JPH05289010A - Scan start signal detector for deflecting scanner - Google Patents

Abstract

PURPOSE:To provide a scan start signal detector for a deflecting scanner manufactured without requiring work to assemble a lens with a holder. CONSTITUTION:The scan start signal detector A1 for the deflecting scanner is comprised of a sensor 1 which detects a scan start signal and the holder 2, and the holder 2 is provided with a sensor holding part 3 which holds the sensor 1, a lens part 4, and a slit part 5, and they are provided integrally with a main body 2a, and also, they are made of transparent material with the main body 2a. Assembling is performed without requiring the work to mount the lens on the holder, and it is enough to mount the sensor 1 on the holder. The slit part 5 consists of a pair of transparent columnar members 6, 7, and incident light to them is internally reflected on their oblique surfaces 6a, 7a, and is diffused and absorbed on each of side surfaces 6b, 7b made into coarse surfaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning start signal detector used in a deflection scanning device of a laser beam printer or a laser facsimile.

[0002]

2. Description of the Related Art As shown in FIG. 5, a deflection scanning device for a laser beam printer or a laser facsimile includes a laser oscillator 111, a collimator lens 112, a cylindrical lens 113, a rotary polygon mirror 114, a spherical lens 115, a toric lens 116, and a scanning device. Start signal generating mirror 11
7 and includes a scanning start signal detector A _0, the laser beam L ₁ emitted from the laser oscillator 111 is collimated by the collimator lens 112, it is deflected and scanned by the rotary polygon mirror 114 via a cylindrical lens 113. The laser beam L ₂ deflected and scanned by the rotary polygon mirror 114 passes through a spherical lens 115 and then a toric lens 116 to form an image on the surface of a photosensitive drum (not shown). A part L _{p of the} deflected and scanned laser beam L ₂
Is reflected by the mirror 117 for scanning start signal generated is introduced to the scanning start signal detector A _0, it is detected as a trigger signal for image rendering and position of the surface of the photosensitive drum by the scanning start signal detector A ₀ It

The scanning start signal detector A ₀ is arranged apart from the scanning surface of the laser beam L ₂ in a direction perpendicular to the paper surface of FIG. 5 so as not to interfere with the scanning surface. As shown in FIG. 4, the conventional scanning start signal detector A ₀ has a mirror 11
The slit means 105, the lens 104, the sensor 101, and the holder 102 supporting these are arranged in series in the optical path of the laser beam L _p reflected by the laser beam L 7.

The slit means 105 is composed of a pair of columnar members 106 and 107 which are separated from each other, and both of them are integrally provided with the holder 102 at one end thereof. Further, the lens 104 is assembled at a predetermined position of the holder 102, and the sensor 101 is attached to the holder 102.
It is supported by the sensor holding portion 103 that is integrally provided in the.

[0005]

However, according to the above-mentioned conventional technique, the lens and the holder are separate from each other, and due to an assembling error when assembling the lens into the holder, the sensor also attached to the holder. There is a risk of relative displacement between the lens and the lens, and the surface of the lens may be contaminated or damaged during the assembling work. Further, since the number of parts to be manufactured and the number of assembling steps are large, the manufacturing cost cannot be reduced.

The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and does not require the work of assembling the lens to the holder in the manufacturing process, and therefore the number of manufacturing parts and the number of manufacturing processes are small. It is an object of the present invention to provide a scanning start signal detector of a deflection scanning device which does not have a risk of soiling or damaging the lens by the assembling work.

[0007]

In order to achieve the above object, the scanning start signal detector of the deflection scanning device of the present invention comprises:
A sensor for receiving a part of the illumination light scanned by the deflection scanning means, a lens and a slit means arranged along the optical path of the illumination light incident on the sensor, and supporting the sensor, the lens and the slit means. A scanning start signal detector of a deflection scanning device comprising a holder, wherein the holder is provided integrally with the lens, and is made of the same transparent material as the lens.

Further, the slit means is composed of a pair of columnar members which are integrally formed with the holder and are made of a transparent material and are spaced apart from each other, and each columnar member has an inclined surface for totally reflecting the illumination light incident thereon. The side surface of each columnar member on the side from which internal reflection light is emitted by the inclined surface may be roughened.

[0009]

A part of the illumination light scanned by the deflection scanning means is introduced into the scanning start signal detector as a scanning start signal, and enters the sensor through the lens and the slit means. Since the holder for holding these is integrally provided with the lens by the same transparent material as that of the lens, it is not necessary to assemble the lens into the holder when manufacturing the scanning start signal detector.

Further, when the slit means is composed of a pair of columnar members made of a transparent material and provided integrally with the holder, the illumination light incident on each columnar member is totally reflected by the inclined surface, and The internal reflection light from the inclined surface can be shielded by diverging and absorbing it by the roughened side surface, and it is not necessary to add a light shielding means such as masking.

