JPWO2019221306A1 - Endoscope system - Google Patents

Abstract

The endoscope system according to the present invention includes an illumination unit that sequentially switches a plurality of illumination lights including different wavelength bands to irradiate the subject, and a plurality of pixels that photoelectrically convert the return light from the subject to generate an image signal. Using an endoscope having an imaging unit that reads out an image signal generated by a pixel in synchronization with the irradiation timing of the illumination unit, and a plurality of image signals generated based on the return light of each illumination light. Imaging condition switching that switches the imaging unit between the normal mode and the high-speed mode, which has a higher imaging frame rate than the normal mode, based on the identification information of the image processing unit that performs simultaneous processing and the endoscope. It is provided with a unit and a binning control unit that causes the imaging unit to execute reading processing by increasing the number of pixels as a reading unit as compared with the normal mode when the high-speed mode is set.

Description

The present invention relates to an endoscope system including an endoscope.

Conventionally, in the medical field, an endoscopic system has been used for observing the inside of a subject. In general, an endoscope inserts a flexible insertion portion having an elongated shape into a subject such as a patient, illuminates the illumination light supplied by a light source device from the tip of the insertion portion, and reflects the illumination light. An image of the inside of the body is captured by receiving light at the imaging unit at the tip of the insertion unit. The internal image captured by the imaging unit of the endoscope is displayed on the display of the endoscope system after being subjected to predetermined image processing in the processing device of the endoscope system. A user such as a doctor observes the organ of the subject based on the internal image displayed on the display.

As one of the methods for acquiring a color image, a surface sequential method is known (see, for example, Patent Documents 1 and 2). In the surface sequential method, a color image is acquired by sequentially switching illumination lights of a plurality of wavelength bands different from each other and irradiating the subject, and imaging the subject in synchronization with the irradiation of the illumination light.

By the way, in the case of acquiring an image of a subject by a surface-sequential method, when the subject is moving at a high speed, a color shift occurs due to a shift in the position of the subject each time the illumination light is applied. In Patent Documents 1 and 2, color shift is prevented by increasing the imaging frame rate. For example, in Patent Document 2, depending on the observation site, the light emission mode is switched between a light emission mode that emits illumination light at a cycle of 1/60 seconds and a light emission mode that emits illumination light at a cycle of 1/120 seconds. ing.

Japanese Unexamined Patent Publication No. 2016-46780 Japanese Unexamined Patent Publication No. 2007-29746

However, when the imaging frame rate is increased, there is a problem that the brightness of the image is lowered.

The present invention has been made in view of the above, and an object of the present invention is to provide an endoscopic system capable of acquiring an image in which a decrease in brightness is suppressed even if an imaging frame rate is increased.

In order to solve the above-mentioned problems and achieve the object, the endoscopic system according to the present invention includes an illumination unit that sequentially switches a plurality of illumination lights including different wavelength bands to irradiate the subject, and an illumination unit from the subject. An endoscope having a plurality of pixels that photoelectrically convert return light to generate an image signal and having an imaging unit that reads out the image signal generated by the pixels in synchronization with the irradiation timing of the illumination unit, and the above. An image processing unit that performs simultaneous processing on the image signals read by the imaging unit using a plurality of the image signals generated based on return light of illumination light having different wavelength bands, and the endoscope. Imaging condition switching to switch between a normal mode in which the imaging unit is made to image at a preset imaging frame rate and a high-speed mode in which the imaging frame rate is higher than the normal mode based on the identification information of It is characterized by including a unit and a binning control unit that causes the imaging unit to execute a reading process by increasing the number of pixels as a reading unit as compared with the normal mode when the high-speed mode is set. ..

Further, in the endoscopic system according to the present invention, in the above invention, the illumination unit is a red semiconductor light emitting element that emits red illumination light in the red wavelength band and green that emits green illumination light in the green wavelength band. From the semiconductor light emitting element, the blue semiconductor light emitting element that emits blue illumination light in the blue wavelength band, the red semiconductor light emitting element, the green semiconductor light emitting element, and the blue semiconductor light emitting element according to the setting of the imaging frame rate. The illumination control unit has an illumination control unit that switches the emission of the illumination light, and when the illumination control unit is set to the high-speed mode, the illumination light is lit in the order of the red illumination light, the green illumination light, and the like. The blue illumination light and the green illumination light are used.

Further, in the above invention, the endoscope system according to the present invention further includes an enlargement processing unit that performs electronic enlargement processing on the image signal, and in the enlargement processing unit, the binning control unit is used as the image pickup unit. It is characterized in that the electron enlargement ratio is switched according to the number of pixels as the read unit executed.

Further, in the endoscope system according to the present invention, in the above invention, the imaging condition switching unit switches the imaging frame rate and / or the number of pixels as the reading unit based on the parameters related to the image signal. It is characterized by.

According to the present invention, there is an effect that an image in which a decrease in brightness is suppressed can be acquired even if the imaging frame rate is increased.

