JP2002048639A - Characteristic measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a characteristic measuring apparatus by which the light intensity of a laser beam from a semiconductor laser unit and the distribution of the light intensity can be measured. SOLUTION: The characteristic measuring apparatus measures the characteristic of the laser beam 14 from the semiconductor laser unit 7 which is provided with a semiconductor laser 9, a lens 10 which converges a laser beam from the semiconductor laser 9 and an aperture 12 which shapes a laser beam from the lens 10. The apparatus is provided with a first light receiving element 1 which measures the light intensity of the laser beam from the unit 7 and a second light receiving element 2 which measures the distribution of the light intensity of the laser beam 14. The first and second elements 1, 2 are constituted so as to comprise a light receiving area which is larger than the area of the opening 12a of the aperture 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a characteristic measuring apparatus for measuring characteristics of laser light from a semiconductor laser unit in which a semiconductor laser, a lens and an aperture are integrally formed.

[0002]

2. Description of the Related Art Conventionally, there has been known a characteristic measuring apparatus for measuring a current-light output (IL) which is a basic characteristic of laser light from a semiconductor laser. This characteristic measuring device measures the light intensity of laser light from a semiconductor laser with a light receiving element while changing the current applied to the semiconductor laser. There is also known a characteristic measuring device for measuring an output distribution (FFP) which is a basic characteristic of laser light of a semiconductor laser. This characteristic measuring apparatus measures a light intensity distribution of laser light in a region where a distance from a light emitting point of a semiconductor laser is constant while moving a light receiving element.

[0003]

A scanning optical system for converging a laser beam as a light spot on a surface to be scanned and scanning the surface to be scanned is used in an image forming apparatus such as a laser printer or a digital copying machine. I have. Many of these scanning optical systems use a semiconductor laser as a light source. In this case, in the scanning optical system, the laser light from the semiconductor laser needs to be shaped by a lens, an aperture, and the like. In general, in a scanning optical system, a laser beam from a semiconductor laser which has been converted into a parallel, slightly divergent or slightly converged light beam by a coupling lens is shaped by an aperture. Here, the ratio (L2 / L1) of the light amount L2 of the laser light from the aperture to the light amount L1 of the laser light from the semiconductor laser is referred to as coupling efficiency.
In a conventional current-light output (IL) characteristic measuring apparatus, only a laser beam from a semiconductor laser is targeted, and a laser from a semiconductor laser unit in which a semiconductor laser, a coupling lens and an aperture are integrated. There is a problem that the characteristics of light cannot be measured. In addition, the conventional output distribution (FFP) characteristic measuring apparatus also has a problem that only the laser beam from the semiconductor laser is targeted, and the distribution of the light intensity of the laser beam from the semiconductor laser unit cannot be measured. An object of the present invention is to solve such a problem and to measure the light intensity and light intensity distribution of laser light from a semiconductor laser unit in which a semiconductor laser, a lens and an aperture are integrated. It is to provide a device.

[0004]

According to a first aspect of the present invention, there is provided a semiconductor laser, a lens for converging a laser beam from the semiconductor laser, and a laser beam from the lens. In a characteristic measuring device for measuring characteristics of a laser beam from a semiconductor laser unit having an aperture, a first light receiving element for measuring the light intensity of the laser beam from the semiconductor laser unit, and a laser beam from the semiconductor laser unit. A second light receiving element for measuring a light intensity distribution is provided, and the first and second light receiving elements are configured to have a light receiving area larger than an area of an opening of the aperture. According to a second aspect of the present invention, in the characteristic measuring apparatus according to the first aspect, the first light receiving element is formed of a single element light receiving element, and the second light receiving element is formed of a plurality of light receiving elements. It is characterized by being constituted by elements. According to a third aspect of the present invention, there is provided a characteristic measurement for measuring characteristics of a laser beam from a semiconductor laser unit having a semiconductor laser, a lens for converging a laser beam from the semiconductor laser, and an aperture for shaping the laser beam from the lens. In the apparatus, a first light receiving element for measuring light intensity of laser light from the semiconductor laser unit, a second light receiving element for measuring light intensity distribution of laser light from the semiconductor laser unit, and the second light receiving element A light-shielding plate disposed on a front surface of the light-receiving element and having an opening through which light passes, wherein the first and second light-receiving elements are each formed of a single-element light-receiving element;
And the second light receiving element is configured to have a light receiving area larger than the area of the opening of the aperture. According to a fourth aspect of the present invention, in the characteristic measuring apparatus according to the third aspect, the second light receiving element is positioned in a path of laser light from the semiconductor laser unit, and the light shielding plate and the second light receiving element are positioned. The light intensity distribution is measured by moving the positional relationship between a light receiving element and the semiconductor laser unit in a plane substantially perpendicular to the laser light. According to a fifth aspect of the present invention, in the characteristic measuring device according to any one of the first to fourth aspects, the first and second light receiving elements are supported by different first and second supports. By moving the first and second supports and selectively disposing the first and second light receiving elements in the path of laser light from the semiconductor laser unit, the light intensity and light intensity can be increased. It is characterized by measuring the distribution.

