JP2008183049A - Imaging device, and capsule type endoscopic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device and a capsule type endoscopic camera photographing in more directions. <P>SOLUTION: The imaging device comprises a first imaging means, a second imaging means, a control means for selectively operating the first imaging means or the second imaging means, an image processing means for forming an image from imaging signals transmitted from the imaging means selected by the control means, and a transmitting means for radio-transmitting the image formed by the image processing means. The first imaging means comprises a first illumination light source, a first lens, and a first solid imaging element for imaging utilizing the first illumination light source and the first lens. The second imaging means comprises a second illumination light source, a second lens, and a second solid imaging element for imaging utilizing the second illumination light source and the second lens, and images an object in a direction different from the direction of imaging by the first imaging means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus, and more particularly, to an imaging apparatus using a solid-state imaging device and a capsule endoscope camera.

  A capsule endoscope camera using a solid-state imaging device such as a MOS image sensor or a CCD image sensor is known.

  Endoscopic cameras are used to observe where human eyes cannot reach. For example, an endoscopic camera is used for medical purposes such as observation of an internal surface of a human digestive organ or the like. In a general endoscopic camera, a tubular insertion portion is inserted into an observation target portion. An image sensor (solid-state imaging device) is disposed at the distal end of the insertion portion, and an optical fiber is connected to the solid-state imaging device. An image captured by the image sensor is transmitted to the operator side via an optical fiber. Since the observation target exists in a dark part such as the inside of a human body, a light source for illuminating the observation target is provided at the tip of the insertion part.

In recent years, as disclosed in Patent Document 1, for example, a capsule-type endoscopic camera has been developed and used for observation applications such as a human digestive organ. A capsule endoscope camera incorporates a solid-state imaging device, a light source, a drive circuit, a battery, and the like in a small capsule. The examinee swallows the capsule-type endoscopic camera. The swallowed capsule endoscope camera wirelessly transmits a captured image to the outside of the body while moving in the digestive system. Such a capsule-type endoscopic camera does not require an insertion part, and can reduce the suffering of the examinee due to the insertion of the insertion part.
JP 2006-755331 A (FIG. 1)

  However, the capsule endoscope camera according to the related art does not always capture an image in all directions (three-dimensional all directions) while traveling through an observation target, and can obtain an image in a specific direction and a deviation in the shooting direction. There are problems such as not. Therefore, there is a possibility that the observation target (stomach wall, intestinal wall, etc.) cannot be thoroughly inspected (inspection omission).

  An object of the present invention is to provide an imaging device and a capsule-type endoscopic camera that can photograph more directions.

  In order to solve the above-described problem, an imaging apparatus according to the present invention includes a first illumination light source, a first lens, and a first solid-state imaging device that captures an image using the first illumination light source and the first lens. 1 imaging means, a second illumination light source, a second lens, and a second solid-state imaging device that takes an image using the second illumination light source and the second lens, and the first imaging means An image from a second image pickup means for picking up images in different directions, a control means for selectively operating the first image pickup means and the second image pickup means, and an image pickup signal from the image pickup means selected by the control means And an image processing unit for transmitting the image formed by the image processing unit. According to this configuration, since the first imaging unit and the second imaging unit capture different directions, it is possible to capture images with more azimuths. Further, since the first imaging unit and the second imaging unit are selectively operated, power saving can be achieved.

  Here, the first imaging unit and the second imaging unit may image in opposite directions. According to this configuration, since the first imaging unit and the second imaging unit image in opposite directions, it is possible to efficiently capture images in more directions.

  Here, the first solid-state imaging device has a first enable terminal for accepting operation availability, the second solid-state imaging device has a second enable terminal for accepting operation availability, and the control means includes a first enable terminal. Each enable signal to the enable terminal and the second enable terminal may be selectively enabled. According to this configuration, the selection of the first imaging means and the second imaging means can be easily controlled by enabling the respective enable signals.

  Here, the control unit may alternately operate the first imaging unit and the second imaging unit. According to this configuration, when the first imaging unit and the second imaging unit are arranged symmetrically with respect to the center of gravity position of the imaging apparatus, the imaging direction by the first imaging unit and the second The balance with the imaging direction by the imaging means can be made uniform.

