JP7055625B2 - Endoscope device - Google Patents

Description

The present invention relates to an endoscope device.

Conventionally, an endoscope device that captures a subject by using an image pickup device and observes the subject is required to increase the resolution of the captured image in order to obtain a more precise observation image. Examples of the endoscope device include an endoscope that is inserted into a subject and captures light from a subject, and an image pickup device that has an image pickup element that receives light captured by the endoscope and converts it into an electric signal. There is known one provided with an image processing device that generates an image to be captured based on an electric signal generated by the image pickup device.

As a technique for increasing the resolution, the number of pixels of the image sensor is being increased. At this time, when the aperture value becomes smaller due to the increase in the number of pixels, the depth of field also becomes shallower. As a result, although the resolution of the captured image is high, the depth of field is shallow, and there is a problem that observation is difficult depending on the subject.

As a technique for increasing the depth of field, a technique for increasing the depth of field by reducing the diameter of the aperture of the aperture diaphragm is known. In this technique, it is possible to adjust the depth of field by adjusting the diameter of the aperture of the aperture stop. However, the aperture of the image pickup device is applied to the so-called small-diameter endoscope, which has a small exit pupil diameter, which is the size of the subject image formed by the observation optical system of the endoscope, to expand the depth of view. In this case, there is a possibility that the optical axis of the observation optical system of the endoscope and the aperture center of the aperture diaphragm of the image pickup device may be misaligned due to rattling when the endoscope and the image pickup device are attached. In this case, the aperture diaphragm may not be able to properly stop down the subject image, and the appropriate depth of field may not be expanded.

As another technique for expanding the depth of field, a phase modulation element is placed at the entrance pupil position of the observation optical system, and a point image distribution function (point image distribution function) is used when an image is generated based on the light passing through the phase modulation element. A method of expanding the depth of field by generating an image using a Point Spread Function (PSF) is disclosed (see, for example, Patent Document 1). Such a technique is commonly referred to as Wavefront Coding (WFC).

Further, as another technique for expanding the depth of field, for example, by performing so-called contour enhancement processing, which is an image processing for enhancing contours, at least in an out-of-focus area of the captured image, the contours are clear. It is conceivable to expand the area and increase the depth of field.

Japanese Unexamined Patent Publication No. 2012-109826

By the way, it is possible to attach different types of endoscopes having different optical characteristics to the above-mentioned image pickup apparatus. For example, an endoscope having the above-mentioned phase modulation element and an endoscope having no phase modulation element may be attached. In this way, when multiple types of endoscopes can be attached to the image pickup device, it is required to generate an image with an enlarged depth of field regardless of the type of endoscope connected to the image pickup device. Be done.

The present invention has been made in view of the above, and provides an endoscope device capable of generating an image with an enlarged depth of field regardless of the type of endoscope to be connected. The purpose.

In order to solve the above-mentioned problems and achieve the object, the endoscope device according to the present invention is different from the first endoscope having the first observation optical system and the first observation optical system. A second endoscope having a second observation optical system and having an ejection pupil diameter larger than the ejection pupil diameter of the first endoscope, and one of the first and second endoscopes. An image pickup device having an aperture diaphragm through which light from the connected endoscope is passed, and an image pickup unit that receives light that has passed through the aperture diaphragm and converts it into an electric signal, and the image pickup device. It comprises an image processing device that generates an image using the generated electric signal, and is characterized in that the minimum aperture diameter of the aperture diaphragm is larger than the ejection pupil diameter of the first endoscope.

Further, in the endoscope device according to the present invention, in the above invention, the first observation optical system includes a phase modulation element, and in the image processing device, the first endoscope is connected to the image pickup device. If this is the case, the image is generated by performing image processing using the point image distribution function.

Further, in the endoscope device according to the present invention, in the above invention, the image processing device has an identification unit for identifying an endoscope connected to the image pickup device, and the identification unit is connected to the image pickup device. When it is identified that the endoscope is the first endoscope, the image is generated by performing image processing using a point image distribution function.

Further, in the endoscope device according to the present invention, in the above invention, when the first endoscope is connected to the image pickup device, the second endoscope is said to be the image processing device. It is characterized in that the image is generated by increasing the degree of enhancement by the contour enhancement process when connected to an image pickup apparatus.

