JPS63304763A - Graphic reader - Google Patents

Abstract

PURPOSE:To improve operability and to reduce the burden of an operator by providing in a second focusing part a glass member and an intervening structure which sets the glass member to freely intervene in an optical axis between an image pickup means and a read graphic surface. CONSTITUTION:The second focusing part is provided with the glass member 36 and the intervening structure 37 which sets the glass member 36 to freely intervene in the optical axis between the image pickup means 18 and the read graphic surfaces 5A and 5B. Namely, a distance between the image pickup means 18 and the read graphic surface 5A (5B) can continuously be adjusted in a prescribed range by a first focusing part 21. If the glass member 36 in the second focusing part 16 is set to intervene in the optical axis between the image pickup means 18 and the read graphic part 5A (5B) in a state that a focus position by the first focusing part 21 is set constant, the focus distance of the image pickup means 18 is prolonged. With adequately setting the optical axis incident angle, and the thickness and the refractive index of the glass member 36 and the like, the focus can adaquately be adjusted on a pattern film surface and a printing substrate surface only by an easy operation whether to set the glass member 36 to intervene in the optical axis or not.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a figure reading device, and in particular, it is possible to use an image capturing means such as a scanner camera without moving the image capturing means up and down in a direction facing the reading figure surface. The present invention relates to a figure reading device which is provided with a mechanism that can apparently adjust the focal distance with respect to the reading figure surface in a stepwise manner.

[Conventional technology]

Conventional figure reading devices include, for example, an X-Y table having an X-Y coordinate axis plane, and a printed circuit board pattern film (object) placed on this X-Y table.
a light source that illuminates the film surface (reading figure surface); an imaging means such as a scanner camera arranged one-dimensionally or two-dimensionally that receives the transmitted light or reflected light of the illumination light by the film surface; It is equipped with a drive means for moving the table or the imaging means one-dimensionally or two-dimensionally, and a control means for controlling the entire apparatus, and coordinates the center position of the land on the film surface on the X-Y coordinate plane. A configuration is known in which data is output as drilling data to a printed circuit board drilling m (driller). In other words, while automatically scanning the film surface, large defects, dust, pinholes, etc. are removed and only the lands to be read are selected. This is to determine the quality of the so-called land hole diameter and to read the center coordinates of the appropriate land through arithmetic processing and convert them into coordinates.

In order to improve the resolution, this type of apparatus is generally equipped with a focus adjustment means for adjusting the position of the reading pattern surface on the film surface in the optical axis direction to match the focal position of the lens of the imaging means. This focus adjustment means is configured to be able to continuously move either the X-Y table or the imaging means within a predetermined range in the optical axis direction, and conventional examples thereof include, for example, one using an electromagnetic drive mechanism. (For example, JP-A No. 62-109238.' No. 62-109239.

(see No. 62-112238), rack-and-binion drive mechanisms, ball screw nut mechanisms,
A drive mechanism using an electrostrictive element, a drive mechanism that moves an X-Y table in the Z-axis direction (for example, 62
-86319) etc. are known.

[Problem that the invention seeks to solve]

By the way, the above-mentioned pattern reading device can detect, for example, a printed circuit board (with a standard thickness of 1°) in addition to determining the diameter of a land hole in a pattern film (generally 0.1 to 0.2 mm thick) or reading the center coordinates of a land. 6mm) hole position confirmation and hole diameter measurement are frequently performed. In such a case, in conventional devices, the operator operates the focus adjustment means described above to adjust the focal length each time the pattern film reading operation is switched to the printed circuit board reading operation or vice versa. Since it was necessary to make minute adjustments, a lot of time and effort was spent on this adjustment work, which significantly reduced work efficiency.
There is a problem in that a great deal of skill is required if this adjustment work is to be carried out quickly.

Therefore, the present invention was made by focusing on the problems of the conventional techniques, and in particular, it is possible to perform continuous focus adjustment as in the conventional technique, and it is also possible to make a combination of a printed circuit board and a patterned film. Even for operations that require stepwise adjustment of the optical axis optical path difference, that is, the focal length, the adjustment operation can be performed more quickly and accurately by hour wheel operation. The object of the present invention is to provide a graphic reading device that can diversify work, improve operability, and reduce the burden on the operator.

