WO2017109814A1

WO2017109814A1 - Light scanning observation device

Info

Publication number: WO2017109814A1
Application number: PCT/JP2015/006359
Authority: WO
Inventors: 森　健
Original assignee: オリンパス株式会社
Priority date: 2015-12-21
Filing date: 2015-12-21
Publication date: 2017-06-29

Abstract

This light scanning observation device 10 includes: light sources 33R, 33G, 33B of different colors; a light emitting timing control unit 32; an illumination optical fiber 11 that emits light from the light sources from a distal end onto a subject 100; a drive unit 21 that helically drives the distal end of the illumination optical fiber 11; a light detector 35 that converts light obtained when the subject is irradiated with the light into an electrical signal; and a signal processing unit 37 that generates an image signal on the basis of the electrical signal. The light emitting timing control unit 32 controls the light emitting timings of the light sources 33R, 33G, 33B so that an irradiation density per unit angle in a central region of helical scan is less than an irradiation density per unit angle in a peripheral region thereof and so that an irradiation density of light of at least one color is different from the irradiation densities of light of the other colors .

Description

Optical scanning observation device

The present invention relates to a scanning observation apparatus that performs observation by scanning light on an object and detecting light obtained by irradiation with the light.

The tip of the fiber is vibrated so as to draw a spiral trajectory (a spiral trajectory), and the illumination light emitted from the fiber is irradiated so as to form a spot on the observation target, and the irradiation position is scanned. There is known an optical scanning observation apparatus that detects signal light such as transmitted light, reflected light, or fluorescence obtained from an observation object and converts it into an electrical signal by a photoelectric conversion means to generate image data. (For example, refer to Patent Document 1).

In such an apparatus, the tip of the fiber is usually vibrated in the vicinity of the resonance frequency, and the amplitude is temporally changed between 0 and the maximum value by scanning one frame. Therefore, while the angular velocity of the spiral trajectory is approximately constant, the scanning speed on the observation object is slow in the vicinity of the scanning center having a small amplitude, and the distance from the scanning center increases, that is, the peripheral portion of the acquired image. Scanning speed increases. For this reason, when illumination light irradiation and sampling are performed at a fixed frequency, illumination light irradiation spots are dense in the vicinity of the scanning center and sparse in the outer periphery. In particular, when a plurality of irradiation spots in the vicinity of the scanning center are assigned to the same display coordinates of the generated image, there is a waste of discarding part of the overlapping image data. For this reason, in Patent Document 1, the detection timing of the image signal is adjusted such that unnecessary irradiation spots are thinned with light so that the illumination light irradiation density is substantially constant over the entire scanning region.

JP 2013-121455 A

However, the invention disclosed in Patent Document 1 is not limited to observation of an endoscopic image when a monochromatic light source is used, and does not describe a case of acquiring a color image. On the other hand, in order to obtain a color image with an optical scanning observation device, light sources of different colors such as red (R), green (G), and blue (B) are prepared, and pulsed light from these light sources is used. A method of irradiating the observation target while sequentially switching and detecting the obtained reflected light as image data corresponding to each color is conceivable. When the adjustment of the detection timing of the image signal based on Patent Document 1 is applied to such a method, it is possible to suppress the emission of unnecessary illumination light to some extent.

However, such a method is not a suitable method for acquiring a color image because illumination light of different colors is irradiated to the scanning region at a uniform frequency. For example, when an image is displayed with three primary colors of red, green, and blue, it is known that even if thinning blue which has little contribution to luminance is thinned, the influence on the image is small. However, the emission timing for each color is not controlled. For this reason, even if the technique of Patent Document 1 is adopted in a color scanning observation apparatus, it is not optimized for color image observation, and wasteful power is consumed.

Therefore, an object of the present invention made by paying attention to these points is to provide a scanning observation apparatus that is suitable for displaying a color image and suppressing the power consumption by reducing the number of light emission times of the light source.

