JP2012118194A - Optical measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical measuring instrument capable of more efficient transmitted illumination of a specimen, without large sizing of the whole instrument.SOLUTION: In this optical measuring instrument, a transmitted illumination panel 35 composed of a plurality of light-emitting diodes arranged in parallel is disposed on a stage 31 on which a specimen 12 is to be placed. When the size of the specimen 12 is measured, a controller 22 calculates the center location of the observation field of an object lens 32 on the stage 31 according to a moving amount of the stage 31. Then the controller 22, on the basis of the calculated center location and the size of the observation field of the object lens 32, controls lighting of each light-emitting diode so that only the light-emitting diodes forming the transmitted illumination panel 35 which are within the observation field of the object lens 32 emit light. This invention is applicable to the optical measuring instrument.

Description

  The present invention relates to an optical measuring instrument that can illuminate a test object more efficiently without enlarging the entire apparatus when transmitting the test object placed on a stage.

  2. Description of the Related Art Conventionally, optical measuring machines such as a measuring microscope, an image measuring machine, and a measuring projector are widely used for measuring the geometric dimension of a test object such as a part.

  In such an optical measuring machine, the stage on which the test object is placed and the center of the visual field observed by the observation optical system on the test object can be read is opposite to the observation optical system side of the stage. From the side, an illuminating device that transmits and illuminates the test object is provided.

  For example, in a vertical optical measuring machine in which the observation optical system is arranged in the vertical direction with respect to the stage, the illumination device is arranged on the lower side in the vertical direction of the stage, and the illumination light from the illumination device passes through the center of the stage. In order to achieve this, a through hole is provided along the optical axis of the illumination optical system (see, for example, Patent Document 1). Many optical measuring machines having through-holes on a stage are provided with a glass plate for placing a test object on the upper surface of the stage.

  There has also been proposed a microscope in which a light emitting panel for transmitted illumination is provided on the upper surface of the stage without providing a through hole in the stage (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 2002-18120

JP-A-8-146300

  However, with the above-described technique, it has been difficult to efficiently illuminate the test object without increasing the size of the entire apparatus.

  For example, in a vertical optical measuring machine, if a through hole is provided, the stage strength will decrease, so in order to compensate for the strength reduction, it is necessary to increase the thickness of the stage member. The device will also be heavy.

  In addition, a microscope with a light-emitting panel on the top surface of the stage emits light on the entire top surface of the stage, which not only increases power consumption, but also keeps areas that are not subject to observation of the test object, that is, areas outside the observation field of view. It was not efficient because it was illuminated.

  The present invention has been made in view of such a situation, and makes it possible to illuminate a test object more efficiently without increasing the size of the entire apparatus.

  The optical measuring instrument of the present invention irradiates the specimen with illumination light by irradiating illumination light to each stage on the stage on which the specimen is placed and the stage surface on which the specimen is placed. Detecting a position of an observation field of the observation optical system with respect to the stage, and an observation optical system that focuses light from the test object to form an image of the test object Based on the detection result by the position detection means and the position detection means, a plurality of areas on the stage surface so as to be illuminated by the illumination light with a predetermined size area including the observation field center of the observation optical system. Illumination control means for controlling irradiation of the illumination light by the illumination unit.

  According to the present invention, a test object can be illuminated more efficiently without increasing the size of the entire apparatus.

It is a figure which shows the structural example of one Embodiment of the optical measuring device to which this invention is applied. It is a figure which shows the more detailed structural example of a stage and a controller. It is a flowchart explaining an illumination process.

  Embodiments to which the present invention is applied will be described below with reference to the drawings.

[Configuration of optical measuring instrument]
FIG. 1 is a diagram showing a configuration example of an embodiment of an optical measuring machine to which the present invention is applied. In FIG. 1, the horizontal direction, the depth direction, and the vertical direction indicate the x direction, the y direction, and the z direction that are orthogonal to each other.

