KR101365007B1 - Line optical source module for maintaining focal length included x-ray image detector using optical switching readout - Google Patents

Abstract

The present invention relates to a line light source module for an X-ray image detector using an optical switching manner, comprising a light emitting diode (LED) array having a plurality of LEDs arranged therein; an optical film for diffusing and directing light outputted from the LED array; a glass substrate for converting the light directed by the optical film to generate a line beam of a pixel size using a slit formed in one surface; and a lens array for transferring the line beam outputted from the glass substrate to an X-ray sensor included in the X-ray image detector, wherein the glass substrate is laminated between the optical film and the lens array, and the thickness of the laminated glass substrate is based on the focal distance of the lens array.

Description

Line optical source module for maintaining focal length included X-ray image detector using optical switching readout

The present invention relates to a digital X-ray image detector, and more particularly, to a line light source module used in a digital X-ray image detector using an optical switching method and capable of securing a constant focal length.

In general, a medical or industrial digital X-ray image detector which photographs a body part or an object of a patient using X-ray transmission characteristics is widely used. Such a digital X-ray image detector uses a TFT (Thin Film Transistor) in a pixelated readout Photo Conductive Layer (PCL) (optical conductive layer) to obtain X-ray image information.

However, in the method of reading out x-ray image information using a TFT, noise is increased when the pixel size is small, so that it may be difficult to miniaturize the pixel while improving the resolution of the image . In order to solve such a problem, in recent years, a method of reading image information by using optical switching without using existing TFT switching has been developed.

FIG. 1 is a view for explaining a principle of reading X-ray image information using optical switching according to the related art.

Referring to FIG. 1, an X-ray image detector using a conventional optical switching method transmits an X-ray generated by an X-ray generator to an object or a human body to be photographed, .

In this case, as shown in FIG. 1A, when a voltage is applied across both the upper electrode 150 and the lower electrode 110 and X-rays are incident, a-Se, which is an X-ray conversion material, in the X-ray PCL. Electrons 101 and holes 102 are generated via the photoconductor layer 140 such as CZT (CdZnTe), CdTe, PbI2, HgI2PbO, BiI3, and the like. Electrons 101 and holes 102 are separated by an electric field formed by a voltage applied to both electrodes, holes move to the upper electrode, electrons move to the lower electrode, and a charge accumulation layer (CAL) ( 130).

Subsequently, as shown in FIG. 1B, the negative electrode corresponding to the upper electrode 150 to collect electrons from the readout PCL 120 in a state where the electrons 101 and the holes 102 are separated from each other is shown. When the electrode is converted to ground, the hole 102 of the upper electrode 150 is canceled by the grounded negative electrode, and the lower electrode 110 is formed by the hole 103 by the electrons collected in the CAL 130. As this is induced and offset, it is possible to cancel the internal electric field as a whole.

As shown in FIG. 1C, when light is irradiated from the lower electrode to the readout PCL 120 to read the electrons 101 accumulated in the CAL 130, the readout PCL 120 is irradiated with light. New electrons 104 and holes 105 are generated. In this case, the generated hole 105 disappears by being combined with the electrons 101 accumulated in the CAL 130, and reflects the image information at the output terminal of the readout PCL 120 from the electrons 104 corresponding to the number of the combined holes. The charge can be obtained.

In order to read the X-ray image information by the method shown in FIG. Done.

However, such a method requires a collimation lens, a cylindrical lens, a mirror, an optical component and a mount for supporting the same, and an optical axis must be aligned and fixed due to the straightness of the laser. There is a problem that the production is not easy due to such problems.

In addition, since the panel of the X-ray image detector is large in size depending on the application, one laser light source cannot be used, and multiple laser light sources must be used. Therefore, the line light source generated by each laser light source must be aligned in one column, and the two lines Where the light source meets, there is a problem that it is difficult to maintain the uniformity of the light output.

The present invention has been made to solve the above problems, and provides a line light source module for an X-ray image detector that can easily secure the optically sensitive focal length while using an LED array without using a laser diode will be.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

A line light source module for an X-ray image detector using a light switching method according to an embodiment of the present invention for solving the above problems, LED array array of a plurality of LED (Light Emitting Diode); An optical film to diffuse and go straight from the light output from the LED array; A glass substrate which converts light traveling straight by the optical film into a line beam having a pixel size by using a slit formed on one surface thereof; And a lens array configured to transfer a line beam output from the glass substrate to an X-ray sensor included in the X-ray image detector, wherein the glass substrate is stacked between the optical film and the lens array. The thickness of the glass substrate is based on the focal length of the lens array.

The glass substrate may be coated with a predetermined light absorber on one surface facing the optical film, and the slit may be formed on the surface on which the light absorber is coated.

At this time, the light that does not pass through the slit of the light going straight by the optical film is absorbed by the light absorber and the light passing through the slit may be converted into a line beam.

The slit corresponds to each of a plurality of LED elements constituting the LED array, and may be formed on the glass substrate in the same line as the LED elements.

The lens array may include a plurality of gradient index (GRIN) lenses.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the present invention by those skilled in the art. And can be understood and understood.

