JPH11287633A - Optical axis adjustment method and optical transmission device - Google Patents

Abstract

(57) [Problem] To provide an optical axis adjusting method capable of automatically adjusting an optical axis and an optical transmission device using the same. SOLUTION: In an optical transmission device constituted by a light emitting unit 1 and a light receiving unit 2, a light emitting circuit 6 and an optical axis XZ operation circuit 7 for swing control of the emission angle of laser light up, down, left and right. And the light receiving unit 2 is provided with
A light receiving circuit 12, a light receiving amount detecting circuit 13 for detecting a waveform amplitude value, a peak light amount detecting circuit 14 for monitoring the detected amplitude value and detecting and storing a maximum value, and a detected amplitude value and a maximum value of the amplitude value. A comparison circuit 15 for transmitting an optical axis coincidence signal when it is determined that the values coincide with each other is provided, and means 4 (electric wire) for transmitting the optical axis coincidence signal from the light receiving unit 2 to the light emitting unit 1 as an electric signal is provided. Was.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical axis adjusting method and an optical transmission device in an optical transmission device for transmitting a control signal or a video signal between a movable portion and a fixed control portion of various devices using a laser beam. And an electronic component mounting apparatus using the same.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 8-220405 discloses an example of a conventional optical transmission device using a visible semiconductor laser for laser light.
The one disclosed in Japanese Patent Application Laid-Open Publication No. H10-260, 1993 is known. 6 and 7 show a configuration of a portion for adjusting the optical axis of the optical transmission device. FIG. 6 shows the light emitting unit 31 and FIG. 7 shows the light receiving unit 32. 6 and 7, reference numeral 33 denotes a condenser lens;
Is an optical axis adjusting screw for adjusting the optical axis of the laser beam, and 35 is a fixing screw.

FIG. 8 shows a light emitting unit 31 and a light receiving unit 3.
FIG. 4 is a perspective view showing an optical axis adjustment method in the case where the laser light is used by reflecting the laser light by 90 degrees by using No. 2; Here, a reflecting mirror 36 changes the traveling direction of the laser light emitted from the light emitting unit 31 by 90 degrees by reflection. Reference numeral 37 denotes a jig for adjusting the optical axis of the laser beam from the light emitting unit 31, and is formed of a + mark plate.

[0004] The optical axis adjusting method is a method in which a laser beam emitted from a light emitting unit 31 is condensed by a condenser lens 33
The optical axis adjusting screw 3 of the light emitting unit 31
4 and the reflection mirror 36 are adjusted. And
It is checked using the + mark plate 37 whether or not the laser beam hits the center of the condenser lens 33.

[0005] Another conventional example is disclosed in Japanese Patent Application Laid-Open No. 5-28.
The thing described in 9003 gazette is known. As shown in FIG. 9, a lens barrel 41 for receiving and emitting light is connected to a linear motor 4.
The optical axis can be adjusted in the directions of arrows a and b by rotating at 2, 43.

[0006]

However, in the above-mentioned conventional optical axis adjustment methods shown in FIGS. 6 to 8, a plurality of screws are adjusted to adjust the optical axis, and a visual check is performed. If not, it is necessary to repeat the operation of adjusting the screw again to adjust the optical axis, and there is a problem that it takes a lot of trouble and time.

Further, the prior art shown in FIG. 9 has a problem that when the power is turned off, the lens barrel 41 becomes free, and it is necessary to align the optical axis for a long time again when the power is turned on.

In view of the above-mentioned conventional problems, the present invention provides an optical axis adjusting method capable of automatically adjusting the optical axis and maintaining the state, an optical transmission apparatus using the same, and an optical transmission apparatus using the same. It is an object of the present invention to provide an electronic component mounting apparatus to which the present invention is applied.

[0009]

According to the optical axis adjusting method of the present invention, a step of emitting a laser beam from a light emitting unit to a light receiving unit while changing an angle within an operating range in a vertical direction and a horizontal direction is provided. Receiving the received laser light by the light receiving unit and detecting the amplitude value; detecting and storing the maximum value of the amplitude value in each of the vertical and horizontal directions; and transmitting the laser light again in the vertical and horizontal directions. Emitting a laser beam while changing the angle to detect an amplitude value, and transmitting an optical axis coincidence signal to the light emitting unit when it is determined that the detected amplitude value matches the maximum value of the amplitude value, Holding the posture of the light emitting unit when the light emitting unit detects the optical axis coincidence signal.

