CN117192675A - Holographic optical element for color suspension transparent display and preparation device and preparation method thereof - Google Patents
Holographic optical element for color suspension transparent display and preparation device and preparation method thereof Download PDFInfo
- Publication number
- CN117192675A CN117192675A CN202311054168.6A CN202311054168A CN117192675A CN 117192675 A CN117192675 A CN 117192675A CN 202311054168 A CN202311054168 A CN 202311054168A CN 117192675 A CN117192675 A CN 117192675A
- Authority
- CN
- China
- Prior art keywords
- optical element
- color
- holographic optical
- holographic
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 290
- 239000000725 suspension Substances 0.000 title claims abstract description 27
- 238000002360 preparation method Methods 0.000 title abstract description 25
- 230000001427 coherent effect Effects 0.000 claims abstract description 23
- 239000000463 material Substances 0.000 claims description 98
- 238000000034 method Methods 0.000 claims description 34
- 230000005540 biological transmission Effects 0.000 claims description 29
- 230000033001 locomotion Effects 0.000 claims description 24
- 239000010410 layer Substances 0.000 claims description 16
- 238000004519 manufacturing process Methods 0.000 claims description 16
- 239000000758 substrate Substances 0.000 claims description 14
- 239000002131 composite material Substances 0.000 claims description 12
- 239000003086 colorant Substances 0.000 claims description 11
- 238000003384 imaging method Methods 0.000 claims description 10
- 230000001678 irradiating effect Effects 0.000 claims description 8
- 239000002356 single layer Substances 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 claims 3
- 230000001105 regulatory effect Effects 0.000 claims 1
- 238000003491 array Methods 0.000 abstract description 4
- 238000011282 treatment Methods 0.000 description 16
- 238000005406 washing Methods 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 12
- 238000011161 development Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 8
- 238000001035 drying Methods 0.000 description 8
- 238000007667 floating Methods 0.000 description 8
- 108010010803 Gelatin Proteins 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 239000000839 emulsion Substances 0.000 description 6
- 229920000159 gelatin Polymers 0.000 description 6
- 235000019322 gelatine Nutrition 0.000 description 6
- 235000011852 gelatine desserts Nutrition 0.000 description 6
- 229910052709 silver Inorganic materials 0.000 description 6
- 239000004332 silver Substances 0.000 description 6
- -1 silver halide Chemical class 0.000 description 6
- 239000008273 gelatin Substances 0.000 description 5
- 230000003190 augmentative effect Effects 0.000 description 4
- 238000004061 bleaching Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000007789 sealing Methods 0.000 description 4
- 238000002791 soaking Methods 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- 238000002834 transmittance Methods 0.000 description 3
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 229920002120 photoresistant polymer Polymers 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
Landscapes
- Holo Graphy (AREA)
Abstract
The invention discloses a holographic optical element for color suspension transparent display, a preparation device and a preparation method thereof. The human eyes can observe the colorful suspension virtual two-dimensional image and the real external environment through the holographic optical element at the same time, so that the superposition of virtual and real information is realized. The preparation device of the holographic optical element comprises a coherent light source, a beam expanding and collimating system, a beam splitter, a movable optical system and the like. The invention adopts the movable optical module to carry out two-dimensional scanning to prepare the holographic optical element for color suspension transparent display. And according to the required focus number and the position, the mobile optical system circularly exposes for a plurality of times according to a planned path. The invention also proposes the preparation of holographic optical elements for color suspended transparent display by point-to-point parallel exposure through microlens arrays.
Description
Technical Field
The invention relates to the technical field of suspension display, in particular to a holographic optical element for realizing color suspension transparent display, and a preparation device and a preparation method thereof.
Background
The floating display technology can utilize a transmission type, reflection type or retro-reflection floating device to image an image into the air, so that immersive off-screen floating display is realized. The floating display is not limited to two-dimensional display tools such as a computer screen, so that a viewer can directly observe objects in the floating display, the reality and immersion sense are stronger, and the experience of the viewer can be greatly enhanced. The display effect breaks through the limitation of the traditional display, does not need to wear additional equipment, reduces the burden of a user, and has very wide application prospect.