The invention of an optical scanning observation apparatus that achieves the above object is as follows.
A light source that selectively emits light of different colors;
A light emission timing control unit for controlling the light emission timing of the light source for each color of light emitted from the light source;
A fiber that guides light from the light source and emits the light from a tip portion that is swingably supported;
A drive unit that vibrates and drives the tip of the fiber in a spiral manner;
An optical system for irradiating the light emitted from the fiber toward the object;
A light detection unit that detects light obtained from the object by the light irradiation and converts the light into an electrical signal;
A signal processing unit that generates an image signal based on an electrical signal from the light detection unit,
The light emission timing control unit is configured such that an irradiation density of light emitted from the fiber per unit angle in a central region including a center of a spiral locus on the object is a unit in an outer peripheral region around the central region. The light emission timing of the light source is controlled so that the irradiation density of light of at least one of the plurality of different colors is different from the irradiation density of light of other colors, which is smaller than the irradiation density per angle. It is a feature.

Preferably, the light emission timing control unit increases the irradiation density of the light emitted from the fiber per unit angle from the center of the spiral trajectory toward the outside during irradiation of the central region. During the irradiation of the outer peripheral region, the light emission timing of the light source is controlled so that the irradiation density of the light emitted from the fiber per unit angle is substantially constant.

Further, the light emission timing control unit controls the light source so that a light emission frequency ratio of light having a high contribution to image quality among the plurality of different colors is higher than a light emission frequency ratio of other colors. It is preferable.

More preferably, the light emission timing control unit emits light from the light source so as to shift the irradiation position on the object of light having a high light emission frequency ratio in the circumferential direction of the spiral scan for each turn. Control timing.

In addition, the light emission timing control unit may emit light from the light source at a higher irradiation density than the irradiation density of the central region and the outer peripheral region with respect to the designated region set on the central region and / or the outer peripheral region. You may make it control the light emission timing of the said light source so that it may irradiate.

According to the present invention, the emission density of the light emitted from the fiber per unit angle in the central region including the center of the spiral locus on the object is determined by the light emission timing control unit is the outer peripheral region around the central region. The light emission timing of the light source is controlled so that the irradiation density of light of at least one of a plurality of different colors is different from the irradiation density of light of other colors. It is possible to provide an optical scanning observation apparatus that is suitable for displaying a color image and has reduced power consumption by reducing the number of light emission times of a light source.

1 is a block diagram illustrating a schematic configuration of an optical scanning endoscope apparatus that is an example of an optical scanning observation apparatus according to a first embodiment. FIG. FIG. 2 is an overview diagram schematically showing a scope of the optical scanning endoscope of FIG. 1. It is sectional drawing of the front-end | tip part of the scope of FIG. It is a figure which shows the actuator of the optical scanning endoscope apparatus and the rocking | fluctuation part of the optical fiber for illumination, FIG. 4 (a) is a side view, FIG.4 (b) is AA sectional drawing of Fig.4 (a). It is. It is a figure which shows distribution of the irradiation spot for every color on a target object. It is a figure which shows distribution of the irradiation spot for every color on the target object which concerns on 2nd Embodiment. It is a figure which shows distribution of the irradiation spot for every color on the target object which concerns on 3rd Embodiment.

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

(First embodiment)
FIG. 1 is a block diagram illustrating a schematic configuration of an optical scanning endoscope apparatus which is an example of an optical scanning observation apparatus according to the first embodiment. The optical scanning endoscope apparatus 10 includes a scope 20, a control device main body 30, and a display 40.

The control device main body 30 includes a control unit 31 that controls the entire optical scanning endoscope device 10, a light emission timing control unit 32,

lasers

33R, 33G, and 33B, and a coupler 34. The light emission timing control unit 32 includes three

lasers

33R, 33G that emit laser beams of three primary colors of red (R), green (G), and blue (B), respectively, according to the light emission timing table 32a transmitted by the control unit 31. The light emission timing of 33B is controlled. In the light emission timing table 32a, the light emission timing from the start of scanning of each frame is stored for each

color laser

33R, 33G, 33B, and the light emission timing control unit 32 performs the laser 33R of the color specified in the light emission timing table 32a. , 33G, 33B are made to emit light at the designated timing in sequence. The light emission timing table 32 a can be stored in advance as data in a memory in the control unit 31 in order to obtain an illumination light irradiation pattern determined on the object 100. However, the control unit 31 calculates the emission timing of each of the

lasers

33R, 33G, and 33B in accordance with the observation conditions of the object 100 such as the required resolution, the light reflection and absorption characteristics of the object 100, and the like. It can also be.