  For example, the optical measuring instrument 11 is a measuring instrument that measures the dimensions of an arbitrary part of the test object 12 that is a measurement target, and includes a measuring instrument main body 21 and a controller 22.

  The measuring machine main body 21 is provided with a stage 31 on which the test object 12 is placed, an objective lens 32 that collects light from the test object 12, and an eyepiece 33 for observing the test object 12. ing. Further, the stage 31 is provided with an origin switch 34 and a transmission illumination panel 35 for transmitting illumination of the test object 12 from the side opposite to the objective lens 32 side.

  Here, the origin switch 34 is composed of, for example, a stroke end sensor, and serves as a reference when detecting the position of the stage 31 on the xy plane, more specifically, the center position of the observation field of the objective lens 32 with respect to the stage 31. A switch that resets the position. The origin switch 34 may be a switch that is directly operated by the user. In such a case, the user operates the origin switch 34 to cause the optical measuring instrument 11 to recognize the reference position.

  When illumination light is irradiated from the transmitted illumination panel 35 to the test object 12, the light from the test object 12 is collected by an observation optical system including an objective lens 32, an eyepiece lens 33, a lens (not shown), and the like. It is illuminated and an image of the test object 12 is formed. Thereby, the user can observe the test object 12 from the eyepiece 33.

  Note that a camera may be provided in the measuring instrument main body 21 so that an observation image of the test object 12 captured by the camera is displayed on the controller 22.

  Further, a recognition sensor 36 for specifying the optical magnification of the objective lens 32 is provided in the vicinity of the objective lens 32 of the measuring machine main body 21.

  For example, the recognition sensor 36 reads out information on the objective lens 32 attached to the measuring machine main body 21 from the measuring machine main body 21 to identify the optical magnification of the objective lens 32, and magnification information indicating the obtained optical magnification. Is supplied to the controller 22. From this magnification information, the observation field of the observation optical system (objective lens 32), that is, the size of the region on the stage 31 that can be observed by the objective lens 32 can be specified. Hereinafter, the observation field of the objective lens 32 is assumed to be circular, and the radius of the observation field is referred to as radius R.

  The controller 22 controls the operation of the measuring machine main body 21 in accordance with a user operation. For example, the controller 22 transmits and illuminates only the region in the observation field of the objective lens 32 on the stage 31 based on the magnification information from the recognition sensor 36 and the center position of the observation field of the objective lens 32. Control the transmitted illumination panel 35. Moreover, the controller 22 measures the dimension between the designated parts of the test object 12 according to the operation of the user, and displays the measurement result on the display unit 37 including a liquid crystal display.

[Configuration of controller, etc.]
In more detail, the stage 31 and the controller 22 of FIG. 1 are configured as shown in FIG. In FIG. 2, the horizontal direction, the depth direction, and the vertical direction indicate the x direction, the y direction, and the z direction, respectively. In FIG. 2, the same reference numerals are given to the portions corresponding to those in FIG. 1, and description thereof will be omitted as appropriate.

  In the example of FIG. 2, the stage 31 mainly includes a stage pedestal 61, an x movable portion 62, a y movable portion 63, a transmitted illumination panel 35, and ground glass 64.

  The stage base 61 is fixed to the measuring machine main body 21, and an x movable portion 62 that is movable in the x direction is provided on the upper side of the stage base 61 in the figure. Further, on the upper side of the x movable portion 62 in the drawing, a y movable portion 63 that is movable in the y direction is provided.

  The x movable portion 62 and the y movable portion 63 move in the x direction and the y direction with respect to the stage base 61 and the x movable portion 62, so that the test object 12 placed on the stage 31 is also in the xy direction. Move to. That is, an arbitrary part of the test object 12 is observed by moving the test object 12 in a direction perpendicular to the optical axis of the objective lens 32 with respect to the objective lens 32 fixed to the measuring machine main body 21. Will be able to.

