JP6227077B2 - Endoscope system and operating method thereof - Google Patents

Description

The present invention relates to an endoscope system including an electronic endoscope having a solid-state imaging device mounted on the distal end portion of the endoscope, and an operation method thereof.

  In the medical field, medical diagnosis using an endoscope system is actively performed. The endoscope system includes an electronic endoscope (scope) having an insertion portion that is inserted into a body cavity, and a main body device to which the electronic endoscope is detachably connected.

  The main device includes a processor device and a light source device. The processor device receives an imaging signal output from a solid-state imaging device built in the distal end of the insertion portion of the electronic endoscope, performs image processing, and displays the obtained observation image on a monitor. The light source device generates light that illuminates the inside of the body cavity through a light guide inserted into the electronic endoscope.

  As described in Patent Document 1, as a solid-state imaging device mounted at the distal end of an insertion portion of an electronic endoscope, a CMOS (Complementary Metal Oxide) that can be driven at a low voltage and can easily achieve a large number of pixels and high-speed readout. Semiconductor) type and CCD (Charge Coupled Device) type are used.

  An electronic endoscope is used in a special environment unlike a general digital camera or the like. For example, as shown in FIG. 7 (a), the distal end portion 1 of the electronic endoscope is inserted into the body cavity 2 which is a dark place, and the affected part 3 is photographed from a distance, or as shown in FIG. 7 (b), An enlarged image of the affected part 3 is taken by bringing the distal end part 1 of the electronic endoscope closer to the affected part 3. When approaching the affected area 3 with the intensity of the illumination light in the imaging state of FIG. 7A and making the imaging state of FIG. 7B, the illumination light is too strong and the observation image of the affected area 3 is overexposed.

  Therefore, although the intensity of the illumination light generated by the light source device is reduced, this ratio is as large as 2000: 1, for example, in an electronic endoscope. That is, it is necessary to reduce the intensity of the illumination light when the shooting state of FIG. 7A is set to about 1/2000 to the shooting state of FIG. 7B.

  In this way, another problem occurs when the intensity of the illumination light is greatly changed. FIG. 8 is a graph illustrating an example of this problem. In order to capture a color image, the illumination light includes light in the wavelength bands of the three primary colors of red (R), green (G), and blue (B). The ratio of the color components contained in the RGB illumination light changes when the intensity of the illumination light is greatly changed. For example, in the example shown in FIG. 8, when the illumination light is made stronger than when the illumination light is weak, individual light source differences such as light emission efficiency occur, and the balance of the R light quantity, G light quantity, and B light quantity changes, and R / G is While it is constant, B / G may increase.

  In such a case, a doctor who has observed an observation image of the same diseased part 3 while bringing the distal end portion 1 of the electronic endoscope close to the diseased part 3 gives an observation image in FIG. 7A and an observation image in FIG. Then, you will observe images with different colors, and you will feel uncomfortable. In particular, when surface blood vessel observation is performed, B / G needs to be constant.

JP 2009-201540 A

An object of the present invention is to provide an endoscope system that suppresses the color change of an observation image even when the brightness (intensity) of illumination light is changed, and an operation method thereof.

