Multi-CCD imaging device

Abstract

The utility model discloses a multi-CCD (Charge Coupled Device) imaging device, wherein an imaging lens assembly, a light splitting assembly and a multi-CCD receiving device are connected in sequence; the imaging lens assembly guides imaging polychromatic light to the light splitting assembly, the light splitting assembly has a certain thickness between the imaging lens assembly and the multi-CCD receivers, and the multi-CCD receivers are arranged at the corresponding positions of the light splitting assembly in the emergent directions of different positions and receive light of corresponding wave bands; and the imaging lens assembly has a first optical structure design, and the first optical structure design is configured to compensate aberration introduced by the light splitting assembly in light path transmission between the imaging lens and the multi-CCD receiving device. According to the multi-CCD imaging device realized by the utility model, aberration design of the light splitting element is carried out at the imaging lens end, preliminary wavelength selective light splitting is carried out by using the inclined plane, and then screening is carried out by using different end surfaces to reduce crosstalk, so that the resolution is high, the light splitting energy loss is low, and the color crosstalk is small.

Description

Technical Field

[0001] This utility model belongs to the field of display information measurement technology, specifically relating to a multi-CCD imaging device. Background Technology

[0002] Multi-CCD cameras, especially 3CCD cameras (triple-CCD cameras), are typically used in applications requiring high color fidelity and image quality. Since 3CCD cameras use three CCD sensors to capture images of the red, green, and blue color channels respectively, generally, the light from the object passing through the imaging lens needs to be split into three channels by a beam splitter.

[0003] Beam splitters come in various forms, including regular and irregular beam splitting elements. To achieve better beam splitting effects and improve resolution and accuracy, there are currently multiple implementation methods for beam splitters. For example, patent CN113728224A shows a beam splitter composed of multiple irregular prisms. This type of irregularly shaped multi-CCD has a smaller volume, which minimizes the impact of the beam splitter on the aberrations of the entire optical system. Conventional industrial lenses paired with this irregularly shaped beam splitter can achieve good image quality. However, the design of this irregularly shaped beam splitter structure is quite difficult. To ensure that the light sensor receiving surface is perpendicular to the optical axis, the optical axes of multiple receiving surfaces are tilted, which is not conducive to the setting of the reference surface and the installation of CCDs on each surface.

[0004] Another multi-CCD design approach is exemplified by patent JP1999239357A. Figure 1 As shown, this type of beam splitter has a regular design with a horizontal or vertical optical axis, which facilitates the installation of CCD. However, this type of beam splitter is relatively large and the prism glass is relatively thick. Therefore, when this beam splitter is introduced behind a regular lens, it will bring about a large aberration, which is not conducive to high-quality imaging.

[0005] Those skilled in the art need to improve and develop devices for applying spectral splitting to multi-CCD cameras, especially 3CCD cameras, to address the aforementioned problems. Utility Model Content

[0006] Therefore, in view of at least one of the above-mentioned defects or improvement needs of the prior art, the present invention discloses a multi-CCD imaging system, which includes a beam splitting component, an imaging lens component, and a multi-CCD receiving device.

[0007] The imaging lens assembly, beam splitter assembly, and multi-CCD receiver are connected in sequence.

[0008] The imaging lens assembly guides the imaging polychromatic light to the beam splitter. The beam splitter has a certain thickness between the imaging lens assembly and the multi-CCD receiver. The multi-CCD receiver is positioned at corresponding positions in the emission direction of different positions of the beam splitter to receive light of the corresponding wavelength band.

[0009] The imaging lens assembly has a first optical structure design configured to compensate for aberrations introduced by the beam splitter during optical path transmission between the imaging lens and the multi-CCD receiver.

[0010] Further,

[0011] The beam splitter has a certain planar thickness between the imaging lens assembly and the multi-CCD receiver. After the imaging polychromatic light passes through the beam splitter, light of different wavelengths is emitted from the exit surface of the beam splitter in a horizontal or vertical direction.

