X-ray imaging system and machine head thereof

Abstract

The invention discloses an X-ray imaging system and a machine head thereof. The machine head comprises a bulb tube and a beam limiting device. The beam limiting device is provided with an X-ray limiting device, a reflecting part, an image projection device and an adjusting device, the image projection device can project imaging light, and the imaging light is reflected to the X-ray limiting channel by the reflecting part and penetrates out of the beam limiting device through the X-ray limiting channel to form an image. The image projection device replaces a traditional LED light source, and because the image projection device can form an image, the image formed by the image projection device can comprise a light field used for representing an irradiation area of X rays and light field additional information used for displaying medical auxiliary information in the light field. The light field is imaged by the image projection device and is higher in definition. The light field additional information is beneficial for doctors to know more information during medical operation. The adjusting device is used for adjusting the emitting direction of imaging light of the image projection device so that the light field projected by the image projection device can coincide with the irradiation area of the X-rays.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to the head structure of an X-ray imaging system. Background Art

[0002] In X-ray imaging systems, such as radiation DR equipment, a beam limiter component is configured on the head to control the range of the emitted X-rays (for example, this can be achieved through an openable lead window), and the soft ray components are filtered out by an additional copper (or aluminum) filter inside the beam limiter to reduce radiation damage to the human body. At the same time, in order to show the doctor the actual irradiation range of the X-rays, an LED light source is configured in the traditional beam limiter. The LED light source forms a light field under the action of the beam limiter, and the light field coincides with the irradiation field (the X-rays coming out of the beam limiter). In addition, in order to indicate the center of the light field, the current beam limiter adopts a solution of attaching a thin cross light-blocking strip on the light window (a transparent baffle at the light outlet of the beam limiter) to block the light and produce a cross shadow in the middle of the light field.

[0003] However, in clinical practice, the light field formed by this LED light source can only display the size of the area, which is a single function. Moreover, the crosshairs at the center of the light field are created by occlusion, and the width of this crosshairs varies with the SID (source-image distance). Summary of the Invention

[0004] The present application provides an X-ray imaging system and a head thereof to demonstrate a structure in which an image projection device is used instead of an LED light source to form a light field.

[0005] According to one aspect of the present application, an embodiment provides a head of an X-ray imaging system, comprising:

[0006] a tube, the tube being used to generate an X-ray source and emit X-rays;

[0007] and a beam limiter, the beam limiter comprising an X-ray limiting device, a reflector, an image projection device, and an adjustment device, the X-ray limiting device forming an X-ray limiting channel, the X-rays emitted by the X-ray source passing through the X-ray limiting channel and exiting the beam limiter to be emitted toward the object to be detected;

[0008] The image projection device is capable of imaging light, the imaging light being reflected by the reflective member to the X-ray limiting channel and passing through the beam limiter through the X-ray limiting channel to form an image, the image including a light field for representing an irradiation area of ​​the X-ray and light field additional information for displaying medical auxiliary information in the light field;

[0009] The image projection device is mounted on the adjustment device, and the adjustment device is used to adjust the emission direction of the imaging light of the image projection device so that the light field formed by the image projection device can be kept coincident with the irradiation area of ​​the X-ray.

[0010] In one embodiment, the reflector reflects the imaging light to the X-ray limiting channel, and a mirror image virtual light source of the imaging light relative to the virtual light source formed by the image projection device on the reflector coincides with the focus of the tube.

[0011] In one embodiment, the reflector is arranged on the propagation path of the X-ray, and the reflector is made of a material that can allow the X-ray to pass through. The side of the reflector facing the X-ray limiting channel is a reflective surface, and the reflective surface is arranged at an angle. The image projection device is arranged on the side of the reflector, and the imaging light of the image projection device is projected toward the reflective surface.

[0012] In one embodiment, the opening angle β corresponding to the short side of the image in the image projection device is greater than or equal to twice the tube target angle of the tube.

[0013] In one embodiment, the projection ratio of the image projection device is less than or equal to 1.2.

[0014] In one embodiment, the light source edge contrast of the edge of the image projected by the image projection device is greater than 4.

[0015] In one embodiment, the diameter of the virtual light source formed by the lens assembly is less than or equal to 4.5 mm.

[0016] In one embodiment, the additional light field information includes at least one of light field size, positioning marker line, patient information, exposure parameters, cross center line, ionization chamber position and small body positioning picture.

[0017] In one embodiment, the image includes a picture and / or a video.