An optical transmission device according to the present invention comprises a light emitting unit and a light receiving unit which are installed at a distance from each other, converts an electric signal into a laser beam, and transmits the signal in the air using the laser beam. In the transmission device, the light emitting unit is a light emitting circuit that converts an electric signal into an optical signal and emits the light signal toward the light receiving unit, and an optical axis XZ operation circuit that swings the emission angle of the laser light in the vertical and horizontal directions. The light receiving unit includes a light receiving circuit that converts a received light signal into an electric signal, a light receiving amount detecting circuit that detects an amplitude value of an electric signal waveform from the light receiving circuit, and monitors the detected amplitude value to determine a maximum value. A light quantity detection circuit for detecting and storing the peak light quantity; and a comparison circuit for transmitting an optical axis coincidence signal when it is determined that the detected amplitude value and the maximum value of the amplitude value match each other. axis The No. match signal is provided with a means for transmitting the light emitting Yunittohe electrical signal.

According to the optical axis adjusting method and the optical transmission device of the present invention, the light receiving amplitude value of the laser beam is detected and compared with the maximum value to detect the optical axis coincidence point. The axis can be adjusted.

According to the electronic component mounting apparatus of the present invention, in the electronic component mounting apparatus in which the mounting head is provided on the movable portion of the XY robot, the light emitting unit and the light receiving unit of the optical transmission device are connected to the mounting head. A mounting head unit and a control unit in the electronic component mounting apparatus, wherein the mounting unit and the control unit are arranged on a fixed portion of the Y robot and transmit and receive signals between the light emitting unit and the light receiving unit via at least one reflecting mirror. The transmission and reception of signals during the period can be performed with a simple and compact configuration, and the optical axis can be automatically adjusted, so that the adjustment work becomes easy.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which an optical transmission device using the optical axis adjusting method of the present invention is applied to an electronic component mounting device will be described below with reference to FIGS.

In FIG. 1 showing the configuration of the optical transmission device, 1
Denotes a laser light emitting unit, and 2 denotes a laser light receiving unit. Reference numeral 3 denotes a laser beam for transmitting an optical signal from the light emitting unit 1 to the light receiving unit 2, and reference numeral 4 denotes an electric wire for transmitting an electric signal from the light receiving unit 2 to the light emitting unit 1 when the optical axes coincide.

The light emitting unit 1 includes a light emitting circuit 6 for converting the transmission data 5 from an electric signal to an optical signal (laser light 3),
The emission angle of the laser beam 3 is controlled up, down, left and right, and
And an optical axis XZ operation circuit 7 for fixing the emission attitude angle of the laser beam 3 when receiving an optical axis coincidence signal from the light receiving unit 2 via the optical axis.

A motor driver 8 receives a command for the emission angle of the laser light 3 from the optical axis XZ operation circuit 7, an X-direction rotation non-excitation brake type motor 9 for rotating the laser light emission angle in the left and right direction, and And a Z-direction rotation non-excitation brake type motor 10 for rotating the laser beam emission angle in the vertical direction. FIG. 2 shows a mechanism for operating the laser beam emission angle. Reference numeral 19 denotes an X-direction rotary table which is reciprocated by the X-direction rotation non-excitation brake type motor 9, and the light emitting unit 1 is installed thereon. Reference numeral 20 denotes a Z-direction rotary table that is reciprocated by the Z-direction rotation non-excited brake type motor 10, and has a X
A directional rotation non-excitation brake type motor 9 is provided.

