Apparatus having a light source for a transparent sheet of a scanner

The present invention relates to an apparatus having a light source for a transparent sheet of a scanner that includes a lamp, a reflective plate, a spreading plate and a protective plate. The light rays emitted by the lamp are used to scan a transparent sheet, the reflective plate in the arc shape reflects the light rays onto the scanning platform and there is an aperture on the predetermined position of the reflective plate to decrease the illumination for distributing uniformly the light rays. Besides, the spreading plate has a plurality of perforations to advance the light rays distributed uniformly. The protective plate made of the material pervious to light protects the components of this invention. As those described above, there are many advantages for the present invention, such as the structure is simple, the cost is low, and is much practical and can highly improve the performance of a scanner for a transparent sheet.

BACKGOUND OF THE INVEINTION

1. Field of the Invention

The invention relates to an apparatus having a light source for a transparent sheet, especially to an apparatus having a light source for a transparent sheet of a scanner with lower cost and highly uniform illumination.

2. Description of the Prior Art

The technology of obtaining the digital data by a scanner to scan the paper is highly developed and the scanner scans the transparent sheet such as transparency, negative, and slides by appropriate light source (“Transparency Adaptor, TA” ) to provide additional light rays. The structure of “Transparency Adaptor” describes as follow:

Refer to FIGS1A &1B, a conventional scanner1comprises a lower shell object10and an upper shell object11, the lower shell object10usually has an image adaptor module12, a transmission motor14and a transmission axle15; image adaptor module12has a lamp120, a reflective plate121, a lens122and an image sensor device123; the scanner1scans the reflective sheet and obtains a digital data by only using the aforementioned components, the detailed steps are not mentioned here. If the user wants to scan the transparent sheet, a “Transparency Adaptor”13should be installed into the upper shell object11. It is clearly shown in FIG1B, the “Transparency Adaptor”13has a lamp130, a transmission motor131and a transmission axle132. When the transparent sheet2is placed on the scanning plafform101, the light rays produced by the lamp130pass through the transparent sheet2and the images of the transparent sheet pass through the reflective plate121, the lens122and are formed in the imagine image sensor device123. Then the image sensor device123converts the images into the digital data for output. Then the transmission motor14drives the imagine adopter image adaptor module12to move along the direction of the transmission axle15(as the arrow shown in FIG IB), in the meantime, the lamp130of the “Transparency Adaptor”13is driven synchronally by the transmission motor131and moved forward along the direction of the transmission axle132. By the actions aforementioned, each portion of the transparent sheet has been exposed and converts digital data for output.

The other conventional Transparency Adaptor is as shown in FIGS2A &2B. Most components of the scanner I as shown in the FIGS2A &2B are as-the same as those of the scanner1as shown in the FIGS1A &1B, the difference is that the transparency adaptor16of the upper shell object11comprises a lamp160and a light-conducting plate161. The light-conducting plate161is used to distribute uniformly the light rays produced by the lamp160, so the transparency adaptor16provides the light rays for the transparent sheet2without driven by a transmission motor. We obtain easily the digital data output by the image sensor device123, when the transmission motor14drives the imagine image adaptor module12to move along the direction of the transmission axle15.

The first kind of the conventional Transparency Adaptor aforementioned uses a lamp illuminating the reflective sheet directly, the light rays for the imagine image sensor device123is stronger and the digital data output is better, but it needs a lot of components and complex structures, such as the transmission motor and the transmission axle, which increase the difficulty and the cost of combining the scanner. Oppositely, the second kind of the Transparency Adaptor which can decrease the difficulty and the cost of combining the scanner, but the light rays passing through the light-conducting plate is not efficiently and uniformly, the quality of the digital image output from the imagine-image sensor device cannot be improved.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to improve the quality of the digital image output from the image sensor device by obtaining highly uniform light rays for a transparent sheet of a scanner.

It is the other object of the present invention is to provide an apparatus having a light source for a transparent sheet of a scanner with low cost and easily combining.

Base on the aforementioned idea, the present invention provides an apparatus having a light source for a transparent sheet of a scanner that comprises a shell object, a light-emitting element inside the shell object for emitting light, a reflective plate which is between the shell object and the light-emitting element to reflect the light emitted by the light-emitting element, and an aperture on the first predetermined position of the reflective plate for decreasing the illumination of the first predetermined position.

Base on the idea aforementioned, wherein the light-emitting element is a lamp or a LED array.

Base on the idea described above, wherein the reflective plate is in the arc or “Π” shape.

Base on the idea aforementioned, wherein an aperture's central part is wider than its two ends.

Base on the idea described above, wherein the apparatus having the light source for a transparent sheet of a scanner further comprises a spreading plate which is a thin film between the light-emitting element and the reflective plate to cover the light-emitting element for spreading the light rays passing through it.

Base on the idea aforementioned, wherein the spreading plate has a plurality of perforations for decreasing illumination of the second predetermined position by increasing the perforations of the second predetermined position.

Base on the idea described above, wherein the apparatus having the light source for a transparent sheet of a scanner further comprises a protective plate made of the material pervious to light, which is at the surface of the shell object to protect the light source for a transparent sheet of a scanner.