FIG. 1 is a diagram showing a schematic configuration of an endoscope system according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of an endoscope system according to a first embodiment of the present invention. FIG. 3 is a timing chart illustrating a normal mode imaging process performed by the endoscope system according to the first embodiment of the present invention. FIG. 4 is a timing chart illustrating a high-speed mode imaging process performed by the endoscope system according to the first embodiment of the present invention. FIG. 5 is a diagram schematically showing an example of an image acquired by the endoscope system according to the first embodiment of the present invention by an imaging process in a high-speed mode and displayed on a display device. FIG. 6 is a diagram schematically showing an example of an image acquired by the endoscope system according to the first embodiment of the present invention by the imaging process in the normal mode and displayed on the display device. FIG. 7 is a timing chart illustrating a high-speed mode imaging process performed by the endoscope system according to a modified example of the first embodiment of the present invention. FIG. 8 is a block diagram showing a schematic configuration of an endoscope system according to a second embodiment of the present invention.

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described. In the embodiment, as an example of the endoscope system according to the present invention, a medical endoscope system that captures and displays an image in a subject such as a patient will be described. Moreover, this embodiment does not limit the present invention. Further, in the description of the drawings, the same parts will be described with the same reference numerals.

(Embodiment 1)
FIG. 1 is a diagram showing a schematic configuration of an endoscope system according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of the endoscope system according to the first embodiment.

The endoscope system 1 shown in FIGS. 1 and 2 includes an endoscope 2 that captures an image in a subject by inserting a tip into the subject, and illumination light emitted from the tip of the endoscope 2. A processing device 3 and a processing device 3 that have an illumination unit 3a for generating light, perform predetermined signal processing on the image pickup signal captured by the endoscope 2, and collectively control the operation of the entire endoscope system 1. It is provided with a display device 4 for displaying an in-vivo image generated by the signal processing of the above.

The endoscope 2 has a flexible and elongated insertion portion 21, an operation portion 22 connected to the base end side of the insertion portion 21 and receiving input of various operation signals, and an insertion portion from the operation unit 22. It includes a universal cord 23 that extends in a direction different from the extending direction of 21 and incorporates various cables that connect to the processing device 3 (including the lighting unit 3a).

The insertion portion 21 is a bendable portion composed of a tip portion 24 having a built-in image pickup element 244 in which pixels that generate a signal by receiving light and performing photoelectric conversion are arranged in a two-dimensional manner, and a plurality of bending pieces. It has a curved portion 25 and a long flexible tube portion 26 connected to the proximal end side of the curved portion 25 and having flexibility. The insertion unit 21 is inserted into the body cavity of the subject and images a subject such as a living tissue at a position where outside light does not reach by the image sensor 244.

The tip portion 24 includes a light guide 241 configured by using a glass fiber or the like and forming a light guide path for light emitted by the illumination portion 3a, an illumination lens 242 provided at the tip of the light guide 241, and optics for condensing light. An image pickup element 244 (imaging unit) provided at an imaging position of the system 243 and the optical system 243, receiving light collected by the optical system 243 and photoelectrically converting it into an electric signal to perform predetermined signal processing, and a memory. It has 245 and.

The optical system 243 is configured by using one or more lenses, and has an optical zoom function for changing the angle of view and a focus function for changing the focus.

The image sensor 244 photoelectrically converts the light from the optical system 243 to generate an electric signal (image signal). Specifically, in the image sensor 244, a plurality of pixels each having a photodiode that stores a charge according to the amount of light, a capacitor that converts the charge transferred from the photodiode into a voltage level, and the like are arranged in a matrix. The light receiving unit 244a, in which each pixel photoelectrically converts the light from the optical system 243 to generate an electric signal, and the electric signal generated by the pixel arbitrarily set as the reading target among the plurality of pixels of the light receiving unit 244a are sequentially read out. Therefore, it has a reading unit 244b that outputs as an image signal, and a binning control unit 244c that controls the pixel unit read by the reading unit 244b according to the imaging conditions. The image sensor 244 is realized by using, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

The memory 245 stores data including an execution program and a control program for the image sensor 244 to execute various operations, and identification information of the endoscope 2. The identification information includes the unique information (ID) of the endoscope 2, the model year, the spec information, the transmission method, and the like. Further, the memory 245 may temporarily store the image data or the like generated by the image pickup device 244. The memory 245 is composed of a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, and the like.

The operation unit 22 includes a bending knob 221 that bends the curved part 25 in the vertical and horizontal directions, and a treatment tool insertion part 222 that inserts a treatment tool such as a biopsy forceps, an electric knife, and an examination probe into the body cavity of the subject. In addition to the processing device 3, there are a plurality of switches 223, which are operation input units for inputting operation instruction signals of peripheral devices such as air supply means, water supply means, and screen display control. The treatment tool inserted from the treatment tool insertion portion 222 is exposed from the opening (not shown) via the treatment tool channel (not shown) of the tip portion 24.

The universal cord 23 includes at least a light guide 241 and a collective cable 246 that bundles one or a plurality of signal lines. The collecting cable 246 includes information including a signal line for transmitting an image pickup signal, a signal line for transmitting a drive signal for driving the image pickup element 244, and unique information about the endoscope 2 (image pickup element 244). Includes signal lines for transmitting and receiving. In the present embodiment, the electric signal is transmitted using the signal line, but the optical signal may be transmitted, or the endoscope 2 and the processing device 3 are connected by wireless communication. Signals may be transmitted between them.

