# Patent

## Title
Scanner carrier

## Abstract

A carrier device for a contact image sense optical scanner. The carrier device incorporates a pair of magnets with identical poles facing each other or a fluid filled sealed chamber for exerting an equal pressure on a scanning module within the scanner and maintaining close contact with a document platform throughout a scanning operation.

## Background
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a scanner carrier. More particularly, the present invention relates to a carrier structure inside the scanning module of a contact image sensor (CIS) type optical scanner.
2. Description of Related Art
Contact image sensor (CIS) is a type of linear scanner commonly used for scanning an image or a document. The image or document is captured in an electronic format for ease of storage, display, processing and transmission. Due to a modular design, the CIS is easy to assemble, light, compact and costs less to produce.
FIG. 1a is a front view of the scanning module of a conventional contact image sensor and FIG. 1b is a cross-sectional view of the scanning module. As shown in FIGS. 1a and 1b, a conventional contact image sensor (CIS) 100 consists of a linear light source 104, a self-focus lens array 101 and a sensing array 102 over a substrate board 103. The light source 104, the self-focus lens array 101, the sensing array and the substrate board 103 are mounted on an aluminum frame 105. In a scanning operation, the self-focus lens array 101 reflects light coming from the original document and forms an image on the sensing array 102. The sensing array 102 converts a line of color or gray scale light into electronic signals. Throughout the scanning session, the scanning surface 110 of the scanning module 100 in constant contact with a document platform 200 via a buffer plate 300 is pulled forward or backward by an electric motor.
The convention CIS scanning module 100 uses the buffer plate 300 for close contact between the scanning surface 110 and the document platform 200. In general, an external locking mechanism or supporting element is present to ensure a close contact between the scanning module 100 and the document platform 200 during scanning movement. However, the locking mechanism or supporting element is a mechanical prop that only provides support in a few fixed locations on the scanning module 100. Hence, close contact everywhere with the document platform cannot be ensured.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a scanner carrier that provides a high-quality scanning operation. The scan carrier utilizes the repulsive forces brought about by the identical pole pieces of a pair of magnet or the pressure produced by liquid or gas to ensure a close contact between the scanning module of a contact image sense scanning module and a document platform.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a carrier device for an optical scanner. The optical scanner at least includes a document platform. The carrier device comprises a base, a contact image sense (CIS) scanning module, a first magnet, a second magnet and a plurality of buffer plates. The base is shaped like an open trough. The first magnet is at the bottom of the open trough. The scanning module enclosed inside the open trough has a scanning surface. The scanning surface heads towards the exterior of the open trough and faces the document platform. The second magnet is attached to the exterior surface at the bottom of the scanning module facing the interior of the open trough. The second magnet has an area roughly equal to the bottom surface of the scanning module. The second magnet and the first magnet are roughly of equal size. Furthermore, the first and the second magnet are arranged to have identical polarity facing each other so that the magnets together set up a repulsive force. Since the second magnet is attached to the exterior surface at the bottom of the scanning module, the scanning module is pressured by a magnetic repulsion with the first magnet. The buffer plates are attached to the inner edge of the scanning surface in contact with the document platform.
The invention also provides a second carrier device for an optical scanner. The optical scanner at least includes a document platform. The carrier device comprises a base, a contact image sense (CIS) scanning module, a seal ring and a plurality of buffer plates. The base is shaped like an open trough. The scanning module has a scanning surface that heads towards the exterior of the open trough and faces the document platform. There is a gap between the four walls of the open trough and the scanning module. The seal ring is inserted into the gap such that the space enclosed by the four sidewalls of the open trough and the exterior surface near the bottom of the scanning module are sealed. The sealed space is filled with a fluid. The buffer plates are attached to the inner edge of the scanning surface in contact with the document platform. The fluid filling the sealed space may be a liquid or a gas.
One major aspect of this invention is the utilization of magnetic repulsion between a pair of identical magnet to press the CIS scanning module tightly against the document platform so that a better scanning quality is obtained.
A second aspect of this invention is the utilization of fluid pressure acting through a sealed chamber to press the CIS scanning module tightly and uniformly against the document platform so that a better scanning quality is obtained.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.



BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
FIG. 1a is a front view of the scanning module of a conventional contact image sensor;
FIG. 1b is a cross-sectional view of the scanning module of the contact image sensor shown in FIG. 1a; 
FIG. 2a is a perspective view showing all the components of a carrier device of a CIS scanning module according to a first embodiment of this invention;
FIG. 2b is a cross-sectional view of the assembled carried device of the CIS scanning module according to the first embodiment of this invention; and
FIG. 3 is a cross-sectional view of an assembled carrier device of a CIS scanning module according to a second embodiment of this invention.



DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
FIG. 2a is a perspective view showing all the components of a carrier device of a CIS scanning module according to a first embodiment of this invention. FIG. 2b is a cross-sectional view of the assembled carried device of the CIS scanning module according to the first embodiment of this invention. As shown in FIGS. 2a and 2b, the carrier device of the CIS scanning module includes a carrier base 1400, a first magnet 1510, a CIS scanning module 1100 and a plurality of buffer plates 1300. The carrier base 1400 has an open trough shape. The first magnet 1510 is attached to the interior surface at the bottom of the carrier base 1400. The second magnet 1500 is attached to the exterior surface at the bottom of the CIS scanning module 1100 facing the first magnet 1510. The polarity of the first and the second magnet are arranged to have identical pole types and are facing each other. Hence, the repulsive force caused by the repulsion between the first and the second magnet pushes the scanning module 1100 up. The trough opening of the base carrier 1400 is only slightly greater than the external dimension of the scanning module 1100 so that movement of the scanning module 1100 is limited to vertical up/down motion. The buffer plates 1300 are attached to the interior edge of the scanning surface 1110 above the CIS scanning module 1100. Through the buffer plates 1300, the CIS scanning module 1100 is pressed tightly against a document platform 1200.
Since the repulsive forces resulting from the magnetic repulsion act uniformly across the bottom surface of the scanning module 1100, the CIS scanning module 1100 is able to press against the document platform tightly.
FIG. 3 is a cross-sectional view of an assembled carrier device of a CIS scanning module according to a second embodiment of this invention. As shown in FIG. 3, the contact image sense (CIS) scanning module 1100 is enclosed within the trough interior of a carrier base 1400. A seal ring 1700 encloses the space between the four vertical sidewalls of the scanning module 1100 and the four interior sidewalls of the carrier base 1400, thereby forming a sealed chamber. A fluid 1600 is injected to fill the sealed chamber. The fluid 1600 can be a liquid or a pressurized gas, for example. Weight of the scanning module 1100 is supported by fluid pressure inside the sealed chamber. Through a pipeline 1810, the sealed chamber within the base carrier 1400 is connected to a pump 1800 so that the pump 1800 is able to regulate fluid pressure within the sealed chamber. The buffer plates 1300 are attached to the interior edge of a scanning surface 1110 above the CIS scanning module 1100. Through the buffer plates 1300, the CIS scanning module 1100 is pressed tightly against a document platform 1200.
Since the fluid 1600 is able to provide exert equal pressure on the bottom surface of the CIS scanning module 1100, the scanning module 1100 is able to press against the document platform tightly.
In conclusion, major advantages of this invention include:
1. Magnetic repulsion between a pair of identical magnets is utilized to provide the necessary pressure for pressing the CIS scanning module tightly against the document platform and obtain a better scanning quality.
2. Alternatively, fluid pressure acting through a sealed chamber is utilized to provide the necessary pressure for pressing the CIS scanning module tightly against the document platform and obtain a better scanning quality.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

## Claims

1. A carrier device for an optical scanner at least having a document platform, the carrier device comprising:
a trough-shaped base having a trough opening and a first magnet at a bottom of the trough opening; 
a contact image sense (CIS) scanning module having a scanning surface, wherein the CIS scanning module is enclosed within the trough opening with the scanning surface of the scanning module near the trough opening and facing the document platform; 
a second magnet attached to a bottom surface of the CIS scanning module, wherein the second magnet occupies an area comparable in size to the bottom surface of the CIS scanning module, and the second magnet and the first magnet face each other such that respective identical poles thereof face each other and produce a repulsion for supporting the CIS scanning module; and 
a plurality of buffer plates attached to interior edges of the scanning surface in contact with the document platform.

2. The carrier device of claim 1, wherein the CIS scanning module may move up or down relative to the bottom of the base within the trough opening.

3. A carrier device for an optical scanner having at least a document platform, the carrier device comprising:
a trough-shaped base having a trough opening; 
a contact image sense (CIS) scanning module having a scanning surface, wherein the CIS scanning module is enclosed within the trough opening with the scanning surface of the scanning module near the trough opening and facing the document platform, and a gap exists between four sidewalls of the trough opening and sides of the CIS scanning module; 
a seal ring plugged into the gap to form an sealed chamber between the four sidewalls of the trough opening and the CIS scanning module, wherein the sealed chamber contains a fluid; and 
a plurality of buffer plates attached to interior edges of the scanning surface in contact with the document platform.

4. The carrier device of claim 3, wherein the CIS scanning module may move up or down relative to the bottom of the base within the trough opening.

5. The carrier device of claim 3, wherein the fluid includes a liquid.

6. The carrier device of claim 3, wherein the fluid includes a pressurized gas.

7. The carrier device of claim 3, wherein the sealed chamber further includes a pipeline connected to a pump so that pressure of the fluid within the sealed chamber may be regulated.