JP2020009551A - Light source device - Google Patents

Abstract

To provide a light source device which estimates light volume of each of a plurality of light sources with a more simple structure, and can adjust so that the color of emission light becomes a predetermined color by the estimation result.SOLUTION: A light source device 1 includes: light sources 21, 22 for generating first light and second light; an optical member 30; an optical path integration part 40 for integrating a first optical path and a second optical path; an optical path branch member 50 for branching the first optical path into a first branch optical path and for branching the second optical path into a second branch optical path; a plurality of optical detectors arranged in the first branch optical path and the second branch optical path, and outputting a detection value D according to the first light and the second light; and a light volume control part 80 for controlling at least one of the first light volume of the first light and the second light volume of the second light according to the detection value D.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light source device.

  Conventionally, for example, there is a light source device that outputs output light so that a subject to be imaged by an imaging device can be illuminated. The light source device may change the light amount ratio between the light sources of the respective colors to adjust the output light to a predetermined color.

  For example, in Japanese Patent Application Laid-Open No. 11-201894, a sensor is installed in an optical head, and a spectral output obtained by the sensor is analyzed by a spectral analyzer, and the intensity ratio between light sources does not match a desired one. In this case, an illumination device for an observation optical system that adjusts the output of each light source using a light amount adjustment unit is disclosed.

JP-A-11-201894

  However, in the conventional light source device, in order to adjust the color of the output light to a predetermined color, a device having a complicated structure for analyzing the output light, such as a spectroscopic analyzer, is required, and the manufacturing cost is reduced. It takes.

  Therefore, an object of the present invention is to provide a light source device capable of estimating the light quantity of each of a plurality of light sources with a simple structure and adjusting the color of output light to a predetermined color based on the estimation result. I do.

  A light source device according to one embodiment of the present invention includes a light source that generates first light and second light, and is disposed on a first optical path of the first light and a second optical path of the second light. The first light and the second light are incident, and an optical path integrating unit that integrates the first optical path and the second optical path; and an optical member integrated on the first optical path and the second optical path. An optical path branching member that is arranged on the optical path of the first optical path, splits the first optical path into a first split optical path, and splits the second optical path into a second split optical path, the first split optical path, and the second split optical path. A plurality of photodetectors arranged in two branch optical paths and outputting detection values according to the first light and the second light, and a first light amount of the first light according to the detection values And a light amount control unit that controls at least one of a second light amount of the second light.

  According to the present invention, it is possible to provide a light source device capable of estimating the light quantity of each of a plurality of light sources with a simpler structure and adjusting the color of output light to a predetermined color based on the estimation result. .

It is a block diagram showing an example of a light source device concerning an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of an arrangement of each light source of the light source device according to the embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a configuration of a light detection unit of the light source device according to the embodiment of the present invention. 6 is a flowchart illustrating an example of a light amount control process of the light source device according to the embodiment of the present invention.

  An embodiment of the present invention will be described with reference to the drawings.

(Constitution)
FIG. 1 is a block diagram illustrating an example of a light source device 1 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of the arrangement of each light source of the light source device 1. FIG. 3 is a diagram illustrating an example of the configuration of the light detection unit 60 of the light source device 1.

  As shown in FIG. 1, the light source device 1 outputs the output light Lo to the outside. The light source device 1 includes a drive circuit 10, a light source 20, an optical member 30, an optical path integration unit 40, an optical path branching member 50, a light detection unit 60, a detection circuit 70, and a light amount control unit 80.

  The drive circuit 10 is a circuit that drives the light source 20. The drive circuit 10 is connected to the light source 20 and the light amount control unit 80. The drive circuit 10 outputs drive currents I1, I2, and I3 to the light source 20 according to the instruction signal V input from the light amount control unit 80. When all or part of the drive currents I1, I2, and I3 are indicated, they are referred to as drive currents I.