  Here, the control means may be operated so as to make the selection times of the first imaging means and the second imaging means non-equal. According to this configuration, when the first imaging unit and the second imaging unit are arranged asymmetrically with respect to the center of gravity of the imaging device, the first imaging unit and the second imaging unit By making the number of selection times non-uniform, it is possible to adjust the balance between the imaging direction by the first imaging unit and the imaging direction by the second imaging unit. Alternatively, when the first imaging means and the second imaging means are arranged symmetrically with respect to the center of gravity position of the imaging device, the imaging orientation by the first imaging means and the second imaging means The balance with the imaging direction can be biased.

  Here, the control means may supply a drive signal common to the first solid-state image sensor and the second solid-state image sensor. According to this configuration, since the drive signals other than the enable signals of the first imaging unit and the second imaging unit are common, the configuration of the control unit can be simplified.

  Here, the control means selectively operates the first solid-state imaging device and the second solid-state imaging device in the first mode and the second mode, and in the first mode, the first solid-state imaging device and the second solid-state imaging device. In the second mode, an operation clock signal having the same frequency as that of the first mode is inserted into the first solid-state image sensor and the second solid-state image sensor. And a second idle period longer than the first idle period may be inserted between the frame imaging periods of the first solid-state image sensor and the second solid-state image sensor. According to this configuration, the first mode (normal frame rate) and the second mode (low frame rate) can be arbitrarily set without changing the frequency of the operation clock signal.

  Here, each of the first solid-state imaging device and the second solid-state imaging device has first timing signal generating means for generating an imaging timing signal based on the first operation clock signal, and a frequency lower than that of the first operation clock signal. A second timing signal generating means for generating an imaging timing signal having at least the same exposure period as the first timing signal generating means based on the second operation clock signal, and the operation clock signal is the first operation clock signal. Selecting means for selecting one of the imaging timing signal from the first timing signal generating means and the imaging timing signal from the second timing signal generating means in accordance with a signal indicating whether it is the second operation clock signal or You may make it provide. According to this configuration, the frequency of the operation clock differs between the first mode (normal frame rate) and the second mode (low frame rate). That is, in the second mode, each of the first imaging unit and the second imaging unit captures an image at a low frame rate with a low operation clock signal, so that power consumption can be reduced. In addition, since the timing signal for imaging the frame is generated so that the exposure period is at least the same in both the first and second modes, an image having the same quality can be obtained in both modes.

  The capsule endoscope camera of the present invention has the same configuration as that of the imaging device.

  The imaging device and the capsule endoscope camera of the present invention can capture images of more directions. Further, power saving can be achieved. The first mode (normal frame rate) and the second mode (low frame rate) can be set without changing the frequency of the operation clock signal.

(Embodiment 1)
The imaging apparatus according to the first embodiment is a capsule-type endoscopic camera, and includes two first and second imaging units that capture images in different directions, so that images of more azimuths can be captured. . In addition, since the first imaging unit and the second imaging unit capture images in opposite directions, it is possible to efficiently capture images in more directions.

  FIG. 1 is a diagram illustrating a schematic configuration of an imaging apparatus 1 according to Embodiment 1 of the present invention. The image pickup apparatus shown in FIG. 1 includes a first image pickup means (first solid-state image pickup element 101, illumination light source 102, illumination light source 103, first lens 104) and second image pickup means (second solid-state image pickup element 201, illumination light source). 202, an illumination light source 203, a second lens 204), a system controller 10, a drive circuit 11, an analog circuit 12, a signal processing circuit 13, a transmission circuit 14, and a battery 15, and are accommodated in a capsule. This capsule is about the size of a human toe and is used as an endoscopic camera.

  The first imaging means includes an illumination light source 102, an illumination light source 103, a first lens 104, and a first solid-state image sensor 101 that captures an image using them.

  The second imaging means includes an illumination light source 202, an illumination light source 203, a second lens 204, and a second solid-state image sensor 201 that captures an image using them.

