JPH06242359A - Method for fixing lens of laser unit - Google Patents

Abstract

PURPOSE:To restrain the deviation of an optical axis in a light emitting part and an adjusting part minimum in the case of focusing a laser beam. CONSTITUTION:This unit is constituted of a laser diode 1, a lens holder 2 and a case 3 housing them, and performed with adjustment by causing the lens holder 2 to slide by means of a sucking tool 5. The unit uses a method for fixing a lens with adhesive from an adhesion hole 4 in a state where it is sucked by air in order to restrain the deviation of the optical axis in the light emitting part and the adjusting part minimum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a laser unit,
In particular, it relates to the assembly of a laser scanning unit of an electrophotographic printer.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, focus adjustment of a laser scan unit of this type is made up of a laser diode 1 of a laser emitting section, a lens holder 2 of a focus adjusting section, and a case 3 for housing them. A screw 4 is provided to fix the lens holder 2 at a focused position.

Next, the adjusting method will be described. First, the laser diode 1 is caused to emit light and the light is passed through the lens holder 2. Next, the lens holder 2 is sucked by the suction tool 5, and the position is determined by sliding the inside of the case 3 to an appropriate position in focus. When the position is decided, the suction tool 5 is released and fixed with the screw 6.

[0004]

With this conventional adjustment and fixing method, when fixing the lens holder 2 after the focus adjustment, the lens holder 2 pushed by the screw 6 is pushed to one side and cannot be solved in terms of component accuracy. The backlash dimension a occurred. The dimension a is harmful as a deviation between the optical axis of the laser diode 1 and the optical axis of the lens holder 2 and is a problem that must be solved.

[0005]

In the lens fixing method of the present invention, the fixing screw for holding the lens holder is removed, and an adhesive method is used instead, and the lens holder is floated without applying force while adsorbing air. Fix in the state.

[0006]

The present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention. In the figure, the light emitted by the laser diode 1 is
An appropriate beam diameter can be obtained by slidingly adjusting the lens holder 2. The slide adjustment is performed by the suction tool 5. Next, as a method of fixing the lens holder 2 to the case 3, there is an adhesive hole 4, and the lens holder 2 is quickly fixed with an adhesive. Next, the suction tool 5 is released and the construction is completed.

At this time, it is desirable that no gas is generated in order to protect the lens, which is important for the characteristics of the adhesive.

[0009]

As described above, according to the present invention, the method of fixing the lens holder is changed from screw fixing to adhesive fixing, so that the lens holder can be fixed at a position very close to the actual adjustment position where air is adsorbed. . As a result, the deviation of the optical axis from the laser emitting section can be suppressed to a very small level.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a conventional example.

[Explanation of symbols]

 1 Laser diode 2 Lens holder 3 Case 4 Bonding hole 5 Suction tool 6 Screw

Claims (2)

[Claims] 1. A laser unit including a laser emitting unit for emitting laser light, a lens holder for adjusting a focus and a case for housing them, for adjusting and fixing the optical axes of the laser emitting unit and the lens holder. In the lens fixing method, the laser unit is characterized in that an adhesive is poured between the lens holder and the case in a state where the lens holder is sucked by a suction tool and held at a predetermined position in the lens holder. Lens fixing method. 2. The lens fixing method for a laser unit according to claim 1, wherein the adhesive is injected through a hole provided in a side wall of the case.