[Means for solving problems]

In order to achieve the above object, the present invention includes at least a table on which an object having a reading pattern surface is placed, a light source for illuminating the reading pattern surface, and a light source that transmits light from the reading pattern surface. or comprising an imaging means for receiving reflected light, a driving means for moving the table or the imaging means one-dimensionally or two-dimensionally, and a focus adjustment means for adjusting the focal position of the imaging means with respect to the reading figure surface. In the figure reading device, the focus adjustment means includes a first focus adjustment section that continuously adjusts the distance between the image pickup means and the reading figure surface, and a focal length of the image pickup means that appears to be gradually adjusted. and a second focus adjustment section that adjusts to a glass member, and the second focus adjustment section that allows the glass member to be present or absent in the optical axis between the image pickup means and the reading pattern surface. The invention is characterized in that it includes an intervening mechanism for intervening.

[Effect]

In this invention, the distance between the image pickup means and the reading pattern surface can be continuously adjusted within a predetermined range by the first focus adjustment section, thereby making it possible to perform focusing. On the other hand, when the glass member of the second focus adjustment section is interposed in the optical axis between the imaging means and the reading pattern surface while the focus position by the first focus adjustment section is kept constant, the glass member Since the refractive index of the glass member is larger than that of air, the focal length of the imaging means becomes longer than when no glass member is used. For this reason, for example, as a reading figure surface, the thickness Q,
One related to a 1mm pattern film and one with a thickness of 1.
When using 5mm printed circuit boards alternately, if the angle of incidence of the optical axis on the glass member, the thickness and refractive index of the glass member, etc. are set appropriately, it is possible to insert the glass member in the optical axis. The pattern film surface and the printed circuit board surface can be accurately focused by a simple operation of turning on or off.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

1 to 7 are diagrams showing a first embodiment of the present invention.

First, FIG. 7 shows the external appearance of the graphic reading device according to the present invention. In the same figure, 2 is the main body of the device, 4 is a table with a pattern film 5A or a printed circuit board 5B as an object provided on the top of the main body 2 of the device, and the mounting surface is a mirror surface made of chrome plating. Reference numeral 6 designates reading detection units provided with their optical axes facing the table 4. 8 is a console for inputting data and the like.

As shown in FIG. 1, the reading detection section 6 includes a camera body 10 that is generally box-shaped as a whole, and a camera body 1.
0 and a light source 12 fixed to one side of the camera body 1
0, and a second focus adjustment unit 16 that is provided at the bottom of the camera body IO and can adjust the focal length of a scanner camera 18, which will be described later, in stages. It is configured as follows.

Among these, the camera body 10 accommodates a scanner camera 1B (see FIG. 4) as an imaging means, while the other side of the camera body 10 is connected to a camera moving table 20. Between the camera body 10 and the camera movement table 20, there is a rack and pinion mechanism 21 as a first focus adjustment section in order to continuously adjust the position of the scanner camera 18 in the Z-axis direction within a predetermined range. It is mediated.

A rack 22 in this rank and pinion mechanism is fixedly installed on the camera body 10 side, a pinion 24 is fixedly installed on the camera axis table 20 side, and a knob 2 connected to the pinion 24 is fixedly installed on the camera body 10 side.
By turning 4A, the entire reading detection section 6 can be connected to the scanner camera 18 and pattern film 5A or printed circuit board 5.
It is movable in the Z-axis direction in order to adjust the distance from the reading figure surface of B. .

Further, a lens barrel 26 of the scanner camera 18 extends from the center position of the bottom of the camera body 10 toward the table 4.

Here, the second focus adjustment section 16 and the rack and pinion mechanism 21 form a focus adjustment means.

As shown in FIG. 2-3, the second focus adjustment section 16 is suspended by a support member 28 fixed to the bottom of the camera body 10 near the light source 12. A shaft 30, a glass holding plate 34 rotatably supported in the X-Y plane by a pivot 32 at the lower end of the shaft 30, and a plate mounted on the glass holding plate 34 at a position close to and facing the lens barrel 26. Optical glass 36 as a glass member formed in a rectangular shape (for example, crown glass)
It is composed of. Here, the support member 28, the shaft 3
0. The pivot 32 and the glass holding plate 34 constitute an intervening mechanism 37.

