Registers – Coded record sensors – Particular sensor structure
Reexamination Certificate
1998-05-28
2001-09-04
Frech, Karl D. (Department: 2876)
Registers
Coded record sensors
Particular sensor structure
C235S462470
Reexamination Certificate
active
06283373
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a light source module for a scanning apparatus such as a bar code reader, and to a scanning apparatus with the light source module.
2. Description of the Related Art
Recently, point-of-sale systems (POS systems) have become common in stores. In a POS system, a bar code reader reads a bar code provided on an article. According to the POS system, check-out work is carried out only by scanning a beam emitted from a bar code reader. Thus, the work of an operator (salesclerk) is reduced by using a bar code reader.
A bar code reader generally includes a light source for emitting a beam, an arrangement for generating a scanning beam by reflecting the beam from the light source, such as a rotating polygon mirror, a plurality of mirrors for reflecting the scanning beam and for dividing the scanning beam to provide a set of scanning lines outside of the bar code reader. The return beams reflected by a bar code on an article are condensed by a concave mirror or a condenser lens onto a light receiving device, such as a photodiode which generates an electrical signal corresponding to the return beams received by the light receiving device. These elements are sealingly contained within a housing to provide an optical unit.
Such an apparatus for reading a bar code is a kind of a scanner apparatus, similar to a scanner device in a laser printer or a copy machine, and is often referred to as a POS scanner or a bar code scanner. A laser diode is often used as a light source because of its compactness, low power consumption, and cost while a gas laser beam (for example, He—Ne laser beam) was originally used.
A laser diode has a problem that its life is shorter than a gas laser so that a bar code reader with a laser diode must be designed and used while considering replacement of the light source. Further, there is a problem that static electricity may damage a semiconductor laser.
In the prior art, a light source is provided by a VLD (Visible Laser Diode) module which includes a laser beam source, a lens and an aperture for shaping a beam.
When replacing a laser diode, the VLD module is replaced with the laser diode. In the prior art, the VLD module is contained within the housing of the optical unit. Thus, the housing of the optical unit must be opened to replace the VLD module. This work must be carried out in a clean room to prevent dust, which may harmfully effect to the optical characteristics of the scanner, from entering the optical unit. There is also a problem that the bar code reader to be mended cannot be used during the replacement of the VLD module.
SUMMARY OF THE INVENTION
The invention is directed to solve the above mentioned problems in the prior art and an the objective of the invention is to provide a light source module or a VLD module for a scanner apparatus, such as a bar code reader, or a scanning device in a laser printer or a copy machine, which is improved so that light source module can be replaced, without dust entering the optical unit of the scanner apparatus, wherever the scanner apparatus is used.
Another objective of the invention is to provide a light source module which is improved so that the effect of an static electricity on the laser diode is eliminated or reduced.
Another objective of the invention is to provide a scanner apparatus, such as a bar code reader, or a scanning device in a laser printer or a copy machine, which includes the light source module.
In order to achieve the objective, the invention provides a light source module which has a laser diode and a circuit board. The circuit board includes the laser diode, a driver circuit for the laser diode, and a connector for receiving a power supply for driving the laser diode from an electric power source. A lens and an aperture shapes the laser beam emitted by the laser diode. A housing made of electrically insulating material for contains the lens, the aperture and the circuit board except for a portion of the circuit board where the connector is mounted.
The light source module facilitates the replace thereof. The light source module further has an advantage that is removes or reduces the possibility of damage to the laser diode by static electricity since an operator can replace the light source module without touching the laser diode.
According to another feature of the invention, there is provided a scanning apparatus which comprises:
a light source module;
an optical unit including a housing in which means for receiving a beam from the light source module and reflecting the beam to provide the scanning beam, means for reflecting the scanning beam to provide a plurality of scanning lines outside of the housing, and means for receiving a return beam reflected by an article are sealingly contained; and
the housing including an arrangement for mounting the light source module outside of the housing and an aperture through which the beam can enter the housing.
According to another feature of the invention, a scanner for emitting a scanning beam is provided. The scanner comprises:
a light source for emitting a light beam;
an optical unit including an optical element for receiving the light beam form the light source and for producing a scanning beam, and a housing for enclosing the optical element, the housing including an aperture through which the light beam enters the housing; and
the light source being mounted to the exterior of the housing of the optical unit to direct the beam to the optical elements within the housing through the aperture.
According to an embodiment of the invention, the optical unit preferably includes a scanning mirror for producing a scanning beam, a plurality of mirrors for reflecting the scanning beam and for dividing the scanning beam into first and second sets of scanning beam segments, an optical receiver element for receiving the return beam reflected by a bar code to produce an electrical signal responsive to the return beam, and a housing for enclosing the scanning mirror, the plurality of mirrors, and the optical receiver element, the housing including an aperture, and first and second openings through which the first and second sets of scanning beam segments propagate outside of the housing to provide fist and second sets of scanning lines outside of the scanner. The light source is secured to the exterior of the housing to direct the light beam to the scanning mirror through the aperture provided in the housing.
According to another feature of the invention, a bar code scanner for reading a bar code is provided. The bar code scanner comprises:
a light source for emitting a light beam;
an optical unit including a scanning mirror for producing a scanning beam, a plurality of mirrors for reflecting the scanning beam and for dividing the scanning beam into first and second sets of scanning beam segments, an optical receiver element for receiving the return beam reflected by a bar code to produce an electrical signal responsive to the return beam, and a housing for enclosing the scanning mirror, the plurality of mirrors, and the optical receiver element, the housing
1
including an aperture, and first and second openings through which the first and second sets of scanning beam segments propagate outside of the housing to provide fist and second sets of scanning lines outside of the scanner. The light source is secured to the exterior of the housing to direct the light beam to the scanning mirror through the aperture provided in the housing.
According to yet another feature of the invention, a bar code scanner for reading a bar code is provided. The bar code scanner comprises:
a light source for emitting a light beam;
an optical unit including a scanning mirror for producing a scanning beam, a plurality of mirrors for reflecting the scanning beam and for dividing the scanning beam into a set of scanning beam segments, an optical receiver element for receiving the return beam reflected by a bar code to produce an electrical signal responsive to the return beam, and a housing for enclosing the
Ichikawa Toshiyuki
Ohkawa Masanori
Watanuki Hiroshi
Yamazaki Kozo
Frech Karl D.
Fujitsu Limited
Staas & Halsey , LLP
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