Base on the idea aforementioned, wherein the first and second predetermined positions are at the central part of the light-emitted element.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

First of all, refer to the FIG3, which is the schematic view of the scanner with a light source for a transparent sheet of a scanner of this present invention. As shown in this FIG, the scanner3composes the lower shell object30and the upper shell object31, the components of the lower shell object30(such as the image adaptor32) are the same as those of the conventional scanner; but for the reason of improving the images quality of the transparent sheet of the present invention, the transparency adaptor33within the upper shell object31uses a lamp330to emit the light rays and the reflective plate331to focus and reflect the light rays onto the scanning platform301for scanning the transparent sheet. Below is the further detailed description of the transparency adaptor of the present invention:

The preferred embodiment of the transparency adaptor33of the present invention is as shown in theFIG. 4A. In which, the apparatus having the light source for a transparent sheet of a scanner33of the present invention has a lamp330, a reflective plate331, a spreading plate332and a protective plate333and all of them are inside the upper shell object31; the lamp330as the light source emits the light rays for scanning the transparent sheet because the lamp330has the advantages of adequate brightness and lower cost, which is the appropriate light source for the present invention. Besides, a reflective plate331is put behind the lamp330and between the upper shell object31and the lamp330. The sectional schematic view of the reflective plate331is in the arc shape as shown inFIG. 4AandFIG. 4B, which can reflect the light rays from the lamp330concentrating onto the scanning platform301. For the brightness of the central part is brighter than the two ends of the lamp as the dotted line in the brightness distribution figure shown inFIG. 4C, therefore, an aperture334, its central part is wider than the two ends, is on the reflective plate331as shown inFIG. 4B, the aperture334leaks some light rays of the lamp330and prevent them from reflecting onto the scanning platform301, which balances the brightness of the central part and the two ends of the lamp330, as the line in the brightness distribution figure shown inFIG. 4C, the balanced brightness for scanning the transparent sheet (not shown) is helpful to improve the quality of the digital data.

Furthermore, the spreading plate332of the apparatus having the light source for a transparent sheet of a scanner33is a thin film with the function to spread uniformly the light passing through it. As shown in FIG6(an isometric exploded bottom view), it-the spreading plate332is proximate to the lamp330and the reflective plate331and covers the lamp330. The surface of the spreading plate332has several perforations for balancing the brightness of the light rays emitted by the lamp330, the present invention decreases the perforations of the spreading plate332relatively to the brighter position of the lamp330(such as the central part of the lamp330) to decrease the illumination, so the brightness of the light rays wherein will be lowered. It is opposite that increasing the perforations of the spreading plate332relatively to the darker location of the lamp330(such as the two ends of the lamp330) raises illumination, so the brightness of the light rays will be increased. By the actions described above, which can balance the light rays for the scanning platform, the quality of the digital output from the present invention will be improved as well.

In addition, the apparatus having the light source for a transparent sheet of a scanner33of the present invention has a protective plate333, which is the material made of pervious to light (such as glass), is on the surface of the upper shell object31to protect the components of the apparatus having the light source for a transparent sheet of a scanner33.

The other preferred embodiment of the apparatus having the light source for a transparent sheet of a scanner33of the present invention is as shown inFIG. 5A, wherein the most parts of the apparatus having the light source for a transparent sheet of a scanner33of the present invention are as same as those described above, but the sectional schematic view of the reflective plate331′ is in the “Π” shape as shown inFIGS. 5A and 5B, which can reflect the light rays from the lamp concentrating onto the scanning platform301, and the reflective plate331′ of this preferred embodiment is easier to compose; but the brightness of the lamp330passing through the reflective plate331′ will be distributed as the dotted line shown inFIG. 4C, therefore, the present invention places two apertures334′ on the reflective plate331′, these apertures'334′ central parts are also wider than the two ends as shown inFIG. 5B, which can decrease the brightness of the central part of the lamp330and balance the distribution of the brightness as the line shown inFIG. 5C, it is helpful to improve the quality of the digital data output by the balanced distributing brightness of light rays for scanning the transparent sheet.

In one embodiment, the lamp330of the present invention as described above may comprise a LED array, which can meet the purpose of the present invention. For example. referring now toFIG. 7. there is illustrated vet another preferred embodiment of The claimed subject matter. In this et another referred embodiment scanner33includes a Ii ht source335which a comprise a light emitting element such as a Ii ht emitting diode LED array, for example. Scanner33may comprise additional components such as an upper shell object31a reflective plate331. a spreading plate332and a protective plate333. for example. These components may be the same or similar as components described previously. for example.

As those described above, the present invention uses a lamp as the light source, a reflective plate to reflect the light rays onto the scanning platform, the aperture to improve the light rays uniformly, in the meantime, it uses the spreading plate to finely adjust the distribution of the light rays uniformly. There are many advantages for the present invention that the components are simple, the cost is low, and it is more practical and can highly improve the performance of a scanner to scan the transparent sheet.

Aforementioned are the preferred embodiments of the present invention, these preferred embodiments are used to explained but limit the claim of the present invention. The scope of the present invention is defined by the claims described as follow. The variations and/or modifications according to the claims of the present invention should be contained by the present invention.