Uniform light illumination device and face photo acquisition device comprising same
By combining a conical reflective cavity, a light-diffusing plate, and a diffuser, along with a diffuse reflection coating, the problem of uneven illumination was solved, achieving uniform illumination in facial photographs and improving image quality and diagnostic accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-29
- Publication Date
- 2026-03-20
AI Technical Summary
Uneven illumination from existing lighting devices causes noise and color cast during facial image acquisition, affecting the image signal-to-noise ratio and reducing the accuracy and stability of visual diagnosis.
It adopts a combination structure of conical reflective cavity, light uniform plate and light diffuser, combined with diffuse reflection coating, to ensure uniform light distribution through multiple reflections and scattering, and avoid light spots and overexposed areas.
It achieves uniform facial illumination, improves image quality, ensures image usability and diagnostic reliability, and meets the needs of digital pulse diagnosis.
Smart Images
Figure CN224008375U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of lighting, in particular to a uniform light illumination device and a face photograph collection device comprising the same. BACKGROUND
[0002] Pulse diagnosis is the core of the four diagnostic methods of traditional Chinese medicine, which is used to fully understand the patient's condition and provide the basis for diagnosis and treatment. Among them, pulse diagnosis is to observe the external manifestations of the patient, such as complexion, tongue, body posture, skin changes, etc., to obtain disease information. For example, the color of the tongue can reflect the function of the viscera and the cold and heat of the disease. Taking a patient's face photo is the basis for realizing the digitization of pulse diagnosis.
[0003] Uniform light illumination of the face is very important for photograph collection in pulse diagnosis. Especially for diagnostic features such as tongue and complexion that require subtle analysis, noise and color cast can cause the signal-to-noise ratio of the image to decrease; low-quality images not only affect the observation of the physician, but also cause misjudgment when the pulse diagnosis algorithm analyzes, reducing the accuracy and stability of pulse diagnosis. Uniform light can ensure that the details and colors of the face skin can be truly and accurately presented. When the light is not uniform, shadows, light spots, and overexposed areas will be produced, and the photos with different brightness will cover some features of the face, or even distort the features; for example, some parts of the face may not be able to clearly see the details due to strong light reflection, while other areas may appear blurred or lose details due to insufficient light. The light sources of general illumination devices are concentrated in certain positions, resulting in a large difference in brightness in different areas, forming obvious bright and dark areas; non-uniform light will cause inaccurate feature extraction, reducing the usability of the image and the reliability of diagnosis. CONTENT OF THE UTILITY MODEL
[0004] The utility model aims at the deficiency in the prior art, provides a kind of uniform light illumination device and the face photograph collection device comprising it to solve the problem of non-uniform light when shooting face photo in digital pulse diagnosis.
[0005] To achieve the above object, the technical scheme adopted by the utility model is as follows:
[0006] The present application provides a kind of uniform light illumination device, device includes light source, uniform light board, soft light board, uniform light board is set between light source and soft light board, illumination device further includes conical reflector, conical reflector two ends are open, the size of two ends opening is big in one end, small in one end, soft light board is set in the smaller end of conical reflector, soft light board is fixedly set in the edge of conical reflector, soft light board side away from conical reflector is sequentially fixedly set with uniform light board, light source;Conical reflector's inner wall is provided with diffuse reflection coating.
[0007] The light emitted by the light source transmits through the light homogenizing plate, the light homogenizing plate scatters the light field, changes the propagation direction of the light field, avoids direct irradiation into the eyes of the user, and causes harm to the eyes. The light transmitting through the light homogenizing plate passes through the soft light plate, and the light-transmitting plate attenuates the intensity of the transmitted light to prevent the light intensity from being too large. The diffuse reflection coating can effectively uniformly scatter the light entering the cavity, ensuring that the light is not directly reflected, but forms a more soft and uniform light field through scattering. The light field transmitting through the soft light plate enters the conical reflective cavity, and under the reflection of the diffuse reflection coating on the inner wall of the conical reflective cavity, it is fully diffused, so that the light field of the face of the person being photographed is uniformly distributed. The light field reflects off the face, the light field containing face information transmits through the middle region of the soft light plate and enters the camera, i.e. the photo of the face of the person being photographed is obtained; the quality of the photo is high.
[0008] The conical reflective cavity has one side with a large size and the other side with a small size. Due to the conical structure of the reflective cavity, the shape of the conical reflective cavity can guide the light towards the large opening area of the reflective cavity, and the light will be gradually diffused when reflected, so that the light range is increased, and the problems of light spot and overexposure caused by concentrated light are avoided. The conical geometry makes the scattering angle of the light gradually increase, so that the coverage range of the light is wider, and after multiple reflections in the cavity, the intensity of the light can be uniformly distributed throughout the cavity; this avoids the situation that the light is concentrated in a local area, causing the face to be too bright in the local area, and also avoids the situation that the light is excessively diffused, resulting in insufficient light intensity.
