JP2009085971A - Sensor head of optical displacement sensor - Google Patents

Abstract

An optical system capable of accurately measuring a gap between a nozzle tip and a glass plate while using a linear nozzle as a dispenser nozzle when applied to an adhesive application process using a dispenser. To provide a sensor head of a displacement sensor.
SOLUTION: A light emitting side block that houses a light emitting section and a light projecting optical system and that has a light projecting window, a light receiving optical system and a light receiving element are housed, and a light receiving window is opened. A light-receiving side block, and a coupling member that integrally couples the light-projecting side block and the light-receiving side block, and is located between the light-projecting side block and the light-receiving side block. A space that communicates in the vertical direction is provided at a position that is almost directly above, and by placing the linear nozzle of the dispenser vertically through this space, the nozzle is placed at the planned injection position. The gap between the tip of the nozzle and the surface of the measurement object almost directly below it can be measured while it is left.
[Selection] Figure 1

Description

  The present invention relates to a sensor head of an optical displacement sensor, and more particularly to a sensor head of an optical displacement sensor suitable for adhesive application work using a dispenser nozzle in an FPD (Flat Panel Display) production line.

  In adhesive application work using a dispenser in an FPD (Flat Panel Display) production line, gap management on the order of microns is required. An explanatory diagram of the adhesive application work using such a dispenser is shown in FIG.

  In the figure, a is a stage for conveying a glass plate, b is a glass plate, c is an adhesive, d is a relative movement direction of the dispenser, e is a dispenser head, f is a dispenser nozzle, and h is an elevation of the dispenser. The moving direction, G, is the gap between the tip of the dispenser nozzle and the glass plate.

  As is apparent from the figure, the glass plate b is conveyed by the stage a and passes under the nozzle f of the dispenser from the right to the left in the figure. Thereby, the nozzle f moves relatively to d direction with respect to the glass plate b. At this time, the adhesive agent is applied to the surface of the glass plate b by injecting the adhesive agent c from the tip of the nozzle f.

  The thickness of the adhesive c applied on the glass plate b depends on the size of the gap between the tip of the nozzle f and the surface of the glass plate b. If the size of the gap G between the tip of the dispenser nozzle f and the surface of the glass plate b to be coated varies during the conveyance of the glass plate b to be bonded, the thickness of the applied adhesive c is not uniform. As a result, the product yield decreases.

  Therefore, an optical displacement sensor has been conventionally used for managing the gap between the tip of the dispenser nozzle and the coating target glass plate in this type of FPD production line. That is, the height of the tip of the dispenser nozzle f is servo-controlled via a predetermined lift drive mechanism so that the gap value measured by the optical displacement sensor is always a specified value.

  As the optical displacement sensor, an amplifier separation type displacement sensor in which a sensor head and a signal processing unit (commonly referred to as an amplifier unit) are separated is employed. As the sensor head of the amplifier separation type displacement sensor, the diffuse reflection type and the regular reflection type are known, but the specular reflection type sensor head is used for specular objects such as glass. Is done.

  The basic structure of the specular reflection-compatible sensor head consists of a light emitting unit that serves as a light source, a light projecting optical system that irradiates light from the light emitting unit along a light projecting optical axis that is inclined with respect to the measurement object, and a measurement A light receiving optical system that captures reflected light from an object along a light receiving optical axis that is symmetrically tilted in a direction opposite to the tilting direction of the light projecting optical axis, and a reflection that is captured through the light receiving optical system. A light receiving element that receives light and performs photoelectric conversion is housed in a case having a predetermined shape (see Patent Document 1).

  FIG. 9 is an explanatory diagram showing the arrangement relationship between the conventional dispenser and the sensor head. In the figure, b is a glass plate, e is a dispenser head, f is a dispenser nozzle, j is a sensor head, L1 is a light projecting optical axis, and L2 is a light receiving optical axis.

  As an example of the arrangement of the nozzle f and the sensor head j of the dispenser, the first conventional example shown in FIGS. (A1) and (b1) and the second conventional example shown in FIGS. (A2) and (b2) Exists. In the first conventional example, the nozzle f itself is a straight one, and the measurement points (L1, L2) of the sensor head j are arranged on the side of the nozzle f and adjacent thereto. In the second conventional example, the nozzle f is bent in a crank shape, and the measurement points (L1, L2) of the sensor head j are arranged at substantially the same position as the tip of the nozzle f.