  Furthermore, on the upper side in the drawing of the y movable portion 63, for example, a plate-shaped transmissive illumination panel 35 made of a plurality of light emitting diodes arranged in the xy direction is provided. A plate-shaped ground glass 64 on which the test object 12 is placed is provided. By providing the ground glass 64 between the test object 12 and the transmission illumination panel 35, the illumination light from each light-emitting diode is diffused by the ground glass 64, and the illumination light irradiated on the test object 12 is uneven. Can be prevented. That is, it is possible to irradiate the test object 12 with illumination light having substantially uniform brightness.

  Here, the dimension of the transmitted illumination panel 35 in the xy direction is determined in consideration of the stroke (measurement range) in which the stage 31 can move in the xy direction with respect to the objective lens 32 and the size of the observation field of view of the objective lens 32. It is done. That is, the size of the transmission illumination panel 35 is determined in advance so that the observation field of the objective lens 32 can always be illuminated with illumination light regardless of the position of the stage 31.

  The illumination light emitted from the light emitting diodes constituting the transmissive illumination panel 35 may be any color light, but considering the fatigue of the eyes of the user and the reduction of chromatic aberration in the observation optical system, the illumination light is white. It is desirable to be monochromatic light such as light or green.

  Further, the light-emitting elements constituting the transmissive illumination panel 35 are not limited to light-emitting diodes, but may be other solid-state light-emitting elements, cold cathode discharge tubes, or the like. The solid-state light emitting element here includes a light emitting diode, a laser diode, an organic EL (Electro Luminescence), a plasma light emitting element, and the like. Further, the ground glass 64 may be any plate member as long as it can diffuse illumination light.

  The stage base 61 and the x movable portion 62 are provided with an encoder 65 and an encoder 66 that output signals in accordance with movement of the x movable portion 62 and the y movable portion 63 in the x direction and the y direction. For example, the encoder 65 and the encoder 66 are composed of linear encoders.

  In the example of FIG. 2, the encoder 65 is fixed to the stage pedestal 61 so that it is not located on the side surface of the stage pedestal 61 but is located substantially at the center of the stage pedestal 61, i. . Similarly, the encoder 66 is also fixed to the x movable portion 62 so as to be positioned at the approximate center of the x movable portion 62.

  Thus, in the stage 31, since the transmission illumination panel 35 is arrange | positioned directly under the ground glass 64 in which the to-be-tested object 12 is mounted, like the conventional optical measuring machine, the stage is used for illumination. There is no need to provide a through hole. For this reason, the encoder 65 and the encoder 66 can be disposed almost directly below the objective lens 32 to reduce the Abbe error. Thereby, the amount of movement of the stage 31 in the xy direction relative to the objective lens 32 can be detected more accurately.

  The encoder 65 and the encoder 66 are not limited to linear encoders, but may be any encoder that can detect the amount of movement of the stage 31 in the xy direction, such as a rotary encoder provided in a rotation mechanism such as a motor or a handle. It may be.

  The controller 22 includes a position calculation unit 67, an illumination area calculation unit 68, an illumination control unit 69, a measurement unit 70, and a display unit 37.

  Based on the signals output from the encoder 65 and the encoder 66, the position calculation unit 67 is the center of the observation field of the objective lens 32 in the xy coordinate system in which the x and y axes are parallel to the x and y directions. Calculate the coordinates of the position.

  For example, the xy coordinate system is a coordinate system having one end of ground glass 64 constituting the stage 31 as an origin. In this case, when the stage 31 moves in the xy direction, the objective lens 32 moves relative to the stage 31. Therefore, the center position of the observation field of the objective lens 32 on the surface of the ground glass 64 of the stage 31, that is, The coordinates of the center position of the observation field in the xy coordinate system change.

  The position calculation unit 67 detects the amount of movement of the stage 31 based on the signals from the encoder 65 and the encoder 66, and calculates the coordinates (Pos_X, Pos_Y) of the center position of the observation field of the objective lens 32 in the xy coordinate system. . Hereinafter, information indicating the coordinates (Pos_X, Pos_Y) of the center position of the observation field is referred to as position information.

