JP6623711B2 - Inspection device - Google Patents

Description

  The present invention relates to an inspection device, and more particularly, to an inspection device that inspects a wavelength conversion member containing a phosphor.

  2. Description of the Related Art There is known a white light emitting device that emits white light and includes an optical element that emits blue light and a wavelength conversion member containing a phosphor. In this white light emitting device, by irradiating the wavelength conversion member with blue light (excitation light) emitted from the optical element, fluorescence emitted from the phosphor contained in the wavelength conversion member and reflected or transmitted by the wavelength conversion member are reflected. Blue light is mixed to achieve white light emission.

  The wavelength conversion member as described above is formed, for example, by forming a phosphor-containing composition in which a phosphor is dispersed in a base material such as a resin or a ceramic into a sheet shape, and then forming a predetermined material corresponding to an optical element that emits blue light. Although it is manufactured by being cut into shapes, even if manufactured under certain conditions, the concentration of the phosphor contained in the wavelength conversion member and the thickness of the wavelength conversion member may vary, affecting the hue of the white light emitting device. There is.

  In order to suppress such variations, it has been proposed to measure the chromaticity of the wavelength changing member before the white light emitting device is manufactured by assembling the wavelength converting member to the optical element (for example, see Patent Document 1 below). .

JP 2014-79905 A

  Conventionally, the chromaticity of the wavelength changing member is calculated by irradiating the wavelength changing member with excitation light inside the integrating sphere and integrating the excitation light (transmitted light) transmitted through the wavelength changing member and the fluorescence emitted from the wavelength changing member. It is measured by detecting with a spectroscope through a light receiving window provided in the sphere.

  However, when detecting chromaticity using an integrating sphere, it is necessary to bring the wavelength converting member into contact with the port through which the transmitted light and the fluorescent light enter the integrating sphere. There is a problem that it is difficult to measure the in-plane distribution of the degree, or to measure the chromaticity of a large number of wavelength changing members which are cut into small pieces and closely arranged in a grid.

  The present invention has been made in view of the above-described problems, and measures the in-plane distribution of chromaticity of a wavelength conversion member containing a phosphor, or cuts into small pieces and arranges them in close proximity in a lattice shape. It is an object of the present invention to provide an inspection apparatus capable of individually measuring chromaticity of the wavelength changing member.

An inspection apparatus according to the present invention is an inspection apparatus for inspecting a wavelength conversion member containing a phosphor, wherein a light source unit that irradiates the wavelength conversion member with excitation light that is diffused light. And an objective lens that captures the fluorescence emitted from the wavelength conversion member by irradiation of the excitation light and the excitation light transmitted through the wavelength conversion member, and a moving mechanism that moves at least one of the objective lens and the wavelength conversion member. A spectroscope for measuring the spectrum of light captured by the objective lens, wherein the objective lens is located at a plurality of different positions of the wavelength conversion member, and the objective lens has an actual field of view narrower than the irradiation range of the excitation light on the wavelength conversion member . the fluorescence and said actual field of view captures the excitation light transmitted through the spectrometer spectra of the objective lens is taken light emanating from It is intended to be measured.

  In the inspection device of the present invention, it is preferable that the excitation light emitted from the light source unit to the wavelength conversion member is diffused light.

  In the inspection device of the present invention, the moving mechanism may move the wavelength conversion member in a state where the light source unit and the objective lens are stopped.

  In the inspection device of the present invention, the moving mechanism may move the objective lens with the wavelength conversion member stopped. In this case, a light source moving mechanism may be provided to move the light source unit in synchronization with the objective lens.

  In the inspection device of the present invention, the moving mechanism may change the angle of the wavelength conversion member with respect to the optical axis of the objective lens.

  Further, the inspection device of the present invention may include a temperature control unit that controls the temperature of the light source unit. In that case, the temperature control unit may change the temperature of the light source unit to change the wavelength of the excitation light emitted from the light source unit.

  In the inspection device of the present invention, the support may include a transparent holding sheet for fixing the wavelength conversion member by bonding.

