CN2758805Y - Flatbed Scanner with Correctable Focus - Google Patents

Abstract

The utility model provides a but platform formula scanner of focal length of correction, be used for focusing, place scanning element on the glass platform in platform formula scanner earlier, utilize a light source to shine scanning element, make scanning element send light in order to incide to a camera lens, this camera lens incides light to a sensor again, make sensor lens received light and produce an image, still be provided with a flat glass in platform formula scanner, when scanning element is for piercing through the manuscript, just, move flat glass to between camera lens and sensor, make light after the camera lens reflection, incide to flat glass earlier, through flat glass again in order to produce the image through the sensor reception. The utility model discloses utilize a flat glass to scan the focusing when penetrating the manuscript for need not remove camera lens or sensor position, alright make the reflection manuscript and the formation of image position that penetrates the manuscript all be located the sensor, and reach the correction of focusing.

Description

Flatbed Scanner with Correctable Focus

technical field

The utility model relates to a platform scanner, in particular to a platform scanner which can correct the focal length without moving the position of the lens or sensor.

Background technique

For the documents left in the past, because the technology has not yet developed enough to develop electronic files or when the electronic files are lost, in order to save the files, the files must be scanned into electronic files to obtain effective preservation. Therefore, the scanner also It has gradually become an important product in today's technology.

Generally speaking, common scanners are roughly divided into Handy scanners, Sheetfed Scanners, Flatbed Scanners, Pilm Scanners and drum scanners. (Drum Scanner), among which the platform scanner is the most popular, which scans through the internal photoelectric unit, and can scan almost all types of documents, from books, newspapers and magazines, and even coke cans, as long as they can be placed on the platform Objects placed on the glass of the flatbed scanner can be scanned, coupled with the high speed, stable image quality and low price of the flatbed scanner, it is very popular among the public. Therefore, in recent years, with the development of related accessories, such as : Reticle, film holder, etc. The flatbed scanner can also support transparencies, and can also scan slides, positive and negative films, etc.

When a general flatbed scanner scans the film that penetrates the manuscript, in order to facilitate the user's operation, it will use a film holder to hold the film object to be scanned, and then place it on the The document of the scanner is placed on the glass for transmissive scanning, but because of the actual thickness of the film holder, the transmissive document to be scanned cannot be flattened on the document placement glass like a normal reflective document, as shown in Figure 1 As shown, the transmissive manuscript position 102 will be offset by a distance Δd from the reflective manuscript position 104, causing the transmissive manuscript imaging position 106 to fall in front of the reflective manuscript imaging position 108 by ΔL, thus causing defocusing. Low-resolution machines can be overcome by the depth of field of the lens, but as the resolution of the scanner becomes higher and higher, the depth of field of the lens becomes shorter and shorter, and this defocus problem will cause difficulties in lens design.

Therefore, the present invention aims at the above problems, and proposes a focus-correctable platform scanner to improve the above defects.

Utility model content

The main purpose of the present utility model is to provide a flatbed scanner capable of correcting the focal length, which utilizes a plate glass to add the plate glass when scanning the penetrating manuscript to adjust the focal length position for focusing, so that the On the premise that the position of the lens or the sensor needs to be moved, the imaging positions of the reflective manuscript and the transparent manuscript are all located on the sensor.

In order to achieve the above-mentioned purpose, the utility model proposes a flatbed scanner capable of correcting the focal length, which is used for focusing. A light source is arranged in the flatbed scanner, and the light source is used to irradiate a person placed on a flatbed scanner. The document is scanned on the glass platform on the scanner, so that the scanning element generates light incident to a lens, and the lens reflects the light and receives it through a sensor to generate an image. A flat glass is also arranged in the platform scanner. When the scanning element is a penetrating document, the plate glass can be moved between the lens and the sensor so that the light enters the lens, and the lens reflects the light to pass through the plate glass and be received by the sensor to generate an image.

In the following, a detailed description will be made through specific embodiments and accompanying drawings, so that it will be easier to understand the purpose, technical content, characteristics and effects of the present utility model.

Description of drawings

FIG. 1 is a schematic diagram of an optical path of an existing flatbed scanner;

Figure 2 is a schematic diagram of the internal structure of the platform scanner of the present invention;

Fig. 3 is the schematic diagram of the light path of the flatbed scanner of the present invention scanning the reflective manuscript;

Fig. 4 is a schematic diagram of the optical path of the platform scanner of the present invention for scanning the penetrating manuscript;

Fig. 5 is a schematic diagram of the driving device of the present invention moving flat glass;

FIG. 6 is a schematic diagram of the focal length of the flat glass set in the flatbed scanner of the present invention.

Detailed ways

The utility model aims to improve the defocusing problem caused by the height of the film holder when the previous platform scanner scans the film. Therefore, the utility model proposes a platform scanner capable of correcting the focal length, so as to avoid moving Focusing on the premise of the lens or sensor.