Further, in the endoscope device according to the present invention, in the above invention, the image processing device has an identification unit for identifying an endoscope connected to the image pickup device, and the identification unit is connected to the image pickup device. When it is identified that the used endoscope is the first endoscope, the degree of enhancement by the contour enhancement process is increased as compared with the case where the second endoscope is connected to the image pickup apparatus. It is characterized in that the image is generated.

Further, the endoscope device according to the present invention includes a first endoscope having a first observation optical system including a phase modulation element, and the first observation optical system not including the phase modulation element. Is connected to a second endoscope having a different second observation optical system and one of the first and second endoscopes, and receives light from the connected endoscope. The image processing device includes an image pickup device having an image pickup unit that converts the image into an electric signal, and an image processing device that generates an image using the electric signal generated by the image pickup device. When the mirror is connected to the image pickup device, the image is generated by performing image processing using the point image distribution function, and the second endoscope is connected to the image pickup device. The first endoscope is connected to the image pickup apparatus, and the degree of enhancement by the contour enhancement process is increased to generate the image.

Further, in the endoscope device according to the present invention, in the above invention, the image processing device has an identification unit for identifying an endoscope connected to the image pickup device, and the identification unit is connected to the image pickup device. When it is identified that the endoscope is the first endoscope, the image is generated by performing image processing using a point image distribution function, and the identification unit is connected to the image pickup device. When it is identified that the used endoscope is the second endoscope, the degree of enhancement by the contour enhancement process is increased as compared with the case where the first endoscope is connected to the image pickup apparatus. It is characterized in that the image is generated.

According to the present invention, there is an effect that an image with an enlarged depth of field can be generated regardless of the type of the endoscope to be connected.

FIG. 1 is a diagram showing a schematic configuration of an endoscope device according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of the camera head and the control device shown in FIG. FIG. 3A is a schematic diagram illustrating a configuration of an endoscope and a camera head according to an embodiment of the present invention. FIG. 3B is a schematic diagram illustrating a configuration of an endoscope and a camera head according to an embodiment of the present invention. FIG. 4A is a diagram illustrating an aperture diameter of an aperture diaphragm according to an embodiment of the present invention. FIG. 4B is a diagram illustrating an aperture diameter of an aperture diaphragm according to an 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 device according to the present invention, a medical endoscope device that captures and displays an image in a subject such as a patient will be described. Further, the present invention is not limited to this embodiment. Further, in the description of the drawings, the same parts will be described with the same reference numerals.

(Embodiment)
FIG. 1 is a diagram showing a schematic configuration of an endoscope device 1 according to an embodiment of the present invention. The endoscope device 1 is used in the medical field and is a device for observing a subject inside (inside a living body) an object to be observed such as a person. As shown in FIG. 1, the endoscope device 1 includes an endoscope 2, an image pickup device 3 (medical image pickup device), a display device 4, a control device 5 (image processing device), and a light source device 6. The image pickup device 3 and the control device 5 constitute a medical image acquisition system. In the first embodiment, the endoscope 2, the image pickup device 3, and the control device 5 constitute an endoscope device using an endoscope such as a rigid mirror.

In the light source device 6, one end of the light guide 7 is connected, and an illumination light such as white for illuminating the inside of the living body is supplied to the one end of the light guide 7. One end of the light guide 7 is detachably connected to the light source device 6, and the other end is detachably connected to the endoscope 2. Then, the light guide 7 transmits the light supplied from the light source device 6 from one end to the other end and supplies the light to the endoscope 2.

The image pickup apparatus 3 captures a subject image from the endoscope 2 and outputs the image pickup result. As shown in FIG. 1, the image pickup apparatus 3 includes a transmission cable 8 which is a signal transmission unit and a camera head 9. In the first embodiment, the transmission cable 8 and the camera head 9 constitute a medical imaging device.

The endoscope 2 is hard and has an elongated shape, and is inserted into a living body. Inside the endoscope 2, an observation optical system that is configured by using one or a plurality of lenses and collects a subject image is provided. The endoscope 2 emits light supplied through the light guide 7 from the tip and irradiates the living body. Then, the light (subject image) irradiated in the living body is focused by the observation optical system (lens unit 92) in the endoscope 2.