  As shown in FIG. 2, the light source 20 is a circuit that generates and emits light L. The light source 20 has a light emitting element such as a laser diode. The light source 20 generates light L and emits the light L toward the optical member 30. The light source 20 includes light sources 21, 22, and 23. When all or a part of the light sources 21, 22, and 23 are shown, they are referred to as light sources 20. Each of the light sources 20 is arranged at a different position so that the optical path O is different.

  The light source 21 emits light L1 according to the drive current I1. The light source 22 emits light L2 according to the drive current I2. The light source 23 emits light L3 according to the drive current I3. When indicating all or a part of the light L1, L2, and L3, it is referred to as light L.

  The light L has different frequency bands. For example, light L1 is in a red band, light L2 is in a green band, and light L3 is in a blue band.

  The optical member 30 emits each of the light L incident from each of the light sources 20 to the optical path integrating unit 40. The optical member 30 has a collimator lens 31 and a condenser lens 32.

  The collimator lens 31 is provided in association with each of the light sources 20. Each of the collimator lenses 31 converts each of the light L having a radiation angle, which is incident from each of the light sources 20, into parallel light, and emits the parallel light.

  Each of the light L incident from each of the collimator lenses 31 is incident on a different position on the condenser lens 32. The condenser lens 32 emits the light L to the optical path integrating unit 40 so that each of the light L incident from each of the collimator lenses 31 is collected.

  The optical path integrating unit 40 integrates each of the optical paths O of the light L incident on the incident unit 41 and emits the light L from the emitting unit 42 to the outside. The optical path integrating unit 40 has, for example, a light guide in which the incident unit 41 is provided at one end and the emission unit 42 is provided at the other end.

  An optical path O1 of the light L1 extends from the light source 21 to the incident portion 41. The path from the light source 22 to the entrance 41 is the optical path O2 of the light L2. An optical path O3 of the light L3 extends from the light source 23 to the incident portion 41. When indicating all or a part of the optical paths O1, O2, and O3, it is referred to as an optical path O.

  The optical path branching member 50 is arranged on the optical path O. For example, the optical path branching member 50 has a half mirror that transmits part of the light L and reflects part of the light L. The optical path branching member 50 passes a part of the light L through the optical path O, and branches the optical path O through which a part of the light L passes into a branch optical path Ob. More specifically, the light path branching member 50 passes a part of the light L1 through the branch light path Ob1, a part of the light L2 through the branch light path Ob2, and a part of the light L3 through the branch light path Ob3. When all or some of the branch optical paths Ob1, Ob2, and Ob3 are shown, they are referred to as branch optical paths Ob.

  As shown in FIG. 3, the light detection unit 60 is a circuit that detects the light L and outputs a detection signal S to the detection circuit 70. The light detection unit 60 includes light detectors 61, 62, and 63. Each of the photodetectors 61, 62 and 63 is constituted by a light receiving element such as a photodiode. The light detection unit 60 is disposed on the branch light path Ob so that each of the lights L does not concentrate on any of the light detectors 61, 62, and 63. The photodetector 61 outputs a detection signal s1, the photodetector 62 outputs a detection signal s2, and the photodetector 63 outputs a detection signal s3. When indicating all or part of the detection signals s1, s2, and s3, it is referred to as a detection signal S.

  In the example of FIG. 3, the light detection unit 60 is configured by a photodiode divided into four, and the light detector 64 is provided, but the light detector 64 may not be provided.

  The detection circuit 70 is a circuit that converts the detection signal S into a detection value D and outputs the same to the light amount control unit 80. More specifically, the detection circuit 70 converts the detection signal S input from the light detection unit 60 into detection values d1, d2, and d3 corresponding to each of the detection signals S, and outputs the detection values to the light amount control unit 80. When indicating all or a part of the detection values d1, d2, and d3, it is referred to as a detection value D.

  Note that the detection circuit 70 may perform signal processing such as noise removal of the detection signal S to convert the detection signal S into the detection value D.

  The light amount controller 80 is a circuit that is connected to the drive circuit 10, outputs an instruction signal V to the drive circuit 10, and controls the light source 20. The light quantity control unit 80 has a processor 81 and a memory 82 as a storage unit.