According to the present invention, it is possible to provide a line light source module for an X-ray image detector which can easily secure an optically sensitive focal length while using an LED array without using a laser diode.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
1 is a view for explaining the principle of reading the X-ray image information by using the optical switching according to the prior art.
2 is a diagram illustrating an example of a line light source module for an X-ray image detector using a light switching method according to an embodiment of the present invention.
3 is a diagram illustrating an example of a line light source module including a glass substrate in an X-ray image detector using an optical switching method according to an exemplary embodiment of the present invention.
4 is a view showing a characteristic that the line beam width is changed according to the distance between the optical film and the lens array in the X-ray image detector according to an embodiment of the present invention.
5 is a diagram illustrating a form in which the line light source module illustrated in FIGS. 2 and 3 is implemented. Specifically, FIG. 5 is a side view illustrating a cross section of the line light source module.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these specific details.

The present invention relates to a digital X-ray image detector, and more particularly, to a line light source module used in a digital X-ray image detector using an optical switching method and capable of securing a constant focal length.

2 is a diagram illustrating an example of a line light source module for an X-ray image detector using a light switching method according to an embodiment of the present invention.

Referring to FIG. 2, the X-ray image detector 200 using the light switching method includes a line light source module 210 for generating light having a predetermined wavelength and a line light source module for collecting image information by irradiated light. It consists of an X-ray sensor 220 located on the top of the 210.

The line light source module 210 according to the embodiment of the present invention is a module for generating light having a predetermined wavelength so that the X-ray sensor 220 collects an image signal, and the LED (Light Emitting Diode Array) array 211 , An optical film 213, a glass substrate 215, and a lens array 217. In this case, the LED array 211, the optical film 213, the glass substrate 215 on which the slits are formed, and the lens array 217 may be stacked in this order.

The LED array 211 is an LED panel and may include a plurality of LED elements 211b arranged in a line on a predetermined printed circuit board 211a. The line beam formed by the LED element corresponds to a plurality of pixels.

The optical film 213 may be composed of one or more optical films for improving light emission and linearity of light output from the LED array 211 and forming a line light source.

The glass substrate 215 is stacked between the optical film 213 and the lens array 217 to maintain the distance between the optical film 213 and the lens array 217 at a constant distance. The glass substrate 215 is for uniformizing the size of the line beam width and the resolution of the image information generated by the lime beam, which vary according to the distance between the lens array 217 and the optical film 215.

The glass substrate 215 may be designed to form a line beam by coating a predetermined absorber on one surface facing the optical film 215 and forming a slit. This will be described in more detail with reference to FIG. 3.

The lens array 217 is, for example, a GRIN (Gradient Index) lens array, and collects the line beam passing through the glass substrate 215 in the form of a line in the optical switching readout area (or readout PCL) of the X-ray sensor 220. Or focus.

The X-ray sensor 220 is a line-shaped X-ray sensor and converts an X-ray photographed image into a digital output, and includes an X-ray sensor for a digital X-ray image detector using an optical switching method. can do. Although not shown in FIG. 2, the upper electrode, the X-ray PCL, the CAL, the readout PCL, and the lower electrode may be included as described above with reference to FIG. 1.

As described above, the digital X-ray image detector using the optical switching method according to the embodiment of the present invention transmits the X-ray image information obtained by transmitting the X-ray generated by the X-ray generator to the object to be photographed X-ray It is incident on the surface of the sensor 220. The optical switching method can increase the absorption rate of X-rays by using a conductor that directly absorbs X-rays to generate electrons and holes, and can secure low noise and high Detective Quantum Efficiency (DQE).

However, the LED element included in the LED array 211 may have difficulty in using as a light switching readout line light (line light source) of the light switching readout X-ray sensor 220 due to a wide viewing angle (visibility).

Specifically, the characteristics of the line light source of the optical switching readout X-ray sensor 220 should have a line width of the pixel size, and the light intensity to be sufficient to read the charge generated by the X-rays should be ensured. In addition, the uniformity of the line light source (output intensity of the line light source) should be ensured for each position. For example, for a blue LED with a wavelength of 450 nm, the light intensity is sufficient, but the light intensity of the blue LED may not be sufficient for use as a line light source (pixel line) having a beam width of pixel size because of the large device area and viewing angle. have.

In addition, since the size of each device (LED) included in the LED array 211 is large, it may be difficult to ensure the uniformity of the light intensity when arranged in a line.

In addition, the size of the line beam width and the resolution and uniformity of the image information generated by the lime beam are affected by the distance between the lens array 217 and the optical film 215 depending on the focal length of the lens array 217 and both. It can be difficult to maintain a certain distance between them.

Therefore, the X-ray image detector according to the embodiment of the present invention is a glass substrate laminated in order to ensure the size of the lime beam width and the uniformity of the light intensity incident on the lens array 217 and further obtain uniform image information. We propose a Lime light source module.

3 is a side perspective view of a line light source module including a glass substrate in an X-ray image detector using a light switching method according to an embodiment of the present invention.

