JP2012020080A - Endoscopic device and method for driving solid-state image sensing device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the transfer efficiency of a small signal charge quantity obtained by photographing under specific light observation.SOLUTION: The endoscopic device includes a solid-state image sensing device having a plurality of pixels aligned and formed in a two-dimensional array shape on a semiconductor substrate and a plurality of vertical charge transfer paths formed respectively along a plurality of pixel lines constituted by the pixels, the image sensing device being built in a tip portion of an endoscope; and an endoscopic control unit which forms, in the vertical charge transfer paths, a signal packet 91 storing signal charges detected by the pixels in the vertical charge transfer paths, and transfers it, and further forms, in photographing under a specific light environment, an empty packet 90 which picks up transfer residual charges produced by the transfer of the signal packet 91 in the subsequent stage in the transfer direction of the signal packet 91.

Description

  The present invention relates to an endoscope apparatus, and more particularly to an endoscope apparatus equipped with a CCD solid-state image sensor and a method for driving the solid-state image sensor.

  A solid-state imaging device is mounted on the distal end portion of the endoscope that is inserted into the human body or the like, and an image of the observation site imaged by the solid-state imaging device is displayed on the external monitor device. As a solid-state imaging device, a CCD type that can capture an image with a high S / N ratio compared to a CMOS type is often used.

  Since the human body is in a dark place, the subject illumination light is configured to introduce light from an external light source into the endoscope through an optical fiber or the like and irradiate the observation site from the distal end portion of the endoscope. . As the subject illumination light, light generated by mixing light emitted from a xenon lamp or laser light of each color of R (red), G (green), and B (blue) is used.

  However, in recent years, in addition to the subject illumination light described above, for example, as described in Patent Documents 1 and 2 below, fluorescence or the like self-emitted by irradiating an observation site such as an affected part with excitation light It can be observed in the special light environment.

JP 2007-50106 A JP 2006-296635 A

  When imaging an observation site using special light, the amount of light is about three orders of magnitude less than white light such as a xenon lamp. For this reason, when observing with special light, the signal charge amount (number of electrons) detected by each pixel of the solid-state imaging device in accordance with the amount of incident light from the subject is an extremely small value.

  In the CCD type solid-state imaging device, the signal charge detected by each pixel is transferred and output using a vertical charge transfer path (VCCD). However, it is physical to make transfer efficiency at each transfer stage 100%. In other words, signal charges remain untransferred (transfer leakage).

  This signal charge transfer leakage is not a problem as long as the original signal charge amount is large as in the case of using white light as illumination light. However, when the original signal charge amount is very small as in fluorescence observation, even a slight leakage of signal charge significantly deteriorates the image quality of the observation site.

  An object of the present invention is to provide an endoscope apparatus that employs a driving method that reduces transfer leakage when imaging using a CCD solid-state imaging device in a special light environment with a small amount of light, and a solid-state imaging device driving method thereof. There is.

  The endoscope apparatus according to the present invention includes a plurality of pixels arrayed in a two-dimensional array on a semiconductor substrate and a plurality of vertical charge transfer paths formed along a plurality of pixel columns composed of the pixels. A solid-state imaging device built in the distal end portion of the endoscope and a signal packet containing the signal charge detected by the pixel are formed and transferred to the vertical charge transfer path, and the signal packet is used for shooting in a special light environment. And an endoscope control unit for forming and transferring an empty packet for picking up the remaining transfer charge generated by the transfer of the signal packet.

  In addition, the solid-state imaging device driving method of the endoscope apparatus according to the present invention is formed along a plurality of pixels arranged in a two-dimensional array on a semiconductor substrate and a plurality of pixel columns composed of the pixels. A method of driving a solid-state imaging device having a plurality of vertical charge transfer paths and built in the distal end portion of an endoscope, wherein a signal packet storing a signal charge detected by the pixel is formed and transferred to the vertical charge transfer path In addition, when photographing in a special light environment, an empty packet for picking up a transfer residual charge generated by the transfer of the signal packet is formed and transferred at a stage subsequent to the transfer direction of the signal packet.

  According to the present invention, by transferring an empty packet, even if a transfer leakage charge is generated from the preceding signal packet, it can be picked up by the empty packet, the transfer efficiency can be improved, and an observation part with high image quality can be achieved. Images can be obtained.

1 is an overall configuration diagram of an endoscope apparatus according to an embodiment of the present invention. It is a schematic functional block diagram of the endoscope apparatus shown in FIG. It is a principal part fracture | rupture figure of the scope part front-end | tip part of the endoscope apparatus shown in FIG. It is a detailed functional block diagram of the endoscope apparatus shown in FIG. It is a surface schematic diagram of the solid-state image sensor shown in FIG. It is a figure which shows the relationship between the photodiode of a solid-state image sensor shown in FIG. 5, and a transfer electrode. It is a flowchart which shows the process sequence of the transfer drive of the solid-state image sensor shown in FIG. It is explanatory drawing of the normal transfer mode shown in FIG. It is explanatory drawing of the empty packet transfer mode shown in FIG. FIG. 6 is an illustration of various embodiments of an empty packet transfer mode. It is a flowchart which shows the process procedure of the capacity | capacitance determination (a) and number determination (b) of an empty packet. It is a surface schematic diagram of another embodiment of the solid-state image sensor shown in FIG. It is a figure which shows the mode of the empty packet transfer of the solid-state image sensor of FIG. It is a figure which shows the mode of the empty packet transfer of another embodiment of the solid-state image sensor of FIG. It is a figure which shows the mode of the empty packet transfer of another embodiment of the solid-state image sensor of FIG. It is the surface schematic diagram of another embodiment (FT-CCD) of the solid-state image sensor shown in FIG. FIG. 17 is a schematic cross-sectional view (a) in the vertical direction of the solid-state imaging device shown in FIG. 16 and a state diagram (b) of a potential well. It is a figure which shows the normal transfer mode of the solid-state image sensor shown in FIG. It is a figure which shows the mode of the empty packet formation of the solid-state image sensor shown in FIG. It is a figure which shows the empty packet transfer mode of the solid-state image sensor shown in FIG. It is a functional block diagram of the endoscope apparatus of another embodiment which replaces FIG. 4 of this invention. It is a surface schematic diagram of the solid-state image sensor concerning another embodiment of the present invention. It is a figure which shows an example of the color filter arrangement | sequence of the solid-state image sensor which concerns on another embodiment of this invention. It is a surface schematic diagram of the solid-state image sensing device concerning another embodiment of the present invention. It is a surface schematic diagram of the solid-state image sensing device concerning another embodiment of the present invention. FIG. 5 is a functional block diagram of an endoscope apparatus according to still another embodiment instead of FIG. 4 of the present invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall external view of the endoscope apparatus. The endoscope apparatus 10 includes an endoscope 20 and a peripheral device 50. The endoscope 10 includes a hand operation unit 21, a flexible scope unit 22 connected to the distal end side of the hand operation unit 21 and inserted into the body cavity of the patient, and a peripheral operation unit 21 connected to the hand operation unit 21. Mounting portions 23 a and 23 b connected to the device 50 are provided.