As the

lasers

33R, 33G, and 33B, for example, a DPSS laser (semiconductor excitation solid-state laser) or a laser diode can be used. The paths of the laser beams emitted from the

lasers

33R, 33G, and 33B are coupled by the coupler 34 to the illumination optical fiber 11 that is the same single mode fiber. Of course, the configuration of the light source of the optical scanning endoscope apparatus 10 is not limited to this, and a plurality of other light sources may be used. The

lasers

33R, 33G, and 33B and the coupler 34 may be housed in a separate housing from the control device main body 30 that is connected to the control device main body 30 by a signal line.

The illumination optical fiber 11 is connected to the distal end portion of the scope 20, and light incident on the illumination optical fiber 11 from the coupler 34 is guided to the distal end portion of the scope 20 and directed toward the object 100 as illumination light. Irradiated. At that time, the actuator 21 (driving unit) is driven to vibrate, so that the illumination light emitted from the illumination optical fiber 11 scans on the observation surface of the object 100 so as to draw a spiral trajectory. The actuator 21 is controlled from the control unit 31 via the actuator driver 38 of the control device main body 30. Signal light such as reflected light, scattered light, and fluorescence obtained from the object 100 by irradiation of illumination light is received at the tips of a plurality of detection optical fibers 12 constituted by multimode fibers, and passes through the scope 20. The light is guided to the control device main body 30.

The control device main body 30 further includes a photodetector 35 for processing signal light, an ADC (analog-digital converter) 36, and a signal processing unit 37. The photodetector 35 includes a photodiode or the like, and converts the signal light guided by the detection optical fiber 12 into an electrical signal. The output of the photodetector 35 is offset-corrected, converted to a digital signal by the ADC 36, and output to the signal processing unit 37. The control unit 31 calculates information on the scanning position on the scanning path from information such as the start time, amplitude, and phase of the oscillating voltage applied by the actuator driver 38 and passes the information to the signal processing unit 37. Thereby, the output signal from the photodetector 35 is associated with the scanning position information. Note that the control unit 31 may hold the scanning position information calculated in advance as a table. The signal processing unit 37 synchronizes the signals of each wavelength output from the ADC 36 in a time division manner, performs necessary image processing such as interpolation processing, enhancement processing, and γ processing to generate an image of the object 100, and displays 40 To display.

In each process described above, the control unit 31 synchronously controls the light emission timing control unit 32, the photodetector 35, the actuator driver 38, and the signal processing unit 37.

FIG. 2 is an overview diagram schematically showing the scope 20. The scope 20 includes an operation unit 22 and an insertion unit 23. The operation unit 22 is connected to the illumination optical fiber 11, the detection optical fiber 12, and the wiring cable 13 from the control device main body 30. The illumination optical fiber 11, the detection optical fiber 12, and the wiring cable 13 pass through the insertion portion 23 and are guided to the distal end portion 24 of the insertion portion 23 (portion in the broken line portion in FIG. 2).

FIG. 3 is an enlarged cross-sectional view showing the distal end portion 24 of the insertion portion 23 of the scope 20 of FIG. The tip 24 includes the actuator 21,

projection lenses

25a and 25b, the illumination optical fiber 11 passing through the center, and the detection optical fiber 12 passing through the outer periphery.

The actuator 21 includes an actuator tube 27 fixed inside the insertion portion 23 of the scope 20 by a mounting ring 26, a fiber holding member 29 and piezoelectric elements 28a to 28d disposed in the actuator tube 27 (FIG. 4A). And (b)). The illuminating optical fiber 11 is supported by a fiber holding member 29, and a fixed end 11a supported by the fiber holding member 29 to a tip end portion 11c constitute a swinging portion 11b that is swingably supported. On the other hand, the detection optical fiber 12 is disposed so as to pass through the outer peripheral portion of the insertion portion 23 and extends to the distal end of the distal end portion 24. Further, a detection lens (not shown) is provided at the tip of each fiber of the detection optical fiber 12.

