Color separation prism optical system and camera device

Abstract

The embodiment of the invention provides a color separation prism optical system and a camera device, the color separation prism optical system comprises a pre-processing module and a color separation module, the pre-processing module is used for carrying out filtering and shaping pre-processing on incident light to obtain light beams to be subjected to color separation; the color separation module at least comprises a first color separation prism, a second color separation prism and a third color separation prism, the first surface of the first color separation prism is vertically arranged, the third surface of the first color separation prism and the second color separation prism are arranged at an air interval, and the first color separation prism, the second color separation prism and the third color separation prism carry out light splitting treatment on light beams to be subjected to color separation; light beams of different colors are output from the first color separation prism, the second color separation prism and the third color separation prism, incident light is decomposed into blue light, red light and green light through the color separation prism optical system, all monochromatic light has high light transmittance, the influence of stray light of the system on the imaging quality can be effectively reduced, and the light splitting accuracy can be guaranteed.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to a color separation prism optical system and a camera device. Background Art

[0002] The optical imaging system is an important component of the camera device. The optical system in the lens converts the light signal of the captured image into an electrical signal through the image sensor, and the final image is formed after signal processing. The quality of image capture is directly related to the imaging quality of the optical system in the camera.

[0003] There are two commonly used methods for the optical imaging system in the camera device. One commonly used optical imaging method in the camera device is through the Bayer color separation pattern, which is a mosaic color filter array formed by arranging RGB filters on the grid of the light sensing system. Because the arrangement of the filters in the Bayer color separation pattern is 50% green, 25% red and 25% blue, it is also called RGBG, GRGB or RGGB. Since the Bayer color separation pattern uses a color interpolation method, that is, each pixel can only capture one color, it is necessary to estimate the other two colors through algorithm interpolation. The principle diagram is as follows Figure 1 shown.

[0004] Another method in the camera device is to decompose the incident light into blue light, red light and green light through a color separation prism and the propagation characteristics of light. The decomposed color light components will enter the corresponding image sensor imaging element. This color separation prism optical system is called a Philips prism optical system. For the method of using the Bayer color separation mode for imaging in the camera, due to the color interpolation problem of the Bayer color separation mode, that is, each pixel can only capture one color, it is necessary to estimate the other two colors through software interpolation, which will lead to inaccurate colors, moire fringes and color artifacts; the interpolation process will reduce the effective resolution of the camera and affect the clarity of image details. According to the survey, in the previous optical prism system, after the light is split by the prism, the transmittance of each color light is quite different, resulting in deviation in the color reproducibility of the picture in the camera device; for the light waves of other bands that are still propagated to the image sensor after the prism split, the sensitivity of the camera device is reduced. Therefore, how to improve the spectral transmittance, color separation accuracy and high-quality imaging of the optical system in the camera device is an urgent problem to be solved. Summary of the invention

[0005] Some embodiments of the present application aim to provide a color separation prism optical system and a camera device. According to the technical solution of the embodiments of the present application, the color separation prism optical system includes: a preprocessing module and a color separation module, wherein the preprocessing module is used to filter and shape the incident light to obtain a light beam to be separated; the color separation module at least includes a first color separation prism, a second color separation prism and a third color separation prism, the first surface of the first color separation prism is vertically arranged, and an air gap is maintained between the third surface of the first color separation prism and the second color separation prism. The first color separation prism, the second color separation prism and the third color separation prism are arranged at intervals, the second surface of the second color separation prism is arranged in contact with the third color separation prism, the first color separation prism, the second color separation prism and the third color separation prism perform light separation processing on the light beam to be separated, and light beams of different colors are output from the first color separation prism, the second color separation prism and the third color separation prism. Through the color separation prism optical system of the present application, the incident light is decomposed into blue light, red light and green light, and each monochromatic light has a high transmittance, which can effectively reduce the influence of system stray light on imaging quality and ensure the accuracy of light separation.