[0005] The invention according to claim 6 is the invention according to claims 1 to 4.
In the characteristic measuring apparatus according to any one of the claims, the first and second light receiving elements are supported on the same support, and the first and second light receiving elements are moved by moving the support. It is characterized in that the light intensity and the light intensity distribution are measured by selectively disposing them in the path of the laser light from the semiconductor laser unit. According to a seventh aspect of the present invention, there is provided a characteristic measurement for measuring characteristics of a laser beam from a semiconductor laser unit having a semiconductor laser, a lens for converging a laser beam from the semiconductor laser, and an aperture for shaping the laser beam from the lens. A light-receiving element for measuring the light intensity of the laser light from the semiconductor laser unit; and a light-shielding plate disposed on the front surface of the light-receiving element and having an opening for transmitting light, wherein the light-receiving element has a single-element structure. Wherein the light receiving element is configured to have a light receiving area larger than the area of the opening of the aperture, and the light shielding plate is movable.

[0006]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a characteristic measuring device according to the first embodiment of the present invention. FIG.
FIG. 2 is a partially cutaway side view showing a semiconductor laser unit in the characteristic measuring device of FIG. 1. As shown in FIG.
The characteristic measuring device according to the first embodiment of the present invention includes the first
And the second light receiving element 2.
The first light receiving element 1 is supported by a first support 3. The second light receiving element 2 is supported by a second support 4. The first support 1 is configured to be movable by first moving means 5 such as an automatic stage. The second support 2 is configured to be movable by a second moving means 6 such as an automatic stage. The first light receiving element 1 measures the light intensity of the laser light from the semiconductor laser unit 7.
The second light receiving element 2 measures the light intensity distribution of the laser light from the semiconductor laser unit 7. When the first and second supports 3 and 4 are moved by the first and second moving means 5 and 6, the first and second light receiving elements 1 and 2 emit laser light from the semiconductor laser unit 7. And a retreat position not receiving the laser beam. The semiconductor laser unit 7 is fixed on the measuring head 8. As shown in FIG. 2, the semiconductor laser unit 7 includes a semiconductor laser 9 and a collimating lens 1.
0, an outer cover 11 and an aperture 12. The semiconductor laser 9 is fixed on the measuring head 8. The outer cover 11 is formed by connecting two cylindrical bodies having different sizes in a row. The outer cover 11 is fixed on the measuring head 8 so as to cover the semiconductor laser 9. A collimator lens 10 is arranged inside the outer cover 11 so as to be located above the semiconductor laser 9. The exterior cover 11 has an opening at the upper end.
An aperture 12 is provided in the opening of the exterior cover 11. The aperture 12 has an opening 12a substantially at the center. The semiconductor laser 9 is connected to a driving device (not shown). This drive device drives the semiconductor laser 9 by applying electric power. The laser light 13 from the semiconductor laser 9 is made substantially collimated by the collimating lens 10, and converged by the aperture 12. The laser 14 light passing through the opening 12a of the aperture 12 is
The first light receiving element 1 or the second light receiving element
Are irradiated on the light receiving element 2. The first and second light receiving elements 1 and 2 are configured to have a light receiving area larger than the area of the opening 12a of the aperture 12 of the semiconductor laser unit 7.

