Flatbed image scanners are widely used in offices or homes for scanning for example documents, photographs or films. The scanned images can be converted into electronic file, which can be directly stored in a computer or further processed by the computer. Referring to FIG. 1(a), a schematic view of a flatbed image scanner is shown. As shown in FIG. 1(a), the flatbed image scanner 1 comprises a transparent platform 11 and an optical scanning module 13. The transparent platform 11 is used for placing thereon the object 12 to be scanned. The optical scanning module 13 is the main component of the flatbed image scanner 1. After the object 12 is placed on the transparent platform 11, the optical scanning module 13 is moved along the scanning direction so as to scan the object. The scanned images of the object 12 are then inputted into a computer and processed by the computer.
Please refer to FIG. 1(b), which is a cross-sectional side view illustrating the internal components of the optical scanning module 13. In the housing 130 of the optical scanning module 13, a light source 131, a reflective mirror set 132, an optical lens 133 and an optical sensor 134 are provided. A light-transmissible window 135 is arranged in the top surface of the housing 130. The process for performing a scanning operation will be illustrated as follows. Firstly, the light emitted by the light source 131 is projected onto the object 12 to be scanned. The light reflected from the opaque object 14 is then transmitted into the optical scanning module 13 through the light-transmissible window 135, which is arranged in the top surface of the housing 130. After passing through the light-transmissible window 135, the light is successively reflected by the plural reflective mirrors of the reflective mirror set 132, and then focused by the optical lens 133. The focused light is then imaged onto the optical sensor 134 to convert the optical signals reflected from the scanned object 12 into corresponding image signals.
As known, heat is generated during the optical scanning module performs the scanning operation. On the other hand, in a case an image scanner having relatively large volume and ordinary resolution, the electronic components included in the optical scanning module, for example the optical sensor, are not evidently and adversely influenced by the heat generation.
Since the image scanner is developed toward increased resolution and slim volume, the heat generated from the optical scanning module may impair the scanning quality of the image scanner. Therefore, it is desired to remove the heat generated from the optical scanning module.
An optical scanning module having a heat-dissipating device is described in Taiwanese Patent Gazette No. 520822, entitled “Heat-dissipating device of optical sensor and optical scanning module” and the contents of which are hereby incorporated by reference. A cross-sectional side view of the optical scanning module as disclosed in Taiwanese Patent Gazette No. 520822 is illustrated in FIG. 2. As shown in FIG. 2, a heat-dissipating device 236 is disposed on the back side of the optical sensor 234 of the optical scanning module 23. The heat-dissipating device 236 includes a heat conducting pipe 2361 filled with a cooling solution therein and a plurality of heat-dissipating sheets 2362. During scanning operation, the heat generated from the optical sensor 234 of the optical scanning module 23 is adsorbed by the cooling solution contained in the heat conducting pipe 2361 and then conducted to the heat-dissipating sheets 2362. The heat is radiated from the heat-dissipating sheets 2362 to the ambient air so as to achieve the object of heat dissipation. Unfortunately, since the heat conducting pipe and the heat-dissipating sheets 2362 occupy much space of the optical scanning module, the image scanner fails to be made in a slim type.
In views of the above-described disadvantages of the prior art, the applicant keeps on carving unflaggingly to develop an improved optical scanning module according to the present invention through wholehearted experience and research.