JP4589706B2 - Endoscope light source device and electronic endoscope device - Google Patents

Description

  The present invention relates to a light source device and an electronic endoscope device, and more particularly to a light source device that can be used in an electronic endoscope device and an electronic endoscope device having an electronic shutter function.

  An electronic endoscope apparatus is generally composed of a processor including a light source for illuminating a body tissue that is a subject, and a video scope including an image sensor. Illumination light from the light source is applied to the subject from the tip of the video scope through a light guide inserted into the video scope. Then, an image signal obtained by the image sensor is transmitted to the processor, and a predetermined process is performed on the image signal in the processor, whereby the subject image is displayed on the monitor.

Further, when the electronic endoscope apparatus has an electronic shutter function, it is known to capture a still image using a high-speed shutter in the electronic shutter function. In general, when the electronic shutter function is used, when the shutter speed is increased to obtain a still image in which blurring is suppressed, the dimming aperture is opened to increase the amount of illumination light (see, for example, Patent Document 1). .
JP 2003-305005 A (FIGS. 5 and 6)

  When recording a still image using a high-speed shutter in the electronic shutter function, sufficient charges are accumulated within a short exposure time corresponding to the high-speed shutter in order to obtain a still image having the same brightness (luminance) as that of a moving image. It is necessary to At this time, if the amount of illumination light increases more than necessary, there is a high possibility that halation will occur, and there may be a high temperature at the tip of the video scope that irradiates the subject with illumination light.

  The present invention realizes an endoscope light source device and an electronic endoscope device that can secure sufficient luminance at the time of recording a still image and prevent the occurrence of halation by controlling the amount of illumination light. For the purpose.

  The light source device of the present invention is used in an electronic endoscope device capable of recording a still image with a high-speed shutter in an electronic shutter function. The light source device includes a light source that emits illumination light for illuminating a subject, a light amount adjusting unit that adjusts the light amount of the illumination light, and a freeze light amount that is a light amount of illumination light that should be irradiated to the subject when recording a still image. Light amount storage means for storing the light amount for adjusting the amount of illumination light. The light amount adjusting means preferably uses the light amount of illumination light as a freeze light amount when recording a still image.

  In addition, the light source device preferably further includes a light amount detection unit that detects a light amount of the illumination light applied to the subject. In this case, the light amount adjustment unit is detected by the light amount detection unit for recording a still image. The amount of illumination light is increased by the difference between the amount of illumination light and the amount of freeze light during the observation of a moving image.

  The light amount detection means preferably includes an optical sensor that receives a part of the illumination light, and more preferably has a spectroscopic means for causing a part of the illumination light to enter the optical sensor. Further, it is desirable that the light amount adjusting means adjusts the light intensity of the illumination light by controlling the output of the light source.

  The electronic endoscope apparatus of the present invention is capable of recording a still image with a high-speed shutter in the electronic shutter function, and a light source that emits illumination light for illuminating a subject, and a light amount adjustment that adjusts the light amount of the illumination light And a light amount storage means for storing a freeze light amount, which is a light amount of illumination light to be irradiated on the subject at the time of recording a still image, in order to adjust the light amount of the illumination light. And it is preferable that a light quantity adjustment means adjusts a light quantity so that the light quantity of illumination light may become a freeze light quantity at the time of the recording of a still image.

  The electronic endoscope apparatus further includes, for example, a light amount detection unit that detects the amount of illumination light irradiated to the subject. In this case, the light amount adjustment unit is detected by the light amount detection unit for recording a still image. The amount of illumination light is increased by the difference between the amount of illumination light and the amount of freeze light during observation of the moving image.

  Further, the electronic endoscope apparatus is based on, for example, an imaging element that receives reflected light of illumination light to generate an image signal, a luminance detection unit that detects the luminance of the subject based on the image signal, and the luminance of the subject. A light amount calculating means for calculating the light amount of the illumination light applied to the subject. In this case, the light amount adjusting means is for observing the moving image calculated by the light amount calculating means for recording a still image. The amount of illumination light is increased by the difference between the amount of illumination light and the amount of freeze light.