The camera head 9 is detachably connected to the base end of the endoscope 2. Then, the camera head 9 captures a subject image focused by the endoscope 2 under the control of the control device 5, and outputs an imaging signal obtained by the imaging. The detailed configuration of the camera head 9 will be described later.

One end of the transmission cable 8 is detachably connected to the control device 5 via a connector, and the other end is detachably connected to the camera head 9 via a connector. Specifically, the transmission cable 8 is a cable in which a plurality of electrical wirings (not shown) are arranged inside an outer cover, which is the outermost layer. The plurality of electric wirings are electric for transmitting the image pickup signal output from the camera head 9 to the control device 5, and the control signal, synchronization signal, clock, and electric power output from the control device 5 to the camera head 9, respectively. It is wiring.

The display device 4 displays an image generated by the control device 5 under the control of the control device 5. The display device 4 preferably has a display unit of 55 inches or more in order to facilitate an immersive feeling during observation, but the display device 4 is not limited to this.

The control device 5 processes the image pickup signal input from the camera head 9 via the transmission cable 8, outputs the image signal to the display device 4, and comprehensively controls the operations of the camera head 9 and the display device 4. do. The detailed configuration of the control device 5 will be described later.

Next, the configurations of the image pickup device 3 and the control device 5 will be described. FIG. 2 is a block diagram showing the configurations of the camera head 9 and the control device 5. Note that FIG. 2 omits the illustration of a connector that allows the camera head 9 and the transmission cable 8 to be attached to and detached from each other.

Hereinafter, the configuration of the control device 5 and the configuration of the camera head 9 will be described in this order. In the following, the main parts of the present invention will be mainly described as the configuration of the control device 5. As shown in FIG. 2, the control device 5 includes a signal processing unit 51, an image generation unit 52, a communication module 53, an input unit 54, a control unit 55, and a memory 56. The control device 5 generates a power supply voltage for driving the control device 5 and the camera head 9, supplies the power supply voltage to each part of the control device 5, and supplies the power supply to the camera head 9 via the transmission cable 8. A portion (not shown) or the like may be provided.

The signal processing unit 51 obtains a digitized image pickup signal (pulse signal) by removing noise from the image pickup signal output by the camera head 9 and performing signal processing such as A / D conversion as necessary. Output to the generation unit 52.

Further, the signal processing unit 51 generates a synchronization signal and a clock of the image pickup device 3 and the control device 5. A synchronization signal (for example, a synchronization signal indicating the imaging timing of the camera head 9) and a clock (for example, a clock for serial communication) to the image pickup device 3 are sent to the image pickup device 3 by a line (not shown), and the synchronization signal and the clock The image pickup apparatus 3 is driven based on the clock.

The image generation unit 52 generates an image signal for display displayed by the display device 4 based on the image pickup signal input from the signal processing unit 51. The image generation unit 52 executes predetermined signal processing on the image pickup signal to generate an image signal for display including a subject image. Here, the image generation unit 52 includes known image processing such as interpolation processing, color correction processing, color enhancement processing, and various image processing such as contour enhancement processing, as well as the pupil modulation filter 21f described later. The signal whose pupil function phase distribution is modulated by the above is restored, and an captured image that expands the depth of field is generated. The image generation unit 52 is restored by performing digital processing using a point image distribution function (PSF). The image generation unit 52 outputs the generated image signal to the display device 4.

The communication module 53 outputs a signal from the control device 5 including a control signal described later transmitted from the control unit 55 to the image pickup device 3. Further, the signal from the image pickup device 3 is output to each part in the control device 5. That is, the communication module 53 collectively outputs the signals from each part of the control device 5 output to the image pickup device 3 by, for example, parallel serial conversion, and the signal input from the image pickup device 3 by, for example, serial-parallel conversion or the like. It is a relay device that outputs to each part of the distribution control device 5.

The input unit 54 is realized by using a user interface such as a keyboard, a mouse, and a touch panel, and accepts input of various information.

The control unit 55 performs drive control of each component including the control device 5 and the camera head 9, input / output control of information to each component, and the like. The control unit 55 generates a control signal by referring to the communication information data (for example, communication format information) recorded in the memory 56, and the generated control signal is transmitted to the image pickup device 3 via the communication module 53. Send to. Further, the control unit 55 outputs a control signal to the camera head 9 via the transmission cable 8.

The control unit 55 has an identification unit 55a. The identification unit 55a identifies the type of the endoscope 2 connected to the camera head 9 based on the detection information output from the camera head 9.