  According to the present invention, the in-plane distribution of chromaticity is measured for a wavelength conversion member containing a phosphor, or the chromaticity is individually measured for a large number of wavelength change members that are cut into small pieces and arranged close to each other in a lattice shape. Can be measured.

It is a schematic diagram of an inspection device concerning one embodiment of the present invention. FIG. 2 is a block diagram illustrating a control configuration of the inspection device of FIG. 1.

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

  The inspection apparatus 10 according to the present embodiment is configured such that the chromaticity coordinates of the light emitted from the wavelength conversion member 11 when the wavelength conversion member 11 containing the phosphor is irradiated with the excitation light are converted into a plurality of wavelength conversion members 11 by one. A device for measuring at a location, a support portion 12 for supporting the wavelength conversion member 11, a light source portion 13 for irradiating the wavelength conversion member 11 with excitation light, and an objective lens 14 for capturing light emitted from the wavelength conversion member 11. A moving mechanism 15 for moving the wavelength conversion member 11 supported by the support section 12, a spectroscope 16 for measuring the spectrum of light passing through the objective lens 14, and a temperature adjusting section 44 for controlling the temperature of the light source section 13. , And a control unit 19 for driving and controlling these.

  The wavelength conversion member 11 is formed by molding a phosphor composition in which a yellow phosphor is mixed with a ceramic or a synthetic resin into a sheet shape. The wavelength conversion member 11 transmits excitation light in a blue region having a center wavelength of 435 to 480 nm, and excites the yellow phosphor by the transmitted excitation light to generate fluorescence in a yellow region having a center wavelength of 530 to 580 nm. That is, when the wavelength conversion member 11 is irradiated with the excitation light in the blue region, the excitation light in the blue region and the fluorescence in the yellow region are emitted, and these lights are combined to produce white light (pseudo white light). Released as

  The support section 12 includes an adhesive sheet 18 and an annular sheet holding frame 20. The adhesive sheet 18 is made of an elastic vinyl sheet such as a synthetic resin, a polyester sheet, or the like, and is attached to one surface of the sheet holding frame 20 so as to cover the hollow portion 20 a of the sheet holding frame 20. An adhesive is applied to one surface of the annular pressure-sensitive adhesive sheet 18 and the wavelength conversion member 11 is attached thereto. In addition, it is preferable that the adhesive sheet 18 affixed to the wavelength conversion member 11 be colorless and transparent.

  The sheet holding frame 20 is attached to the peripheral portion of the adhesive sheet 18 to which the wavelength conversion member 11 is attached, and is detachably fixed to the moving mechanism 15.

  The moving mechanism 15 includes: an X guide rail 24 extending in one direction (X-axis direction) in a horizontal plane provided on the base portion 17; an X table 26 slidably provided on the X guide rail 24; A Y guide rail 28 extending in a direction perpendicular to the X axis direction (Y axis direction), and a Y table 30 slidably provided on the Y guide rail 28 are provided.

  The X table 26 is driven by an X-axis drive motor 27 (see FIG. 2), and moves on the guide rail 24 in the X-axis direction. A guide rail 28 and a Y table 30 are provided on the X table 26. The X table 26 and the Y table 30 are provided with hollow portions 32 communicating vertically.

  The Y table 30 detachably fixes the support portion 12 so that the adhesive sheet 18 is located above the hollow portion 32. In the present embodiment, the support section 12 is attached to the Y table 30 so that the wavelength conversion member 11 is located above the adhesive sheet 18. The Y table 30 is driven by a Y-axis drive motor 31 and moves on the guide rail 28 in the Y-axis direction. Thus, the support portion 12 fixed on the Y table 30 can move in the X-axis direction and the Y-axis direction with respect to the base portion 17.

  A light source section 13 fixed to the base section 17 is provided below the hollow section 32 provided in the X table 26 and the Y table 30, and the wavelength conversion member 11 and the light source section 13 supported by the support section 12 are vertically moved. To be opposed.