Currently, conventional hover devices for hover display are transmissive, reflective, retroreflective, etc., wherein the hover display based on retroreflective hover devices has a relatively large viewing angle as compared to systems using transmissive, reflective hover devices. The retro-reflection type suspended display device consists of two rows of plane mirrors which are perpendicular to each other, images are displayed in the air through multiple reflections of micro-mirrors which are arranged in the device, and a user can directly observe two-dimensional images suspended in the air. However, the retroreflection optical device has low transmittance, so that the effect of not only seeing the suspended image but also seeing the real environment through the suspended display device can not be achieved, and the actual application requirement can not be met. And the demands of viewers are higher and higher, and the demands for realizing color floating display are larger and larger, and the color difference of the traditional floating display based on the retroreflection device is serious although the color display can be realized.
Patent document PCT/JP2013/080288 provides a technique of forming a suspended image on the other side opposite to the photoimaging device with the photoimaging device. By using two light control elements formed of a plurality of strip-shaped planar light reflecting portions provided on a surface of one side of a transparent flat plate, the planar light reflecting portion of the first light control element and the planar light reflecting portion of the second light control element are orthogonal to each other, so that light from an object (or a light source) is incident on the planar light reflecting portion of the first light control element and reflected to the planar light reflecting portion of the second light control element again, and finally a floating display is realized. Patent document CN 207571474U provides an aerial display system, a total reflection mirror disposed at an angle of 45 degrees is disposed above a display, an optical component for refracting and focusing light reflected by the total reflection mirror is disposed at one side of the total reflection mirror, the light passing through the optical component forms a focusing point in front of the optical component and diverges into a real image corresponding to an image on the display in front of an opening, so that the real image is displayed in the air, and a viewer touches the real image with penetrability. Although the two structures are simple, the device has low penetration rate, the perspective similar augmented reality watching effect can not be realized, the chromatic aberration is larger when the color suspension display is realized, the device can not be well combined with a gesture interaction system, and the requirement in practical application is not high.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a preparation device and a preparation method of a holographic optical element capable of realizing color suspension transparent display.
The technical scheme of the invention is as follows:
the holographic optical element for color suspension transparent display comprises a light-transmitting substrate and a color holographic photosensitive film material arranged on the surface of the light-transmitting substrate, and is characterized in that the surface of the color holographic photosensitive film material records two-dimensional array information generated by time sequence exposure or parallel exposure, the two-dimensional array information is formed by synchronously irradiating two coherent point light sources from two sides of the color holographic photosensitive film material, namely the front surface of the color holographic photosensitive film material and the back surface of the color holographic photosensitive film material, at the same position of the color holographic photosensitive film material to generate interference, so as to realize point-to-point superposition exposure, the color holographic photosensitive film material is of a combined structure or a laminated structure, and each coherent point light source is formed by combining three light beams with different colors or formed by time sharing of the light beams with different colors.
Further, the color holographic photosensitive film material is single-layer three-color composite, double-layer composite or three-layer single-color composite.
Further, after the incident light of the display image source is incident from the light-transmitting substrate of the holographic optical element, the incident light is diffracted and modulated by the holographic optical element, and then diffracted by the color holographic photosensitive film material of the holographic optical element, so that a color two-dimensional virtual image suspended in front of the holographic optical element is formed and enters human eyes; ambient light enters human eyes after being transmitted by the holographic optical element, so that virtual and real image superposition is realized.
Further, the holographic optical element is placed at an inclination angle θ, the display image source is placed horizontally below the holographic optical element, and the relative positions of the display image source and the imaging plane with respect to the holographic optical element are determined by the positions of the two-dimensional point array on the holographic optical element.
Further, the inclination angle of the holographic optical element and the horizontal direction is in the range of 10-80 degrees.
On the other hand, the invention also provides a method for manufacturing the holographic optical element for color suspension transparent display, which is characterized in that,
the method comprises the following steps:
providing a light-transmitting substrate, and attaching a color holographic photosensitive film material on one surface of the light-transmitting substrate;
the coherent light is divided into two beams, namely a reference beam and a signal beam, and the coherent point light source is formed by combining three different-color light beams or is formed by time-sharing the three different-color light beams;
Utilizing one sub-lens in the movable optical module or the lens array to enable the reference beam and the signal beam to form two beams of point light sources, and respectively irradiating the opposite positions of the front and back surfaces of the color holographic photosensitive film material synchronously from the front and back surfaces of the holographic photosensitive film material to form point-to-point superposition exposure;
and moving the two beams of point light sources to perform time sequence exposure or parallel exposure to form exposure points in a two-dimensional array. Further, setting the exposure time T of the ij point of the holographic photosensitive film material ij The following conditions are satisfied:
T ij ＝B/I
wherein B is the exposure of the unit area of the color holographic photosensitive film material, and is determined by the material characteristics; i is the exposure intensity of the holographic photosensitive film material unit, and is determined according to actual requirements.
