JP2002296530A - Optical fiber optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the light utilization efficiency of an optical fiber optical device performing optical recording by scanning photosensitive material with a purple semiconductor laser beam by using an optical fiber. SOLUTION: A hole (13) discharging gas inside an LD module between a lens (2) and a ferrule folder (6) to the outside is provided on the LD module.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber optical device such as an electrophotographic device and an optical disk device for performing optical recording by scanning a violet semiconductor laser beam on a photosensitive material using an optical fiber.

[0002]

2. Description of the Related Art An optical apparatus for performing optical recording by scanning a photosensitive material with a laser beam using an optical fiber is known, for example, from Japanese Patent Application Laid-Open No. 5-93878.

[0003]

In an optical device of this type, it is important that light emitted from a semiconductor laser is incident on an optical fiber with high light use efficiency and that the light use efficiency is stabilized. In an LD module using a violet semiconductor laser that emits laser light having a wavelength of 450 nm or less, a volatile component generated from an adhesive used when assembling the LD module accumulates inside the LD module. In addition, it may adhere to the glass surface on the optical axis and reduce the coupling efficiency of the violet laser light to the optical fiber. This does not occur with a semiconductor laser that emits red light, but is considered to have occurred with a semiconductor laser that emits purple light because the photochemical reaction became significant.

[0004] An object of the present invention is to prevent the volatile components released from the adhesive from adhering to the end face of the optical fiber and the glass surface on the optical axis, thereby lowering the coupling efficiency to the optical fiber. The purpose is to stabilize the light use efficiency of the optical device.

[0005]

An object of the present invention is to provide a violet semiconductor laser that generates violet laser light in an optical device that scans a photosensitive material by modulating and scanning violet semiconductor laser light emitted from an optical fiber. Having a lens for condensing laser light emitted from a violet semiconductor laser
In a LD module having a folder, a ferrule folder supporting a ferrule fixed to an LDM folder, and an optical fiber provided with the ferrule and the ferrule folder at a distal end portion, inside the LD module between the lens and the ferrule folder. This is achieved by providing a hole in the LD module for discharging the gas outside.

[0006]

FIG. 1 is a sectional side view showing an embodiment of an optical fiber unit applied to an optical device according to the present invention. The optical fiber unit includes a violet semiconductor laser 1, a lens 2, a flat glass 5, an optical fiber 8, an LDM folder 3, an LDM folder 4, a ferrule 7, and a ferrule folder 6. In this example, the case where the LDM folder is divided into the LDM folder 3 and the LDM folder 4 is illustrated, but the LDM folder does not necessarily have to be divided.

The LDM folders 3 and 4 and the ferrule folder 6 are made of stainless steel or a material having a low coefficient of thermal expansion,
For example, it is formed of Invar or Kovar. The purple semiconductor laser 1 is fixed to the LDM folder 3 by laser welding using a pulsed YAG laser. The lens 2 for condensing the laser light on the optical fiber is adhered to the LDM folder 3 with epoxy resin. In order to facilitate handling of the optical fiber, the tip 9 of the optical fiber is fitted into the ferrule 7 and the ferrule 7 is fitted into the ferrule folder 6 and bonded with epoxy resin. The ferrule folder 6 is provided for the purpose of increasing the bonding area so that sufficient mechanical strength is maintained when the ferrule folder 6 is bonded to the flat glass 5. Then, the optical fiber end face 9,
The ferrule 7 and the ferrule folder 6 are polished so that they are flush with each other. The flat glass 5 having a hole through which a laser beam penetrates is provided on the polished surface of the ferrule folder 6 by UV.
Adhering via resin 10 and U
By irradiating V light, the UV resin 10 is cured, and the flat glass 5 is fixed to the polished surface of the ferrule folder 6.

FIG. 1 shows an LDM folder 3 and an LDM folder 4 provided with holes for discharging gas inside the LD module to the outside.
As shown in FIG. 5, the LDM folder 4 is slidable in the direction of the optical axis of the laser light because it is in contact with a plane parallel to the optical axis of the laser light. When attaching the LDM folder 4 to the LDM folder 3, the flat glass 5 to which the ferrule folder 6 is adhered is brought into close contact with a surface of the LDM folder 4 perpendicular to the optical axis of the laser light, and the laser emitted from the violet semiconductor laser 1. LDM so that the focal point of the light coincides with the polished surface 9 of the optical fiber.
Slide folder 4 to adjust. After the adjustment, the LDM folder 4 is fixed to the LDM folder 3 by laser welding, or an epoxy resin is filled between the LDM folder 3 and the LDM folder 4, and the epoxy resin is cured to fix the LDM folder 4.

The space between the flat glass 5 adhered to the ferrule folder 6 and the LDM folder 4 is filled with UV resin 11 outside the outer diameter of the ferrule folder 6, and the position of the optical fiber 8 is adjusted. Since the position of the focal point of the laser beam coincides with the optical fiber polished surface 9 when the flat glass 5 adhered to the ferrule folder 6 and the LDM folder 4 are brought into close contact with each other, and the tolerance (permissible error of the positional deviation) is large. The position of the laser light in the optical axis direction can be adjusted by bringing the flat glass 5 adhered to the ferrule folder 6 and the LD cap close to each other. Position adjustment in the direction perpendicular to the optical axis of the laser light is performed by a fine adjustment jig to which a ferrule folder is attached so that the focal position of the laser light matches the light propagation portion of the optical fiber.

