CN1267036A - Image scanner - Google Patents

Abstract

An image scanner is composed of a casing, a scan platform with a flat surface as bearing surface, several clamps arranged at both sides of said scan platform, a scan module fixed to said guide element and containing photoelectric converter module for converting the image of document to be scanned to electric signals, and a drive mechanism for driving said scan module to move along the longitudinal direction of scan platform. The invention can solve the problem that the depth of field between the conventional scanning module and the document to be scanned is difficult to maintain, and reduce the complexity of the transmission mechanism of the scanning module and the difficulty of assembly.

Description

image scanner

The invention relates to an image scanner, in particular to an image scanner with a depth of field maintaining device for maintaining a fixed depth of field of a scanning mold.

It is known to use an image scanner to convert the image of the document to be scanned into a corresponding image signal, and one of the factors affecting the image quality is how to keep a certain depth of field between the scanning module and the document to be scanned when scanning. And this problem is most obvious in the mobile scanning module that moves continuously during the image scanning process, such as the flatbed image scanner is an example of this type of image scanning machine.

Referring to FIG. 1 , it is a schematic diagram of the structure of a traditional flat-bed image scanner, which has an upper cover 10 for flattening documents to be scanned; a housing 20, which has a transparent glass 22 as a platform for carrying documents or pictures to be scanned ; A scanning module (CCD or CIS) 40 is an image sensing element in which the image light signal is converted into an electronic signal; an axis 31 is fixed on the housing 20 parallel to the longitudinal direction of the transparent glass 22; and a drive The device 32 is used to guide the scanning module 40 to move along the rotating shaft 31 to scan the document to be scanned.

According to the structure of the above-mentioned scanner, in the installation process of the scanner, in order to maintain a certain depth of field between the scanning module 40 and the document to be scanned during the scanning process, the distance between the transparent glass 22 and the rotating shaft 31 must be carefully adjusted or corrected. However, due to the processing and installation factors of the two, it is easy to cause difficulties in calibration and adjustment, which makes it difficult to maintain a constant depth of field between the scanning module 40 and the document to be scanned, resulting in poor scanning quality, especially for the CIS module. The depth of field is very shallow, and the change of the depth of field has a greater impact on the image quality; at the same time, because the conventional driving device 32 is used with a roller set and a belt or a steel wire, it is easy to cause difficulties in assembly and adjustment.

The main purpose of the present invention is to provide an image scanner, which solves the conventional problem that the depth of field between the scanning module and the document to be scanned is difficult to maintain.

Another object of the present invention is to provide an image scanner, which solves the problem of difficulty in calibration and production caused by the different reference planes of the document to be scanned and the scanning module.

Another object of the present invention is to provide an image scanner, which reduces the complexity of the transmission mechanism of the scanning module and the difficulty of assembly.

The object of the present invention is achieved in this way: an image scanner, which includes a housing, a scanning platform with a flat surface as a bearing surface, and its guide element is composed of several clamps and is slidably arranged on the scanning platform. The two sides of the platform move along the longitudinal direction of the scanning platform; the scanning module is fixed on the guiding element and includes a photoelectric conversion module to convert the image of the document to be scanned into a corresponding electrical signal , and the driving mechanism is used to drive the scanning module to move along the longitudinal direction of the scanning platform.

It also includes an upper cover for flattening the document to be scanned on the scanning platform.

The scanning platform has protruding edges at both ends in the scanning line direction.

The cross-section of the fixture is roughly U-shaped, and the openings thereof are opposite to each other, and can just clamp the protruding edge of the scanning platform.

A contact element for contacting the protruding edge of the scan is also provided inside the fixture.

The contact surfaces of the contact elements are low-friction number surfaces.

A damper for buffering the torque generated by the movement of the scanning module can be further arranged inside the fixture.

The damper is a spring.

The motor of the driving device is arranged on the scanning module; the reduction gear set for outputting the power of the motor is matched with the motor; a rack is fixed on the housing and meshed with the reduction gear set.

According to the technology disclosed in the present invention, the carrying surface of the document to be scanned is used as the moving reference surface of the scanning module, and a guide element arranged on the carrying surface is provided. This guiding element is also connected to the scanning module, so that the scanning During the scanning movement of the module along the bearing surface, the guide elements can be maintained to keep a certain distance from the bearing surface, so as to maintain the scanning depth of field, and improve the adjustment of all related parameters when the scanner is assembled. Baseline issues. And according to the solution of the present invention, the driving device (such as a motor or a reduction gear) for driving the scanning module is arranged on the scanning module, and a reference plane (such as a gear tooth) that is relatively immovable with the image scanner is set in cooperation with the scanning module. bar), the reduction gear of the driving device is meshed with the rack to become a driving device for moving the scanning module.

