JPH01276090A - Light-transmissive object detector - Google Patents

Abstract

PURPOSE:To easily detect a light-transmissive object (LCD) by obliquely irradiating light to the object and detecting the object from a change in optical path produced by the refraction of the irradiating light inside the light-transmissive object. CONSTITUTION:The optical path 25 of the light made obliquely incident to the LCD 2 from a light emitting section 23a is deviated from the optical path 26 of the light emitted to the air from the LCD 2 in parallel with the optical path 25. The deviated quantity DELTAt of the optical path 26 from the optical path 25 is set by an oblique angle which cannot be detected by a light receiving element 23b. Then the detection of the LCD 2 in each stage in the cassette 1 of a carrying device 11 is stopped when a pair of tweezers 12 is carried to the taking-out port 13 of the cassette 1 to be detected by means of a Y-axis carrying section 18. Then the cassette 1 is elevated to the space between the light emitting and receiving sections 23a and 23b of a fixed transmission-type sensor 23. After elevating the cassette 1, the light emitting section 23a projects the light on the light receiving element 23a. The presence of the LCD 2 in each stage of the cassette 1 is recognized by means of a CPU after the light received by the light receiving element 23b is photoelectrically converted.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a translucent object detection device.

(Prior Art) In the manufacturing of liquid crystal displays, a detection device for a liquid crystal display (hereinafter abbreviated as LCD) is used in the process of taking out a liquid crystal display from a cassette containing it and transporting it to an inspection device. As shown in FIG. 5, an elevator (2) for raising and lowering a plurality of LCDs (2) stored in a cassette (ω) is provided, and a sensor (2) is provided at a position perpendicular to the side peripheral edge of the LCD (2).

In order to detect the LCD ■ in the cassette ω with this device, move up and down the elevator ■ to detect the light emitting part 0 of the sensor 0.
The irradiated light (2) is reflected by the side periphery of the LCD (2) and enters the light receiving element (2).

A configuration is generally used in which the light incident on the light receiving element (c) is stored in a storage device by the CPU of the control means as the detection position of the LCD (2).

This method involves irradiating the irradiation light (2) onto the side periphery of the LCD (2), but there has yet to be found anything that detects the irradiation light (2) by irradiating the back surface (10) of the LCD (2) rather than the front (0).

(Problem to be solved by the invention! I) However, in the conventional detection device, when the irradiation light (2) is irradiated onto the surface (on the side periphery of the LCD (2)), it is diffusely reflected by the surface (on the side periphery) and the light receiving element ■There are cases where no light is received. Also, if the LCD ■ in the cassette ω is not detected,
I couldn't take out this LCD ■.

It will remain in this cassette ω.

Then, there was a problem that the remaining LCD ■ had to be artificially transported, which led to a reduction in work efficiency.

The object of the present invention has been made in view of the above-mentioned problems of the conventional art. An object of the present invention is to provide an object detection device.

[Structure of the invention]

(Means for solving problems) The present invention relates to an apparatus for detecting a transparent object.

The present invention is characterized in that the irradiated light is obliquely crossed to the light-transmitting object, and the presence or absence of an optical path change due to refraction of the irradiated light at the light-transparent object is detected.

(Function) In a device that detects a translucent object, when the irradiation light is irradiated obliquely to the translucent object, the optical path of the irradiated light changes due to the refraction of the translucent object. The irradiated light-transmitting object can be detected.

(Embodiment) Hereinafter, an embodiment in which the light-transmitting object detection device of the present invention is applied to a transport device for transporting a liquid crystal display to an inspection section that performs inspections for disconnection and other issues will be described with reference to the drawings.

The external structure of the conveyance device of this embodiment will be explained with reference to FIG. 3. The same parts as those used in the conventional explanation will be explained using the same symbols. As is well known, LCDs are made of translucent glass substrates that face each other with a slight gap between them and are integrally formed, so since it is a translucent object, the presence or absence of this translucent object is always checked during automatic inspection. .

The transport device (11) is roughly divided into an elevator (2) for not moving up and down the cassette (ω) containing the LCD (2), and a mechanism called a bin set (12) for taking out the LCD (2) from the elevator (2).

The elevator (2) can be driven so that the cassettes (2), which are placed with the outlet (13) aligned in one direction, are moved up and down in the direction of arrow B. This drive control is a control means C
The drive motor (14) is rotated based on the command signal from the PU. By this rotation, the zero-order bin set (12), which has a directly connected pole screw shaft (15), drives the cassette (1) mounting table (16) provided on the top surface in vertical motion. The above-mentioned elevator ■ platform (16)
The LCD ■ is taken out from the cassette placed on the cassette.

The configuration of the bin set (12) is as follows: LC in the cassette ω
The take-out bar (17) enters between the LCD ■ in the cassette ω to take out the D■, and the take-out bar (17) reaches the position where each cassette ■ is placed in an independent elevator ■.
and a Y-axis conveyance section (18) that moves the Y-axis.

The ejection bar (17) is provided parallel to the LCD ■ surface, facing the ejection port (13) of the cassette ■, and enters into the slight gap between the LCD ■ stored in each stage to remove the LCD.
(2) It is designed to attract and take out.

The Y-axis conveying section (18) is provided on the bottom of the take-out bar (17), and moves in a direction parallel to each cassette (2) of the independent elevator (2) to move the take-out bar (17)
Then, the LCD ■ is taken out from each cassette ■.