  The light source unit 13 includes an excitation light source 34 composed of a blue LED (Light Emitting Diode) that generates excitation light for irradiating the wavelength conversion member 11, and an excitation filter 36 that transmits only light in a predetermined wavelength band. Only the light in a predetermined wavelength band out of the light emitted from 34 is irradiated to the wavelength conversion member 11 from below as excitation light. When the light source unit 13 irradiates the excitation light from below the wavelength conversion member 11, the excitation light (transmitted light) transmitted through the wavelength conversion member 11 and the fluorescent light generated when the yellow phosphor is excited when transmitted through the wavelength conversion member 11. Are emitted from the upper surface of the wavelength conversion member 11.

  The excitation light emitted from the light source unit 13 to the wavelength conversion member 11 is preferably diffused light that is not condensed by a condenser lens or the like and has no directivity. The region where the light source unit 13 irradiates the wavelength conversion member 11 preferably irradiates a region sufficiently wider than the range of the actual field of view of the objective lens 14, and may irradiate the entire lower surface of the wavelength conversion member 11, A part of the lower surface of the wavelength conversion member 11 may be irradiated. For example, the distance D from the light emitting surface of the excitation light source 34 to the wavelength conversion member 11 is preferably 10 times or more the diameter φ of the light emitting surface of the excitation light source 34. By setting the distance D to be 10 times or more the diameter φ of the light emitting surface of the excitation light source 34, the wavelength conversion member 11 can be irradiated with a uniform amount of light (diffused light). Further, in addition to making the distance D 10 times or more the diameter φ or changing the distance D to 10 times or more the diameter φ, the distance D between the excitation light source 34 and the wavelength conversion member 11 is changed. May be provided with a light diffusion film or an optical system, and the wavelength conversion member 11 may be irradiated with a uniform amount of light (diffused light).

  An objective lens 14 attached to a lower end of a lens barrel 38 is disposed above the wavelength conversion member 11 supported by the support unit 12. The objective lens 14 faces the light source unit 13 with the wavelength conversion member 11 interposed therebetween, and is disposed above the light source unit 13 in this example. The objective lens 14 includes the excitation light (transmitted light) transmitted through the wavelength conversion member 11 emitted from the upper surface of the wavelength conversion member 11 when the light source unit 13 irradiates the wavelength conversion member 11 with excitation light from below, and a yellow phosphor. Captures only the excitation light and the fluorescence emitted from the range of the actual field of view from the fluorescence generated by the excitation.

  A light receiving fiber 40 for guiding light captured by the objective lens 14 to the spectroscope 16 is connected to an upper end of the lens barrel 38.

  The spectroscope 16 splits the light captured by the objective lens 14 to detect a spectrum of the light, and inputs the detected spectrum to the control unit 19.

  The temperature control section 44 is provided on the base section 17 so as to be in contact with the light source section 13 and exchange heat. The temperature adjustment unit 44 includes a heat source such as a Peltier element that generates heat or cold, and a temperature sensor that detects the temperature of the light source unit 13. The temperature adjustment unit 44 is provided on the base unit 17 in a state where heat exchange with the light source unit 13 is possible. I have. The temperature control unit 44 controls the light source unit 13 to be at a predetermined temperature by heating or cooling the light source unit 13 with heat or cold generated from a heat source while detecting the temperature of the light source unit 13 with a temperature sensor. . Further, if necessary, the temperature adjusting unit 44 changes the temperature of the light source unit 13 to change the center wavelength of the excitation light emitted from the light source unit 13.

  The control unit 19 includes a computer, and is connected to the light source unit 13, the spectroscope 16, the X-axis drive motor 27, the Y-axis drive motor 31, the camera 42, and the temperature control unit 44 as shown in FIG.

