JPH07117369B2 - Table type measuring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a table-type length measuring device, and more particularly to improvement of a transillumination device in the length measuring device.

<< Prior Art >> As a length measuring device of this type, there is one conventionally disclosed in, for example, Japanese Patent Application Laid-Open No. 62-134505 proposed by the present applicant.

As shown in FIGS. 4 and 5, the translucent measurement table 104 on which the object to be measured W is placed and the object to be measured W on the measuring table 104 are illuminated from below by a large number of fluorescent lamps 131. And an observation optical system 120 for observing the object to be measured W from above, which is provided so as to be movable in the XY directions with respect to the measurement table 104 and positionally readable. It is configured to measure the object to be measured W based on the XY movement amount of the observation optical system 120.

In these figures, reference numeral 134 is a frequency converter of the fluorescent lamp 131, 150 is a monitor television for displaying an enlarged image by the observation optical system 120, and 117 is movably installed in the front-back (Y) direction with respect to the measurement table 104. The traveling rack 118 is a pedestal provided with the observation optical system 120 so as to be movable in the left and right (X) directions on the traveling rack 117, and 112 and 112 are drive transmission means for the pedestal 118 and the traveling rack 117, respectively. X via (not shown)
A drive handle that moves in the −Y direction, and 126 is a movement amount reading device that reads and outputs the movement amounts of the gantry 118 and the traveling rack 117.

<< Problems to be Solved by the Invention >> In the conventional example described above, the object to be measured W on the measurement table 104 is
Since the structure is such that a large number of fluorescent lamps 131 are illuminated from below, there are the following drawbacks.

When the object to be measured is a film original plate, the film original plate curls or expands and contracts due to the heat generated by the fluorescent lamp, and thus the measurement accuracy decreases. In particular, in the case of a circuit pattern on a printed wiring board or the like, it is necessary to capture an image at a high magnification, high illuminance is required, and heat generation is large.

Further, although the fluorescent lamps are arranged at a predetermined interval, unevenness in the illuminance distribution occurs due to the arrangement of the fluorescent lamps on the measurement table. In order to prevent the unevenness of the illuminance distribution, a light diffusing plate or the like is usually used, but it is difficult to obtain a completely uniform illuminance distribution. Since such unevenness of the illuminance distribution affects the density of the image lines recorded on the film original plate, when processing a signal of a high-magnification image by the observation optical system, it affects the accuracy of the image edge identification function. As a result, the autofocus accuracy and the length measurement accuracy are degraded.

Therefore, in order to eliminate the heat generation of the light source and the unevenness of the illuminance distribution, it is possible to use the illumination device of the coordinate measuring device disclosed in, for example, Japanese Patent Laid-Open No. 61-155907. This illuminating device includes a light source provided outside the measurement table, a support arm fixedly arranged below the measurement table, an end portion of the support arm bent upward (hereinafter referred to as a light projecting unit), and a light source. And a plurality of lenses that guide the light from the light transmitting member to the light projecting unit, and the light projecting unit irradiates only the observation region of the measured object. ing.

However, the illumination device for coordinate measurement and measurement is fixedly arranged in a state in which the light projecting unit matches the optical axis of the measuring unit,
Since only the measurement table is configured to move horizontally in the X-Y directions, there is a problem that the device becomes large.

The present invention has been made in consideration of such circumstances. Eliminate the adverse effects of the film original plate curling or expanding and contracting due to the heat generated by the light source, b. Eliminate the adverse effects of uneven illuminance distribution, c. Eliminating the lack of light, d. Moreover, it is a technical subject that, when it is carried out, it can be carried out relatively inexpensively without enlarging the length measuring device.

<< Means for Solving the Problems >> The present invention is configured as follows to solve the above problems.

That is, a measurement table on which an object to be measured is placed, a transillumination device that illuminates the object to be measured on the measuring table from below, and a position relative to the measurement table that can be moved in the XY directions and can be read. And an observation optical system for observing the object to be measured from above, and is configured to measure the object to be measured based on a relative movement amount between the object to be measured and the observation optical system in the XY directions. In the table type length measuring device described above, the transillumination device is provided with a light source outside the measurement table, and the light from the light source is provided below the measurement table via a light guide supported by a swing arm capable of horizontally swinging. Further, it is configured so that it is guided to a light projecting section provided at one end of the swing arm, and the light projecting section illuminates the observation area of the object to be measured, and the light projecting section and the observation optical system are provided. It is constructed so that it can move crosswise with respect to the moving direction of the measuring table. In addition, the light projecting unit and the observation optical system are interlockingly connected to each other via the rope of the rope-type winding interlocking means, and the observation optical system and the light projecting unit are configured to be synchronously translated. It is what

<< Operation >> In the present invention, the light source is provided outside the measurement table, and the light from the light source is provided at one end of the swing arm through the light guide supported by the swing arm capable of horizontal swing. Is guided to the projecting unit. As a result, the heat generation of the light source is substantially blocked by the light guide, and the object to be measured on the measurement table that is irradiated with light is not affected by heat.
Since the observation area of the object to be measured is illuminated with light that does not have a thermal effect, a sufficiently bright light source can be used if necessary.

