JP7200936B2 - Measuring optics, luminance and colorimeters - Google Patents

Description

The present invention relates to a measurement optical system for guiding light from an object to be measured to a light receiving section, a color luminance meter using the same, and a colorimeter using the same.

Colorimeters that measure the color (light source color) and luminance of a luminous body as an object to be measured, and colorimeters that measure the color of an object as an object (object color) have been known and used in various ways. It has been. An optical system for measurement that guides light from an object to be measured to a light-receiving part is used in such a color luminance meter and colorimeter, and is disclosed in Japanese Patent Application Laid-Open No. 2002-200014, for example.

The optical device for measurement disclosed in Patent Document 1 includes a light branching means having a plurality of exit surfaces for branching and exiting the light from the object to be measured that is incident on the entrance surface. More specifically, the optical apparatus for measurement disclosed in Patent Document 1 includes an optical system KK2 including an objective lens 103, an aperture stop 104, a field stop 105, a relay lens 106, a bundle fiber 22, and the like (FIG. 9). and [0042] paragraphs, etc.). The objective lens 103 converges the luminous flux from the object Q to be imaged at the position of the field stop 105 . The relay lens 106 guides the image formed at the position of the field stop 105 to the plane of incidence A of the bundle fiber 22 . Aperture diaphragm 104 is arranged behind objective lens 103 , and only the luminous flux that has passed through aperture diaphragm 104 is directed to relay lens 106 . The bundle fiber 22 corresponds to the light branching means, is configured by bundling a plurality of optical fiber strands, and is divided into three at an intermediate portion in the axial direction. , B2, and B3. The relay lens 106 is arranged at a position such that the aperture stop 104 and the plane of incidence A are in an optically conjugate relationship. In this paragraph, the reference numerals are the numerals given to each configuration in the aforementioned Patent Document 1.

By the way, in recent years, not only liquid crystal displays but also organic EL (electro luminescence) displays have attracted attention as display devices. Compared to a liquid crystal display using a backlight, the organic EL display is self-luminous and can emit light even in a low luminance range. It is desirable to be able to more accurately measure the light emission in this low luminance range, and for this reason, a measuring optical system that guides a greater amount of light from the object to be measured to the light receiving section is desired.

In the optical device for measurement disclosed in Patent Document 1, a luminous flux having an incident angle equal to or greater than the angle corresponding to the numerical aperture of the bundle fiber (optical fiber bare wire) enters the bundle fiber (optical fiber bare wire). Therefore, light quantity loss occurs.

JP-A-2003-247891

The present invention has been made in view of the above circumstances, and its object is to provide a measurement optical system capable of guiding a greater amount of light from an object to be measured to a light receiving part, a color luminance meter using the same, and a color luminance meter using the same. is to provide a colorimeter using

In order to achieve the above object, a measuring optical system, a color luminance meter, and a colorimeter reflecting one aspect of the present invention are provided with an aperture, an optical waveguide for guiding incident light, and an object side of the aperture. , a first optical system for forming an optical image from an object to be measured on the aperture plane of the diaphragm, and a first optical system arranged between the aperture and the optical waveguide, and each principal ray of each light beam emitted from the aperture plane of the diaphragm is aligned with the optical axis; and a second optical system for making the light incident on the optical waveguide so as to be parallel to .

The advantages and features provided by one or more embodiments of the invention will be fully appreciated from the detailed description given below and the accompanying drawings. These detailed descriptions and accompanying drawings are given by way of example only and are not intended as a definition of the limits of the invention.

1 is a block diagram showing the configuration of a color luminance meter in a first embodiment; FIG. It is a figure which shows the structure of the optical system for a measurement used for the said color luminance meter. FIG. 3 shows a ray diagram of each light flux from the exit surface of the second optical system to the entrance surface of the optical waveguide in the measurement optical system. It is a figure which shows the structure of the optical system for a measurement in 2nd Embodiment. FIG. 11 is a diagram showing the configuration of a measurement optical system in a third embodiment; FIG. 11 is a block diagram showing the configuration of a colorimeter in fourth to sixth embodiments; FIG. It is a figure which shows the structure of the optical system for a measurement in a comparative example.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment according to the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. It should be noted that the configurations denoted by the same reference numerals in each figure indicate the same configurations, and the description thereof will be omitted as appropriate. In the present specification, reference numerals with suffixes omitted are used when referring to generically, and reference numerals with suffixes are used when referring to individual configurations.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of a color luminance meter according to the first embodiment. It should be noted that FIG. 1 is also a block diagram showing the configuration of color luminance meters Db and Dc in second and third embodiments which will be described later. FIG. 2 is a diagram showing the configuration of a measurement optical system used in the color luminance meter. FIG. 2A shows the optical system for measurement in the first embodiment, and FIG. 2B shows a bundle fiber as an example of an optical waveguide. FIG. 3 shows a ray diagram of each light flux from the exit surface of the second optical system to the entrance surface of the optical waveguide (bundle fiber) in the measurement optical system. FIG. 7 is a diagram showing the configuration of a measurement optical system in a comparative example. FIG. 7A shows the measuring optical system in a comparative example, and FIG. 7B shows a ray diagram of each light beam from the exit surface of the second optical system to the incident surface of the optical waveguide (bundle fiber) in the comparative example.