[0010] Further, UV light is irradiated from the direction of the surface of the flat glass to which the ferrule folder is adhered to cure the UV resin. The UV resin is non-heat-cured and is cured by short-time light for a few seconds, so that the thermal expansion of the jigs and folders hardly affects the temperature change during curing. Also,
In the present invention, since the surfaces are bonded to each other, the volume of the UV resin is small, and the resin shrinks little during curing. Therefore, when the optical fiber 8 is fixed according to the present invention, the optical fiber 8 hardly displaces during curing. In this embodiment, quartz glass was used for the flat glass, and acrylic or epoxy resin was used as the UV resin.

FIG. 2 shows the optical fiber unit 5
FIG. 1 is a schematic configuration diagram of an optical system of an electrophotographic apparatus provided with the present invention. By providing the output ends of the respective optical fibers in an array to form the optical fiber ray 17, a multiple beam generator capable of emitting five laser beams from the optical fiber ray is formed. The five laser beams are collimated by a collimator lens 17 and then deflected by a polygon mirror.
Scan up.

FIG. 3 shows a detailed configuration of the optical fiber lay 16. The optical fiber 8 includes a clat 23 and a core 22 mainly composed of SiO ₂ , and a jacket made of nylon resin or the like for protecting them. The diameter of the tip of the clat 23 excluding the outer jacket is a highly accurate circular shape of about 125 μm. On the other hand, the diameter of the core 22 through which light is guided is about 4 μm in the case of a single mode fiber, and the core 22 is precisely arranged at the center of the clat 23.

Accordingly, a plurality of optical fibers excluding the jacket are sandwiched between the flat plates 21 from above and below as shown in FIG. 3, and the clats 23 are pressed from both sides of the pressing plate 24 so as to be in close contact with each other. Thereafter, when the optical fiber lay 16 is fixed with an adhesive and the end faces are polished, core rows arranged in a straight line and arranged at an equal pitch, that is, an array of multiple beams are obtained.

Since the core arrangement pitch is 125 μm while the core diameter is 4 μm, the spot interval p ₀ is 125 times the spot diameter p on the optical recording material. In order to solve this problem, as shown in FIG. 4, the multiple beam arrangement direction θ is inclined so that the light spot diameter and the scanning line pitch p are substantially equal. For this purpose, the optical fiber lay section 16 is inclined.

As described above, in an optical device that modulates and scans a violet semiconductor laser beam emitted from an optical fiber and scans a photosensitive material, a violet semiconductor laser that generates a violet laser beam and a laser beam emitted from the violet semiconductor laser. An LDM folder having a lens for condensing the laser light, a ferrule folder supporting a ferrule fixed to the LDM folder, and an LD module having an optical fiber provided with the ferrule and the ferrule folder at a tip end thereof. Various adhesives are used for assembly, and gas volatilized from the adhesive is generated inside the LD module.
Such a gas is deposited on the light condensing portion on the end face of the optical fiber by the photochemical reaction of the violet laser light, adheres as a foreign substance, and lowers the efficiency of light coupling to the optical fiber. In order to prevent such a phenomenon, by providing a hole in the LD module between the lens and the ferrule folder to allow the gas inside the LD module to be discharged to the outside, it was used when assembling the LD module. Prevents volatile components released from the adhesive from adhering to the end face of the optical fiber and the glass surface on the optical axis, which lowers the coupling efficiency to the optical fiber and stabilizes the light use efficiency of the optical device. Was able to be transformed. The present invention is not limited to the electrophotographic apparatus, but can be applied to all optical apparatuses such as an optical disk apparatus that scans a photosensitive material with a laser beam using an optical fiber and performs optical recording.

[0016]

According to the present invention, a decrease in coupling efficiency to an optical fiber due to a volatile component released from an adhesive adhering to an end surface of an optical fiber and a glass surface on an optical axis is suppressed. An optical fiber optical device with stable usage efficiency can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an optical fiber unit of the present invention.

FIG. 2 is a schematic configuration diagram of an optical fiber optical device of the present invention.

FIG. 3 is a configuration diagram showing an optical fiber ray of the present invention.

FIG. 4 is an explanatory diagram showing a multiple beam scanning method in the optical fiber optical device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Purple semiconductor laser, 2 ... Lens, 3, 4 ... LDM folder, 5 ... Quartz glass, 6 ... Ferrule folder, 7 ... Ferrule, 8 ... Optical fiber, 10, 11 ... UV resin, 13
... Hole, 15 ... LD module, 16 ... Optical fiber ray, 1
7 ... Collimator lens, 18 ... Polygon mirror, 19 ... F
θ lens, 20 photosensitive drum, 22 core, 23 clat.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C362 AA03 AA42 AA43 AA45 BA25 2H037 AA04 BA03 DA03 DA06 2H045 AA01 CB41 DA02 DA41 5F073 AB27 AB28 BA06 EA07 EA15 FA06

Claims (2)

[Claims] 1. An optical device for scanning a photosensitive material by modulating and scanning a violet semiconductor laser beam emitted from an optical fiber, wherein the violet semiconductor laser generates a violet laser beam, and a laser beam emitted from the violet semiconductor laser. An LDM folder having a lens that collects light, a ferrule folder that supports a ferrule fixed to the LDM folder, and an LD module having an optical fiber provided at the tip of the ferrule and the ferrule folder, wherein the lens and An optical fiber optical device, wherein a hole for discharging gas inside the LD module to the outside between the ferrule folders is provided in the LD module. 2. An optical fiber optical device according to claim 1, wherein said hole is closed after gas generated from inside the LD module between said lens and said ferrule folder is exhausted to the outside.