  The processor 81 can execute various programs read from the memory 82, an external storage device, or an external terminal device. The function of the light amount control unit 80 is realized by the processor 81 executing a program. Further, all or a part of the function of the light amount control unit 80 may be configured by a circuit having, for example, an FPGA or an ASIC.

  The memory 82 has a readable and writable storage element such as a flash ROM, for example. The memory 82 stores a program for the light amount control processing unit T, a reference light amount U, and a weight amount W.

  The light amount control processing unit T estimates the light amount P of the light L by the estimation unit Ta, and controls the light source 20 according to the estimation result. The estimating unit Ta calculates the light amount P by an operation based on the weight amount W and the detection value D.

More specifically, as shown in Expression (1), the estimation unit Ta calculates the light amount P by performing a matrix operation on the weight amount W and the detection value D.

  The light amount P is calculated by the estimation unit Ta. The light amount P has light amounts p1, p2, and p3. When indicating all or a part of the light amounts p1, p2, and p3, it is referred to as a light amount P. The light amount P has each of the light amounts P associated with each of the light sources 20. More specifically, the light amount p1 is associated with the light source 21, the light amount p2 is associated with the light source 22, and the light amount p3 is associated with the light source 23.

  When the light amount P is smaller than the reference light amount U, the light amount control processing unit T outputs to the drive circuit 10 an instruction signal V obtained by increasing the instruction light amount by a predetermined amount. On the other hand, when the light amount P is larger than the reference light amount U, the light amount control processing unit T outputs to the drive circuit 10 an instruction signal V in which the instruction light amount is reduced by a predetermined amount.

  The instruction signal V is configured by, for example, a PWM signal that indicates an instruction light amount by a duty. The instruction signal V has instruction signals v1, v2, and v3 associated with each of the light sources 20.

  The initial value of the designated light amount is determined by adjusting in advance so that the output light Lo has a predetermined color.

  The predetermined amount is predetermined so that the speed and accuracy of the color adjustment are favorable. If the predetermined amount is set to be large, the speed of the color adjustment increases and the accuracy decreases. On the other hand, when the predetermined amount is set to be small, the speed of the color adjustment decreases, and the accuracy increases.

  The reference light amounts U have reference light amounts u1, u2, and u3 associated with the respective light sources 20. When indicating all or a part of the reference light amounts u1, u2, and u3, it is referred to as a reference light amount U. Each of the reference light amounts U is predetermined so that output light Lo of a predetermined color and a predetermined output light amount can be output. In the output light Lo, the color changes according to the ratio of the reference light amount U to each other, and the output light amount changes according to the magnitude of the reference light amount U.

  The weight amount W is predetermined based on the light amount P and the detection value D. The weight amount W has components of M rows and N columns, and is configured by a matrix indicating the mutual relationship of the light amounts P. In the example of Expression (1), the weight amount W is a third-order regular matrix.

The weight amount W may be an inverse matrix of the weight matrix A in Expression (2). The weight matrix A is constituted by a third-order regular matrix. Each of the matrix components a11 to a33 in the weight matrix A is calculated by sequentially emitting the light L from each of the light sources 20 and measuring the detection value D.

For example, the light source device 1 drives the light source 21 so that the light L1 having the predetermined light amount p1 is emitted, and stops the light sources 22 and 23. Since the light L2, L3 is not emitted from the light sources 22, 23, the light amounts p2, p3 are zero. When the detection value D is detected by the light detection unit 60 and the detection circuit 70, the matrix components a11, a21, and a31 are calculated by Expressions (3) to (5).
a11 × p1 + a12 × p2 + a13 × p3 = a11 × p1 = d1
a21 × p1 + a22 × p2 + a23 × p3 = a21 × p1 = d2
a31 × p1 + a32 × p2 + a33 × p3 = a31 × p1 = d3
a11 = d1 / p1 (3)
a21 = d2 / p1 (4)
a31 = d3 / p1 (5)

  Similarly, when the light source 22 is driven so that the light L2 having the predetermined light amount p2 is emitted, the light sources 21 and 23 are stopped, and the detection value D is detected, the matrix components a12, a22, and a32 are calculated. When the light source 23 is driven to emit the light L3 having the predetermined light amount p3, the light sources 21 and 22 are stopped, and the detection value D is detected, the matrix components a13, a23, and a33 are calculated.