[0009] Further, the thickness of the diffuse reflection coating is 2-30 pm, and the thickness of the diffuse reflection coating gradually decreases from the small size end to the large size end of the conical reflective cavity. The thickness of the diffuse reflection coating is larger in the area closer to the light source, and the thickness of the diffuse reflection coating is smaller in the area farther from the light source. The thicker diffuse reflection layer has a larger scattering intensity for the light field; the thinner diffuse reflection layer has a weaker scattering intensity for the light field, and the thin coating layer can avoid excessive scattering, avoid the situation that the scattering causes the light field to have a low energy, appropriately guide the light, and maintain the stability of the light intensity. The light entering the reflective chamber is first reflected by the thicker diffuse reflection layer, and the light field with a larger intensity forms extensive scattered light after scattering, so that the light is not concentrated in a small area, but is expanded to a wider area, thereby avoiding the local light spot and over-bright phenomenon. The gradually decreasing thickness of the coating helps to reduce excessive scattering of the light, so that the light can be more orderly guided to the downstream area, avoiding the situation that the light is lost or insufficient. The area with a thinner coating layer helps to guide the light to the required area, controls the concentration of the scattered light, so that the light can be guided to the collection area, while avoiding excessive diffusion leading to insufficient or uneven light intensity. This avoids the light spot or dark area caused by excessive light reflection, so that the light field is more uniform.
[0010] Furthermore, the arithmetic mean roughness of the diffuse reflection coating surface ranges from 1 to 10 μm, gradually decreasing from the smaller end of the conical reflective cavity to the larger end. The roughness of the diffuse reflection layer near the light source is greater than that away from the light source. Higher roughness results in a less smooth surface and stronger scattering, causing light to diffuse over a wider angle, thus covering a broader area and allowing more intense light to diffuse fully. High-roughness regions have a larger scattering angle and range, dispersing excessively strong light sources and illuminating the surrounding area more evenly, avoiding localized overexposure. Low-roughness regions have a relatively smaller scattering angle and range; the smaller scattering angle makes it easier to achieve a uniform light field distribution. Since the light in this region has already undergone preliminary scattering and is weaker, low roughness helps maintain the relative concentration of the light, ensuring that the light is guided to the target area and avoiding excessive diffusion that could lead to insufficient light or poor uniformity.
[0011] Furthermore, the diffuse reflection coating is made of titanium dioxide or epoxy resin with added titanium dioxide particles. Titanium dioxide has high optical emissivity and diffuse reflection capability. Its high reflectivity and high scattering properties ensure that light maintains high illumination uniformity after multiple reflections within the reflective cavity, effectively reflecting and scattering incident light to achieve uniform light distribution. Titanium dioxide itself possesses excellent durability and oxidation resistance, effectively preventing performance degradation due to long-term use and ensuring good stability of the device over extended periods.
[0012] Furthermore, the diameter of the larger end of the conical reflector is 200-220 mm, and the diameter of the smaller end is 140-160 mm; the angle between the conical surface of the conical reflector and the central axis is 10-15 degrees.
[0013] Furthermore, the diffuser is circular, with the same diameter as the smaller end of the conical reflective cavity. The diffuser has a first region, a second region, and a third region, with the second region located between the first and third regions.
[0014] Furthermore, on the diffuser, the rectangle and the small circle are concentric and located at the center of the diffuser. The diameter of the small circle is 75-95 mm. The area outside the small circle is the first region, the area inside the small circle and outside the rectangle is the second region, and the area inside the rectangle is the third region.
[0015] Further, the first area and the third area are light-transmissive, the second area is non-light-transmissive, and the rectangular shape is the same as the length-width ratio of the field of view of the camera for collecting the image. The light-transmissive first area allows the light of the light source to pass through the soft light plate to the conical reflector, the light reflected from the face passes through the third area into the camera, and the photographing is performed. The non-light-transmissive second area prevents the strong light from directly irradiating the eyes of the photographed person, and avoids the stray light from entering the camera, thereby avoiding the influence of the stray light on the target light and improving the imaging quality. The rectangular shape is similar to the field of view of the camera, and the distance between the camera and the light-transmissive plate is just enough to not be able to photograph the second area on the soft light plate.