Therefore, when the optical glass 36 is interposed below the lens barrel 26 (see the solid line in FIG. 3), the light incident from the lens barrel 26 is transmitted through the optical glass 36 and the second
(See the solid line in FIG. 3) From this state, by rotating the glass holding plate 34 and removing the optical lath 36 from the position facing the lens barrel 26 (see the two-dot chain line in FIG. 3), the optical axis can be directly The table 4 is reached (see the two-dot chain line in FIG. 2).

On the other hand, the driving portion of the camera axis table 20 is engaged with a pawl screw 42 directly connected to a step motor 40, and the camera moving table 20 is rotated by the rotation of the step motor 40. That is, the entire reading detection section 6 is movable in the Y-axis direction perpendicular to the longitudinal direction (X-axis direction) of the main body 2 of the apparatus. Further, the driving portion of the table 4 is meshed with a ball screw 46 directly connected to a step motor 44, and the table 4 is rotated by rotation of the step motor 44.
is movable in the X-axis direction. The step motors 40 and 44 are driven by a controller 60, which will be described later, to perform positioning on the XY plane.

Furthermore, the scanner camera 18, as shown in FIG.
A lens 50 that condenses light from the light source 12, a first half mirror 52 that irradiates the incident light through this lens 50 onto an object and transmits the reflected light, and this first half mirror 52. an objective imaging lens 54 (held by a lens barrel 26) placed between the object and the object; a second half mirror 56 located behind the optical axis of the first half mirror 52; It is configured to include a one-dimensional image sensor 58 that receives reflected light via a half mirror 56. Among these, a monitor signal for the monitor 14 is obtained from the second half mirror 56.

Then, the detection signal (2
A value signal) is input to a controller 60 comprising a microcomputer, and the controller 60 reads the land diameter of the pattern film 5A or calculates the hole diameter based on the detection signal. Further, this controller 60 controls the step motor 40.
．． 44 through drive circuits 62A and 62B, and is set in advance so that the table 4 and reading detection section 6 can be relatively moved two-dimensionally on the XY plane for automatic scanning.

Here, in the above configuration, the relationship between the incident angle I of the optical axis with respect to the optical glass 36 and the plate thickness T of the optical glass 36 will be explained with reference to FIGS. 5 and 6.

As shown in FIG. 5, a case will be considered in which incident light incident on the optical glass 36 at an incident angle of {circle around (2)} is refracted at a refraction angle I', and this light is irradiated onto the table 4. In this case, the thickness of the optical glass 36 is T.

The refractive index of the air is nOr, and the refractive index of the optical glass 36 is n8.
The board thickness of the printed circuit board 5B as the object to be read placed on the table 4 is y, and
If the distance difference between the optical axes on the Y plane is l, no ・5inI=n, ・5inl'...
(1) T-tanl-T-tanI'=1 - (2
)1=y−t a n I −・
...The relationship (3) holds true. From formula 11, ■ '-5in-' ((no /n+)
・ sin I)... (4) is obtained, and equations (21 and 31) are obtained. Therefore, from equations (4) and +51, the relationship between plate thickness T and incident angle ■ is tan Ltan (sin-' ((no/n +)
・sin I) )... (6)

Therefore, as a specific numerical value, y=1. 6 (mm),
n (If 1 = l, nt = 1.5, the angle of incidence is the same)
Typical values for and plate thickness T (mm) are: When 1=0.1°, when T=4.800471-7°, T#4.7651! When =45°,
T#3.4376 was obtained, whose I=0.1'~45°
The curve shown in FIG. 6 is obtained by showing the entire process. In this curve,! =0.1” to 7° is the incident angle 1
This is an area where the plate thickness T changes little even if the
In this embodiment, the incident angle I and the plate thickness T are set using this area.

In other words, in this example, the objects are a pattern film 5A (thickness Q, 1 mm) and a printed circuit board 5B (thickness 1 mm).
．． 6 mm) and □ as needed, the thickness T of the optical glass 36 is 4° 8 mm, and the incident angle is □.
was set at 5°.

Next, the operation of the above embodiment will be explained.

First, a case will be described in which a pattern film 5A is set as an object to be read. In this case, the glass holding plate 34 of the second focus adjustment section 16 is rotated to interpose the optical glass 36 in the optical axis (see the solid line in FIG. 3), and in this state, the rack and pinion mechanism 21 is rotated. Turn the knob 24A to finely adjust the focus so that it matches the film surface of the pattern film 5A. Then, when a command is given to the controller 60, the controller 60 drives the step motors 40, 44 via the motor drive circuits 62A, 62B based on a predetermined program.
Performs automatic scanning within a plane.