Furthermore, the

projection lenses

25a and 25b and the detection lens (not shown) are arranged at the forefront of the tip 24. The

projection lenses

25 a and 25 b are arranged so that the laser light emitted from the distal end portion 11 c of the illumination optical fiber 11 is substantially condensed on the object 100. Therefore, the

projection lenses

25 a and 25 b constitute an optical system that irradiates the light emitted from the illumination optical fiber 11 toward the object 100. In addition, the detection lens captures light, such as light reflected or scattered or refracted by the object 100 or fluorescence, as signal light by the laser light collected on the object 100, and is disposed after the detection lens. It arrange | positions so that it may condense and couple | bond with the optical fiber 12 for detection. The

projection lenses

25a and 25b are not limited to the two-lens configuration, and may be configured by one lens or a plurality of other lenses.

4A is a diagram showing a vibration driving mechanism of the actuator 21 and the swinging portion 11b of the illumination optical fiber 11 of the optical scanning endoscope apparatus 10, and FIG. 4B is a diagram illustrating FIG. FIG. The illumination optical fiber 11 passes through the center of the fiber holding member 29 having a prismatic shape, and is thereby fixed and held by the fiber holding member 29. The four side surfaces of the fiber holding member 29 face the + Y direction and the + X direction and the opposite directions, respectively. The pair of

piezoelectric elements

28a and 28c for driving in the Y direction are fixed in the + Y direction and the −Y direction of the fiber holding member 29, and the pair of

piezoelectric elements

28b and 28d for driving in the X direction in the + X direction and −X direction. Is fixed.

The wiring cable 13 from the actuator driver 38 of the control device main body 30 is connected to each of the piezoelectric elements 28a to 28d.

When the

piezoelectric elements

28b and 28d arranged opposite to each other with the fiber holding member 29 interposed therebetween contract one another, the other contracts, causing the fiber holding member 29 to bend, and repeating this generates vibration in the X direction. It can be tightened. The same applies to the vibration in the Y direction. For example, as the

piezoelectric elements

28b and 28d in the X direction, piezoelectric elements having the same expansion / contraction direction with respect to the polarity of the voltage to be applied are used, and voltages having the same magnitude but opposite polarity are always applied. Similarly, between the

piezoelectric elements

28a and 28c in the Y direction, piezoelectric elements having the same expansion / contraction direction with respect to the polarity of the applied voltage are used, and voltages having the same magnitude in the opposite direction are always applied.

The actuator driver 38 controls the piezoelectric elements 28a to 28d so that the distal end portion 11c of the illumination optical fiber 11 has a spiral trajectory. Specifically, an AC voltage whose amplitude changes from 0 to the maximum value is applied to the X-direction driving

piezoelectric elements

28b and 28d and the Y-direction driving

piezoelectric elements

28a and 28c. The AC voltages are 90 ° out of phase with each other, and the frequency is set in the vicinity of the same resonance frequency. Thus, the laser light emitted from the tip portion 11c sequentially scans the surface of the object 100 so as to draw a spiral locus.

Next, the light emission timings of the

lasers

33R, 33G, and 33B of the respective colors in the present embodiment will be described. FIG. 5 is a diagram showing the distribution of irradiation spots for each color on the object 100. This figure shows the irradiation spot in the range of 90 ° from the scanning center with the lower right vertex as the scanning center O of the spiral scanning. Actually, the illumination light from the

lasers

33R, 33G, and 33B is scanned over 360 ° around the scanning center O. In FIG. 5, black circles indicate red illumination light irradiation spots 50R, white circles indicate green illumination light irradiation spots 50G, and shaded circles indicate blue illumination light irradiation spots 50B. A fan-shaped arc indicated by a solid line indicates a scanning path (the locus of the center of the imaging position when light is emitted from the illumination optical fiber regardless of whether light is emitted).