The color luminance meter Da in the first embodiment includes, for example, as shown in FIG. (IF section) 5;

The measurement optical system SSa is an optical component that receives light from the object to be measured Ob, which is the object to be measured, and guides the received light to the light receiving section 1 . The measurement optical system SSa will be described in more detail later. In this embodiment, the object to be measured Ob is the color luminance meter Da, and is therefore a luminous body that emits light.

The light-receiving part 1 is a light-receiving component that receives light from the object to be measured Ob guided by the optical system for measurement SSa, photoelectrically converts the received light, and outputs an electric signal corresponding to the intensity of the light. is. The light-receiving unit 1 includes, for example, a spectroscopic unit that spectroscopically separates the received light from the object to be measured Ob, and a photoelectric conversion element that photoelectrically converts the light separated by the spectroscopic unit. More specifically, in this embodiment, since the color and brightness of the object Ob to be measured are measured from the XYZ tristimulus values, the light receiving unit 1 uses the color matching function X , Y, and Z, and three X filters 11-1, Y filters 11-2, and Z filters 11-3, respectively. An X filter light receiving element 12-1, a Y filter light receiving element 12-2, and a Z filter light receiving element 12-3 for receiving and photoelectrically converting the respective filtered lights are provided. In such a light receiving unit 1, the light from the object to be measured Ob is filtered by the X filter 11-1, the filtered light is received by the X filter light receiving element 12-1, photoelectrically converted, The light receiving element 12-1 for X filter outputs an electric signal (X signal) corresponding to the light intensity thereof. is received by the Y filter light receiving element 12-2 and photoelectrically converted. The light from Ob is filtered by the Z filter 11-3, the filtered light is received by the Z filter light receiving element 12-3, photoelectrically converted, and the Y filter light receiving element 12-1 An electrical signal (Z signal) corresponding to the light intensity is output. The light receiving section 1 is connected to the control processing section 2a, and these X signal, Y signal and Z signal are output to the control processing section 2a.

The input unit 3 is connected to the control processing unit 2a, for example, various commands such as a command to instruct measurement of the object to be measured Ob, which is an object to be measured, and an identifier (specimen number, ID, name, etc.) of the object to be measured Ob etc.) to input various data necessary for measurement to the color luminance meter Da, for example, a plurality of input switches to which predetermined functions are assigned. The output unit 4 is connected to the control processing unit 2a, and according to the control of the control processing unit 2a, the commands and data input from the input unit 3, and the color and data of the object to be measured Ob measured by the color luminance meter Da. A device for outputting luminance, for example, a display device such as a CRT display, an LCD (liquid crystal display device) or an organic EL display, or a printing device such as a printer.

A touch panel may be configured from the input unit 3 and the output unit 4 . In the case of constructing this touch panel, the input unit 3 is a position input device for detecting and inputting an operation position, such as a resistive film method or a capacitive method, and the output unit 4 is a display device. In this touch panel, a position input device is provided on the display surface of the display device, one or a plurality of input content candidates that can be input are displayed on the display device, and the user touches the display position where the input content that the user wants to input is displayed. Then, the position is detected by the position input device, and the display content displayed at the detected position is input to the color luminance meter Da as the user's operation input content. With such a touch panel, the user can easily intuitively understand the input operation, so that the color luminance meter Da is provided which is easy for the user to handle.

The IF unit 5 is a circuit that is connected to the control processing unit 2a and performs data input/output with an external device under the control of the control processing unit 2a. , an interface circuit using the Bluetooth (registered trademark) standard, an interface circuit for infrared communication such as the IrDA (Infrared Data Association) standard, and an interface circuit using the USB (Universal Serial Bus) standard. The IF section 5 is a circuit for communicating with an external device, and may be, for example, a data communication card or a communication interface circuit conforming to the IEEE802.11 standard.