The memory 56 is realized by using a semiconductor memory such as a flash memory or a DRAM (Dynamic Random Access Memory), and communication information data (for example, communication format information) is recorded. The memory 56 may record various programs or the like executed by the control unit 55.

From the AF processing unit that outputs the predetermined AF evaluation value of each frame based on the input frame image pickup signal, and the AF evaluation value of each frame from the AF processing unit. It may have an AF calculation unit that performs AF calculation processing such as selecting the most suitable frame or focus lens position as the in-focus position.

The signal processing unit 51, the image generation unit 52, the communication module 53, and the control unit 55 described above include a general-purpose processor such as a CPU (Central Processing Unit) having an internal memory (not shown) in which a program is recorded, or an ASIC (Application Specific Integrated). It is realized by using a dedicated processor such as various arithmetic circuits that execute a specific function such as Circuit). Further, it may be configured by using FPGA (Field Programmable Gate Array: not shown) which is a kind of programmable integrated circuit. If the FPGA is configured, a memory for storing the configuration data may be provided, and the FPGA, which is a programmable integrated circuit, may be configured by the configuration data read from the memory.

Next, a main part of the present invention will be mainly described as a configuration of the camera head 9. As shown in FIG. 2, the camera head 9 includes an aperture diaphragm 91, a lens unit 92, an image pickup unit 93, a drive unit 94, a communication module 95, a camera head control unit 97, and a detection unit 96. ..

The aperture diaphragm 91 is arranged at a position where the optical axis of the camera head 9 passes and at the position of the entrance pupil of the lens unit 92. The aperture diaphragm 91 is formed with an opening through which the light collected by the endoscope 2 passes. The aperture diaphragm 91 is composed of a shutter that can be opened and closed, and the diameter of the aperture can be changed under the control of the drive unit 94. In the present embodiment, the aperture diaphragm 91 will be described as electrically performing an operation of changing the diameter of the aperture by the drive unit 94, for example, triggered by pressing a button (not shown) provided on the camera head 9. However, the diameter of the opening may be mechanically changed by pressing a button or the like. The diameter of the opening that the opening diaphragm 91 can take will be described later.

The lens unit 92 is configured by using one or a plurality of lenses, and forms a subject image that has passed through the aperture diaphragm 91 on the image pickup surface of the image pickup element constituting the image pickup unit 93. The one or more lenses are configured to be movable along the optical axis. The lens unit 92 is provided with an optical zoom mechanism (not shown) that moves the one or a plurality of lenses to change the angle of view and a focus mechanism that changes the focal position. In addition to the optical zoom mechanism and the focus mechanism, the lens unit 92 may be provided with an optical filter (for example, a filter that cuts infrared light) that can be inserted and removed on the optical axis.

The image pickup unit 93 images a subject under the control of the camera head control unit 97. The image pickup unit 93 is configured by using an image pickup element that receives an image of a subject image formed by the lens unit 92 and converts it into an electric signal. The image pickup device is composed of a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. When the image pickup element is a CCD, for example, a signal processing unit (not shown) that performs signal processing (A / D conversion, etc.) on an electric signal (analog signal) from the image pickup element and outputs an image pickup signal is a sensor. It is mounted on a chip or the like. When the image pickup element is CMOS, for example, a signal processing unit (not shown) that performs signal processing (A / D conversion, etc.) on an electric signal (analog signal) converted from light into an electric signal and outputs an image pickup signal. ) Is included in the image pickup element. The image pickup unit 93 outputs the generated electric signal to the communication module 95.

Under the control of the camera head control unit 97, the drive unit 94 operates the shutter of the aperture diaphragm 91 to change the diameter of the aperture, or operates the optical zoom mechanism and the focus mechanism to operate the angle of view and the focus of the lens unit 92. It has a driver that changes its position.

The communication module 95 outputs the signal transmitted from the control device 5 to each unit in the camera head 9 such as the camera head control unit 97. Further, the communication module 95 converts information about the current state of the camera head 9 into a signal format corresponding to a predetermined transmission method, and outputs the converted signal to the control device 5 via the transmission cable 8. .. That is, the communication module 95 outputs the signal input from the control device 5 and the transmission cable 8 to each part of the distribution camera head 9 by, for example, serial-parallel conversion, and also outputs the signal to the control device 5 and the transmission cable 8. It is a relay device that collectively outputs signals from each part of the above by, for example, parallel serial conversion.