In addition, since the light projecting section and the observation optical system are interlockingly connected to each other via the rope of the rope-type winding interlocking means, the observation optical system and the light projecting section are configured so as to be synchronously translated. The apparatus observes the state in which the observation region of the object to be measured is illuminated with a constant illuminance.

The measurement table moves only in one of the XY directions. On the other hand, the projection unit and the observation optical system, which are linked to each other, move in a direction intersecting with the moving direction of the measurement table, so that the entire apparatus is compared with the one in which the measurement table moves in the XY directions. Can be downsized.

Further, the light from the light source is guided to a light projecting unit provided under the measurement table via a light guide supported by a swing arm capable of horizontally swinging, so that interference between the light projecting unit and the measurement table is prevented. It is possible to bring the light projecting unit close to the lower side of the measurement table while avoiding it.

«Examples» Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of the rope-type winding interlocking means as seen from the rear of the measurement table (opposite operation side), and FIG. 2 is a perspective view of the winding drive means of the measurement table and the gantry as seen from the front (operation side) of the measurement table. FIG. 3 is a perspective view of a table type length measuring device comprising the interlocking means of FIG. 1 and the driving means of FIG.

The configuration of this table type length measuring device will be described below.

As shown in FIGS. 1 to 3, this table type length measuring device is provided so as to be movable in the front-rear (Y) direction, and the object to be measured W is measured.
A measurement table 4 on which is mounted, a transillumination device 30 for illuminating the object to be measured W on the measurement table 4 from below, and a movable left and right (X) direction with respect to the measurement table 4.
The observation optical system 20 for observing the object to be measured W from above and a monitor television 50 for displaying an enlarged image by the observation optical system 20 are provided, and the object to be measured W and the observation optical system 20 are XY relative to each other. By measuring the amount of movement with a linear encoder or the like (not shown), the object to be measured W is measured.

The measurement table 4 is provided so as to be movable in the front-back (Y) direction on the Y-direction guide rail 2 on the base 1, and as shown in FIG. It

Then, the winding drive means 10A, the drive motor 11,
Speed reducer 13 operated by the drive motor 11 or the operating handle 12a
And a drive pulley 13a of the speed reducer 13 and a plurality of idle pulleys 14 ...
A part of the wire 15 is wound around and a part of the wire 15 is attached to one side of the measuring table 4, and the driving motor 11 or the operating handle 12a controls the positioning of the measuring table 4 in the front-back (Y) direction. Is configured.

The observation optical system 20 is mounted on a pedestal 18 movably provided on the X-direction guide frame 17, and the X-direction guide frame 17 is fixed to the base 1 so as to straddle the measurement table 4. As shown in FIG. 2, the gantry 18 is driven by another wrapping drive means 10B so that its positioning can be controlled.

The winding driving means 10B has the point that the pedestal 18 is positioned in the left-right (X) direction by the wire 15b.
Unlike A, the configuration is similar in other respects, and thus redundant description will be omitted. The operation handles 12a and 12b
Instead of, the joystick on the control panel 26 in Fig. 3
The observation optical system 20 and the measurement table 4 can also be moved relative to each other in the X-Y directions by using 27.

As shown in FIG. 3, the observing optical system 20 includes a reflection illuminating device 22 in addition to a transmissive illuminating device which will be described later, so that a circuit pattern or the like formed on the surface of a printed wiring board or the like can be observed by the reflection illuminating. It is like this. In the figure, reference numeral 23 is a reflected light source, 24 is a photographing part of a television camera, and 25 is an operation handle for focusing.

The characteristic configuration of the present invention will be described below.

The transillumination device 30, as shown in FIG.
The light source 31 is provided on the rear side of the base 1 located outside the
The light 31 is guided into the measurement table 4 via the light guide 32, and the projection area 33 on the terminal end side of the light guide irradiates the observation region of the object W to be measured.

The light guide 32 is composed of a bundle of optical fibers, and is horizontally swingably supported through a pair of swing arms 35.

Then, the light projecting section 33 is provided with a reflecting mirror inside, and reflects light emitted from the front end surface of the light guide 32 upward,
It is configured to illuminate the object to be measured W from below through the light projecting plate 5 of the measurement table 4. It should be noted that the light projecting section 33 may be configured with the tip of the light guide 32 facing upward without using a reflecting mirror.

The light projecting portion 33 is connected to the tip end of the swing arm 35 with the point P as a swing fulcrum by a pin 36, and is provided so as to be movable along the X-direction guide rod 38. And the gantry 18 of the observation optical system 20 are the rope body 42a of the rope-type winding interlocking means 40.
The observation optical system 20 and the light projecting unit 33 are configured to be interlocked and coupled to each other via 42b in a synchronized manner.