The control processing unit 2a controls each unit 1, 3 to 5 of the color luminance meter Da according to the function of each unit, and controls the entire color luminance meter Da. Then, the control processing unit 2a measures the light from the object to be measured Ob with the measurement optical system SSa and the light receiving unit 1 according to the instruction received by the input unit 3, and based on the electric signal output from the light receiving unit 1, to obtain the color and luminance of the object to be measured Ob, and output the obtained color and luminance of the object to be measured Ob to the output unit 4 . Further, the control processing unit 2a outputs the determined color and luminance of the object to be measured Ob from the IF unit 5 as necessary. In this embodiment, the control processing unit 2a obtains the color and brightness of the object to be measured Ob from the X signal, Y signal and Z signal output from the light receiving unit 1 by a known technique. The control processing unit 2a is configured with, for example, a microprocessor.

The measurement optical system SSa will be described in more detail below. For example, as shown in FIG. 2, the measurement optical system SSa includes a first optical system OSa-1, a diaphragm DI, a second optical system OSa-2, and an optical waveguide OP.

The diaphragm DI is an optical element that regulates the measurement diameter, and is, for example, a plate-like member that has a circular through-opening corresponding to the measurement diameter and has a light shielding property. The through opening forms an opening surface.

The optical waveguide OP is an optical element that guides incident light. It is an optical splitter that splits the incident light into three to guide the light to each of 11-3. More specifically, in this embodiment, as shown in FIG. 2B, the optical waveguide OP divides a plurality of bundled optical fiber strands into three bundles on the way, and the light enters from one incident surface. It is a bundle fiber that emits incident light that has passed through three first to third exit surfaces, respectively.

The first optical system OSa-1 is arranged on the object side (object to be measured Ob side) of the diaphragm DI, and is an optical system that forms an optical image from the object to be measured Ob as an intermediate image on the aperture surface of the diaphragm DI. element. More specifically, in this embodiment, as shown in FIG. 2A, the first optical system OSa-1 has positive refractive power (optical power, reciprocal of focal length), It consists of two first and second lens groups Gra-1 and Gra-2 for forming an intermediate image on the aperture surface of the diaphragm DI so that the light image from Ob is telecentric on the object side. Therefore, as shown in FIG. 2A, each principal ray of each light flux emitted from the object to be measured Ob enters the first lens group Gra-1 so as to be parallel to the optical axis. Note that the principal ray is said to be parallel to the optical axis not only when the principal ray is completely parallel to the optical axis, but also when the principal ray deviates within ±1 degree from the optical axis due to manufacturing variations, etc. , is the margin of error and is considered parallel. The first and second lens groups Gra-1 and Gra-2, like the lens groups Grb to Grf described later, are configured with one or more lenses.

The second optical system OSa-2 is arranged between the diaphragm DI and the optical waveguide OP, and is arranged in the optical waveguide OP such that the principal rays of the beams emitted from the aperture surface of the diaphragm DI are parallel to the optical axis. It is an optical element that allows light to enter. That is, the second optical system OSa-2 is an image-side telecentric relay lens, and is composed of, for example, one lens group Grb.

As can be seen from the above description, in such a measurement optical system SSa, the first optical system OSa-1, the diaphragm DI, the second optical system OSa-2, and the optical waveguide OP are arranged in this order. A diaphragm DI is arranged at the imaging position of the first optical system OSa-1. Light from the object to be measured Ob to be measured enters the first lens group Gra-1 of the first optical system OSa-1 such that the principal rays of the respective light beams are parallel to the optical axis. The first optical system OSa-1, with its positive refractive power, forms an intermediate image of the light image from the object to be measured Ob on the aperture surface of the diaphragm DI, and the diaphragm DI receives light from the object to be measured Ob. It is regulated by the measurement diameter and made incident on the second optical system OSa-2. As a result, the measurement optical system SSa can achieve uniform measurement sensitivity with sharp edges, and can guide a large amount of light even with a relatively small measurement diameter. In addition, since the second optical system OSa-2 does not provide an image forming relationship as in the case of both-side telecentricity, the measurement optical system SSa is less susceptible to unevenness on the measurement surface.

Then, the second optical system OSa-2 causes the light from the object to be measured Ob restricted by the diaphragm DI to enter the optical waveguide OP such that the principal rays of the respective light beams are parallel to the optical axis. Therefore, the optical system for measurement SSa can reduce the amount of light loss that occurs when the off-axis light beam has a large incident angle, and has good light collection efficiency. A more detailed description will be given using a comparative example. As shown in FIG. 7, the measurement optical system SSr of this comparative example is similar to that shown in FIG. is constructed in the same manner as the above-described measurement optical system SSa shown.