[0006] In a first aspect, some embodiments of the present application provide a color separation prism optical system, comprising: a preprocessing module and a color separation module, wherein the preprocessing module is used to filter and shape the incident light to obtain a light beam to be color separated; The color separation module at least includes a first color separation prism, a second color separation prism and a third color separation prism, the first surface of the first color separation prism is vertically arranged, the third surface of the first color separation prism and the second color separation prism are arranged with an air gap, the second surface of the second color separation prism is arranged in contact with the third color separation prism, the first color separation prism, the second color separation prism and the third color separation prism perform light separation processing on the light beam to be color separated, and output light beams of different colors from the first color separation prism, the second color separation prism and the third color separation prism.

[0007] Some embodiments of the present application can reduce reflections between optical elements by coating the surfaces of each optical element in contact with the air with an anti-reflection film layer, thereby ultimately reducing the impact of ghost glare caused by stray light on imaging of the optical system.

[0008] Some embodiments of the present application can effectively reduce the impact of system stray light on imaging quality and ensure the accuracy of spectrometry by decomposing incident light into blue light, red light, and green light, and each monochromatic light has a high transmittance.

[0009] Optionally, the first surface of the first color separation prism is used to input the light beam to be color separated, and the third surface of the first color separation prism is coated with a color separation film, and the color separation film has the characteristics of being able to reflect blue light and allow red light and green light to pass through. The third surface of the first color separation prism is used to reflect the blue light in the light beam to be color separated to the first surface of the first color separation prism, and the blue light is totally reflected on the first surface of the first color separation prism, and the reflected blue light is vertically transmitted out of the prism through the second surface of the first color separation prism.

[0010] In some embodiments of the present application, a first color separation prism is provided to separate the blue light in the light beam to be separated, and the obtained blue light is transmitted through the second surface of the first color separation prism.

[0011] Optionally, the reflection condition for the first surface of the first dichroic prism to totally reflect the blue light is: The first total reflection angle is n times the included angle between the first surface and the first prism of the third surface of the first dichroic prism, where n is a natural number greater than 1. Optionally, the light beam to be separated is transmitted through the third surface of the first color separation prism to obtain red light in the light beam to be separated, and the first surface of the second color separation prism is used to receive the red light, and the red light in the separated light beam thereby enters the second color separation prism for transmission, and a color separation film is coated on the second surface of the second color separation prism, and the color separation film has the characteristic of reflecting red light and allowing green light to be transmitted, and the second surface of the second color separation prism is used to reflect the red light to the first surface of the second color separation prism, and the red light is totally reflected on the first surface of the second color separation prism, and the reflected red light is vertically transmitted out of the prism through the third surface of the second color separation prism.

[0012] In some embodiments of the present application, the red light in the color separation light beam is transmitted through the first color separation prism, and then reflected and totally reflected by the second color separation prism, and finally the red light is vertically emitted from the third surface of the second color separation prism.

[0013] Optionally, the reflection condition for the first surface of the second dichroic prism to totally reflect the red light is: The second total reflection angle is determined according to the first prism angle and the second prism angle, wherein the second prism angle is the angle between the first surface and the second surface of the second color separation prism.

[0014] Optionally, the second total reflection angle is determined according to the first prism angle and the second prism angle, including: θ2=2γ-α, wherein θ2 is the second total reflection angle, γ is the second prism angle, and α is the first prism angle.

[0015] Optionally, the dichroic films of the first dichroic prism and the second dichroic prism both allow green light to be transmitted, and the green light in the light beam to be separated is transmitted through the first and third surfaces of the first dichroic prism into the second dichroic prism, is transmitted through the first and second surfaces of the second dichroic prism into the third prism, and is vertically transmitted through the third prism to obtain green light.

[0016] In some embodiments of the present application, green light is allowed to be transmitted through the first dichroic prism and the second dichroic prism, and finally transmitted vertically through the third dichroic prism.

[0017] Optionally, the pre-processing module comprises at least a UV / IR cut-off filter, a color compensation filter, a neutral grayscale filter and a collimating lens, wherein: The UV / IR cutoff filter is used to filter the ultraviolet light waves and infrared light waves in the incident light; The color compensation filter is used to perform color correction compensation on the incident light; The neutral gray mirror is used to control the intensity of the incident light wave; The collimator is used to shape the incident light and convert the incident light into parallel light or quasi-parallel light.