  The peripheral device 50 includes a processor 51, a light source device 52, a monitor device 53, and an input device 54. The mounting portion 23a is detachably mounted on the processor 51, and the mounting portion 24b is detachably mounted on the light source device 52. Installed.

  FIG. 2 is a functional block diagram of the endoscope apparatus 10 shown in FIG. The mounting portion 23 b of the endoscope 20 is mounted on the light source device 52, and the illumination light emitted from the light source device 52 passes through two optical fiber bundles (light guides) 24 inserted into the endoscope 20. The observation site is irradiated from the endoscope distal end portion 25. In FIG. 2, an example in which illumination light is irradiated through two optical fiber bundles (light guides) is described. However, in the following description and other drawings, the illumination light is not limited to two irradiations. It may be a system or three or more systems.

  The light image of the subject light reflected at the observation site or the subject light self-emitted is converted into an electrical signal (captured image signal) by the CCD-type image sensor 26 built in the endoscope distal end portion 25, and the endoscope 20. The signal is inserted into the processor 51 by the signal wiring 27 inserted therein.

  The processor 51 captures a captured image signal of the observation site via the signal wiring 27, performs known image processing such as offset processing, γ conversion processing, RGB / YC conversion processing, and synchronization processing, and obtains the obtained subject image. Displayed on the monitor device 53.

  FIG. 3 is a fragmentary cutaway view of the endoscope distal end portion 25. A forceps hole 31 is opened at the distal end surface 30 of the endoscope distal end portion 25, and two concave lenses for diffusing and irradiating illumination light guided through the optical fiber bundle 24 of FIG. 32 and 33 are provided. In addition, a condensing lens 34 is provided at an intermediate portion between the two concave lenses 32 and 33, and the light reflected from the observation site or the self-emitted subject light is collected by the condensing lens 34. A nozzle 35 is also provided on the distal end surface 30, and a cleaning liquid for cleaning the photographing lens 34 can be ejected from the nozzle 35.

  The solid-state imaging device 26 built in the endoscope distal end portion 25 has a light receiving surface arranged perpendicular to the distal end surface 30, so that subject light is reflected on the back of the condensing lens 34 of the cylindrical distal end portion 25. A prism 36 is provided that bends the optical path at a right angle and causes the solid-state imaging device 26 to receive light.

  The solid-state imaging device 26 is fixedly installed on the wiring board 29, and the signal wiring 27 is drawn from the wiring board 29 and connected to the processor 51.

  FIG. 4 is a more detailed functional block diagram of FIG. In the light source device 52, the white light source 55, the excitation light source 56, the multiplexer 57 provided at the output of each light source 55, 56 and the output of the multiplexer 57 are divided into two systems, and two systems of lights The guide 24 includes a duplexer 58 that outputs via the mounting portion 23b.

  The multiplexer 57 does not multiplex the light emitted from the two light sources 55 and 56 but outputs the light emitted from one of the light sources to the demultiplexer 58 to demultiplex it into two systems. Provided. For this reason, a light source control unit 59 is provided in the light source device 52, and either one of the light sources is selected according to an instruction from the control unit 61 of the processor 51 to emit illumination light.

  The processor 51 includes a control unit 61, a memory (storage unit) 62 that stores various data and programs, and an image processing unit 63. An A / D converter 38 is provided at the output of the image sensor 26 in the endoscope 20, and the captured image signal is converted into digital data in the endoscope 20. This digital captured image signal is taken into the image processing unit 63 via the mounting unit 23a and subjected to the image processing described above. At this time, the image processing unit 63 performs image processing based on information from the light source control unit 59 (information indicating which light source is the illumination light source), and displays the processing result via the control unit 61 as a display unit. 53 and displayed on the external recording device 70.

  The control unit 61 has a built-in CCD driving unit 61a and switches the driving mode of the image sensor 26 when the white light source 55 is operated by the light source control unit 59 and when the excitation light source 56 is operated. have.

  1 is provided with a switching button 37, and when the endoscope operator transmits a light source switching instruction to the control unit 61 using the switching button 37, the control unit 61 performs light source control. The light source for causing the unit 59 to emit light is switched, and the drive mode of the image sensor 26 is switched.

  FIG. 5 is a schematic view of the surface of the solid-state imaging device 26 which is an interline CCD. In the illustrated solid-state imaging device 26, a plurality of pixels (photodiodes: PD) 80 are arranged in a square lattice pattern on the surface of a semiconductor substrate, and a vertical charge transfer path (VCCD) 81 along each pixel column. A horizontal charge transfer path (HCCD) 82 is formed along the transfer direction end of each vertical charge transfer path 81, and the charge of the signal charge transferred to the transfer direction end of the horizontal charge transfer path 82 is formed. An amplifier 83 that outputs a voltage value signal corresponding to the amount as a captured image signal is provided.

  In the solid-state imaging device 26 in the example shown in the figure, two vertical transfer electrodes are provided per pixel, and one of the two is an electrode that is also used as a readout electrode (84). FIG. 6 is a diagram showing the relationship between the pixels of the solid-state imaging device 26 and the vertical transfer electrodes V1 to V6. The vertical transfer electrodes V1, V3, and V5 are also used as readout electrodes.

  The solid-state image sensor 26 of this embodiment is driven by three-field readout. That is, the signal charge (captured image signal) for one screen is output in three steps. First, a signal charge is read out from the pixel indicated as “PD1” in FIG. 5 to the vertical charge transfer path 81, transferred to the horizontal charge transfer path 82, and then transferred to the amplifier 83 through the horizontal charge transfer path 82. Output a signal. Next, the signal charge of the pixel of “PD2” is output in the same manner, and finally the signal charge of the pixel of “PD3” is output.

  FIG. 7 is a flowchart illustrating a switching process procedure of the image sensor driving mode performed by the control unit 61 of FIG. First, it is determined whether or not to observe the observation site with special light (step S1). If the observation is not special light observation, a bright image can be picked up by using the light emitted from the white light source 55 in FIG. 4 as illumination light. Therefore, the process proceeds to step S2, and the image pickup device 26 is driven in a normal transfer mode to be described later. Exit.