[0018] In one embodiment, the adjustment device has an adjustment freedom in at least one direction to adjust the emission direction of the imaging light of the image projection device.

[0019] In one embodiment, the image projection device has a light source assembly with multiple colors and a lens assembly for imaging. The illumination light emitted by the light source assembly is transmitted through the lens assembly to form the imaging light.

[0020] According to one aspect of the present application, an embodiment provides a head of an X-ray imaging system, comprising:

[0021] a tube having an X-ray source for emitting X-rays;

[0022] and a beam limiter, the beam limiter comprising an X-ray limiting device and an image projection device, the X-ray limiting device forming an X-ray limiting channel, the X-rays emitted by the X-ray source passing through the beam limiter through the X-ray limiting channel to be emitted toward the object to be detected;

[0023] The image projection device can project imaging light, and the imaging light passes through the beam limiter through the X-ray limiting channel to form an image. The image includes a light field for displaying the irradiation area of ​​the X-ray.

[0024] According to one aspect of the present application, an embodiment provides an X-ray imaging system, comprising a head as described in any one of the above items and a detector for receiving X-rays emitted by the head.

[0025] The head of the X-ray imaging system according to the above-described embodiment includes a tube and a beam limiter. The beam limiter includes an X-ray limiting device, a reflector, an image projection device, and an adjustment device. The image projection device is capable of projecting imaging light, which is reflected by the reflector into an X-ray limiting channel and passes through the beam limiter through the X-ray limiting channel to form an image. The image projection device replaces a traditional LED light source. Since it can form an image itself, the image it forms can include a light field representing the X-ray irradiation area and additional light field information for displaying auxiliary medical information within the light field. The light field is formed by the image projection device itself, resulting in higher resolution. This additional light field information helps doctors obtain more information during medical procedures. The image projection device is also mounted on an adjustment device, which is used to adjust the emission direction of the imaging light from the image projection device so that the light field projected by the image projection device coincides with the X-ray irradiation area, thereby forming a light field that meets regulatory requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the machine head projecting X-rays toward the bed surface below in one embodiment of the present application;

[0027] Figure 2 This is a schematic diagram of the machine head projecting X-rays toward a side column in one embodiment of the present application;

[0028] Figure 3 This is a schematic cross-sectional view of the nose of an embodiment of the present application;

[0029] Figure 4 A schematic diagram of the overlap of a virtual light source of a lens assembly relative to a mirror image formed by a reflector and a focus of a bulb in one embodiment of the present application;

[0030] Figure 5A schematic diagram of the XYZ axes in an image projection device according to an embodiment of the present application;

[0031] Figure 6 and 7 This is a schematic diagram of a light field formed by an image projection device in an embodiment of the present application, where the light field shows its size.

[0032] Figure 8 Schematic diagram of a light field formed by an image projection device in one embodiment of the present application. In this case, the light field displays patient identification information, imaging site, and exposure parameters.

[0033] Figure 9 Schematic diagram of the light field formed by the image projection device in one embodiment of the present application. At this time, the light field is Figure 7 The ionization chamber position is also shown on the basis;

[0034] Figure 10 Schematic diagram of the light field formed by the image projection device in one embodiment of the present application. At this time, the light field is Figure 7 On the basis of the above, the positioning guidance pattern is also displayed;

[0035] Figure 11 Schematic diagram of an angle α corresponding to a long side and an angle β corresponding to a short side of an image projection device in one embodiment of the present application;

[0036] Figure 12 Schematic diagram of an image projection device forming a penumbra under an X-ray restriction channel in one embodiment of the present application. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0038] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0039] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0040] The present application provides an X-ray imaging system, which emits X-rays to irradiate a patient to obtain an image of a certain part of the patient, thereby helping doctors to diagnose and treat the patient.

[0041] In some embodiments, the X-ray imaging system includes a handpiece for emitting X-rays and irradiating a patient, and a detector (e.g., a flat-panel detector) for receiving the X-rays emitted by the handpiece. The patient can be a human, an animal, or another subject. Of course, the X-ray imaging system may also include other components, such as a handpiece support component, etc. These components can be described in detail in the prior art and will not be further elaborated here.

[0042] The handpiece can be used to irradiate the patient in various existing ways, for example, please refer to Figure 1 In one embodiment, the handpiece 100 is arranged above the bed surface 200, and the patient lies on the bed surface 200, and the handpiece 100 can irradiate the patient from top to bottom. Alternatively, please refer to Figure 2 In one embodiment, the handpiece 100 may be disposed on a side of the column 300 , and the patient stands between the column 300 and the handpiece 100 , and the handpiece 100 irradiates the patient from the side.