Next, the configuration of the processing device 3 will be described. The processing device 3 includes an illumination unit 3a, an image processing unit 31, a frame memory 32, a communication unit 33, an imaging condition switching unit 34, a synchronization signal generation unit 35, an input unit 36, and a storage unit 38. A control unit 37 is provided.

First, the configuration of the lighting unit 3a will be described. The illumination unit 3a includes a light source unit 310 and an illumination control unit 320.

The light source unit 310 is configured by using a plurality of light sources that emit a plurality of illumination lights having different wavelength bands, a plurality of lenses, and the like, and emits illumination light including light in a predetermined wavelength band by driving each light source. To do. Specifically, the light source unit 310 emits the light source driver 311 and the first light source 312V that emits light in the wavelength band of 360 to 400 nm (violet light) and light (blue light) in the wavelength band of 400 to 495 nm. The second light source 312B, the third light source 312G that emits light in the wavelength band of 495 to 570 nm (green light), the fourth light source 312A that emits light in the wavelength band of 590 to 620 nm (amber light), and 620- A fifth light source 312R that emits light (red light) in the wavelength band of 750 nm, a lens 313V that collects violet light emitted by the first light source 312V, and a lens that collects blue light emitted by the second light source 312B. The 313B, the lens 313G that collects the green light emitted by the third light source 312G, the lens 313A that collects the amber light emitted by the fourth light source 312A, and the red light emitted by the fifth light source 312R. The lens 313R, the dichroic mirror 314V that transmits light in the wavelength band emitted by the first light source 312V, and the dicroic mirror 314V that transmits light in the other light source, and the light in the wavelength band emitted by the second light source 312B are bent, and other The dichroic mirror 314B that transmits light in the wavelength band and the dichroic mirror 314G that transmits light in the other wavelength band while bending the light in the wavelength band emitted by the third light source 312G and the wavelength band emitted by the fourth light source 312A. The dichroic mirror 314A that bends the light of the other wavelength band and transmits the light of the other wavelength band, and the dichroic mirror 314R that bends the light of the wavelength band emitted by the fifth light source 312R and transmits the light of the other wavelength band. It has a lens 315 that guides the wavelength emitted by the light source to the light guide 241. Each light source is realized by using an LED light source, a laser light source, or the like. The dichroic mirrors 314V, 314B, 314G, 314A, and 314R bend the light from the light source and travel on the same optical axis.
In the first embodiment, it is sufficient that the illumination light of each color of red, blue and green can be emitted, and at least the second light source 312B, the third light source 312G, and the fifth light source 312R may be provided. Lenses and dichroic mirrors are provided depending on the light source to be arranged.

Under the control of the illumination control unit 320, the light source driver 311 supplies light to each light source to emit light to the light source.
In the light source unit 310, light is emitted to the first light source 312V and the second light source 312B to be blue illumination light, and light is emitted to the third light source 312G to be green illumination light, and the fourth light source 312A and the fifth light source unit 310. Light is emitted from the light source 312R to emit illumination light of each color as red illumination light.
In the following, the red (R) illumination light, the green (G) illumination light, and the blue (B) illumination light are simply referred to as R illumination light, G illumination light, and B illumination light, respectively.

The illumination control unit 320 controls the amount of electric power supplied to each light source and controls the drive timing of each light source based on the control signal (dimming signal) from the control unit 37.

The image processing unit 31 receives image data of illumination light of each color captured by the image sensor 244 from the endoscope 2. When the image processing unit 31 receives analog image data from the endoscope 2, it performs A / D conversion to generate a digital image pickup signal. Further, when the image processing unit 31 receives the image data as an optical signal from the endoscope 2, it performs photoelectric conversion to generate digital image data.

The image processing unit 31 performs predetermined image processing on the image data received from the endoscope 2 to generate an image and outputs the image to the display device 4. Here, the predetermined image processing includes simultaneous processing, gradation correction processing, color correction processing, and the like. In the simultaneous processing, R image data based on the image data generated by the image sensor 244 when the light source unit 310 is irradiated with the R illumination light, and G based on the image data generated by the image sensor 244 when the light source unit 310 is irradiated with the G illumination light. This is a process in which the image data and the B image data based on the image data generated by the image sensor 244 when the light source unit 310 is irradiated with the B illumination light are simultaneously processed. The gradation correction process is a process for correcting gradation on image data. The color correction process is a process for performing color tone correction on image data. The image processing unit 31 generates a processed imaging signal (hereinafter, also simply referred to as an imaging signal) including the internal image generated by the above-mentioned image processing. The image processing unit 31 may adjust the gain according to the brightness of the image. The image processing unit 31 is configured by using a general-purpose processor such as a CPU (Central Processing Unit) or a dedicated processor such as various arithmetic circuits that execute a specific function such as an ASIC (Application Specific Integrated Circuit).

Further, the image processing unit 31 has a frame memory 32 that holds R image data, G image data, and B image data.