An endoscope system according to the present invention includes an electronic endoscope in which an illumination window for illuminating a subject with illumination light is provided at a distal end portion, and a solid-state imaging device that receives light from the subject is mounted on the distal end portion. ,
A main light source that emits blue light in the first wavelength range and an auxiliary light source that emits blue light in a second wavelength range different from the first wavelength range and is used for special light observation, each having a different wavelength A plurality of light sources that emit light of a region, a plurality of light source drive circuits that respectively drive the plurality of light sources, and a light source control unit that controls the plurality of light source drive circuits, A light source device to be introduced into the electronic endoscope;
A phosphor that absorbs light from the main light source, emits mixed light of red light and green light, and transmits most of the light from the auxiliary light source, and
The light source control unit turns on the main light source and the auxiliary light source during special light observation, and irradiates the subject with illumination light including blue light and light emitted from the phosphor. When the driving circuit is individually controlled and the light quantity of the red component of the illumination light emitted from the illumination window irradiated to the subject is R, the light quantity of the green component is G, and the light quantity of the blue component is B, B / G And R / G are made constant.
Further, according to the operation method of the endoscope system of the present invention, an illumination window for irradiating the subject with illumination light is provided at the distal end portion, and a solid-state imaging device that receives light from the subject is mounted on the distal end portion. An electronic endoscope,
A main light source that emits blue light in the first wavelength range and an auxiliary light source that emits blue light in a second wavelength range different from the first wavelength range and is used for special light observation, each having a different wavelength A plurality of light sources that emit light in a region, a light source drive circuit that drives the plurality of light sources, and a light source control unit that controls the light source drive circuit, and the light emitted from the light source is transmitted to the electronic endoscope A light source device to be introduced;
Emits mixed light of red light and green light by absorbing light from the main light source, there in operation method of the endoscope system and a phosphor having a property of hardly transmitting the light from the auxiliary light source And
Upon the light source control section, at the time of special light observation, and turns on the auxiliary light source and said main light source, emits the illumination light including the light emitted by the blue light and the phosphor for illuminating said object, When the light source drive circuit is controlled to change the light emission intensity of the main light source, the light emission intensity of the auxiliary light source is changed to change the amount of red component of the illumination light from the illumination window irradiated to the subject. When the light quantity of R and green components is G, and the light quantity of blue components is B, B / G and R / G are made constant, respectively.

  According to the present invention, it is possible to provide an easy-to-see image with no color change between a distant subject image and a close subject image.

1 is an overall configuration diagram of an endoscope system according to an embodiment of the present invention. It is a front end surface front view of the front-end | tip part of the electronic endoscope shown in FIG. It is a longitudinal cross-sectional view of the front-end | tip part of the electronic endoscope shown in FIG. It is a block block diagram of the control system of the endoscope system shown in FIG. It is a graph which shows the relationship between the emitted light amount of wavelength 445nm in the embodiment of FIG. 4, and the emitted light amount of wavelength 405nm. It is a control system block block diagram of the endoscope system of the embodiment which replaces FIG. It is explanatory drawing of the case where the affected part is image | photographed from a distance (a), and the case where it approaches and image | photographs the affected part (b). It is a characteristic view which shows an example of the change of B / G and R / G with respect to the brightness of illumination light.

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

  FIG. 1 is an overall configuration diagram showing a schematic configuration of an endoscope system according to an embodiment of the present invention. The endoscope system 10 according to the present embodiment includes an electronic endoscope 12, a processor device 14 and a light source device 16 constituting a main body device. The electronic endoscope 12 includes a flexible insertion portion 20 that is inserted into a body cavity of a patient (subject), an operation portion 22 that is connected to a proximal end portion of the insertion portion 20, a processor device 14, and a light source. And a universal cord 24 connected to the device 16.

  A distal end portion 26 is connected to the distal end of the insertion portion 20, and an imaging chip (imaging device) 54 (see FIG. 3) for intra-body cavity imaging is built in the distal end portion 26. Behind the distal end portion 26 is provided a bending portion 28 in which a plurality of bending pieces are connected. When the angle knob 30 provided in the operation section 22 is operated, the bending section 28 is bent / moved in the vertical and horizontal directions by pushing / pulling the wire inserted in the insertion section 20. Thereby, the front-end | tip part 26 is orientated in the desired direction within a body cavity.

  A connector 36 is provided at the base end of the universal cord 24. The connector 36 is of a composite type and is connected to the light source device 16 in addition to being connected to the processor device 14.

  The processor device 14 supplies power to the electronic endoscope 12 via a cable 68 (see FIG. 3) inserted into the universal cord 24, controls the driving of the imaging chip 54, and connects the cable 68 from the imaging chip 54. The received image signal is received, and various signal processing is performed on the received image signal to convert it into image data.

  The image data converted by the processor device 14 is displayed as an endoscopic image (observation image) on a monitor 38 connected to the processor device 14 by a cable. The processor device 14 is also electrically connected to the light source device 16 via the connector 36, and comprehensively controls the operation of the endoscope system 10 including the light source device 16.

  FIG. 2 is a front view showing the distal end surface 26 a of the distal end portion 26 of the electronic endoscope 12. As shown in FIG. 2, an observation window 40, an illumination window 42, a forceps outlet 44, and an air / water supply nozzle 46 are provided on the distal end surface 26 a of the distal end portion 26.