[0018] In some embodiments of the present application, a preprocessing module is provided, through which the light beam to be separated is filtered and shaped preprocessed, and light waves outside the visible light band of the incident light can be filtered out. The incident light can be subjected to color correction compensation and light intensity regulation, so as to obtain a processed light beam to be separated, thereby improving the quality of the incident light entering the color separation prism.

[0019] Optionally, the color separation prism optical system comprises at least a first filter, a second filter and a third filter; Wherein, the first filter is connected to the second surface of the first color separation prism; The second filter is connected to the third surface of the second color separation prism; The third filter is connected to the third color separation prism.

[0020] In some embodiments of the present application, because the dichroic film coated on a specific surface of the dichroic prism is not 100% fully transmissive within the allowed transmission light band, a small amount of transmitted light waves will still be reflected. These reflected transmitted light waves will mix with other color light waves and finally be emitted from other light channels, thereby reducing color reproducibility and causing ghosting and glare. In order to eliminate the residual transmitted light waves and prevent ghosting and glare, corresponding filters are configured at the light outlet of each dichroic prism to improve color reproducibility.

[0021] In a second aspect, some embodiments of the present application provide a camera device, comprising at least the color separation prism optical system described in the first aspect, wherein the color separation prism optical system decomposes incident light into blue light, red light, and green light, which are then transmitted to different image sensors, and images are obtained through signal processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of some embodiments of the present application, the drawings required for use in some embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is the principle diagram of the Bayer color separation mode of the prior art; Figure 2 A schematic diagram of the structure of a color separation prism optical system provided in an embodiment of the present application; Figure 3 A schematic diagram of the optical path of a color separation prism provided in an embodiment of the present application; Figure 4 A schematic diagram of the relationship between the angles of various light rays in the dichroic prism provided in an embodiment of the present application; Figure 5 This is a graph showing the spectral transmittance characteristic of the color separation optical prism system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The technical solutions in some embodiments of the present application will be described below in conjunction with the drawings in some embodiments of the present application.

[0025] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0026] The optical imaging system is an important component of the camera device. The optical system in the lens converts the light signal of the captured image into an electrical signal through the image sensor, and the final image is formed after signal processing. The quality of image capture is directly related to the imaging quality of the optical system in the camera.

[0027] There are two commonly used methods for the optical imaging system in the camera device. One commonly used optical imaging method in the camera device is through the Bayer color separation pattern, which is a mosaic color filter array formed by arranging RGB filters on the grid of the light sensing system. Because the arrangement of the filters in the Bayer color separation pattern is 50% green, 25% red and 25% blue, it is also called RGBG, GRGB or RGGB. Since the Bayer color separation pattern uses a color interpolation method, that is, each pixel can only capture one color, it is necessary to estimate the other two colors through algorithm interpolation. The principle diagram is as follows Figure 1 shown.

[0028] Another method in the camera device is to decompose the incident light into blue light, red light and green light through a color separation prism and the propagation characteristics of light. The decomposed color light components will enter the corresponding image sensor imaging element. This color separation prism optical system is called a Philips prism optical system. For the method of using the Bayer color separation mode for imaging in the camera, due to the color interpolation problem of the Bayer color separation mode, that is, each pixel can only capture one color, it is necessary to estimate the other two colors through software interpolation, which will result in inaccurate colors, and moiré fringes and color artifacts will appear; the interpolation process will reduce the effective resolution of the camera and affect the clarity of the image details. According to the investigation, in the previous optical prism system, after the light is split by the prism, the transmittance of each color light is quite different, which leads to the deviation of the color reproducibility of the picture in the camera device; after the light is split by the prism, there are still light waves in other bands that propagate to the image sensor, which leads to the decrease of the sensitivity of the camera device. Therefore, how to improve the spectral transmittance, color separation accuracy and high-quality imaging of the optical system in the camera device is an urgent problem to be solved. In view of this, some embodiments of the present application provide a color separation prism optical system, which includes: a preprocessing module and a color separation module, wherein the preprocessing module is used to filter and shape the incident light to obtain a light beam to be separated; the color separation module The block at least includes a first color separation prism, a second color separation prism and a third color separation prism. The first surface of the first color separation prism is vertically arranged, the third surface of the first color separation prism is arranged with an air gap between the second color separation prism, the second surface of the second color separation prism is arranged in contact with the third color separation prism, the first color separation prism, the second color separation prism and the third color separation prism perform light separation processing on the color separation light beam, and light beams of different colors are output from the first color separation prism, the second color separation prism and the third color separation prism. Through the color separation prism optical system of the present application, the incident light is decomposed into blue light, red light and green light, and each monochromatic light has a high transmittance, which can effectively reduce the influence of system stray light on imaging quality and ensure the accuracy of light separation.