As shown in FIG. 3, the LED array 310, the optical film 320, the glass substrate 330, the lens array 340, and the X-ray sensor 350 constituting the line light source module are shown in FIG. 2. Since the LED array 211, the optical film 213, the glass substrate 215, the lens array 217, and the X-ray sensor 220 correspond to the above-described elements, the same description for each component will be omitted.

Referring to FIG. 3, the glass substrate 330 included in the line light source module 300 according to the embodiment of the present invention is coated with an absorber 331 that absorbs light on one surface facing the optical film 320. A slit 333 corresponding to the plurality of LED elements 311 constituting the LED array 310 is formed on one surface coated with the absorber 331. Preferably, by forming the slit at the pixel size, the pixel beam may be designed to irradiate the lens array 340 through the glass substrate 330.

The absorber 331 absorbs the scattered light that may occur while passing through the optical system, and the beams that do not pass through the slit are configured to be absorbed in the remaining absorbing region except for the slit so that the light applied to the lens array 217 is line beam. It can be defined.

In this case, the slits formed on the glass substrate 330 may be formed in a line with the LED element 311, and the length of the slits may be increased or decreased according to the number of LED elements.

In addition, the thickness d of the glass substrate 330 is designed based on the focal length of the lens array 340, thereby ensuring accurate focal length of the lens and maintaining a uniform line width of the line light source. This is based on the line beam width depending on the distance between the optical film 320 for outputting light and the lens array 340 for outputting image information using the output light as an incident angle and the focal length of the lenses constituting the lens array 340. This is because the size and resolution of the image degree generated by the lime beam may vary.

4 is a view showing a characteristic that the line beam width is changed according to the distance between the optical film and the lens array in the X-ray image detector according to an embodiment of the present invention.

Referring to FIG. 4, it can be seen that the line beam line width formed on the surface of the readout photoconductor of the X-ray image detector changes according to the distance between the optical film and the lens array. For example, if the distance between the optical film and the lens array is separated by more than the reference value ((a), (e) position), the line beam width becomes wider than the reference value, the beam accuracy is lowered, while the distance between the optical film and the lens array is measured It can be seen that the implementation of the focal length similar to the (c) position increases the accuracy of the beam line width.

The size and accuracy of the line beam width may affect the accuracy and uniformity of the image information acquired by the X-ray sensor 350.

5 is a diagram illustrating a form in which the line light source module illustrated in FIGS. 2 and 3 is implemented. Specifically, FIG. 5 is a side view illustrating a cross section of the line light source module.

Referring to FIG. 5, the line light source module 500 according to an embodiment of the present invention may include an LED array printed circuit board (PCB) 501 and a LED array PCB in which a plurality of LED elements are arranged to output light having a predetermined wavelength. The optical film 502, the glass substrate 503, and the lens array 504 may be spaced apart from the 501 by a predetermined distance and stacked to form light output by the LED elements as a line beam.

As described above, the glass substrate 503 is provided with a slit for transmitting light output from the LED element in a state in which an absorber for absorbing light is coated on one surface corresponding to the LED array. In addition, by designing the thickness d of the glass substrate 503 based on the distance between the optical film and the lens array according to the lens focal length as described above with reference to FIG. 4, an accurate lens focal length can be ensured. In addition, by inserting a solid transparent body called a glass substrate 503 between the optical film 502 and the lens array 504, it is possible to solve the problem of the line width uniformity of the line light source, which may occur due to the focal length mismatch at every lens position. have.

Further, by increasing the thickness of the absorber coated on the glass substrate 330 to a predetermined value or more, when using a thin slit, it is possible to reduce the instability of the line light source line width due to the vibration of the slit that may occur when scanning the object.

As such, the line light source module using the glass substrate having the slit according to the embodiment of the present invention includes a plurality of prisms (prism patterns) for converting side light to front light, such as a prism sheet. By using the prepared optical film, the light condensing property can be increased and the brightness can be increased.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are not intended to limit the technical idea of the present invention but to explain, and the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents thereof should be construed as being included in the scope of the present invention.

Claims (5)

A line light source module for an X-ray image detector using a light switching method,
An LED array in which a plurality of light emitting diodes (LEDs) are arranged;
An optical film to diffuse and go straight from the light output from the LED array;
A glass substrate which converts light traveling straight by the optical film into a line beam having a pixel size by using a slit formed on one surface thereof; And
It includes a lens array for transmitting the line beam output from the glass substrate to the X-ray sensor included in the X-ray image detector,
The glass substrate,
And a thickness of the laminated glass substrate based on the focal length of the lens array. The method of claim 1,
The glass substrate,
A predetermined light absorber is coated on one surface facing the optical film, and the slit is formed on the surface on which the light absorber is coated. 3. The method of claim 2,
Light that does not pass through the slit among the light going straight by the optical film is absorbed by the light absorber and the light passing through the slit is converted into a line beam. 3. The method according to claim 1 or 2,
The slit
A line light source module is formed on the glass substrate and collinear with a plurality of LED elements constituting the LED array. The method of claim 1,
Wherein the lens array comprises:
A line light source module, comprising a plurality of GRIN (Gradient Index) lenses.

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