The irradiation region of the illumination light on the object 100 includes a circular central region 51 including the scanning center O and an outer peripheral region 52 around the central region 51 (in FIG. 5, each 1/4 of the direction 90 ° from the scanning center). (Only the part of is shown). Under the control of the light emission timing control unit 32, the irradiation spots 50R, 50G, and 50B of red, green, and blue by the illumination light emitted from the laser 33R, laser 33G, and laser 33B are scanned while irradiating the outer peripheral region 52. Irradiation density per unit angle per rotation viewed from the center O is substantially constant regardless of the distance from the scanning center O. In particular, in FIG. 5, the irradiation spots 50R, 50G, and 50B are linearly aligned in the radial direction. On the other hand, during irradiation of the central region 51, the irradiation density per unit angle of the irradiation spots 50R, 50G, and 50B for each round of the spiral scanning is smaller than the irradiation density of the outer peripheral region 52. Further, inside the central region 51, the irradiation density per unit angle of the irradiation spots 50R, 50G, and 50B of the respective colors increases from the scanning center O toward the outside. Preferably, the radius of the central region 51 is about 0.1 to 0.5 when the radius of the irradiation region of the illumination light on the object 100 is 1.

Of the irradiation spots 50R, 50G, and 50B, the green irradiation spots 50G are distributed at a density that is approximately twice that of the red and

blue irradiation spots

50R and 50B. That is, the laser 33G that emits green light has a light emission frequency ratio that is approximately twice that of the

lasers

33R and 33B that emit red and blue light. Here, the reason why the irradiation ratio of the green laser 33G is increased is that green contributes more to luminance information than red and blue. The emission order of the

lasers

33R, 33G, and 33B of each color is repeated from blue (B) → green (G) → red (R) → green (G), and irradiation on the object 100 in the outer peripheral region 52 is performed. As shown in FIG. 5, the

spots

50R, 50G, and 50B are arranged such that the irradiation spot 50G for green illumination light is continuously arranged in the radial direction, and the irradiation spot 50R for red illumination light and the irradiation spot 50B for blue illumination light Are set in the light emission timing table 32a so as to be alternately switched every round.

As is well known, human eyes are more involved in image quality because they are more sensitive to green compared to blue and red. Therefore, the resolution of the observation image of the object 100 can be further increased by doubling the irradiation density of the green irradiation spot compared to the case where the irradiation spots of red, blue, and green are evenly arranged. .

As described above, the light emission timing control unit 32 controls the

lasers

33R, 33G, and 33B according to the light emission order and the light emission timing set in the light emission timing table 32a, so that the illumination light is emitted from the central region 51 of the object 100. Since the irradiation density per unit angle of the irradiation spots 50R, 50G, and 50B is reduced, the irradiation spots 50R, 50G, and 50B are concentrated in the vicinity of the scanning center O, and the laser 33R is not performed without unnecessary laser irradiation. , 33G, 33B can be reduced in the number of times of light emission. Further, the irradiation ratio of the green illumination light that is highly involved in the image quality is made higher than the irradiation ratio of the red and blue illumination light, that is, the emission frequency ratio of the green laser 33G is increased between the red and

blue lasers

33R and 33B. Since the ratio is higher than the number of times of light emission, the number of times of irradiation of the

lasers

33R, 33G, and 33B for obtaining the same resolution may be reduced as compared with the case where the three

lasers

33R, 33G, and 33B emit light at an equal ratio. it can. Therefore, it is possible to reduce power consumption due to light emission of the

lasers

33R, 33G, and 33B.

Further, since the irradiation density per unit angle of the illumination light for each round of the spiral scanning is made constant in the outer peripheral region 52, the irradiation spots 50R, 50G, and 50B are regularly arranged in the radiation direction as shown in FIG. Is possible. Therefore, operations such as interpolation processing of missing color components at each pixel position of the image generated by the signal processing unit 37 are facilitated.
Further, in FIG. 5, the light is emitted at a predetermined angle for every turn, but the light may be emitted at a different angle for each turn without synchronizing the scanning of the fiber and the light emission timing.