[0043] The handpiece 100 is used to emit X-rays and allow the X-rays to irradiate the patient at a set angle. Figure 3 and 4In some embodiments, the head 100 includes a tube 110 and a beam limiter 120. The tube 110 is used to generate an X-ray source and emit X-rays. The X-rays emitted from the tube 110 are emitted at a certain angle (tube target angle) and enter the cavity of the beam limiter 120. The beam limiter 120 has an X-ray limiting device 121, and the X-ray limiting device 121 forms an X-ray limiting channel 1211. The X-rays emitted by the X-ray source pass through the beam limiter 120 through the X-ray limiting channel 1211 to be emitted to the object to be inspected. The function of the X-ray limiting device 121 is to limit the range and area of ​​the X-ray emission beam limiter 120. For example, a commonly used lead window can be used but is not limited to it. Please refer to Figure 4 In some embodiments, the X-ray limiting channel 1211 of the X-ray limiting device 121 is a light exit port, from which some X-rays can be emitted, while some X-rays are blocked by the X-ray limiting device 121 and cannot be emitted, thereby forming an actual X-ray irradiation area (i.e., the X-ray light field) that can irradiate the patient.

[0044] Also, please refer to Figure 3 and 4 In some embodiments, the beam limiter 120 may further include a reflector 122 and an image projection device 123. The image projection device 123 is a device capable of projecting images and / or videos, and may be, for example, a common projector. The image projection device 123 includes a light source component capable of emitting multiple colors and a lens component 1231 for imaging (e.g., Figure 5 As shown). The light source assembly may be, for example, but not limited to, a three-color LED (or a three-color laser). The lens assembly 1231 is an optical lens capable of transmitting the illumination light emitted by the light source assembly to form imaging light. It may be a single lens or a combination of two or more lenses. When this imaging light is projected onto a target, it forms an image. This imaging light is the light transmitted by the lens assembly 1231. It is different from the illumination light emitted by the light source assembly. When projected onto a target, this illumination light only forms an illuminated area, but when projected onto a target, the imaging light can form a pattern.

[0045] The image projection device 123 is positioned to the side of the X-ray source. The imaging light emitted by the image projection device 123 is reflected by the reflector 122 into the X-ray limiting channel 1211. The light then passes through the beam limiter 120 through the X-ray limiting channel 1211 to form an image. Because the image projection device 123 itself has imaging capabilities, the resulting image can be a picture, a video, or both, enriching what the doctor sees and providing more information and prompts to the doctor or other viewers.

[0046] The X-ray limiting channel 1211 also constrains the imaging light, allowing part of the imaging light to be emitted from the light outlet, while part of the imaging light is blocked by the X-ray limiting device 121 (such as a lead window). Ultimately, when the imaging light and the X-ray irradiate the same target, the image formed by the imaging light and the irradiation area of ​​the X-ray can overlap with each other. The image includes a light field 131 (such as a light field) used to represent the irradiation area of ​​the X-ray. Figure 6-10 As shown in FIG. 1 ). The light field 131 replaces the illumination area formed by the original LED light source (i.e., the light field of the LED light). Compared to the original LED light source simply forming a light field through the illumination area, the light field 131 is formed by the image projection device 123 itself, so it can be higher definition. The color and brightness of the light field 131 can be adjusted by adjusting the parameters of the image projection device 123, which not only makes the display of the light field 131 more flexible, but also makes it easier for doctors to observe.

[0047] In some embodiments, the image further includes additional light field information for displaying auxiliary medical information in the light field 131. The additional light field information may display auxiliary information that is helpful to the doctor's operation, such as, but not limited to, at least one of light field size, positioning markers, patient information, exposure parameters, cross centerline, ionization chamber position, and small body positioning images.

[0048] Please refer to Figure 6-10 The crosshairs in the figure (mostly red in practice) represent the crosshairs 132 of the light field. While the crosshairs of a conventional beam limiter 120 are formed by a shadow cross pattern created by a cross-shaped light window (a transparent glass plate with crosshairs attached) blocking the light from the LED light source, the image projection device 123 in this application can directly project a crosshair pattern to form the crosshairs 132.