  The relationship between the calculated weight matrix A having matrix components a11 to a33, the light amount P, and the detection value D is represented by AP = D (Equation (2)).

  The weight amount W is calculated by an operation for obtaining an inverse matrix of the weight matrix A.

  When both sides are deformed, WAP = WD is established. When the left side is further arranged, the relationship between the light amount P, the weight amount W, and the detection value D is represented by P = WD (Equation (1)).

  That is, the light sources 21 and 22 generate the light L1 and the light L2. The optical member 30 is disposed on the optical path O1 of the light L1 and on the optical path O2 of the light L2. The light path integration unit 40 receives the light L1 and the light L2 and integrates the light path O1 and the light path O2. The optical path branching member 50 is disposed on the optical paths O1 and O2, branches the optical path O1 into a branched optical path Ob1, and branches the optical path O2 into a branched optical path Ob2. The plurality of photodetectors 61, 62, and 63 are arranged in the branch optical path Ob1 and the branch optical path Ob2, and output a detection value D according to the light L1 and the light L2. The light amount control unit 80 controls at least one of the light amount p1 of the light L1 and the light amount p2 of the light L2 according to the detection value D.

  Further, the light amount control unit 80 includes an estimating unit Ta that outputs an estimation result by estimating the light amount p1 and the light amount p2 according to the detection value D, and at least one of the light amount p1 and the light amount p2 according to the estimation result. Control. More specifically, the estimation unit Ta outputs an estimation result by estimating the light amount p1 and the light amount p2 by an operation based on the weight amount W and the detection value D, and the light amount control unit 80 outputs the reference light amount U and the estimated light amount At least one of the light amount p1 and the light amount p2 is controlled according to the result. The estimating unit Ta calculates the light amount p1 and the light amount p2 based on the detection value D and the weight amount W. The weight amount W is configured by a matrix indicating the relationship between the detection value D and the light amounts p1 and p2. The estimating unit Ta calculates the light amount L1 and the light amount L2 based on the detected value D using a matrix indicating the relationship between the detected value D and the light amounts L1 and L2.

  The light L1 and the light L2 are laser lights. The light sources 21 and 22 include a first laser light source that generates the light L1 and a second laser light source that generates the light L2. The optical member 30 has a lens that causes the light L1 and the light L2 to enter the optical path integration unit 40. The optical path branching member 50 is a half mirror that transmits part of the light L and reflects part of the light L.

(motion)
The operation of the light source device 1 will be described.

  FIG. 4 is a flowchart illustrating an example of a light amount control process of the light source device 1 according to the embodiment of the present invention.

  The light quantity control unit 80 reads the initial value of the designated light quantity from the memory 82 and outputs an instruction signal V corresponding to the designated light quantity to the drive circuit 10. The drive circuit 10 outputs a drive current I according to the instruction signal V to the light source 20. The light source 20 emits light L.

  Part of the light L passes through the optical path O and is incident on the incident section 41, and is integrated by the optical path integrating section 40. The optical path integration unit 40 outputs the output light Lo from the emission unit 42 to the outside.

  Part of the light L passes through the branch optical path Ob by the optical path branching member 50 and is emitted to the light detection unit 60.

  The light detection unit 60 detects the light L and outputs a detection signal S to the detection circuit 70. The detection circuit 70 converts the detection signal S into a detection value D and outputs the same to the light quantity control unit 80.

  The processor 81 reads the program of the light quantity control processing unit T from the memory 82 and executes it.

  The processor 81 acquires the weight amount W (S11).

  The processor 81 acquires the reference light amount U (S12).

  The processor 81 acquires the detection value D (S13).

  The processor 81 calculates the light amount P based on the detection value D and the weight amount W (S14).