(Second Embodiment)
FIG. 6 is a diagram showing a distribution of irradiation spots for each color on the object 100 according to the second embodiment. In the second embodiment, the light emission timing table 32a is set so as to irradiate the object 100 with a pattern of

irradiation spots

50R, 50G, and 50B different from the first embodiment. The present embodiment has the same configuration as that of the optical scanning endoscope apparatus 10 according to the first embodiment described with reference to FIGS. 1 to 4 except that data set in the light emission timing table 32a is different. Therefore, the same components are denoted by the same reference numerals, and the description thereof is omitted.

According to the pattern of

irradiation spots

50R, 50G, and 50B shown in FIG. 6, green and red repeats and green and blue repeats are alternately arranged along a spiral scanning locus for each turn. In addition, the repetition of green and red and the repetition of green and blue are switched at a predetermined angular position (not shown) of any one of the spiral trajectories. Further, unlike FIG. 5, the position of the irradiation spot 50G of the color having the highest light emission frequency ratio for each round in the outer peripheral region 52 is shifted in the circumferential direction of the scanning locus. That is, in FIG. 5, the green irradiation spot 50G is linearly aligned in the radial direction in the outer peripheral region 52, but in FIG. 6, the position of the green irradiation spot 50G is shifted in the circumferential direction for each round of spiral scanning. Therefore, the green irradiation spot 50G and the blue or

red irradiation spots

50R and 50B are alternately irradiated in the radiation direction.

As described above, by arranging the irradiation spots 50R, 50G, and 50B on the object 100 in a pattern as shown in FIG. 6, the green irradiation spot is more irradiated with illumination light than in the case of FIG. Evenly arranged within. As a result, when interpolating the green component pixel signals at the positions of the red and

blue irradiation spots

50R and 50B, signals obtained from the four adjacent green irradiation spots 50G can be used. Therefore, compared with the case of the first embodiment of FIG. 5, the accuracy of interpolation is increased, and the resolution can be further increased. In addition, the illumination density of the illumination light can be further reduced with the same resolution, so that power consumption can be reduced.
6 also has a configuration in which light is emitted at a predetermined angle in the same manner as in FIG. 5, but light is emitted at different angles for each turn without synchronizing the fiber scanning and the light emission timing. I do not care.

(Third embodiment)
FIG. 7 is a diagram showing the distribution of irradiation spots for each color on the object according to the third embodiment.
In the third embodiment, in the irradiation pattern of the irradiation spots 50R, 50G, and 50B of the second embodiment, the irradiation density in the designated area 53 is increased, and the resolution of the observation image in the designated area 53 is further increased. is there. In the present embodiment, the interval of the light emission timing corresponding to the light emission of each color in the designated area 53 of the data set in the light emission timing table 32a is set short. Such a designated region 53 can be set for the control unit 31 by using a non-illustrated input device while the user of the optical scanning endoscope apparatus 10 is viewing an observation image displayed on the display 40. can do.

When receiving the input of the designated area 53 from the user, the control unit 31 calculates the data of the light emission timing table 32a for update, sends it to the light emission timing control unit 32, and replaces it with the light emission timing table 32a being observed. . This increases the irradiation density of the irradiation spots 50R, 50G, and 50B for the designated region 53, and enables high-resolution observation. Note that the light emission timing table 32a is not obtained by calculation each time, but some patterns may be prepared in the control unit 31 in advance and selected from them. Since other configurations are the same as those of the optical scanning observation apparatus according to the first embodiment described with reference to FIGS. 1 to 4, the same components are denoted by the same reference numerals, and the description thereof is omitted.

By doing so, it is possible to increase the resolution of the designated area 53 during operation of the optical scanning endoscope apparatus 10, so that it is possible to confirm or save the details of the part that is particularly desired to be observed. Become. Further, the designated region 53 may be partially enlarged and displayed by the signal processing unit 37. In addition, it is not necessary to always increase the resolution of the entire screen, and the illumination density of the illumination light is increased only in necessary areas as necessary, so that power consumption is suppressed compared to the case of always performing high-resolution observation. Can do.