[0029] like Figure 2As shown, an embodiment of the present application provides a color separation prism optical system, which includes: a preprocessing module and a color separation module, wherein the preprocessing module is used to filter and shape the incident light to obtain a light beam to be separated.

[0030] The color separation module at least includes a first color separation prism 5, a second color separation prism 6 and a third color separation prism 7. The first surface of the first color separation prism is vertically arranged, the third surface of the first color separation prism is arranged with an air gap between the second color separation prism, the second surface of the second color separation prism is arranged in contact with the third color separation prism, the first color separation prism, the second color separation prism and the third color separation prism perform light separation processing on the light beam to be separated, and light beams of different colors are output from the first color separation prism, the second color separation prism and the third color separation prism.

[0031] Specifically, in order to improve the sensitivity of the camera device, the dichroic film in the dichroic prism optical system should have a relatively steep slope and a wide bandwidth characteristic for transmitting / reflecting monochromatic light. On the other hand, in order to ensure that the sensitivity of the camera device is close to the spectroscopic sensitivity characteristics of the human eye, the imaging element is also sensitive to infrared light that is usually not perceived by the human eye. Therefore, in order to cut off the infrared light and obtain the spectroscopic sensitivity characteristics close to the human eye, it is necessary to set a filter to filter and cut off the infrared light before the dichroic prism, that is, the pre-processing module already includes this function.

[0032] The incident light is filtered and shaped by the preprocessing module to obtain a light beam to be separated. The color separation module at least includes a first color separation prism, a second color separation prism and a third color separation prism. The first surface of the first color separation prism is vertically arranged, the third surface of the first color separation prism is arranged with an air gap between the second color separation prism, the second surface of the second color separation prism is arranged in contact with the third color separation prism, the first color separation prism, the second color separation prism and the third color separation prism perform light separation processing on the light beam to be separated, and light beams of different colors are output from the first color separation prism, the second color separation prism and the third color separation prism.

[0033] In some embodiments of the present application, the surfaces of each optical element in contact with the air are coated with an anti-reflection film layer, which can reduce reflections between optical elements and ultimately reduce the impact of ghost glare caused by stray light on the imaging of the optical system.

[0034] Some embodiments of the present application can effectively reduce the impact of system stray light on imaging quality and ensure the accuracy of spectrometry by decomposing incident light into blue light, red light, and green light, and each monochromatic light has a high transmittance.

[0035] Another embodiment of the present application further supplements the color separation prism optical system provided by the above embodiment.

[0036] like Figure 3As shown, the color separation prism optical system provided in the embodiment of the present application decomposes the incident light into three light paths of blue light, red light, and green light for propagation.

[0037] The core dichroic prism assembly is composed of three prisms of different sizes. First, the (5-3) reflection / transmission surface of prism 5 is coated with a dichroic film layer that reflects the multi-band characteristics of light from the long wavelength side of the blue light and red light region to the infrared region and allows red light and green light to be transmitted; the (6-2) reflection / transmission surface of prism 6 is coated with a dichroic film layer that reflects red light and allows green light to be transmitted; an air gap is left between prism 5 and prism 6. This creates conditions for the total reflection of light waves on the (6-1) surface of prism 6. However, the width of the air gap only needs to meet the requirements of light path propagation and should not be too wide, so as to reduce the optical path and ambient light entering the optical system and minimize the impact on the imaging quality of the optical system. Prism 6 and prism 7 are bonded together.