[0012] Further,

[0013] The beam splitting assembly includes: a beam splitting element group for splitting incident light into at least two wavelengths, wherein the light of each wavelength is split to an outgoing direction at a different location, and the optical path of the light of each wavelength is equal; and a filter element group disposed in at least one direction of the outgoing direction and configured to filter out other wavelengths of light corresponding to the outgoing direction wavelength.

[0014] Further,

[0015] The beam-splitting element in the beam-splitting element group is a cubic prism with a 45° angled coated beam splitter having a certain planar thickness.

[0016] Further,

[0017] The filter element group is a coating layer, which is an inner or outer layer disposed on the beam splitter at a position in the emission direction; or, the filter element group is a filter surface disposed in the optical path outside the position in the emission direction of the beam splitter group.

[0018] Further,

[0019] The filter surface is a filter separately set in the optical path, or integrated on the front side of the multi-CCD receiving device.

[0020] This utility model also discloses a 3CCD imaging system, which includes a beam splitter, an imaging lens assembly, and a 3CCD receiver.

[0021] The imaging lens assembly, beam splitter assembly, and 3CCD receiver are connected in sequence.

[0022] The imaging lens assembly guides the imaging polychromatic light to the beam-splitting assembly. The 3CCD receiver is positioned at three different positions on the beam-splitting assembly corresponding to the emission directions, respectively receiving the RGB band light that has been split. The beam-splitting assembly has a certain planar thickness between the corresponding positions of the three beam-splitting bands of the imaging lens assembly and the 3CCD receiver. After the polychromatic light passes through the beam-splitting assembly, the light of the three beam-splitting bands is emitted from the emission surface of the beam-splitting assembly in a horizontal or vertical direction.

[0023] The imaging lens assembly has a first optical structure design configured to compensate for aberrations introduced by the beam splitter during optical path transmission between the imaging lens and the 3CCD receiver.

[0024] Further,

[0025] The beam splitter assembly includes a cascaded first beam splitter and a second beam splitter.

[0026] The first beam splitter is used to split the incident light into a first band and a second band, wherein the first band is emitted in the emission direction at the first position and the second band is incident on the second beam splitter.

[0027] The second beam splitter is used to split the second band light into a third band and a fourth band. The third band is emitted in the emission direction at the second position, and the fourth band is emitted in the emission direction at the third position.

[0028] Further,

[0029] The first waveband has a first optical path length in the direction of emission from the first position.

[0030] The third band has a second optical path in the direction of emission from the second position.

[0031] The fourth band has a third optical path in the direction of emission from the third position.

[0032] The first optical path, the second optical path, and the third optical path are the same.

[0033] Further,

[0034] The first and second beam-splitting elements are cubic prisms with a 45° angled coated beam splitter.

[0035] In summary, compared with the prior art, the above technical solutions conceived by this utility model can achieve the following beneficial effects:

[0036] The multi-CCD imaging device implemented according to this utility model, since the above-mentioned beam-splitting component is applied in the multi-CCD imaging device, the added beam-splitting element generates multiple aberrations in the imaging optical path using a conventional lens. According to this utility model, the imaging lens is configured to be optically designed and optimized according to the overall optical path of the above-mentioned beam-splitting component, compensating for the aberrations caused by the introduction of the beam-splitting prism, and greatly improving the optical imaging quality.

[0037] The multi-CCD imaging device implemented according to this utility model performs preliminary wavelength selective spectral splitting, so that the spectral beams from the exit surface are emitted at approximately 0 degrees. Then, different end-face coatings are used to filter and reduce crosstalk. The device has high resolution, low spectral energy loss, and requires a shorter exposure time. It is particularly suitable for low-brightness measurement scenarios and has low crosstalk between colors. Attached Figure Description

[0038] Figure 1 This is a structural diagram showing the specific composition of the first-stage beam splitting component in the beam splitting assembly of the multi-CCD imaging device implemented according to this utility model;

[0039] Figure 2 This is a structural diagram showing the specific composition of the second-stage beam splitting component in the beam splitting assembly of the multi-CCD imaging device implemented according to this utility model;

[0040] Figure 3 This diagram illustrates a specific implementation of a beam splitting assembly according to the present invention, in which the first-stage beam splitting and the second-stage beam splitting are combined in a first manner to form three emission positions.

