CN2657039Y - Brightness enhancement device for image scanning module - Google Patents

Abstract

The utility model discloses a brightness enhancement device of image scanning module, including glass, light source and at least reflector plate, place on the glass and treat the scanning file, reflector plate reflection light source's partial light to treating on the scanning file, this reflector plate has the plane of reflection of specific curved surface shape, the light source is located the preceding focus of reflector plate, the plane of reflection makes the partial light reflection that the light source launched on it converge to first back focus, partial light reflection converges to second back focus, first back focus is separated by specific distance with second back focus, also be separated by certain distance between glass and the first back focus and the second back focus respectively, make the light that converges to first back focus and second back focus continue to disperse to treating on the scanning file, and the predetermined scope of reading at treating the scanning file forms the brightness enhancement district, in order to promote the scanning quality.

Description

Brightness enhancement device for image scanning module

technical field

The utility model relates to a brightness enhancement device of an image scanning module, in particular to a reflection sheet with a specific curved surface, which can uniformly enhance the brightness of a document reading range.

Background technique

Traditional image scanning devices, such as scanners, copiers, fax machines, etc., use a light source to directly irradiate the document to be scanned to read the document, but the light generated by this light source cannot be fully utilized. Therefore, the industry has designed A brightness enhancement device mainly includes a reflective sheet to reflect unused light onto a document, thereby enhancing the brightness of the document. Please refer to Fig. 5, which is a simple schematic diagram of part of the optical module 20 of the scanner, and its brightness enhancement device generally includes a light source 201, which can be a daylight tube or other forms of light tubes, and one side of the light source 201 A reflector 202 is pivotally arranged, and the reflector 202 is in the shape of a slope. When the light from the light source 201 hits the slope reflector 202, it will be reflected to the document, thereby enhancing the brightness of the document and improving the quality of document image reading. However, this design of reflecting light to the document by using the inclined reflector can only enhance the brightness of the document by about 1.7 times.

Please continue to refer to shown in Figure 6, which is a schematic diagram of another existing brightness enhancement device, its reflective sheet 203 has a circular reflective curved surface, and a light-condensing sheet 204 is provided at the exit of the reflective sheet 203, in order to The light from the circular reflective curved surface is concentrated on the document, and the circular reflective curved surface is used to diffuse the light to the document, which can enhance the brightness of the document by about 2 times. Referring again to FIG. 7 , the reflective sheet 205 has an elliptical reflective surface, and the elliptical curved reflective surface can enhance the brightness of the document by about 2.5 times after reflecting light to the document.

However, although the above-mentioned prior art can enhance the brightness from 1.7 times to more than 2.5 times, the range of scanning and reading documents by the optical module 20 of a general scanner is not the range of dots or lines, but the scanning and reading range of a considerable width. The range is generally about 3mm. Only when the brightness is uniformly enhanced in the entire reading range can the image sensor receive uniform and sufficient illumination when the document light passes through the lens and reach the image sensor, and better quality scanning results can be obtained. However, the above-mentioned prior art only focuses on enhancing the brightness of the dots or lines on the document, but fails to solve the problem of uniform enhancement of the brightness of the document reading range, so better scanning quality cannot be obtained.

Contents of the invention

In order to improve the above-mentioned prior art that cannot meet the brightness requirement of the image scanning module, the utility model provides a brightness enhancement device that can uniformly enhance the brightness.

In order to achieve the above purpose, the utility model provides a brightness enhancement device for an image scanning module, which includes glass, a light source and at least one reflective sheet. The document to be scanned is placed on the glass, and the reflective sheet reflects part of the light from the light source to the document to be scanned. , the reflective sheet has a reflective surface with a characteristic curved shape, the light source is located at the front focus of the reflective sheet, the reflective surface makes part of the light emitted by the light source reflect and converge to the first rear focus, and part of the light reflects and converges to the second rear focus, There is a certain distance between the first back focus and the second back focus, and there is also a certain distance between the glass and the first back focus and the second back focus, so that the light rays converging on the first back focus and the second back focus continue to diverge to the waiting area. Scan the document, and form a brightness enhancement area in the predetermined reading range of the document to be scanned.