  The illumination area calculation unit 68 calculates the radius R of the observation field of the objective lens 32 based on the magnification information from the recognition sensor 36, and based on the obtained radius R and the position information from the position calculation unit 67. Thus, the observation field region of the objective lens 32 is specified.

  The illumination area calculation unit 68 controls the illumination control unit 69 based on the result of specifying the observation field area on the stage 31. The illumination control unit 69 individually causes each light-emitting diode constituting the transmissive illumination panel 35 to emit light or extinguishes according to the control of the illumination area calculation unit 68. The measurement unit 70 acquires position information from the position calculation unit 67 in accordance with a user operation, calculates a distance (dimension) between designated parts of the test object 12, and a measurement result of the distance between parts Etc. are displayed on the display unit 37.

[Operation of optical measuring instrument]
Next, the operation of the optical measuring instrument 11 will be described.

  When the power source of the optical measuring instrument 11 is turned on and the user operates the huddle provided on the stage 31 to move the stage 31 to a predetermined position to turn on the origin switch 34, the optical measuring instrument 11 becomes xy. Reset the origin of the coordinate system. The stage 31 may be moved manually by a user through a handle operation, or the controller 22 may be electrically operated in accordance with a user operation.

  In addition, when the user places the test object 12 on the stage 31 and instructs to start measuring the distance between specific parts of the test object 12, the optical measuring instrument 11 performs measurement processing according to the user's operation. Do.

  Specifically, for example, when the user looks into the eyepiece lens 33, the user is informed of the region of the test object 12 within the observation field of view of the observation optical system (objective lens 32) and an arbitrary position of the test object 12. You can see the sight to specify the. The user moves the x movable portion 62 and the y movable portion 63 by operating a handle provided on the stage 31 so that a desired part of the test object 12 overlaps the center of the aim.

  Then, when the user instructs the start of measurement in a state where the desired part of the test object 12 is aimed, the position calculation unit 67 determines the observation field of view based on the signals output from the encoder 65 and the encoder 66. The coordinates (Pos_X, Pos_Y) of the center position are calculated.

  The measurement unit 70 acquires position information indicating coordinates (Pos_X, Pos_Y) from the position calculation unit 67 and sets the position of the acquired coordinates as the position of the starting point of the distance measurement of the test object 12.

  The measurement unit 70 also displays the coordinates (x ′, y ′) of the center position of the observation field of the objective lens 32 in the x′y ′ coordinate system with the origin of the distance measurement start point of the test object 12 as the origin. 37. Here, the x′y ′ coordinate system is a coordinate system in which the x ′ axis and the y ′ axis are parallel to the x axis and the y axis of the xy coordinate system, and only the position of the origin is different from the xy coordinate system.

  Therefore, for example, at the present time, the center position of the observation field of the objective lens 32 is at the starting point position of the distance measurement of the test object 12, so the coordinates (x ′, y) of the center position of the observation field are displayed on the display unit 37. '), (0, 0) is displayed.

  In addition, when the user moves the stage 31 and instructs distance measurement in a state where the distance measurement end point position on the test object 12 is aimed, the measurement unit 70 causes the distance measurement end point position of the test object 12 to be measured. The position information indicating the coordinates (Pos_X, Pos_Y) is acquired from the position calculation unit 67.

  Then, the measurement unit 70 calculates the distance from the start point to the end point based on the coordinates (Pos_X, Pos_Y) of the start point and end point of the distance measurement of the test object 12, and the display unit 37 uses the calculated distance as a measurement result. To display. Further, the measurement unit 70 also displays the coordinates (x ′, y ′) of the end point position of the distance measurement of the test object 12 in the x′y ′ coordinate system on the display unit 37.

  In this way, the optical measuring instrument 11 measures the distance between two points on the test object 12 in accordance with a user operation, and displays the measurement result. At this time, the optical measuring instrument 11 transmits light so that only the region in the observation field of view of the objective lens 32 on the stage 31 is continuously transmitted and illuminated by the illumination light, regardless of how the stage 31 is moved. The illumination of the test object 12 by the panel 35 is controlled.