  The observation window 40 is arranged eccentric to the center and one side of the distal end surface 26a. Two illumination windows 42 are arranged at symmetrical positions with respect to the observation window 40, and irradiate illumination light from the light source device 16 to a site to be observed in the body cavity.

  The forceps outlet 44 is connected to a forceps channel 70 (see FIG. 3) disposed in the insertion portion 20 and communicates with a forceps port 34 (see FIG. 1) provided in the operation portion 22. Various treatment tools having an injection needle, a high-frequency knife or the like disposed at the distal end are inserted into the forceps port 34, and the distal ends of the various treatment instruments are ejected from the forceps outlet 44 into the body cavity.

  The air supply / water supply nozzle 46 is cleaned from the air supply / water supply device built in the light source device 16 in accordance with the operation of the air supply / water supply button 32 (see FIG. 1) provided in the operation unit 22. Water or air is jetted toward the observation window 40 or the body cavity.

  FIG. 3 is a longitudinal sectional view of the distal end portion 26 of the electronic endoscope 12. As shown in FIG. 3, a lens barrel 52 that holds an objective optical system 50 for taking in image light of a site to be observed in the body cavity is disposed behind the observation window 40. The lens barrel 52 is attached so that the optical axis of the objective optical system 50 is parallel to the central axis of the insertion portion 20. Connected to the rear end of the lens barrel 52 is a prism 56 that guides the image light of the site to be observed via the objective optical system 50 toward the imaging chip 54 by bending it at a substantially right angle.

  The imaging chip 54 is a monolithic semiconductor (so-called CMOS sensor chip) in which a CMOS solid-state imaging device 58 and a peripheral circuit 60 that drives the solid-state imaging device 58 and inputs / outputs signals are integrally formed. Implemented above.

  The imaging surface (light receiving surface) 58 a of the solid-state imaging device 58 is disposed so as to face the emission surface of the prism 56. On the imaging surface 58a, a rectangular plate-like cover glass 64 is attached via a rectangular frame-like spacer 63. The imaging chip 54, the spacer 63, and the cover glass 64 are assembled through an adhesive, and thereby the imaging surface 58a is protected from intrusion of dust and the like.

  A plurality of input / output terminals 62 a are arranged in the width direction of the support substrate 62 at the rear end portion of the support substrate 62 extending toward the rear end of the insertion portion 20. The input / output terminal 62a is joined to a signal line 66 for mediating the exchange of various signals with the processor device 14 via the universal cord 24. The input / output terminal 62a is a wiring formed on the support substrate 62. And a peripheral circuit 60 in the imaging chip 54 through a bonding pad or the like (not shown).

  The signal lines 66 are collectively inserted into a flexible tubular cable 68. The cable 68 is inserted through each of the insertion unit 20, the operation unit 22, and the universal cord 24 and is connected to the connector 36.

  Although not shown in FIGS. 2 and 3, an illumination unit is provided in the back of the illumination window 42. The illumination section is provided with an emission end 120a of a light guide 120 (see FIG. 4) for guiding illumination light from the light source device 16, and in this embodiment, a phosphor is provided between the emission end and the illumination window 42. 53 is provided. Similarly to the cable 68, the light guide 120 is inserted through each of the insertion unit 20, the operation unit 22, and the universal cord 24, and the incident end is connected to the connector 36.

  FIG. 4 is a block diagram showing a control system of the endoscope system 10. As shown in FIG. 4, a solid-state image sensor 58, an analog signal processing circuit (AFE: analog front end) 72, a TG (timing generator) 78, and a CPU 80 are provided at the distal end portion 26 of the electronic endoscope 12. Is provided.

  The TG 78 generates a driving pulse (vertical / horizontal scanning pulse, reset pulse, etc.) for the solid-state imaging device 58 and a synchronization pulse for the AFE 72 based on the control of the CPU 80. The solid-state imaging device 58 is driven by a driving pulse input from the TG 78, photoelectrically converts an optical image formed on the imaging surface 58a via the objective optical system 50, and outputs it as an imaging signal.