  The control unit 19 controls the light source unit 13, the X-axis drive motor 27, the Y-axis drive motor 31, and the temperature control unit 44 according to a predetermined program, and also conforms to JIS Z8724: 1997 (color measurement method-light source color-). Xy chromaticity coordinates on the CIE 1931 chromaticity diagram are calculated from the spectrum detected by the spectroscope 16 based on

  The control unit 19 also includes information about the position and size of the wavelength conversion member 11 input from a camera 42 (see FIG. 2) that images the wavelength conversion member 11 supported by the support unit 12, and the X-axis drive motor 27. From the position information of the X table 26 and the Y table 30 input from the Y-axis drive motor 31, the position on the wavelength conversion member 11 at which the objective lens 14 captures the excitation light and the fluorescence is detected.

  Next, the operation of the inspection device 10 will be described.

  First, when the support portion 12 having the wavelength conversion member 11 attached to the adhesive sheet 18 is set on the Y table 30 of the moving mechanism 15, the camera 42 captures an image of the wavelength conversion member 11, and detects the position and size of the wavelength conversion member 11. I do. Further, the control unit 19 controls the temperature adjustment unit 44 so that the light source unit 13 is maintained at a predetermined constant temperature during the operation of the inspection device 10.

  The control unit 19 changes the center wavelength of the excitation light emitted from the light source unit 13 by controlling the temperature adjustment unit 44 as needed to change the temperature of the light source unit 13, and to the wavelength conversion unit 11. The wavelength of the excitation light to be irradiated may be adjusted to a desired wavelength.

  Next, the control unit 19 turns on the excitation light source 34 of the light source unit 13 and irradiates the wavelength conversion member 11 with the excitation light from below, and emits the excitation light and the fluorescence emitted from above the wavelength conversion member 11 to the objective lens. At 14, the spectrum of the light taken at the spectroscope 16 from the objective lens 14 is detected, and the xy chromaticity coordinates are calculated from the detection result.

  In addition, the control unit 19 detects the position information of the wavelength conversion member 11 into which the objective lens 14 has captured the excitation light and the fluorescence, and stores the detected position information and the xy chromaticity coordinates obtained at the position in association with each other. .

  Then, the control unit 19 controls the X-axis drive motor 27 and the Y-axis drive motor 31 of the moving mechanism 15 to move the wavelength conversion member 11 by a size corresponding to the actual field of view of the objective lens 14, and again, The excitation light and the fluorescence emitted from above the wavelength conversion member 11 are captured by the objective lens 14, the spectrum of the light captured from the objective lens 14 is detected by the spectroscope 16, and the xy chromaticity coordinates are calculated from the detection result. Then, the position information of the wavelength conversion member 11 that has obtained the xy chromaticity coordinates is stored. The light source unit 13 may be turned off while the wavelength conversion member 11 is moving, and the light source unit 13 may be turned on while the wavelength conversion member 11 is stopped and the spectroscope 16 is being measured. The light source unit 13 may be kept turned on regardless of the stop.

  Thereafter, the movement of the wavelength conversion member 11 and the calculation of the xy chromaticity coordinates are repeated, and the xy chromaticity coordinates are measured on the entire surface of the wavelength conversion member 11, so that the wavelength is set at a pitch corresponding to the actual field of view of the objective lens 14. The in-plane distribution of the xy chromaticity coordinates of the conversion member 11 can be measured.

  In the inspection apparatus 10 of the present embodiment as described above, only the transmitted light and the fluorescence emitted from the narrow area corresponding to the actual field of view of the objective lens 14 of the wavelength conversion member 11 are taken into the spectroscope 16 and the xy chromaticity coordinates are obtained. Therefore, the in-plane distribution of the chromaticity coordinates of the wavelength conversion member 11 can be easily and accurately measured without being affected by light emitted from a position close to the measurement position.

  Moreover, the pitch for measuring the xy chromaticity coordinates can be easily changed by changing the magnification of the objective lens 14.

  In addition, in the inspection device 10 of the present embodiment, since the excitation light applied to the wavelength conversion member 11 is diffuse light having no directivity, compared with the case where the light collected as excitation light is applied to the wavelength conversion member 11, When passing through the wavelength conversion member 11, the yellow phosphor is excited to easily generate fluorescence, and the transmitted light and the fluorescence can be accurately measured by the same measurement system.