Meanwhile, the invention also provides a preparation device of the holographic optical element for color suspension transparent display, which is characterized in that: the system comprises a first monochromatic laser light source, a second monochromatic laser light source, a third monochromatic laser light source, a beam expanding and collimating system, a first reflecting mirror, a first dichroic mirror, a second dichroic mirror, a beam splitter, a second reflecting mirror, a first moving optical system, a third reflecting mirror, a second moving optical system, a color holographic optical element, a first moving platform driving system, a second moving platform driving system, a master controller, a first electronic shutter, a second electronic shutter, a third electronic shutter, a first attenuator, a second attenuator and a third attenuator;
The method comprises the steps that along the transmission direction of coherent light output by a first monochromatic laser light source, a second monochromatic laser light source and a third monochromatic laser light source, a first attenuator, a second attenuator, a third attenuator, a first reflecting mirror, a first dichroic mirror, a second dichroic mirror, a beam expanding and collimating system and a beam splitter are placed, the first attenuator, the second attenuator and the third attenuator are used for controlling the power of the coherent light output by the first monochromatic laser light source, the second monochromatic laser light source and the third monochromatic laser light source, the beam expanding and collimating system of the beam expanding and collimating system is used for collimating and expanding the coherent light output by the first monochromatic laser light source, the second monochromatic laser light source and the third monochromatic laser light source to form parallel light of a wide beam, and the parallel light is divided into two beams through the beam splitter, namely reflected light serving as reference light and transmitted light serving as signal light;
the second reflecting mirror and the first moving optical system are sequentially arranged along the transmission direction of the reference light, the first moving optical system is connected with the first moving platform driving system, and the first moving optical system is used for irradiating the reference light on a holographic optical element to be prepared and converging the reference light behind the holographic optical element;
The third reflecting mirror and the second movable optical system are sequentially arranged along the transmission direction of the signal light, the second movable optical system is connected with a second movable platform driving system, and the second movable optical system is used for irradiating the signal light on a holographic optical element to be prepared and converging the signal light in front of the holographic optical element;
the master controller is respectively connected with the first mobile platform driving system, the second mobile platform driving system, the first electronic shutter, the second electronic shutter and the third electronic shutter and used for controlling the working states of the first mobile platform driving system, the second mobile platform driving system, the first electronic shutter, the second electronic shutter and the third electronic shutter; and the positions of the first mobile optical system and the second mobile optical system are adjusted by controlling the first mobile platform driving system and the second mobile platform driving system, so that the reference light and the signal light synchronously irradiate the same position of the holographic optical element to be prepared to generate interference, and point-to-point exposure is realized. If the color holographic optical element adopts a combined structure, the master controller controls the first electronic shutter, the second electronic shutter and the third electronic shutter to be opened and closed simultaneously according to the motion states of the first moving optical system and the second moving optical system, so that the exposure of the two-dimensional array point positions on the holographic optical element to be prepared is completed; if the color holographic optical element adopts a laminated structure, the master controller opens the electronic shutters corresponding to the lasers of the corresponding color channels according to the current exposure color, and controls the electronic shutters to open and close according to the motion states of the first moving optical system and the second moving optical system, so that the exposure of the two-dimensional array point positions on the holographic optical element to be prepared is completed.
Further, the first mobile optical system comprises a first space mobile platform, a third reflector and a third lens, wherein the third reflector and the third lens are arranged on the first space mobile platform along the transmission direction of reference light, the reference light is reflected by the third reflector and then transmitted by the third lens to form convergent spherical waves, the convergent spherical waves irradiate on the holographic optical element to be prepared and are converged behind the holographic optical element to be prepared; the second movable optical system comprises a second space movable platform, a fourth reflecting mirror and a fourth lens, wherein the fourth reflecting mirror and the fourth lens are arranged on the second space movable platform along the transmission direction of signal light, the signal light is transmitted through the fourth lens after being reflected by the fourth reflecting mirror, divergent light formed after a focal plane irradiates on a holographic optical element to be prepared, and spherical waves formed after a third lens in the first movable optical system interfere on the holographic optical element to be prepared.
