JPH0571707U - Image processing type measuring machine - Google Patents

Abstract

(57) [Summary] [Object] To provide an image processing type measuring instrument capable of changing the angle of illumination light with respect to an object to be measured with a simple and inexpensive structure. The light generating means 46 and the light generating means 46 refract and illuminate the illuminating light generated from the light generating means 46 in a centripetal direction toward the optical axis of the optical system 37 and condense on the optical axis. The ring-shaped lens 51 that refracts the illumination light at different angles according to the relative position in the optical axis direction, and the light generation means 46 and the ring-shaped lens 51 are moved differentially while holding the focal point at a fixed position. And drive means 68. Since the relative position of the light generating means 46 and the ring-shaped lens 51 is changed only by moving them differentially, the incident angle at that point can be changed while keeping the condensing point at a fixed position.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an image processing type measuring machine. Specifically, in an image processing type measuring instrument that measures the size and shape of the measured object from the image of the measured object obtained by the optical system, illuminate from a direction inclined at a predetermined angle with respect to the optical axis of the optical system. The present invention relates to an improvement of an illumination device that irradiates light on an object to be measured, and in particular, makes it possible to clearly draw shadows such as edges of the object to be measured.

[0002]

[Background technology]

 An image processing type measuring instrument that optically magnifies the measurement site of the DUT using a magnifying optical system and measures the dimensions and shape of the DUT from the magnified image, such as a tool microscope, projector, visual three-dimensional In measuring machines and the like, illumination of an object to be measured plays an extremely important role in obtaining a magnified image of the object to be measured.

Conventionally, as an illumination system in an image processing type measuring instrument, a vertical epi-illumination system is known, in which illumination light is irradiated to an object to be measured from almost directly above the object to be measured. However, this vertical epi-illumination method is often used when measuring an object to be measured that has a relatively simple shape, and the object to be measured has a complicated shape, for example, an object to be measured that has many edge portions. When measuring (step-like objects), the shadow of the edge may not be clearly depicted on the display device.

Therefore, as a solution to this, by illuminating the object to be measured with illumination light from a direction tilted at a predetermined angle with respect to the optical axis of the magnifying optical system, the shadow of the edge portion can be clearly detected. Such a method has been proposed. For example, the technical idea is disclosed in US Pat. No. 4,567,551. This is a method in which illumination light is output from a light source in a substantially horizontal direction, and the illumination light is reflected obliquely downward by a fixed mirror, and then refracted by a glass plate or the like to irradiate the DUT.

However, even in this case, since the irradiation angle of the illumination light to the object to be measured is constant, the image of the edge portion cannot be clearly drawn on the display device depending on the shape of the edge portion. For example, if the DUT has a shallow cylindrical edge portion such as a coin, the shadow of the edge portion cannot be clearly drawn. Therefore, the image depicted on the display device loses the stereoscopic effect, and it becomes difficult to accurately measure the size and shape of the object to be measured.

Therefore, the present applicant has previously proposed JP-A-2-236405 as a solution to such a problem. This is provided with a shape recognition means for recognizing the shape of the object to be measured on the support base, and also includes a movable mirror supported so as to be tiltable. The structure is such that an illuminating means for illuminating the illuminating light is provided so as to be able to move up and down with respect to the shape recognizing means, and an angle changing means for changing the tilt angle of the movable mirror in association with the raising and lowering of the illuminating means.

[0007]

[Problems to be solved by the device]

 In the above-mentioned Japanese Patent Laid-Open No. 2-236405, the irradiation angle of the illumination light to the object to be measured can be changed by the inclination angle of the movable mirror of the illumination means. However, for example, when illuminating light from around the cylindrical edge of a DUT to emphasize the shadow of the shallow cylindrical edge of the DUT, the illumination should be on the same circle around the optical axis of the shape recognition means. Since it is necessary to dispose a plurality of movable mirrors at the same time, there is a drawback that the number of parts increases and the number of assembling steps increases.

Moreover, with respect to the angle changing means for changing the tilt angle of the movable mirror, the tilt angles of the plurality of movable mirrors have to be controlled simultaneously with the ascending / descending of the illumination means. However, there is a drawback in that the device becomes complicated, the device becomes large in size, and the cost is increased.