  Next, with reference to the flowchart of FIG. 3, an illumination process that is a process in which the optical measuring instrument 11 controls the illumination by the transmission illumination panel 35 will be described. This illumination process is started when the optical measuring instrument 11 is turned on.

  In step S11, the position calculator 67 calculates the coordinates (Pos_X, Pos_Y) of the center position of the observation field of the objective lens 32 in the xy coordinate system based on the signals output from the encoder 65 and the encoder 66. Then, the position calculation unit 67 supplies coordinate information indicating the calculation result to the illumination area calculation unit 68.

  In step S <b> 12, the illumination area calculation unit 68 calculates the radius R of the observation field of the objective lens 32 based on the magnification information supplied from the recognition sensor 36.

  In step S <b> 13, the illumination area calculation unit 68 should be turned on among the light emitting diodes constituting the transmissive illumination panel 35 using the calculated observation field radius R and the position information from the position calculation unit 67. Identify the light emitting diode.

  Specifically, for example, the illumination area calculation unit 68 includes information specifying each light-emitting diode constituting the transmissive illumination panel 35 and coordinates (XL, YL) indicating the position of the light-emitting diode in the xy coordinate system. The associated position table is held in advance.

  Then, the illumination area calculation unit 68 refers to the position table and turns on (emits) a light emitting diode that satisfies the following expression (1) with the coordinates of the observation field indicated by the position information as (Pos_X, Pos_Y). A light emitting diode is used.

(XL-Pos_X) ² + (YL-Pos_Y) ² <R ² (1)

  In Equation (1), XL and YL are the x coordinate and the y coordinate of the arrangement position of the light emitting diodes constituting the transmissive illumination panel 35, and R indicates the radius of the observation field of the objective lens 32.

  Therefore, the light emitting diode at the position of the coordinates (XL, YL) satisfying the expression (1) illuminates the light emitting diode on the stage 31 in the observation visual field of the objective lens 32, that is, the region in the observation visual field. It is a light emitting diode that emits light.

  The illumination area calculation unit 68 uses the expression (1) to turn on the light emitting diodes within the observation field of the objective lens 32 among the light emitting diodes constituting the transmission illumination panel 35, and emit light that is outside the observation field. The diode should be turned off.

  In step S <b> 14, the illumination area calculation unit 68 controls the lighting control unit 69 based on the result of specifying the light emitting diodes to be lit, thereby controlling the lighting and extinguishing of the respective light emitting diodes constituting the transmissive lighting panel 35. .

  The illumination control unit 69 supplies a current signal according to the control of the illumination area calculation unit 68 to each light emitting diode constituting the transmissive illumination panel 35, and turns on or off the light emitting diode. Thereby, only the light emitting diode in the observation visual field of the objective lens 32 emits light, and the object 12 is transmitted and illuminated by the illumination light. Further, the light emitting diode located outside the observation field of the objective lens 32 does not emit light.

  In this way, when the lighting and extinguishing of the light emitting diodes of the transmissive illumination panel 35 are controlled, the process then returns to step S11 and the above-described processes are repeated. In other words, when the stage 31 is moved, the light emitting diodes are controlled to be turned on and off so that the light emitting diodes in the new observation field of the objective lens 32 are turned on. This illumination processing is continued until the optical measuring instrument 11 is turned off, such as during the above-described measurement processing.

  As described above, the optical measuring instrument 11 detects the movement of the stage 31 and is positioned in the observation field based on the center position of the observation field obtained from the detection result and the radius R of the observation field. Turn on only the light emitting diode.

  As described above, the illumination process for turning on only the light-emitting diodes in the observation visual field among the light-emitting diodes of the transmission illumination panel 35 is performed at the time of measuring the distance of the test object 12, so that the region to be noted of the test object 12 is notable. Can be illuminated efficiently. Moreover, the power consumption in the transmissive illumination panel 35 can also be reduced by preventing the light emitting diode from emitting light more than necessary.