Figure 2 is a schematic view of the internal structure of the flatbed scanner of the present invention. The flatbed scanner includes a glass platform 201 on which at least one scanning element is placed, and a light source 203 illuminates the scanning element to generate a reflected light , the reflected light is incident to a lens 204, which receives the reflected light and reflects it, and a sensor 205 can receive the reflected light to generate an image, or use a driving device 214 to move a flat glass 208 to the lens 204 and sense Between the device 205, the reflected light passes through the lens 204 and enters the flat glass 208, and then enters the sensor 205 to generate an image. A light source 203, a glass platform 201, a lens 204, a sensor 205, such as a charge-coupled device (CCD) and a flat glass 208, are arranged in the flatbed scanner, the light path of the flatbed scanner The schematic diagrams are shown in Figures 3 and 4. First, the schematic diagram of the optical path shown in Figure 3, when the scanning element to be scanned is a reflective manuscript, place the scanning element on the glass platform to form a reflective manuscript position 202, and use the light source Irradiate the reflective manuscript, so that the scanning element will generate light and enter the lens 204, and the lens 204 will incident the light to the sensor, and form a reflective manuscript imaging position 206 at the position of the sensor to generate an image. The plate glass 208 does not move, but when the scanning element to be scanned is a transmissive document, such as a film, the schematic diagram of the optical path is shown in Figure 4. The position of the transmissive document 210 is higher than the reflective document due to the thickness of the film holder. The position 202 is offset by a distance of Δd. Therefore, a plate glass 208 with a thickness of t is used to move between the lens 204 and the sensor, so that the transmissive imaging position 212, which was originally placed in front of the reflective imaging position 206 by a distance ΔL, Due to the influence of the flat glass 208 with a thickness t, the transparent draft imaging position 212 will move backward to the reflective draft imaging position 206 , so that the reflective draft imaging position 206 overlaps with the transparent draft imaging position 212 .

Wherein, as shown in Figure 5, the position of the flat glass 208 can be moved by a driving device 214. When the scanning element is a penetrating manuscript, the flat glass 208 is moved by the driving device 214, such as rotating to the lens 204 and sensing Between the devices, the transmissive imaging position 212 will move back to the reflective imaging position 206 to make the focal length fall at the same point, so focus correction can be achieved without moving the position of the lens 204 or the sensor.

In addition, the thickness of the above-mentioned plate glass 208 is optically calculated through the design of the lens 204, and the actual value is indeed calculated. As shown in FIG. The flat glass 208 with a thickness of t moves the imaging position of the transmissive manuscript from the original A to A'. In this way, when scanning the transmissive manuscript, the focal length similar to that of scanning the reflective manuscript can be obtained without moving the sensor or Lens 204 to refocus, wherein, the thickness t of flat glass 208 is calculated by the following formula, N is the refraction number of flat glass 208, and ΔL is the distance that the position of penetrating manuscript deviates from the position of reflecting manuscript:

$\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&Delta;L</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}$

The utility model proposes a platform-type scanner capable of correcting the focal length, which utilizes a flat glass. When the scanning element is a reflective draft, no flat glass is added between the lens and the sensor. When the scanning element is a penetrating draft, A flat glass is added between the lens and the sensor, so that the original imaging position of the penetrating draft falls in the focal length of a certain distance in front of the imaging position of the reflective draft, which can be refocused without moving the position of the lens or sensor , so that the imaging positions of the reflective manuscript and the transparent manuscript are all located on the sensor, so as to achieve focus correction.

The above is to illustrate the features of the utility model by the embodiments, and its purpose is to make those skilled in the art understand the content of the utility model and implement it accordingly, rather than limit the patent scope of the utility model, so everything else does not break away from it Equivalent modifications or modifications accomplished based on the spirit disclosed in the utility model should still be included in the scope of the patent application described below.

Claims (6)

1. A flatbed scanner capable of correcting the focal length, which is used for focusing, is characterized in that the flatbed scanner includes: a glass platform on which at least one scanning element is placed; a light source for illuminating the scanning element to generate a reflected light; A lens that receives the reflected light and reflects it; a plate glass, which can receive the reflected light reflected by the lens and reflect it; A sensor is selected to receive the reflected light reflected by the lens and the plate glass, so as to receive the reflected light and generate an image; and A driving device is used for moving the position of the flat glass. 2. The focus-correctable flatbed scanner as claimed in claim 1, wherein the driving device rotates to move the flat glass. 3. The flatbed scanner capable of correcting focus as claimed in claim 1, wherein when the scanned document is a reflective document, the driving device moves the flat glass away from between the lens and the sensor to The reflected light passes through the lens and enters the sensor to generate the image. 4. The flatbed scanner capable of correcting focus as claimed in claim 1, wherein when the scanned document is a transparent document, the driving device moves the flat glass between the lens and the sensor to The reflected light passes through the flat glass and enters the sensor to generate the image. 5. The flatbed scanner capable of correcting focus as claimed in claim 4, wherein the see-through manuscript is a film. 6. The focus-correctable flatbed scanner as claimed in claim 1, wherein the sensor is a charge-coupled device.

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