  In the case of special light observation, in other words, the emission light (excitation light) of the excitation light source 56 in FIG. Absent. Therefore, in the case of special light observation, the process proceeds to step S3, the image pickup device 26 is driven in an empty packet transfer mode, which will be described in detail later, and this process ends.

  FIG. 8 is a potential transition diagram of the vertical charge transfer path for explaining the normal transfer mode performed in step S2 of FIG. FIG. 8A shows the vertical transfer electrodes V1 to V6, and FIGS. 8B to 8N show potential wells (potential wells) that change according to transfer pulses applied to the vertical transfer electrodes V1 to V6. And its transition state.

  The state shown in FIG. 8B is a state in which the accumulated charge of the pixel PD1 in FIG. 5 is read into the potential well formed under the readout electrode / transfer electrode V1 and the transfer is started in the direction of the horizontal charge transfer path 82. Show. In this normal transfer mode, white light with high illuminance is used as illumination light instead of special light, so that the amount of signal charge to be transferred is large (the number of electrons is large).

  8 (c) → (d) → (e) → (f) → (g) → (h) → (i) → (j) → (k) → (l) → (m) The potential well (signal packet) into which charges are charged is transferred in the direction of the horizontal charge transfer path 82 by repeating expansion and contraction in the order of two electrodes of the vertical transfer electrode film → one electrode → two electrodes → one electrode →. .

  Then, as shown in FIG. 8 (n), when a signal packet comes under the next vertical electrode V1, the transfer in the vertical direction is stopped to enter a standby state, and during this standby state, the horizontal charge transfer path The signal charge is transferred and output from the amplifier 83. After the output from the amplifier 83 is completed, the signal charge for one row is transferred to the horizontal charge transfer path 82 by repeating the transfer of FIGS. 8B to 8N. This horizontal charge transfer path The signal charge on 82 is transferred and output during standby on the vertical charge transfer path.

  Since the normal transfer mode is a transfer when the amount of signal charge is large, the capacity of the signal packet is not increased as described above, instead of 2 electrodes → 1 electrode → 2 electrodes →. Then, it may be carried out as 3 electrodes → 2 electrodes → 3 electrodes → 2 electrodes →.

  FIG. 9 is a potential transition diagram of the vertical charge transfer path for explaining the empty packet transfer mode performed in step S3 of FIG. FIG. 9A is the same as FIG.

  The state shown in FIG. 9B is a state in which the accumulated charge of the pixel PD1 in FIG. 5 is read into the potential well formed under the readout electrode / transfer electrode V1 and the transfer is started in the direction of the horizontal charge transfer path 82. Show.

  This empty packet transfer mode is a transfer mode for transferring a signal charge obtained by irradiating special light as illumination light, in this example, excitation light, and the image pickup device receiving fluorescence emitted from the observation site by itself. . Since the self-generated fluorescence is weak light, the amount of signal charge obtained is extremely small, and therefore the amount of signal charge to be transferred is small (the number of electrons is small).

  Hereinafter, in the same manner as described with reference to FIG. 8, the potential well (signal packet) containing the signal charge is expanded and contracted as follows: 2 electrodes of the vertical transfer electrode film → 1 electrode → 2 electrodes → 1 electrode → Is repeated in the direction of the horizontal charge transfer path 82. Before that, the voltage is applied to the vertical transfer electrode V4 by applying a voltage to the vertical transfer electrode V4 in FIG. 9C next to FIG. 9B. The empty packet 90 is formed. That is, the signal packet 91 and the empty packet 90 in which signal charges are put are alternately arranged on the vertical charge transfer path 81.

  Thereafter, as shown in FIG. 9 (d) → (e) → (f) → (g) → (h) → (i) → (j) → (k) → (l) → (m) → (o) Until the packet 91 comes to a position below the electrode V1, both the signal packet 91 and the empty packet 90 are repeatedly expanded and contracted in the order of 2 electrodes → 1 electrode → 2 electrodes →.

  When the signal packet 91 comes under the electrode V1 (FIG. 9 (o)), the signal charge described above enters a standby state, and the signal charge is transferred and output through the horizontal charge transfer path. Even in this standby state, The transfer operation of the empty packet 90 continues (FIG. 9 (p) to FIG. 9 (t)). The transfer operation of the empty packet 90 ends when the empty packet 90 joins the signal packet 91 in the preceding stage in the transfer direction.

  Thereafter, after the transfer and output operations in the horizontal charge transfer path are completed, the transfer of signal packets in the vertical charge transfer path 81 (FIGS. 9B to 9T) is started again.

  In the empty packet transfer mode, the signal charge amount is extremely small, and even if a slight transfer omission occurs, the image quality at the observation site is degraded. However, as in the present embodiment, the empty packet 90 is formed and transferred at the time of transfer on the vertical charge transfer path, and when the signal packet 91 is set in the standby state, the empty packet 90 is transferred in the preceding stage. By joining the packet 91, it is possible to reduce transfer leakage.

  For example, it is assumed that a signal charge transfer leak occurs in a certain signal packet. This transfer leakage charge is picked up and transferred to an empty packet 92 transferred at a later stage, as shown in FIG. 9 (k). Since this empty packet 92 is merged with the preceding signal packet 93 that caused the transfer leakage, the transfer leakage is avoided.

  FIG. 10 is an explanatory diagram of an empty packet transfer mode according to another embodiment of the present invention. In the empty packet transfer mode described with reference to FIG. 9, as shown in FIG. 10A, empty packets 90 having the same capacity as the signal packets 91 are formed and transferred between the signal packets 91. However, the capacity of the empty packet 90 may be larger than that of the signal packet 91 as shown in FIG. It may be configured to switch between the small-capacity empty packet in FIG. 10A and the large-capacity empty packet in FIG.

  FIG. 11A is a flowchart showing a processing procedure for switching the capacity of the empty packet according to the photographing illuminance. First, the imaging illuminance of the observation site is measured, and it is determined whether or not the measured illuminance is lower than the threshold illuminance (step S10). If the measured illuminance is higher than the threshold illuminance, the process proceeds to step S11, and an empty packet transfer mode for forming a small capacity empty packet is selected.

  As a result of the determination in step S10, if the measured illuminance is lower than the threshold illuminance, the amount of signal charge is so small that image quality deterioration is severe even with a small amount of transfer leakage, so that the possibility of picking up transfer leakage charge is increased. An empty packet transfer mode for forming a capacity empty packet is selected (step S12).

  The illuminance may be measured by mounting an illuminance detection sensor on the endoscope distal end portion 25. However, since the signal charge amount (output signal amount) decreases at low illuminance, the signal charge amount is a threshold value. You may judge indirectly by whether it becomes below. This determination can be made by measuring the signal amount of the picked-up image signal output from the image sensor in the moving image state and determining the signal amount of the previous frame or the frame before the previous frame.

