JPH0651812U - 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 an inexpensive structure without including a movable part. [Structure] A plurality of annular light flux generating means 53, 54 concentric with the optical axis, which are annular around the optical axis of the optical system 37 and converge at one point on the optical axis at different angles with respect to the optical axis. And a mask plate 61 for allowing light to selectively enter the optical fibers 58 and 59 of the plurality of annular light flux generating means. If the annular light flux generating means is selected by sliding the mask plate 61, the angle of the illumination light focused on one point on the optical axis changes with respect to the optical axis, so the position of the focused point is kept at a fixed position. The incident angle of illumination light can be changed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an image processing type measuring machine for measuring the size and shape of a measured object from an image of the measured object obtained by an optical system. Specifically, an illuminating device that illuminates the DUT from a direction that is tilted with respect to the optical axis of the optical system, and in particular can clearly draw shadows such as the edges of the DUT. Regarding the improvement of.

[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, and visual 3D In measuring machines and the like, the illumination of the object to be measured plays a very 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 the illumination light is applied to the object to be measured almost directly above the object to be measured. However, the vertical 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 a display device.

Therefore, as a solution to this, by illuminating the object to be measured with illumination light from a direction inclined 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. A method that makes it possible is 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, 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 with respect 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 object to be measured has a relatively shallow cylindrical edge, such as a coin, the shadow of the edge will be clear over the entire circumference due to the relationship between the depth of the edge and the irradiation angle of the illumination light. Can not be described in. As a result, the image depicted on the display device loses the stereoscopic effect, and it becomes difficult to accurately measure the size and shape of the measured object.

Therefore, the present applicant has previously proposed JP-A-2-236405 as a solution to such a problem. This is because the support base is provided with shape recognition means for recognizing the shape of the object to be measured, and includes a movable mirror supported so as to be tiltable. The structure is such that an illuminating means for irradiating the illuminating light is provided so as to be capable of moving 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 JP-A-2-236405, since the tilt angle of the movable mirror is changed by the angle changing means, the irradiation angle of the illumination light with respect to the object to be measured can be changed. However, since there is a movable mirror on the illumination side, that is, because there is a movable portion, there is a problem in that the vibration accompanying the tilting movement of the movable mirror affects the optical system and reduces the measurement accuracy.

Further, for example, when the illumination light is emitted from the periphery of the shallow cylindrical edge portion of the object to be measured in order to emphasize the shadow, the optical axis of the shape recognizing means is set as the center. Since it is necessary to dispose a plurality of movable mirrors on the same circumference, 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 lighting means, which is structurally complicated. However, there is a disadvantage that the size of the device is increased, and the cost is increased.

An object of the present invention is to solve such a conventional problem, and to change the illumination angle of the illumination light with respect to the object to be measured without including a movable part and with a simple structure. An object is to provide an image processing type measuring machine.

[0010]

[Means for Solving the Problems]

 Therefore, the image processing type measuring machine of the present invention is an image processing type measuring machine for measuring the size and shape of the measured object from the image of the measured object obtained by the optical system, and the optical axis of the optical system. A plurality of annular light flux generating means, which are circular around the center of the optical axis and condense at different points with respect to the optical axis at one point on the optical axis, are arranged concentrically with the optical axis. Switching means for selectively activating the luminous flux generating means is provided.

[0011]

[Action]

 When one of the plurality of annular light flux generating means arranged concentrically with the optical axis is selectively made effective by the switching means, only the illumination light from the selected annular light flux generating means is circular. It is condensed in a ring shape and at one point on the optical axis. At this time, since the illumination light from the plurality of annular light flux generating means is configured to be converged at one point on the optical axis at different angles with respect to the optical axis, the annular light flux generation effective by the switching means is generated. If is selected, the incident angle of the illumination light at the focal point fixed position is changed while the focal point of the illumination light is kept at the fixed position on the optical axis. Therefore, the illumination light can be emitted at an appropriate angle according to the shape of the edge of the DUT, and the image of the edge of the DUT can be clearly drawn without impairing the stereoscopic effect. it can.

[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 table 21 toward the front, a table 22 for mounting an object 25 to be measured is installed on the upper surface. The stage 22 is composed of an XY table that is movable in two orthogonal directions in the 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 which 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 image forming lens 35 provided coaxially with the objective lens 34, and an image forming lens 35 provided coaxially with the image forming 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.

As shown in FIG. 2, an elevating shaft 42 is vertically slidably supported inside the support frame 31 via a holding block 41 provided in the support frame 31. A pinion 44, which meshes with a rack 43 formed along the longitudinal direction of the elevating shaft 42, is rotatably supported inside the holding block 41. A motor 46 is connected to the shaft 45 of the pinion 44. As a result, when the motor 46 is driven, the lifting shaft 42 slides in the vertical direction via the pinion 44 and the rack 43. A ring-shaped holding ring 52 is attached to the lower end of the lifting shaft 42 via an L-shaped bracket 51 coaxially with the optical axis of the optical system 37.

Inside the holding ring 52, two circles having an annular shape centered on the optical axis and converging at a point P on the optical axis at different angles θ _{1 and} θ ₂ with respect to the optical axis. The annular light beam generating means 53, 54 are arranged concentrically with the optical axis, and a through hole 55 is formed on one side above them. As shown in FIGS. 3 and 4, each of the annular light flux generating means 53, 54 has a ring-shaped member 56, 57 having an annular space therein and a state in which the ring-shaped members 56, 57 are bundled in the annular space. And is composed of a plurality of optical fibers 58 and 59. The tips of the optical fibers 58 and 59 are arranged in an annular shape one by one along the lower surfaces of the ring-shaped members 56 and 57, and the illumination light therefrom is focused on one point on the optical axis. It is arranged at such an angle.