Compared with prior art, the present invention has following advantage:

1. Since the present invention fixes the scanning module on the surface of the scanning platform by means of a guide element, the scanning module can move relatively parallel to the scanning platform during the scanning process, so that the document to be scanned can be aligned with the scanning module. A certain depth of field is maintained between them, and since the transmission method of the present invention takes the scanning platform as the scanning reference plane, it can not only avoid the conventional method of using shafts and placing them on different parts, which leads to the need to adjust each related reference plane, but also It can improve the control of the depth of field and the quality problem of image distortion during the scanning process.

2. Since the present invention only uses a guide element to fix the scanning module on the surface of the scanning platform, so as to achieve the purpose of maintaining a fixed depth of field and not requiring adjustment, there is no major change to the structure of the original scanner, so parts can be saved The quantity and volume, thereby reducing the manufacturing cost.

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

FIG. 1 is a schematic diagram of the structure of a traditional flatbed scanner.

FIG. 2 is a side view of the structure of the first embodiment of the image scanning system of the present invention.

FIG. 3 is a structural top view of the first embodiment of the image scanning system of the present invention.

FIG. 4 is a structural perspective view of the first embodiment of the image scanning system of the present invention.

Fig. 5 is a schematic diagram of the appearance of the first type of guiding element in Fig. 2 .

Fig. 6 is a schematic diagram of the appearance of the second type of guiding element in Fig. 2 .

FIG. 7 is a schematic view of the appearance of the guide element equipped with a damper in FIG. 2 .

FIG. 8 is a side view of the structure of the second embodiment of the image scanner of the present invention.

Please refer to FIG. 2 , which is a cross-sectional view along the scanning line direction of the first implementation of the image scanner of the present invention. The image scanner includes a housing 12, an upper cover 10, a scanning platform 23 disposed on the upper surface of the housing 12 and used as a supporting surface of the document to be scanned, guide elements 50, 50a disposed on both sides of the scanning platform protruding edges, The scanning module 40 fixed on the guide elements 50 and 50a, and the driving device 60 used to drive the scanning module 40 to move.

As shown in FIG. 4 , the scanning platform 23 has a flat surface for carrying documents to be scanned. The scanning platform 23 is preferably made of glass, but it can also be a transparent and light-permeable medium such as plastic. As shown in FIG. 2 , the scanning platform 23 has protruding ends 24, 24a on both sides, which are used to slide guide elements 50, 50a, so that the guiding elements 50, 50a can be placed on the scanning platform 23 along the protruding ends 24, 24a. Move freely. The scanning module 40 is fixed under the guide elements 50, 50a and keeps a certain distance from the scanning platform 23 to form a fixed depth of field during scanning.

As shown in FIG. 5 , a cross-sectional view of the clamp 51 of the guiding element 50 is shown. The guide elements 50, 50a include at least two corresponding clamps 51, 51a, and the cross-section of the clamps 51, 51a is roughly U-shaped, and the openings thereof are opposite to each other, and can just clamp the protruding ends 24, 51a of the scanning platform 23. 24a. As shown in Figure 5, several contact elements 52 are formed on the inner side of these clamps 51, 51a, and the contact surface of the contact elements 52 and the scanning platform 23 is a surface with a low friction number, for example, a layer of low friction is coated on a certain surface. Several materials, such as Teflon, etc., so that the guide elements 50, 50a can not only clamp the protruding ends 24, 24a, but also slide easily on the scanning platform 23.

The scanning module 40 is connected and fixed to the lower edges of the two fixtures 51 , 51 a and keeps a fixed distance from the scanning platform 23 . As a result, the scanning module 40 can move along the surface extension direction of the scanning platform 23 with the drive of the driving device 60 while maintaining a certain relative position with the scanning platform 23 through the support of the clamps 51 and 51 a.

In the embodiment shown in Figures 2, 3, and 4, the driving device 60 of the mobile scanning module 40 is directly arranged on the scanning module 40, so that the scanning module 40 can move along the longitudinal direction of the scanning platform 23. The driving device 60 includes a motor 61 arranged on the scanning module 40, a reduction gear set composed of a plurality of gears A62, B63, and C64 meshing with each other, and a tooth set at the bottom of the housing 12 and meshed with the reduction gear C64. Article 65.

Therefore, when the scanner is powered on, it will drive the motor 61 to rotate, which will drive the gear 62 to rotate, and the gear 62 will drive the gear 63 and the gear 64 to rotate. Since the gear 64 and the rack 65 are engaged with each other, and the rack 65 is fixed at the bottom of the housing 12 , when the gear 64 rotates, it relatively drives the scanning module 40 to move for scanning operation.