  The above embodiment is an embodiment in which one empty packet is formed between the signal packets 91 and transferred. However, as shown in FIG. In this case, two empty packets 90 may be formed and transferred, and a plurality of empty packets 90 may be joined together with the preceding signal packet 91 when the standby state is reached. In FIG. 11A, the capacity of empty packets is switched depending on the photographing illuminance. Instead, as shown in FIG. 11B, the number of empty packets can be switched depending on the photographing illuminance. is there. When the measured illuminance is lower than the threshold illuminance, transfer is performed in a mode in which the number of empty packets is increased.

  The reason for merging empty packets when waiting for a signal packet is to counter dark current. This is because if the empty packet is made to wait on the vertical charge transfer path as an empty packet without joining the signal packet, there is a high possibility that dark current will enter the empty packet.

  It is also possible to collect this dark current with an empty packet prepared separately from an empty packet for collecting transfer leakage charge. In the embodiment of FIG. 10D, a plurality (two in the illustrated example) of empty packets 95 and 96 are formed between the signal packets 91, and the empty packet 96 preceding immediately before the subsequent signal packet 91 is changed to dark current. An empty packet for collection is used, and an empty packet that precedes the dark current collection empty packet 96 and follows the preceding signal packet 91 is an empty packet for collecting transfer leakage charges.

  The empty packet 95 for collecting the transfer leakage charge is joined to the preceding signal packet while waiting for the signal packet 91, but the empty packet 96 for collecting the dark current is always joined as an independent empty packet 96 without being joined. Even when the signal packet 91 is on standby, it is made to wait on the vertical charge transfer path 81.

  With this configuration, the dark current collecting empty packet 96 collects the dark current and smear charge on the vertical charge transfer path 81 prior to the subsequent signal packet 91, and therefore the dark current and smear charge in the signal packet 91 are collected. Is less likely to mix. The charges (dark current, smear) collected by the dark current collecting empty packet 96 are transferred and discarded separately from the signal charge through the horizontal charge transfer path. Alternatively, it is discarded to the semiconductor substrate side through a drain mechanism provided alongside the horizontal charge transfer path.

  FIG. 12 is a schematic view of the surface of the solid-state imaging device 100 having a pixel arrangement different from that in FIG. A plurality of photodiodes (pixels) 101 are arranged in a two-dimensional array on the surface of the semiconductor substrate of the solid-state imaging device 100, and a vertical charge transfer path (VCCD) 102 is formed along each pixel column. A horizontal charge transfer path (HCCD) 104 is formed along the transfer direction end of the charge transfer path 102, and a voltage value signal corresponding to the amount of signal charge transferred is imaged at the output end of the horizontal charge transfer path 104. An amplifier 105 that outputs an image signal is provided.

  In the solid-state imaging device 100 of the present embodiment, each pixel 101 is formed by shifting even-numbered pixel rows by 1/2 pixel pitch with respect to odd-numbered pixel rows, and has a so-called honeycomb pixel array.

  R, G, and B described on each pixel 101 in the figure indicate color filters (red, green, and blue), and an arrow that is illustrated diagonally downward to the left from each pixel 101 is adjacent to that pixel 101. The direction in which signal charges are read out to the vertical charge transfer path 102 is shown.

  The vertical charge transfer path 102 is composed of a buried channel (not shown) formed on the surface portion of the semiconductor substrate and a transfer electrode made of a polysilicon film formed thereon via a gate insulating film. The state in which the electrodes are formed in multiple stages in the vertical direction is shown.

  Each vertical transfer electrode is provided continuously in one horizontal row, and a transfer pulse is applied from the left and right ends (left end in the illustrated example). The solid-state imaging device 100 in the illustrated example has a wiring connection configuration driven by 16 phases, and transfer pulses of φV1 to φV16 are applied to the vertical transfer electrodes V1 to V16, respectively. That is, the transfer pulse φVi is applied to the transfer electrode Vi. The transfer pulses φV1 to φV16 are generated by the CCD driving unit 61a4 according to the instruction of the control unit 61 in FIG. 4 and supplied to the corresponding transfer electrodes of the solid-state imaging device 100.

  The terms “vertical” and “horizontal” are used for explanation, but this means “one direction” along the surface of the semiconductor substrate on which the solid-state imaging device is formed, “a direction substantially perpendicular to this one direction”. It just means that. The same applies to the description of FIG.

  FIG. 13 is an explanatory diagram of a driving method of the solid-state imaging device, and is a diagram illustrating a change in state of the vertical charge transfer path driven by the vertical transfer pulses φV1 to φV16. The upper row shows how signal packets and empty packets are formed and transferred, and the lower row shows the waveform (applied voltage) of the transfer pulse to each transfer electrode that realizes the upper state.

  In the figure, an electrode to which a low voltage L (for example, −8 V) is applied is a VL electrode, an electrode to which a medium voltage M (for example, ± 0 V) is applied is a VM electrode, and an electrode to which a medium voltage is applied A potential packet is formed below.

At time t1 shown in the figure, the electrodes V5 to V9 are VM electrodes, and a potential packet (blacked portion) is formed below this. A signal charge is put in this potential packet to become a signal packet 121. At the same time, the electrodes V1 and V2 are also VM electrodes, and a potential packet (shaded portion) is formed thereunder. This potential packet is an empty packet 122 in which the detection charge of the pixel 101 is not put.

  At the next time t2, the forming electrode (VM electrode) of the signal packet 21 extends to the horizontal charge transfer path side by V5 to V10 and one electrode, and at the next time t3, the forming electrode of the signal packet 21 is opposite to V6 to V10. The horizontal charge transfer path side shrinks by one electrode. As a result, the signal packet 121 is transferred to the horizontal charge transfer path side for one electrode.

  At the same time, at time t2, the formation electrode of the empty packet 122 extends to the horizontal charge transfer path side by V1 to V3 and one electrode, and at the next time t3, the formation electrode of the empty packet 122 becomes V2, V3 and the anti-horizontal charge. The transfer path side shrinks by one electrode. Thus, simultaneously with the expansion and contraction of the signal packet 121, the empty packet 122 is also expanded and contracted by one electrode and transferred to the horizontal charge transfer path side.

  In this way, the signal packet 121 is transferred in the direction of the horizontal charge transfer path, and the empty packet 122 is transferred at an interval of two electrodes in the subsequent stage. The remaining (transfer leakage) charge is picked up by the empty packet 122 and transferred in the direction of the horizontal charge transfer path.