  According to the present invention, there is provided an endoscope light source device and an electronic endoscope device capable of ensuring sufficient luminance at the time of recording a still image and preventing occurrence of halation by controlling the amount of illumination light. realizable.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 is a block diagram of an electronic endoscope apparatus.

  The electronic endoscope apparatus 10 includes a video scope 20 used for imaging in a body cavity of a patient, and a processor 30 that supplies illumination light to the video scope 20 and processes an image signal transmitted from the video scope 20. Prepare. The video scope 20 is detachably connected to the processor 30, and a monitor 80 is connected to the processor 30.

  The processor 30 is provided with a light source device including a light source 32 incorporating a xenon lamp (not shown) for irradiating illumination light, a light source power supply 34 for supplying a current to the light source 32, and the like. The light source power supply 34 supplies a current to the light source 32 by operating a light source lighting switch (not shown) and supplying power from the AC input terminal 36. Thereby, the light source 32 emits illumination light for illuminating the subject. Illumination light emitted from the light source 32 passes through a light guide lens (not shown), a mesh diaphragm 38 driven by a mesh diaphragm drive motor 46, and the half mirror 35, and enters the incident end 12A of the light guide 12. . The light guide 12 transmits illumination light incident from the incident end 12A to the distal end portion of the video scope 20 having the observation site, and the illumination light passing through the light guide 12 is emitted from the light guide emission end 12B. A part of the illumination light is reflected by the half mirror 35 and sent to the optical sensor 37. The optical sensor 37 that has received a part of the illumination light detects the light amount of the illumination light incident on the light guide incident end 12 </ b> A and transmits the light amount data to the control circuit 50. In the light source device, a light source fan 42 for cooling the light source 32 and a power source fan 44 for cooling the light source power source 34 are provided.

  Illumination light reflected from the observation site, which is a subject, reaches the CCD 22 through an objective lens (not shown) and a color filter (not shown). Then, electric charges generated by photoelectric conversion for forming an image signal of the subject image corresponding to the color passing through the color filter are accumulated on the light receiving surface of the CCD 22. Here, the NTSC system is applied as the color television system, and the image signals generated in the CCD 22 are sequentially read out every field period, that is, every 1/60 second interval, and sent to the initial signal processing circuit 24. . Note that since an electronic shutter is used for recording a still image, a part of the electric charge accumulated in the CCD 22 is swept away.

  In the video scope 20, a scope control unit 26 that controls the entire video scope 20 and an EEPROM 28 in which data related to characteristics and signal processing of the video scope 20 are stored in advance are provided. The scope control unit 26 sends a control signal to the initial signal processing circuit 24 and reads data from the EEPROM 28 as appropriate.

  The initial signal processing circuit 24 performs amplification processing on the read image signal, and further converts the analog image signal into a digital image signal. Various processes such as white balance adjustment are performed on the digital image signal to generate a luminance signal and a color difference signal. The luminance signal and the color difference signal are sent to the processor signal processing circuit 48 of the processor 30, converted into a video signal such as an NTSC signal, and output to the monitor 80. As a result, the subject image is displayed on the monitor 80. The luminance signal generated by the initial signal processing circuit 24 is also transmitted to the scope control unit 26, and the scope control unit 26 sets the shutter speed of the electronic shutter to an appropriate value based on the luminance signal.

  The video scope 20 is provided with a freeze button 25. When the user presses the freeze button 25, a trigger signal for recording a still image is transmitted to the control circuit 50 of the processor 30 via the scope control unit 26. The control circuit 50 is powered by the system power supply 52 and controls the entire processor 30 including the light source device. When the control circuit 50 receives the trigger signal, the control circuit 50 transmits a signal for controlling irradiation of illumination light to the light source power supply 34 or the screen drive motor 46. Based on the signal from the control circuit 50, the light source power supply 34 adjusts the light intensity of the illumination light emitted from the light source 32, and the screen driving motor 46 and the screen 38 pass through the screen 38. The amount of illumination light to be adjusted can be adjusted.