  In the inspection device 10 of the present embodiment, the wavelength conversion member 11 is moved, and the light source unit 13 and the objective lens 14 are stopped, so that the configuration of the moving mechanism 15 is simplified. In addition to this, the position of the objective lens 14 is easily stabilized, and the position of the light source unit 13 with respect to the objective lens 14 does not change, so that the wavelength conversion member 11 can be irradiated with excitation light under the same conditions. The chromaticity coordinates of the conversion member 11 can be accurately measured.

  Further, in the present embodiment, since the temperature of the light source unit 13 is controlled by the temperature adjustment unit 44 so that the temperature of the light source unit 13 becomes constant, the wavelength of the excitation light that the light source unit 13 irradiates the wavelength conversion member 11 is hard to change. Thus, highly accurate measurement can be performed.

  Further, in the present embodiment, since the pressure-sensitive adhesive sheet 18 attached to the wavelength conversion member 11 is colorless and transparent, the excitation light applied to the wavelength conversion member 11 is not affected by the pressure-sensitive adhesive sheet 18 and the wavelength conversion is performed with high accuracy. The chromaticity coordinates of the member 11 can be measured.

  In the present embodiment, since the excitation light source 34 of the light source unit 13 is an LED and the wavelength of the light emitted from the excitation light source 34 has a wide range, the wavelength of the excitation light radiated to the wavelength conversion member 11 by the excitation filter 36 or the like. Can be selected, and the wavelength conversion member 11 can be irradiated with excitation light having different wavelengths.

  Next, a modification of the above embodiment will be described.

(Modification 1)
In the above-described embodiment, the case where the wavelength conversion member 11 measures the in-plane distribution of the chromaticity coordinates of one sheet-like wavelength conversion member 11 has been described. By setting the actual field of view of the objective lens 14 to the size of one wavelength conversion member, the chromaticity coordinates of each wavelength conversion member can be measured.

  Further, in the present embodiment, the wavelength conversion member 11 is intermittently moved at a pitch corresponding to the actual field of view of the objective lens 14, but the wavelength conversion member 11 is moved at a constant speed so that the chromaticity coordinates are continuously in-plane. May be measured.

(Modification 2)
In the above-described embodiment, the case where the moving mechanism 15 moves the wavelength conversion member 11 with respect to the objective lens 14 has been described. However, the objective lens 14 may be moved while the wavelength conversion member 11 is stopped. In that case, in order to irradiate the wavelength conversion member 11 with excitation light under the same conditions, a light source moving mechanism for moving the light source unit 13 is provided, and the light source unit 13 and the objective lens 14 are vertically opposed with the wavelength conversion member 11 interposed therebetween. It is preferable to move the light source unit 13 in synchronization with the objective lens 14 so that

(Modification 3)
In the above-described embodiment, the case where the moving mechanism 15 moves the wavelength conversion member 11 in a horizontal plane (XY plane) has been described. For example, the moving mechanism 15 rotates the Y table 30 about a horizontal axis, or Alternatively, the angle of the wavelength conversion member 11 with respect to the optical axis of the objective lens 14 may be changed by turning the objective lens 14 around the upper surface of the wavelength conversion member 11. In such a case, the xy chromaticity coordinates when the excitation light is transmitted in a direction inclined with respect to the thickness direction of the wavelength conversion member 11 can be measured.

(Modification 4)
In the above-described embodiment, the light source unit 13 is maintained at a constant temperature by the temperature control unit 44 continuously during the operation of the inspection apparatus 10. However, for example, the state in which the temperature control unit 44 holds the light source unit 13 at the first temperature T1. Then, the in-plane distribution of the chromaticity coordinates of the wavelength conversion member 11 is measured, and then the temperature control unit 44 changes the temperature of the light source unit 13 from the first temperature T1 to a second temperature T2 different from the first temperature T1 and is emitted from the light source unit 13. After changing the wavelength of the excitation light, the in-plane distribution of the chromaticity coordinates of the wavelength conversion member 11 may be measured again.