[0038] Optionally, the first surface of the first color separation prism is used to input the light beam to be separated, and the third surface of the first color separation prism is used to reflect the blue light in the light beam to be separated to the first surface of the first color separation prism, and the blue light is totally reflected on the first surface of the first color separation prism, and the reflected blue light is vertically transmitted out of the prism through the second surface of the first color separation prism.

[0039] The third surface of the first dichroic prism is coated with a dichroic film, and the dichroic film has the characteristic of reflecting blue light and allowing red light and green light to pass through.

[0040] Specifically, the incident light enters the prism vertically through the (5-1) surface of the prism 5, and the light wave propagates to the (5-3) surface of the prism 5. Since the (5-3) surface of the prism 5 is coated with a dichroic film that reflects blue light and allows red light and green light to pass through, the blue light is reflected to the (5-1) surface of the prism 5, and is totally reflected on the (5-1) surface, and then vertically transmitted through the (5-2) surface of the prism 5.

[0041] Some embodiments of the present application separate the blue light in the light beam to be separated by providing a first color separation prism, and transmit the obtained blue light through the third surface of the first color separation prism.

[0042] Optionally, the reflection condition for the first surface of the first dichroic prism to totally reflect the blue light is: The first total reflection angle is n times the included angle between the first surface and the third surface of the first dichroic prism, wherein n is a natural number greater than 1, and θ1 is the first total reflection angle.

[0043] For example: θ1=2α, blue light satisfies total reflection; in the embodiment of the present application, n can be 2.

[0044] Optionally, the red light in the light beam to be separated is transmitted through the third surface of the first color separation prism, and the separated light beam enters the second color separation prism for transmission. The second surface of the second color separation prism is coated with a color separation film, and the color separation film has the characteristics of reflecting red light and allowing green light to be transmitted. The second surface of the second color separation prism is used to reflect the red light to the first surface of the second color separation prism. The red light is totally reflected on the first surface of the second color separation prism, and the reflected red light is vertically transmitted out of the prism through the third surface of the second color separation prism.

[0045] The color-separated light beam then enters the second color-separating prism for transmission. A color-separating film is coated on the second surface of the second color-separating prism. The color-separating film has the characteristic of reflecting red light and allowing green light to be transmitted.

[0046] Specifically, for red light, since the dichroic film layer of prism 5 allows red light to pass through, the red light is incident through the (6-1) surface of prism 6, and passes through the (6-2) surface of prism 6 coated with a dichroic film layer that reflects red light. Therefore, the red light is reflected to the (6-1) surface and is totally reflected on the surface, and finally is vertically transmitted through the (6-3) surface; In some embodiments of the present application, the red light in the light beam to be separated is transmitted through the first color separation prism, then reflected and totally reflected by the second color separation prism, and then the red light is transmitted from the third surface of the second color separation prism. Optionally, the reflection condition for the first surface of the second dichroic prism to totally reflect the red light is: The second total reflection angle is determined according to the first prism angle and the second prism angle, wherein the second prism angle is the angle between the first surface and the second surface of the second color separation prism.

[0047] Optionally, the second total reflection angle is determined according to the first prism angle and the second prism angle, including: θ2=2γ-α, where θ2 is the second total reflection angle, γ is the second prism angle, and α is the first prism angle.

[0048] Specifically, in order to realize the above-mentioned split beam propagation of the incident light in the prism, an air gap must be left between the prism 5 and the prism 6 to ensure that the light is totally reflected on the designated surface. The light transmission path and the prism must meet a certain angle relationship, such as Figure 4 As shown, θ1=2α, blue light satisfies total reflection; θ2=2γ-α, red light satisfies total reflection; it is ensured that all colored lights separated by the prism are vertically transmitted out of the prism. The optical paths of the three optical paths remain equal. According to the optical path design, the angle between the horizontal optical axis of the blue light separated by the prism is 53°, and the angle between the red light separated by the prism and the horizontal optical axis is 79.5°. Both blue light and red light are reflected twice in the prism, which ensures that their imaging is similar to the object, avoids the result of mirroring, and saves the functional configuration for image inversion.