The first light receiving element 1 is constituted by a light receiving element having a single element structure such as a PD (photodiode). The first light receiving element 1 can measure the light intensity of the laser light from the semiconductor laser unit 7. The first light receiving element 1 has a light receiving area larger than the area of the opening 12a of the aperture 12 to receive substantially parallel light from the aperture 12 at one time. The first light receiving element 1 can measure the light intensity of the laser light 14 because the laser light 14 from the aperture 12 is almost parallel light even when the laser light 14 is slightly divergent light. The second light receiving element 2 is constituted by a light receiving element having a multiple element structure such as a CCD. The second light receiving element 2 can measure the light intensity distribution of the laser light 14 from the semiconductor laser unit 7. The second light receiving element 2 includes an aperture 1
Aperture 1 to receive substantially parallel light from 2 at a time
The light receiving area is larger than the area of the second opening 12a. The second light receiving element 2 can measure even when the laser light from the aperture 12 is slightly divergent light because it is almost parallel light. FIG. 3 is a diagram illustrating an example of the light intensity distribution of the laser light from the semiconductor laser unit 7. The first light receiving element and the second light receiving elements 1 and 2 are connected to a control operation device (not shown). Further, a display device (not shown) is connected to the control arithmetic device. The control arithmetic unit receives the output of the first light receiving element 1, calculates the light intensity, and causes the display device to display the light intensity. Further, the control arithmetic unit receives the output of the second light receiving element 2, calculates the light intensity distribution, and displays it on the display device.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 4 is a perspective view showing a characteristic measuring device according to the second embodiment of the present invention. In the second embodiment of the present invention, the same components as those in the first embodiment of the present invention are denoted by the same reference numerals.
As shown in FIG. 4, the characteristic measuring device according to the second embodiment of the present invention has a first light receiving element 1 and a second light receiving element 2. The first light receiving element 1 is supported by a first support 3. The second light receiving element 2 is supported by a second support 4. The first support 1 is configured to be movable by first moving means 5 such as an automatic stage. The second support 4 is configured to be movable by a second moving means 6 such as an automatic stage. Further, the second moving means 6 is configured to be movable by the third moving means 15. The first light receiving element 1 measures the light intensity of the laser light 14 from the semiconductor laser unit 7. The second light receiving element 2 measures the light intensity distribution of the laser light 14 from the semiconductor laser unit 7. When the first and second supports 3 and 4 are moved by the first and second moving means 5 and 6, the first and second light receiving elements 1 and 2 are moved.
Are selectively arranged at a measurement position for receiving the laser light 14 from the semiconductor laser unit 7 and at a retreat position not receiving the laser light. As shown in FIG.
As shown in FIG. 5, a light shielding plate 16 is provided. The light shielding plate 16 has an opening 16a through which light passes. The light shielding plate 16 is fixed to the second support 4 and is integrated with the second light receiving element 2. In the second embodiment of the present invention, the second light receiving element 2 is constituted by a light receiving element having a single element structure such as a PD (photodiode). In the characteristic measuring device according to the second embodiment of the present invention, the second moving means 6 and the third moving means 15
By moving the second light receiving element 2 and the light shielding plate 16 at minute intervals in a plane substantially perpendicular to the laser beam 14 from the semiconductor laser unit 7, the light intensity at each position is measured as shown in FIG. A light intensity distribution can be obtained. Other configurations and operations of the second embodiment of the present invention are the same as those of the first embodiment of the present invention.

