Optical apparatus with replacement semiconductor laser

An optical apparatus including a laser light source unit and an apparatus main body is disclosed. The laser light source unit has a barrel for holding a lens and a unit side connector for connecting a semiconductor laser to an external circuit. The apparatus main body has an insertion hole and a main body side connector. The unit side connector is intended to be connected to the main body side connector when the barrel is inserted in the insertion hole.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an optical apparatus such as a laser 
scanner having a semiconductor laser as a light source. 
2. Description of the Related Art 
Laser scanners have been used to read out bar-codes, for example, in POS 
systems in super-markets. As a light source of the optical apparatus of 
this type, a semiconductor laser (laser diode) has been generally used for 
reducing the size of the apparatus and realizing the power saving of a 
light source. However, because of the short service life of a 
semiconductor laser relative to the operating time of the optical 
apparatus of this type, there has been demands toward the easy replacement 
of the light source. 
Although a laser scanner has been known as a commercial apparatus having a 
semiconductor laser as a light source, there has not yet been proposed a 
structure intended to simplify the replacement of a semiconductor laser. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide an optical apparatus 
capable of easily replacing a semiconductor laser. 
According to the present invention, there is provided an optical apparatus 
having a semiconductor laser as a light source, including: a laser light 
source unit having the semiconductor laser for converting a light emitted 
from the semiconductor laser into a specified light beam and outputting 
the specified light beam; and an apparatus main body on which the laser 
light source unit is removably mounted. The above laser light source unit 
further has a barrel for guiding the light beam, and a unit side connector 
for connecting the semiconductor laser to an external circuit. The above 
apparatus main body has an insertion hole into which the barrel is closely 
inserted, and a main body side connector to which the unit side connector 
is connected. With this arrangement, the unit side connector is intended 
to be connected to the main body side connector when the barrel is 
inserted in the insertion hole. 
An optical apparatus of the present invention is so constructed that a 
laser light source unit is removably mounted onto an apparatus main body 
for easily replacing a semiconductor laser. In the replacement of a 
semiconductor laser, the barrel of the laser light source unit is closely 
inserted in an insertion hole of the apparatus main body, and 
simultaneously a unit side connector is connected to a main body 
connector. The rotational position of the barrel is thus determinable, 
which eliminates the need for the adjustment of an optical axis. 
The above and other objects, features and advantages of the present 
invention and the manner of realizing them will become more apparent, and 
the invention itself will best be understood from a study of the following 
description and appended claims with reference to the attached drawings 
showing some preferred embodiments of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Hereinafter, embodiments of the present invention will be described in 
detail with reference to the drawings. 
FIG. 1 is a perspective view of a bar code scanner embodying the present 
invention. The scanner has a laser light source unit 2 containing a 
semiconductor laser, and an apparatus main body 4 on which the laser light 
source unit 2 is to be removably mounted. A scanning unit (not shown) 
scans a laser light through a platen glass 6 provided on the upper portion 
of the apparatus main body 4 for reading out a bar code label attached on 
an article of commerce or the like (not shown). The laser light source 
unit 2 is mounted on a unit mounting portion 8 of the apparatus main body 
4, and which is usable in the state that an openable cover 10 provided on 
the apparatus main body 4 is closed. 
FIG. 2 is a sectional view of the unit mounting portion shown in FIG. 1. 
The laser light source unit 2 has a semiconductor laser 12, and a lens 14 
for converting a light emitted from the semiconductor laser 12 into a 
specified light beam. The lens 14 is held in a lens barrel 16 formed 
substantially in a cylindrical shape (for example, taper-off shape in 
cross-section). The semiconductor laser 12 is contained in a unit case 20 
while being mounted on a circuit board 18. The unit case 20 is joined to 
the lens barrel 16 in such a manner as to hold a predetermined positional 
relationship between the semiconductor laser 12 and the lens 14, thus 
forming the laser light source unit 2. A unit side connector 22 for 
connecting the semiconductor laser 12 to an external circuit is mounted on 
the circuit board 18. In addition, electronic parts forming a circuit for 
driving the semiconductor laser 12 are mounted on the circuit board 18. 
The unit mounting portion 8 of the apparatus main body 4 is provided with 
an insertion hole 26 into which the lens barrel 16 is closely inserted, 
and a main body side connector 24 to which the unit side connector 22 is 
connected. 
In the apparatus of this embodiment, the parts are arranged such that the 
unit side connector 22 is connected to the main body side connector 24 
when the lens barrel 16 of the laser light source unit is inserted into 
the insertion hole 26 of the apparatus main body. The insertion hole 26 
has the shape corresponding to that of the lens barrel 16 such that the 
barrel 16 is closely inserted into the insertion hole 26. By closely 
inserting the barrel 16 into the insertion hole 26, the positioning of the 
laser beam output from the laser light source unit 2 relative to the 
apparatus main body 4 is determinable. Moreover, since the lens barrel 16 
is usually located at the same rotational position, the direction of the 
laser beam is also determinable. Additionally, the semiconductor laser 12 
is positioned substantially along the center axis of the lens barrel 16, 
so that the laser beam can be output in the direction parallel to this 
center axis. Accordingly, only by positively mounting the laser light 
source unit 2 on the mounting portion 8 of the apparatus main body 4, the 
semiconductor laser can be replaced without any additional complicated 
work such as the adjustment of the optical axis. In this embodiment, the 
parts are arranged such that the lens barrel 16 is inserted in the 
insertion hole 26 when the unit side connector 22 is connected to the main 
body side connector 24, and accordingly, there is no fear that a laser 
beam is leaked to the exterior in the state that the laser light source 
unit 2 is not mounted on the apparatus main body 4. 
