|Publication number||USRE41876 E1|
|Application number||US 11/274,717|
|Publication date||Oct 26, 2010|
|Filing date||Nov 14, 2005|
|Priority date||Jun 21, 2000|
|Also published as||US6646769|
|Publication number||11274717, 274717, US RE41876 E1, US RE41876E1, US-E1-RE41876, USRE41876 E1, USRE41876E1|
|Original Assignee||Po-Hua Fang|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (15), Referenced by (2), Classifications (19), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
(1) Field of the Invention
The invention relates to a light source mechanism for an imaging apparatus, and more particularly to a combination which integrate a point light source with a light shield for producing a line light source with enhanced homogeneous illumination.
(2) Description of the Prior Art
An imaging apparatus or a scanner is one of popular computer peripherals. In an imaging apparatus, an internal light source is used to generate an image from a document rested upon a document plate. The image is then forwarded through a plurality of lenses and experiencing a proper travel path to reach a CCD for being transformed into digital signals. The digital signals are then sent to a computer for further image processing.
Referring now to FIG. 1A and
Nevertheless, the conventional light source mechanism 1 as discussed generally has several disadvantages as follows.
To resolve the aforesaid disadvantages of the conventional imaging apparatus using the fluorescent tube as the light source, additional effort in the industry to develop an improved light source mechanism is definitely necessary for producing an imaging apparatus with low cost, long life term, quality performance and wide-ranged application.
Accordingly, it is a primary object of the present invention to provide a light source mechanism for an imaging mechanism, in which a point light source is applied to provide improved imaging quality and advantages of low cost, stable illumination, long life term and a wider application range.
The light source mechanism for an imaging apparatus in accordance with the present invention includes at least a point light source and a light shield. The light source of the present invention for the imaging apparatus to perform the document scanning, preferably includes two point light sources located respectively at both ends of the light shield. The light shield, having a shape of lengthy hollow pipe structure, provides an internal mounting element at each end thereof for installing thereinside the respective point light source. One feature of the present invention is that the light shield includes a long slot located along a longitudinal direction thereof for transforming the lights provided by the inside point light sources into a line light source for performing the illuminating of a document. In addition, the interior wall surface of the light shield is formed as a diffusion surface for evenly diffusing the lights emitted by the point light sources, and thus a homogeneous line light source can be provided through the long slot to perform the document illuminating.
According to the present invention, the diffusion surface inside the light shield can be formed by a plurality of ring protrusions. In theory of optics, the ring protrusion can provide even diffusion upon the incoming point light source, so that homogeneous line light source can be produced through the long slot, even though point light sources does be applied as the real light source inside the light shield. In the present invention, the lights emitted by the point light sources might travel a substantial period and experience several diffusion inside the light shield before leaving the light shield through the long slot, so that the light quality provided by the light source mechanism of the present invention can be better than that provided by the conventional light source; though two separate point light sources might be used inside the light shield of the present invention.
All these objects are achieved by the light source mechanism for an imaging apparatus machine described below.
The present invention will now be specified with reference to its preferred embodiment illustrated in the drawings, in which
FIG. 1A and
The invention disclosed herein is directed to a light source mechanism for an imaging apparatus. In the following description, numerous details are set forth in order to provide a thorough understanding of the present invention. It will be appreciated by one skilled in the art that variations of these specific details are possible while still achieving the results of the present invention. In other instance, well-known components are not described in detail in order not to unnecessarily obscure the present invention.
Referring now to
The light source mechanism 2 as shown includes a single point light source 21 and a light shield 22. The point light source 21 can be a light emitting diode (LED) which has advantages of low cost, longer life term, stable illumination and a wider wave range for application. To meet the requirement of the line light source for scanning the document, the light source mechanism 2 of the present invention utilizes the light shield 22 to transform the lights of the point light source 21 into an applicable line lights.
As shown in
Referring now to
Though the point light source 21 of the present invention is mounted at one end of the light shield 22, yet localized illumination of the light source mechanism adjacent to the point light source 21 can be avoided because lights through the long slot 224 might have experienced several diffusions inside the light shield 22.