  In recording a still image using the electronic shutter function, the control circuit 50 increases the amount of illumination light in comparison with a normal moving image observation in order to obtain a blur-free image by increasing the shutter speed. The control circuit 50 stores in advance data on the amount of freeze light that is the amount of illumination light to be irradiated on the subject when recording a still image. The control circuit 50 determines that the amount of illumination light is frozen when recording a still image. The light source power supply 34 is controlled so that Here, when the control circuit 50 receives a trigger signal for recording a still image, the light source device emits light amount data of illumination light emitted when the trigger signal is received in order to observe a moving image. 37, and the difference between the amount of illumination light and the amount of freeze light is calculated. Then, in order to increase the light intensity of the illumination light emitted from the light source 32 by an amount corresponding to the calculated light amount difference, the light source power supply 34 is instructed to increase the amount of current supplied to the light source 32. Send an instruction signal.

  In this way, when recording a still image, illumination light is irradiated for a predetermined amount of freeze light, so that halation due to an increase in the amount of light more than necessary and high temperature at the light guide emission end 12B are prevented. . In addition, the control circuit 50 does not calculate the amount of illumination light from the light source 32 and the ratio of the illumination light that passes through the mesh diaphragm 38, but the illumination light that is actually irradiated toward the subject. Since the light quantity difference is calculated based on the light quantity, accurate light quantity control is possible.

  FIG. 2 is a diagram schematically showing the arrangement of the light source device and the like in the processor 30 as viewed from above. FIG. 3 is a front view of the processor 30, and FIG. 4 is a rear view of the processor 30.

  The light source device is provided on the left side in front of the processor 30. On the right side of the front of the processor 30, the signal is sent via a control board 60 having a processor signal processing circuit 48 and a control circuit 50, an RGB connector 64 and a Y / C connector 66 (see FIG. 4) described later. And a rear panel substrate 62 having a circuit for processing the signal to be processed.

  On the front surface 30L of the processor 30, an operation panel 68 used by a user for brightness adjustment, noise reduction, etc., a processor side end 12E of the light guide 12, and a scope insertion port for inserting an electric terminal of the video scope 20 70 is provided (see FIG. 3). When the user operates the operation panel 68, a predetermined instruction signal corresponding to the operation is transmitted to the control circuit 50, and processing such as brightness adjustment and noise reduction is performed. On the other hand, an RGB connector 64, a Y / C connector 66, and an AC input terminal 36 are provided on the back surface 30R of the processor 30 (see FIG. 4).

  FIG. 5 is a diagram schematically showing the arrangement of members that control illumination light irradiation in the light source device. FIG. 6 is a diagram illustrating a net aperture 38 having a plurality of openings, and FIG. 7 is a diagram illustrating a ratio of the amount of illumination light that each aperture of the net aperture 38 passes.

  The light guide lens 54 is provided to guide the illumination light emitted from the xenon lamp 33 in the light source 32 to the light guide incident end 12A, and the optical axis of the light guide lens 54 and the optical path L of the illumination light. Match. Further, the half mirror 35 disposed on the optical path L of the illumination light changes a part of the optical path of the illumination light in a direction perpendicular to the optical path L and sends it to the optical sensor 37. The mesh diaphragm 38 is a disk-shaped member, and is rotated by a mesh diaphragm drive motor 46 around a rotation axis A parallel to the optical path of the illumination light. The mesh diaphragm 38 is provided with first to eleventh openings 38A to 38K for allowing the illumination light to pass along the direction parallel to the optical path L of the illumination light, and a positioning hole 74 (see FIG. 6). . A diaphragm position sensor 72 arranged so as to sandwich the mesh diaphragm 38 near the outer periphery detects the position of the positioning hole 74, thereby detecting the rotational position of the mesh diaphragm 38.