The incident light in this state is from the light source 12. Lens 50, first half mirror 52, lens 54, and optical lens 36
The pattern film 5A is reached through the following sequentially. At this time, since the incident light on the optical lens 36 has a refractive index different from that of air, it is refracted as shown by the solid line in FIG. 2, and the focal length of the upper lens 54 appears to be longer.

Then, the reflected light from the pattern filter 5A returns to the lens 54. The light reaches the image sensor 58 via the first half mirror 52 and the second half mirror 56, and the sensor 58 uses photoelectric conversion to output a detection signal according to the reading of the land etc. to the controller 60. In accordance with a predetermined program, the controller 60 detects the land diameter, converts the center position into coordinates through arithmetic processing, and automatically selects the hole diameter by color-coding the land in accordance with the drill diameter.

Next, a case will be described in which a printed circuit board 5B is set as an object to be read. In this case, the glass holding plate 34 is rotated to remove the optical glass 36 from the optical axis (see the two-dot m line in FIG. 3) and driven in the XY directions as in the case described above.

At this time, the optical axis between the scanner camera 18 and the printed circuit board 5B is a straight line without refraction, as shown by the solid line in FIG. It matches on the printed pattern surface of.

Then, an enlarged image of the printed circuit pattern is displayed on the monitor 14, so that it is possible to easily confirm the position of holes in the printed circuit board through visual inspection.

In this way, in this embodiment, the Z of the conventional scanner camera 18 is used as the focusing mechanism operated during figure reading.
In addition to a mechanism for continuously varying the axial distance, there is also a mechanism for varying the focal length of the scanner camera 18 in an apparently stepwise manner without moving the position of the scanner camera 18 itself in the Z-axis direction.

For this reason, for example, when it is necessary to alternately read the graphic surfaces of the pattern film 5A and the printed circuit board 5B, depending on whether or not the glass holding plate 34 is rotated to interpose the optical glass 36 in the optical axis. The focus can be adjusted, and there is no need to perform focus adjustment using the rank and pinion mechanism 21, which requires skill to operate, and the work can be done extremely easily and quickly.It improves the operability and improves the figure reading work. This method has the advantage of increasing throughput, reducing the operational burden on the operator, and eliminating the need for special skill.

Next, a second embodiment of the present invention will be described using FIG. 8.

Here, the same components as those in the first embodiment described above are given the same reference numerals, and the explanation thereof will be omitted or simplified.

The second focus adjustment section 76 in this second embodiment is the eighth
As shown in the figure, with respect to the shaft 30, the glass holding plate 78A,
Three pieces, 78B and 78C, are integrally installed to form an intervening mechanism 79 that is rotatable in the X-Y plane. The glass holding plates 78A, 78B, and 78C have optical glasses 80
A, 80B.

80C are installed in the same manner as in the first embodiment described above. The plate thicknesses of these optical glasses 80A to 80C are:
For example, if the thickness is increased in the order of 80A, 80B, and 80C, there is no optical glass with respect to the optical axis, optical glass 80A, optical glass 80B,
Assuming that the intervening mechanism 79 is rotated around 1 of 80C,
The focal point of the optical axis is set when the thickness of the printed circuit board 5B is large (for example, 4
mm), medium thickness (e.g. 3mm), small thickness (e.g. 1.6mm), and pattern film 5A (e.g. 0.1mm thick) using the same numerical values as described above to suit each graphic surface. Determined by settings.

The other configurations are the same as those of the first embodiment described above.

Therefore, according to the second embodiment, the effect is the same as that of the first embodiment.
In addition to obtaining something equivalent to the example, the distance to the reading symmetric figure surface can be changed in stages and in multiple types, for example, when using printed circuit boards 5B, . . . , 5B with different board thicknesses and pattern film 5A. Even if there is a change over time, this can be easily dealt with, and the operability can be improved in the same way as in the first embodiment.

Although optical glass is used as the glass member in each of the embodiments described above, it is sufficient that the optical glass has a different refractive index from that of air, and may be a mere temporary glass or a lens. Moreover, its shape is not limited to a plate shape, and may have a spherical surface, for example.

Furthermore, the number of glass members is not limited to one or three as described above, and may be any other number as necessary.