[0041] Figure 4 This is a schematic diagram of the specific structure of the beam-splitting component in the multi-CCD imaging device implemented according to this utility model. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0043] According to the concept of this utility model, a multi-CCD imaging device is proposed, which includes a beam splitting component, an imaging lens component, and a multi-CCD receiving device.

[0044] The imaging lens assembly, beam splitter assembly, and multi-CCD receiver are connected in sequence.

[0045] The imaging lens assembly guides the imaging polychromatic light to the beam splitter. The beam splitter has a certain thickness between the imaging lens assembly and the multi-CCD receiver. In this invention, the thickness generally refers to optical devices with relatively flat exit surfaces, such as cubic prisms, so that the exit image surface of the beam splitter is incident at approximately 0°. On the other hand, after the imaging polychromatic light passes through the beam splitter, light of different wavelengths exits from the exit surface of the beam splitter in a horizontal or vertical direction. At this time, the effect of filtering stray light is better. However, the light path of such a planar exit surface has higher aberrations. The multi-CCD receiver is set at the corresponding position of the exit direction at different positions of the beam splitter to receive light of the corresponding wavelength.

[0046] Therefore, in the multi-CCD imaging device corresponding to this utility model, the imaging lens assembly has a first optical structure design, which is configured to compensate for the aberrations introduced by the beam splitter in the optical path transmission between the imaging lens and the multi-CCD receiving device.

[0047] The imaging lens assembly, with its primary optical structure design, can be a packaged, integrated optical system. The assembly includes multiple optical elements, all functioning as an imaging lens. During simulated optical design, the beam-splitter is designed as part of the imaging lens group. This allows for the adjustment of parameters or components within the imaging lens group to compensate for aberrations introduced by the beam-splitter, minimizing overall imaging system aberrations and achieving higher image quality – thus achieving an optimal optical lens design. In production, the imaging lens without the beam-splitter is manufactured separately. It's understood that the resulting imaging lens differs from a standard imaging lens. Without the beam-splitter at the rear end of the imaging lens, poor image quality is achieved; conversely, adding the beam-splitter at the rear end results in high-definition imaging. In practical applications, if beam splitting is not required, simply replacing the beam-splitter prism with a glass material of equal optical path length is sufficient.

[0048] The beam-splitting component in this invention includes:

[0049] A beam splitting element group is used to split incident light into at least two bands, with each band of light being split to different exit directions; for example, the RGB bands of polychromatic light are first divided into R and GB, and R and GB are emitted at different beam splitting positions.

[0050] Preferably, the beam splitter group is composed of multiple beam splitters cascaded together. The beam splitter group is a slanted beam splitter with reflection and transmission of wavelengths, so that the wavelengths are guided to different exit directions and positions.

[0051] A filter element group, disposed in at least one direction of the emission direction, is configured to filter out other wavelengths of light corresponding to the emission direction band. Alternatively, it can be disposed in each emission direction at different locations to reduce stray light in each emission direction band.

[0052] The design of the filtering function enables those skilled in the art to develop and design based on the optical band filtering function.

[0053] For example, a filter element group is a coated layer, disposed as an inner or outer layer on a beam splitter located in the emission direction; or, a filter element group is a filter surface, disposed in the optical path outside the emission direction of the beam splitter group. The filter surface is a filter separately disposed in the optical path, or integrated into a receiving device (such as...). Figure 4 The front side of sensor 1, sensor 2, and sensor 3 shown in the diagram.