When the endoscope 2 is connected, the communication unit 33 acquires the unique information stored in the memory 245 of the endoscope 2. The communication unit 33 is configured by using a general-purpose processor such as a CPU or a dedicated processor such as various arithmetic circuits that execute a specific function such as an ASIC.

The imaging condition switching unit 34 switches the imaging condition based on the unique information of the endoscope 2 acquired by the communication unit 33 with reference to the information stored in the storage unit 38. Specifically, the imaging condition switching unit 34 is whether the connected endoscope 2 is an endoscope capable of supporting a surface sequential method (hereinafter, also simply referred to as high-speed surface sequential) in which the imaging frame rate is increased. Judging whether or not, if high-speed surface sequential support is possible, switch to high-speed mode in which the high-speed surface sequential method is executed. On the other hand, if the connected endoscope 2 does not correspond to the high-speed surface sequence, the imaging condition switching unit 34 switches to the normal mode in which the imaging frame rate is lower than the high-speed mode. In the first embodiment, an example in which the imaging frame rate in the high-speed mode is 120 fps (1 frame: 1/120 second) and the normal mode is 60 fps (1 frame: 1/60 second) will be described. Further, in the high-speed mode, the number of binning, which is a pixel reading unit, is set to 4 pixels, and in the normal mode, the number of binning is set to 1 pixel. The imaging conditions of the normal mode and the high-speed mode are set in advance and stored in the storage unit 38.

The synchronization signal generation unit 35 generates a clock signal (synchronization signal) that serves as a reference for the operation of the processing device 3, and uses the generated synchronization signal as the illumination unit 3a, the image processing unit 31, the control unit 37, and the endoscope 2. Output to. Here, the synchronization signal generated by the synchronization signal generation unit 35 includes a horizontal synchronization signal and a vertical synchronization signal.
Therefore, the illumination unit 3a, the image processing unit 31, the control unit 37, and the endoscope 2 operate in synchronization with each other by the generated synchronization signal.

The input unit 36 is realized by using a keyboard, a mouse, a switch, and a touch panel, and receives inputs of various signals such as an operation instruction signal for instructing the operation of the endoscope system 1. The input unit 36 may include a switch provided in the operation unit 22 and a portable terminal such as an external tablet computer.

The storage unit 38 stores data including various programs for operating the endoscope system 1 and various parameters necessary for the operation of the endoscope system 1. In addition, the storage unit 38 stores the identification information of the processing device 3. Here, the identification information includes the unique information (ID) of the processing device 3, the model year, the spec information, and the like. In addition, the storage unit 38 has an imaging information storage unit 381 that stores information regarding imaging conditions for controlling the endoscope 2 and the illumination unit 3a to perform imaging. In the image pickup information storage unit 381, for example, the read timing of the image sensor 244, the setting of the number of pixels (binning number) as the read unit, and the emission timing of the illumination light of the illumination unit 3a are set for each image pickup condition (mode). It is remembered.

In addition, the storage unit 38 stores various programs including an image acquisition processing program for executing the image acquisition processing method of the processing device 3. Various programs can be recorded on a computer-readable recording medium such as a hard disk, flash memory, CD-ROM, DVD-ROM, or flexible disk and widely distributed. The various programs described above can also be acquired by downloading them via a communication network. The communication network referred to here is realized by, for example, an existing public line network, LAN (Local Area Network), WAN (Wide Area Network), etc., and may be wired or wireless.

The storage unit 38 having the above configuration is realized by using a ROM (Read Only Memory) in which various programs and the like are pre-installed, and a RAM, a hard disk, and the like that store arithmetic parameters and data of each process.

The control unit 37 performs drive control of each component including the image sensor 244 and the illumination unit 3a, input / output control of information to each component, and the like. The control unit 37 refers to the control information data for image pickup control (for example, read timing) stored in the storage unit 38, and takes an image as a drive signal via a predetermined signal line included in the collective cable 246. It transmits to the element 244. The control unit 37 is configured by using a general-purpose processor such as a CPU or a dedicated processor such as various arithmetic circuits that execute a specific function such as an ASIC.

The display device 4 displays a display image corresponding to the image signal received from the processing device 3 (image processing unit 31) via the video cable. The display device 4 is configured by using a monitor such as a liquid crystal or an organic EL (Electro Luminescence).

Subsequently, the image acquisition process performed by the endoscope system 1 will be described. FIG. 3 is a timing chart illustrating a normal mode imaging process performed by the endoscope system according to the first embodiment of the present invention. FIG. 4 is a timing chart illustrating a high-speed mode imaging process performed by the endoscope system according to the first embodiment of the present invention.