Furthermore, although the optical glass 36 has been described as having a rectangular shape, it may also have an area that can transmit the required amount of light reflected from the lens barrel 26 (for example, it may be circular).

Further, the glass holding plate 34 may have a circular shape and be rotatable about the shaft 30, and may have a structure in which a plurality of optical glasses 36 having different refractive indexes are disposed in the circular shape in the circumferential direction.

Furthermore, the glass holding plate 34 is rotated to an appropriate position to receive the light projected from the lens barrel 26.

For example, a notch is provided relative to the shaft 30 and the fitting sliding surface of the shaft 30 of the glass holding plate 34 so that the shaft 30 can be stopped.
A structure may be adopted in which a left leaf spring that fits into the notch is formed.

Furthermore, in each of the above-mentioned embodiments, a case has been described in which a rack-and-binion mechanism is installed as the first focus adjustment section. Of course, even if there is, the above-mentioned advantages can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the focus adjustment means in the figure reading device is composed of the first focus adjustment section that continuously adjusts the distance between the imaging means and the table as in the conventional case, and the imaging means. The focal length of the lens is adjusted in stages.
The focus adjustment unit includes a glass member and an intervening mechanism that allows the glass member to be freely inserted into the optical axis leading to the reading figure surface. When reading a pattern by attaching a thicker printed circuit board or the like from a film, it is possible to easily adjust the focal length by adjusting whether or not the glass member of the second focus adjustment section is interposed in the optical axis. As a result, the difference in focal length due to the size of the plate thickness can be adjusted in stages, making it possible to perform this work quickly and easily, improving the throughput of figure reading work. It is also possible to reduce the operational burden on the operator and reduce the effort required to learn the operation. Therefore, when used in conjunction with the first focus adjustment section, the focus adjustment method can be diversified, and an excellent figure reading device is provided in which focus adjustment can be easily performed according to various work situations. can do.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, and FIG.
The figure is an explanatory diagram of the optical axis in the first embodiment, Figure 3 is an explanatory diagram showing the presence or absence of the glass member on the optical axis in the first embodiment, and Figure 4 is an explanatory diagram showing the optical axis in the first embodiment. A block diagram showing an outline of the signal path, FIG. 5 is an explanatory diagram for calculating the plate thickness of the glass member in the first embodiment, and FIG. 6 shows the incident angle I of the optical axis and the optical glass plate in the first embodiment. FIG. 7 is a graph showing the relationship with the thickness T, FIG. 7 is an external view showing the outline of the device according to the present invention, and FIG. 8 is an explanatory view showing the mounting situation of the glass member in the second embodiment of the present invention. In the figure, 4 is a table, 5A is a pattern film as an object, 5B is a printed circuit board as an object, 10 is a camera body, 12 is a light source, 16.76 is a second focus adjustment section (focus adjustment means), 18 is a scanner camera as an imaging means, 21 is a rack and pinion mechanism (focus adjustment means) as a first focus adjustment section, 30 is a camera moving table as a driving means, and 36. 80A, 80B, 80C are glass members. optical glass, 37.79 is an intervening mechanism, 4
0.44 is a step motor as a driving means, 42.4
6 is a ball screw as a driving means, 60 is a controller as a driving means, and 62A. 62B is a drive circuit as a drive means.

Claims (3)

[Claims] (1) At least a table on which an object is placed having a reading figure surface, and a light source illuminating the reading figure surface;
an imaging means for receiving transmitted light or reflected light from the reading figure surface; a driving means for moving the table or the imaging means one-dimensionally or two-dimensionally; and adjusting a focal position of the imaging means with respect to the reading figure surface. A figure reading device comprising: a first focus adjustment section that continuously adjusts the distance between the imaging means and the reading figure surface; and a focal length adjustment section of the imaging means. It is formed by a second focus adjustment section that apparently adjusts in steps, and the second focus adjustment section includes a glass member and a light source between the image pickup means and the reading pattern surface. A figure reading device characterized by comprising an intervening mechanism that is freely interposed in the shaft. (2) The figure reading device according to claim 1, wherein the glass member is formed in a plate shape. (3) The glass member is composed of a plurality of glass members,
2. The figure reading device according to claim 1, wherein the intervening mechanism is configured to sequentially interpose a plurality of glass members in the optical axis as desired.