On the other hand, the light receiving unit 2 converts a light signal (laser light 3) into an electric signal and outputs received data 11, and a light receiving amount detecting circuit for detecting the amplitude of the electric signal waveform from the light receiving circuit 12. The circuit 13 detects and stores the maximum value of the amplitude value from the light receiving amount detection circuit 13 in each of the vertical direction and the horizontal direction when the laser beam emission angle is made to swing once within the operation range of the vertical direction and the horizontal direction. The peak light amount detection circuit 14 and the maximum value of the light reception amount amplitude value of the light reception amount detection circuit 13 and the amplitude value detected by the peak light amount detection circuit 14 when the laser light emission angle is again swung up and down and left and right directions respectively. And a comparison circuit 15 that transmits an optical axis coincidence signal to the optical axis XZ operation circuit 7 via the electric wire 4 when it is determined that both amplitude values match.

FIG. 3 shows an electronic component mounting apparatus to which the optical transmission device having the above configuration is applied. 21 is X- of the electronic component mounting apparatus.
An X-axis table 23 is provided on the Y-axis table 22 so as to be movable in the Y-axis direction.
3 is provided with a mounting head 24 so as to be movable in the X-axis direction. The light-emitting unit 1 is provided at one end of the Y-axis table 22 of the fixed portion, the light-receiving unit 2 is provided at the mounting head portion 24, and the position where the optical axes of the light-emitting unit 1 and the light-receiving unit 2 intersect on the X-axis table 23. Is provided with a reflecting mirror 25 for refracting the optical axis by 90 degrees. 26 is a substrate.

Next, the step of detecting the maximum amplitude of the amount of received laser light stored in the peak light amount detection circuit 14 will be described with reference to the flowchart of FIG. Step #
At 1, a laser beam 3 is emitted from the light emitting unit 1 to the light receiving unit 2. In steps # 2 to # 5, the motor driver 8 fixes one of the motor 9 with the X-direction rotation non-excitation brake and the motor 10 with the Z-direction rotation non-excitation brake, for example, the motor 10 with the Z-direction rotation non-excitation brake. ,
The motor 9 with the X-direction rotation non-excitation brake is operated to change the laser beam emission angle from the angle θmin within the operation range to θmax. In step # 3, the amplitude value is detected by the light reception amount detection circuit 13 while the laser beam emission angle is fluctuating, and the maximum value of the amplitude value detected in step # 4 is detected and stored. When the laser beam emission angle reaches .theta.max in step # 5, the maximum value (Smax) of the amplitude value detected in step # 4 is stored in step # 6. Subsequently, the maximum value of the amplitude value is similarly stored in the Z direction. In this way, the maximum value of the amplitude value (Smax) is stored for each of the vertical and horizontal directions of the laser emission angle. Here, the maximum value of the stored amplitude values indicates that the optical axis of the laser light emission angle is accurately projected.

Next, the step of determining the laser light emitting angle attitude of the light emitting unit 1 will be described with reference to the flowchart of FIG. In step # 11, the laser light 3 is emitted from the light emitting unit 1 toward the light receiving unit 2. Next, at step # 12, the laser beam emission angle is changed from the angle θmin within the operation range to θmax in the same manner as described above. In the meantime, in step # 13, the amplitude value of the received light amount detection circuit 13 is detected.
In step # 14, it is determined whether or not the detected amplitude value matches the maximum value (Smax) of the amplitude value obtained in the flowchart of FIG. If they do not match, the process returns to step # 12 to change the firing angle. If they match, the process shifts to step # 15 to transmit an optical axis coincidence signal to the optical axis XZ operation circuit 7 via the electric wire 4. Then, in step # 16, the optical axis XZ
The operation circuit 7 fixes the emission angle of the laser beam 3 with the non-excitation brake. In this way, once the laser light emission angle attitude is determined, the optical axis of the laser light emission angle is accurately maintained without performing the same optical axis adjustment even if the power is turned off thereafter.

According to the optical transmission device of the present embodiment, as described above, the laser beam 3 is emitted from the light emitting unit 1 by changing the emission angle, the light receiving unit 2 detects the light receiving amplitude value, and determines the maximum value. Since the optical axis coincidence point is detected by the comparison, the optical axis can be adjusted without manual operation. In the electronic component mounting apparatus according to the present embodiment, the optical transmission device is applied to signal transmission between the mounting head unit 24 and the fixed unit of the XY robot 21. The transmission and reception of signals between the control unit and the control unit can be performed with a simple and compact configuration, and the adjustment of the optical axis thereof can be automatically performed, so that the adjustment work is facilitated.