[0049] Please refer to Figure 6 and 7 , the figure shows that the light field size is displayed on the light field 131. After adjusting the light field, the doctor usually needs to know the current size of the light field, that is, the side length of the light field. In traditional X-ray imaging systems, because the LED light source can only display the light field in the form of lighting, its light field cannot be displayed in any text. The light field size information is usually viewed on the head 100 or the PC display screen. However, when the doctor is guiding the patient to position, the line of sight is mainly on the patient, that is, directly seeing the light field. Therefore, after the light field is formed using the image projection device 123, the light field size can be directly displayed in the light field. Figure 6 and 7 In the , the current light field size is displayed in different forms. Of course, the display of the light field size is not limited to Figure 6 and 7 shown in the form.

[0050] Please refer to Figure 8 In some embodiments, the light field 131 may also display patient information, exposure parameters, and photographed area information. Figure 9 In some embodiments, the light field 131 may also display the position of the ionization chamber 133, as shown in the small box in the figure. Figure 10 In some embodiments, the light field 131 may further display a positioning guidance pattern, such as the right-hand pattern 134 shown in the figure. In addition, the positioning guidance pattern may also include but is not limited to a body position map, posture information, etc.

[0051] Of course, the above Figure 6-10 This is merely an illustration of some specific examples of the light field additional information. In other embodiments, the light field additional information may also include but is not limited to advertisements, teaching videos, child comforting videos and other videos.

[0052] Compared with the original LED light source that simply forms a light field by illuminating the area, the image projection device 123 is used to form an image. By utilizing its own imaging function, it can not only display the X-ray light field (displayed through the light field 131), but also integrate more information in the light field, making it more convenient for doctors to obtain information and assist in shooting, thereby improving the convenience and accuracy of operation.

[0053] For further information, please refer to Figure 3 and 4 In order to ensure that the light field 131 formed by the image projection device 123 can be kept coincident with the irradiation area of ​​the X-ray, there are corresponding requirements for the emission direction of the imaging light in the image projection device 123. In some embodiments, please refer to Figure 3 The beam limiter 120 also includes an adjusting device 124, and the image projection device 123 is installed on the adjusting device 124. The adjusting device 124 is used to adjust the emission direction of the imaging light of the image projection device 123 so that the light field 131 formed by the image projection device 123 can be kept coincident with the irradiation area of ​​the X-ray.

[0054] Please refer to Figure 5In one embodiment, taking the lens assembly 1231 of the image projection device 123 as an example, the axial direction of the lens assembly 1231 is defined as the X-axis, and two directions perpendicular to each other along the radial direction of the lens assembly 1231 and also perpendicular to the X-axis are defined as the Y-axis and the Z-axis. These X, Y, and Z axes are mutually perpendicular. The adjustment device 124 has six degrees of freedom, including translation in the X, Y, and Z directions, and rotation in the XY, XZ, and YZ planes. This allows adjustment in at least one of these six directions, allowing the image projection device 123 to be adjusted in order to adjust the emission direction of the imaging light from the image projection device 123. This adjustment device 124 eliminates the need for precise assembly of the image projection device 123. Once the image projection device 123 is mounted on the adjustment device 124, fine-tuning can be performed to ensure the accuracy of the emission direction of the imaging light.

[0055] Of course, in other embodiments, the image projection device 123 can be assembled in the correct position in a very precise manner when the image projection device 123 is assembled, without the need for subsequent fine-tuning operations, but this places very high demands on assembly and processing.

[0056] For further information, please refer to Figure 3 and 4 In some embodiments, the reflector 122 is arranged on the propagation path of the X-rays, and the reflector 122 is made of a material that can allow X-rays to pass through. The side of the reflector 122 facing the X-ray limitation channel 1211 is a reflective surface, and the reflective surface is arranged at an angle. The image projection device 123 is arranged on the side of the reflector 122, and the imaging light of the image projection device 123 is directed toward the reflective surface, and the reflective surface reflects the imaging light toward the X-ray limitation channel 1211.

[0057] The X-rays are generated in the tube 110. In some embodiments, the electrons excited by the cathode filament bombard the anode target surface. The area where the electrons hit the anode target surface is where the X-rays are generated, which is called the X-ray focus (or tube focus A). Figure 4 After the imaging light is emitted from the surface of lens assembly 1231, it spreads outward in a cone shape. The light beam of each pixel on the projected image (i.e., the image of the imaging light) extends backward from lens assembly 1231 and converges into an area, such as a surface. This area is the virtual light source B formed by the imaging light relative to lens assembly 1231. The mirror image position of this virtual light source B relative to reflector 122 is the mirror image virtual light source B'.