  The ratio of the amount of illumination light that the first to eleventh openings 38A to 38A-K pass with respect to the amount of incident illumination light (hereinafter referred to as aperture ratio) are all different (see FIG. 7). 46 rotates the screen aperture 38 based on an instruction from the control circuit 50 so that an aperture having an appropriate aperture ratio is at a position where illumination light passes (hereinafter referred to as a passing position). When the light source device is activated, the screen aperture 38 is rotated so that the third opening 38C is always in the passing position based on the position of the positioning hole 74, and the third opening 38C is normally used. When the aperture to be used is changed, the aperture stop driving motor 46 that has received the instruction signal from the control circuit 50 rotates the aperture stop 38 by a predetermined amount, so that the aperture having an appropriate aperture ratio is brought to the passing position. Be placed.

  FIG. 8 is a flowchart showing a subject observation routine by the electronic endoscope apparatus 10.

  When the electronic endoscope apparatus 10 is turned on, the subject observation routine starts. In step S1, the light source device is activated and the position of the screen aperture 38 is initialized. That is, the third opening 38C used for normal moving image observation is placed at the passing position, and the process proceeds to step S2. In step S <b> 2, it is determined whether the video scope 20 is connected to the processor 30. If the video scope 20 is connected to the processor 30, the process proceeds to step S3, and if not connected, step S2 is repeated.

  In step S3, it is determined whether or not the light source lighting switch is on. If the light source lighting switch is on, the process proceeds to step S4. If the light source lighting switch is off, step S3 is repeated. In step S4, the control circuit 50 transmits a light source ON signal for turning on the light source to the light source power supply 34, and the process proceeds to step S5. In step S5, the light source power supply 34 transmits a lighting signal indicating that the light source 32 has been lit to the control circuit 50, and the process proceeds to step S6. In step S6, exposure control is performed. That is, the light emission intensity of the light source 32 and the aperture ratio of the screen aperture 38 are set to predetermined values, and the scope control unit 26 determines the shutter speed of the electronic shutter based on the luminance signal indicating the luminance of the subject, and the step Proceed to S7.

  In step S7, it is determined whether or not the user has pressed the freeze button 25 to give a freeze request, that is, an instruction to record a still image. If the user has requested a freeze, the process proceeds to step S8. If the user has not requested a freeze, the process proceeds to step S9. In step S8, as will be described later, a still image is recorded by a high-speed shutter having an electronic shutter function.

  In step S9, it is determined whether or not the user has operated the operation panel 68. If the user has operated the operation panel 68, the process proceeds to step S10. If not, the process proceeds to step S11. In step S10, based on the instruction signal from the operation panel 68, the control circuit 50 or the like performs a predetermined calculation process, and proceeds to step S11. In step S11, it is determined whether or not the user has operated the light source lighting switch so as to be turned on again. When the user is operated so as to be turned on again, the process proceeds to step S12 so as to be turned on again. If not operated, the process returns to step S7. In step S12, the control circuit 50 transmits a light source off signal for turning off the light source to the light source power source 34, and the process returns to step S3.

  FIG. 9 is a flowchart showing a light amount control routine during still image recording. FIG. 10 is a timing chart showing light amount control during still image recording.

The light amount control routine is started by a user's freeze request (see steps S7 and S8 in FIG. 8). In step S13, the user presses the freeze button 25, a trigger signal TS for recording a still image is transmitted to the control circuit 50, and the process proceeds to step S14. In step S14, the control circuit 50 causes the light sensor 37 to transmit data on the amount of illumination light emitted by the light source device when the trigger signal TS is received, and the amount of light that is the difference between the amount of illumination light and the amount of freeze light. The difference is calculated and the process proceeds to step S15. In step S15, the control circuit 50 sends an instruction signal to the light source power supply 34 so as to increase the light intensity of the illumination light emitted from the light source 32 in order to increase the light amount of the illumination light by the light amount difference. Proceed to S16. In step S16, the amount of current supplied from the light source power supply 34 to the light source 32 is increased by a predetermined amount, for example, from 15 (A) to 20 (A) when observing a moving image (time T _{1 in} FIG. 10). Proceed to step S17. As a result, the light intensity of the illumination light emitted from the light source 32 increases, and the amount of illumination light applied to the subject becomes the freeze light amount.