  The light-receiving surface of the first solid-state image sensor 101 and the light-receiving surface of the second solid-state image sensor 201 are directed in different directions (in the opposite direction in this embodiment). This is because images of many directions are taken by the two solid-state imaging devices. The first solid-state imaging device 101 has a first enable terminal that accepts the availability of operation, and the second solid-state imaging device 201 has a second enable terminal that accepts the availability of operation. The enable signals CE1 and CE2 to the first enable terminal and the second enable terminal are selectively validated by the system controller 10.

  Each illumination light source 102, 103, 202, 203 may be a white LED, for example. The illumination light sources 102 and 103 are turned on or off according to a lighting control signal LEN1 from the system controller 10. The illumination light sources 202 and 203 are turned on or off in accordance with the lighting control signal LEN2 from the system controller 10.

  The first and second solid-state imaging devices 101 and 201 are preferably MOS sensors in that a single power source may be used.

  The system controller 10, the drive circuit 11, the analog circuit 12, and the signal processing circuit 13 can be mounted as a one-chip DSP, and function as control means for selectively operating the first imaging means and the second imaging means. To do.

  The system controller 10 performs overall control of the imaging apparatus 1, selection control of the first solid-state imaging device 101 and the second solid-state imaging device 201, and lighting control of the illumination light sources 102, 103, 202, and 203.

  The drive circuit 11 outputs various drive signals CTL common to the first solid-state image sensor 101 and the second solid-state image sensor 201. Of the first solid-state image sensor 101 and the second solid-state image sensor 201, the one to which a valid enable signal is input performs an imaging operation. Further, the driving circuit 11 is a signal that is set semi-fixedly, and has a signal indicating the first mode (imaging at a normal frame rate) or the second mode (imaging at a low frame rate) as an operation mode. Is done. Semi-fixed means that, for example, it is set at the time of factory shipment, or is set electromagnetically or physically from the outside after factory shipment. The drive circuit 11 drives the first mode (imaging at a normal frame rate) or the second mode (imaging at a low frame rate) according to this signal.

  The analog circuit 12 and the signal processing circuit 13 function as an image processing unit that forms an image from an imaging signal from the first solid-state imaging device 101 or the second solid-state imaging device 201 selected by the control unit. The analog circuit 12 receives an analog imaging signal from the first solid-state imaging device 101 or the second solid-state imaging device 201 from the output OUT1 or OUT2, and performs A / D conversion. The signal processing circuit 13 forms an image from the digital image pickup signal after A / D conversion.

The transmission circuit 14 wirelessly transmits the image formed by the signal processing circuit 13.
The battery 15 supplies power to each unit in the imaging device 1.

  FIG. 2A is a diagram illustrating the lighting timing of the illumination light source. In FIG. 6A, “all pixel charge discharge” indicates the timing of resetting the charges of all the pixels. The “lighting control signal LEN1 / 2” indicates the lighting timing of the illumination light sources 102 and 103 (or 202 and 203). “Imaging element reading” indicates reading of an imaging signal for one frame by the first solid-state imaging element 101 (or the second solid-state imaging element 201). A period from “all pixel charge discharge” to “image sensor reading” indicates a driving period T for one frame. The lighting timing in FIG. 6A is from immediately after “all pixel charge discharge” within the driving period T to immediately before “image sensor reading”. That is, the illumination light source is turned on for a period from immediately after resetting all the pixels until immediately before the start of reading of the imaging signal. In the capsule endoscope camera, when the illumination light source is turned off, it can be considered that the incident light is zero. Therefore, it is not necessary to provide a mechanical shutter, and the lighting timing in FIG. .

  FIG. 2B is a diagram illustrating another lighting timing example of the illumination light source. The difference from FIG. 6B is that the lighting timing in FIG. 6B is not immediately after “all pixel charge discharge” but before “all pixel charge discharge” within the driving period T. Also at this lighting timing, exposure starts for each pixel immediately after the actual charge discharge. When the lighting of the “lighting control signal LEN1 / 2” is started, it may be somewhere after the image sensor reading is completed and before “all pixel charge discharge”. The restriction at the start of lighting will be relaxed.