Through the implementation of the utility model, the scanning and reading range of the document not only has the effect of enhanced brightness but also has the effect of uniform brightness, so the scanning quality can be improved.

Brief description of the drawings

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail.

FIG. 1 is a schematic diagram of a first embodiment of a brightness enhancement device of an image scanning module of the present invention;

2 is a schematic diagram of a second embodiment of the brightness enhancement device of the image scanning module of the present invention;

3 is a schematic diagram of a third embodiment of the brightness enhancement device of the image scanning module of the present invention;

4 is a schematic diagram of a fourth embodiment of the brightness enhancement device of the image scanning module of the present invention;

Fig. 5 is a simple schematic diagram of the first existing brightness enhancement device;

Fig. 6 is a simple schematic diagram of a second conventional brightness enhancement device;

Fig. 7 is a simple schematic diagram of a third conventional brightness enhancement device.

Detailed ways

The brightness enhancement device 10 of the image scanning module of the present invention can be used in scanners, copiers, facsimile machines or multi-function business machines. Please refer to FIG. 1 , the brightness enhancement device 10 of the image scanning module of this embodiment is applied to a reflective document scanner. The brightness enhancement device 10 of the image scanning module includes a glass 1, a light source 3 and a reflector 4, wherein the glass 1 is used to place the document 2 to be scanned; Located under the glass 1, the light source 3 projects light through the glass onto the document 2 to be scanned to read the document 2; the reflector 4 is arranged on the side of the light source 3 to further reflect the light to the document 2 to enhance the brightness of the document 2.

Please refer to FIG. 2 , the brightness enhancement device 10 of the image scanning module of the second embodiment of the present invention is applied to a penetrating manuscript scanner. It is different from the first embodiment in that the light source 3 is located above the glass 1 . The light is projected by the light source 3 and penetrates the document 2 to be scanned, and then projected onto the glass 1. The reflective sheet 4 is also arranged above the glass 1 on the side of the light source 3 to enhance the brightness of the light projected onto the document 2.

The inner surface of the reflective sheet 4 is a reflective surface 41 with a specific curved surface shape, the reflective surface 41 is composed of a first curved surface 421 and a second curved surface 431 connected, and the first curved surface 421 and the second curved surface 431 are located on both sides of the light source 3 . The first curved surface 421 is a part of the first elliptical cylinder, and the second curved surface 431 is a part of the second elliptic cylinder. The two foci of the first ellipse 42 are respectively the first front focus and the first back focus 422, the two foci of the second ellipse 43 are respectively the second front focus and the second back focus 432, and the first front focus and the second front focus are The same point, that is, the front focal point 423 , the center of the light source 3 is located at the front focal point 423 , and the first rear focal point 422 and the second rear focal point 432 are separated by a certain distance. The light emitted by the light source 3 to the reflective surface 41 will be reflected by the reflective surface 41, wherein the first curved surface 421 reflects and converges the light on it to the first back focus 422, and the second curved surface 431 reflects and converges the light on it to the second back focus 432 .

The first and second back focus points 422 and 432 of the first and second ellipses 42 and 43 are designed to have a certain distance from the glass 1, so the light reflected by the reflective surface 41 will pass through the first and second back focus points 422 and 432 Continue to diverge and then project to file 2, so a reading range A is formed on file 2. In this range A, not only the light emitted directly by the light source 3, but also the light reflected by the two reflecting surfaces 421 and 431 are obtained, so the brightness The enhancement can reach more than 4.0 times, and it is especially important to have relatively uniform brightness in the scanning reading range A of file 2. Similarly, if dual light sources are used, that is, two sets of brightness enhancement devices 10 of the present invention are used, the brightness enhancement can reach more than 8.0 times.