In FIGS. 3 and 4, from the top, (a) indicates a frame counter, (b) indicates an illumination light irradiation timing and an image pickup timing, and (c) to (e) are colors held by the frame memory 32. (F) to (h) indicate the timing of the image data of each color output by the image processing unit 31. Further, in FIG. 3, the control unit 37 causes the image sensor 244 to image at 60 fps, and the illumination control unit 320 causes the light source unit 310 to image the R illumination light, the G illumination light, and the light source unit 310 at 60 fps in synchronization with the image pickup frame rate of the image sensor 244. B Illumination light is sequentially switched and irradiated. On the other hand, in FIG. 4, the image sensor 244 is imaged at 120 fps in the high-speed mode, and the illumination control unit 320 causes the light source unit 310 to perform R illumination light, G illumination light, and B at 120 fps in synchronization with the image pickup frame rate of the image sensor 244. The illumination light is switched in sequence to irradiate. Even in the high-speed mode, the frame rate at which the display device 4 switches images is set to 60 fps as in the normal mode.

(Normal mode: Fig. 3)
First, the illumination control unit 320 causes the light _{source unit 310 to irradiate the R 0} illumination light at the timing of the frame counter (FC) = 0. In this case, the control unit 37 _{causes the image sensor 244 to image the return light due to the R 0} illumination light, and causes the image processing unit 31 to output the image data. The image processing unit 31 stores digital R ₀ image data in the corresponding channel (frame memory R) of the frame memory 32, and performs various image processing. In the normal mode, processing of one frame is performed for 1/60 second.

_{Subsequently, the control unit 37 causes the image processing unit 31 to output the R 0} image data of the frame memory 32 to the display device 4 at the timing of FC = 1. In this case, the illumination control unit 320 causes the light _{source unit 310 to irradiate the G 0 illumination light.} At this time, the control unit 37 _{causes the image sensor 244 to image the return light from the G 0} illumination light, and causes the image processing unit 31 to output the image data. The image processing unit 31 stores digital G ₀ image data in the corresponding channel (frame memory G) of the frame memory 32, and performs various image processing.

After that, the control unit 37 _{causes the image processing unit 31 to output the G 0} image data of the frame memory 32 to the display device 4 at the timing of FC = 2. In this case, the illumination control unit 320 causes the light _{source unit 310 to irradiate the B 0 illumination light.} At this time, the control unit 37 causes the imaging return light by B ₀ the illumination light to the image sensor 244 to output the image data to the image processing unit 31. The image processing unit 31 stores digital B ₀ image data in the corresponding channel (frame memory B) of the frame memory 32, and performs various image processing.

_{Subsequently, the control unit 37 causes the image processing unit 31 to output the B 0} image data of the frame memory 32 to the display device 4 at the timing of FC = 3.

In the normal mode described above, the illumination control unit 320 sequentially repeats the cycle of R illumination light → G illumination light → B illumination light as one cycle until the end of shooting. Further, in the normal mode, since the number of binning is set to one pixel, the reading unit 244b sequentially reads the pixel value with one pixel as a reading unit.

(High-speed mode: Fig. 4)
In the high-speed mode, the illumination control unit 320 and the control unit 37 irradiate the light source unit 310 with illumination light in the same manner as in the normal mode except that the image pickup frame rate is set to 120 fps, and the image sensor 244 is backlit by the illumination light. Is imaged, and the image data is output to the image processing unit 31. In the high-speed mode, the number of binnings is further set as an imaging condition. As the number of binning, 4 pixels, 9 pixels, and 16 pixels are set depending on the characteristics of the endoscope 2 and the like. For example, when the number of binning is 4 pixels, 4 pixels forming a shape similar to one pixel are read as one pixel. In the high-speed mode, processing of one frame for 1/120 second is performed.

In the high-speed mode described above, the illumination control unit 320 sequentially repeats the cycle of R illumination light → G illumination light → B illumination light as one cycle until the end of shooting. Further, in the high-speed mode, since the number of binning is set to 4 pixels, the reading unit 244b sequentially reads the pixel values obtained by combining the 4 pixels as one reading unit. Therefore, the pixel value can be increased as compared with the case where the read unit is one pixel.

FIG. 5 is a diagram schematically showing an example of an image acquired by the endoscope system according to the first embodiment of the present invention by an imaging process in a high-speed mode and displayed on a display device. FIG. 6 is a diagram schematically showing an example of an image acquired by the endoscope system according to the first embodiment of the present invention by the imaging process in the normal mode and displayed on the display device. In FIGS. 5 and 6, from the top, (R1) and (R2) show scenes, captured images, and display images captured by the R illumination light, and (G1) and (G2) are captured by the G illumination light. The scene, the captured image, and the display image are shown, and (B1) and (B2) indicate the scene, the captured image, and the display image captured by the B illumination light.

As can be seen from FIGS. 5 and 6, the display image having a high imaging frame rate has a smaller feeling of color shift than the display image having a low imaging frame rate. Specifically, the deviation of the image of each color in the area Q of the display image is smaller in the display image having a high imaging frame rate than in the display image having a low imaging frame rate.

In the first embodiment described above, when the endoscope 2 corresponds to high-speed surface sequential, the control unit 37 sets the high-speed mode and controls illumination and imaging at 120 fps. Further, in the high-speed mode, the reading process is performed with the number of binnings larger than that in the normal mode. According to the first embodiment, the color shift can be suppressed by imaging at 120 fps, and the decrease in the brightness of the image can be suppressed even if the frame rate is set high by executing the binning process.

