阅读说明：本技术 一种影像扫描设备的光束调整装置 (Light beam adjusting device of image scanning equipment ) 是由 周红武 胡安元 吴征巍 曹强荣 卜荣君 于 2019-09-25 设计创作，主要内容包括：本发明公开了一种影像扫描设备的光束调整装置,其能够减小余晖效应对空间分辨率的影响。一种影像扫描设备的光束调整装置,包括激光光源、光源基座、固定座、准直透镜以及聚焦透镜,所述激光光源安装于所述光源基座上,所述准直透镜及所述聚焦透镜设置于所述固定座上；所述光束调整装置还包括转动座,所述光源基座设置于所述转动座上,所述转动座可转动的设置于所述固定座上,且所述转动座的转动轴心线与所述激光光源的光束出射方向一致；所述激光光源具有快轴和慢轴,当所述光束调整装置在工作状态时,所述激光光源的快轴方向与影像扫描设备的行扫描方向一致,所述激光光源的慢轴方向与影像扫描设备的列扫描方向一致。(The invention discloses a light beam adjusting device of an image scanning device, which can reduce the influence of afterglow effect on spatial resolution. A light beam adjusting device of an image scanning device comprises a laser light source, a light source base, a fixed base, a collimating lens and a focusing lens, wherein the laser light source is arranged on the light source base; the light beam adjusting device also comprises a rotating seat, the light source base is arranged on the rotating seat, the rotating seat is rotatably arranged on the fixed seat, and the rotating axis of the rotating seat is consistent with the light beam emitting direction of the laser light source; when the light beam adjusting device is in a working state, the fast axis direction of the laser light source is consistent with the row scanning direction of the image scanning equipment, and the slow axis direction of the laser light source is consistent with the column scanning direction of the image scanning equipment.)

1. A light beam adjusting device of an image scanning device comprises a laser light source, a light source base, a fixed base, a collimating lens and a focusing lens, wherein the laser light source is arranged on the light source base; the method is characterized in that: the light beam adjusting device also comprises a rotating seat, the light source base is arranged on the rotating seat, the rotating seat is rotatably arranged on the fixed seat, and the rotating axis of the rotating seat is consistent with the light beam emitting direction of the laser light source; when the light beam adjusting device is in a working state, the fast axis direction of the laser light source is consistent with the row scanning direction of the image scanning equipment, and the slow axis direction of the laser light source is consistent with the column scanning direction of the image scanning equipment.

2. A beam steering arrangement according to claim 1, wherein: the light source base is movably arranged on the rotating seat along the light beam emergent direction.

3. A beam steering arrangement according to claim 2, wherein: the light source base is connected to the rotating seat through threads.

4. A beam steering arrangement according to claim 3, wherein: the light source base can be movably inserted in the rotating base along the light beam emergent direction, external threads are arranged on the outer wall of the light source base, and internal threads matched with the external threads are arranged on the inner wall of the rotating base.

5. a beam steering arrangement according to claim 1, wherein: the light beam adjusting device further comprises a fastening screw for locking the rotating seat.

6. A beam steering arrangement according to claim 1, wherein: the collimating lens and the focusing lens are movably arranged on the fixed seat along the direction vertical to the emergent direction of the light beam.

7. A beam modification apparatus as defined in claim 6, wherein: the light beam adjusting device further comprises a lens mounting seat, the collimating lens and the focusing lens are arranged on the fixed seat through the lens mounting seat, the collimating lens is fixedly arranged in the fixed seat, and the lens mounting seat can be movably inserted in the fixed seat along the direction vertical to the light beam emergent direction.

8. A beam steering arrangement according to claim 7, wherein: the light beam adjusting device further comprises a sleeve, the sleeve is movably arranged in the lens mounting seat along the light beam emergent direction, and the focusing lens is fixedly arranged in the sleeve.

9. A beam modification apparatus as defined in claim 8, wherein: the outer wall of the sleeve is provided with an external thread, and the inner wall of the lens mounting seat is provided with an internal thread matched with the external thread.

