JPS60129724A - Optical laser scanning device - Google Patents

Abstract

PURPOSE:To measure the quantity of laser light easily while holding an optical device in a sealed structure by arranging the optical device in the sealed structure, and providing a movable reflecting mirror which can be switched freely between a light source and a rotary polygon mirror. CONSTITUTION:A laser light source device 2, rotary polygon mirror M, and condenser lenses 6-6'' are enclosed in a structure member 1, the movable reflecting mirror 4 is supported in a space 1c rotatably around a rotating shaft 5, and a photodetecting element 8 is fitted to a transparent window member 7. When the quantity of laser light is measured, the mirror 4 is rotated to a position (a) and the quantity of laser light is measured by the photodetecting element 8. Consequently, the quantity of laser light is measured easily while the sealed state of the optical device is held, and the entry of dust in the device is prevented to maintain excellent image forming performance for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser optical device, and more particularly to a laser scanning optical device configured to use a movable reflection mirror to guide laser light to a light receiving element in order to measure the amount of laser light.

As shown in FIG. 1, in the scanning optical device, a light source device 2 is attached to a structural member 1 of a main body of the laser optical device. Inside the structural member l, there is a rotating polygon mirror M and condensing lenses 6, 6', 6.
# is placed. The laser beam emitted from the light source device 2 is focused by a lens 6, reflected by a rotating polygon mirror M,
The light is collected by the condensing lenses 6', 6'' and transmits information.The rotating polygon mirror M1 in the structural member 1 condensing lens 6.6',
This scanning optical device has a sealed structure to prevent dust from adhering to the 6". However, in order to measure the amount of laser light at a fixed location regardless of the stopping position of the rotating polygon mirror, it is necessary to use a laser light source. It is necessary to perform light intensity measurements between rotating polygon mirrors.

FIG. 2 is a cross section taken along the line A-A in FIG. 1, and here shows a conventional structure, in which a space 1a is formed between the light source device 2 of the structural member 1 and the condensing lens 6, and the space 1a has an external structure. An open gap 1b is provided. When measuring the amount of light, the light receiving element 8a is inserted into the space 1a through the gap 1b. In this conventional configuration, since the space 1a is exposed to the outside air through the gap 1b, the adhesion of dust within the space 1a cannot be avoided, which causes deterioration of imaging performance.

An object of the present invention is to overcome the above-mentioned conventional drawbacks, use a switchable movable reflection mirror to easily measure the amount of light while maintaining the entire laser optical device in a sealed structure, and maintain good imaging performance over a long period of time. The object of the present invention is to provide a laser optical device that can be obtained.

Next, the present invention will be described by way of examples with reference to the drawings. FIG. 8 is a sectional view of one embodiment of the present invention. In addition, the rotating polygon mirror M1 condenser lens 6.6', 6'' in FIG.
The arrangement of ' and the portions of the structural member 1 not shown in FIG. 8 are substantially the same between the present invention and the conventional structure. FIG. 8 shows a portion corresponding to the AA cross section in FIG. 1. In this diagram,
End of structural member 1 of the main body of the laser optical device (left side in the figure)
A light source device 2 is attached to the device. The light source device 2 has a frimeter lens system for converting the semiconductor laser light into a parallel light beam 2-1. A space 10 is formed in the structural member 1, one side of which communicates with the light source 1 through a hole 9, and the other side of which communicates with the condenser lens 6. The space 1C has a transparent window member 7, and the entire space is sealed by the structural member 1 and the transparent window member 7. space l
A mirror support member 3 rotatably supported by a rotating shaft 5 is disposed within C. 'A reflecting mirror 4 is mounted on one surface of the mirror support member 3, and is configured to reflect the parallel light beam 2-1 toward the transparent window member 7. Light receiving element 8
is detachably attached to the transparent window member 7. The mirror support member 8 can be placed in eight positions, A, C, and C as shown in FIG.

The position shown in A is a normal position, and the light beam 2-1 enters the lens 6 as it is.

At the mouth position, in order to measure the amount of light, the light beam 2-1 is guided out of the laser optical device by the reflecting mirror 4, transmitted through the window member 7, and the amount of light is measured by the light receiving element 8.

C is a position for sealing the hole 9 through which the light beam 2-1 passes, with the mirror support member 8. For example, when the semiconductor laser element in the light source device 2 breaks down, dust or the like is removed when replacing the light source device 2. It is possible to prevent the particles from entering the inside of the laser optical device.

FIG. 4 shows another embodiment of the invention, again with structural member 1
, space 1C light source device 2, condensing lens 6, transparent window member 7.
The e** child 8 and the hole 9 are all substantially the same as those described in FIG. In this embodiment, a reflective mirror pulley 10 having a reflective surface 10a is disposed inside the space 1c so as to be movable at right angles to the axial direction of the light source device 20'. The reflective mirror block 10 includes a reflective mirror block support l.
1 is provided to protrude from the structural member 1, and the reflecting mirror block 10 is moved by this.

The reflective mirror block 10 can be placed in the second and third positions,
At the second position, the light beam 2-1 enters the lens 6 as it is. Next, when the reflective mirror block 10 is moved to the position E using the reflective mirror block support base 11, the light flux passing hole 9 is sealed by the reflective mirror block 1o, and the light flux 2-1 is further turned back in the orthogonal direction and goes out through the transparent window member 7. The light receiving element 8 can measure the amount of light. ,゛As explained above, by providing a reflecting mirror inside the laser optical device so that it can be inserted into and taken out of the light beam, it is possible to switch the emission direction of the light beam while keeping the inside of the optical device in a sealed state, making it possible to easily and accurately measure the amount of light. At the same time, it is possible to completely prevent dust and the like from entering the apparatus, thereby avoiding deterioration of imaging performance.

[Brief explanation of the drawing]

Fig. 1 is a general explanatory sectional view of a laser optical device, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a sectional view of a conventional laser optical device.
The figure is a cross-sectional view of one embodiment of the present invention, and FIG. 4 is a cross-sectional view of another embodiment of the present invention. 1... Structural members of the main body of the laser optical device, 2...
... Light source device, 8 ... Reflection mirror support member, 4 ... Reflection mirror, 5 ... Rotation shaft,
6...Condenser lens, 7...Transparent window member, 10...Reflection mirror block, 11...
...Reflection mirror block support member. Figure 1 Figure 1 Figure 2

Claims (2)

[Claims] (1) In a laser scanning optical device equipped with a light source, a rotating polygon mirror, and a condensing lens, the light source, the rotating polygon mirror, and the condensing lens are arranged in a sealed structure, and the light source and the rotating polygon mirror are connected to each other. A laser scanning optical device characterized by being equipped with a movable reflective mirror that can be freely switched between. (2) The laser scanning optical device according to claim 1, further comprising a detachably provided light receiver for receiving the light reflected by the reflecting mirror.