Please refer to FIG. 3 , which is the third embodiment of the brightness enhancement device 10 of the image scanning module of the present invention, which is different from the first and second embodiments in the reflective sheet structure. Basically, if the light projected by the light source 3 is to be reflected to the document 2, it will be blocked by the light source 3, so the benefit is very small. The two curved surfaces 431 are not directly connected, but between the two reflective curved surfaces 421, 431, a connecting section 44 is used to connect the two reflecting curved surfaces 421, 431 at the back of the light source 3. The connecting section 44 can be designed as a flat surface, etc., to facilitate manufacturing. simple.

Please refer to FIG. 4 , which is the fourth embodiment of the brightness enhancement device 10 of the image scanning module of the present invention, which differs from the first and second embodiments in the reflective sheet structure. The first curved surface 421 and the second curved surface 431 of the reflective sheet 4" in this embodiment are not connected at the back of the light source 3, but have gaps, so two reflective sheets 4" are formed to facilitate manufacturing.

From the description of the above structure, it can be seen that since the reflective sheet 4, 4', 4" of the present invention has a reflective surface 41 composed of the first and second curved surfaces of two different elliptical surfaces, therefore, in addition to the characteristics of the double ellipse The light irradiated by the light source 3 to the file is enhanced to more than 4 times the brightness. If the light source 3 is designed as a double fluorescent tube, the enhancement of the brightness is even more impressive. In addition, through the two reflective curved surfaces 421, 431 the light is concentrated to the first and second The rear focal points 422 and 432 diverge and project onto the document 2, so that the scanning range A of the document 2 not only has an enhanced brightness but also has an even brightness effect, so that the purpose of improving the scanning quality can be achieved.

Claims (8)

1. A brightness enhancement device for an image scanning module, which includes glass, a light source and at least one reflector, on which a document to be scanned is placed, and the reflector reflects part of the light from the light source to the document to be scanned, characterized in that: the The reflective sheet has a reflective surface with a specific curved shape. The light source is located at the front focus of the reflective sheet. The reflective surface makes part of the light emitted by the light source reflect and converge to the first rear focus, and part of the light reflects and converges to the second rear focus. There is a certain distance between the back focus and the second back focus, and a certain distance between the glass and the first back focus and the second back focus, so that the light that converges to the first back focus and the second back focus continues to diverge to the document to be scanned , and form a brightness enhancement area in the predetermined reading range of the document to be scanned. 2 . The brightness enhancement device of an image scanning module according to claim 1 , wherein the reflective surface is at least composed of a first curved surface and a second curved surface, and the first curved surface and the second curved surface are located on two sides of the light source. 3. The brightness enhancement device of an image scanning module according to claim 2, wherein the first curved surface is a part of an elliptical cylinder, the front focus and the first back focus are two foci of the ellipse, The second curved surface is a part of another elliptical cylinder, and the front focus and the second back focus are two foci of the ellipse. 4 . The brightness enhancement device of an image scanning module according to claim 1 , wherein the light source is located under the glass, and the first back focus and the second back focus are also located under the glass. 5. The brightness enhancement device of an image scanning module according to claim 1, wherein the light source is located above the glass, and the first back focus and the second back focus are also located above the glass. 6. The brightness enhancement device of an image scanning module according to claim 1, wherein the reflective surface is composed of a first curved surface, a second curved surface, and a connecting section connecting the first curved surface and the second curved surface, and the first curved surface The second curved surface is located on both sides of the light source, and the connecting segment is located at the back of the light source. 7. The brightness enhancement device of an image scanning module according to claim 6, wherein the connecting section is a flat surface. 8. The brightness enhancement device of an image scanning module according to claim 1, wherein the reflective surface is composed of a first curved surface and a second curved surface, and the first curved surface and the second curved surface are located at the back of the light source. connected to form gaps.

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