In the first embodiment, the gain value may be switched according to the set imaging frame rate. When switching the gain value by the image pickup element 244 side, for example, the 60 fps 12000e ^- set, in 120 fps 8000E ^- set to. Not limited to the image sensor 244, when the gain is adjusted by the image processing unit 31 of the processing device 3, the gain value may be switched according to the image pickup frame rate. Further, instead of the binning process, the brightness of the image may be ensured by the above-mentioned gain value switching process.

Further, in the first embodiment, the imaging condition switching unit 34 may switch the imaging frame rate based on the motion vector when the endoscope 2 capable of sequentially supporting high-speed surfaces is connected. Specifically, the image processing unit 31 periodically detects the motion vector of the subject from the images having different acquisition times. The imaging condition switching unit 34 calculates the magnitude of the detected motion vector, and if this magnitude is equal to or greater than a preset threshold value, the imaging frame rate is increased, and if it is smaller than the threshold value, the imaging frame rate is increased. Set the rate to a normal value. By controlling the imaging frame rate based on the motion vector, when the motion of the subject is large, the imaging frame rate is increased to suppress the color shift.

Further, in the first embodiment, the imaging condition switching unit 34 may switch the number of binnings based on the exposure time at the time of imaging. Specifically, the imaging condition switching unit 34 acquires the latest exposure time, and if the exposure time is equal to or less than a preset threshold value, the number of binnings is increased to increase the brightness per image. To do. On the other hand, the imaging condition switching unit 34 determines that a certain degree of brightness is secured if the exposure time is longer than the threshold value, and reduces the number of binnings as compared with the case where the exposure time is equal to or less than the threshold value.

(Modified Example of Embodiment 1)
Next, a modified example of the first embodiment of the present invention will be described with reference to FIG. 7. FIG. 7 is a timing chart illustrating a high-speed mode imaging process performed by the endoscope system according to a modified example of the first embodiment of the present invention. Since the endoscope system according to this modification has the same configuration as the endoscope system described above, the description thereof will be omitted. Hereinafter, processing different from that of the first embodiment will be described.

According to the standard luminous efficiency defined by the CIE (Commission Internationale de l'Eclairage), humans perceive green light (light in the wavelength band including wavelength 555 nm) most strongly in bright places. For example, under the situation shown in FIG. 3, the image displayed by the display device 4 at the timing of FC = 3 has the color order of the output from the image processing unit 31 G ₀ → B ₀ → R ₁ (G ₀ image data →). B ₀ image data → R ₁ image data), and the two colors (G and R) with high human visual sensitivity are output at timings that are separated in time. Furthermore, according to the above-mentioned standard luminosity factor, human beings strongly perceive red light (wavelength 620-700 nm) next to green light among the three primary colors RGB. As a result, the user visually feels a large color shift.

Further, under the situation shown in FIG. 3, the color order of the output from the image processing unit 31 of the image displayed by the display device 4 at the timing of FC = 4 is B ₀ → R ₁ → G ₁ (B ₀ data → R). ₁ data → G ₁ data), and the two colors (G and R) with high human visual sensitivity are output at the timing when they are adjacent in time. Therefore, the color shift that the user perceives visually is smaller than the timing at which the two colors (G and R) having high human visual sensitivity are separated in time. Further, in the image displayed by the display device 4 at the timing of FC = 5, the color order of the output from the image processing unit 31 is R ₁ → G ₁ → B ₁ (R ₁ data → G ₁ data → B ₀ data). , Two colors (G and R) with high human visual sensitivity are output at timings adjacent to each other in time. Therefore, the color shift that the user perceives visually is smaller than the timing at which the two colors (G and R) having high human visual sensitivity are separated in time.

Next, the operation executed by the endoscope system 1 in this modified example will be described with reference to FIG. 7. In FIG. 7, from the top, (a) indicates the frame counter, (b) indicates the irradiation timing of the illumination light, and (c) to (e) indicate the timing of the image data of each color held by the frame memory 32. (F) to (h) show the timing of the image data of each color output by the image processing unit 31. Further, in FIG. 7, the control unit 37 images the image sensor 244 at 120 fps, and the illumination control unit 320 sequentially switches the illumination light to the light source unit 310 at 120 fps in synchronization with the image pickup frame rate of the image sensor 244 to irradiate the light source unit 310. Indicates high speed mode.

First, the illumination control unit 320 causes the light _{source unit 310 to irradiate the G 0 illumination light at the timing of FC = 0.} In this case, the control unit 37 _{causes the image sensor 244 to image the return light from the G 0} illumination light, and causes the image processing unit 31 to output the image data. The image processing unit 31 stores the G ₀ image data in the corresponding channel (frame memory G) of the frame memory 32, and performs various image processing. _{Further, the control unit 37 causes the image processing unit 31 to output the G 0} image data of the frame memory 32 to the display device 4 at the timing of FC = 0.

Subsequently, the illumination control unit 320 causes the light _{source unit 310 to irradiate the R 0 illumination light.} In this case, the control unit 37 _{causes the image sensor 244 to image the return light due to the R 0} illumination light, and causes the image processing unit 31 to output the image data. The image processing unit 31 stores digital R ₀ image data in the corresponding channel (frame memory R) of the frame memory 32, and performs various image processing. At this time, the control unit 37 _{causes the image processing unit 31 to output the R 0} image data of the frame memory 32 to the display device 4 at the timing of FC = 1.