  By irradiating the wavelength conversion member with excitation light having a plurality of different wavelengths and measuring the chromaticity coordinates in this manner, it is also possible to inspect the change in the chromaticity characteristics of the wavelength conversion member 11 when the wavelength of the excitation light changes. Can be.

(Modification 5)
In the above-described embodiment, an LED is used as the excitation light source 34 of the light source unit 13 that generates excitation light to irradiate the wavelength conversion member 11. However, for example, an LD (Laser Diode) may be used as the excitation light source 34.

  By using an LD as the excitation light source 34 of the light source unit 13, light having high monochromaticity can be applied to the wavelength conversion member 11 as excitation light. In particular, when the excitation light source 34 is an LD, the wavelength change of the light emitted from the excitation light source 34 when the temperature of the light source unit 13 is changed by the temperature control unit 44 becomes remarkable, and when the wavelength of the excitation light changes. A change in the chromaticity characteristics of the wavelength conversion member 11 can be inspected with high accuracy.

  When an LD is used as the excitation light source of the light source unit 13, a light diffusion film or an optical system is provided between the excitation light source 34 and the wavelength conversion member 11 so that a uniform amount of light (diffusion (Light).

(Other embodiments)
As described above, the embodiment of the present invention has been described. However, this embodiment is presented as an example.
It is not intended to limit the scope of the invention. This embodiment can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Inspection apparatus, 11 ... Wavelength conversion member, 12 ... Support part, 13 ... Light source part, 14 ... Objective lens, 15 ... Moving mechanism, 16 ... Spectroscope, 17 ... Base part, 18 ... Adhesive sheet, 19 ... Control part , 20: sheet holding frame, 24: X guide rail, 26: X table, 27: X axis drive motor, 28: Y guide rail, 30: Y table, 31: Y axis drive motor, 32: hollow portion, 34 ... Excitation light source, 36: excitation filter, 38: lens barrel, 40: light receiving fiber, 42: camera

Claims (10)

In an inspection device for inspecting a wavelength conversion member containing a phosphor,
A support for supporting the wavelength conversion member,
A light source unit that irradiates the wavelength conversion member with excitation light that is diffused light ,
An objective lens that captures the fluorescence emitted from the wavelength conversion member by the irradiation of the excitation light and the excitation light transmitted through the wavelength conversion member,
A moving mechanism that moves at least one of the objective lens and the wavelength conversion member,
A spectroscope for measuring the spectrum of the light captured by the objective lens,
Wherein the plurality of different positions wavelength converting member takes the objective lens is said excitation light transmitted through the fluorescent and said actual viewing range emanating from a narrow actual field of view than the irradiation range of the excitation light in the wavelength conversion member, wherein An inspection apparatus in which the spectroscope measures the spectrum of light captured by the objective lens.   The inspection device according to claim 1, wherein the light source unit is provided at a position farther from the wavelength conversion member than the objective lens.   The inspection apparatus according to claim 1, wherein the moving mechanism moves at least one of the objective lens and the wavelength conversion member at a pitch corresponding to a real field range of the objective lens. The inspection device according to any one of claims 1 to 3, wherein the moving mechanism stops the light source unit and the objective lens and moves the wavelength conversion member. The inspection device according to any one of claims 1 to 3, wherein the moving mechanism stops the wavelength conversion member and moves the objective lens. The inspection apparatus according to claim 5 , further comprising a light source moving mechanism that moves the light source unit in synchronization with the objective lens. The inspection device according to any one of claims 1 to 6 , wherein the moving mechanism changes an angle of the wavelength conversion member with respect to an optical axis of the objective lens. The inspection device according to any one of claims 1 to 7 , further comprising a temperature control unit that controls a temperature of the light source unit. The inspection device according to claim 8 , wherein the temperature adjustment unit changes a temperature of the light source unit to change a wavelength of excitation light emitted from the light source unit. The inspection device according to any one of claims 1 to 9 , wherein the support unit includes a colorless and transparent holding sheet that fixes the wavelength conversion member by bonding.

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