10. a beam steering arrangement according to claim 7, wherein: and the fixed seat is internally provided with an adjusting screw for pushing the lens mounting seat to move and a spring for resetting the lens mounting seat.

Technical Field

the invention relates to the field of computer X-ray photography imaging, in particular to a light beam adjusting device of image scanning equipment.

background

Computed-Radiography (CR) has been widely used in the medical health field, in which X-rays are irradiated onto an image plate containing light-activated fluorescent powder through an object, and a frame of latent image (LatentImage) is generated and stored in the image plate. When laser light with a certain wavelength (600-700nm) is used for irradiation, the image plate excites fluorescence with a specific wavelength (350-450nm), the energy distribution characteristic of the fluorescence is completely related to the shape of a latent image, and the fluorescence is collected, converted into an electric signal and digitized, so that the latent image is converted into a two-dimensional digital image which can be stored and transmitted.

The imaging plate can be used for taking pictures and imaging teeth by utilizing the latent image characteristic of the imaging plate, and compared with the traditional film imaging method, the CR technology has the advantages of high imaging speed, wide display dynamic range, reusability of a film and the like. An optical scanning system, which is one of the core components, is related to the speed of the whole imaging process and the image quality, and the light source and the focusing lens assembly of the optical system directly influence the quality of a light spot finally used for imaging.

Spatial resolution, i.e., the ability to discriminate the size of a spatial object, is an important parameter in measuring CR, and represents the ability of an imaging system to discriminate objects that are close to each other, typically measured by the number of pairs that can be identified within 1mm (Lp/mm). A black line and a white line are generally used as a line pair as shown in fig. 1, and a larger number of line pairs per unit distance indicates a higher spatial resolution of the system. Factors that affect CR spatial resolution include: the composition and thickness of the IP (image plate) plate, the size of the laser spot, the size of the scattered light of the IP plate, the signal collection efficiency, and the influence of afterglow.

Disclosure of Invention

In view of the above problems, it is an object of the present invention to provide a beam adjusting apparatus of an image scanning device, which can reduce the influence of afterglow effect on spatial resolution.

In order to achieve the purpose, the invention adopts the technical scheme that:

A light beam adjusting device of an image scanning device comprises a laser light source, a light source base, a fixed base, a collimating lens and a focusing lens, wherein the laser light source is arranged on the light source base; the light beam adjusting device also comprises a rotating seat, the light source base is arranged on the rotating seat, the rotating seat is rotatably arranged on the fixed seat, and the rotating axis of the rotating seat is consistent with the light beam emitting direction of the laser light source; when the light beam adjusting device is in a working state, the fast axis direction of the laser light source is consistent with the row scanning direction of the image scanning equipment, and the slow axis direction of the laser light source is consistent with the column scanning direction of the image scanning equipment.

Preferably, the light source base is movably disposed on the rotating base in the light beam emitting direction.

more preferably, the light source base is connected to the rotating base by a screw.

Furthermore, the light source base can be movably inserted in the rotating seat along the light beam emergent direction, external threads are arranged on the outer wall of the light source base, and internal threads matched with the external threads are arranged on the inner wall of the rotating seat.

Preferably, the light beam adjusting apparatus further includes a fastening screw for locking the rotary base.

Preferably, the collimating lens and the focusing lens are movably disposed on the fixing base along a direction perpendicular to the light beam emitting direction.

More preferably, the light beam adjusting device further includes a lens mounting seat, the collimating lens and the focusing lens are disposed on the fixing seat through the lens mounting seat, the collimating lens is fixedly disposed in the fixing seat, and the lens mounting seat is movably inserted in the fixing seat along a direction perpendicular to the light beam emitting direction.

Further, the light beam adjusting device further comprises a sleeve, the sleeve is movably arranged in the lens mounting seat along the light beam emergent direction, and the focusing lens is fixedly arranged in the sleeve.

Furthermore, the outer wall of the sleeve is provided with an external thread, and the inner wall of the lens mounting seat is provided with an internal thread matched with the external thread.