Though the light source mechanism 2 of the present invention can utilize the light shield 22 to perform a homogeneous line light source through the long slot 224 for further illuminating upon the document, yet it is still believed that slight localized illumination phenomenon might exist at the area close to the point source 21 inside the light shield 22. Also, the phenomenon will become vague as the distance from the point light source 21 increases.
To resolve the aforesaid problem and to obtain a much improved quality line light source from the long slot 224, one of the solutions is to increase the diffusion ability of the ring protrusion 226 as its respective distance from the point light source 21 increases. Under such an arrangement, the illumination adjacent to the point light source 21 will be decreased a little bit due to the decrease in the diffusion ability of the ring protrusions 226 therearound. On the other hand, the illumination of the location distant from the point light source 21 will be increased slightly due to the increase in the diffusion ability of the ring protrusions 226 therearound. By proper adjustment upon the diffusion ability of the ring protrusions 226, the line light quality from the long slot 224 of the light shield 22 can be improved further, and so as the scanning quality.
Referring now to
In the second embodiment, the light source mechanism 2a can include two point light source 21a and 21b, and a light shield 22a. The point light source 21a or 21b can be a light emitting diode (LED) which, as said in previous description, has advantages of low cost, longer life term, stable illumination and a wider wave range for application. These two point light sources 21a and 21b are preferably mounted to opposing ends of the light shield 22a.
As shown in
Referring now again back to
Nevertheless, illustration adjacent to the point light sources 21a and 21b are still higher than that in the middle of the light shield 22a. To overcome such localized illumination problem of the light source mechanism 2a, the diffusion ability of the ring protrusions 226 adjacent to the point light sources 21a and 21b can be reduced and, on the other hand, that of the ring protrusions 226 in the middle of the light shield 22a can be increased. Under such an arrangement, the illumination adjacent to the point light sources 21a and 21b will be decreased a little bit due to the decrease in the diffusion ability of the ring protrusions 226 therearound. On the other hand, the illumination of the middle portion of the light shield 22a will be increased slightly due to the increase in the diffusion ability of the ring protrusions 226 therearound. By proper adjustment upon the diffusion ability of the ring protrusions 226, the line light quality from the long slot 224a of the light shield 22a can be improved further, and so as the scanning quality.
While the present invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be without departing from the spirit and scope of the present invention.
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|Citing Patent||Filing date||Publication date||Applicant||Title|
|US8240902 *||Feb 22, 2007||Aug 14, 2012||Rohm Co., Ltd.||LED linear light source and devices using such source|
|US20090219586 *||Feb 22, 2007||Sep 3, 2009||Rohm Co., Ltd.||Linear Light Source Device, and Image Reading Device and Planar Display Device Using the Linear Light Source Device|
|U.S. Classification||358/509, 362/351, 358/484, 362/355, 358/475, 362/223, 362/311.01|
|International Classification||H04N1/028, H04N1/46, F21V3/00, F21V11/00, H04N1/04, F21V5/00|
|Cooperative Classification||H04N1/0284, H04N1/02885, H04N1/02815|
|European Classification||H04N1/028E2D, H04N1/028E5, H04N1/028E|
|Aug 14, 2009||AS||Assignment|
Owner name: TRANSPACIFIC SYSTEMS, LLC, DELAWARE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TRANSPACIFIC IP LTD.;REEL/FRAME:023107/0267
Effective date: 20090618
|Apr 22, 2011||FPAY||Fee payment|
Year of fee payment: 8
|Jun 17, 2013||AS||Assignment|
Owner name: TITUSVILLE CANAVERAL LLC, DELAWARE
Free format text: MERGER;ASSIGNOR:TRANSPACIFIC SYSTEMS, LLC;REEL/FRAME:030628/0681
Effective date: 20130213
|Jun 18, 2013||AS||Assignment|
Owner name: INTELLECTUAL VENTURES I LLC, DELAWARE
Free format text: MERGER;ASSIGNOR:TITUSVILLE CANAVERAL LLC;REEL/FRAME:030639/0330
Effective date: 20130214
|Apr 24, 2015||FPAY||Fee payment|
Year of fee payment: 12