Next, a third embodiment of the present invention will be described in detail with reference to the drawings. FIG. 6 is a partially cutaway front view showing a characteristic measuring device according to a third embodiment of the present invention. In the third embodiment of the present invention, the same components as those in the first embodiment of the present invention are denoted by the same reference numerals. As shown in FIG. 6, the characteristic measuring device according to the third embodiment of the present invention has a first light receiving element 1 and a second light receiving element 2. The first light receiving element 1 and the second light receiving element 2 are supported by the same first support 3. The first support 3 is configured to be movable by a first moving means 5 such as an automatic stage. Other configurations and operations of the third embodiment of the present invention are the same as those of the first embodiment of the present invention. Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings. FIG.
FIG. 9 is a partially cutaway front view showing a characteristic measuring device according to a fourth embodiment of the present invention. In the fourth embodiment of the present invention, the same components as those in the second embodiment of the present invention are denoted by the same reference numerals. As shown in FIG. 7, the characteristic measuring device according to the fourth embodiment of the present invention comprises:
It has a first light receiving element 1 and a second light receiving element 2. The first light receiving element 1 and the second light receiving element 2 are supported by the same first support 3. On the front surface of the second light receiving element 2, a light shielding plate 16 is arranged. Light shield 16
Has an opening 16a through which light passes. Light shield 16
Are fixed to the first support 3 and are integrated with the second light receiving element 2. The first support 3 is configured to be movable by a first moving means 5 such as an automatic stage.
Other configurations and operations of the fourth embodiment of the present invention are the same as those of the second embodiment of the present invention.

Next, a fifth embodiment of the present invention will be described in detail with reference to the drawings. FIG. 8 is a partially cutaway side view showing a characteristic measuring device according to a fifth embodiment of the present invention. In the fifth embodiment of the present invention, the same components as those in the third embodiment of the present invention are denoted by the same reference numerals. As shown in FIG. 8, the characteristic measuring device according to the fifth embodiment of the present invention has a first light receiving element 1 and a second light receiving element 2. The first light receiving element 1 and the second light receiving element 2 are supported by the same support 17. The support 17 is configured to be rotatable by moving means (not shown) such as an automatic stage. The fifth of the present invention
In the embodiment of the present invention, the first and second light receiving elements 1 and 2 are
It is selectively disposed at a measurement position for receiving the laser light 14 from the semiconductor laser unit 7 and at a retreat position not receiving the laser light. Other configurations and operations of the fifth embodiment of the present invention are the same as those of the third embodiment of the present invention. Next, a sixth embodiment of the present invention will be described in detail with reference to the drawings. FIG. 9 is a partially cutaway side view showing a characteristic measuring device according to a sixth embodiment of the present invention.
In the sixth embodiment of the present invention, the same components as those in the fourth embodiment of the present invention are denoted by the same reference numerals. As shown in FIG. 9, the characteristic measuring device according to the sixth embodiment of the present invention has a first light receiving element 1 and a second light receiving element 2. First light receiving element 1 and second light receiving element
Are supported by the same support 17. On the front surface of the second light receiving element 2, a light shielding plate 16 is arranged. The light shielding plate 16 has an opening 16a through which light passes. The light shielding plate 16 is fixed to the support 17 and is integrated with the second light receiving element 2. The support 17 is configured to be rotatable and movable by a moving means (not shown) such as an automatic stage. In the sixth embodiment of the present invention, the first and second light receiving elements 1 and 2 receive the laser beam 14 from the semiconductor laser unit 7 at the measurement position by rotating the support 17 by the moving means. And selectively disposed at a retracted position not receiving the laser beam. Other configurations and operations of the sixth embodiment of the present invention are the same as those of the fourth embodiment of the present invention.

Next, a seventh embodiment of the present invention will be described in detail with reference to the drawings. FIG. 10 is a partially cutaway front view showing a characteristic measuring device according to a seventh embodiment of the present invention. FIG. 11 is a partially cutaway front view for explaining the operation of the characteristic measuring device according to the seventh embodiment of the present invention. In the seventh embodiment of the present invention, the same components as those of the second embodiment of the present invention are denoted by the same reference numerals. As shown in FIGS. 10 and 11, the characteristic measuring device according to the seventh embodiment of the present invention has a first light receiving element 1 and a light shielding plate 16. The first light receiving element 1 is fixed to a first support 3. The light shielding plate 16
It is supported by a second support 18. First support 1
Is configured to be movable by the moving means 19. The second support 18 is configured to be movable by the moving means 19. The light shielding plate 16 is movably disposed on the front surface of the first light receiving element 1. The light shielding plate 16 has an opening 16a through which light passes. When the moving means 19 moves the first and second supports 3 and 18, the first light receiving element 1 and the light shielding plate 16 can be selectively arranged at the measurement position and the retreat position. As shown in FIG.
When the light receiving element 1 and the light shielding plate 16 are arranged, the first
The light intensity of the laser beam 14 from the semiconductor laser unit 7 can be measured by the light receiving element 1. As shown in FIG. 11, when the first light receiving element 1 and the light shielding plate 16 are arranged, the light intensity distribution of the laser light 14 from the semiconductor laser unit 7 is reduced by the first light receiving element 1 and the light shielding plate 16. Can be measured. Other configurations and operations of the seventh embodiment of the present invention are the same as those of the second embodiment of the present invention.