[0016] Further, the outer diameter of the light homogenizing plate is the same as the diameter of the small-size end of the conical reflector, and the inner diameter of the light homogenizing plate is 90mm. The outer diameter of the light homogenizing plate is the same as the diameter of the small-size end of the conical reflector, which can ensure that the light is uniformly scattered through the light homogenizing plate, and avoids the concentration or excessive dispersion of the light. The light is uniformly distributed to the soft light plate and the reflector, and the light intensity uniformity of the entire illumination system is maintained.
[0017] The application also provides a face photograph collecting device, which comprises a camera and the light homogenizing illumination device, the camera is arranged at the middle position of the light source in the light homogenizing illumination device, and the camera is arranged on the central axis of the conical reflector, and the side of the conical reflector away from the soft light plate is used for placing the face of the photographed person.
[0018] Compared with the prior art, the application has the following beneficial effects:
[0019] (1) The shape of the reflector chamber is set as a cone, which can guide the light to the large opening area of the reflector, and the light is gradually diffused when reflected, so that the illumination range is increased, and the light field intensity on the face is uniform. The light homogenizing plate performs the first scattering on the light field, and the light field entering the conical reflector is secondarily reflected on the side wall by the diffuse reflection coating. Under the action of the two reflections, the intensity distribution of the light field is uniform, which helps to improve the photographing quality of the face photograph.
[0020] (2) This application also makes the distribution of the light field more uniform by adjusting the thickness and roughness of the diffuse reflection coating on the inner wall of the conical reflective cavity. Specifically, from the small-size end to the large-size end, the thickness and roughness of the diffuse reflection coating gradually decrease. The gradual decrease in thickness makes the scattering intensity of the light field by the diffuse reflection layer gradually decrease. The light emitted by the light source is first reflected by the thicker diffuse reflection layer, and after scattering, it forms a wide range of scattered light, which makes the light spread to a wider area. The thinner coating area helps to guide the light to the required area, control the concentration of the scattered light, and enable the light to be guided to the collection area, while avoiding excessive diffusion that leads to insufficient light intensity or unevenness. The reduction in roughness makes the scattering angle and scattering range of the light field gradually decrease, guiding the distribution of the light field to be more uniform, ensuring that the light can be guided to the target area, and avoiding excessive diffusion that leads to insufficient light or poor uniformity. Attached Figure Description
[0021] Figure 1 A schematic diagram of a uniform lighting device provided by this utility model;
[0022] Figure 2 A schematic diagram of a light-diffusing plate in a light-diffusing illumination device provided by this utility model;
[0023] Figure 3 A schematic diagram of a diffuser in a uniform lighting device provided for utility model purposes;
[0024] Figure 4 This is a disassembly diagram of a uniform lighting device provided by this utility model;
[0025] Figure 5 A three-dimensional schematic diagram of a facial photo acquisition device provided by this utility model;
[0026] Figure 6 A flowchart illustrating the use of a facial photo acquisition device provided by this utility model.
[0027] Icons: 1-Light source; 2-Light diffuser; 3-Light diffuser; 31-First area; 32-Second area; 33-Third area; 4-Conical reflector; 5-Camera. Detailed Implementation
[0028] To make the implementation process of this utility model clearer, a detailed description will be provided below in conjunction with the accompanying drawings.
[0029] This utility model provides a uniform lighting device, such as Figure 1As shown, the device includes a light source 1, a light uniformity plate 2, a soft light plate 3, and a conical light-reflecting cavity 4. The light source 1 is a ring-shaped stable light source with a color temperature of 5500K and a brightness of 3000 Lux. The light source 1 is used to realize a natural light-imitating shooting environment and ensure the authenticity of the collected facial (or tongue) images. The inner diameter of the ring-shaped light source 1 is 90-110 mm, and preferably, the inner diameter of the light source 1 is 100 mm, and the outer diameter is 140-150 mm, and preferably, the outer diameter of the light source 1 is 145 mm. The ring shape is convenient for positioning a camera 5 in the middle position for collecting facial photos, and can also avoid more light entering the human eye.
[0030] As shown in Figure 2 , the light uniformity plate 2 is ring-shaped, and the outer diameter is the same as the outer diameter of the light source 1 (also the diameter of the small size end of the conical light-reflecting cavity 4), and the inner diameter is slightly larger than the inner diameter of the light source 1 or the same as the inner diameter of the light source 1. Slightly larger is conducive to uniform light for the light field of the inner diameter edge of the light source 1, and the width can be 1.1-1.2 times the width of the light source 1. The inner diameter of the light uniformity plate 2 can be 0.8-0.95 times the inner diameter of the light source 1. The light uniformity plate 2 has good optical uniformity and high light transmittance, and can be acrylic with laser-engraved microstructures on the surface, or frosted optical glass, or polyester diffusion film, etc. It has good scattering light field capability. The light uniformity plate 2 is arranged between the light source 1 and the soft light plate 3, and the material of the soft light plate 3 is acrylic, including translucent light-transmitting acrylic and black non-light-transmitting acrylic.