[0054] As a further feature of the embodiment, the filter surface is provided with a coating layer, which is disposed in the inner or outer layer at the incident position, or in the inner or outer layer at the exit position. In this case, the multi-level filtering effect further reduces stray light.

[0055] Specifically, the beam-splitting element group includes a cascaded first beam-splitting element and a second beam-splitting element.

[0056] The first beam splitter is used to split the incident light into a first band and a second band. The first band is emitted in the emission direction at the first position, and the second band is incident on the second beam splitter.

[0057] The second beam splitter is used to split the second band light into the third band and the fourth band. The third band is emitted in the emission direction at the second position, and the fourth band is emitted in the emission direction at the third position.

[0058] The first band has a first optical path length in the direction of emission from the first position, the third band has a second optical path length in the direction of emission from the second position, and the fourth band has a third optical path length in the direction of emission from the third position. The first, second, and third optical paths are the same. The first and second beam-splitting elements are 45° angled coated beam-splitters.

[0059] like Figure 1 The diagram shown is a structural schematic of a specific embodiment of the beam-splitting component in the multi-CCD imaging device of this utility model, specifically as follows:

[0060] Beam splitter 1 has a 45° beam-splitting slope. Polychromatic light emitted from the object passes through the imaging lens and then enters the beam splitter assembly. The first slope of beam splitter 1 reflects most of the B rays and transmits the RG rays. The reflected B rays and a small portion of the RG rays enter the first bottom cubic prism of the beam splitter assembly.

[0061] Since the B ray and a small portion of the RG ray after passing through beam splitter 1 have an incident angle of approximately 0 degrees in the optical path, the incident angle of the B ray is essentially 0 degrees.

[0062] At this time, in the direction of B-ray emission, a coating layer is used as a filter element group. This coating layer is set inside or outside the emission surface of the beam splitter 1, or inside or outside the emission surface of the first bottom cubic prism, or in the optical path after the emission of the first bottom cubic prism, a filter is further set. The filter itself is made of filter material, or has an inner or outer coating layer. It allows B-ray to pass through, reflects a small portion of the light, and filters out other light rays, including RG-ray, except for the B-band, so as to eliminate stray light emitted by B-ray and achieve higher resolution in the subsequent multi-color light combining.

[0063] like Figure 2 As shown, the RG light transmitted after beam splitter 1 passes through beam splitter 2, which has a second inclined surface to further split the RG light into R light and G light. The inclined surface coating of beam splitter 2 causes R to be reflected and G to be transmitted (or R to be transmitted and G to be reflected).

[0064] For the reflected R rays, they will contain some G light energy and a very small amount of B light energy. Similarly, the coating layer is used as a filter element group. The coating layer is set inside or outside the exit surface of the two beams of the beam splitter 2, or a filter is further set in the light path after the beams are emitted in one direction of the beam splitter 2. The filter itself is made of filter material or has an inner or outer coating layer. At the same time, another filter is further set in the light path after the beams are emitted in the other direction of the beam splitter 2. The filter itself is made of filter material or has an inner or outer coating layer.

[0065] Compared to traditional 3CCD beam splitting, the beam splitting component of this invention employs a combined coating method to achieve excellent RGB light splitting performance. Generally, when beam splitting is performed at a 45° angle, the coating curve rises slowly, leading to impure beam splitting purity. Specifically, ideally, at the first angled beam splitting, theoretically all B-beams should be reflected and all RG-beams should be transmitted. However, due to the 45° incident angle, only most B-beams are reflected, and a small portion of RG-beams are also reflected, causing significant crosstalk in multi-CCD imaging. By applying a supplementary coating layer at the exit face of the reflecting prism, most light rays have an incident angle close to 0°, ensuring that B-beams are transmitted while RG-beams are completely reflected, thus reducing crosstalk and improving the resolution of multi-CCD imaging.