Both the optical fibers 58 and 59 are bundled concentrically into a single tube 60. A light source 62 is arranged opposite to the tip of the tube 60, and both and one of the fibers 58 and 59 are selectively made effective between them (that is, the light from the light source 62 is made effective). A mask plate 61 as a switching means is slidably interposed. As shown in FIG. 5, the tip of the tube 60 is bundled so that the optical fiber 58 is located outside and the optical fiber 59 is located inside.

As shown in FIG. 6, the mask plate 61 is provided with a circular light transmitting portion 61 A having a size corresponding to the circle formed by the both optical fibers 58 and 59 at the first switching position A. At the second switching position B, a circular light transmitting portion 61B having a size corresponding to the circle formed by the optical fiber 59 is paired with the circle formed by the optical fiber 58 at the third switching position C. An annular light transmission portion 61C having a corresponding size and an inner diameter corresponding to the circle formed by the optical fiber 59 is formed. The other parts are shielded from light.

The image display device 90 controls the drive of the motor 46 and the CRT 91, switches the annular light flux generating means 53 and 54, and outputs a signal from the CCD camera 36 to the CRT 91. It is composed of a control device 92 to be displayed on. 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 and 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 output from the annular light flux generating means 53, 54 is reflected by the object 25 to be measured on the optical axis, and then is passed through the objective lens 34 and the imaging lens 35 to the CCD camera 36. It is incident. Here, after being converted into an electric signal, it is 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.

For example, when the annular light flux generating means 54 is used and the illumination light is applied to the object to be measured 25 at an angle of θ ₂ with respect to the optical axis, the object to be measured 25 is measured. When the shadow of the edge portion of No. 3 is not clearly displayed on the CRT 91, the mask plate 61 is slid to the third switching position C. Then, the light from the light source 62 is incident only on the optical fiber 58 of the annular light flux generating means 53, and this time, the illumination light is applied to the DUT 25 at an angle of θ ₁ with respect to the optical axis. It

As a result, the illumination light is irradiated at a more inclined angle with respect to the object to be measured 25 while the converging point of the illumination light is kept at a fixed position. Images such as edges can be clearly drawn without impairing the stereoscopic effect. For example, if the edge of the DUT 25 is shallow, the incident angle of the illumination light with respect to the DUT 25 becomes smaller by increasing the inclination angle θ of the illumination light with respect to the optical axis. The shadow of the edge can be clearly drawn.

Therefore, according to the present embodiment, a plurality of annular rings having optical fibers 58 and 59 that are annular around the optical axis and converge at one point on the optical axis at different angles with respect to the optical axis. A mask plate for arranging the light flux generating means 53, 54 concentrically with the optical axis and for selectively making light incident on the optical fibers 58, 59 of the plurality of annular light flux generating means 53, 54. Since 61 is slidably provided, the light can be selectively incident on the optical fibers 58 and 59 only by sliding the mask plate 61.

Then, since the incident angle of the illumination light at the position of the focal point 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 object to be measured 25 without changing. Therefore, the illumination light can be emitted at an appropriate angle according to the shape of the edge portion of the DUT 25, and the image of the edge portion 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 constituted only by the annular light flux generating means 53, 54, the mask plate 61 and the light source 62, The number of parts can be reduced, which can contribute to a reduction in the number of assembly steps. However, since there is no movable part on the illumination side, the vibration due to the movement of the movable part is not given to the optical system, and high precision measurement can be guaranteed.

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, instead of using the optical fibers 58 and 59 of the annular light flux generating means 53 and 54 as one tube 60, as shown in FIG. 7, they are separated from each other and light is selectively incident on them. You may do it.

Further, as the annular light flux generating means 53, 54, as shown in FIG. 8, a plurality of optical fibers 58, 59 are divided into a plurality of sections, for example, an angle range of 90 degrees is defined as one section. The light quantity can be easily adjusted by dividing the light source into four sections and independently controlling the turning on and off of the light source for introducing light into the optical fiber in each section. Further, instead of the optical fibers 58 and 59, light emitting elements such as light emitting diodes may be arranged in one row or a plurality of rows along the lower surface of the ring-shaped members 56 and 57. By doing so, it is possible to easily turn on and off the respective light emitting elements, so that there is an advantage that the light quantity of the annular light flux generating means 53, 54 can be finely adjusted.

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.

[0031]

[Effect of device]

 As described above, according to the image processing type measuring instrument of the present invention, it is possible to change the illumination angle of the illumination light with respect to the DUT with a simple structure without including a movable part.

[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 an annular light flux generating means.

FIG. 4 is a view of the annular light flux generating means of FIG. 3 as seen from below.

FIG. 5 is a diagram showing a tip of an optical fiber.

FIG. 6 is a diagram showing the mask plate of FIG. 3;

FIG. 7 is a perspective view showing another example of the annular light flux generating means.

FIG. 8 is a perspective view showing still another example of the annular light flux generating means.

[Explanation of symbols]

 10 image processing type measuring machine 25 object to be measured 37 optical system 53, 54 annular light beam generating means 58, 59 optical fiber 61 mask plate (switching 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 has an annular shape around the optical axis of the optical system. In addition, a plurality of annular light flux generating means for converging light at different points with respect to the optical axis are arranged concentrically with the optical axis at one point on the optical axis, and the plurality of annular light flux generating means are selectively effective. An image processing type measuring machine characterized by comprising a switching means.