[0031] The soft light plate 3 is circular, and the diameter is the same as the diameter of the small size end of the conical light-reflecting cavity 4. The soft light plate 3 is provided with a first area 31, a second area 32, and a third area 33, which are arranged between the first area 31 and the third area 33, as shown in Figure 3 . On the soft light plate 3, the rectangle and the small circle are concentric and located at the center of the soft light plate 3. The diameter of the small circle is 75-95 mm, and preferably, the diameter of the small circle can be 88 mm. The first area 31 is outside the small circle, the second area 32 is inside the small circle and outside the rectangle, and the third area 33 is inside the rectangle. The shape of the rectangle is the same as the length-width ratio of the field of view of the camera 5 for collecting images. The first area 31 and the third area 33 are light-transmitting and made of translucent light-transmitting acrylic, and the second area 32 is non-light-transmitting and made of black non-light-transmitting acrylic. The centers of the light uniformity plate 2 and the soft light plate 3 are collinear with the central axis of the conical light-reflecting cavity 4.
[0032] The lighting device further comprises a conical reflector cavity 4, which is open at both ends, and the sizes of the two ends are different, one end is large and the other end is small; the diameter of the large end of the conical reflector cavity 4 is 200-220mm, preferably 210mm, and the diameter of the small end is 140-160mm, preferably 150mm; the angle between the conical surface of the conical reflector cavity 4 and the central axis is 10-15 degrees, preferably 11-12 degrees. The soft light plate 3 is arranged at the smaller end of the conical reflector cavity 4, and the soft light plate 3 is fixedly arranged at the edge of the conical reflector cavity 4, which can be fixed by adhesion, or by clamping groove or pressing plate, and the specific fixation method is not limited. The light source 1 and the light homogenizing plate 2 are fixedly arranged in sequence on the side of the soft light plate 3 away from the conical reflector cavity 4. A diffuse reflection coating is arranged on the inner wall of the conical reflector cavity 4. The material of the diffuse reflection coating is titanium dioxide or epoxy resin with titanium dioxide particles. The thickness of the diffuse reflection coating is 2-30μm, and the thickness of the diffuse reflection coating gradually decreases from the small end to the large end of the conical reflector cavity 4; further, it is divided into three sections, including a middle section, a section away from the light source 1, and a section close to the light source 1, the thickness of the diffuse reflection layer in the section close to the light source 1 is 10-30μm, the thickness of the diffuse reflection layer in the middle section is 5-10μm, and the thickness of the diffuse reflection layer in the section away from the light source 1 is 2-5μm. The arithmetic average roughness (Ra) of the surface of the diffuse reflection coating is 1-10μm, and the arithmetic average roughness of the surface of the diffuse reflection coating gradually decreases from the small end to the large end of the conical reflector cavity 4; further, the Ra of the diffuse reflection coating in the section close to the light source 1 is 5-10μm, and the Ra of the diffuse reflection coating in the section away from the light source 1 is 1-5μm.
[0033] The color of the diffuse reflection coating is dark blue; the dark blue diffuse reflection coating forms a more realistic image, because it reflects more blue light with shorter wavelengths, so that the blue light can be better preserved in the reflector cavity, and absorbs more red light and green light with longer wavelengths, which is closer to the natural light effect perceived by the human eye in the real environment, avoiding the influence of light color deviation on the shooting result. That is, the spectral characteristics of the dark blue coating help to maintain the color balance of the image, avoid red or green deviation, and make the image closer to the true facial color; the dark blue color absorbs stray light, reduces the noise level of the image, and enhances the recognition of facial features, providing high-quality data for artificial intelligence analysis. Figure 4 The disassembly schematic diagram of the light homogenizing lighting device.
[0034] The application further provides a face photograph collecting device, which comprises a camera 5 and the uniform light illuminating device, the camera 5 is arranged at the middle position of the light source 1 in the uniform light illuminating device, the camera 5 is arranged on the central axis of the conical reflecting cavity 4, and the conical reflecting cavity 4 is used for placing the face of the person to be photographed away from the side of the soft light plate 3. The camera 5 adopts a 12 million, 130-degree wide-angle non-distortion high-definition camera, so that the collected illumination is clearer. The face collecting device can realize uniform illumination in a multi-angle range, effectively avoids problems such as light spots and shadows, ensures the light intensity consistency of the imaging area, and makes the collected image have higher clarity and accuracy, thereby providing protection for subsequent image processing and accurate analysis of diagnosis algorithms.