  A large number of pixels are arranged in a matrix on the imaging surface 58a of the solid-state imaging element 58, and a photosensor (photoelectric conversion element) is provided for each pixel. Light incident on the imaging surface 58a of the solid-state imaging device 58 is accumulated as a charge in the photosensor of each pixel. The signal charge amount accumulated in the photosensor of each pixel is sequentially read out as a pixel signal by scanning in the vertical and horizontal directions by a vertical scanning circuit and a horizontal scanning circuit (both not shown), and a predetermined frame rate is obtained. Is output.

  Although not shown, the solid-state image sensor 58 is a solid-state image sensor of a single plate color imaging system provided with a color filter composed of a plurality of color segments (for example, a primary color filter with a Bayer array).

  The configuration of a signal readout circuit that reads out the accumulated charge of each photosensor of the solid-state imaging device 58 as an imaging signal is well known, and a general configuration such as a 3-transistor configuration or a 4-transistor configuration can be applied. There is no explanation here.

  The AFE 72 includes a correlated double sampling (CDS) circuit, an automatic gain circuit (AGC), and an A / D converter. The CDS circuit performs correlated double sampling processing on the imaging signal output from the solid-state imaging device 58 to remove reset noise and amplifier noise generated in the solid-state imaging device 58.

  The AGC amplifies the image signal from which noise has been removed by the CDS circuit with a gain (amplification factor) designated by the CPU 80. The A / D converter converts the imaging signal amplified by the AGC into a digital signal having a predetermined number of bits and outputs the digital signal. An imaging signal (digital imaging signal) that is digitized and output by the AFE 72 is input to the processor device 14 through the signal line 66.

  The processor device 14 includes a CPU 82, a ROM 84, a RAM 85, an image processing circuit (DSP) 86, and a display control circuit 88.

  The CPU 82 controls each part in the processor device 14 and controls the entire endoscope system 10 in an integrated manner. The ROM 84 stores various programs and control data for controlling the operation of the processor device 14. The RAM 85 temporarily stores programs executed by the CPU 82 and data.

  The DSP 86 performs color interpolation, color separation, color balance adjustment, gamma correction, image enhancement processing, and the like on the imaging signal input from the AFE 72 under the control of the CPU 82 to generate image data.

  The image data output from the DSP 86 is input to the display control circuit 88, and the display control circuit 88 converts the image data input from the DSP 86 into a signal format corresponding to the monitor 38 and displays it on the screen of the monitor 38.

  The operation unit 90 of the processor device 14 is provided with a mode switching button for selecting or switching the operation mode of the solid-state imaging device 58, and various buttons for receiving other user instruction inputs.

  The light source device 16 includes a main light source 100, a main light source driving circuit 101, an auxiliary light source 102, an auxiliary light source driving circuit 103, a CPU 104, and a multiplexing unit 105. The CPU 104 communicates with the CPU 82 of the processor device 14 and controls the main light source driving circuit 101.

  The auxiliary light source driving circuit 103 performs light emission control of the auxiliary light source 102 based on the main light emission amount of the main light source 100 by the main light source driving circuit 101 instructed by the CPU so that the light emission amount of the auxiliary light source 102 becomes an auxiliary light emission amount described later. Do. The combining unit 105 combines the emitted lights of the main light source 100 and the auxiliary light source 102 and outputs the combined light to the incident end 120 b of the light guide 120. In the present embodiment, since the auxiliary light emission amount is controlled by the main light emission amount according to the CPU instruction, there is no control response delay, and stable color control is possible.

  In the present embodiment, the main light source 100 is a laser diode that emits a blue laser having a wavelength of 445 nm. The main light source 100 is pulse-driven by the main light source driving circuit 101 to control the light emission amount. In the present embodiment, the auxiliary light source 102 is a laser diode that emits a blue laser having a wavelength of 405 nm, and the auxiliary light source driving circuit 103 drives the pulse to control the light emission amount. Blue light having a wavelength of 405 nm is used for special light observation.

  As described above, the phosphor 53 is provided between the emission end 120a of the light guide 120 and the front end illumination window 42 of the electronic endoscope 12. The blue laser light that has passed through the light guide 120 is irradiated onto the phosphor 53 to bring the phosphor 53 into an excited state, and part of the phosphor 53 is transmitted through the phosphor 53 and emitted from the illumination window 42 as blue light.