Furthermore, the fixing seat is provided with an adjusting screw for pushing the lens mounting seat to move and a spring for resetting the lens mounting seat.

by adopting the technical scheme, compared with the prior art, the invention has the following advantages:

The light beam adjusting device can adjust the fast axis direction of the light spot formed by the laser light source to be parallel to the line scanning direction of the image scanning equipment, and the slow axis direction of the light spot to be parallel to the column scanning direction of the image scanning equipment, so that the size of the light spot in the scanning direction is reduced, the effect of afterglow is reduced, the influence of the afterglow effect on the spatial resolution can be reduced, and the scanning spatial resolution is further improved.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a light beam adjusting apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic view of a line-to-card;

FIG. 3 is a schematic view of a scanning optical path of an image scanning apparatus according to an embodiment of the present invention;

FIG. 4 is a schematic view showing a larger spot in the scanning direction;

FIG. 5 is a schematic view showing a small spot in the scanning direction;

Fig. 6 is a far-field schematic diagram of a laser light source according to an embodiment of the invention.

In the above-described figures of the drawings,

1. A laser light source; 2. a light source base; 3. a diaphragm; 4. a rotating seat; 5. a fixed seat; 6. a collimating lens; 7. a focusing lens; 8. a sleeve; 9. a lens mount; 10. an adjusting screw; 11. fastening screws; 12. a pentaprism.

Detailed Description

preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the invention may be more readily understood by those skilled in the art. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The present embodiment provides an image scanning apparatus based on an X-ray photographing technology, and more particularly, to a light beam adjusting device of an image scanning apparatus. Referring to fig. 1, the light beam adjusting apparatus includes a laser light source 1, a light source base 2, a fixing base 5, a collimating lens 6, and a focusing lens 7. The laser light source 1 is specifically a semiconductor laser, and is fixedly mounted on the light source base 2. A diaphragm 3 is formed on the light source base 2. The light source base 2, the collimating lens 6 and the focusing lens 7 are disposed on the fixing base 5, which will be described in detail below. The light beam adjusting device further comprises a rotating seat 4, the light source base 2 is arranged on the rotating seat 4, the rotating seat 4 is rotatably arranged on the fixed seat 5, and the rotating axis of the rotating seat 4 is consistent with the light beam emitting direction of the laser light source 1 (more preferably, the rotating axis of the rotating seat 4 is coincident with the optical axis of the laser light source 1). When the light beam adjusting device is in a working state, the direction of the fast axis of the laser light source 1 is consistent with the row scanning direction of the image scanning device, and the direction of the slow axis of the laser light source 1 is consistent with the column scanning direction of the image scanning device.

The light beam adjusting device in the embodiment can reduce the size of light spots in the scanning direction and reduce the effect of afterglow, so that the scanning resolution is improved, and the specific principle is described as follows. Spatial resolution, the ability to discriminate the size of a spatial object, represents the ability of the imaging system to resolve objects that are close to each other, and is typically measured by the number of lines that can be identified within 1mm (Lp/mm). A black line and a white line are usually used as a line pair, and as shown in fig. 2, the larger number of line pairs that can be resolved per unit distance indicates the higher spatial resolution of the system.

factors that affect spatial resolution include: the composition and thickness of the image plate (image plate), the size of the laser spot, the size of the scattered light of the image plate, the signal collection efficiency, and the influence of afterglow. Where the size of the laser spot has the highest weight on the spatial resolution. For the flying spot scanning optical system, the most common means for improving the spatial resolution of the system is to reduce the size of the laser focusing spot, the general flying spot scanning optical path is shown in fig. 3, and the high-performance motor drives the pentaprism 12 to rotate at high speed, so as to realize the high-speed rotation (referred to as the line scanning direction herein) of the laser focusing spot. The stepping motor drives the image plate to move longitudinally (referred to as column scanning direction), and the servo motor and the stepping motor cooperate to realize two-dimensional scanning of the image plate.