[0035] Further, in order to facilitate use, a shell can be arranged on the outside of the face collecting device, the height of the main shell part is 40 cm, which is a comfortable collecting height for a person in a sitting position. In order to facilitate the use of the person to be photographed, a chin support can be arranged at the lower side of the larger end of the conical reflecting cavity 4, and the chin support can be wrapped with a rubber ring to ensure a comfortable collecting environment for the collector. In order to facilitate the adjustment of the angle of the camera 5, the camera 5 can be arranged on a steering wheel that can rotate up and down, and the shooting angle can be finely adjusted as required. In use, the head of the collector is placed on the chin support, the face is uniformly illuminated, and the camera 5 shoots the face or tongue photograph. Optionally, the face collecting device further comprises a ventilation and disinfection system, which adopts a fan for ventilation and an ultraviolet lamp for disinfection, and is respectively arranged on the side and the upper side of the uniform light illuminating device part. After the collection is completed, ventilation and disinfection are required for not less than 1 minute to ensure the hygiene of the equipment and meet the hygiene requirements of the medical environment. The stereographic view is shown in Figure 5
[0036] Figure 6 The use process of the face collecting device comprises the following steps: S101, placing the head of the collector on the chin support and turning on the camera 5 and the light source 1; S102, rotating the steering wheel to collect image information of the face and the tongue; and S103, after the collection is completed, turning on the fan and the ultraviolet lamp to perform ventilation and disinfection.
[0037] The preferred embodiments of the utility model are merely used for limiting the utility model, and the utility model can be changed and varied for the person skilled in the art. Any modification, equivalent replacement, improvement and the like within the spirit and principle of the utility model should be included in the protection scope of the utility model.
Claims
1. A uniform light illumination device, the device comprising a light source, a uniform light plate, and a diffuser, wherein the uniform light plate is disposed between the light source and the diffuser, characterized in that, The lighting device further includes a conical reflective cavity, which is open at both ends with one end larger than the other. A diffuser is disposed at the smaller end of the conical reflective cavity and is fixedly disposed at the edge of the conical reflective cavity. A light-diffusing plate and a light source are sequentially fixedly disposed on the side of the diffuser away from the conical reflective cavity. A diffuse reflection coating is disposed on the inner wall of the conical reflective cavity.
2. The uniform illumination device according to claim 1, characterized in that, The thickness of the diffuse reflection coating is 2-30 μm, and the thickness of the diffuse reflection coating gradually decreases from the smaller end to the larger end of the conical reflective cavity.
3. The uniform illumination device according to claim 2, characterized in that, The arithmetic mean roughness of the diffuse reflection coating surface is 1-10 μm, and the arithmetic mean roughness of the diffuse reflection coating surface gradually decreases from the small size end to the large size end of the conical reflective cavity.
4. The uniform illumination device according to claim 3, characterized in that, The diffuse reflection coating is made of titanium dioxide or epoxy resin with added titanium dioxide particles.
5. The uniform illumination device according to claim 4, characterized in that, The diameter of the larger end of the conical reflective cavity is 200-220 mm, and the diameter of the smaller end is 10-15 degrees.
6. The uniform illumination device according to claim 5, characterized in that, The diffuser is circular, with a diameter that is the same as the diameter of the smaller end of the conical reflective cavity. The diffuser has a first region, a second region, and a third region, with the second region located between the first region and the third region.
7. The uniform illumination device according to claim 6, characterized in that, On the diffuser plate, a rectangle and a small circle are concentric and located at the center of the diffuser plate. The diameter of the small circle is 75-95 mm. The area outside the small circle is the first region, the area inside the small circle and the area outside the rectangle is the second region, and the area inside the rectangle is the third region.
8. The uniform illumination device according to claim 7, characterized in that, The first and third regions are light-transmitting, while the second region is opaque. The shape of the rectangle has the same aspect ratio as the field of view of the camera capturing the image.
9. The uniform illumination device according to claim 8, characterized in that, The outer diameter of the light-diffusing plate is the same as the diameter of the smaller end of the conical reflective cavity, and the inner diameter of the light-diffusing plate is 90 mm.
10. A facial photograph acquisition device, the acquisition device comprising a camera, characterized in that, The acquisition device further includes the uniform illumination device according to any one of claims 1-9, wherein the camera is disposed in the middle position of the light source in the uniform illumination device, the camera is disposed on the central axis of the conical reflective cavity, and the side of the conical reflective cavity away from the diffuser is used to place the face of the person being photographed.