[0066] like Figure 3The diagram shows the combined application of the beam-splitting component according to this utility model in a three-color beam splitting. In this case, beam-splitting prism 1, beam-splitting prism 2, and cubic prism are arranged in a certain combination. Beam-splitting prisms 1 and 2 are both composed of two isosceles right-angled triangular prisms spliced ​​together. The hypotenuse of one of the isosceles right-angled triangular prisms is coated, so that the generated RGB beam splitting is split at different exit surface positions in the combined beam-splitting component. Different light bands are combined with filter layers in the optical path of different light bands to filter out light of other bands other than the current exit band as much as possible. At this time, beam-splitting prisms 1 and 2 and cubic prism are all made of flat glass. Figure 3 The image shown is just one way to set up a beam splitter; other methods could also be used. Figure 3 The two adjacent isosceles right triangles of the splitting prism 1 and 2 are combined to form a larger isosceles right triangle. Coatings are applied to the two right-angled sides of this larger isosceles right triangle, and right-angled prisms or trapezoidal prisms are added to the remaining positions. This can achieve a similar effect. Figure 3 The optical path is shown. Therefore, the optical path formed here is as follows. Figure 3 The combination of prisms in the optical path shown is not limited.

[0067] In other embodiments, for example, to separate light into more wavelengths, it becomes a pentaprism, a beam-splitting system with multiple exit surfaces.

[0068] Although flat glass has a simple structure, its influence on the optical path is not negligible. Flat glass introduces aberrations into imaging optical systems, and if flat glass is directly inserted into the existing camera optical path, the image quality will be very low. Figure 4 The diagram illustrates a specific application of the beam-splitting component according to this invention in a 3CCD imaging scenario. In this case, the beam-splitting component is positioned behind a camera lens. Light rays, after being focused by the imaging lens, are split into three wavelength bands at three exit positions: red, blue, and green. Behind each exit surface, a sensor array corresponding to the respective wavelength band is positioned to receive and analyze the imaging information of that band. The beam-splitting component has multiple exit and incident surfaces (a, b, c, d, e, f, g, h) in its optical path. In the optical path design of this beam-splitting element, the design of the 3CCD camera lens needs to consider the aberrations caused by the addition of prisms 1, 2, and 3 (i.e., flat glass). The thickness and refractive index of the flat glass directly affect the magnitude of the aberrations. In the design of the imaging device itself, the lens is designed to eliminate the aberration changes caused by the beam-splitting element. Specifically, during the simulation design of the lens, a flat glass plate can be added. The thickness and refractive index of the flat glass plate can be determined according to actual needs, thereby optimizing the lens design. By changing the optical components or parameters of the lens assembly in the simulation, the phase difference after adding the flat glass plate can be minimized.

[0069] According to some embodiments of this utility model, some of the main application scenarios include:

[0070] Broadcasting and film production: In the fields of broadcasting and film production, 3CCD cameras are often used to capture high-quality images to ensure color accuracy and image clarity.

[0071] Medical Imaging: In the medical field, 3CCD cameras can be used to capture medical images, such as surgical procedure recordings and pathological images. High color fidelity and image quality can help doctors make more accurate diagnoses.

[0072] Industrial Vision: In the industrial field, 3CCD cameras can be used for quality control, inspection and measurement applications, especially in scenarios with high requirements for color and detail, such as print quality inspection and electronic component inspection.

[0073] Scientific Research: In the field of scientific research, 3CCD cameras are often used to capture experimental data, Earth observation, astronomical observation and other images that require high resolution and color accuracy.

[0074] Education and Training: In the field of education and training, 3CCD cameras can be used to create instructional videos, training materials, etc., to provide clear and accurate images to students and trainers.

[0075] The description in this specification is merely an illustrative example of the present invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the content of this specification or exceed the scope defined in the claims, they shall all fall within the protection scope of this invention.