  At time t11, the signal packet 121 has five electrodes V10 to V14. In this state, the signal charge of the portion of the signal packet (not shown in FIG. 13) that has been transferred just before the horizontal charge transfer path is transferred to the horizontal charge transfer path. The horizontal charge transfer path transfers the received signal charge to the output amplifier side based on the horizontal transfer pulses φH1 and φH2.

  While the horizontal charge transfer paths φH1 and φH2 are applied to the horizontal charge transfer path and the horizontal charge transfer path is being driven to transfer, the vertical charge transfer path is maintained in a stopped state, and the electrodes V10 to V14 of the signal packet 121 are formed. State is maintained.

  When entering this state, that is, at time t 11, the signal packet 121 enters the stopped state, but at time t 12, t 13, t 14, t 15, t 16, the transfer of the empty packet 122 is continued, and the empty packet 122 becomes the signal packet 121. After joining, transfer of the empty packet 122 is also stopped. That is, the transfer residual charge picked up by the transfer of the empty packet 122 is mixed with the original signal charge in the signal packet 121, and the transfer efficiency is effectively increased.

  While the horizontal charge transfer path is being driven to transfer, the presence of the empty packet 122 disappears, and only the signal packet 121 enters a standby state on the vertical charge transfer path. When the transfer drive of the horizontal charge transfer path is completed and the transfer of the signal packet 121 is started at time ta (left end side in FIG. 3), the electrodes V7 and V8 are made VM electrodes immediately before that to form an empty packet 122. Thereafter, in the same manner as described above, in parallel with the transfer of the signal packet 121, the empty packet 122 is synchronously transferred to the immediately subsequent stage.

  As described above, in the present embodiment, in the horizontal blanking period (= vertical transfer period), the empty packet 122 is formed immediately after each of the many signal packets 121 formed in the vertical charge transfer path, and is vertically Since the charge transfer path is driven, the transfer efficiency is effectively improved and the image quality of the captured image can be improved.

  In addition, immediately before the start of transfer driving of the horizontal charge transfer path, the empty packet 122 is merged with the signal packet 121 that is the generation source of the transfer remaining, and the horizontal charge transfer path is being driven, that is, the vertical charge transfer path is stopped. Since the empty packet 122 is lost, it is possible to further improve the image quality.

  The reason is as described above. When the empty packet 122 is present while the vertical charge transfer path is stopped, dark current noise charge is accumulated in the empty packet 122, and this dark current noise is mixed in the signal charge. This is because the S / N of the captured image is deteriorated.

  FIG. 14 is an explanatory diagram of a driving method according to another embodiment of the present invention, and the way of viewing the drawing is the same as FIG. In the embodiment described with reference to FIG. 13, one empty packet 22 is transferred to the subsequent stage immediately after the signal packet 121, the remaining transfer charge is collected by one empty packet 122, and this is combined with the signal packet 121. .

  On the other hand, in this embodiment, as in FIG. 10C, another empty packet 123 is formed after the empty packet 122 and transferred. That is, the remaining transfer of the signal packet 121 is picked up by the empty packet 122, and the charge transfer remaining picked up by the empty packet is picked up by the second empty packet 123. This makes it possible to further improve the effective transfer efficiency.

  Of course, also in this case, immediately before the horizontal charge transfer path is driven (= immediately before the vertical charge transfer path is stopped), the two empty packets 122 and 123 are joined together to the signal packet 121 as shown in the figure, and the vertical charge There is no empty packet while the transfer path is stopped. That is, only the signal packet 121 is assumed.

  FIG. 15 is an explanatory diagram of a driving method according to still another embodiment of the present invention. The way of viewing the figure is the same as in FIG. As shown in FIG. 15A, when the number of electrodes forming the signal packet 121 is increased so that the capacity is “large” and a large amount of signal charge can be transferred, the number of electrodes of the empty packet 122 cannot be increased. Occurs. However, when the amount of signal charge is large (when driving with a large amount of saturation), there is no problem even if the transfer efficiency is slightly low.

  However, when the signal charge amount is small (when driving with a small saturation amount), for example, when photographing with high ISO sensitivity due to a special light environment, the signal charge amount itself is small. In this case, a wide signal packet (large transfer capacity) 121 as shown in FIG. 15A is formed and transferred, and the number of empty packet electrodes in the subsequent stage is kept small (transfer capacity is small). In this case, a slight decrease in transfer efficiency leads to a large decrease in image quality.

  Therefore, in the present embodiment, as shown in FIG. 15B, when the amount of signal charge itself decreases as in shooting with high ISO sensitivity, that is, at low sensitivity and high gain, the number of electrodes of the signal packet 121 is reduced. (Transfer capacity is reduced), and instead, the number of electrodes forming the empty packet 122 is increased (transfer capacity is increased). As a result, a large amount of transfer residue can be collected, transfer efficiency can be improved even when a small amount of signal charge is transferred, and image quality at high ISO sensitivity can be improved.

  Although FIG. 15B illustrates an example in which the transfer capacity of one empty packet is increased, similarly to FIG. 14, two empty packets are formed in the subsequent stage of one signal packet, and effectively empty. The packet transfer capacity may be increased.

  FIG. 16 is a schematic view of the surface of a CCD solid-state imaging device according to another embodiment. The CCD solid-state imaging device described above is an interline type. However, the CCD solid-state imaging device 200 of this embodiment is a frame transfer (FT) type, and is continuous in the vertical direction with the light receiving unit 201 of the semiconductor substrate. Thus, a plurality of pixels 202 are formed, and a plurality of continuous pixel columns form a vertical charge transfer path along the pixel columns as they are.

  A storage unit 205 is provided at a lower portion in the vertical direction of the light receiving unit 201. The configuration of the storage unit 205 is substantially the same as that of the light receiving unit 201, except that the storage unit 205 is covered with a light shielding film 206.

  A horizontal charge transfer path 207 is provided along the transfer direction end of the plurality of vertical charge transfer paths, and an output amplifier 208 is provided at the transfer direction end of the horizontal charge transfer path 207 at the lower part of the accumulation unit 205 in the vertical direction. It has been.

  FIG. 17A is a schematic cross-sectional view along the pixel column shown in FIG. An n region corresponding to each pixel is provided on the semiconductor substrate 210 at a slight distance. Transfer electrodes 212 and 214 are stacked on the surface of the semiconductor substrate 210 via a gate insulating film 211.

  The first layer transfer electrode 212 is provided above the n region corresponding to the pixel, and the second layer transfer electrode 214 adjacent to the first layer transfer electrode 212 with the insulating film 213 interposed between the pixels (n region). Are stacked in the upper position. The transfer electrode 212 of the first layer and the transfer electrode 214 of the second layer are slightly overlapped at the boundary portion so that an overlapping portion is generated. Although the transfer electrodes 212 and 214 may have a single-layer film structure, there is a possibility that transfer leakage charges may remain in a narrow insulating portion between the transfer electrode 212 and the transfer electrode 214. It is better to provide the overlapping portion between them.