It should be noted that the present invention is not limited to the above embodiment, and many variations or modifications are possible. For example, in each of the above embodiments, the irradiation density per unit angle of the irradiation spot of the illumination light is substantially constant in the outer peripheral area of the object, but the irradiation density per unit angle of the irradiation spot in the outer peripheral area is set as the irradiation direction. It can also be changed according to the position of.

In addition, the light emission timing table data can be set in various ways. For example, the light emission frequency ratio is not limited to the green laser 33G. If the red image is highly involved in the image, the red laser 33R emission frequency ratio is set so that the irradiation density of the red illumination light is increased. It is also possible to increase the ratio of the number of times of light emission of other specific light sources, such as by increasing the ratio of the number of times of light emission of the light source of a specific color. Furthermore, the light source is not limited to the three colors of red, green, and blue, and other combinations of a plurality of colors are possible.

Further, the present invention can be applied not only to an optical scanning endoscope apparatus but also to an optical scanning microscope apparatus. In addition, the drive unit that performs spiral scanning is not limited to an actuator that uses a piezoelectric element. For example, an actuator that includes a permanent magnet and an electromagnetic coil and generates a driving force by an electromagnetic force may be used.

DESCRIPTION OF SYMBOLS 10 Optical scanning endoscope apparatus 11 Illumination optical fiber 11a Fixed end

11b Oscillating part

11c Tip part 12 Detection optical fiber 13 Wiring cable 20 Scope 21 Actuator 22 Operation part 23 Insertion part 24

Tip part

25a, 25b Projection lens 26 Mounting ring 27 Actuator tube 28a to 28d Piezoelectric element 29 Fiber holding member 30 Control device main body 31 Controller 32 Light emission timing controller 32a Light emission table 33R, 33G, 33B Laser 34 Coupler 35 Photo detector 36 ADC
37 Signal processor 38 Actuator driver 40 Display 51 Central area 52 Outer peripheral area 53 Specified area

Claims

A light source that selectively emits light of different colors;
A light emission timing control unit for controlling the light emission timing of the light source for each color of light emitted from the light source;
A fiber that guides light from the light source and emits the light from a tip portion that is swingably supported;
A drive unit that vibrates and drives the tip of the fiber in a spiral manner;
An optical system for irradiating the light emitted from the fiber toward the object;
A light detection unit that detects light obtained from the object by the light irradiation and converts the light into an electrical signal;
A signal processing unit that generates an image signal based on an electrical signal from the light detection unit,
The light emission timing control unit is configured such that an irradiation density of light emitted from the fiber per unit angle in a central region including a center of a spiral locus on the object is a unit in an outer peripheral region around the central region. The light emission timing of the light source is controlled so that the irradiation density of light of at least one of the plurality of different colors is different from the irradiation density of light of other colors, which is smaller than the irradiation density per angle. An optical scanning type observation device.
The light emission timing control unit increases the irradiation density of light emitted from the fiber per unit angle toward the outside from the center of the spiral trajectory while irradiating the central region. 2. The optical scanning type according to claim 1, wherein the light emission timing of the light source is controlled so that an irradiation density of light emitted from the fiber per unit angle is substantially constant during irradiation of the light source. Observation device.
The light emission timing control unit controls the light source so that a light emission number ratio of light having a high contribution to image quality among the plurality of different colors is higher than a light emission number ratio of other colors. The optical scanning observation apparatus according to claim 1, wherein the optical scanning observation apparatus is characterized.
The light emission timing control unit controls the light emission timing of the light source so as to shift the irradiation position on the object of light having a color with a high light emission frequency ratio in the circumferential direction of the spiral scan for each turn. The optical scanning observation apparatus according to any one of claims 1 to 3, wherein
The light emission timing control unit irradiates light from the light source at a higher irradiation density than the irradiation density of the central region and the outer peripheral region with respect to the predetermined region set on the central region and / or the outer peripheral region. The optical scanning observation apparatus according to any one of claims 1 to 4, wherein the light emission timing of the light source is controlled as described above.