JPH0452528A - Measuring method of light beam - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a method for measuring the position (optical axis) and diameter of a light beam of a semiconductor laser provided in a laser printer, for example. Concerning beam measurement methods.

(Prior art) Conventionally, in order to evaluate whether a light beam emitted from a semiconductor laser meets a predetermined standard, it is necessary to measure two things: the position (optical axis) of the light beam and the diameter of the light beam. be.

For example, when measuring the position and diameter of a light beam as a test result of changes over time, environmental changes, etc., conventional methods use a photo sensor to measure the position of the light beam, that is, the height of the optical axis. About C
Individual measurements were taken using a CD camera or the like.

(Problem to be Solved by the Invention) However, when a photo sensor is used to measure the optical axis of a light beam, the worker must use a micro head or the like to measure the position of the photo sensor, making the work difficult. In addition to being time-consuming, the measurement accuracy was also poor.

Furthermore, since the resolution of the CCD camera is poor, there is also the problem that the diameter of the light beam cannot be accurately measured.

Furthermore, since the position of the light beam and the diameter of the light beam were each measured separately, there was a problem of poor measurement efficiency.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for measuring a light beam that can simultaneously measure the position (optical axis) of a light beam and the diameter of the light beam with high precision.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention generates a light beam from a light emitter, transmits a part of this light beam by a light splitting means, and transmits the other part. The light that has passed through the light splitting means is received by a line sensor to measure its optical axis, and the light reflected from the light splitting means is received by an analog sensor and its diameter is determined by electrical power. It is characterized by being measured on a time axis.

(Function) By having the line sensor receive the light that has passed through the light splitting means, the optical axis can be measured without bothering the worker, and the light reflected from the light splitting means can be received by the analog sensor. By measuring the diameter using electrical power and time axis, the diameter of the light beam can be measured with high precision.
Moreover, by dividing the light beam into two by the light splitting means and having the line sensor and the analog sensor receive the light, the position and diameter of the light beam can be measured simultaneously.

(Example) The present invention will be described below with reference to an example shown in the drawings.

In the figure, 1 is a holder, and a light source unit 2 is held in this holder. The light source unit 2 is equipped with a semiconductor laser 3 as a light emitter.

A reflecting mirror 4 for scanning the light is rotatably provided in the optical path of the light beam generated from the semiconductor laser 3, and a half mirror as a photo-decomposing means is provided in the optical path of the light beam reflected from the reflecting mirror 4. -5 and line sensor 6 are arranged. As shown in FIG. 2, the line sensor 6 includes a photodiode type semiconductor device detection element 6a...
It is placed on a movable stage 11.

Further, a photosensor 7 as an analog sensor is provided in the optical path of the light beam reflected by the half mirror 5. The photo sensor 7 includes the line sensor sensor 6 and the photo sensor 7 placed on a movable stage 12.
is connected to the control box 12 via a signal path 8.9.

Thus, the light beam generated from the semiconductor laser 3 is irradiated onto the reflecting mirror 4, is reflected from the reflecting mirror 4, and is scanned in the horizontal direction. A part of this light beam passes through the half mirror 5, and the rest passes through the half mirror 5.
It is reflected from the beam and split into two.

The light beam passing through the half mirror 5 is sent to the line sensor 6
The light is received by the semiconductor device detection element 6a of the half mirror 5.
The light beam reflected from the photo sensor 7 is received by the photo sensor 7.

The position of the first beam received by the semiconductor device detection element 6a of the line sensor 6, that is, the optical axis thereof, is measured and displayed on the display section 10a of the control box 10.

Further, the diameter of the light beam received by the photosensor 7 is measured and displayed on the display section 10b of the control box 10.

That is, when a light beam is received by the photosensor 7, as the light beam scans, the amount of light received by the photosensor 7 gradually increases, and the electrical power increases, as shown in the graph of FIG. .

Then, when the light beam is further scanned, the amount of light received by the photosensor 7 is gradually reduced, and the electrical power is reduced. For example, the length k of a straight line connecting points a and b on the graph of FIG. 3 is displayed on the display section 10'b of the control box 1° as the diameter of the light beam.

As mentioned above, the light/axis of the light beam is detected by the line sensor 6.
Since it is detected and measured by the semiconductor device detection element 6a of
Measurement accuracy can be improved compared to when measurements are performed manually by workers and mechanically.

Furthermore, since the light beam is detected by the photosensor 7 and the diameter of the light beam is measured based on the electrical power and time axis, highly accurate measurement is possible.

Further, since the light beam is divided into two by the half mirror 5 and is received by the semiconductor device detection element 6a of the line sensor 6 and the photosensor 7, the position and diameter of the light beam can be measured simultaneously, improving measurement efficiency.

In addition, by using it not only in the measurement of the light beam but also in the adjustment stage, the assembly and adjustment work of the optical unit can be significantly facilitated.

In addition, optical means corresponding to the light beam (Fθ lens,
If a collimator lens, etc.) is placed in the middle, it becomes possible to measure and evaluate the entire optical unit.

As described above, in this embodiment, a line sensor using a photodiode type semiconductor device detection element 6a is used for optical axis measurement, and a photo sensor 7 is used as an analog sensor for beam system measurement. Other light receiving elements and methods may be used for each measurement.

[Effects of the Invention] As explained above, the present invention has the effect of being able to measure the optical axis and diameter of a light beam with high precision, and simultaneously measuring the optical axis and diameter of a light beam, thereby improving work efficiency. play.

[Brief explanation of the drawing]

Figure 1 d - A configuration diagram showing a measuring device for measuring the position and diameter of a light beam, which is an embodiment of Ming. Figure 2 is a front view showing its line sensor, and Figure 3 is the photo sensor of Figure 1. FIG. 2 is a graph diagram showing the power when receiving a light beam in relation to time. 3... Semiconductor laser (light emitter), 5... Half mirror (light splitting means), 6a... Semiconductor device detection element, 6
...Line sensor 7...Photo sensor (analog sensor). Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 3

Claims (1)

[Claims] A light beam is generated from a light emitting body, a part of this light beam is transmitted through a light splitting means, and the other part is reflected to be split into two, and the light that has passed through the light splitting means is received by a line sensor to generate the light. A method for measuring a light beam, comprising: measuring the axis, having an analog sensor receive the light reflected from the light splitting means, and measuring its diameter in terms of electrical power and time axis.