[0049] Optionally, the green light in the light beam to be separated is transmitted through the first and third surfaces of the first separation prism into the second separation prism, transmitted through the first and second surfaces of the second separation prism into the third prism, and vertically transmitted through the third prism to obtain green light.

[0050] Specifically, since the dichroic films coated on the designated surfaces of prism 5 and prism 6 can allow the transmission of green light, the green light in the light beam to be dichroic passes through the incident surface (5-1), reflection and transmission surface (5-3) of prism 5, the incident surface (6-1), reflection and transmission surface (6-2) of prism 6, and finally is vertically transmitted through the surface (7-1) of prism 7.

[0051] In some embodiments of the present application, the green light in the light beam to be separated passes through the first dichroic prism and the second dichroic prism, allowing the green light to be transmitted, and finally vertically transmitted through the third dichroic prism.

[0052] Optionally, the pre-processing module at least includes a UV / IR cut-off filter 1, a color compensation filter 2, a neutral grayscale mirror 3 and a collimating mirror 4, wherein: The UV / IR cutoff filter is used to filter the ultraviolet light waves and infrared light waves in the incident light; The color compensation filter is used to perform color correction compensation on the incident light; The neutral gray mirror is used to control the intensity of the incident light wave; The collimator is used to shape the incident light and convert the incident light into parallel light or quasi-parallel light.

[0053] Specifically, Figure 2 As shown in the figure, the color separation prism optical system is composed of different optical components from left to right, which are UV / IR cut-off filters, which cut off and filter out ultraviolet / infrared band light waves, and only visible light passes; CC filter 2 (color compensation filter), which is mainly used to correct and adjust the color balance of the picture and enhance the artistic effect of the picture. The CC filter compensates for the color deviation in the picture by adjusting the density of different colors to ensure accurate color restoration; ND filter 3 (neutral gray filter), the main function is to reduce the light entering the camera lens, thereby controlling the amount of light entering the photosensitive element, and the light attenuation ability of different bands is equally uniform; collimator 4, which shapes the light beam and turns the light beam into parallel light or quasi-parallel light.

[0054] Since the imaging element is also sensitive to ultraviolet light and infrared light that are usually imperceptible to the human eye, before the incident light enters the prism, the ultraviolet and infrared light waves are filtered out by the UV / IR cutoff filter set in front, and the light waves in the visible light band continue to propagate through the prism system, ensuring the imaging quality and avoiding the reduction of imaging quality due to the imaging element being able to accept light waves other than visible light, thereby being more in line with the sensitivity of the human eye and ensuring the sensitivity of the imaging device.

[0055] The color separation film layer of the beam splitter prism is not 100% fully transparent within the range of transmitted light waves, and a small amount of transmitted light waves will still be reflected. These residual transmitted light waves will mix with other color channel light waves, thereby reducing color reproducibility and causing ghosting and glare. In order to eliminate the residual transmitted light waves and prevent ghosting and glare, corresponding filters are configured at the exit position of each beam splitter prism to improve color reproducibility.

[0056] Furthermore, the shape and size of the dichroic prism in the present application are related to the usage scenario. The most important ones are: first, the angle design of the three prisms, the light transmission in the prism meets the total reflection condition; second, the air gap between the first dichroic prism and the second dichroic prism, cleverly utilizing the selective reflection and transmission of the two dichroic films, and utilizing the total reflection of the air gap to achieve three-color decomposition; third, making full use of the reflection, refraction and propagation characteristics of light waves to achieve splitting; fourth, the clever combination of various optical elements to ultimately achieve excellent splitting characteristics.