It is an object of the present invention to provide an image processing type measuring machine which solves such a conventional problem, has a small number of parts, and can be simply and inexpensively constructed. ..

[0010]

[Means for Solving the Problems]

 Therefore, the image processing type measuring instrument of the present invention is an image processing type measuring instrument for measuring the size and shape of the measured object from the image of the measured object obtained by the optical system. Light generating means for generating illumination light in a centripetal direction toward the optical axis, concentric with the optical axis, refracting the illumination light from the light generating means and condensing it on the optical axis, and A ring-shaped lens that reflects the illumination light from the light generating means at different angles according to the relative position in the optical axis direction with the light generating means, and the light generating means so that the converging point is held at a fixed position. And a driving means for differentially moving the ring-shaped lens along the optical axis direction.

[0011]

[Action]

 If the image of the object to be measured obtained by the optical system is not clear, the driving means is driven. Then, the light generating means and the ring-shaped lens are differentially moved along the optical axis direction of the optical system. As a result, the relative position of the light generating means and the ring-shaped lens in the optical axis direction changes, so that the illumination light is converged at the focal point while the focal point is kept at a fixed position on the optical axis. The incident angle of light is changed. Therefore, it is possible to change the incident angle of the illumination light at the focal point position without changing the light amount of the illumination light at the fixed position. That is, the illumination light can be emitted at an appropriate angle according to the shape of the edge of the object to be measured, so that the image of the edge of the object to be measured can be clearly drawn without impairing the stereoscopic effect.

[0012]

【Example】

 Preferred embodiments of the image processing type measuring instrument of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an image processing type measuring machine of this embodiment. The image processing type measuring machine 10 is roughly composed of a microscope 20 which is a tool microscope and an image display device 90.

The microscope 20 includes a support 21 having an L-shaped side surface. On a base portion 21A that protrudes from the lower part of the front surface of the support base 21 toward the front, a mount base 22 on which an object 25 to be measured is mounted is installed. The stage 22 is composed of an XY table that is movable in two orthogonal axes in a horizontal plane, that is, in the left-right direction (X-axis direction) and the front-back direction (Y-axis direction), and in each axial direction. The moving amount can be set or measured by the X-axis micrometer head 23 and the Y-axis micrometer head 24.

A vertical movement guide 27 having a vertical movement knob 26 is provided on the upper front surface of the support base 21. The vertical movement guide 27 supports a side-U-shaped support frame 31 that is vertically movable via a rack, a pinion, or the like (not shown) when the vertical movement knob 26 is rotated. At the front open end of the support frame 31, columnar bodies 32 are respectively interposed at the left and right ends of the support frame 31 to reinforce the support frame 31, and the open side of the support frame 31 has a planar U-shaped cover. 33 can be attached.

A magnifying optical system 37 is provided at the center of the support frame 31. The magnifying optical system 37 includes an objective lens 34 protruding below the support frame 31, an imaging lens 35 provided coaxially with the objective lens 34, and an imaging lens 35 provided coaxially with the imaging lens 35. It is composed of a CCD camera 36 protruding above 31. The image display device 90 is connected to the CCD camera 36 via a wiring cord 38.

Inside the support frame 31, as shown in FIG. 2, a pair of lift shafts 42 and 43 are supported slidably in the vertical direction via a holding block 41 provided in the support frame 31. Has been done. At the lower end of the elevating shaft 43, a ring-shaped light generating means 46 for generating illumination light in a centripetal direction toward the optical axis of the optical system 37 via a bracket 44 is connected to the optical axis of the optical system 37. They are arranged concentrically. As shown in FIG. 3, the light generating means 46 includes a ring-shaped member 47 and a plurality of optical fibers 48 that generate illumination light from the inner peripheral surface of the ring-shaped member 47 toward the optical axis in a centripetal manner. It consists of The optical fibers 48 are accommodated in a ring shape inside the ring-shaped member 47 in a state in which a plurality of optical fibers are bundled, and each end face is aligned and arranged one by one along the inner peripheral surface of the ring-shaped member 47. There is.