[0011]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing a first embodiment,
The scanning start signal detector A ₁ of the deflection scanning device of this embodiment comprises a sensor 1 and a holder 2 supporting the same. The holder 2 comprises a body 2a integrally made of a transparent resin material such as acrylic or polycarbonate, a sensor holding portion 3, a lens portion 4 which is a lens, and a slit portion 5 which is a slit means. As shown in FIG. 2, the lens portion 4 and the slit portion 5 are integrally formed with the main body 2a at one end thereof. The sensor 1 is held by the sensor holding unit 3.

The slit portion 5 is a pair of columnar members 6 and 7.
And a slit S for passing the laser beam L _p is formed between them. Each of the columnar members 6 and 7 has a substantially triangular cross section, and the inclined surfaces 6a and 7a are arranged on the downstream side of the slit S along the optical path of the laser beam L _p . The inclined surfaces 6a, 7a are light L _e entering each columnar members 6 and 7 toward the sensor 1 is arranged at an angle to totally reflect also the inclined surfaces 6a, internally reflected by 7a The side surfaces 6b, 7b on the side that emits light are roughened.

The laser beam L _p is a scanning start signal detector A ₁ by a mirror (not shown) of a part of the laser beam which is illumination light deflected and scanned by a rotary polygon mirror (not shown) which is deflection scanning means. It is reflected to the sensor 1, passes through the slit S, is introduced into the sensor 1 through the lens portion 4, and is detected as a scanning start signal. On the other hand, without passing through the slits S, the light L _e incident on the columnar members 6 and 7 toward the sensor 1, each of the inclined surfaces 6
The light is totally reflected by a and 7a, and then diffused and absorbed when emitted from the roughened side surfaces 6b and 7b. That is, the inclined surfaces 6a, 7a and the side surfaces 6b, 7b of each of the columnar members 6, 7 function as a light blocking means for blocking light other than the laser beam L _p incident on the sensor 1 through the slit S.

According to this embodiment, since the lens portion is integrally provided on the holder made of a transparent material, the step of assembling the lens with the holder can be omitted when manufacturing the scanning start signal detector. it can. Further, a relative positional deviation does not occur between the lens and the sensor due to a lens mounting error. Further, even if the slit part is made of a transparent material integrally with the holder, the incident light is internally reflected by the inclined surface of each columnar member, and then is diverged and absorbed by the roughened side surface. It is not necessary to add light-shielding means such as masking.

FIG. 3 is a plan view showing a second embodiment,
The scanning start signal detector A ₂ of the deflection scanning device of this embodiment is
A slit portion 25, which is slit means, is arranged between the sensor holding portion 23 of the holder 22 and the lens portion 24 which is a lens. The main body 22a of the holder 22, the sensor holding portion 23, the lens portion 24 and the slit portion 25 are integrally provided, and are entirely made of the same transparent material.

Since the other points are the same as those of the first embodiment, the description thereof will be omitted.

[0018]

Since the present invention is configured as described above, it has the following effects.

Since the lens is formed integrally with the holder, it is not necessary to attach the lens to the holder in the manufacturing process. Therefore, the number of parts to be manufactured and the number of manufacturing steps are small, and there is no possibility that the lens is contaminated or damaged by the assembling work.

Further, the slit means is provided integrally with the holder together with the lens, and even if the slit means is made of the same transparent material as the lens, by providing a light shielding function by internal reflection, a light shielding means such as masking is added. It is possible to avoid an increase in the number of manufacturing processes due to the process.

As a result, it is possible to produce a scanning start signal detector of a deflection scanning device with good performance at low cost.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view showing a first embodiment.

2 is a cross-sectional view of the device of FIG.

FIG. 3 is a partially cutaway plan view showing a second embodiment.

FIG. 4 is a partially cutaway plan view showing a conventional example.

FIG. 5 is an explanatory diagram illustrating a deflection scanning device.

[Explanation of symbols]

A ₁ , A ₂ Scanning start signal detector of deflection scanning device L _p Laser beam 1 Sensor 2,22 Holder 2a, 22a Main body 3,23 Sensor holding part 4,24 Lens part 5,25 Slit part 6,7 Columnar member 6a , 7a Inclined surface 6b, 7b Side surface

Claims (2)

[Claims] 1. A sensor for receiving a part of the illumination light scanned by the deflection scanning means, a lens and a slit means arranged along an optical path of the illumination light incident on the sensor, the sensor, the lens, and A scanning start signal detector of a deflection scanning device comprising a holder that supports the slit means, wherein the holder is provided integrally with the lens and is made of the same transparent material as the lens. A scanning start signal detector for a deflection scanning device. 2. The slit means is composed of a pair of columnar members made of a transparent material which are provided integrally with the holder and are spaced apart from each other, and each columnar member has an inclined surface for totally reflecting the illumination light incident thereon. The scanning start signal detector of the deflection scanning device according to claim 1, wherein a side surface of each columnar member on the side from which the internal reflection light is emitted by the inclined surface is roughened.