The detection unit 96 is provided in, for example, the endoscope 2A and the endoscope 2B, and electrically detects the arrangement of a plurality of pins having different arrangement patterns from each other. The detection unit 96 electrically detects the pin arrangement pattern when the endoscope 2 is connected. The detection unit 96 generates detection information regarding the detected pin arrangement pattern. This detection information is used for identification of the endoscope 2 by the above-mentioned identification unit 55a. The detection unit 96 generates the detection information by referring to the information read by the IC tags and barcodes provided on the endoscope 2A and the endoscope 2B, the information stored in the memory, and the like. May be good.

The camera head control unit 97 includes a drive signal input via the transmission cable 8, an instruction signal output from the operation unit by user operation to an operation unit such as a switch provided exposed on the outer surface of the camera head 9. The operation of the entire camera head 9 is controlled according to the above. Further, the camera head control unit 97 outputs information regarding the current state of the camera head 9 to the control device 5 via the transmission cable 8.

The drive unit 94, the communication module 95, the camera head control unit 97, and the detection unit 96 described above execute specific functions such as a general-purpose processor such as a CPU having an internal memory (not shown) in which a program is recorded and an ASIC. It is realized by using a dedicated processor such as various arithmetic circuits. Further, it may be configured by using FPGA which is a kind of programmable integrated circuit. If the FPGA is configured, a memory for storing the configuration data may be provided, and the FPGA, which is a programmable integrated circuit, may be configured by the configuration data read from the memory.

The camera head 9 and the transmission cable 8 may be configured with a signal processing unit that performs signal processing on the image pickup signal generated by the communication module 95 and the image pickup unit 93. Further, based on a reference clock generated by an oscillator (not shown) provided inside the camera head 9, an imaging clock for driving the imaging unit 92 and a driving clock for driving the driving unit 94 are used. It may be generated and output to the image pickup unit 92 and the drive unit 94, respectively, or based on the synchronization signal input from the control device 5 via the transmission cable 8, the image pickup unit 92, the drive unit 94, and the camera head. Timing signals for various processes in the control unit 97 may be generated and output to the image pickup unit 92, the drive unit 94, and the camera head control unit 97, respectively. Further, the camera head control unit 97 may be provided on the transmission cable 8 or the control device 5 instead of the camera head 9.

3A and 3B are schematic views illustrating the configurations of the endoscope 2 and the camera head 9 according to the embodiment of the present invention. As the endoscope 2 attached to the camera head 9, there are endoscopes 2A and 2B as shown in FIGS. 3A and 3B. The endoscopes 2A and 2B take in external light on the distal end side and connect to the camera head 9 on the proximal end side. The endoscopes 2A and 2B have different observation optical systems.

The endoscope 2A includes an observation optical system 21A inside the insertion portion 21. The observation optical system 21A includes an objective lens 21a, a first relay optical system 21b, a second relay optical system 21c, a third relay optical system 21d, and an eyepiece lens from the tip side along the optical axis NA of the observation optical system _21A . It is arranged in the order of 21e. Further, the third relay optical system 21d located on the most proximal side of the three relay optical systems is provided with a pupil modulation filter 21f which is a phase modulation element. The pupil modulation filter 21f is configured by using a phase plate, and changes the imaging characteristics of the observation optical system 21A to form a blurred intermediate image. This intermediate image is an image that does not depend on the deviation of the focal position.

In the endoscope 2B, the diameter of the insertion portion 22 is larger than the diameter of the insertion portion 21. The endoscope 2B includes an observation optical system 22A inside the insertion portion 22. The observation optical system 22A includes an objective lens 22a, a first relay optical system 22b, a second relay optical system 22c, a third relay optical system 22d, and an eyepiece lens from the tip side along the optical axis _NB of the observation optical system 22A. They are arranged in the order of 22e. The maximum diameter of the observation optical system 22A in the optical axis _NB direction is larger than the maximum diameter of the observation optical system 21A in the optical axis _NA direction.