  FIG. 3 is a diagram illustrating an example of the selection order of the first solid-state imaging device and the second solid-state imaging device. In this figure, “total charge discharge” and “lighting control signal” are the same as those in FIG. “Image sensor output” indicates the output of an image signal for one frame from the first solid-state image sensor 101 (or the second solid-state image sensor 201) to the analog circuit 12. The chip enable signal CE1 (or CE2) indicates a period during which the first solid-state image sensor 101 (or second solid-state image sensor 201) is selected, that is, a drive period T for one frame.

  In the example of the figure, the system controller 10 operates the first solid-state image sensor 101 and the second solid-state image sensor 201 alternately. When the first solid-state image sensor 101 and the second solid-state image sensor 201 are arranged symmetrically with respect to the position of the center of gravity of the capsule endoscope camera, the imaging direction by the first solid-state image sensor 101 and the second solid-state image sensor The balance with the imaging orientation by 201 can be made uniform.

  FIG. 4 is a diagram illustrating an example of another selection order of the first solid-state imaging device and the second solid-state imaging device. In the example of the figure, the system controller 10 selects the first solid-state image sensor 101 and the second solid-state image sensor 201 at a ratio of 1: 2. When the first solid-state imaging device 101 and the second solid-state imaging device 201 are asymmetrically arranged with respect to the center of gravity of the capsule endoscope camera, the imaging direction by the first solid-state imaging device 101 and the second solid-state imaging device The balance with the imaging orientation by 201 can be equalized or adjusted.

  FIG. 5 is a diagram illustrating a selection control operation of the first solid-state image sensor 101 and the second solid-state image sensor 201 by the system controller 10. In the figure, “chip enable signal”, “total charge discharge”, “lighting control signal”, “image sensor read”, and “image sensor output” are the same as those in FIGS. In the configuration of FIG. 1, various control signals CTL from the drive circuit 11 are commonly supplied, but chip enable signals CE1 and CE2 from the system controller 10 are supplied to the first solid-state image sensor 101 and the second solid-state image sensor 201. It is supplied separately. That is, the various control signals CTL are also supplied to the solid-state imaging device to which no valid chip enable signal is input (broken line portion in the figure). The various control signals CTL in the broken line portion are ignored by the solid-state imaging device because no valid chip enable signal is input, and do not affect the internal operation. Thus, the system controller 10 can perform selection control of the first solid-state image sensor 101 and the second solid-state image sensor 201 with a simple configuration.

  FIG. 6 is a diagram illustrating operation timings in (a) the first mode (normal frame rate) and (b) the second mode (low frame rate). In FIGS. 5A and 5B, the operation lock signal supplied to the first solid-state image sensor 101 and the second solid-state image sensor 201 is inputted with a clock signal (normal clock signal) having the same frequency.

  As shown in FIG. 6A, in the first mode, the drive circuit 11 has a first idle period between frame imaging periods (frame driving periods) in the first solid-state imaging element 101 and the second solid-state imaging element 201. Is inserted to drive imaging at a normal frame rate. The first idle period may be from 0 clock cycle to several clock cycles.

  Also, as shown in FIG. 5B, in the second mode, an operation clock signal having the same frequency as that in the first mode is supplied to the first solid-state image sensor 101 and the second solid-state image sensor 201, and the drive circuit 11 A second idle period longer than the first idle period is inserted between the frame imaging periods of the first solid-state image sensor and the second solid-state image sensor. As long as the second idle period is longer than the first idle period, it may be about a clock cycle corresponding to n times the frame imaging period. As a result, it is possible to perform imaging by thinning out the frame substantially, and it is possible to extend the life of the battery.

  As described above, the imaging device and the capsule endoscope camera according to the present embodiment can capture images of more directions. Further, power saving can be achieved. The first mode (normal frame rate) and the second mode (low frame rate) can be selected without changing the frequency of the operation clock signal.