[0057] In some embodiments of the present application, a preprocessing module is provided, through which the light beam to be separated is filtered and shaped, infrared light and ultraviolet light in the incident light can be filtered out, and color correction compensation and light intensity regulation can be performed on the incident light, so as to obtain a processed light beam to be separated, thereby improving the quality of the incident light entering the color separation prism.

[0058] Optionally, the color separation prism optical system comprises at least a first filter, a second filter and a third filter; Wherein, the first filter is connected to the second surface of the first color separation prism; The second filter is connected to the third surface of the second dichroic prism; The third filter is connected to the third color separation prism.

[0059] Specifically, the core system color separation prisms, namely the first color separation prism 5, the second color separation prism 6 and the third color separation prism 7, work together to separate the incident light into blue light, red light and green light for propagation in separate light paths; filters 8, 9 and 10 are respectively placed at the light outlet positions of the prisms to filter out excess color light to improve color reproducibility.

[0060] That is, the third surface (5-3) of the first color separation prism 5 is connected to the filter 10, the third surface (6-3) of the second color separation prism is connected to the filter 9, and the (7-1) of the third color separation prism is connected to the filter 8.

[0061] In some embodiments of the present application, in order to eliminate residual transmitted light waves and prevent the generation of ghost glare, corresponding filters are arranged at the emission outlet of each dichroic prism to improve color reproducibility.

[0062] The dichroic film layers coated on prisms 5 and prism 6 are now analyzed and explained. The dichroic film layers coated on the surface (5-3) of prism 5 have a multi-band characteristic of reflecting light from the long wavelength side of the red region to the infrared region in addition to reflecting blue light. It has a bandpass filtering characteristic, which ensures that the infrared band light waves that are not completely filtered in front of the prism system are further filtered out, making the transmittance curve of the dichroic film layer closer to the spectral sensitivity characteristics of the human eye. Moreover, the sensitivity of the red light component is maintained at a high sensitivity close to the green light component through the spectral transmittance characteristics of the dichroic film layer of prism 5. For the dichroic film layer coated on the surface (6-2) of prism 6, as long as it is ensured that the red light is reflected and the green light is transmitted through Figure 5 It is the spectral transmittance characteristic curve of the color separation prism optical system.

[0063] from Figure 5 It can be concluded that the peak minimum value of the central wavelength transmittance of each monochromatic light is greater than 80%, and each monochromatic light maintains a transmittance of more than 80% in a large range. The transmittance of each monochromatic light is very close, which can ensure that each monochromatic light has a similar acceptable sensitivity. When the above optical prism system is used in the camera device for white balance adjustment operation, it can ensure that the sensitivity ratio is as close as possible to R: G: B = 1: 1: 1, which will reduce the gain of a certain monochromatic light, can greatly reduce the amplification of noise, and can suppress the S / N degradation less, and can ensure the color reproduction of the picture. The use of the above color separation optical prism system in broadcast-level camera devices can achieve excellent picture reproduction and reproducibility; the image resolution is significantly improved, and the image details are clearer; the ability to control light is stronger, and it is more adaptable to different shooting environments.

[0064] The color separation prism optical system provided in the embodiment of the present application has the following advantages: 1. The color separation prism optical system can separate the three colors of R, G, and B, and filter out the light waves of other colors, ensuring color accuracy; 2. The color separation prism optical system can achieve a three-color transmittance of R, G, and B of more than 80% and has a wide bandwidth band; 3. The dichroic prism optical system can effectively suppress stray light through ingenious design, reducing the impact of ghost images on imaging quality; 4. The color separation prism optical system is used in the camera device to ensure the color reproducibility and ensure that the optical imaging system has a high signal-to-noise ratio; It should be noted that each implementable method in this embodiment may be implemented separately, or may be implemented in combination in any combination without conflict, and this application is not limited thereto.

[0065] The embodiment of the present application provides a color separation prism optical system that can be used in a camera device, which decomposes the incident light into three light paths of R, G, and B for propagation. Each light path corresponds to a specific CMOS image sensor, and photoelectric conversion is realized on the image sensor. After signal processing, imaging can be achieved. The color separation prism optical system composed of different optical elements has the characteristics of high color separation accuracy, less system stray light, high spectral transmittance, and excellent color reproducibility. The color separation prism optical system in the embodiment of the present application can provide a color separation prism optical system with excellent color reproducibility and less influence of stray light components, less degradation of the S / N (signal-to-noise) ratio and excellent image quality, which can be used in broadcast-level camera devices.