In the replacement of the laser light source unit, for preventing the 
breakage of an laser element due to electrostatic charge, it is desirable 
to provide a short-circuiting pin on the laser light source unit. Another 
embodiment improved in this regard will be described below. 
FIG. 3 is a perspective view of a laser light source unit having a 
short-circuiting pin. In this embodiment, a lens barrel 16 and a unit side 
connector 22 are provided on the same side of the unit case 20, and on the 
other side of the unit case 20, a short-circuiting pin 28 for 
short-circuiting a signal line connected to the semiconductor laser is 
provided. Reference numeral 30 designates a short-circuiting pin cover 
removably mounted on the short-circuiting pin 28. The signal line of the 
semiconductor laser is short-circuited when the short-circuiting pin cover 
30 is mounted on the short-circuiting pin 28. 
FIG. 4 is a sectional view showing the construction of the short-circuiting 
pin cover 30. The short-circuiting pin cover 30 has a cover main body 30A 
having such a shape as to be removably mounted to the short-circuiting pin 
28, and a conductive metal fixture 30B having one end being press-fitted 
in the cover main body 30A and the other end being elastically deformable. 
When the short-circuiting pin cover 30 is mounted on the short-circuiting 
pin 28, the conductive metal fixture 30B abuts the short-circuiting pin 28 
by its elastic force. This achieves both the short-circuiting of the 
signal line of the semiconductor laser and the holding of the 
short-circuit pin cover 30. In this embodiment, during mounting the laser 
light source unit on the apparatus main body 4 shown in FIG. 1, the 
short-circuiting pin cover 30 remains mounted to the short-circuiting pin 
28, so that it becomes possible to prevent the breakage of the 
semiconductor laser due to the electrostatic charge. 
The short-circuiting pin cover 30 is required to be necessarily removed 
after the laser light source unit is mounted on the apparatus main body 4. 
FIGS. 5A, 5B and 5C show a structure allowing an operator to easily check 
for the removable of the short-circuiting pin cover 30. As shown in FIG. 
5A, directly under the short-circuiting pin 28 on the inner side of the 
cover 10, a projection 10A is provided at the position corresponding to 
that of the leading edge portion of the short-circuiting pin cover 30. In 
the case where the short-circuiting pin cover 30 remains mounted on the 
laser light source unit 2, as shown in FIG. 5B, the projection 10A abuts 
the leading edge portion of the short-circuiting pin cover 30, which does 
not allow the cover 10 to be closed. On the contrary, in the case where 
the short-circuiting pin cover 30 is removed from the laser light source 
unit 2, as shown in FIG. 5C, the cover 10 can be closed. Thus, by checking 
whether or not the cover 10 can be perfectly closed, it can be judged 
whether or not the short-circuiting pin cover 30 is certainly removed. 
FIGS. 6A and 6B are partial sectional views of a laser light source unit 
according to a further embodiment of the present invention; and FIG. 7 is 
a perspective view of FIGS. 6A and 6B. In this embodiment, 
short-circuiting of the short-circuiting pin and the release thereof are 
automatically performed. In a laser light source unit 2 of this 
embodiment, as shown in FIG. 6A, a unit case 20 contains a rockable 
short-circuiting metal fixture 32 for short-circuiting the 
short-circuiting pin 28, and a spring 34 for biasing the short-circuiting 
metal fixture 32 such that the first end of the short-circuiting metal 
fixture 32 is contacted with the short-circuiting pin 28. The second end 
of the short-circuiting metal fixture 32 is located at the position 
corresponding to that of an opening 20A formed in the unit case 20. In 
mounting the laser light source unit 2, the first end of the 
short-circuiting metal fixture 32 is contacted with the short-circuiting 
pin 28 by the biasing force of the spring 34, so that the semiconductor 
laser is made in the short-circuit state, thus preventing the damage of 
the semiconductor element due to electrostatic charge. 
When the cover 10 is closed relative to the apparatus main body after the 
mounting of the laser light source unit, a projection 10B formed on the 
inner side of the cover 10 abuts the second end of the short-circuiting 
metal fixture 32 through the opening 20A of the unit case 20. Thus, as 
shown in FIG. 6B, the first end of the short-circuiting metal fixture 32 
is released from the short-circuiting pin 28, so that the semiconductor 
laser is made in the operable state. In this embodiment, the removable 
mounting of the short-circuiting pin cover in the previous embodiment is 
eliminated, and accordingly, the replacement of the laser light source 
unit can be further simplified. 
The present invention, as described above, has an effect to provide an 
optical apparatus capable of easily replacing a semiconductor laser. 
While specific embodiments of the present invention have been described in 
the foregoing description, the present invention is not limited to details 
of the embodiments. The spirit and scope of the present invention is 
defined in the appended claims, and all alterations and modifications 
which belong to the scope of equivalency of the claims shall be included 
in the scope of the present invention.