International Publication WO 01/73375 A1 Brochure

  However, in the above-described first conventional example, if the glass plate b is bent or wavy because the tip of the nozzle f and the measurement point of the sensor head j are too far apart, There is a problem that the gap value measured by j is different from the gap value between the nozzle tip and the glass plate (actual gap value).

  On the other hand, in the above-described second conventional example, since the tip of the nozzle f and the measurement point of the sensor head j are close to each other, even if the glass plate b is bent or waved, the sensor head j The gap value measured in (1) and the gap value between the nozzle tip and the glass plate (actual gap value) are not very different. However, in addition to the time and effort required to bend the nozzle f into a crank shape, when the nozzle f is bent, the flow of the adhesive flowing inside the nozzle f becomes unstable and the injection operation becomes unstable. There are problems.

  The present invention has been made paying attention to the above-mentioned problems, and its object is to use, for example, a linear nozzle as a dispenser nozzle when applied to an adhesive application process using a dispenser. However, it is an object of the present invention to provide a sensor head of an optical displacement sensor capable of accurately measuring a gap between a nozzle tip and a glass plate.

  Other objects and operational effects of the present invention should be easily understood by those skilled in the art by referring to the following description of the specification.

  The sensor head of the optical displacement sensor of the present invention includes a light emitting unit that serves as a light source, a light projecting optical system that irradiates light from the light emitting unit along a light projecting optical axis that is inclined with respect to the measurement object, A light receiving optical system that captures reflected light from a measurement object along a light receiving optical axis that is symmetrically tilted in a direction opposite to the tilting direction of the light projecting optical axis, and the light received through the light receiving optical system. A light receiving element that receives reflected light and performs photoelectric conversion is housed in a case having a predetermined shape.

  The case of the predetermined shape contains the light emitting part and the light projecting optical system, and the light projecting side block where the light projecting window is opened, the light receiving optical system and the light receiving element, and the light receiving window is opened. A light receiving side block, and a coupling member that integrally couples the light projecting side block and the light receiving side block. A space that communicates in the vertical direction is provided at a position that is substantially above the irradiation point.

  Thereby, the gap between the tip of the nozzle and the surface of the measurement object almost directly below it can be measured by disposing the linear nozzle of the dispenser vertically in this space.

  According to such a configuration, since the measurement point by the sensor head is located almost directly below the tip of the dispenser nozzle, when applied to an adhesive application process using a dispenser, a linear nozzle is used as the dispenser nozzle. While being used, the gap between the nozzle tip and the glass plate can be accurately measured.

  In a preferred embodiment, the light projecting side block surrounds a light projecting side substrate on which components constituting the light emitting unit and the light projecting optical system are mounted, and a component mounted on the light projecting side substrate, and It is assumed that it consists of a floodlight side cover in which a floodlight window is opened. Similarly, the light receiving block includes a light receiving side substrate on which components constituting a light receiving optical system and a light receiving element are mounted, and a light receiving side that surrounds the components mounted on the light receiving side substrate and has a light receiving window. It shall consist of a cover. Further, the light-projecting side substrate, the connecting member, and the light-receiving side substrate are shared by a single flat support plate.

  According to such a configuration, the parts constituting the light emitting unit and the light projecting optical system, and the parts constituting the light receiving optical system and the light receiving element are all mounted on one flat support plate. Therefore, the positioning accuracy of the optical system is improved, and the structure is simple and robust.

  In a preferred embodiment, a cutout portion that functions as a window facing the light irradiation point on the object to be measured may be formed at a position adjacent to the void of the support plate. According to such a configuration, the notch portion functions as a window facing the light irradiation point on the object to be measured, so that the relationship between the tip of the nozzle and the measurement point can be visually confirmed or illuminated. Is possible.

  In a preferred embodiment, the support plate may be provided with an attachment for attaching to the dispenser. Thereby, a sensor head can be firmly fixed to a dispenser.

  In a preferred embodiment, the opening surface of the light projection window and the opening surface of the light receiving window may be inclined surfaces that are symmetrically inclined with respect to each other. According to such a configuration, even when the distance between the nozzle and the glass plate is close, the value of the gap can be accurately measured.

  According to the present invention, since the measurement point by the sensor head is located almost directly below the tip of the dispenser nozzle, a linear dispenser nozzle is used when applied to an adhesive application process using a dispenser. However, the gap between the nozzle tip and the glass plate can be accurately measured.