As shown in FIG. 1, the rope-type winding interlocking means 40 is a pedestal.
Lock pin 19 on the right side facing the paper standing on the back of 18
One of the ropes 42a whose starting end is a and which terminates in the left side portion of the light projecting portion 33, and a plurality of idle rollers 43 around which the ropes 42a are wound.
a to 49a, the other rope body 42b forming a pair with the rope body 42a, and a plurality of idle rollers 43b to 49b.

These cords 42a and 42b intersect on the back side of the X-direction guide frame 17 via idler rollers 43a and 44a and 43b and 44b arranged on both ends fixed support members 16 and 16 of the X-direction guide frame 17, Idler rollers 45 arranged on both left and right sides of the base 1.
Light is diverted to the rear via a to 47a and 45b to 47b, and is emitted via idler rollers 48a, 49a and 48b, 49b arranged in the vicinity of both-end shaft support portions (not shown) of the X-direction guide rod 35. It is wrapped so that it goes to part 33. Wires, ropes, chains, belts and the like are used as the ropes 42a and 42b.

As a result, when the gantry 18 is moved in the X direction, the observation optical system 20 and the light projecting unit 33 are synchronously interlocked in the same direction with their optical axes aligned, and the measurement table 4 is moved in the Y direction. Cable 42a / 42b or idle roller 48a
.About.49b are configured so as not to interfere with the measurement table 4.

On the other hand, the rear end surface of the measurement table 4 is open, and slit-shaped elongated holes 6 are formed in the front-rear (Y) direction on both left and right sides of the lower surface, and the shaft support portion of the X-direction guide rod 38, It is configured to avoid interference with the idle rollers 48a-49b and the like. As shown in FIG. 1, the EL plate 8 may be arranged on the bottom surface of the measurement table 4 and used for visually observing the entire object to be measured.

<< Effects of the Invention >> As is apparent from the above description, the present invention has the following effects.

I. The light source of the lighting device is provided outside the measurement table,
Since the observation region of the object to be measured is illuminated by the light projecting portion via the light guide, it is possible to prevent the object to be measured from expanding and contracting or curling due to heat generation of the light source.

B. Since the observation optical system and the light projecting section are synchronized and linked in parallel, and the observation region of the object to be measured is always illuminated with a constant illuminance, it is possible to prevent the adverse effects caused by the uneven illuminance distribution as in the conventional example.

C. Since it is not necessary to consider the influence of heat generation of the light source, and a sufficiently bright light source can be used as necessary, it is possible to solve the shortage of light amount as in the conventional example.

D. The light projecting section and the observation optical system are configured to be capable of intersecting with the moving direction of the measurement table, and the light projecting section and the observation optical system are interlockingly connected to each other via the rope of the rope-type winding interlocking means. However, since the observation optical system and the light projecting unit are configured so as to be synchronized and translated, the entire length measuring apparatus can be downsized as compared with the case where the measurement table moves in the XY directions.

E. Further, since the light from the light source is guided to the light projecting section provided on the lower side of the measurement table through the light guide supported by the swing arm capable of horizontally swinging, the light projecting section and the measurement table are separated from each other. It is possible to dispose the light projecting unit close to the lower side of the measurement table while avoiding interference. As a result, it is possible to use a light source with less light quantity loss, smaller output, and less heat dissipation.

[Brief description of drawings]

FIG. 1 is a perspective view of the rope-type winding interlocking means as seen from the rear of the measurement table (opposite operation side), and FIG. 2 is a perspective view of the winding drive means of the measurement table and the gantry as seen from the front (operation side) of the measurement table. 3 is a perspective view of a table type length measuring device comprising the interlocking means of FIG. 1 and the driving means of FIG.
FIG. 4 is a side view of a main part of a conventional example, and FIG. 5 is a perspective view showing a conventional example of a table type length measuring device. W ... DUT, 4 ... Measurement table, 20 ... Observation optical system, 30 ... Transmitted illumination device, 31 ... Light source, 32 ... Light guide, 33 ... Projector, 35 ... Oscillation Arms, 40 ...... Cable-type wrapping interlocking means, 42a / 42b.

Claims (1)

[Claims] 1. A measurement table on which an object to be measured is placed, a transillumination device for illuminating the object to be measured on the measuring table from below, and a movable relative to the measuring table in the XY directions, and It is equipped with an observation optical system that can read the position and observes the measured object from above, and measures the measured object based on the relative movement amount of the measured object and the observation optical system in the XY directions. In the table-type length measuring device configured as described above, the transillumination device is provided with a light source outside the measurement table, and the light of the light source is measured via a light guide supported by a swing arm capable of horizontally swinging. It is configured to guide light to the light projecting section provided on the lower side of the swing arm and to one end of the swing arm, and to illuminate the observation region of the measured object with the light projecting section. Cross the optical system with the moving direction of the measuring table. In addition to the above configuration, the light projecting section and the observation optical system are interlockingly connected to each other through the rope of the rope-type winding interlocking means, and the observation optical system and the light projecting section are configured to be synchronously translated. A table type length measuring device characterized in that