  The processing of S15 to S18 is repeatedly performed for each of the light sources 20. For example, in the first repetition, control processing of the light source 21 is performed based on the reference light amount u1, the light amount p1, and the instruction signal v1, and in the second repetition, the light source 21 is controlled based on the reference light amount u2, the light amount p2, and the instruction signal v2. The control process of the light source 23 is performed based on the reference light amount u3, the light amount p3, and the instruction signal v3 in the third repetition.

  The processor 81 determines whether or not the error in the light amount P calculated in S14 with respect to the reference light amount U exceeds a predetermined error (S15). When the error of the light amount P with respect to the reference light amount U is equal to or smaller than a predetermined error (S15: NO), the process proceeds to S19. On the other hand, when the error of the light amount P with respect to the reference light amount U exceeds a predetermined error (S15: YES), the process proceeds to S16.

  The processor 81 determines whether the reference light amount U is larger than the light amount P (S16). When the reference light amount U is larger than the light amount P (S16: YES), the process proceeds to S17. On the other hand, when the reference light amount U is smaller than the light amount P (S16: NO), the process proceeds to S18.

  In S17, the processor 81 reads the designated light amount from the memory 82, and outputs to the drive circuit 10 an instruction signal V in which the designated light amount is reduced by a predetermined amount. After S17, the process proceeds to S19.

  In S18, the processor 81 reads the designated light amount from the memory 82, and outputs to the drive circuit 10 a designated signal V in which the designated light amount is increased by a predetermined amount.

  The designated light amount changed in S17 and S18 is stored in the memory 82 in preparation for the next use.

  The processor 81 determines whether the control processing of all the light sources 20 has been completed (S19). The processor 81 repeats the processing of S15 to S18 until the control processing of all the light sources 20 ends (S19: NO). When the control process for all the light sources 20 is completed (S19: YES), the process returns to S13, and performs the next light amount control process.

  The processing of S11 to S14 constitutes the estimation processing of the estimation unit Ta.

  The processing of S11 to S19 constitutes the processing of the light amount control processing unit T.

  For example, when the light L1 having the specified light amount is not output due to a manufacturing error or deterioration of the light source 21, the detection value D output by the light detection unit 60 and the detection circuit 70 is determined when the light L1 having the specified light amount is output. Smaller than. The light amount control unit 80 calculates the light amount p1 based on the detection value D by the calculation of the estimating unit Ta, but the light amount p1 is smaller than the reference light amount u1. The light quantity control unit 80 increases the designated light quantity by a predetermined amount, and outputs a designated signal v1 to the drive circuit 10. When the drive circuit 10 also increases the drive current I1 in accordance with the increase in the indicated light amount, the light source 21 increases the output light amount. By repeating the light amount control process, the light amount p1 of the light source 21 is adjusted so as to converge on the reference light amount u1.

  Similarly, the light sources 22 and 23 are also adjusted so that the light amounts p2 and p3 converge on the reference light amounts u2 and u3.

  Accordingly, the light source device 1 is adjusted such that each of the light amounts P estimated by the estimating unit Ta converges on each of the reference light amounts U, and each of the lights L adjusted by each of the light amounts P is transmitted by the optical path integrating unit 40. It is integrated and adjusted so that the color of the output light Lo becomes a predetermined color.

  In the embodiment, the light source device 1 estimates the light amount P of each of the plurality of light sources 21, 22, and 23 with a simpler structure, and adjusts the color of the output light Lo to a predetermined color based on the estimation result. it can.

  In the embodiment, an example has been described in which the instruction signal V is a PWM signal that instructs the drive current I according to the duty, but the instruction signal V is not limited to the PWM signal. The instruction signal V may be, for example, a voltage signal that indicates the drive current I by a voltage value, an information signal that indicates the drive current I by a numerical value, or another signal. .

  In the embodiment, an example in which the light source 20 is driven by current is described, but the light source 20 is not limited to the current drive. The light source 20 may be driven by another method such as a PWM signal.