Further, the diameter r _B of the exit pupil SB, which is the size of the subject image formed by the observation optical system 22A of the endoscope 2B, is the diameter r of the exit pupil SA formed by the observation optical system 21A of the endoscope 2A. Greater than _A. In other words, the diameter r _A of the exit pupil SA of the endoscope 2A is smaller than the diameter r _B of the exit pupil SB of the endoscope 2B.

4A and 4B are diagrams illustrating the aperture diameter of the aperture diaphragm 91 according to the embodiment of the present invention. The opening diaphragm 91 has two opening patterns, a first opening 91a (see FIG. 4A) and a second opening 91b (see FIG. 4B) in which the diameter R ₂ of the opening is smaller than the diameter R ₁ of the first opening 91a. obtain. The diameter R ₁ of the first opening 91a is larger than, for example, the diameter r _B of the exit pupil SB of the endoscope 2B. The diameter R ₂ of the second opening 91b is smaller than the diameter r _B of the exit pupil SB of the endoscope 2B and larger than the diameter r _A of the exit pupil SA of the endoscope 2A.

Further, the control device 5 identifies whether the connected endoscope 2 is the endoscope 2A or the endoscope 2B based on the detection information generated by the detection unit 96. Specifically, the identification unit 55a identifies the connected endoscope 2 based on the pin arrangement pattern detected by the detection unit 96.

In the control device 5, when the type of the endoscope 2 connected by the identification unit 55a is identified, the control unit 55 causes the image generation unit 52 to execute image processing according to the connected endoscope 2. .. Specifically, when the control unit 55 has the pupil modulation filter 21f and is identified by the identification unit 55a that the endoscope 2A having an exit pupil diameter smaller than the endoscope 2B is connected, the image generation unit 52 describes the above. The image generation process including the restoration process is performed. As a result, an image with an enlarged depth of field is generated.

On the other hand, when the identification unit 55a identifies that the endoscope 2B having an exit pupil diameter larger than the endoscope 2A is connected without the pupil modulation filter 21f, the control unit 55 tells the image generation unit 52. An image generation process other than the above-mentioned restoration process is performed. At this time, if the opening of the aperture stop 91 is the first opening 91a, an image giving priority to resolution is generated. On the other hand, if the opening of the aperture diaphragm 91 is the second opening 91b, an image in which the expansion of the depth of field is prioritized is generated, and this image has the expansion of the depth of field as compared with the case of the first opening 91a. It becomes an image. By changing the diameter of the aperture of the aperture diaphragm 91 by the user's operation, it is possible to generate an image in which either the resolution or the expansion of the depth of field is prioritized.

When the pupil modulation filter 21f is arranged in the observation optical system 21A and an image is generated based on the light passing through the pupil modulation filter 21f, the image is generated by using the point spread function (PSF). The technique of increasing the depth of field by doing so is generally called Wavefront Coding (WFC).

According to the above-described embodiment, the camera head 9 has an exit pupil SA of the endoscope 2A having a first opening 91a, a diameter _rB of the exit pupil SB of the endoscope 2B, and a pupil modulation filter 21f. Since the aperture diaphragm 91 forming the second aperture 91b having a diameter larger than the diameter r _A of the above is provided, the endoscope 2A is connected or the endoscope 2B without the pupil modulation filter 21f is connected. Even in this case, the control device 5 at the subsequent stage can generate an image with an enlarged depth of view.

Further, according to the above-described embodiment, by providing the endoscope 2A with the pupil modulation filter 21f, an image having an enlarged depth of field can be generated without narrowing down the light from the endoscope 2 having a small diameter. can do. Further, due to rattling when the endoscope 2A and the camera head 9 are attached, the optical axis NA of the observation optical system _21A of the endoscope 2A and the aperture center of the aperture diaphragm 91 of the camera head 9 are displaced. Even if this occurs, it is possible to generate an image with an appropriately enlarged depth of field. Thereby, according to the present embodiment, it is possible to generate an image with an enlarged depth of field without lowering the resolution.

Further, in the above-described embodiment, if the pupil modulation filter 21f is selectively provided according to the diameter of the insertion portion 21 of the endoscope 2 and the diameter of the exit pupil, the field of view is suppressed while suppressing the decrease in resolution. It is possible to generate an image with an enlarged depth. Therefore, it is possible to generate an image with an enlarged depth of field without providing the pupil modulation filter 21f in all endoscopes 2, and the pupil modulation filter 21f can be used for the endoscope 2 that can be used. The cost for installation can be reduced.