  The phosphor 53 is excited by blue laser light and emits a wide range of light (yellow as a color) from the wavelength range per blue / green boundary to the red wavelength range in terms of the wavelength band of light. The yellow light and the blue light transmitted through the phosphor 53 (including part of the blue light emitted from the phosphor 53) are mixed to become white light, and the subject is illuminated through the illumination window 42.

  The phosphor 53 mainly emits yellow light and transmits blue light having a wavelength of 445 nm when irradiated with blue laser light having a wavelength of 445 nm. However, most of the phosphor 53 receives blue light having a wavelength of 405 nm. It has a transparent property.

  That is, by controlling the mixing ratio of blue laser light having a wavelength of 445 nm and blue laser light having a wavelength of 405 nm, the ratio of blue light transmitted through the phosphor 53 and yellow light emitted from the phosphor 53 is controlled. Is possible.

  The reflected light from the subject (affected part) illuminated with white light including red (R) light, blue (B) light, and green (G) light is reflected by a solid-state imaging device 58 equipped with color filters of three primary colors of RGB. By receiving light, a color image of the subject is reproduced.

  When the inside of the body cavity is observed with the endoscope system 10 configured as described above, the electronic endoscope 12, the processor device 14, the light source device 16, and the monitor 38 are turned on, and the electronic internal The insertion part 20 of the endoscope 12 is inserted into the body cavity, and the image in the body cavity imaged by the solid-state imaging device 58 is observed on the monitor 38 while illuminating the body cavity with the illumination light from the light source device 16. .

  The CPU 14 determines whether or not the light amount control of the illumination light is to be performed from the captured image signal of the solid-state image sensor 58, and issues a command to the main light source drive circuit 101 when performing the light amount control. Upon receiving an instruction from the CPU, the main light source driving circuit 101 controls the light emission amount of the main light source 100. The phosphor 53 that has received the blue laser light (wavelength 445 nm) emitted from the main light source 100 emits yellow light (green light G is + red R) corresponding to the laser light quantity, and the incident blue wavelength of 445 nm. Transmits the required proportion of blue light in the light.

  In the case of the fluorescent material 53 and the main light source 100 having the characteristics illustrated in FIG. 8, the transmitted blue light having a wavelength of 445 nm increases as the amount of emitted light increases, that is, as the brightness increases, the proportion of blue light transmitted through the fluorescent material 53 increases. B / G increases.

  That is, when the light emission amount of the main light source 100 is increased to the brightness of the point B position with respect to the reference point position (point A position) in FIG. 8, the ratio of R / G is the same as the point A position. On the other hand, B / G rises and the observed image becomes a bluish image. As described above, when B / G changes, the color of the observation image changes, and in particular, it may hinder high-precision surface blood vessel observation.

  Therefore, in the present embodiment, the brightness at the point A is determined using blue laser light obtained by mixing the blue laser light from the main light source 100 and the blue laser light from the auxiliary light source 102 at a predetermined ratio.

  Then, when the amount of light emitted from the main light source 100 is increased to make the illumination light brighter and the brightness at the point B position is increased, the wavelength of the blue laser beam having a wavelength of 445 nm is increased by the amount that is increased. The amount of light emitted from the auxiliary light source 102 having a wavelength of 405 nm is reduced, and control is performed so that the blue light transmitted through the phosphor 53 is the same as the blue light at the reference position A (blue light transmitted through the phosphor 53).

  FIG. 5 is a graph showing an example of the relationship between the light emission amount of the main light source 100 (wavelength 445 nm) and the light emission amount of the auxiliary light source 102 (wavelength 405 nm). When the light emission amount of the main light source 100 (the light emission amount instructed by the CPU 82) is increased, the light emission amount ratio of the auxiliary light source 102 is reduced, and control is performed so that the proportion of the blue light included in the illumination light becomes constant. In the drawing, L represents the light emission amount of each wavelength, a is the slope of the corrected light emission amount ratio (405), and b is the intercept. Thereby, even if the light emission amount control of the main light source 100 is performed to control the intensity of the illumination light, the color change of the observation image is eliminated, and the surface blood vessel observation with high accuracy is possible.