In general, propagation of light entering an optical waveguide is regulated by the numerical aperture NA of the optical waveguide. That is, light that is incident within a three-dimensional angle corresponding to the numerical aperture NA of the optical waveguide can propagate through the optical waveguide, but light that is incident beyond the three-dimensional angle corresponding to the numerical aperture NA of the optical waveguide can propagate through the optical waveguide. Cannot propagate through an optical waveguide. Therefore, in order to allow a larger amount of light to enter the optical waveguide OP, which is the bundle fiber OP in this embodiment, the image-side numerical aperture NA1 of the measurement optical system SSa must be equal to the numerical aperture NA2 of the optical waveguide (bundle fiber) OP. It is efficient to match Even if the numerical aperture NA1 and the numerical aperture NA2 are matched to each other in this way, in the case of the measurement optical system SSr in the comparative example, as shown in FIG. All the light beams can propagate through the optical waveguide (bundle fiber) OP. Since there are rays of light incident beyond the solidification angle corresponding to the numerical aperture NA2, none of the rays can propagate through the optical waveguide (bundle fiber) OP, resulting in loss of the amount of light. That is, a loss of light quantity occurs due to the off-axis light flux having a large incident angle. On the other hand, in the case of the measurement optical system SSa in this embodiment, as shown in FIG. is telecentric on the image side, the off-axis luminous flux consisting of the light beams B_+1, B_0, and B_-1 also has its luminous flux center vertically incident like the on-axis luminous flux, and can all propagate through the optical waveguide (bundle fiber) OP. Therefore, the measurement optical system SSa in the present embodiment can reduce the loss of light amount caused by the off-axis light flux having a large incident angle, and has good light collection efficiency.

Then, the light from the object to be measured Ob that has entered the optical waveguide OP, which is the bundle fiber OP in this embodiment, propagates through the bundle fiber OP, splits into three, and exits from the first to third exit surfaces, respectively.

The optical waveguide OP and the light receiving section 1 are arranged such that the incident surface of the light receiving section 1 faces the output surface of the optical waveguide OP. In this embodiment, as shown in FIG. 2B, the incident surface of the X filter 11-1 of the light receiving unit 1 faces the first output surface of the bundle fiber OP, and the second output surface of the bundle fiber OP so that the incident surface of the Y filter 11-2 of the light receiving unit 1 faces the incident surface of the Y filter 11-2 of the light receiving unit 1, and the incident surface of the Z filter 11-3 of the light receiving unit 1 faces the third output surface of the bundle fiber OP. The bundle fiber OP and the light receiving section 1 are arranged.

Light from the object to be measured Ob emitted from the optical waveguide OP is incident on the light receiving section 1 . In this embodiment, the light from the object to be measured Ob emitted from the first emission surface of the bundle fiber OP enters the X filter 11-1 of the light receiving unit 1, is filtered by the X filter 11-1, and is filtered by the X filter 11-1. The received light is received by the X-filter light-receiving element 12-1. The light from the object to be measured Ob emitted from the second emission surface of the bundle fiber OP is incident on the Y filter 11-2 of the light receiving unit 1 and filtered by the Y filter 11-2. The light is received by the filter light receiving element 12-2. Then, the light from the object to be measured Ob emitted from the third emission surface of the bundle fiber OP is incident on the Z filter 11-3 of the light receiving unit 1, filtered by the Z filter 11-1, and the filtered light is , are received by the Z-filter light-receiving element 12-3.

Then, as described above, the X filter light receiving element 12-1 outputs an X signal corresponding to the light intensity of the light filtered by the X filter 11-1 to the control processing unit 2a, and the Y filter light receiving element 12- 2 outputs a Y signal corresponding to the light intensity of the light filtered by the Y filter 11-2 to the control processing unit 2a, and the Z filter light receiving element 12-3 receives the light filtered by the Z filter 11-3. A Z signal corresponding to the intensity is output to the control processing unit 2a. The control processing unit 2a obtains the color and luminance of the object to be measured Ob from the X signal, Y signal and Z signal output from the light receiving unit 1, and outputs the obtained color and luminance of the object to be measured Ob to the output unit 4. Output.

As described above, in the measurement optical system SSa used in the color luminance meter Da in this embodiment, the first optical system OSa-1 receives the light image from the object to be measured Ob, which is the object to be measured, and the aperture of the diaphragm DI. An intermediate image is formed by forming an image on a plane, and the second optical system OSa-2 forms an optical waveguide (this embodiment in the form of a bundle fiber) OP. For this reason, the measurement optical system SSa can reduce the amount of light loss that occurs when the off-axis light beam has a large incident angle, and has good light collection efficiency. Since the measurement optical system SSa forms the intermediate image, it is possible to achieve uniform measurement sensitivity with sharp edges, and to guide a large amount of light even with a relatively small measurement diameter. Therefore, the measurement optical system SSa can guide a larger amount of light from the object to be measured Ob to the light receiving section 1 .