Here, due to the influence of chromatic aberration on the optical axis in the observation optical system, the focal position when illuminated with infrared light and the focal position when illuminated with white light are deviated from each other. Due to this deviation, there is a problem that one of the generated images is blurred when the focal position is fixed and the image is taken. According to the present embodiment, by using the above-mentioned WFC, the depth of field can be expanded including the deviation of the focal position. Therefore, the focal position is fixed and the illumination light is changed. However, it is possible to suppress the occurrence of blurring of the image. In particular, when a superposed image in which an infrared image by infrared light and a white image by white light are superposed is generated, a superimposed image having a deep depth of field and a clear superimposition can be obtained.

In the above-described embodiment, when an endoscope 2 having a pupil modulation filter and different diameters of exit pupils can be attached to the camera head 9 in addition to the endoscope 2A, the diameter R of the second opening 91b. ₂ is made larger than the maximum exit pupil diameter of the exit pupil diameters of the endoscope 2 having the pupil modulation filter. That is, the diameter R ₂ of the second opening 91b is smaller than the diameter R ₁ of the first opening 91a and larger than the maximum exit pupil diameter of the endoscope 2 having the pupil modulation filter.

Further, in the above-described embodiment, when the endoscope 2B is connected to the camera head 9, an image that prioritizes resolution and an image that prioritizes expansion of depth of field are selected according to the aperture of the aperture aperture 91. Although a possible example has been described, the opening of the opening aperture 91 may be fixed by the second opening 91b as long as it is configured to generate only an image in which the expansion of the depth of field is prioritized. That is, in the configuration of the endoscope device 1 that only generates an image in which the expansion of the depth of field is prioritized, the aperture diaphragm 91 has a hollow disk shape fixed to the second aperture 91b.

Further, in the above-described embodiment, when the endoscope 2B and the endoscope 2 having no pupil modulation filter and different diameters of the exit pupils can be attached to the camera head 9, the first aperture diaphragm 91 is used. The diameter R ₁ of the opening 91a may be variable. That is, the size of the diameter R ₁ of the first opening 91a is set to an upper limit value larger than the maximum exit pupil diameter of the exit pupil diameters of the endoscope 2 having no pupil modulation filter, and the pupil modulation filter. Of the exit pupil diameters of the endoscope 2 which does not have the above, the diameter smaller than the minimum exit pupil diameter is set as the lower limit value. Then, the diameter _R1 of the first opening 91a of the aperture diaphragm 91 is made variable so that the aperture diameter of the aperture diaphragm can be adjusted according to the connected endoscope 2.

Further, in the above-described embodiment, when the endoscope 2A does not have a pupil modulation filter, depth enlargement may be performed by image processing. In this case, the image generation unit 52 does not perform signal processing using the point image distribution function (PSF) on the image pickup signal, but performs edge enhancement processing, for example, to expand the depth of field of the image pickup image. May be generated. Specifically, when the endoscope 2A having no pupil modulation filter is connected, image processing is performed in which the degree of enhancement by the contour enhancement processing is larger than that when the endoscope 2B is connected, and the captured image is subjected to image processing. The depth of field is expanded by expanding the area with a clear outline. At this time, the parameter setting of contour enhancement can be changed by changing the intensity of contour enhancement in the region in the captured image according to the MTF (Modulation Transfer Function) characteristic of the connected endoscope 2A. May be. In this case as well, the same effect as that of the above-described embodiment can be obtained.

In the above-described embodiment, depending on the type of the connected endoscope 2, the aperture diaphragm and the wavefront coding are applied, or the aperture diaphragm and the contour enhancement process are applied to obtain the depth of field. However, the description is not limited to this, and the depth of field may be expanded by applying wavefront coding and contour enhancement processing without providing the aperture diaphragm 91. Specifically, regardless of the size of the ejection pupil diameter of the endoscope 2, when the endoscope 2 having the pupil modulation filter is connected to the camera head 9, the image generation unit 52 receives the image pickup signal. A captured image that expands the depth of field is generated by performing signal processing using the point image distribution function (PSF), and the endoscope 2 that does not have a pupil modulation filter is connected to the camera head 9. In this case, the image generation unit 52 may generate an image captured image that expands the depth of field by performing contour enhancement processing on the image pickup signal. Also in this case, it is possible to generate an image with an enlarged depth of field according to the connected endoscope 2. At this time, the degree of enhancement by the contour enhancement process may be changed according to the size of the exit pupil diameter of the endoscope 2 having no pupil modulation filter. For example, as the size of the exit pupil diameter of the endoscope 2 becomes smaller, the degree of emphasis is relatively increased.