  Furthermore, since only the necessary light emitting diodes are lit in the optical measuring instrument 11, heat generation due to illumination light or the like can be suppressed. Thereby, deformation | transformation of the stage 31 grade | etc., By thermal expansion can be suppressed, and the measurement precision of the distance of the to-be-tested object 12 can be improved.

  Further, since the optical measuring instrument 11 has a configuration in which a plurality of light emitting diodes are arranged side by side immediately below the ground glass 64 on which the test object 12 is placed, it is not necessary to provide a through hole for illumination in the stage 31. The strength of the stage 31 can be sufficiently secured. Therefore, the stage 31 can be made thinner than the conventional one, and as a result, the optical measuring instrument 11 can be downsized.

  In the above, an example in which the transmissive illumination panel 35 is provided on the stage 31 has been described. However, the transmissive illumination panel 35 may be provided anywhere as long as each light-emitting diode can illuminate each region of the stage 31. .

  Further, when the transmittance of the illumination light in each part of the test object 12 is obtained in advance, each of the lighting lights so that the amount of the illumination light transmitted through the test object 12 is uniform in each region You may make it adjust the light quantity of the illumination light of a light emitting diode.

  In such a case, for example, the illumination area calculation unit 68 controls the illumination control unit 69 so that the illumination light is emitted with an intensity corresponding to the transmittance of each part of the test object 12. The illumination control unit 69 emits illumination light from the light emitting diode with a desired intensity by adjusting the magnitude (amplitude) of the current signal supplied to the light emitting diode of the transmissive illumination panel 35 according to the control of the illumination area calculating unit 68. Let Thereby, the test object 12 can be observed in a better state.

  In addition, for example, the illumination region calculation unit 68 adjusts the intensity of the illumination light of the light emitting diode in the observation field so that the intensity of the irradiated illumination light increases as the position is closer to the center of the observation field of the objective lens 32. You may do it. Furthermore, the region of the stage 31 that is transmitted and illuminated does not necessarily have to be an observation field region of the objective lens 32, and may be a region having a predetermined size including the center of the observation field.

  Note that the present invention can be applied to an image measuring machine, a measuring projector, a microscope, and the like.

  The embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 11 Optical measuring machine, 12 Test object, 21 Measuring machine main body, 22 Controller, 31 Stage, 32 Objective lens, 35 Transmission illumination panel, 36 Recognition sensor, 64 Ground glass, 67 Position calculating part, 68 Illumination area calculating part, 69 Illumination Control unit, 70 measurement unit

Claims (6)

A stage on which the test object is placed;
A plurality of illumination units that transmit and illuminate the test object by irradiating illumination light to each region of the stage surface on which the test object is placed, and
An observation optical system that focuses light from the test object and forms an image of the test object;
Position detection means for detecting the position of the observation field of the observation optical system with respect to the stage;
Based on the detection result by the position detection means, a plurality of illumination units are provided so that a region of a predetermined size including the observation field center of the observation optical system on the stage surface is illuminated by the illumination light. An optical measuring device comprising: an illumination control unit that controls irradiation of the illumination light. Further comprising a calculation means for calculating the size of the observation field based on the optical magnification of the observation optical system,
The said illumination control means controls irradiation of the said illumination light by the said illumination part so that the area | region in the said observation visual field in the said stage surface may be illuminated with the said illumination light. Optical measuring machine. The optical measuring device according to claim 1, wherein the illumination unit is provided on the stage. The plate is provided with a plate-like diffusion part that diffuses the illumination light adjacent to the illumination part, and the test object is placed on the diffusion part. The optical measuring machine described. The optical measuring instrument according to claim 4, wherein the illumination unit is a solid-state light emitting element. The illumination control unit is configured to make the amount of the illumination light transmitted through each region of the test object substantially uniform based on the transmittance of the illumination light in each region of the test object obtained in advance. The optical measuring device according to claim 1, wherein a light amount of the illumination light from the illumination unit is controlled.

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