After that, the illumination control unit 320 causes the light _{source unit 310 to irradiate the G 1 illumination light.} In this case, the control unit 37 _{causes the image sensor 244 to image the return light from the G 1} illumination light, and causes the image processing unit 31 to output the image data. The image processing unit 31 stores digital G ₁ image data in the corresponding channel (frame memory G) of the frame memory 32, and performs various image processing. At this time, the control unit 37 _{causes the image processing unit 31 to output the G 1} image data of the frame memory 32 to the display device 4 at the timing of FC = 2.

Subsequently, the illumination control unit 320 causes the light _{source unit 310 to irradiate the B 0 illumination light.} In this case, the control unit 37 _{causes the image sensor 244 to image the return light from the B 0} illumination light, and causes the image processing unit 31 to output the image data. The image processing unit 31 stores digital B ₀ image data in the corresponding channel (frame memory B) of the frame memory 32, and performs various image processing. At this time, the control unit 37 _{causes the image processing unit 31 to output the B 0} image data of the frame memory 32 to the display device 4 at the timing of FC = 3.

In the modification described above, the illumination control unit 320 sequentially switches the illumination light to the light source unit 310 until the end of imaging, with the process of G illumination light → R illumination light → G illumination light → B illumination light as one cycle. In this case, the control unit 37 is at the timing when the frame counter becomes an odd number (for example, FC = 3, FC = 5, etc.), and the B illumination light (B ₀ illumination light) or the R illumination light (R ₁ illumination light). The image processing unit 31 is irradiated with the image corresponding to the image data composed _{of the R 0} image data, the G ₁ image data, and the B _{0 image data, the R 1} image data, the G ₂ image data, and the B ₀ image. The image corresponding to the image data composed of the data is output to the display device 4. As a result, the G image data is constantly updated, so that it is possible to prevent color shifts that can be visually grasped. Further, when the transfer rate (display frame rate) to the display device 4 is 60 fps, the endoscope system 1 doubles the switching rate of the illumination light emitted by the light source unit 310 (the image pickup frame rate of the image pickup element 244). It can be 120 fps.

Further, in this modification, the illumination control unit 320 is not a simple repetition of the three primary colors of the conventional method described above (R illumination light → G illumination light → B illumination light), but is a green light having high human visual sensitivity. In a color order that doubles the time resolution of red light and blue light, specifically, G illumination light → R illumination light → G illumination light → B illumination light is sequentially switched to the illumination unit 3a for irradiation. Therefore, the smoothness of movement can be improved.

Further, in this modification, the illumination control unit 320 irradiates the light source unit 310 with illumination light in the order of G illumination light → R illumination light → G illumination light → B illumination light, and two colors with high visual sensitivity, that is, G illumination light. By adjoining the R illumination light and the R illumination light in time, it is possible to prevent the G illumination light and the R illumination light from being separated in time, so that the feeling of color shift can be reduced when capturing a still image at an arbitrary timing. Can be done.

(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a block diagram showing a schematic configuration of an endoscope system according to a second embodiment of the present invention.

The endoscope system 1A shown in FIG. 8 generates an endoscope 2 that captures an image in the subject by inserting the tip portion into the subject, and an illumination light emitted from the tip of the endoscope 2. A processing device 3A having an illumination unit 3a, performing predetermined signal processing on the image pickup signal captured by the endoscope 2, and comprehensively controlling the operation of the entire endoscope system 1, and signal processing of the processing device 3A. It is provided with a display device 4 for displaying an in-vivo image generated by the above. The endoscope system 1A according to the second embodiment has the same configuration except that the processing device 3 of the endoscope system 1 described above is changed to the processing device 3A. Hereinafter, the processing apparatus 3A having a configuration different from that of the first embodiment will be described.

The processing device 3A includes an illumination unit 3a, an image processing unit 31, a frame memory 32, a communication unit 33, an imaging condition switching unit 34, a synchronization signal generation unit 35, an input unit 36, and a control unit 37. A storage unit 38 and an enlargement processing unit 39 are provided. The processing device 3A has a configuration in which an expansion processing unit 39 is added to the above-mentioned processing device 3. Hereinafter, the enlargement processing unit 39 will be described.

The enlargement processing unit 39 switches the electronic enlargement ratio of the image data according to the set number of binning. Here, since the binning-processed image data treats four pixels as one point on the image, the size of the image becomes small. The enlargement processing unit 39 interpolates and enlarges the image data to suppress the reduction of the image due to the binning process. For example, when the number of binning is 4 pixels, it is not enlarged (1 time), and when the number of binning is 9 pixels, it is enlarged twice.

In the second embodiment described above, the same effect as that of the first embodiment described above can be obtained. Further, according to the second embodiment, since the image is enlarged according to the number of binnings, it is possible to prevent the image displayed on the display device 4 from being reduced.