At the lower end of the elevating shaft 42, a ring-shaped lens 51 is attached concentrically with the optical axis of the optical system 37, and a belt-shaped mask 52 is provided at the inner focal position of the ring-shaped lens 51. It is installed. The ring-shaped lens 51 refracts the illumination light from the light generation means 46 toward the inside and condenses it on the optical axis, and according to the relative position of the light generation means 46 in the optical axis direction. The illumination light from the light generating means 46 is refracted at different angles. A cover 54 that covers the upper portion of the ring-shaped lens 51 is attached to the upper surface of the light generating means 46. The cover 54 is formed with an escape hole 55 for the elevating shaft 42.

Inside the holding block 41, pinions 63 and 64 that mesh with racks 61 and 62 formed along the longitudinal direction of the facing side surfaces of the pair of lifting shafts 42 and 43 are respectively rotatable. Supported by. A motor 66 is connected to a shaft 65 of the pinion 64, and a pinion 67 that meshes with the pinion 63 is provided. Here, the number of teeth n of these pinions 63, 64, 67 is n_1,n_2,n₃Is n ₂ > N₁> N₃Is set to. Therefore, if the elevating shafts 42 and 43 descend from the state of FIG. 2, the descending amount of the elevating shaft 43 becomes larger than the descending amount of the elevating shaft 42. Here, the light generating means 46 and the ring-shaped lens 51 are arranged so that the converging point is held at a fixed position by the lifting shafts 42, 43, the racks 61, 62, the pinions 63, 64, 67 and the motor 66. A drive unit 68 that differentially moves along the optical axis direction is configured.

The image display device 90 controls the driving of the CRT 91 and the motor 66, controls the light amount of the light generating means 46, and displays the signal from the CCD camera 36 on the CRT 91. It is composed of a control device 92. The control device 92 is provided with an operation unit 93 including a knob and a switch for performing each of the above controls at its front portion.

Next, the operation of this embodiment will be described. In the measurement, the X-axis and Y-axis micrometer heads 23, 24 of the stage 22 are set so that the object 25 to be measured placed on the stage 22 faces the objective lens 34. I'll do it. Further, the vertical movement knob 26 is rotated so that the measurement site of the object to be measured 25 is located at the focal position of the objective lens 34.

The illumination light, which is emitted from the light generating means 46 in a centripetal manner toward the optical axis, is refracted inward by the ring lens 51 and then reflected by the object to be measured 25 on the optical axis. It Then, the light is incident on the CCD camera 36 through the objective lens 34 and the imaging lens 35, converted into an electric signal here, and then input to the control device 92 of the image display device 90. As a result, the image of the DUT 25 is displayed on the CRT 91.

Here, when the image of the object to be measured 25 displayed on the CRT 91 is not clear, for example, when the shadow of the edge portion of the object to be measured 25 is not clear, the operation unit 93 of the control device 92 is used. Is operated to drive the motor 66 of the drive means 68. Then, the pair of lifting shafts 42, 43 are differentially moved via the pinions 63, 64, 67. At this time, for example, if the elevating shafts 42 and 43 are lowered, the lowering amount of the elevating shaft 43 is larger than the lowering amount of the elevating shaft 42. 46 is greatly lowered along the optical axis direction.

Then, as shown in the states of FIGS. 4A and 4B, the ring-shaped lens 51 guides the illumination light from the light generating means 46 to the inside according to the position in the optical axis direction with the light generating means 46. Since the light is refracted at different angles toward each other, the incident angle of the illumination light at the focal point is changed while the focal point on the optical axis is kept at a fixed position. Therefore, the illumination light can be emitted at an appropriate angle according to the shape of the edge portion of the object to be measured 25, and the image of the edge portion of the object to be measured 25 can be clearly drawn without impairing the stereoscopic effect. ..

For example, in the case where the edge of the DUT 25 is shallow, the incident angle of the illumination light to the DUT 25 becomes shallow when the inclination angle θ of the illumination light is made small. The shadow of the edge part of can be clearly drawn. Moreover, in any of the states of FIGS. 4A and 4B, the ring-shaped lens 51 focuses the illumination light from the light generating means 46 inward and at a fixed position on the optical axis. Therefore, the amount of illumination light for the object to be measured 25 does not change.