Claims

1. A multi-CCD imaging device, characterized in that, The multi-CCD imaging device includes a beam splitter assembly, an imaging lens assembly, and a multi-CCD receiver. The imaging lens assembly, beam splitter assembly, and multi-CCD receiver are connected in sequence. The imaging lens assembly guides the imaging polychromatic light to the beam splitter. The beam splitter has a certain thickness between the imaging lens assembly and the multi-CCD receiver. The multi-CCD receiver is positioned at corresponding positions in the emission direction of different positions of the beam splitter to receive light of the corresponding wavelength band. The imaging lens assembly has a first optical structure design configured to compensate for aberrations introduced by the beam splitter during optical path transmission between the imaging lens assembly and the multi-CCD receiver.

2. The multi-CCD imaging device as described in claim 1, characterized in that, The beam splitter has a certain planar thickness between the imaging lens assembly and the multi-CCD receiver. After the imaging polychromatic light passes through the beam splitter, light of different wavelengths is emitted from the exit surface of the beam splitter in a horizontal or vertical direction.

3. The multi-CCD imaging device as described in claim 1 or 2, characterized in that, The beam splitting assembly includes: a beam splitting element group for splitting incident light into at least two wavelengths, wherein the light of each wavelength is split to an outgoing direction at a different location, and the optical path of the light of each wavelength is equal; and a filter element group disposed in at least one direction of the outgoing direction and configured to filter out other wavelengths of light corresponding to the outgoing direction wavelength.

4. The multi-CCD imaging device as described in claim 3, characterized in that, The beam-splitting element in the beam-splitting element group is a cubic prism with a 45° angled coated beam splitter having a certain planar thickness.

5. The multi-CCD imaging device as described in claim 3, characterized in that, The filter element group is a coating layer, which is an inner or outer layer disposed on the beam splitter at a position in the emission direction; or, the filter element group is a filter surface disposed in the optical path outside the position in the emission direction of the beam splitter group.

6. The multi-CCD imaging device as described in claim 5, characterized in that, The filter surface is a filter separately set in the optical path, or integrated on the front side of the multi-CCD receiving device.

7. A 3CCD imaging device, characterized in that, The 3CCD imaging device includes a beam splitter assembly, an imaging lens assembly, and a 3CCD receiver. The imaging lens assembly, beam splitter assembly, and 3CCD receiver are connected in sequence. The imaging lens assembly guides the imaging polychromatic light to the beam-splitting assembly. The 3CCD receiver is positioned at three different positions on the beam-splitting assembly corresponding to the emission directions, respectively receiving the RGB band light that has been split. The beam-splitting assembly has a certain planar thickness between the corresponding positions of the three beam-splitting bands of the imaging lens assembly and the 3CCD receiver. After the polychromatic light passes through the beam-splitting assembly, the light of the three beam-splitting bands is emitted from the emission surface of the beam-splitting assembly in a horizontal or vertical direction. The imaging lens assembly has a first optical structure design configured to compensate for aberrations introduced by the beam splitter during optical path transmission between the imaging lens and the 3CCD receiver.

8. The 3CCD imaging device as described in claim 7, characterized in that, The beam splitting assembly includes a beam splitting element group, which includes a cascaded first beam splitting element and a second beam splitting element. The first beam splitter is used to split the incident light into a first band and a second band, wherein the first band is emitted in the first position emission direction and the second band is incident on the second beam splitter. The second beam splitter is used to split the second band light into a third band and a fourth band. The third band is emitted in the emission direction at the second position, and the fourth band is emitted in the emission direction at the third position.

9. The 3CCD imaging device as described in claim 8, characterized in that, The first waveband has a first optical path length in the direction of emission from the first position. The third band has a second optical path in the direction of emission from the second position. The fourth band has a third optical path in the direction of emission from the third position. The first optical path, the second optical path, and the third optical path are the same.

10. The 3CCD imaging device as described in claim 8, characterized in that, The first beam splitter and the second beam splitter are cubic prisms with a 45° angled coated beam splitter.

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