Because the second optical system OSa-2 prevents the measurement optical system SSa from forming an image unlike the double-telecentric system, the measurement optical system SSa is less likely to be affected by unevenness on the measurement surface. In the measurement optical system SSa, since the first optical system OSa-1 consists of the two first and second lens groups Gra-1 and Gra-2, a larger amount of light can be collected, and if necessary It also makes it easier to correct chromatic aberration.

Since such a measurement optical system SSa is used, the color luminance meter Da in the first embodiment can improve the S/N ratio and perform colorimetry with higher accuracy. The color luminance meter Da is particularly advantageous for measurement of low luminance regions. In addition, the color luminance meter Da can have a smaller measurement diameter and an improved spatial resolution.

(Second embodiment)
Next, another embodiment will be described. FIG. 4 is a diagram showing the configuration of the measurement optical system in the second embodiment.

The color luminance meter Da in the first embodiment uses a measurement optical system SSa comprising two first and second lens groups Gra-1 and Gra-2, and these first and second lens groups Gra-1, Although Gra-2 forms an intermediate image of the object to be measured Ob, the color luminance meter Db in the second embodiment uses a measurement optical system SSb that forms an intermediate image with one lens group Grc.

For example, as shown in FIG. 1, the color luminance meter Db in the second embodiment includes a measurement optical system SSb, a light receiving section 1, a control processing section 2a, an input section 3, and an output section 4. , and an IF unit 5 . The light receiving unit 1, the control processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5 in the color luminance meter Db of the second embodiment correspond to the light receiving unit 1, the control unit, and the control unit in the color luminance meter Da of the first embodiment, respectively. Since it is the same as the processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5, the description thereof will be omitted.

For example, as shown in FIG. 4, the measurement optical system SSb used in the color luminance meter Db in the second embodiment includes a first optical system OSb-1, a diaphragm DI, a second optical system OSb-2, and an optical waveguide OP.

The diaphragm DI is an optical element that regulates the measurement diameter, like the measurement optical system SSa of the first embodiment. The optical waveguide OP is an optical element that guides incident light, as in the measurement optical system SSa of the first embodiment, and is also a one-input, three-output bundle fiber OP in this embodiment.

The first optical system OSb-1 is arranged on the object side (object to be measured Ob side) of the diaphragm DI and forms an optical image from the object to be measured Ob as an intermediate image on the aperture surface of the diaphragm DI. element. More specifically, in the present embodiment, as shown in FIG. 4, the first optical system OSb-1 has a positive refractive power, and the optical image from the object to be measured Ob to be measured is object-side telecentric. It is composed of one lens group Grc that forms an intermediate image on the aperture surface of the diaphragm DI so as to form an intermediate image.

The second optical system OSb-2 is arranged between the diaphragm DI and the optical waveguide OP, and is arranged in the optical waveguide OP such that the principal rays of the light beams emitted from the aperture surface of the diaphragm DI are parallel to the optical axis. It is an optical element that allows light to enter. That is, the second optical system OSb-2 is an image-side telecentric relay lens, and is composed of, for example, one lens group Grd.

The measurement optical system SSb used in the color luminance meter Db in the second embodiment is similar to the measurement optical system SSa used in the color luminance meter Da in the first embodiment. It is possible to reduce the amount of light loss caused by having a large incident angle, and the light collection efficiency is good. The measurement optical system SSb can achieve uniform measurement sensitivity with sharp edges, and can guide a large amount of light even with a relatively small measurement diameter. Therefore, the measurement optical system SSb can guide a larger amount of light from the object to be measured Ob to the light receiving section 1 . The measurement optical system SSb is less susceptible to unevenness on the measurement surface.

Further, the measurement optical system SSb can be configured more simply because the first optical system OSb-1 is composed of one lens group Grc.

Since such a measurement optical system SSb is used, the color luminance meter Db in the second embodiment has the same effects as the color luminance meter Da in the first embodiment.

(Third Embodiment)
Next, another embodiment will be described. FIG. 5 is a diagram showing the configuration of the measurement optical system in the third embodiment.

The color luminance meters Da and Db in the first and second embodiments use the measurement optical systems SSa and SSb provided with the object-side telecentric first optical systems OSa-1 and OSb-1. The luminance meter Dc uses a measurement optical system SSc that includes a normal first optical system OSc-1 that is not particularly telecentric on the object side.

For example, as shown in FIG. 1, the color luminance meter Dc in the third embodiment includes a measurement optical system SSc, a light receiving section 1, a control processing section 2a, an input section 3, and an output section 4. , and an IF unit 5 . The light receiving unit 1, the control processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5 in the color luminance meter Dc of the third embodiment correspond to the light receiving unit 1, the control unit, and the control unit in the color luminance meter Da of the first embodiment, respectively. Since it is the same as the processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5, the description thereof will be omitted.