Further, the first moving platform driving system is composed of a first motor and a motor driver, and the second moving platform driving system is composed of a second motor and a motor driver.
The invention also provides a device for preparing the suspended transparent holographic optical element, which is characterized in that: the system comprises a first monochromatic laser light source, a second monochromatic laser light source, a third monochromatic laser light source, a beam expansion and collimation system, a first reflecting mirror, a first dichroic mirror, a second dichroic mirror, a beam splitter, a second reflecting mirror, a holographic optical element, a third reflecting mirror, a first lens array, a second lens array, a relay optical system, a first electronic shutter, a second electronic shutter, a third electronic shutter, a first attenuator, a second attenuator and a third attenuator;
The method comprises the steps that along the transmission direction of coherent light output by a first monochromatic laser light source, a second monochromatic laser light source and a third monochromatic laser light source, a first attenuator, a second attenuator, a third attenuator, a first reflecting mirror, a first dichroic mirror, a second dichroic mirror, a beam expanding and collimating system and a beam splitter are placed, the first attenuator, the second attenuator and the third attenuator are used for controlling the power of the coherent light output by the first monochromatic laser light source, the second monochromatic laser light source and the third monochromatic laser light source, the beam expanding and collimating system is used for collimating and expanding the coherent light output by the first monochromatic laser light source, the second monochromatic laser light source and the third monochromatic laser light source to form parallel light with a wide beam, and the parallel light is divided into two beams by the beam splitter, namely reflected light serving as reference light and transmitted light serving as signal light;
the second reflecting mirror, the third reflecting mirror, the first lens array and the relay optical system are sequentially arranged along the reference light transmission direction, and the relay optical system is used for imaging a focus array formed by the first lens array onto a holographic optical element to be prepared;
the second lens array and the holographic optical element to be prepared are sequentially arranged along the signal light transmission direction, the second lens array is formed by arranging a plurality of small lenses and is used for dividing a laser wave front into a plurality of parts in space, each part is focused by the corresponding small lens to form a two-dimensional array consisting of a series of focuses, the two-dimensional array is converged on the holographic optical element, and the two-dimensional array interferes with the focus array formed after the relay optical system on the holographic optical element to be prepared;
The master controller is respectively connected with the first mobile platform driving system, the second mobile platform driving system, the first electronic shutter, the second electronic shutter and the third electronic shutter, and if the color holographic optical element adopts a combined structure, the master controller controls the first electronic shutter, the second electronic shutter and the third electronic shutter to be simultaneously opened and closed according to the exposure time required by preparing the holographic optical element, so that parallel exposure of two-dimensional array points on the holographic optical element to be prepared is completed; if the color holographic optical element adopts a laminated structure, the master controller opens the electronic shutter corresponding to the laser of the corresponding color channel according to the current exposure color until the three colors are exposed, thereby ending the exposure of the two-dimensional array point positions on the holographic optical element to be prepared.
Further, the relay optical system is composed of a first relay lens and a second relay lens.
Further, the back focal plane position of the first lens array is in a conjugate relationship with the desired focal array plane position.
Compared with the prior art, the invention has the beneficial effects that:
1. the transparent color holographic optical element is used as an imaging device, so that a color image can be suspended in the air between the device and human eyes, and the human eyes can observe the suspended image and the real environment through the holographic optical element, so that the superposition of virtual and real information is realized, and the effect of augmented reality can be achieved. The color holographic optical element has certain wavelength selectivity to light rays with three wavelengths of red, blue and green, and can obtain good optical perspective observation effect.
2. The holographic optical element prepared by the invention can suspend the displayed color two-dimensional image in the air, and can well combine a suspended display system with a gesture interaction system. The image suspension area is overlapped with the gesture control area, so that a user can directly control the suspended image by using gestures as if the user is actually controlling an object, the experience of the user can be greatly improved, and the actual application requirements of the user are better met. The color two-dimensional image is suspended in the air, so that the color two-dimensional image is more realistic and has more application scenes, and the actual requirements of viewers are met.