(Embodiment 2)
In the first embodiment, an example in which the same operation clock signal is used in the first mode (normal frame rate) and the second mode (low frame rate) has been described. However, in the second embodiment, in the second mode, An example in which an operation clock signal having a frequency lower than that in one mode is used will be described. According to this, further power saving can be achieved in the second mode.

  The schematic configuration of the imaging apparatus in the present embodiment is substantially the same as that in FIG. 1, but instead of the first solid-state imaging element 101 and the second solid-state imaging element 201, the first solid-state imaging element 101a and the second solid-state imaging element 201a. And the point that the drive circuit 11 does not insert an idle period in the second mode (low frame rate). Hereinafter, the description of the same points will be omitted, and different points will be mainly described.

  FIG. 7 is a block diagram showing a configuration of the first solid-state imaging element 101a in the present embodiment. As shown in the figure, the first solid-state imaging device 101a includes an imaging area 110 having a matrix pixel array, a vertical shift register 111 that scans the imaging area 110 in rows, and a horizontal that scans the imaging area 110 in columns. A shift register 112, a high-speed timing generation unit 113, a low-speed timing generation unit 114, and a selector 115 are provided.

  The high-speed timing generation unit 113 functions as first timing signal generation means for generating a frame imaging timing signal based on the first operation clock signal in the first mode.

  The low speed timing generation unit 114 generates a second timing signal for imaging that has at least the same exposure period as the first timing signal generation unit, based on the second operation clock signal having a frequency lower than that of the first operation clock signal. It functions as a timing signal generation means.

  The selector 115 selects the imaging timing signal from the low-speed timing generation unit 114 according to a signal (high-speed / low-speed signal) indicating whether the operation clock signal is the first operation clock signal or the second operation clock signal. One of the imaging timing signals from the selector 115 is selected and supplied to the vertical shift register 111 and the horizontal shift register 112.

The second solid-state imaging device 201a has the same configuration as that in FIG.
FIG. 8 is a diagram showing operation timings in (a) the first mode (normal frame rate) and (b) the second mode (low frame rate). In FIG. 9A, the first operation clock (high-speed clock) is supplied to the first solid-state image sensor 101 and the second solid-state image sensor 201 in FIG.

  As shown in FIG. 6A, the high-speed timing generation unit 113 generates various timing signals for controlling imaging of one frame over the driving period T when a high-speed clock is input. On the other hand, as shown in FIG. 5B, when the low-speed clock is input, the low-speed timing generation unit 114 has various control signals for controlling imaging of one frame at a timing at which the exposure period is at least the same as that for high-speed. The “image sensor reading” period is generated and changes in accordance with the operation clock. In FIGS. 4A and 4B, the period of one frame and the driving period are different, but the “all pixel charge discharging” period and the exposure period are the same.

  As described above, according to the second embodiment, the frequency of the operation clock differs between the first mode (normal frame rate) and the second mode (low frame rate). That is, in the second mode, each of the first imaging unit and the second imaging unit captures an image at a low frame rate with a low operation clock signal, so that further reduction in power consumption can be achieved. In addition, since the frame timing signal is generated at least at the same timing of the exposure period, the same quality image can be obtained in either mode.

  In each of the above embodiments, an example in which a MOS solid-state image sensor is provided has been described. However, a configuration in which a CCD solid-state image sensor is provided instead of a MOS type may be used.

  Moreover, you may make it become the same length only in the lighting period of an illumination light source in Fig.8 (a) and FIG.8 (b).

  Further, a weight that sets the center of gravity of the capsule endoscope camera at the center of the capsule may be provided. In this way, the shooting directions of the first solid-state image sensor 101 and the second solid-state image sensor 201 can be equalized. Conversely, a weight for biasing the center of gravity of the capsule endoscope camera from the center of the capsule may be provided. In this way, the shooting directions of the first solid-state image sensor 101 and the second solid-state image sensor 201 can be biased.

  In addition, although the example which image | photographs both directions of a capsule longitudinal direction was shown, you may make it image | photograph 2 directions orthogonal to a capsule longitudinal direction.