For example, as shown in FIG. 5, the measurement optical system SSc used in the color luminance meter Dc in the third embodiment includes a first optical system OSc-1, a diaphragm DI, a second optical system OSc-2, and an optical waveguide OP.

The diaphragm DI is an optical element that regulates the measurement diameter, like the measurement optical system SSa of the first embodiment. The optical waveguide OP is an optical element that guides incident light, as in the measurement optical system SSa of the first embodiment, and is also a one-input, three-output bundle fiber OP in this embodiment.

The first optical system OSc-1 is arranged on the object side (object to be measured Ob side) of the diaphragm DI, and is an optical system that forms an optical image from the object to be measured Ob as an intermediate image on the aperture surface of the diaphragm DI. element. More specifically, in the present embodiment, as shown in FIG. 5, the first optical system OSc-1 has a positive refractive power, and stops the optical image from the object to be measured Ob as an intermediate image. It consists of one lens group Gre that forms an image on the aperture plane of DI. The lens group Gre need not be particularly telecentric on the object side, and may be a normal optical system. The first optical system OSc-1 has a positive refractive power, and is composed of a plurality of lens groups Gre for forming an intermediate image on the aperture surface of the diaphragm DI from an optical image from the object Ob to be measured. Also good.

The second optical system OSc-2 is arranged between the diaphragm DI and the optical waveguide OP, and is arranged in the optical waveguide OP so that each principal ray of each light beam emitted from the aperture surface of the diaphragm DI is parallel to the optical axis. It is an optical element that allows light to enter. That is, the second optical system OSc-2 is an image-side telecentric relay lens, and is composed of, for example, one lens group Grf.

The measurement optical system SSc used in the color luminance meter Dc in the third embodiment is similar to the measurement optical system SSa used in the color luminance meter Da in the first embodiment. It is possible to reduce the amount of light loss caused by having a large incident angle, and the light collection efficiency is good. The measurement optical system SSc can achieve uniform measurement sensitivity with sharp edges, and can guide a large amount of light even with a relatively small measurement diameter. Therefore, the measurement optical system SSc can guide a larger amount of light from the object to be measured Ob to the light receiving section 1 . The measurement optical system SSc is less susceptible to unevenness on the measurement surface.

Since such a measurement optical system SSc is used, the color luminance meter Dc in the third embodiment has the same effects as the color luminance meter Da in the first embodiment.

(Fourth to Sixth Embodiments)
Next, another embodiment will be described. FIG. 6 is a block diagram showing the configuration of a colorimeter according to fourth to sixth embodiments.

The first to third embodiments are color luminance meters Da, Db, and Dc using measurement optical systems SSa, SSb, and SSc, respectively. Colorimeters Dd, De, and Df using optical systems SSa, SSb, and SSc, respectively.

For example, as shown in FIG. 6, the colorimeter Dd in such a fourth embodiment includes a measurement optical system SSa, a light receiving unit 1, a control processing unit 2b, an input unit 3, an output unit 4, An IF section 5 and an illumination section 7 are provided. The measurement optical system SSa, the light receiving unit 1, the input unit 3, the output unit 4, and the IF unit 5 in the colorimeter Dd of the fourth embodiment are the measurement optical system SSa in the color luminance meter Da of the first embodiment. , the light receiving section 1, the input section 3, the output section 4, and the IF section 5, the description thereof will be omitted.

The illumination unit 7 is a device that irradiates the object to be measured Ob with illumination light in a predetermined geometry. and an illumination optical system for irradiating the object to be measured Ob with the light emitted from the unit as illumination light in the predetermined geometry. Although FIG. 6 shows a 45°:0° geometry as an example, the geometry is not limited to this and may be arbitrary.

The control processing unit 2b controls each unit 1, 3 to 5, 7 of the colorimeter Dd according to the function of each unit, and controls the entire color luminance meter Dd. Then, the control processing unit 2b measures the light from the object to be measured Ob with the measurement optical system SSa and the light receiving unit 1 according to the instruction received by the input unit 3, and based on the electric signal output from the light receiving unit 1, to obtain the color of the object to be measured Ob, and output the obtained color of the object to be measured Ob to the output unit 4 . Further, the control processing unit 2b outputs the determined color of the object to be measured Ob from the IF unit 5 as necessary. In this embodiment, the control processing unit 2b obtains the color of the object to be measured Ob from the X signal, Y signal and Z signal output from the light receiving unit 1 by a known technique. The control processing unit 2b is configured with, for example, a microprocessor.