The above Y-axis transport section (18) configuration is a transport device in this embodiment!
Two rails (2) laid on the base (19) of (11)
0) and can be driven by a Y-axis drive motor (21). In order to take out the LCD ■ from the cassette ■ sequentially and automatically inspect it using such a device,
It is necessary to recognize in advance the storage state of the LCD ■ in the cassette ω. This recognition automatically recognizes the LC for each stage of the cassette
It is necessary to recognize in advance the presence or absence of D■.

The translucent object detection device (22) for detecting the presence or absence of the LCD (2) in each stage in the cassette (ω) will be specifically explained with reference to FIG.

The elevator in which the force sector ■ is moved up and down (3 in Figure 3)
) on the mounting stand (16) of the cassette
A light emitting unit (23a), for example, an LED, which is the wax light source of the transmission type sensor (23), is arranged in the optical path above the surface facing the sensor (13).

Further, a light receiving element (23b) having a photoelectric conversion function, which is a light receiving source, is arranged in the downward optical path on the opposite side to the outlet (13) of the cassette (2). That is, the irradiation light (24) irradiated from the light emitting part (23a) is formed so that it irradiates diagonally to the LCD (2), and a light receiving element (23b) is provided in the straight path so that the light enters. There is. Therefore, in the LCD ■ storage stage in the cassette ω where the LCD ■ does not exist, the light emitting part (23a
) The irradiation light (24) emitted from the light receiving element (23b)
The light enters. This incident irradiation light (24) is photoelectrically converted into a non-existence information signal for LCD (2).

This signal is sent to the CPU (not shown). cpu
In this case, the absence of LCD ■ can be recognized.

The above describes the recognition when the number of stages in the cassette is 1, for example, a cassette that can store 25 sheets, and there is no LCD ■ on the n-6th stage from the bottom.First, the number of stages in the cassette, for example n
The case where the LCD ■ exists in the row will be explained with reference to FIG.

The irradiated light (24) emitted from the light emitting section (23a) obliquely enters the surface (2) of the LCD (2). The obliquely incident illumination light (24) is refracted by the LCD (2) and its optical path changes. Therefore, the irradiation light (24) cannot be made to enter the light receiving element (23b) as in the case where the LCD (2) is not present.

When the irradiation light (24) does not enter the light receiving element (23b), it is not photoelectrically converted (it becomes an LCD ■ presence information signal. This signal allows the CPU to recognize the presence of the LCD ■. It goes without saying that the above signal may be reversed.

The optical path and refraction of the obliquely incident illumination light will be specifically explained. L obliquely from the light emitting part (Z3a)
The irradiated light (24) incident on the CD (2) is refracted at a refraction angle, for example, Δ01 angle, according to the refractive index of the LCD (2), and is transmitted. This transmitted irradiation light (24) is emitted into the air from inside the LCD. When ejecting into this air.

According to the refractive index of air, the light is refracted at an angle of refraction, such as Δθ, and passes through.

The optical path (25) that obliquely enters the LCD (2) from the light emitting portion (23a) and the optical path (26) that exits into the air from the LCD (Z) maintain parallel paths and are deviated. The oblique angle is set to such an extent that the shift amount Δt of this deflection is not detected by the light receiving element (23b).

Next, the effect will be explained. First, the above-mentioned transport device (11
), the LCD ■ for each stage in the cassette ω is first detected by the Y-axis conveyance section (18).

Bin set (
12) is transported and stopped. Fixed through-beam sensor (
The cassette (2) is moved up and down between the light emitting section (23a) and the light receiving section (23b) of 23).

A light emitting section (23a) arranged above the outlet (13) of the cassette (2) irradiates the light receiving element (23b) with irradiation light.

The presence or absence of the LCD ■ at each stage of the cassette ω is determined by the CPU converting the incident light to the light receiving element (23b) into an L
Recognizes the presence or absence of CD■. l
In the above embodiment, the transmission type sensor (23) is fixed and the LC
Although the cassette (2) storing D (2) is moved up and down, the cassette (2) may be fixed and the transmission type sensor (23) may be moved up and down.

In the above embodiment, the presence or absence of the LCD ■ is determined by storing it in the cassette ■, but in this case, the LCD ■ is taken out from the cassette ω in a single wafer manner and the LCD ■ is detected while being conveyed to a set position. However, it is not limited to this.

In the above embodiment, the LCD ■ is taken out from the cassette ω using tweezers (12), but the LCD ■ may also be taken out using a belt conveyor (25) as shown in FIG.

(Effects of the Invention) According to the present invention, since the presence or absence of a change in the optical path due to refraction of irradiated light by a translucent object is detected, the presence of a translucent object can be easily detected and recognized. Furthermore, since the presence of a transparent object can be detected, automation becomes possible.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for explaining the characteristic configuration of the translucent object detection device of the present invention, and FIG. 2 is an explanatory diagram for explaining the configuration of the LCD and transmission sensor in FIG. 1. Fig. 3' is an explanatory external view explaining the external configuration of one embodiment in which the device shown in Fig. 1 is applied to a conveying device, and Fig. 4 shows another embodiment in which the device shown in Fig. 1 is applied to a belt conveying device. FIG. 5 is an explanatory diagram illustrating the relationship between a sensor and an LCD of a conventional translucent object detection device. 11... Conveyance device 13... Outlet 22...
・Translucent object detection device 23... Transmissive type sensor 24... Irradiation light Patent applicant Tokyo Electron Ltd. Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A device for detecting a translucent object, characterized in that the irradiation light is obliquely crossed to the translucent object, and the presence or absence of an optical path change due to refraction of the irradiation light at the translucent object is detected. Sexual object detection device.