extraction signal of a reset part, and operation | movement of CPU. It is a flowchart explaining the effect | action of an endoscope system. It is a timing chart explaining the modification of operation | movement of CPU.

Explanation of symbols

2 Endoscope system 10 Electronic endoscope 11 Processor device (external device)
12 Light source device 21 Monitor (error notification means)
42 Solid-state image sensor 48 Signal line 48a-48d Signal line 65 FD part 66 Reset gate 67 Reset drain 70 CPU (connection state determination means)
71 Power supply circuit 73 CCD driver 77 Reset part extraction circuit (reset part extraction means)
78 Light source 79 Light source driver 90 Comparator

Claims (7)

A solid-state imaging device that periodically performs a reset operation for discarding signal charges after charge-voltage conversion, and is connected to the solid-state imaging device by a signal line, and receives an output signal from the solid-state imaging device via the signal line In an imaging system comprising an external device that generates an image,
A reset unit extracting means for receiving the output signal from the signal line and extracting a reset unit resulting from the reset operation from the output signal;
A connection state determination unit that determines whether or not the connection state of the signal line is abnormal based on the presence or absence of the reset unit extracted by the reset unit extraction unit;
An imaging system comprising:   The imaging system according to claim 1, wherein the connection state determination unit determines that the connection state of the signal line is abnormal when the reset unit is not extracted for a predetermined time by the reset unit extraction unit. The solid-state imaging device is supplied with power and driven from the external device,
The imaging system according to claim 1, wherein the connection state determination unit stops the power supply and drive control when the connection state of the signal line is determined to be abnormal.   The imaging system according to any one of claims 1 to 3, further comprising an error notification unit that performs error notification when the connection state determination unit determines that the connection state of the signal line is abnormal.   5. The imaging system according to claim 1, wherein the reset unit extraction unit and the connection state determination unit are provided in the external device. 6. An endoscope having a built-in solid-state imaging device that periodically performs a reset operation for discarding signal charges after charge-voltage conversion, and connected to the solid-state imaging device by a signal line, and from the solid-state imaging device via the signal line In an endoscope system comprising an external device that receives an output signal and generates an image,
A reset unit extracting means for receiving the output signal from the signal line and extracting a reset unit resulting from the reset operation from the output signal;
A connection state determination unit that determines whether or not the connection state of the signal line is abnormal based on the presence or absence of the reset unit extracted by the reset unit extraction unit;
An endoscope system comprising:   A light source device that emits illumination light from the endoscope is provided, and the connection state determination unit stops the operation of the light source device when the connection state of the signal line is determined to be abnormal. Item 7. The endoscope system according to Item 6.

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