In the above-described first and second embodiments, the illumination unit 3a has been described as being formed separately from the endoscope 2, but for example, a semiconductor light source is provided at the tip of the endoscope 2. The light source device may be provided in the endoscope 2. Further, the endoscope 2 may be provided with the function of the processing device 3.

Further, in the above-described first and second embodiments, the binning control unit 244c has been described as being provided on the image pickup device 244, but it may be provided outside the image pickup device 244 (inside the endoscope 2) or processed. It may be provided in the devices 3 and 3A.

Further, in the above-described first and second embodiments, the lighting unit 3a has been described as being integrated with the processing devices 3 and 3A, but the lighting unit 3a and the processing device 3 are separate bodies, for example, the processing device. A light source unit 310 and a lighting control unit 320 may be provided outside the third unit.

Further, in the above-described first and second embodiments, the illumination unit 3a has a white wavelength (for example, a xenon lamp or a halogen lamp) instead of the LED light source, and a red wavelength on the optical path of the illumination light emitted by the white light source. Illumination including each of the red, green, and blue wavelength bands by providing a rotation filter having three transmission filters that transmit each of the band, the green wavelength band, and the blue wavelength band, and rotating the rotation filter. You may irradiate light.

Further, in the above-described first and second embodiments, when the video output method is switched between NTSC displaying 60 fields per second and PAL displaying 50 fields per second, images are thinned out at the time of switching. At this time, a number is assigned to the image before it is thinned out for the method conversion, and the number and the parameter related to the image data of the number are stored in a memory (for example, provided in the display device 4). After the switching process is completed, the image data of each number and its parameters are read out, and the process for displaying is continued.

Further, in the above-described first and second embodiments, when an optical cable made of an optical fiber is connected by an optical connector in order to perform optical transmission between the patient substrate and the secondary substrate in the processing devices 3 and 3A. The optical fiber may be configured to notify the replacement time before the image data (optical signal) is no longer transmitted due to aged deterioration. For example, the deterioration is determined by monitoring the optical transmission current on the signal receiving side of the optical connector, converting the monitor value into a voltage, and comparing it with the threshold value.

Further, in the above-described first and second embodiments, the endoscope system according to the present invention is an endoscope system 1 using a flexible endoscope 2 whose observation target is a living tissue in a subject or the like. Although it was explained as a thing, it is used for the eyepieces of rigid endoscopes, industrial endoscopes for observing the characteristics of materials, capsule-type endoscopes, fiberscopes, optical endoscopes, and other optical endoscopes. It can also be applied to an endoscope system using a camera head connected.

As described above, the endoscope system according to the present invention is useful for acquiring an image in which a decrease in brightness is suppressed even if the imaging frame rate is increased.

1 Endoscope system 2 Endoscope 3 Processing device 3a Lighting unit 4 Display device 21 Insertion unit 22 Operation unit 23 Universal cord 24 Tip part 25 Curved part 26 Flexible tube part 31 Image processing unit 32 Frame memory 33 Communication unit 34 Imaging Condition switching unit 35 Synchronous signal generation unit 36 Input unit 37 Control unit 38 Storage unit 381 Imaging information storage unit 310 Light source unit 320 Lighting control unit

Claims (4)

An illumination unit that sequentially switches a plurality of illumination lights including different wavelength bands to irradiate the subject.
An endoscope having a plurality of pixels that photoelectrically convert the return light from the subject to generate an image signal, and an imaging unit that reads out the image signal generated by the pixels in synchronization with the irradiation timing of the illumination unit. With a mirror
An image processing unit that performs simultaneous processing on the image signals read by the imaging unit using a plurality of the image signals generated based on return light of illumination light having different wavelength bands.
Based on the identification information of the endoscope, the mode can be set to either a normal mode in which the imaging unit is made to image at a preset imaging frame rate or a high-speed mode in which the imaging frame rate is higher than the normal mode. Imaging condition switching unit to switch and
When the high-speed mode is set, the binning control unit causes the imaging unit to execute the reading process by increasing the number of pixels as the reading unit as compared with the normal mode.
An endoscopic system characterized by being equipped with. The lighting unit
A red semiconductor light emitting device that emits red illumination light in the red wavelength band,
A green semiconductor light emitting device that emits green illumination light in the green wavelength band,
A blue semiconductor light emitting device that emits blue illumination light in the blue wavelength band,
An illumination control unit that switches the emission of illumination light from the red semiconductor light emitting element, the green semiconductor light emitting element, and the blue semiconductor light emitting element according to the setting of the imaging frame rate.
Have,
When the high-speed mode is set, the lighting control unit is characterized in that the lighting order of the illumination lights is the red illumination light, the green illumination light, the blue illumination light, and the green illumination light. The endoscopic system according to claim 1. Enlargement processing unit that performs electronic enlargement processing on the image signal,
With more
The endoscope system according to claim 1, wherein the enlargement processing unit switches the electron enlargement ratio according to the number of pixels as the read unit executed by the binning control unit in the imaging unit. The endoscope system according to claim 1, wherein the imaging condition switching unit switches the imaging frame rate and / or the number of pixels as the reading unit based on the parameters related to the image signal.

Images