[0058] To ensure that the image projected by the image projection device 123 consistently coincides with the X-ray irradiation area, in some embodiments, the mirror image virtual light source B' formed by the virtual light source B relative to the reflector 122 coincides with the tube focal point A. This way, after being reflected by the reflector 122, the imaging light from the image projection device 123 is equivalent to the light emitted from the tube focal point A. The imaging light is also blocked by the lead window of the beam limiter 120 before irradiating the patient. At this point, the range of the visible imaging light coincides with the actual X-ray irradiation area. Because the mirror image virtual light source B' overlaps with the tube focal point A, the image projected by the image projection device 123 coincides with the actual X-ray irradiation area on any plane at any distance from the handpiece 100, without deviation. This "coincidence" here refers to the center of the mirror image virtual light source B' coinciding with the center of the tube focal point A, or the deviation being within a certain distance. This is sufficient as long as the range of the projected image formed by the imaging light and the X-ray irradiation area are consistent at any projection distance.

[0059] Furthermore, when the image projection device 123 replaces the LED light source to generate the visible light field, in order to improve the light field consistency index and the light field edge contrast index, the image projection device 123 can be further optimized.

[0060] Regarding the consistency of the light field, it is related to the projection ratio of the image projection device 123. The visible light generated by the image projection device 123 should indicate the range of the X-rays. Therefore, the visible light angle range of the image projection device 123 should cover the angle range of the X-ray source. In traditional X-ray imaging systems, the light source is generated by LED. The LED light source is approximately spherical light, and its light-emitting angle is much larger than the light-emitting angle of the X-rays of the tube 110, so this issue does not need to be considered. However, the light source angle emitted by the image projection device 123 (equivalent to the "throw ratio" commonly used in the industry for the image projection device 123) is smaller.

[0061] In order to improve the consistency of the light field, in some embodiments, please refer to Figure 11 The angle β corresponding to the short side of the image projection device 123 is greater than or equal to twice the target angle of the tube 110. Alternatively, in some embodiments, the projection ratio of the image projection device 123 is less than or equal to 1.2.

[0062] For example, the target angle of the tube (half of the X-ray emission angle) in the current X-ray imaging system on the market is in the range of 12° to 14°. For a common image projection device 123 with a projection screen of 16:9, the angle corresponding to the short side of the screen is required to be ( Figure 11 The β angle) is greater than the target angle × 2, that is, if the target angle is 12°, the β angle of the image projection device 123 is greater than or equal to 24°; if the target angle is 14°, the β angle of the image projection device 123 is greater than or equal to 28°.

[0063] In some embodiments, for example, in an image projection device 123 with a common projection screen of 16:9, the relationship between the short side angle β and the projection ratio K of the image projection device 123 is as follows:

[0064]

[0065] According to the formula, the short side angle β of the image projection device 123 is set based on the required projection ratio K of the image projection device 123 to ensure better light field consistency in the X-ray imaging system.

[0066] For the light field edge contrast, it is related to the diameter of the virtual light source of the lens assembly 1231. To obtain better light field edge contrast, please refer to Figure 12 In some embodiments, the light source edge contrast of the edge of the image projected by the image projection device 123 is greater than 4. Figure 12 In some embodiments, the diameter of the virtual light source of the lens assembly 1231 is less than or equal to 4.5 mm.

[0067] Specifically, please refer to Figure 12 Since the diameter of the virtual light source of lens assembly 1231 (e.g., a surface light source) is e, and it is blocked by the X-ray limiting device 121 (e.g., a lead window) at a distance d from it, the edge of the light field will eventually form a penumbra with a width of h on the imaging plane. The wider the penumbra, the lower the edge contrast, ultimately failing to meet the regulatory requirements for light field edge contrast. The geometric relationship between the relevant parameters is:

[0068]

[0069] According to the above formula, the penumbra width h is related to the surface light source size e, the distance d from the light source to the X-ray limiting device 121, and the projection distance l. The regulatory requirement for the projection distance of edge contrast testing is 1 meter, so the projection distance l is fixed. The only factors affecting the penumbra width are the exit pupil diameter e of the image projection device 123 and the distance d from the X-ray limiting device 121 to the image projection device 123. To meet these requirements, the parameters of the image projection device 123 (e value) and the structural design of the beam limiter 120 (d value) must be selected to ensure that the light source edge contrast is greater than 4, with sufficient margin.