The size of the focusing point is mainly determined by the size of the light emitting point of the laser light source 1, the magnification of the optical system, and the optical diffraction limit of the system. When the above parameters are predetermined, it means that the size of the focused spot cannot be changed. For the flying-spot type image scanning apparatus, the requirements for the size of the light spot in the row scanning direction and the column scanning direction are different due to the afterglow effect of the fluorescence excitation of the image panel. As shown in fig. 4, the two points O1 and O2 are two points that are scanned and sampled continuously, and there is no space left between O1 and O2 in consideration of design difficulty and video board operation speed. Meanwhile, when the image panel is designed, in order to reduce the effect of afterglow, the sampling time of two points from O1 to O2 needs to be controlled to be longer than the afterglow time (microsecond level) of the image panel. This only ensures that the afterglow at the center position of O1 does not affect the data acquisition at the center point of O2, but the afterglow at other positions of O1 can cover the effective area of O2. Even if the sampling time interval of two points O1 to O2 is increased, the afterglow effect of the picture panel cannot be completely avoided. However, if the light spot in the scanning direction is decreased, as shown in fig. 5 below, the afterglow effect of the image panel can be completely avoided by appropriately increasing the sampling time interval of two points O1 to O2. However, reducing the size of the spot results in a reduced depth of focus of the entire CR system, which is more sensitive to optical system tolerances and, at the same time, causes significant disadvantages to the mechanical design.

Based on this, in the case that the size of the light emitting point of the laser light source 1 and the magnification of the optical system are determined, the light beam adjusting apparatus provided in this embodiment can reduce the size of the light spot in the scanning direction by adjusting the direction of the fast and slow axes of the laser light source 1, and then increase the sampling interval, thereby effectively avoiding the afterglow effect of the image panel. The spot size in the line scanning direction can be changed by adjusting the fast and slow axis direction of the laser light source 1 because the spot size in the fast and slow axis direction of the laser light source 1 is different. For the single-mode semiconductor laser employed in the present embodiment, as shown in fig. 6 below, the divergence angle in the fast axis direction F is large, but the light emission point is small (the beam waist 11 size is small); the slow axis direction S has a small divergence angle but a large light emitting point (a large beam waist 12 size). The beam waist 11 (radius) in the fast axis direction F is 0.5um, the beam waist 12 (radius) in the slow axis direction S is 0.75um, and the slow axis spot size is 1.5 times the fast axis spot size through optical system amplification. The fast axis direction F of the light spot can be adjusted to be parallel to the row scanning direction by rotating the rotating seat 4 by a certain angle, and the slow axis direction S is parallel to the column scanning direction, so that the size of the light spot in the scanning direction can be reduced, and the effect of afterglow is reduced. Meanwhile, due to the problem of astigmatism of the semiconductor laser, beam waist positions in two directions of a fast axis and a slow axis are different, and the size of a light spot in the fast axis direction is used as a preferential adjustment object, so that the size of the light spot in the scanning direction can be further reduced.

Specifically, at least the lower end portion of the rotating base 4 is rotatably inserted into the fixing base 5, and the rotating base can rotate around the optical axis of the laser beam relative to the fixing base 5, so as to adjust the fast axis direction and the slow axis direction of the laser light source 1. The beam adjusting apparatus further comprises a fastening screw 11 for locking the rotary base 4. The fastening screw 11 is specifically arranged on the fixed seat 5, and when the fastening screw is screwed down, the rotating seat 4 is locked and can not rotate; when the rotating seat is loosened, the rotating seat 4 can rotate relative to the fixed seat 5.

The light source base 2 is movably disposed on the rotary base 4 in a light beam emitting direction (parallel to or coincident with the optical axis). Specifically, the light source base 2 is connected to the rotating base 4 by a screw, and the light source base 2 is rotated and can be moved relative to the rotating base 4 along the optical axis at the same time by the screw, thereby adjusting the distance between the laser light source 1 and the collimating lens 6. The light source base 2 can be movably inserted into the rotating base 4 along the light beam emitting direction, an external thread is arranged on the outer wall of the light source base 2, and an internal thread matched with the external thread is arranged on the inner wall of the rotating base 4.

