JPH0658205B2 - Optical inspection device - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an optical inspection apparatus such as a projector or a tool microscope.

(Background of the Invention) The object to be inspected is transmitted and illuminated in a projector, a tool microscope, etc.,
When the measurement is performed by enlarging with the imaging optical member, the transmitted illumination is generally telecentric illumination, and therefore, even if there is a slight defocus, the measurement is performed correctly, and therefore the transmitted illumination is generally used. However, in principle, the measurement of the object to be inspected is performed on the surface, so when measuring an object to be inspected such that the end face is reflected, it is more accurate to focus on the surface of the object to be measured. To be measured. For this reason, when focusing is performed, the reflection illuminator is activated to perform reflection illumination, and the top reflection illuminator that is focused while observing the surface image is deactivated, and the transmission illumination device is activated to perform measurement with transmitted illumination. Is common. However, in the conventional device, the illumination device and the focusing device for focusing are considered as independent devices, and the operation of operating the reflection illumination device must be performed each time focusing is performed. However, it was often troublesome to perform measurement under undesired conditions by focusing with transmitted illumination or performing measurement with reflected illumination. Therefore, there is a drawback that the measurement is performed without the best accuracy of the device.

(Object of the invention) It is an object of the present invention to solve this drawback and to obtain an optical inspection apparatus that can always perform measurement in the best condition.

(Summary of the Invention) The technical point of the present invention is to automatically perform reflective illumination at the time of focusing by interlocking an illumination device and a focusing device.

(Embodiment) FIG. 1 is a block diagram showing an optical inspection device according to an embodiment of the present invention.

An object 2 to be inspected on the stage 1 is magnified and observed by an imaging optical device 8 having an objective lens 3, a half mirror 4, total reflection mirrors 5 and 6, and a projection screen 7.

The reflection illumination device 9 includes a reflection illumination command switch 90, OR gates 91 and 92 that pass a command signal generated when the reflection illumination command switch 90 is turned on, and a drive device 93 that lights a light source 94 according to a command signal from the OR gate 92. The reflected illumination light from the light source 94 is reflected by the half mirror 4 to reflect and illuminate the object 2 to be inspected.

The transmissive illumination device 10 includes a transmissive illumination command switch 100 and a drive device 101 that lights a light source 102 according to a command signal generated by turning on the transmissive illumination command switch 100. The transmitted illumination light from the light source 102 illuminates the object 2 to be inspected by the condenser lens 11 and the total reflection mirror 12.

The focusing device 13 includes a focusing command switch 130, a motor driving device 131 that drives the motor 132 by a focusing command signal generated by turning on the focusing command switch 130, and rotation of the motor 132 into vertical movement of the stage 1. And a vertical movement device 133 for moving the stage. The focus command switch 132 has, for example, a switch for raising the stage 1 and a switch for lowering the stage 1. The focus command signal includes a command signal for raising and a command signal for lowering.

The operating device 14 shares the OR gates 91 and 92 in order to transmit the focus command signal of the focus command switch 130 as a command signal to the drive device 93 of the reflective illumination light source 94, whereby the focus command signal is OR gated. While transmitting to the drive device 93 through 91, 92, after the focus command signal disappears, it has a timer 140 for turning on the reflection illumination light source 94 for a predetermined time,
The signal from the timer 140 is transmitted to the driving device 93 through the OR gate 92.

With such a structure, when a focus command is issued by turning on the focus command switch 130, the focus command signal enters the drive device 93 through the OR gates 91 and 92, so that the command signal from the reflected illumination command switch 90 is transmitted. Regardless of whether it occurs, the reflected illumination light source 94 is turned on, the motor 132 is rotated through the motor drive device 131, and the stage 1 is moved up and down via the up-and-down movement device 133. Therefore, the measurer can focus electrically by observing the magnified image of the object 2 to be inspected on the screen 7 with reflection illumination. When the focus is confirmed and the focus command switch 130 is turned off, the stage 1
Is stopped, and if the reflected light command switch 90 is off after a predetermined time set by the timer 140, the light source for reflected light is
94 goes out.

The transmitted illumination command switch 100 may be always turned on, and the transmitted illumination and the reflected illumination may be used together during the focusing operation. Alternatively, when the focused instruction switch 130 is turned on, the transmitted illumination command switch 100 has a command signal. In order not to be transmitted to the driving device 101, a prohibiting circuit or a switch which is activated by a focus command signal can be provided between the two.

Further, the reflected illumination command switch 90 becomes unnecessary if all measurements are performed by transmitted illumination, but in some cases the shape of the surface of the DUT 2 does not appear in transmitted illumination. In some cases, the measurement may be performed with reflected illumination, so it has some utility value.

In the above embodiments, the switch is used as the command member, but any device that can generate the command signal may be used.

Further, in the above-mentioned embodiments, a projector for projecting an object to be inspected on a screen is used as an optical inspection device, but the same applies to a microscope for observing an image of the object to be inspected by an eyepiece. Needless to say.

(Effect of the invention) As described above, according to the present invention, the focusing instruction member for instructing the focusing operation also serves as the instruction member for the reflection illumination, so that the reflection illumination is always performed at the time of focusing, Accurate focusing becomes possible and accurate measurement becomes possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an optical inspection device according to an embodiment of the present invention. (Explanation of symbols of main parts) 1 ... Stage, 8 ... Imaging optical device, 9 ... Reflective illumination device, 10
... Transmissive illumination device, 13 ... Focusing device, 14 ... Actuating device.

Claims (1)

[Claims] 1. A stage, an image forming optical device for forming an image of an object to be inspected on the object stage, a reflection illuminating device for illuminating the object to be inspected, and turning on the reflection illuminating device. A reflective illumination command signal for outputting a reflective illumination command signal, a transmissive illumination device for transilluminating the object to be inspected, a focusing device for focusing the imaging optical device on the surface of the object to be inspected, and the focusing. A focusing command member that outputs a focusing command signal that turns on both the device and the reflective illumination device; and the focusing command signal when the reflective illumination device is turned on by the output of the focusing command signal. An optical inspection device comprising: a timer unit for turning on the reflection illumination device for a predetermined time even if the output of is stopped.