It is the external appearance perspective view seen from the left diagonal front of this invention sensor head. It is the external appearance perspective view seen from the diagonally right front of this invention sensor head. It is the external appearance perspective view seen from the lower diagonal front of this invention sensor head. It is an external appearance projection view of the sensor head of the present invention. It is a perspective view which shows the internal structure of this invention sensor head. It is a figure which shows the relationship between the optical component arrangement | positioning of this invention sensor head, and an optical path. It is a figure which shows the state which mounted | wore the dispenser with this invention sensor head. It is explanatory drawing of the adhesive agent application operation | work which uses a dispenser. It is a perspective view which shows the relationship between the conventional dispenser and a sensor head.

  In the following, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is an external perspective view of the sensor head of the present invention as viewed from the left diagonal front, FIG. 2 is an external perspective view of the sensor head as viewed diagonally forward from the right, and FIG. Projections are shown in FIG.

  The sensor head of the present invention includes a light emitting unit (details will be described later) serving as a light source, and a light projecting optical system that irradiates light from the light emitting unit along a light projecting optical axis inclined with respect to a measurement object (details). A light receiving optical system (details will be described later) for capturing reflected light from a measurement object along a light receiving optical axis that is symmetrically tilted in a direction opposite to the tilting direction of the light projecting optical axis, A light-receiving element (details will be described later) that receives and photoelectrically converts reflected light taken in via the light-receiving optical system is housed in a case having a predetermined shape.

  As shown in FIGS. 1 to 4, in this example, the case having a predetermined shape is formed by integrating the light projecting side block 2, the light receiving side block 3, and the light projecting side block 2 and the light receiving side block 3. And a connecting member (details will be described later). A space 17 that communicates in the vertical direction is provided between the light projecting side block 2 and the light receiving side block 3 and at a position that is substantially directly above the light irradiation point on the measurement object.

  As will be described later, by disposing the linear nozzle 26 of the dispenser vertically in this space 17 (see FIG. 7 for details), the nozzle 26 is left at the expected injection position, It is possible to measure the gap with the surface of the measurement object almost directly below.

  More specifically, the light projecting side block 2 includes a light projecting side substrate (details will be described later) on which components constituting the light emitting unit and the light projecting optical system are mounted, and a component mounted on the light projecting side substrate. It is composed of a light projecting window 9 which surrounds and has a light projecting window 9 and a urn. Similarly, the light receiving block 3 surrounds a light receiving side substrate (details will be described later) on which the components constituting the light receiving optical system and the light receiving element are mounted, and the components mounted on the light receiving side substrate, and includes a light receiving window. 10 includes a light receiving side cover 5 opened. The light emitting side substrate, the connecting member, and the light receiving side substrate are shared by a single flat support plate.

  According to such a configuration, the parts constituting the light emitting unit and the light projecting optical system, and the parts constituting the light receiving optical system and the light receiving element are all mounted on the single flat support plate 6. Therefore, the positioning accuracy of the optical system is good, and the structure is simple and robust.

  That is, as shown in FIGS. 5 and 6, the support plate 6 has a region functioning as a light emitting side substrate (right side region in the figure) and a region functioning as a light receiving side substrate (left side region in the figure). In the region functioning as the light projecting side substrate, components (light emitting element substrate 18, light projecting lens 19, lens holder 20, etc.) constituting the light emitting section and the light projecting optical system are mounted, and the light projecting cover 4 Overlaid. In the region functioning as the light receiving side substrate, components (light receiving lens 21, reflecting mirror 23, light receiving element assembly 24, etc.) constituting the light receiving optical system and the light receiving element are mounted, and the light receiving cover 5 is covered thereon. It is done.

  On the support plate 6, a notch 11 is formed at the boundary between the light projecting substrate region and the light receiving substrate region. The notch 11 is formed at a position facing the measurement point (light irradiation point) from obliquely above, and illumination light can be applied to the measurement point when the measurement point is monitored by a camera or the like. 1 to 5, 7 is an electric cord, 8 is a plug, and 12 to 15 are mounting holes.

  According to such a configuration, as shown in FIG. 7, the linear nozzle 26 of the dispenser is vertically penetrated and disposed in the empty space 17, so that the nozzle 26 remains in the expected injection position, and the nozzle Since the gap between the tip and the surface of the measurement object (glass plate 27) almost directly below it can be measured, the measurement point by the sensor head is located almost directly below the tip of the dispenser nozzle 26, so a dispenser is used. When applied to the adhesive application process, it is possible to accurately measure the gap between the nozzle tip and the glass plate 27 while using a linear dispenser nozzle 26.