[0012]

As described above, according to the first aspect of the present invention, both the light intensity and the light intensity distribution of the laser light from the semiconductor laser unit can be measured by one characteristic measuring device. Further, according to the invention described in claim 2, both the light intensity and the light intensity distribution of the laser light from the semiconductor laser unit can be measured by one characteristic measuring device, and the first light intensity measuring first device is used. By using a light receiving element having a single element structure as the light receiving element, it is possible to accurately measure light intensity with a low-cost and simple circuit configuration and to cope with a semiconductor laser unit having a wide irradiation range. According to the second aspect of the present invention, the light intensity distribution can be measured in a short time by using a light receiving element having a multiple element structure such as a CCD as the second light receiving element for measuring the light intensity distribution. Become. According to the third aspect of the present invention, both the light intensity and the light intensity distribution of the laser light from the semiconductor laser unit can be measured by one characteristic measuring device, and the second characteristic for measuring the light intensity distribution can be measured. By using a light receiving element having a single element structure as the light receiving element and arranging a light-shielding plate having an opening in front of the second light receiving element, it is possible to measure the light intensity distribution with a simple circuit configuration at low cost. Yes,
In addition, it can correspond to a semiconductor laser unit having a wide irradiation range. According to the fourth aspect of the present invention, both the light intensity and the light intensity distribution of the laser light from the semiconductor laser unit can be measured by one characteristic measuring device, and the second light receiving element can be used as a semiconductor laser. Since it is positioned in the path of the laser light from the unit and the positional relationship between the light shielding plate, the second light receiving element and the semiconductor laser unit is moved in a plane substantially perpendicular to the laser light, the light intensity distribution is measured. The light intensity distribution can be measured within the range and the resolution.
According to the fifth aspect of the present invention, both the light intensity and the light intensity distribution of the laser light from the semiconductor laser unit can be measured by one characteristic measuring device, and the first and second light receiving elements Are supported on different first and second supports, and the first and second supports are moved to selectively dispose the first and second light receiving elements in the path of the laser light from the semiconductor laser unit. Accordingly, since the light intensity and the light intensity distribution are measured, the moving means can be set for each light receiving element, and the light intensity and the light intensity distribution can be measured without complicating the positioning control of the light receiving element.

Further, according to the invention described in claim 6, 1
One characteristic measuring device can measure both the light intensity and the light intensity distribution of the laser light from the semiconductor laser unit, supporting the first and second light receiving elements on the same support,
Since the light intensity and the light intensity distribution are measured by moving the support and selectively disposing the first and second light receiving elements in the path of the laser light from the semiconductor laser unit, the moving means of the light receiving elements And light intensity and light intensity distribution can be measured without complicating the mechanism. According to the invention of claim 7, both the light intensity and the light intensity distribution of the laser light from the semiconductor laser unit can be measured by one characteristic measuring device, and the laser light from the semiconductor laser unit can be measured. A light-receiving element for measuring light intensity, and a light-shielding plate disposed on the front surface of the light-receiving element and having an opening for transmitting light, the light-receiving element is configured by a light-receiving element having a single-element structure, and the light-receiving element is The light-shielding plate is configured to have a light-receiving area larger than the area of the aperture of the aperture, and the light-shielding plate is movable, so that the light intensity and the light intensity distribution can be measured with a single light-receiving element.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a characteristic measuring device according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway side view showing a semiconductor laser unit in the characteristic measuring device of FIG.

FIG. 3 is a diagram showing an example of a light intensity distribution of laser light from a semiconductor laser unit.

FIG. 4 is a perspective view showing a characteristic measuring device according to a second embodiment of the present invention.

5 is a diagram showing a light receiving element and a light shielding plate in the characteristic measuring device of FIG.