3. The two-dimensional array is formed on the color holographic optical element through single-color exposure and three-layer superposition or three-color simultaneous exposure, and the divergence angle of the laser light source irradiated on the holographic optical element to be prepared is controlled, so that the divergence angle of the two-dimensional array is controlled, a large field angle can be obtained, and a larger viewing range can be realized.
4. The preparation device has strong ductility, holographic optical elements with various sizes and precision meeting specific use requirements can be flexibly prepared by controlling the displacement distance of the movable platform and the interval between exposure points, and the preparation method is simple.
5. The display adopts laser projection or laser backlight source, and the design wavelength phase-match with holographic optical element can reach the colour gamut wider, and the colour saturation is higher, can realize better viewing effect, can avoid because the stack of RGB device leads to the great problem of volume when using.
6. A movable optical module is adopted to carry out two-dimensional scanning to prepare the holographic optical element for color suspension transparent display. And according to the required focus number and the position, the mobile optical system circularly exposes for a plurality of times according to a planned path. The invention also proposes the preparation of holographic optical elements for color suspended transparent display by point-to-point parallel exposure through microlens arrays.
Drawings
FIG. 1 is a working light path diagram of a holographic optical element for color suspended transparent display provided in embodiment 1 of the present invention;
FIG. 2 is a diagram showing a structure of a holographic optical element for realizing color suspended transparent display according to embodiment 1 of the present invention;
FIG. 3 is a schematic diagram of the operation of a holographic optical element for color suspended transparent display according to example 1 of the present invention;
fig. 4 is a schematic structural diagram of a holographic optical element manufacturing apparatus for realizing color suspended transparent display based on a movable optical module provided in embodiment 2 of the present invention;
Fig. 5 is a flowchart of a method for manufacturing a combined holographic optical element for realizing color suspended transparent display based on a movable optical module in embodiment 2 of the present invention.
Fig. 6 is a flowchart of a method for manufacturing a laminated holographic optical element for realizing a color suspended transparent display based on a movable optical module according to embodiment 2 of the present invention.
Fig. 7 is a working timing chart of a method for manufacturing a holographic optical element for realizing color suspended transparent display based on a movable optical module in embodiment 2 of the present invention.
FIG. 8 is a schematic structural diagram of a device for preparing a holographic optical element for realizing color suspended transparent display based on a lens array according to embodiment 3 of the present invention;
fig. 9 is a flowchart of a method for manufacturing a combined holographic optical element for realizing color suspended transparent display based on a microlens array according to embodiment 3 of the present invention.
Fig. 10 is a flowchart of a method for manufacturing a laminated hologram optical element for realizing a color suspended transparent display based on a microlens array according to embodiment 3 of the present invention.
In the figure: 100 is a first monochromatic laser light source, 110 is a second monochromatic laser light source, 120 is a third monochromatic laser light source, 130 is a beam expanding and collimating system, 140 is a first mirror, 150 is a first dichroic mirror, 160 is a second dichroic mirror, 170 is a beam splitter, 180 is a second mirror, 190 is a first moving optical system, 210 is a third mirror, 220 is a second moving optical system, 200 is a color hologram optical element, 230 is a first moving stage drive system, 240 is a second moving stage drive system, 250 is a master controller, 260 is a first electronic shutter, 270 is a second electronic shutter, 280 is a third electronic shutter, 290 is a first attenuator, 300 is a second attenuator, 310 is a third attenuator, 330 is a third mirror, 340 is a first lens array, 360 is a second lens array, and 350 is a relay optical system.
It should be understood that the above-described figures are merely schematic and are not drawn to scale.
Example 1
The holographic optical element for color suspension transparent display is a flat diffraction optical element, consists of a color holographic material and a light-transmitting substrate, can be manufactured through simulated holographic exposure or digital holographic printing, has certain wavelength selectivity, and is generally prepared by using a photosensitive film material. The color holographic material is formed by exposing one layer of holographic photosensitive film material by coherent light with three exposure wavelengths sequentially, or is formed by exposing three layers of holographic photosensitive film materials respectively with red, green and blue colors and then combining the three layers of holographic photosensitive film materials.