  A high-concentration p region 215 is provided at each position where the transfer electrodes 212 and 214 are in contact with the gate insulating film 211 of the semiconductor substrate 210 at the subsequent stage in the transfer direction of the vertical charge transfer path. As a result, when a voltage for forming a potential well is applied to each transfer electrode 212, 214, it is possible to form a deep potential well stepwise in the transfer direction.

  FIG. 17B shows the state of the potential well formed under each electrode when the first voltage is applied to the first-layer transfer electrode 212 and the second voltage is applied to the second-layer transfer electrode 214. FIG. A deep potential well is formed under the first layer transfer electrode 212, and a signal charge 220 corresponding to the amount of received light is accumulated therein.

  FIG. 18 is a diagram showing a normal transfer mode (step S2 in FIG. 7) in which the signal charges accumulated as shown in FIG. 17B are transferred to the accumulation unit 205. 18 (a) = FIG. 17 (a), and FIG. 18 (c) = FIG. 17 (b). FIG. 18C (the first voltage is applied to the transfer electrode 212, the second voltage is applied to the transfer electrode 214), and the state of FIG. 18B (the second voltage applied to the transfer electrode 212, the second voltage is applied to the transfer electrode 214). 1), the signal charge 220 is transferred in the vertical direction.

  19 and 20 are diagrams showing a state of signal charge transfer (empty packet transfer mode S3 in FIG. 7) obtained in a special light environment. As shown in FIG. 19B, the amount of the signal charge 230 obtained in the special light environment is extremely small. For example, the odd-numbered potential well is transferred by one stage in the vertical direction and merged with the even-numbered potential well. The signal charge is added by two pixels.

  As a result, a space for forming the empty packet 231 is formed at the odd-numbered potential well, and the signal packet, the empty packet, the signal packet, the empty packet,... Are alternately arranged on the vertical charge transfer path. In this state, the signal packet containing the signal charge 230 obtained by adding two pixels and the empty packet 231 are transferred in the vertical direction as shown in FIGS. The transferred leakage charge is picked up by the empty packet 231 that is transferred immediately thereafter.

  The signal packet 230 transferred to the storage unit 205 temporarily enters a standby state, but the empty packet 231 continues to be transferred by one stage and merges with the preceding signal packet 230. As a result, the transfer efficiency in the FT-CCD can be improved. When transferring from the storage unit 205 to the horizontal charge transfer path 207, transfer efficiency is improved by transferring empty packets in the same manner as described above.

  The empty packet transfer mode described with reference to FIGS. 19 and 20 is an embodiment corresponding to FIG. 10A, and signal packets and empty packets are alternately arranged on the vertical charge transfer path. If three-pixel addition is performed instead of the two-pixel addition described in FIG. 19, two empty packets can be formed between signal packets. In this case, the embodiment corresponds to FIG. 10C, and it is possible to improve transfer efficiency by transferring two empty packets 231 and joining the waiting signal packet 230.

  Alternatively, it is possible to improve the S / N ratio by using the subsequent empty packet of two empty packets formed by adding three pixels as the dark current collecting empty packet preceding the subsequent signal packet.

  FIG. 21 is a functional block diagram of an embodiment of the endoscope apparatus instead of FIG. Since it is basically the same as the configuration of FIG. The endoscope apparatus according to the present embodiment includes a red (R) light source 71, a green (G) light source 72, and a blue light source 73 without using the white light source 57, and is connected to the multiplexer 57. This is different from FIG.

  FIG. 22 is a diagram showing a filter arrangement of the image sensor 26 used in the endoscope apparatus of FIG. In the imaging device of FIG. 22, each pixel 301 is arranged in a square lattice, a vertical charge transfer path (VCCD) 302 is formed along the pixel column, and horizontal along the transfer direction end of each vertical charge transfer path 302. A charge transfer path (HCCD) 303 is formed, and an amplifier 304 that outputs a voltage value signal corresponding to the transferred signal charge amount as a picked-up image signal is provided at the transfer direction end of the horizontal charge transfer path 303. Yes.

  The color filters of red (R), green (G), and blue (B) are stacked on each pixel of the image sensor of FIG. 12, but in the image sensor of FIG. 22, a transparent layer W is formed on each pixel. Laminated. The transparent layer W is optically transparent with respect to each of illumination light from the red light source 71, illumination light from the green light source 72, illumination light from the blue light source 73, and fluorescence emitted by the observation site. Is a layer.

  In the endoscope apparatus having such a configuration, the light source control unit 59 cyclically operates the red light source 71, the green light source 72, and the blue light source 73, and the observation site is changed from red light → green light → blue light → Illuminate cyclically with red, green, and so on. The image pickup device 26 employs a frame sequential imaging method in which a captured image for each color light is captured and a captured image signal is output to the image processing unit 63 for each color light.

  In the endoscope apparatus shown in FIG. 21, an image sensor 26 equipped with color filters RGB can be used. In this case, the color filter array may be a three-primary color filter RGB in a Bayer array as shown in FIG. The light source control unit 59 of the endoscope apparatus generates white light by causing the R light source 71, the G light source 72, and the B light source 73 to emit light at the same time and combine them with the combiner 57, thereby generating white light. Use illumination light.

  However, in the primary color filter, since the light use efficiency of each pixel is 1/3 (for example, the R filter does not pass G light and B light), as shown in FIG. It is preferable to use a color filter.

  As described above, the imaging of the observation site by the endoscope apparatus may be performed under a bright illumination light or in a dark special light environment. If only photographing under bright illumination light is considered, an image sensor that is equipped with a color filter as shown in FIGS. 23A and 23B and can photograph a color image is preferable. However, when photographing with special light is performed with this image sensor, the image sensor can detect only light that has passed through a color filter among weak special light, which is disadvantageous for photographing in a special light environment.

  Therefore, it is preferable to use the image sensor shown in FIG. In this imaging device 350, each pixel 301 is arranged in a square lattice, and a color filter is mounted on each pixel of the odd-numbered pixel column of each pixel column, and a transparent layer W is stacked on the even-numbered pixel column. Yes. The color filter array may be the Bayer array shown in FIG. 23A or the complementary color system color filter array shown in FIG.

  When shooting under bright illumination light, a color image of the observation site is generated with the detection signal of each pixel equipped with a color filter, and when shooting in a special light environment, it is transparent. A luminance image of the observation region is generated by the detection signal of each pixel in which the layer W is stacked. This makes it possible to obtain a high quality image even with weak special light.