Therefore, according to the present embodiment, the light generating means 46 that emits the illumination light in a centripetal direction toward the optical axis of the optical system 37 is provided concentrically with the optical axis, and is located inward of the optical axis. A ring-shaped lens 51 that refracts the illumination light toward the inside to condense it on the optical axis and refracts the illumination light at different angles according to the position of the illumination light in the optical axis direction is provided. Since the driving means 68 for moving the ring-shaped lens 51 and the light generating means 46 in the optical axis direction so as to be held at the fixed positions is provided, the ring-shaped lens 51 and the light generating means are driven by the driving means 68. If the lens 46 is moved differentially, the relative position of the light generating means 46 and the ring lens 51 in the optical axis direction changes, so that the ring lens 51 moves the focal point to a fixed position on the optical axis. Kept in.

That is, since the incident angle of the illumination light at the focal point position is changed while the focal point is kept at the fixed position on the optical axis, the light amount of the illumination light with respect to the DUT 25 is changed. It is possible to change the angle of the illumination light with respect to the DUT 25 without changing. Therefore, the illumination light can be emitted at an appropriate angle according to the shape of the edge of the DUT 25, and the image of the edge of the DUT 25 can be drawn clearly without impairing the stereoscopic effect. it can.

Further, since the structure capable of irradiating the measurement site of the object to be measured 25 with the illumination light from the surroundings can be configured only by the light generating means 46, the ring-shaped lens 51 and the driving means 68, the number of parts is also increased. The number can be reduced, which can contribute to a reduction in the number of assembling steps. Moreover, with respect to the driving means 68, it is sufficient that the light generating means 46 and the ring-shaped lens 51 are differentially moved in the same direction, that is, they are differentially moved in the optical axis direction of the optical system 37. Since only the racks 61, 62 and the pinions 63, 64, 67 formed on the elevating shafts 42, 43 are required, the structure is simple and inexpensive.

Further, since the belt-shaped mask 52 is arranged at the inner focal position of the ring-shaped lens 51, the illumination side becomes telecentric, and even if the irradiation angle of the illumination light is changed, the uniformity of illumination is not impaired. There are advantages.

The present invention is not limited to the configuration of the above embodiment, and various improvements and design changes can be made without departing from the scope of the present invention.

For example, as the light generating means 46, as shown in FIG. 5, a plurality of optical fibers 48 are divided into a plurality of sections, and for example, an angle range of 90 degrees is divided into four sections, The light quantity can be easily adjusted by independently controlling the turning on and off of the light source that introduces light into the optical fiber in each section. Further, instead of the optical fiber 48, light emitting elements such as light emitting diodes may be arranged in a row or a plurality of rows along the inner peripheral surface of the ring-shaped member 47. By doing so, it is possible to easily turn on and off each light emitting element, which is advantageous in that the light quantity of the light generating means 46 can be finely adjusted.

Further, the driving means 68 is not limited to the one using the rack and the pinion described in the above embodiment, but it is possible to differentially move the pair of lifting shafts 42, 43 in the optical axis direction. It doesn't matter. Further, instead of the CCD camera 36, an image orthe like may be used.

Further, the image processing type measuring instrument according to the present invention is not limited to the one applied to the tool microscope as in the above-mentioned embodiment, but other types of optical measuring instruments such as a projector and a three-dimensional measuring instrument. It can also be applied to machines.

[0033]

[Effect of the device]

 As described above, according to the image processing type measuring instrument of the present invention, the number of parts is small, and the configuration can be simple and inexpensive.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main part of FIG.

FIG. 3 is a perspective view showing a light generating means.

FIG. 4 is a diagram for explaining a relationship between a light generating means and a ring lens.

FIG. 5 is a perspective view showing another example of the light generating means.

[Explanation of symbols]

 25 object to be measured 37 magnifying optical system 46 light generating means 51 ring-shaped lens 68 driving means

Claims (1)

[Scope of utility model registration request] 1. An image processing type measuring instrument for measuring the size, shape, etc. of an object to be measured from an image of the object to be measured obtained by an optical system, which is centripetal toward the optical axis of the optical system. Light generating means for generating illumination light, concentric with the optical axis, and refracting the illumination light from the light generating means to focus the light on the optical axis, and the optical axis direction with the light generating means. A ring-shaped lens for refracting the illumination light from the light generation means at different angles according to the relative position in the optical axis, and the light generation means and the ring-shaped lens for holding the condensing point at a fixed position. An image processing type measuring instrument comprising: a driving unit that differentially moves along a direction.