Since the motor 61 and the reduction gear sets 62, 63, 64 of the present invention are all directly arranged on the scanning module 40, and the rack 65 is fixed on the bottom of the housing 12 of the scanner, during installation, only the scanning module 40 It is enough that the gear C64 and the rack 65 are meshed, and the problem of adjustment can be omitted.

Certainly, the method for driving the scanning module 40 to move is not limited to the above-mentioned method of installing the driving device on the scanning module 40 , and other methods such as timing belts, rope transmission mechanisms, or other similar methods can be used.

Wherein, because the scanning module 40 of the present invention is fixed below the scanning platform 23 by the guide elements 50, 50a, the scanning module 40 takes the scanning platform 23 as the reference plane, and the reference plane of the document to be scanned is also the scanning platform 23, so by With this guide element 50, 50a, the moving direction of the document to be scanned and the scanning module 40 can be based on the scanning platform 23 reference plane. In this way, when the scanner is assembled, it is not necessary to wait for the conventional The reference planes of the scanning document and the scanning module 40 are different, and the reference planes of the two need to be adjusted, which can save the installation time of the user.

In addition, since the scanning module 40 is fixed below the scanning platform 23, the scanning module 40 can move relatively parallel to the scanning platform 23 during the scanning process, so as to achieve the purpose of maintaining a certain depth of field between the document to be scanned and the scanning module 40 , which can improve the control of depth of field and the quality of image distortion during scanning.

Please refer to FIG. 7 , which are respectively the second embodiment of the guide element 50a in the depth of field maintaining device. As shown in FIG. 7 , some components of this embodiment are the same as those of the first embodiment and will continue to use their labels. The difference between this embodiment and the first embodiment is that the clamp 51a arranged on one side of the scanning platform 23 is selected, A damper 53 is added, and this damper 53 has elasticity (for example: a spring or other elements with similar functions), and abuts against the side edge of the scanning platform 23 through one of the contact elements 52 to absorb the vibration of the scanning platform. The width error and the buffering of the torque generated when the scanning module 40 moves can avoid the vibration phenomenon that the scanning module 40 may generate during the moving process, so as to prevent the scanning module 40 from moving left and right and affect the scanning quality. A schematic plan view of the guiding element 50a is shown in FIG. 8 . The preferred position of the damper 53 is disposed in the fixture 51 a on the other side of the scanning module 40 relative to the driving device 60 .

The implementation state of the guiding element disclosed in the present invention is not limited to the style disclosed in the present invention, and the installation direction of the guiding element can also be changed, so that the scanning module can be fixed on the top of the bearing surface, and in addition The driving device used to drive the scanning module to move can also be replaced by other mechanical structures. In a word, as long as the scanning module can be fixed on the surface of the scanning platform and can guide the scanning module to The purpose of reciprocating movement with the scanning platform along a certain distance, no matter which type of guide element or driving device can be achieved according to the technology disclosed in the present invention.

Claims (9)

1. An image scanner, which includes a housing and a scanning platform with a flat surface as a bearing surface, characterized in that: the guide element is composed of several clamps and is slidably arranged on both sides of the scanning platform , and move along the longitudinal direction of the scanning platform; the scanning module is fixed on the guiding element, and includes a photoelectric conversion module to convert the image of the document to be scanned into a corresponding electrical signal, and a driving mechanism It is used to drive the scanning module to move along the longitudinal direction of the scanning platform. 2. The image scanner according to claim 1, further comprising an upper cover for flattening the document to be scanned on the scanning platform. 3. The image scanner according to claim 1, wherein the scanning platform has protruding edges at both ends in the scanning line direction. 4. The image scanner according to claim 3, wherein the cross-section of the clamp is substantially U-shaped, the openings of which are opposite to each other, and can just clamp the protruding edge of the scanning platform. 5. The image scanner according to claim 4, characterized in that: a contact element for contacting with the protruding edge of the scanning is provided inside the fixture. 6. The image scanner according to claim 5, wherein the contact surface of the contact member is a low-friction surface. 7. The image scanner according to claim 4, wherein a damper for buffering the torque generated by the movement of the scanning module can be provided inside the fixture. 8. The image scanner according to claim 7, wherein the damper is a spring. 9. The image scanner according to claim 1, characterized in that: the motor of the driving device is arranged on the scanning module; the reduction gear set for outputting the power of the motor is matched with the motor; a rack is fixed It is arranged on the housing and meshes with the reduction gear set.

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