  The pixel array for laminating the transparent layer W and the pixel array for laminating the color filters are not limited to the embodiment of FIG. For example, as shown in an image sensor 360 in FIG. 25, a configuration in which a transparent layer W is stacked on each pixel at the checkered position and a color filter is stacked on each remaining pixel at the checkered position. 24 and 25 show examples in which each pixel is arranged in a square lattice, but the transparent layers W are arranged in a mosaic manner even if each pixel has a so-called honeycomb pixel arrangement as shown in FIG. Thus, the same effect can be obtained.

  FIG. 26 is a functional block diagram of still another embodiment of the endoscope apparatus instead of FIG. Since it is basically the same as the configuration of FIG. The endoscope apparatus of this embodiment is different in that a fluorescent light source 75 is provided instead of the excitation light source 56. The fluorescent light source may be configured to, for example, incorporate a phosphor, and output the fluorescence emitted by irradiating the phosphor with a laser beam or the like to the multiplexer 57.

  In addition, although various embodiment mentioned above was demonstrated as separate embodiment, you may be set as embodiment which combined these several embodiment. For example, the color filter array of the FT-CCD shown in FIG. 16 may be as shown in FIGS.

  As described above, the endoscope apparatus and the solid-state imaging device driving method according to the embodiment are arranged along a plurality of pixels arranged in a two-dimensional array on a semiconductor substrate and a plurality of pixel columns composed of the pixels. When driving a solid-state imaging device having a plurality of vertical charge transfer paths formed in the endoscope and incorporated in the distal end portion of the endoscope, a signal packet storing a signal charge detected by the pixel is used as the vertical charge transfer path. At the same time as forming and transferring, an empty packet for picking up the remaining transfer charge generated by the transfer of the signal packet is formed and transferred after the transfer direction of the signal packet at the time of photographing in a special light environment.

  In addition, the endoscope apparatus and the solid-state image sensor driving method thereof according to the embodiment are characterized in that the empty packet is not formed and transferred at the time of photographing that is not under the special light environment.

  In addition, in the endoscope apparatus and the solid-state imaging device driving method according to the embodiment, the vertical charge transfer path is used when the horizontal charge transfer path formed along the transfer direction ends of the plurality of vertical charge transfer paths is driven to transfer. The transfer of the signal packet is stopped and the empty packet is merged with the signal packet that is the generation source of the transfer remaining before the transfer of the horizontal charge transfer path is started.

  In addition, a plurality of the empty packets of the endoscope apparatus and the solid-state imaging device driving method according to the embodiment are provided between a signal packet that is a generation source of a transfer residue and a next signal packet.

  In addition, the endoscope apparatus and the solid-state imaging device driving method according to the embodiment reduce the capacity of the empty packet and reduce the signal charge under the special light environment and the imaging condition where the signal charge amount exceeds a predetermined threshold. It is characterized in that the capacity of the empty packet is increased under imaging conditions where the amount is small.

  In addition, in the endoscope apparatus and the solid-state image sensor driving method of the embodiment, whether the signal charge amount is larger or smaller than the predetermined threshold depends on whether the output signal of the solid-state image sensor obtained in the previous frame or the previous frame It is characterized by judging by.

  In addition, in the endoscope apparatus and the solid-state image sensor driving method of the embodiment, each pixel of the solid-state image sensor is not mounted with a color filter, and the solid-state image sensor emits light in the endoscope control unit. It is characterized in that each color of a plurality of colors of photographing light introduced to the distal end portion of the endoscope is driven in a frame sequential manner.

  In addition, the endoscope device of the embodiment and the solid-state image pickup device of the solid-state image pickup device driving method are provided with a color filter mounted pixel and a color filter non-mounted pixel, and in the shooting under the special light environment, An image of an observation site is generated from a detection signal of a pixel not equipped with a color filter.

  In addition, the endoscope device of the embodiment and the solid-state image sensor of the solid-state image sensor driving method are interline CCDs.

  Further, the solid-state image pickup device of the endoscope apparatus and the solid-state image pickup device driving method of the embodiment is a frame transfer type CCD, and the signal charges of a plurality of pixels are added in the transfer direction of the vertical charge transfer path that is also used as the pixel. Thus, a space for forming the empty packet is secured.

  Further, the imaging in the special light environment of the endoscope apparatus and the solid-state imaging device driving method of the embodiment is imaging with fluorescence emitted from the endoscope control unit and irradiated to an observation site. .

  Further, the imaging in the special light environment of the endoscope apparatus and the solid-state imaging device driving method of the embodiment is self-luminous at the observation site by the excitation light emitted from the endoscope control unit and irradiated on the observation site. It is characterized by photographing with fluorescence.

  In addition, in the endoscope apparatus and the solid-state image sensor driving method of the embodiment, the charge collected by the dark current collection packet is formed by forming a dark current collection packet separately from the empty packet immediately before the transfer direction of the signal packet. It is characterized by discarding.

  According to the embodiments described above, the amount of signal charge obtained by shooting in a special light environment is very small, but an empty packet is sent after the signal packet, and the remaining transfer charge generated in the signal packet is collected by the empty packet. Therefore, it is possible to increase transfer efficiency and obtain an image of an observation site with high image quality.

  Since the imaging apparatus according to the present invention is equipped with a solid-state imaging device driving unit suitable for photographing in a special light environment, it becomes possible to perform high-quality observation of an affected area using self-emitted fluorescence and the like in an endoscope. It is useful to apply.

DESCRIPTION OF SYMBOLS 10 Endoscope 20 Endoscope 25 Endoscope end part 26,100,200,350,360 CCD type solid-state image sensor 34 Shooting lens 50 Peripheral device 51 Processor (endoscope control part)
52 light source device 53 monitor device 55 white light source 56 excitation light source 59 light source control unit 61 control unit 61a CCD drive unit 80, 101, 202, 301 pixel (photodiode)
81, 102, 302 Vertical charge transfer path (VCCD)
90, 122, 123 Empty packet 91, 121 Signal packet

Claims (26)