  Particularly in this example, since the light projection window forming surface 4a and the light receiving window forming surface 5a are symmetrically inclined, even when the nozzle 26 and the glass plate 27 are close to each other, Since it is wide, there is also an advantage that the target gap G can be measured with high accuracy.

  In the above embodiment, a laser diode (LD), a light emitting diode (LED), or the like can be used as the light emitting element. As the light receiving element, a one-dimensional or two-dimensional CMOS image sensor, a one-dimensional or two-dimensional CCD, PSD, or the like can be used. Further, the cross-sectional shape of the projection may be a dot or a line.

  In addition, the sensor head 1 of the present invention can be set at a measurement point exactly below the nozzle 26 due to its nature. However, in the actual adhesive application operation, the sensor head 1 is slightly laterally below the nozzle 26. It is preferable to use the position shifted as a measurement point. By doing so, erroneous measurement of the gap due to the injected adhesive can be avoided.

  According to the present invention, since the measurement point by the sensor head is located almost directly below the tip of the dispenser nozzle, when applied to an adhesive application process using a dispenser, a linear nozzle is used as the dispenser nozzle. However, the gap between the nozzle tip and the glass plate can be accurately measured.

DESCRIPTION OF SYMBOLS 1 Sensor head 2 Light emission side block 3 Light reception side block 4 Light emission side cover 4a surface 5 Light reception side cover 5a surface 6 Support plate 7 Electric cord 8 Plug 9 Light projection window 10 Light reception window 11 Notch 12 Installation hole 13 Installation hole 14 Installation Hole 15 Mounting hole 17 Space 18 Light emitting element substrate 19 Light projecting lens 20 Lens holder 21 Light receiving lens 22 Lens holder 23 Reflector 24 Light receiving element assembly 25 Dispenser head 26 Dispenser nozzle 27 Glass plate L1 Light projecting optical axis L2 Light receiving Optical axis a Stage b Glass plate c Adhesive d Nozzle relative movement direction e Dispenser head f Dispenser nozzle h Nozzle up / down direction j Sensor head G Gap

Claims (5)

A light emitting unit that is a light source, a light projecting optical system that irradiates light from the light emitting unit along a light projecting optical axis inclined with respect to the measurement target, and a light projecting optical axis that reflects light from the measurement target A light-receiving optical system that captures along a light-receiving optical axis that is symmetrically tilted in a direction opposite to the tilt direction, and a light-receiving element that receives and photoelectrically converts reflected light captured via the light-receiving optical system, and In a case with a predetermined shape,
The case of the predetermined shape is
A light projecting side block that houses a light emitting unit and a light projecting optical system and has a light projecting window,
A light receiving side block that houses a light receiving optical system and a light receiving element and has a light receiving window;
It has a coupling member that integrally couples the light projecting side block and the light receiving side block, and is located between the light projecting side block and the light receiving side block, and is almost right above the light irradiation point on the measurement object. There is a space in the vertical position that communicates vertically.
Thereby, the gap between the tip of the nozzle and the surface of the measurement object almost directly below it can be measured by arranging the linear nozzle of the dispenser vertically in this space. Sensor head for optical displacement sensor. Emitter block
From a light emitting side substrate on which components constituting the light emitting part and the light projecting optical system are mounted, and a light emitting side cover that surrounds the components mounted on the light emitting side substrate and has a light projection window opened Become
The light receiving block
A light receiving side substrate on which the components constituting the light receiving optical system and the light receiving element are mounted, and a light receiving side cover surrounding the component mounted on the light receiving side substrate and having a light receiving window opened. 2. The sensor head of the optical displacement sensor according to claim 1, wherein the side substrate, the connecting member, and the light receiving side substrate are shared by a single flat support plate.   The optical displacement sensor according to claim 2, wherein a notch portion functioning as a window facing a light irradiation point on the object to be measured is formed at a position adjacent to the void of the support plate. Sensor head.   The sensor head of the optical displacement sensor according to claim 2, wherein the support plate is provided with an attachment for attaching to the dispenser.   3. The sensor head of the optical displacement sensor according to claim 2, wherein the opening surface of the light projection window and the opening surface of the light receiving window are inclined surfaces that are symmetrically inclined with respect to each other.

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