  Referring to the configuration of FIG. 4, when the main light source driving circuit 101 increases the light emission amount of the main light source 100, the auxiliary light source drive circuit 103 decreases the light emission amount ratio of the auxiliary light source 102 and reduces the light emission amount of the main light source 100. When it is decreased, the light emission amount ratio of the auxiliary light source 102 is increased. In the configuration of FIG. 4, the auxiliary light source driving circuit 103 receives the driving amount of the main light source driving circuit 101 and controls the light emission amount of the auxiliary light source 102. However, the auxiliary light source driving circuit 103 also receives an instruction from the CPU 104. It is good also as a structure driven by.

  It can be determined in advance how to control the light emission ratio of the main light source 100 and the auxiliary light source 102 with respect to the characteristics of the phosphor 53. In other words, the characteristics illustrated in FIG. 8 can be measured in advance. Therefore, if this characteristic data is stored as table data in the ROM 84 of FIG. 4, the light emission amount control of illumination light is arbitrarily performed. However, it is possible to always obtain an observation image with no change in color.

  FIG. 6 is a block diagram of the control system of the endoscope system according to another embodiment of the present invention. A difference from the embodiment of FIG. 4 is a light source device 16. In the embodiment of FIG. 4, the phosphor 53 is used. However, in this embodiment, the phosphor light source 53 is used as the light source device 16 without using the phosphor 53.

  The light source device 16 of this embodiment includes an R light emitting LED 100r, a G light emitting LED 100g, and a B light emitting LED 100b as light sources, and light source drive circuits 112r, 112g, and 112b that drive the light sources 100r, 100g, and 100b, respectively. A CPU 114 that outputs a control command to the light source driving circuits 112r, 112g, and 112b, and a multiplexing unit 115 that multiplexes the light emitted from each of the light sources 100r, 100g, and 100b and enters the incident end 120b of the light guide 120. Configured. The CPU 114 communicates with the CPU 82 of the processor device 14 and controls the light source driving circuits 112r, 112g, and 112b.

  In the present embodiment, the light emitting LEDs 100r, 100g, and 100b are used as the light source. However, laser diodes that emit each color may be used. The light intensity of these light sources 100r, 100g, and 100b is controlled by the light source driving circuits 112r, 112g, and 112b.

  The light combined by the multiplexing unit 115 is introduced into the incident end 120b of the light guide 120 configured by bundling a plurality of optical fibers as subject illumination light, and is directed from the emission end 120a through the illumination window 42 toward the subject. Are emitted.

  The reflected light from the subject (affected part) illuminated with white light including red (R) light, blue (B) light, and green (G) light is reflected by a solid-state imaging device 58 equipped with color filters of three primary colors of RGB. By receiving light, a color image of the subject is reproduced.

  As described with reference to FIG. 7, the brightness of the illumination light is controlled when the observation image is captured by moving the distal end portion of the electronic endoscope 12 away from the affected area, and when the observation image is captured close to the affected area. The brightness of the illumination light is the same as in the embodiment of FIG. 4, but can be determined from the captured image signal of the solid-state image sensor 58. When the observation image becomes darker than the predetermined brightness, the light emission amount of the illumination light is increased. When the observation image becomes brighter than the predetermined brightness, the light emission amount of the illumination light is lowered to darken the observation image.

  However, when the energization amount of the light emitting LEDs 100r, 100g, and 100b is controlled to increase or decrease, the individual difference between the light emitting LEDs 100r, 100g, and 100b changes, and as described with reference to FIG. 8, the R light and G light included in the illumination light. , The ratio of B light may change. In this case, the color of the observation image changes or B / G increases, making it unsuitable for superficial blood vessel observation.

  Therefore, in the present embodiment, the energization amount to each of the light sources 100r, 100g, and 100b is controlled so that the color does not change, so that B / G and R / G are always constant, for example, in FIG. The light source control is performed so that the B / G and R / G values are the same as the B / G and R / G at the A point position, and the color of the observation image is the same as the color at the A point position. Do.

  Note that the light source that combines the embodiment of FIG. 4 and the embodiment of FIG. 6 may be used. That is, a light source that emits light having a wavelength of 445 nm may be used as the blue (B) light source 100b in FIG. 6, and a light source that emits special light having a wavelength of 405 nm may be provided in the light source device 16 as a fourth light source.