A plurality of pixels arranged in a two-dimensional array on a semiconductor substrate, and a plurality of vertical charge transfer paths formed along a plurality of pixel columns composed of the pixels, are incorporated in the distal end portion of the endoscope. A solid-state imaging device,
A signal packet that contains the signal charge detected by the pixel is formed and transferred to the vertical charge transfer path, and the remaining transfer generated by the transfer of the signal packet at a later stage of the signal packet transfer direction when shooting in a special light environment An endoscope apparatus comprising: an endoscope control unit that forms and transfers an empty packet for picking up an electric charge.   2. The endoscope apparatus according to claim 1, wherein the endoscope control unit does not form and transfer the empty packet at the time of photographing that is not under the special light environment.   The endoscope apparatus according to claim 1 or 2, wherein the solid-state imaging device includes a horizontal charge transfer path formed along a transfer direction end of the plurality of vertical charge transfer paths, The endoscope control unit stops the transfer of the signal packet on the vertical charge transfer path when driving the horizontal charge transfer path and transfers the empty packet to the remaining transfer before starting the transfer of the horizontal charge transfer path. An endoscope apparatus that joins the signal packet as a generation source.   The endoscope apparatus according to any one of claims 1 to 3, wherein a plurality of the empty packets are provided between a signal packet that is a generation source of a transfer residue and a next signal packet. Endoscopic device.   5. The endoscope apparatus according to claim 1, wherein the capacity of the empty packet is reduced under imaging conditions in which the signal charge amount is larger than a predetermined threshold value in the special light environment. An endoscope apparatus in which the capacity of the empty packet is increased under imaging conditions in which the signal charge amount is reduced and reduced.   6. The endoscope apparatus according to claim 5, wherein whether or not the signal charge amount is larger or smaller than the predetermined threshold is determined based on an output signal of the solid-state imaging device obtained in the previous frame or the previous frame. Endoscopic device.   The endoscope apparatus according to any one of claims 1 to 6, wherein each pixel of the solid-state image sensor is not mounted with a color filter, and the solid-state image sensor is installed in the endoscope control unit. An endoscope apparatus that is driven in a frame-sequential manner for each color of a plurality of colors of photographic light that is emitted by and introduced into the distal end portion of the endoscope.   The endoscope apparatus according to any one of claims 1 to 6, wherein the solid-state imaging device includes a color filter mounted pixel and a color filter non-mounted pixel, and the special imaging environment is used. An endoscope apparatus in which an image of an observation site is generated from a detection signal of a pixel not equipped with a color filter in the imaging of (2).   The endoscope apparatus according to any one of claims 1 to 8, wherein the solid-state imaging device is an interline CCD.   9. The endoscope apparatus according to claim 1, wherein the solid-state imaging device is a frame transfer type CCD, and a plurality of pixels are arranged in a transfer direction of a vertical charge transfer path that is also used as the pixel. An endoscopic apparatus that secures a space for forming the empty packet by adding the signal charges.   The endoscope apparatus according to any one of claims 1 to 10, wherein the photographing under the special light environment is photographing by fluorescence emitted from the endoscope control unit and irradiated to an observation site. An endoscopic device.   The endoscope apparatus according to any one of claims 1 to 10, wherein imaging in the special light environment is performed by excitation light emitted from the endoscope control unit and irradiated to an observation site. An endoscopic device that is photographing with fluorescence that is self-emitted at an observation site.   13. The endoscope apparatus according to claim 1, wherein a dark current collection packet is formed separately from the empty packet immediately before the signal packet is transferred in order to collect the dark current. An endoscope device that discards the charges collected in packets. A plurality of pixels arranged in a two-dimensional array on a semiconductor substrate, and a plurality of vertical charge transfer paths formed along a plurality of pixel columns composed of the pixels, are incorporated in the distal end portion of the endoscope. A solid-state imaging device driving method comprising:
A signal packet that contains the signal charge detected by the pixel is formed and transferred to the vertical charge transfer path, and the remaining transfer generated by the transfer of the signal packet at a later stage of the signal packet transfer direction when shooting in a special light environment A method for driving a solid-state imaging device of an endoscope apparatus that forms and transfers an empty packet for picking up an electric charge.   The solid-state image sensor driving method for an endoscope apparatus according to claim 14, wherein the empty packet is not formed and transferred when the photographing is not performed in the special light environment.   16. The solid-state image sensor driving method for an endoscope apparatus according to claim 14 or 15, wherein a horizontal charge transfer path formed along a transfer direction end of the plurality of vertical charge transfer paths is driven to transfer. The solid state of the endoscope apparatus that stops the transfer of the signal packet on the vertical charge transfer path and joins the empty packet to the signal packet that is the generation source of the transfer before the transfer of the horizontal charge transfer path is started. Image sensor driving method.   The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 16, wherein the empty packet includes a signal packet that is a generation source of a transfer residue and a next signal packet. A solid-state image sensor driving method for an endoscope apparatus provided in between.   The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 17, wherein the signal charge amount is larger than a predetermined threshold value in the special light environment. A method for driving a solid-state imaging device of an endoscope apparatus, wherein the capacity of the empty packet is increased and the capacity of the empty packet is increased under imaging conditions in which the amount of signal charge is reduced.   The solid-state image sensor driving method for an endoscope apparatus according to claim 18, wherein whether the signal charge amount is larger or smaller than the predetermined threshold is determined by the solid-state image sensor obtained in the previous frame or the previous frame. A method for driving a solid-state imaging device of an endoscope apparatus that is determined by an output signal.   The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 19, wherein each pixel of the solid-state image sensor is not mounted with a color filter, and the solid-state image sensor is A method for driving a solid-state imaging device of an endoscope apparatus in which each color of a plurality of colors of photographing light that is emitted within the endoscope control unit and introduced into the distal end portion of the endoscope is driven in a frame sequential manner.   The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 19, wherein the solid-state image sensor is provided with a color filter mounted pixel and a color filter non-mounted pixel. A method for driving a solid-state imaging element of an endoscope apparatus in which an image of an observation site is generated from a detection signal of a pixel not equipped with the color filter in photographing under the special light environment.   The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 21, wherein the solid-state image sensor is an interline CCD. .   The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 21, wherein the solid-state image sensor is a frame transfer type CCD, and a vertical charge transfer path also used as the pixel. A solid-state image sensor driving method for an endoscope apparatus that secures a space for forming the empty packet by adding signal charges of a plurality of pixels in the transfer direction.   The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 23, wherein the imaging under the special light environment is emitted by the endoscope control unit and is applied to an observation site. A method for driving a solid-state image sensor of an endoscope apparatus, which is photographing using irradiated fluorescence.   The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 23, wherein the imaging under the special light environment is emitted by the endoscope control unit and is applied to an observation site. A method for driving a solid-state image sensor of an endoscope apparatus, which is photographing by fluorescence emitted by self-emission at the observation site by irradiated excitation light.   26. The solid-state image sensor driving method for an endoscope apparatus according to any one of claims 14 to 25, wherein a dark current collection packet is formed separately from the empty packet immediately before a transfer direction of the signal packet. A solid-state image sensor driving method for an endoscope apparatus that discards charges collected by the dark current collecting packet.

Images