In the colorimeter Dd according to the fourth embodiment, the illumination unit 7 illuminates the object to be measured Ob with illumination light, and the reflected light is incident on the measurement optical system SSa. Light (here, reflected light) from the object to be measured Ob is guided by the measurement optical system SSa in the same manner as in the first embodiment, received by the light receiving unit 1, and converted into an X signal, a Y signal, and a Z signal by the light receiving unit 1. It is photoelectrically converted as a signal. The light receiving section 1 outputs these X, Y and Z signals to the control processing section 2b, and the control processing section 2b obtains the color of the object to be measured Ob from these X, Y and Z signals. The color of the measured object Ob is output to the output unit 4 .

The measurement optical system SSa used in the colorimeter Dd of the fourth embodiment has the same effects as those of the first embodiment. Since such a measurement optical system SSa is used, the colorimeter Dd in the fourth embodiment can improve the SN ratio and perform colorimetry with higher accuracy. The colorimeter Dd is particularly advantageous for measuring low luminance regions. In addition, the colorimeter Dd can have a smaller measurement diameter and an improved spatial resolution.

For example, as shown in FIG. 6, the colorimeter De in the fifth embodiment includes a measurement optical system SSb, a light receiving section 1, a control processing section 2b, an input section 3, an output section 4, and an IF section 5. and an illumination unit 7 . The light receiving unit 1, the input unit 3, the output unit 4 and the IF unit 5 in the colorimeter De of the fifth embodiment correspond to the light receiving unit 1, the input unit 3 and the output unit 4 in the color luminance meter Da of the first embodiment. and the IF unit 5, so the description thereof will be omitted. Since the measurement optical system SSb in the colorimeter De of the fifth embodiment is the same as the measurement optical system SSb in the color luminance meter Db of the second embodiment, description thereof will be omitted. The control processing unit 2b and the lighting unit 7 in the colorimeter De of the fifth embodiment are the same as the control processing unit 2b and the lighting unit 7 in the color luminance meter Dd of the fourth embodiment, respectively, so description thereof will be omitted. do.

The measurement optical system SSb used in the colorimeter De of the fifth embodiment has the same effects as those of the second embodiment. Since such a measurement optical system SSb is used, the colorimeter De in the fifth embodiment has the same effect as the color luminance meter Dd in the fourth embodiment.

The colorimeter Df in the sixth embodiment includes, for example, as shown in FIG. and an illumination unit 7 . The light receiving unit 1, the input unit 3, the output unit 4 and the IF unit 5 in the colorimeter Df of the sixth embodiment correspond to the light receiving unit 1, the input unit 3 and the output unit 4 in the color luminance meter Da of the first embodiment. and the IF unit 5, so the description thereof will be omitted. The measurement optical system SSc in the colorimeter Df of the sixth embodiment is the same as the measurement optical system SSc in the color luminance meter Dc of the third embodiment, so description thereof will be omitted. The control processing unit 2b and the illumination unit 7 in the colorimeter Df of the sixth embodiment are the same as the control processing unit 2b and the illumination unit 7 in the color luminance meter Dd of the fourth embodiment, respectively, so description thereof will be omitted. do.

The measurement optical system SSc used in the colorimeter Df of the sixth embodiment has the same effects as those of the third embodiment. Since such a measurement optical system SSa is used, the colorimeter Df in the sixth embodiment has the same effect as the color luminance meter Dd in the fourth embodiment.

In the first to sixth embodiments described above, the image-side numerical aperture NA1 in the second optical systems OSa-2, OSb-2, and OSc-2 in the measurement optical systems SSa to SSc The numerical aperture of the fiber OP may be greater than or equal to NA2 (NA1≧NA2). In such measurement optical systems SSa to SSc, since NA1≧NA2, part of the light emitted from the measurement optical systems SSa to SSc cannot propagate through the optical waveguide (bundle fiber) OP, resulting in a light amount loss. However, as can be seen from the above description using FIGS. 2C and 7B, the loss amount of the light amount loss that occurs can be reduced compared to before. The measurement optical systems SSa to SSc in these embodiments are effective when NA1≧NA2.

Although this specification discloses various aspects of the technology as described above, the main technologies thereof are summarized below.

A measurement optical system according to one aspect includes a diaphragm, an optical waveguide that guides incident light, and a first optical system that is arranged on the object side of the diaphragm and forms an optical image from a measurement target on an aperture surface of the diaphragm. A second optical system disposed between the optical system, the diaphragm, and the optical waveguide, and configured to cause each principal ray of each light beam emitted from the aperture surface of the diaphragm to enter the optical waveguide so as to be parallel to the optical axis. and a system.