The collimator lens 6 and the focusing lens 7 are movably disposed on the fixing base 5 in a direction perpendicular to the light beam emitting direction. Specifically, the light beam adjusting device further includes a sleeve 8 and a lens mounting seat 9, the collimating lens 6 and the focusing lens 7 are movably disposed on the fixing seat 5 along a direction perpendicular to the optical axis through the lens mounting seat 9, and the focusing lens 7 is specifically disposed on the lens mounting seat 9 through the sleeve 8 and can move along the optical axis relative to the collimating lens 6. Collimating lens 6 is fixed to be set up in the upper end of lens mount 9, and focusing lens 7 is fixed to be set up in the lower tip of sleeve 8, and sleeve 8 inserts and locates in lens mount 9, and lens mount 9 inserts and locates in fixing base 5 and can follow the relative fixing base 5 of the direction perpendicular to the optical axis and move, is provided with a plurality of wedge blocks in the fixing base 5 for cooperate lens mount 9 and the assembly of fixing base 5 and prevent that lens mount 9 breaks away from fixing base 5.

an adjusting screw 10 for pushing the lens mounting seat 9 to move and a spring for resetting the lens mounting seat 9 are arranged in the fixed seat 5. In this embodiment, at least two adjusting screws 10 are provided and are perpendicular to each other, so that the lens mount 9 can be pushed in two dimensions to move, and the right and left and front and rear adjustment can be performed on the collimator lens 6 and the focus lens 7. Each adjusting screw 10 and one spring correspond to each other and are located on opposite sides of the lens mount 9. The adjusting screw 10 horizontally penetrates through the fixing seat 5, and the top end of the adjusting screw is fixedly arranged on the jackscrew steel column.

the sleeve 8 can be movably inserted into the lens mounting seat 9 along the light beam emitting direction, the sleeve 8 and the lens mounting seat 9 are connected in a threaded fit mode, when the sleeve 8 is rotated, the sleeve 8 moves up and down along an optical axis relative to the lens mounting seat 9 under the action of threads, and therefore the distance between the collimating lens 6 and the focusing lens 7 is adjusted, and the distance between the focusing lens 7 and a fixed focal plane is achieved. Specifically, an external thread is provided on the outer wall of the sleeve 8, and an internal thread matched with the external thread is provided on the inner wall of the lens mount 9.

the adjusting method of the light beam adjusting device comprises the following steps:

Rotating the light source base 2, and adjusting the distance between the laser light source 1 and the collimating lens 6;

Screwing an adjusting screw 10 in the fixed seat 5 to adjust the position of the collimating lens 6, thereby realizing the directional adjustment of the collimated light beam;

Rotating the sleeve 8, adjusting the distance between the focusing lens 7 and the fixed focal plane, and realizing the adjustment of a focusing light path;

Loosening the fastening screw 11, rotating the rotating seat 4, and adjusting the fast axis direction of the light spot to be consistent with the line scanning direction of the image plate, and the slow axis direction of the light spot to be consistent with the row scanning direction of the image plate;

the fastening screw 11 is fixed.

The light beam adjusting device can be used for carrying out collimation debugging of a light path, debugging of directivity of the light path, debugging of a focusing light path and debugging of the direction of a fast and slow axis of a light spot, is integrated with multifunctional light path debugging, and has the functions of coarse adjustment and fine adjustment of the size of the light spot by decoupling the collimation light path and the focusing light path.

The light beam adjusting device adjusts the fast axis direction of the light spots to be parallel to the row scanning direction, and the slow axis direction of the light spots to be parallel to the column scanning direction, so that the size of the light spots in the scanning direction can be reduced, and the effect of afterglow is reduced. Meanwhile, due to the astigmatic action of the semiconductor laser, the focal positions of the fast axis and the slow axis are different, and the size of the light spot in the fast axis direction is taken as a preferential adjustment object, so that the size of the light spot in the scanning direction can be further reduced.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and are preferred embodiments, which are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.