Fig. 1 is a working light path diagram of a holographic optical element for color suspended transparent display provided in embodiment 1 of the present invention. The color hologram optical element 200 (hereinafter referred to as hologram optical element) includes a color hologram material 201 and a light-transmitting substrate 202. The color holographic material 201 is a color composite color holographic recording material, and common holographic recording materials include silver halide emulsion, dichromated gelatin, photoresist, photopolymer, photoconductive thermoplastic and the like, and the transmittance thereof can reach 90%. The three types of color hologram recording materials 200 can be single-layer three-color composite, double-layer composite (one layer is one color, and the other layer is two colors), or three-layer single-color composite (each layer corresponds to one color), and the exposure processes corresponding to different composite types are different, as shown in fig. 2. The light-transmitting substrate 202 may be a glass material or a resin material.
The hologram optical element 200 is disposed at a certain inclination angle θ with respect to the horizontal direction, and the range of θ is generally 10 ° to 80 °, and the specific angle is determined by parameters of the hologram optical element, preferably 45 °. Incident light emitted by a display image source irradiates the holographic optical element 200 from the lower part of the holographic optical element 200, the incident light is subjected to diffraction modulation of the holographic optical element, a color two-dimensional image suspended in front of the holographic optical element is formed on a corresponding imaging surface, and the color two-dimensional image can be observed by human eyes. At the same time, the ambient light is also transmitted through the holographic optical element from the right side without deflection and is incident to human eyes. The human eyes can observe the colorful suspension virtual image and the external real environment at the same time through the holographic optical element, so that the superposition of virtual and real information can be realized, and the effect of augmented reality is achieved.
The working principle of the prepared holographic optical element provided in embodiment 1 of the present invention for realizing suspended transparent display is shown in fig. 3, and includes a display image source 300 and a holographic optical element 200. The display image source 300 is used to provide a color image source, such as red, green and blue light, to achieve a color display. The display image source 300 may be a two-dimensional display screen such as an LCD (liquid crystal display), an LED screen (light emitting diode), an OLED screen (organic light emitting diode), a VFD screen (vacuum fluorescent display), a PDP screen (plasma display), a projection display screen, or the like. The types of screens used are different, the viewing effects produced are also different, and the type of screen installed should be selected according to the requirements in actual use. The center wavelength of the display image source 300 for displaying red, green and blue is matched with the three-color laser wavelength of the hologram optical element 200, and the difference of the center wavelength is generally not more than 20nm.
The display image source 300 is generally horizontally disposed below the holographic optical element 200 at a suitable distance to match the design position of the holographic optical element 170. After the size of the display image source 300 and the size and position of the holographic optical element 200 are determined, an image is loaded on the display image source 300, and the incident light emitted by the display image source 300 is subjected to diffraction modulation by the holographic optical element 200, so that a color two-dimensional image suspended in front of the holographic optical element 200 is formed on the corresponding imaging surface 301. The imaging plane 301 is located between the human eye and the holographic optical element, and the human eye can observe the color suspended virtual image located on the imaging plane, and at the same time, the ambient light is also transmitted through the holographic optical element from the right side without deflection and is incident to the human eye together. As shown in fig. 2, if a color image is loaded on the display image source 300, after being subjected to diffraction modulation by the holographic optical element 170, a color image suspended in air in front of the holographic optical element is formed on the imaging surface 301, and can be observed by human eyes, and meanwhile, external light is incident to human eyes through the holographic optical element. The human eyes can observe the suspended virtual two-dimensional image and the real external environment at the same time through the holographic optical element, and the superposition of virtual and real information is realized, so that the effect of augmented reality is achieved.
Example 2
The present invention provides an embodiment of a preparation apparatus for a holographic optical element for implementing a color suspended transparent display, as shown in fig. 4, the preparation apparatus for a holographic optical element for implementing a color suspended transparent display includes a first monochromatic laser light source 100, a second monochromatic laser light source 110, a third monochromatic laser light source 120, a beam-expanding collimating system 130, a first reflecting mirror 140, a first dichroic mirror 150, a second dichroic mirror 160, a beam splitter 170, a second reflecting mirror 180, a first moving optical system 190, a fourth reflecting mirror 210, a second moving optical system 220, a holographic optical element 200, a first moving stage driving system 230, a second moving stage driving system 240, a master controller 250, a first electronic shutter 260, a second electronic shutter 270, a third electronic shutter 280, an electronic shutter controller 320, a first attenuator 290, a second attenuator 300, and a third attenuator 310.