[0066] The above are only embodiments of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0067] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0068] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A color separation prism optical system, characterized in that: The color separation prism optical system comprises: a preprocessing module and a color separation module, wherein the preprocessing module is used to filter and shape the incident light to obtain a light beam to be color separated; The color separation module at least includes a first color separation prism, a second color separation prism and a third color separation prism, the first surface of the first color separation prism is vertically arranged, the third surface of the first color separation prism and the second color separation prism are arranged with an air gap, the second surface of the second color separation prism is arranged in contact with the third color separation prism, the first color separation prism, the second color separation prism and the third color separation prism perform light separation processing on the light beam to be color separated, and output light beams of different colors from the first color separation prism, the second color separation prism and the third color separation prism.

2. The color separation prism optical system according to claim 1, characterized in that: The first surface of the first color separation prism is used to input the light beam to be color separated, and the third surface of the first color separation prism is used to reflect the blue light in the light beam to be color separated to the first surface of the first color separation prism, and the blue light is totally reflected on the first surface of the first color separation prism, and the reflected blue light is vertically transmitted out of the prism through the second surface of the first color separation prism.

3. The color separation prism optical system according to claim 2, characterized in that: The reflection condition for the first surface of the first dichroic prism to totally reflect the blue light is: The first total reflection angle is n times the included angle between the first surface and the first prism of the third surface of the first dichroic prism, where n is a natural number greater than 1.

4. The color separation prism optical system according to claim 2, characterized in that: The light beam to be separated is transmitted through the third surface of the first color separation prism to obtain red light in the light beam to be separated, the first surface of the second color separation prism is used to receive the red light, and the second surface of the second color separation prism is used to reflect the red light to the first surface of the second color separation prism, the red light is totally reflected on the first surface of the second color separation prism, and the reflected red light is vertically transmitted out of the prism through the third surface of the second color separation prism.

5. The color separation prism optical system according to claim 4, characterized in that: The reflection condition for the first surface of the second dichroic prism to totally reflect the red light is: The second total reflection angle is determined according to the first prism angle and the second prism angle, wherein the second prism angle is the angle between the first surface and the second surface of the second color separation prism.

6. The color separation prism optical system according to claim 5, characterized in that: The second total reflection angle is determined according to the first prism angle and the second prism angle, including: θ2=2γ-α, wherein θ2 is the second total reflection angle, γ is the second prism angle, and α is the first prism angle.

7. The color separation prism optical system according to claim 4, characterized in that: The green light in the light beam to be separated is transmitted through the first and third surfaces of the first separation prism into the second separation prism, transmitted through the first and second surfaces of the second separation prism into the third prism, and vertically transmitted through the third prism to obtain green light.

8. The color separation prism optical system according to claim 1, characterized in that: The pre-processing module at least includes a UV / IR cut-off filter, a color compensation filter, a neutral grayscale filter and a collimating lens, wherein: The UV / IR cutoff filter is used to filter the ultraviolet light waves and infrared light waves in the incident light; The color compensation filter is used to perform color correction compensation on the incident light; The neutral gray mirror is used to control the intensity of the incident light wave; The collimator is used to shape the incident light and convert the incident light into parallel light or quasi-parallel light.

9. The color separation prism optical system according to claim 1, characterized in that: The color separation prism optical system at least includes a first filter, a second filter and a third filter; Wherein, the first filter is connected to the second surface of the first color separation prism; The second filter is connected to the third surface of the second color separation prism; The third filter is connected to the third color separation prism.

10. A camera device, characterized in that: At least includes the color separation prism optical system as described in any one of claims 1-9, which decomposes the incident light into blue light, red light, and green light, and then transmits them to different image sensors, and obtains images after signal processing.

Images