[0070] On the other hand, some embodiments of the present application also provide another X-ray imaging system head 100, which includes a tube 110 and a beam limiter 120. The beam limiter 120 has an X-ray limiting device 121 and an image projection device 123. The X-ray limiting device 121 forms an X-ray limiting channel 1211. The X-rays emitted by the X-ray source pass through the beam limiter 120 through the X-ray limiting channel 1211 to be emitted toward the object to be detected.

[0071] The image projection device 123 is capable of projecting imaging light. The imaging light passes through the beam limiter 120 via the X-ray limiting channel 1211 to form an image. The image includes a light field 131 for displaying the X-ray irradiation area. In this embodiment, the image projection device 123 can also project imaging light using structures other than the aforementioned emitting element to form the light field 131.

[0072] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A head of an X-ray imaging system, characterized in that: include: a tube, the tube being used to generate an X-ray source and emit X-rays; and a beam limiter, the beam limiter comprising an X-ray limiting device, a reflector, an image projection device, and an adjustment device, the X-ray limiting device forming an X-ray limiting channel, the X-rays emitted by the X-ray source passing through the X-ray limiting channel and exiting the beam limiter to be emitted toward the object to be detected; The image projection device is capable of emitting imaging light, which is reflected by the reflective member to the X-ray limiting channel and passes through the beam limiter through the X-ray limiting channel to form an image, wherein the image includes a light field for representing an irradiation area of ​​the X-ray and light field additional information for displaying medical auxiliary information in the light field; The image projection device is mounted on the adjustment device, and the adjustment device is used to adjust the emission direction of the imaging light of the image projection device so that the light field formed by the image projection device can be kept coincident with the irradiation area of ​​the X-ray.

2. The handpiece according to claim 1, wherein: The reflector reflects the imaging light to the X-ray limiting channel, and the virtual light source of the imaging light relative to the image projection device, the mirror image virtual light source on the reflector coincides with the focus of the tube.

3. The handpiece according to claim 2, wherein: The reflector is arranged on the propagation path of the X-rays, and the reflector is made of a material that can allow the X-rays to pass through. The side of the reflector facing the X-ray limiting channel is a reflective surface, and the reflective surface is arranged at an angle. The image projection device is arranged on the side of the reflector, and the imaging light of the image projection device is projected toward the reflective surface.

4. The handpiece according to any one of claims 1 to 3, characterized in that: The opening angle β corresponding to the short side of the image projection device is greater than or equal to twice the tube target angle of the tube.

5. The handpiece according to any one of claims 1 to 3, characterized in that: The projection ratio of the image projection device is less than or equal to 1.

2.

6. The handpiece according to any one of claims 1 to 5, characterized in that: The light source edge contrast of the edge of the image projected by the image projection device is greater than 4.

7. The handpiece according to any one of claims 1 to 5, characterized in that: The diameter of the virtual light source formed by the lens assembly is less than or equal to 4.5 mm.

8. The handpiece according to any one of claims 1 to 7, wherein: The additional light field information includes at least one of light field size, positioning marker line, patient information, exposure parameters, cross center line, ionization chamber position and small body positioning picture.

9. The handpiece according to any one of claims 1 to 7, wherein: The images include pictures and / or videos.

10. The handpiece according to any one of claims 1 to 9, characterized in that: The adjustment device has an adjustment freedom in at least one direction to adjust the emission direction of the imaging light of the image projection device.

11. The handpiece according to any one of claims 1 to 10, characterized in that: The image projection device comprises a light source assembly of multiple colors and a lens assembly for forming an image. The illumination light emitted by the light source assembly is transmitted through the lens assembly to form the imaging light.

12. A head of an X-ray imaging system, characterized in that: include: a tube having an X-ray source for emitting X-rays; and a beam limiter, the beam limiter comprising an X-ray limiting device and an image projection device, the X-ray limiting device forming an X-ray limiting channel, the X-rays emitted by the X-ray source passing through the beam limiter through the X-ray limiting channel to be emitted toward the object to be detected; The image projection device can project imaging light, and the imaging light passes through the beam limiter through the X-ray limiting channel to form an image. The image includes a light field for displaying the irradiation area of ​​the X-ray.

13. An X-ray imaging system, characterized in that: The invention comprises a handpiece according to any one of claims 1 to 12 and a detector for receiving X-rays emitted by the handpiece.

Images