FIG. 6 is a partially cutaway front view showing a characteristic measuring device according to a third embodiment of the present invention.

FIG. 7 is a partially cutaway front view showing a characteristic measuring device according to a fourth embodiment of the present invention.

FIG. 8 is a partially cutaway side view showing a characteristic measuring device according to a fifth embodiment of the present invention.

FIG. 9 is a partially cutaway side view showing a characteristic measuring device according to a sixth embodiment of the present invention.

FIG. 10 is a partially cutaway front view showing a characteristic measuring device according to a seventh embodiment of the present invention.

FIG. 11 is a partially cutaway front view for explaining the operation of a characteristic measuring device according to a seventh embodiment of the present invention.

[Explanation of symbols]

1 first light receiving element, 2 second light receiving element 2, 3 first
Support, 4 second support, 5 first moving means, 6
2nd moving means, 7 semiconductor laser unit, 8 measuring head, 9 semiconductor laser, 10 collimating lens, 11 exterior cover, 12 aperture, 12a opening, 15 third moving means, 16 light shielding plate, 16a
Openings, 17 supports, 18 supports, 19 means of movement.

Claims (7)

[Claims] 1. A characteristic measuring apparatus for measuring characteristics of a laser beam from a semiconductor laser unit having a semiconductor laser, a lens for converging a laser beam from the semiconductor laser, and an aperture for shaping the laser beam from the lens. A first light receiving element for measuring the light intensity of the laser light from the semiconductor laser unit; and a second light receiving element for measuring the light intensity distribution of the laser light from the semiconductor laser unit, wherein the first and second light receiving elements are provided. A characteristic measuring device, wherein the light receiving element is configured to have a light receiving area larger than an area of the opening of the aperture. 2. The characteristic measuring device according to claim 1, wherein said first light receiving element is constituted by a light receiving element having a single element structure, and said second light receiving element is constituted by a light receiving element having a plurality of element structures. A characteristic measuring device characterized in that: 3. A characteristic measuring apparatus for measuring characteristics of a laser beam from a semiconductor laser unit having a semiconductor laser, a lens for converging a laser beam from the semiconductor laser, and an aperture for shaping the laser beam from the lens. A first light receiving element for measuring the light intensity of the laser light from the semiconductor laser unit, a second light receiving element for measuring the light intensity distribution of the laser light from the semiconductor laser unit, and a front surface of the second light receiving element A light-shielding plate having an opening through which light is transmitted, wherein the first and second light-receiving elements are constituted by light-receiving elements having a single-element structure,
And a second light receiving element configured to have a light receiving area larger than an area of the opening of the aperture. 4. The characteristic measuring device according to claim 3, wherein said second light receiving element is positioned in a path of laser light from said semiconductor laser unit, and said light shielding plate, said second light receiving element and A characteristic measuring device for measuring a light intensity distribution by moving a positional relationship of a semiconductor laser unit in a plane substantially perpendicular to the laser beam. 5. The characteristic measuring device according to claim 1, wherein the first and second light receiving elements are supported by different first and second supports, and the first and second light receiving elements are supported by different first and second supports. The light intensity and the light intensity distribution are measured by moving the first and second supports and selectively disposing the first and second light receiving elements in the path of the laser light from the semiconductor laser unit. A characteristic measuring device characterized by the above-mentioned. 6. The characteristic measuring device according to claim 1, wherein the first and second light receiving elements are supported on a same support, and the support is moved to move the support. A characteristic measuring device for measuring light intensity and light intensity distribution by selectively disposing first and second light receiving elements in a path of laser light from the semiconductor laser unit. 7. A characteristic measuring apparatus for measuring characteristics of a laser beam from a semiconductor laser unit having a semiconductor laser, a lens for converging a laser beam from the semiconductor laser, and an aperture for shaping the laser beam from the lens. A light-receiving element for measuring the light intensity of the laser light from the semiconductor laser unit, and a light-shielding plate disposed on the front surface of the light-receiving element and having an opening for transmitting light, the light-receiving element is a light-receiving element having a single-element structure. A characteristic measuring apparatus, wherein the light receiving element is configured to have a light receiving area larger than an area of an opening of the aperture, and the light shielding plate is movable.