In step S17, based on the luminance of the subject, it is determined whether or not the scope control unit 26 has set the shutter speed of the electronic shutter to an appropriate value. Here, since the amount of light applied to the subject increases to be a freeze amount compared to the time of moving image observation, the scope control unit 26 sets the shutter speed of the electronic shutter to the value at the time of moving image observation ( For example, the speed is increased from 1/250 seconds to a value (for example, 1/1000 second) suitable for the luminance of the subject irradiated with illumination light corresponding to the amount of freeze light (time T _{3 in} FIG. 10). If it is determined in step S17 that the change of the shutter speed has been completed, the process proceeds to step S18. If it is determined that the change of the shutter speed has not been completed, step S17 is repeated.

In step S18, the image data of the still image is captured, that is, the luminance signal and the color difference signal based on the image signal of the subject image generated in the CCD 22 are transmitted to the processor signal processing circuit 48. The processor signal processing circuit 48 transmits a signal notifying the end of image data capture to the control circuit 50, and proceeds to step S19. In step S <b> 19, the control circuit 50 that has received the signal that informs the end of the image data capture transmits an instruction signal for reducing the amount of current supplied to the light source 32 to the light source power supply 34. As a result, the amount of current to the light source 32 returns again to the value at the time of normal moving image observation (time T _{3 in} FIG. 10), and the light amount control routine ends. As described above, when a still image is recorded, the light intensity of the illumination light emitted from the light source 32 returns to the value at the time of normal subject observation, so the scope control unit 26 sets the shutter speed of the electronic shutter to a moving image. It returns to the value at the time of image observation (time T _{4 in} FIG. 10).

  As described above, according to the present embodiment, the illumination light is irradiated for the amount of freeze light that is at least necessary for recording a still image, so that it is possible to record a clear still image without blurring. The occurrence of halation due to an increase in the amount of light more than necessary and the high temperature of the tip of the video scope 20 are prevented.

  Next, the electronic endoscope apparatus 10 according to the second embodiment will be described. In the electronic endoscope apparatus 10 according to the second embodiment, the half mirror 35 and the optical sensor 37 are not provided, and a light amount calculation circuit (not shown) included in the control circuit 50 is based on the luminance signal. The only difference from the first embodiment is that the amount of illumination light actually irradiated on the subject is calculated. That is, the control circuit 50 calculates the difference between the actual illumination light amount calculated by the light amount calculation circuit and the freeze light amount, and controls the light source power supply 34 to increase the light amount by an amount corresponding to the light amount difference. To do. The light source power supply 34 increases the amount of current supplied to the light source 32 by a predetermined amount, so that the illumination light is irradiated by a predetermined amount of freeze light.

  As described above, according to the present embodiment, sufficient luminance is ensured when recording a still image without providing the optical sensor 37 or the like that detects the actual amount of illumination light emitted toward the subject. However, it is possible to prevent the amount of light from increasing more than necessary.

  The control circuit 50 may control the light amount of the illumination light so as to be the freeze light amount only when recording a still image without controlling the light amount of the illumination light when observing the moving image. In addition, when recording a still image by the electronic shutter function, instead of adjusting the light intensity of the illumination light from the light source 32, the light quantity of the illumination light passing through the mesh diaphragm 38 is adjusted to reduce the illumination light quantity to the freeze light quantity. It may be increased. In this case, instead of transmitting a signal for adjusting the light intensity of the illumination light to the light source power source 34, a signal for selecting an aperture having a predetermined aperture ratio is transmitted to the screen aperture driving motor 46. Further, both the light intensity of the illumination light emitted from the light source 32 and the amount of illumination light passing through the mesh diaphragm 38 may be adjusted simultaneously.