  In each of the above embodiments, an example in which two sets of imaging means (solid-state imaging device, lens, and illumination light source) are provided has been described, but three or more sets may be provided. In that case, if the shooting directions of the plurality of image pickup means are set to be symmetric with respect to the capsule, the shooting directions of the respective solid-state image sensors can be equalized.

    The present invention can be applied to an imaging apparatus, and in particular, can be applied to a capsule endoscope camera.

It is a figure which shows schematic structure of the imaging device in Embodiment 1 of this invention. It is a figure which shows the read-out timing of an image pick-up element, and the lighting timing of an illumination light source. It is a figure which shows the selection order of a 1st solid-state image sensor and a 2nd solid-state image sensor. It is a figure which shows the other selection order of a 1st solid-state image sensor and a 2nd solid-state image sensor. It is a figure which shows selection control operation | movement of a 1st solid-state image sensor and a 2nd solid-state image sensor. It is a figure which shows a normal frame rate and a low frame rate. It is a figure which shows schematic structure of the imaging device in Embodiment 2 of this invention. It is a figure which shows a normal frame rate and a low frame rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging device 10 System controller 11 Drive circuit 12 Analog circuit 13 Signal processing circuit 14 Transmission circuit 15 Battery 101 1st solid-state image sensor 102, 103 Illumination light source 104 1st lens 110 Imaging area 111 Vertical shift register 112 Horizontal shift register 113 High speed Timing generator 114 Low-speed timing generator 115 Selector 201 Second solid-state imaging device 202, 203 Illumination light source 204 Second lens CTL control signal CE1, CE2 Enable signal LEN1, LEN2 Lighting signal OUT1, OUT2 Output signal

Claims (9)

A first imaging means including a first illumination light source, a first lens, and a first solid-state imaging device that images using the first illumination light source and the first lens;
A second illumination light source, a second lens, and a second solid-state imaging device that captures an image using the second illumination light source and the second lens, and that captures a different direction from the first imaging means. Two imaging means;
Control means for selectively operating the first imaging means and the second imaging means;
Image processing means for forming an image from an imaging signal from the imaging means selected by the control means;
Transmitting means for wirelessly transmitting an image formed by the image processing means;
An imaging apparatus comprising: The imaging apparatus, wherein the first imaging means and the second imaging means image in opposite directions. The first solid-state imaging device has a first enable terminal for accepting operation availability,
The second solid-state imaging device has a second enable terminal for accepting operation availability,
The imaging apparatus according to claim 1, wherein the control unit selectively enables each enable signal to the first enable terminal and the second enable terminal. The imaging apparatus according to claim 1, wherein the control unit operates the first imaging unit and the second imaging unit alternately. The imaging apparatus according to claim 1, wherein the control unit operates to make the number of selections of the first imaging unit and the second imaging unit non-equal. The imaging apparatus according to claim 3, wherein the control unit supplies a driving signal common to the first solid-state imaging device and the second solid-state imaging device. The control means includes
A first mode and a second mode are selectively operated with respect to the first solid-state image sensor and the second solid-state image sensor;
In the first mode, a first idle period is inserted between frame imaging periods in the first solid-state image sensor and the second solid-state image sensor,
In the second mode, an operation clock signal having the same frequency as that of the first mode is supplied to the first solid-state imaging device and the second solid-state imaging device, and the frame imaging period of the first solid-state imaging device and the second solid-state imaging device is The imaging apparatus according to claim 1, wherein a second idle period longer than the first idle period is inserted between intervals. Each of the first solid-state image sensor and the second solid-state image sensor is
First timing signal generating means for generating an imaging timing signal based on the first operation clock signal;
Second timing signal generation means for generating an imaging timing signal having at least the same exposure period as the first timing signal generation means based on a second operation clock signal having a frequency lower than that of the first operation clock signal;
In response to a signal indicating whether the operation clock signal is the first operation clock signal or the second operation clock signal, the imaging timing signal from the first timing signal generation unit and the imaging from the second timing signal generation unit The imaging apparatus according to claim 1, further comprising selection means for selecting one of the timing signals for use. A capsule-type endoscopic camera comprising the imaging device according to claim 1.

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