Further, as described above, in order to obtain the optical axis coincidence point, the position is collated with the peak value of the light amount.
Since the position is obtained only by the control that operates during θmax, it is possible to avoid an increase in cost due to the provision of the encoder as in the case of performing positioning control by providing an encoder or the like.

In the above embodiment, for simplicity of explanation, an example in which laser light is transmitted in one direction has been described. However, the light emitting unit 1 and the light receiving unit 2 are connected to each other, and the light emitting circuit 6 and the light receiving circuit 12 are connected to each other. Needless to say, it can be constituted by an optical signal transmission unit for transmitting and receiving bidirectionally.

[0024]

According to the optical axis adjusting method and the optical transmission apparatus of the present invention, as is apparent from the above description, the light emitting unit emits laser light by changing the emission angle, and the light receiving unit receives the light receiving amplitude. Since the optical axis coincidence point is detected by detecting the value and comparing it with the maximum value, the optical axis can be adjusted without manual intervention.

Further, according to the electronic component mounting apparatus of the present invention, the optical transmission device is applied to signal transmission between the mounting head unit and the fixed unit of the XY robot. The transmission and reception of signals during the period can be performed with a simple and compact configuration, and the optical axis can be automatically adjusted, so that the adjustment operation can be easily performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment of an optical transmission device of the present invention.

FIG. 2 is a front view of a laser light emission angle adjusting mechanism according to the embodiment.

FIG. 3 is a perspective view of an electronic component mounting apparatus to which the optical transmission device of the embodiment is applied.

FIG. 4 is a flowchart of a process of detecting a maximum amplitude of a received light amount in the embodiment.

FIG. 5 is a flowchart of a process of determining a laser light emission angle in the embodiment.

FIG. 6 is a perspective view of a conventional light emitting unit.

FIG. 7 is a perspective view of a conventional light receiving unit.

FIG. 8 is a perspective view showing an optical axis adjustment method in a conventional example.

FIG. 9 is a perspective view of an optical axis adjusting unit in another conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light emitting unit 2 light receiving unit 3 laser beam 4 electric wire 6 light emitting circuit 7 optical axis XZ operation circuit 12 light receiving circuit 13 received light amount detection circuit 14 peak light amount detection circuit 15 comparison circuit 21 XY robot 24 mounting head 25 reflection mirror

Claims (3)

[Claims] 1. A step of emitting a laser beam from a light emitting unit to a light receiving unit while changing an angle within an operation range in a vertical direction and a horizontal direction, and receiving the emitted laser light by the light receiving unit to obtain an amplitude value. Detecting the maximum value of the amplitude value in each of the vertical and horizontal directions, and storing the maximum value, and emitting the laser light again while changing the angle of the laser light in the vertical and horizontal directions again, and Transmitting an optical axis coincidence signal to the light emitting unit when it is determined that the detected amplitude value matches the maximum value of the amplitude value, and emitting light when the optical axis coincidence signal is detected by the light emitting unit. Maintaining the posture of the unit. 2. A light emitting unit and a light receiving unit are installed at a distance from each other, and convert an electric signal into laser light.
2. Description of the Related Art In an optical transmission device that transmits a signal in the air using laser light, a light emitting unit converts an electric signal into an optical signal and emits the light toward a light receiving unit. Optical axis X for swing control in the direction
A light receiving unit for converting a received light signal into an electric signal; a light receiving amount detecting circuit for detecting an amplitude value of an electric signal waveform from the light receiving circuit; and monitoring the detected amplitude value. A peak light amount detection circuit that detects and stores the maximum value, and a comparison circuit that transmits an optical axis coincidence signal when it is determined that the detected amplitude value and the maximum value of the amplitude value match each other, An optical transmission device comprising means for transmitting an optical axis coincidence signal from a light receiving unit to a light emitting unit as an electric signal. 3. An electronic component mounting apparatus in which a mounting head section is provided on a movable section of an XY robot, wherein the light emitting unit and the light receiving unit according to claim 2 are provided on a fixed section of the mounting head section and the XY robot. And an electronic component mounting apparatus configured to transmit and receive signals between the light emitting unit and the light receiving unit via at least one reflection mirror.