  In the above-described embodiment, the description has been made based on the characteristics illustrated in FIG. 8. However, when the illumination light is increased, which color light quantity increases or decreases with respect to which color light quantity depends on individual light source differences. The invention is not limited to the characteristics shown in FIG. It is possible to check in advance what kind of change in the amount of light of each color occurs when the illumination light is strengthened. If the checked data is stored as table data in the ROM 84, the CPU 82 instructs the CPU 114 to perform an appropriate light source control instruction. The illumination light always matching the color of the reference position can be generated.

  Here, for example, it is not necessary to store data at all points on the horizontal axis in FIG. 8 as table data, but data at discrete specific positions (in the example of FIG. 8, brightness 50, 100, 150, 200,... Data between these positions) is held, and the data between them may be obtained by interpolation calculation.

  Although the table data has been described as being provided in the ROM 84, the individual difference information of the electronic endoscope 12 is stored in a ROM (not shown) in the CPU 80 of the electronic endoscope 12 instead of the main body side. When the electronic endoscope 12 is connected to the main body devices 14 and 16, if the table data is transferred from the CPU 80 to the CPU 82, control combined with the electronic endoscope 12 when the electronic endoscope 12 is replaced. Is possible.

In the endoscope system and the driving method thereof according to the embodiments described above, a solid-state imaging device is mounted on the distal end portion, and an illuminating unit is provided adjacent to the solid-state imaging device, and the distal end portion is disposed in the body cavity of the subject. An electronic endoscope that illuminates a subject in the body cavity with illumination light emitted from the illuminating unit and captures an image of the subject with the solid-state imaging device,
An endoscope system including an illumination unit that generates the illumination light obtained by mixing the three primary color lights of red light, green light, and blue light and emits the light from the illumination unit to the subject, and a driving method thereof.
When the intensity of the illumination light is changed, among the colors of the red light, the green light, and the blue light, the intensity of the illumination light of the light amount that is smaller than the light amount of the other color is increased, or the light amount of the other color is changed. On the other hand, it is characterized in that the illumination light intensity of a color with a large amount of light is lowered.

The illuminating means of the endoscope system and the driving method thereof according to the embodiment includes a main light source that emits light in a first wavelength region of a predetermined color of any one of the red light, green light, and blue light, and the main light source. A phosphor that absorbs light from the light source and emits mixed light of the remaining two colors and transmits light from the main light source that has not been absorbed; and has the same color as the light from the main light source and the first wavelength An auxiliary light source that emits light having a second wavelength range different from that of the region and emitting light of the phosphor, or at least one of the efficiency of transmitting through the phosphor,
When the light intensity of the first wavelength range emitted from the phosphor is increased by changing the light emission intensity of the main light source, the light emission intensity ratio of the auxiliary light source is decreased and the light emission intensity of the main light source is changed. When the ratio of the light in the first wavelength range emitted from the phosphor decreases, the ratio of the predetermined color of light emitted from the phosphor to other colors is increased by increasing the emission intensity ratio of the auxiliary light source. It is characterized by performing control to keep the constant.

  In addition, the endoscope system and the driving method thereof according to the embodiment control the excitation current of the auxiliary light source in accordance with the excitation current of the main light source, and the ratio of the predetermined color light emitted from the phosphor to other colors It is characterized by keeping constant.

  In the endoscope system and the driving method thereof according to the embodiment, the light in the first wavelength range is light having a wavelength of 445 nm, and the light in the second wavelength range is light having a wavelength of 405 nm.

  In addition, the endoscope system and the driving method thereof according to the embodiment hold the increase / decrease data of the light in the first wavelength range emitted from the phosphor when the emission intensity of the main light source is changed in a memory. The emission intensity of the auxiliary light source is controlled based on the stored data in the memory.