  The type of the light source 32 is not limited to the first and second embodiments, and a halogen lamp or the like may be used. The diaphragm is not limited to the mesh diaphragm 38, and an iris diaphragm may be used. Further, the amount of current supplied to the light source 32, the aperture ratio of the screen aperture 38, the shutter speed of the electronic shutter, and the like are not limited to the present embodiment, and are adjusted according to the subject observation situation and the like.

It is a block diagram of the electronic endoscope apparatus in a 1st embodiment. It is a figure which shows roughly arrangement | positioning of a light source device etc. in a processor seeing from the top. It is a front view of a processor. It is a rear view of a processor. It is a figure which shows roughly arrangement | positioning of the member which controls irradiation of illumination light in a light source device. It is a figure which shows the net stop which has several opening. It is a figure which shows the aperture ratio of the opening of a net aperture. 3 is a flowchart showing a subject observation routine. It is a flowchart which shows the light quantity control routine at the time of a still image recording. It is a timing chart which shows light quantity control at the time of still image recording.

Explanation of symbols

10 Electronic Endoscope 20 Videoscope 22 CCD (Imaging Device)
24 Initial signal processing circuit (luminance detection means)
30 processor 32 light source 34 power source for light source (light quantity adjusting means / power source)
35 Half mirror (spectral means)
37 Optical sensor (light quantity detection means)
50 Control circuit (light quantity adjusting means / light quantity storing means / light quantity calculating means)

Claims (3)

A light source device used in an electronic endoscope apparatus capable of recording a still image with a high-speed shutter in an electronic shutter function,
A light source that emits illumination light for illuminating a subject;
A light amount adjusting means for adjusting a light amount of the illumination light;
A light amount storage means for storing a freeze light amount, which is a light amount of the illumination light to be irradiated to a subject when recording a still image, in order to adjust the light amount of the illumination light ;
A light amount detecting means for detecting a light amount of the illumination light irradiated to the subject ,
The light amount adjusting means sets the light amount of the illumination light as the freeze light amount when recording a still image,
The light amount adjusting unit increases the light amount of the illumination light by a difference between the light amount of the illumination light and the freeze light amount at the time of observing the moving image detected by the light amount detection unit for recording a still image,
The light amount detecting means is disposed on the optical path of the illumination light, and includes a half mirror as a spectroscopic means for reflecting a part of the illumination light to enter the light sensor, and the light sensor is included in the light sensor. A light source device that guides the remaining incident light to a light guide incident end of an electronic endoscope scope . The light source device according to claim 1 , wherein the light amount adjusting unit adjusts the light intensity of the illumination light by controlling an output of the light source. An electronic endoscope apparatus capable of recording a still image with a high-speed shutter in an electronic shutter function,
A light source that emits illumination light for illuminating a subject;
A light amount adjusting means for adjusting a light amount of the illumination light;
A light amount storage means for storing a freeze light amount, which is a light amount of the illumination light to be irradiated to a subject at the time of recording a still image, in order to adjust the light amount of the illumination light;
A light amount detecting means for detecting a light amount of the illumination light irradiated to the subject,
The light amount adjusting means sets the light amount of the illumination light as the freeze light amount when recording a still image,
The light amount adjusting unit increases the light amount of the illumination light by a difference between the light amount of the illumination light and the freeze light amount at the time of observing the moving image detected by the light amount detection unit for recording a still image,
The light amount detecting means is disposed on an optical path of the illumination light, and includes a half mirror as a spectroscopic means for reflecting a part of the illumination light to be incident on an optical sensor. An electronic endoscope apparatus characterized in that the remaining incident light is guided to a light guide incident end of an electronic endoscope scope.

Images