In such a measurement optical system, the first optical system forms an intermediate image by forming an optical image from the object to be measured on the aperture surface of the diaphragm, and the second optical system emits light from the aperture surface of the diaphragm. Each principal ray of each luminous flux is made incident on the optical waveguide so as to be parallel to the optical axis. Therefore, the optical system for measurement can reduce the loss of light amount caused by the off-axis light flux having a large incident angle, and has good light collection efficiency. Since the optical system for measurement forms the intermediate image, uniform measurement sensitivity with sharp edges can be achieved, and a large amount of light can be guided even with a relatively small measurement diameter. Therefore, the measurement optical system can guide a larger amount of light from the object to be measured to the light receiving section.

In another aspect, in the measurement optical system described above, the first optical system has a positive refractive power, and forms an optical image from the object to be measured on the aperture surface of the diaphragm so as to be telecentric on the object side. It consists of two first and second lens groups that allow the

Since such a measurement optical system does not have an image forming relationship due to the second optical system, unlike the double-telecentric system, it is less likely to be affected by unevenness on the measurement surface. In the measurement optical system, since the first optical system is composed of two lens groups, the first and second lens groups, a larger amount of light can be collected, and chromatic aberration can be easily corrected as necessary.

In another aspect, in the measurement optical system described above, the first optical system has a positive refractive power, and forms an optical image from the object to be measured on the aperture surface of the diaphragm so as to be telecentric on the object side. It consists of one lens group that allows

Such a measurement optical system is less susceptible to unevenness on the measurement surface for the same reason as in the above embodiment. The measurement optical system can be constructed more simply because the first optical system is composed of one lens group.

In another aspect, in the above-described measuring optical system, the image-side numerical aperture NA1 in the second optical system is equal to or greater than the numerical aperture NA2 in the optical waveguide (NA1≧NA2).

Although such a measurement optical system causes a loss of the amount of light, the loss amount of the loss of the amount of light that occurs can be reduced compared to before.

A color luminance meter according to another aspect uses any one of the measurement optical systems described above.

Since such a color luminance meter uses any one of the optical systems for measurement described above, a larger amount of light can be guided from the object to be measured to the light receiving section. Therefore, the color luminance meter can improve the SN ratio (Signal-to-Noise ratio) and perform colorimetry with higher accuracy. The color luminance meter is particularly advantageous for measuring low luminance regions. In addition, the color luminance meter can have a smaller measurement diameter and can improve the spatial resolution.

A colorimeter according to another aspect uses any one of the measurement optical systems described above.

Since such a colorimeter uses any one of the optical systems for measurement described above, a larger amount of light can be guided from the object to be measured to the light receiving section. Therefore, the colorimeter can improve the SN ratio and measure colors with higher accuracy. In particular, it is advantageous for measurement of low luminance regions. In addition, the colorimeter can have a smaller measurement diameter and an improved spatial resolution.

This application is based on Japanese Patent Application No. 2017-117588 filed on June 15, 2017, the content of which is included in the present application.

While embodiments of the present invention have been illustrated and described in detail, this is done by way of illustration and example only, and not limitation. The scope of the invention should be construed by the language of the appended claims.

Although the present invention has been adequately and fully described above through embodiments with reference to the drawings in order to express the present invention, modifications and/or improvements to the above-described embodiments can easily be made by those skilled in the art. It should be recognized that it is possible. Therefore, to the extent that modifications or improvements made by those skilled in the art do not depart from the scope of the claims set forth in the claims, such modifications or improvements do not fall within the scope of the claims. is interpreted to be subsumed by

ADVANTAGE OF THE INVENTION According to this invention, the optical system for a measurement which light-guides the light from to-be-measured object to a light-receiving part, the color luminance meter using the same, and the colorimeter using the same can be provided.

Claims (6)

Aperture and
an optical waveguide for guiding incident light;
a first optical system arranged on the object side of the diaphragm for forming an optical image from a measurement target on an aperture plane of the diaphragm;
An image-side telecentric second optical waveguide arranged between the diaphragm and the optical waveguide, and made incident on the optical waveguide so that the center of each beam emitted from the aperture surface of the diaphragm is parallel to the optical axis. an optical system;
Optical system for measurement. The first optical system has a positive refractive power and consists of two first and second lens groups that form an optical image from the object to be measured on the aperture surface of the aperture so as to be telecentric on the object side.
The optical system for measurement according to claim 1. The first optical system has a positive refractive power and consists of one lens group that forms an optical image from the object to be measured on the aperture surface of the aperture so as to be telecentric on the object side.
The optical system for measurement according to claim 1. The image-side numerical aperture of the second optical system is equal to or greater than the numerical aperture of the optical waveguide,
The measurement optical system according to any one of claims 1 to 3. A color luminance meter using the measurement optical system according to any one of claims 1 to 4. A colorimeter using the measurement optical system according to any one of claims 1 to 4.

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