Further, in the above-described embodiment, when the depth of field is expanded by applying the aperture diaphragm or the wavefront coding, the contour enhancement process may be further applied to further expand the depth of field. good. At that time, when the endoscope 2 to which the aperture stop and the wave surface coding are not applied is connected to the camera head 9, the endoscope 2 to which the aperture stop and the wave surface coding is applied is the camera head 9. The depth of field is expanded by increasing the degree of enhancement by the contour enhancement process when connected to. In this case as well, the same effect as that of the above-described embodiment can be obtained.

Although the embodiments for carrying out the present invention have been described so far, the present invention should not be limited only to the above-described embodiments. In the above-described embodiment, it has been described that the control device 5 performs signal processing and the like, but it may be performed on the camera head 9 side.

Further, in the above-described embodiment, it is premised that the control device 5 is connected to the image pickup device 3 which is equipped with a high-pixel image pickup element having a relatively large number of pixels and is required to increase the depth of field. However, the present invention is not limited to this, and an image pickup device (not shown) equipped with an image pickup element having a relatively small number of pixels, which does not require an expansion of the depth of field, may be selectively connected. In this case, depending on whether the image pickup device 3 is connected to the control device 5 or an image pickup device equipped with an image pickup element having a relatively small number of pixels is connected, an aperture stop for expanding the depth of field or It may be configured to selectively switch between the application of wave surface coding and contour enhancement processing and the non-application of these processing. Furthermore, depending on the type of endoscope 2 to be connected, at least one of at least two of aperture diaphragm, wavefront coding, and contour enhancement processing is applied in order to increase the depth of field. You may.

As described above, the endoscope device according to the present invention is useful for generating an image with an enlarged depth of field regardless of the type of endoscope to be connected.

1 Endoscope device 2, 2A, 2B Endoscope 3 Imaging device 4 Display device 5 Control device 6 Light source device 7 Light guide 8 Transmission cable 9 Camera head 51 Signal processing unit 52 Image generation unit 53 Communication module 54 Input unit 55 Control Section 55a Identification section 56 Memory 91 Aperture aperture 92 Lens unit 93 Imaging section 94 Drive section 95 Communication module 96 Detection section 97 Camera head control section

Claims (5)

A first endoscope having a first observation optical system and
A second endoscope having a second observation optical system different from the first observation optical system and having an exit pupil diameter larger than the exit pupil diameter of the first endoscope.
One of the first and second endoscopes is connected, and an aperture diaphragm that allows light from the connected endoscope to pass through, and an electric signal that receives light that has passed through the aperture diaphragm. An image pickup device having an image pickup unit that converts to
An image processing device that generates an image using the electric signal generated by the image pickup device, and an image processing device.
Equipped with
An endoscope device characterized in that the minimum aperture diameter of the aperture diaphragm is larger than the exit pupil diameter of the first endoscope. The first observation optical system includes a phase modulation element.
The image processing apparatus is characterized in that, when the first endoscope is connected to the image pickup apparatus, the image processing apparatus generates the image by performing image processing using a point image distribution function. The endoscope device according to 1. The image processing device is
It has an identification unit that identifies the endoscope connected to the image pickup device, and has an identification unit.
When the identification unit identifies that the endoscope connected to the image pickup apparatus is the first endoscope, the image is generated by performing image processing using a point image distribution function. 2. The endoscope device according to claim 2. The image processing device determines the degree of enhancement by contour enhancement processing when the first endoscope is connected to the image pickup device and when the second endoscope is connected to the image pickup device. The endoscope device according to claim 1, wherein the image is enlarged to generate the image. The image processing device is
It has an identification unit that identifies the endoscope connected to the image pickup device, and has an identification unit.
When the identification unit identifies that the endoscope connected to the image pickup device is the first endoscope, the case where the second endoscope is connected to the image pickup device. The endoscope device according to claim 4, wherein the image is generated by increasing the degree of enhancement by the contour enhancement process.

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