In addition, the illumination unit of the endoscope system and the driving method thereof according to the embodiment includes a first light source that emits the red light, a second light source that emits the green light, and a first light source that emits the blue light. 3 light sources,
When the intensity of the illumination light is increased by increasing the emission intensity of each of the first, second, and third light sources, the amount of light of each color of the red light, green light, and blue light is less than that of the other colors. The illumination light is emitted by increasing the light emission intensity of the light source that emits a color of a certain amount above the light emission intensity of the light source that emits light of another color, and decreasing the light emission intensity of each of the first, second, and third light sources. The light source emits light of another color when the intensity of the light source emits light of a light amount that is larger than the light amount of the other color among the colors of red light, green light, and blue light when the intensity of the light source is reduced The mixing ratio of red light, green light and blue light contained in the illumination light is kept constant.

  According to the embodiments described above, the color of the observation image does not change even when the endoscope tip is photographed close to or away from the main subject, and an easy-to-see observation image without discomfort is provided. It becomes possible to do.

  The endoscope system according to the present invention is useful as an endoscope system capable of providing an easy-to-see observation image and capable of capturing a high-quality image because there is no color change between an image close to and far from an object.

DESCRIPTION OF SYMBOLS 10 Endoscope system 12 Electronic endoscope 14 Processor apparatus 16 Light source apparatus 26 Tip part 26a Tip part tip surface 40 Observation window 42 Illumination window 53 Phosphor 54 Imaging element chip 58 Solid-state imaging element 100 Main light source (wavelength 445nm)
100r R light emitting LED
100g G light emitting LED
100b B light emitting LED
101 Main light source drive circuit 102 Auxiliary light source (wavelength 405 nm: special light observation light source)
103 Auxiliary light source driving circuit 80, 82, 104, 114 CPU
105, 115 Multiplexing unit 120 Light guide 120a Light guide exit end 120b Light guide entrance end

Claims (4)

An electronic endoscope in which an illumination window for illuminating the subject with illumination light is provided at the distal end portion, and a solid-state imaging device that receives light from the subject is mounted on the distal end portion;
A main light source that emits blue light in the first wavelength range and an auxiliary light source that emits blue light in a second wavelength range different from the first wavelength range and is used for special light observation, each having a different wavelength A plurality of light sources that emit light in a region, a light source drive circuit that drives the plurality of light sources, and a light source control unit that controls the light source drive circuit, and the light emitted from the light source is transmitted to the electronic endoscope A light source device to be introduced;
A phosphor having a property of absorbing light from the main light source to emit mixed light of red light and green light and transmitting almost the light from the auxiliary light source, and
The light source control unit turns on the main light source and the auxiliary light source during special light observation, and irradiates the subject with illumination light including blue light and light emitted from the phosphor. When changing the light emission intensity of the main light source by controlling the light intensity of the auxiliary light source, the light intensity of the red component of the illumination light from the illumination window irradiated on the subject is changed to R, the green component An endoscope system in which B / G and R / G are constant when G is G and B is B. The endoscope system according to claim 1,
An endoscope system in which the light in the first wavelength region is light having a wavelength of 445 nm, and the light in the second wavelength region is light having a wavelength of 405 nm. An electronic endoscope in which an illumination window for illuminating the subject with illumination light is provided at the distal end portion, and a solid-state imaging device that receives light from the subject is mounted on the distal end portion;
A main light source that emits blue light in the first wavelength range and an auxiliary light source that emits blue light in a second wavelength range different from the first wavelength range and is used for special light observation, each having a different wavelength A plurality of light sources that emit light in a region, a light source drive circuit that drives the plurality of light sources, and a light source control unit that controls the light source drive circuit, and the light emitted from the light source is transmitted to the electronic endoscope A light source device to be introduced;
Emits mixed light of red light and green light by absorbing light from the main light source, there in operation method of the endoscope system and a phosphor having a property of hardly transmitting the light from the auxiliary light source And
Upon the light source control section, at the time of special light observation, and turns on the auxiliary light source and said main light source, emits the illumination light including the light emitted by the blue light and the phosphor for illuminating said object, When the light source drive circuit is controlled to change the light emission intensity of the main light source, the light emission intensity of the auxiliary light source is changed to change the amount of red component of the illumination light from the illumination window irradiated to the subject. An operation method of the endoscope system in which B / G and R / G are respectively constant when R and G are G and B are B. An operation method of the endoscope system according to claim 3,
The operation method of the endoscope system, wherein the light in the first wavelength region is light having a wavelength of 445 nm, and the light in the second wavelength region is light having a wavelength of 405 nm.

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