  In the embodiment, the example in which the light source 20 includes a light emitting element such as a laser diode is described, but the light source 20 is not limited to the laser diode. The light source 20 may have another light emitting element such as an LED, for example.

  In the embodiment, an example in which three light sources 21, 22, and 23 are provided has been described, but the number of light sources is not limited to three. The number of light sources may be two or four or more.

  In the embodiment, an example has been described in which the light L1 is red band light, the light L2 is green band light, and the light L3 is blue band light, but is not limited thereto. For example, one of the lights L may be a narrow band light, a band light of an intermediate color of each color, a wide band light including a plurality of colors, or a white light. Is also good.

  In the embodiment, the light path integrating unit 40 is configured by a light guide, but is not limited thereto. The optical path integrating unit 40 may be configured by an optical system such as a lens, for example.

  In the embodiment, an example in which four photodetectors 61, 62, 63, and 64 are provided has been described, but the number of photodetectors is not limited to four. The number of photodetectors may be two or three, or may be five or more.

  Note that, in the embodiment, an example of the tertiary regular weight matrix W is described. Further, the weight amount W does not have to be a regular matrix or a square matrix. For example, each of the components of the weight amount W is measured according to the measurement result by measuring any one of the drive current I, the light amount P, the detection value D, and the instruction signal V so that the light L of the predetermined color is output. May be determined.

  As long as each step of each procedure in the present embodiment does not violate its nature, the order of execution may be changed, a plurality of steps may be executed simultaneously, or each step may be executed in a different order. Further, all or a part of each step of each procedure in the present embodiment may be realized by hardware.

  The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Light source device 10 Drive circuit 20 Light source 21 Light source 22 Light source 23 Light source 30 Optical member 31 Collimator lens 32 Condensing lens 40 Optical path integration part 41 Incident part 42 Emission part 50 Optical path branching member 60 Light detection part 61 Light detector 62 Light detector 63 photodetector 64 photodetector 70 detection circuit 80 light quantity control unit 81 processor 82 memory D detection value I drive current I1 drive current I2 drive current I3 drive current L light Lo output light L1 light L2 light L3 light O light path O1 light path O2 Optical path O3 Optical path Ob Branch optical path Ob1 Branch optical path Ob2 Branch optical path Ob3 Branch optical path P Light quantity S Detection signal T Light quantity control processing section Ta Estimating section U Reference light quantity V Instruction signal W Weight

Claims (5)

A light source that generates a first light and a second light;
An optical member arranged on a first optical path of the first light and on a second optical path of the second light;
An optical path integration unit that receives the first light and the second light and integrates the first optical path and the second optical path;
An optical path branching member disposed on the first optical path and the second optical path, for branching the first optical path into a first branch optical path, and for branching the second optical path into a second branch optical path; ,
A plurality of photodetectors arranged on the first branch optical path and the second branch optical path and outputting detection values according to the first light and the second light;
A light amount controller that controls at least one of a first light amount of the first light and a second light amount of the second light according to the detection value;
A light source device having: The light amount control unit includes:
An estimating unit that outputs an estimation result by estimating the first light amount and the second light amount according to the detection value;
Controlling at least one of the first light amount and the second light amount according to the estimation result;
The light source device according to claim 1. The first light and the second light are laser light,
The light source includes a first laser light source that generates the first light, and a second laser light source that generates the second light,
The optical member includes a lens that causes the first light and the second light to enter the optical path integration unit,
The optical path branching member is a half mirror that transmits part of the first light and the second light and reflects part of the first light and the second light.
The light source device according to claim 1. It has a storage unit,
The storage unit stores a reference light amount and a weight amount,
The estimating unit outputs the estimation result by estimating the first light amount and the second light amount by a calculation based on the weight amount and the detection value,
The light amount control unit controls at least one of the first light amount and the second light amount according to the reference light amount and the estimation result;
The light source device according to claim 2.   The estimating unit calculates the first light amount and the second light amount based on the detected value using a matrix indicating a relationship between the detected value and the first light amount and the second light amount. The light source device according to claim 2.

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