The first monochromatic laser source 100, the second monochromatic laser source 110 and the third monochromatic laser source 120 may be respectively a red laser source, a green laser source or a blue laser source, and the arrangement sequence of the three-color lasers may be changed according to specific situations. The wavelength of the laser is matched with the actual preparation requirement so as to realize the preparation of the holographic optical element.
The first reflecting mirror 140 is a plane reflecting mirror for changing the direction of the laser light emitted from the first monochromatic laser light source 100. The first dichroic mirror 150 and the second dichroic mirror 160 have significantly different reflection or transmission characteristics at two different wavelengths, i.e., the light beam can be separated into transmitted light and reflected light according to wavelength. The first dichroic mirror 150 is located between the first reflecting mirror 140 and the second dichroic mirror 160, and is configured to transmit the laser beam output by the first monochromatic laser source 100, reflect the laser beam output by the second monochromatic laser source 110, and combine the laser beams output by the first monochromatic laser source 100 and the second monochromatic laser source 110. The second dichroic mirror 160 is located behind the first dichroic mirror 150, and is configured to transmit the laser beams of the first monochromatic laser source 100 and the second monochromatic laser source 110 combined by the first dichroic mirror 150, reflect the laser beam output by the third monochromatic laser source 120, and implement the combination of the laser beams output by the first monochromatic laser source 100, the second monochromatic laser source 110 and the third monochromatic laser source 120. If the first monochromatic laser light source 100 is red, the second monochromatic laser light source 110 is green, and the third monochromatic laser light source 120 is blue, the first dichroic mirror 150 transmits red light and reflects green light, and the second dichroic mirror transmits red light and green light and reflects blue light. The wavelengths of the first, second, and third monochromatic laser light sources 100, 110, 120 determine the start and stop wavelengths of the first and second dichroic mirrors 150, 160.
The beam expansion and collimation system 130 is located behind the second dichroic mirror 160, and is configured to perform collimation, beam expansion and filtering on the laser beams combined by the first monochromatic laser source 100, the second monochromatic laser source 110, and the third monochromatic laser source 120 to obtain high-quality broad-beam parallel light. The expanded beam collimation system 130 generally consists of a first lens 131, a pinhole filter 132, and a second lens 133. Generally, the first monochromatic laser source 100, the second monochromatic laser source 110 and the third monochromatic laser source 120 generate laser, which is converged by the first lens 131 to the pinhole filter 132 to filter out stray light and generate spherical waves close to ideal, and then collimated by the second lens 133 to generate parallel light with wide beams. The first lens 131 may be a single lens, a double cemented lens, or a combination of a plurality of lenses. The pinhole filter 132 is generally used to filter stray light in the light beam emitted from the laser source to improve the beam quality. The second lens 133 may be a single lens, a double cemented lens or a lens group composed of a plurality of lenses, and the beam size of the collimated light beam after beam expansion is determined by the lens aperture and focal length of the second lens 133.
The beam splitter 170 is a block beam splitter prism or a plate beam splitter, and splits an incident beam into two beams. The beam splitter 170 divides the parallel light collimated by the beam expansion and collimation system 130 into two beams, the beam reflected by the beam splitter 170 is the reference light, and the beam transmitted by the beam splitter 170 is the signal light.
The second mirror 180 is a plane mirror for changing the direction of the parallel light so that the reference light is irradiated onto the third mirror 192. The first moving optical system 190 is composed of a first spatially-moving stage 191, a third mirror 192, and a third lens 193. The first movable optical system 190 is connected to a first movable stage driving system 230, and the two-dimensional scanning movement of the first movable stage driving system 230 is controlled. The third mirror 192 and the third lens 193 are disposed on the first spatially-moving stage 191, and the third lens 193 is disposed behind the third mirror 192. The reference light is reflected by the third mirror 192 and then forms a converging spherical wave by the third lens 193, irradiates the hologram optical element 200, converges behind the hologram optical element 200, and can realize a wide viewing range by controlling the divergence angle of the reference light. In the actual manufacturing process, motion control is required according to the designed focal position. The first spatially-moving stage 191 can be moved along the x-axis or the z-axis, respectively, to meet the requirements of a focus two-dimensional scanning exposure.
The fourth mirror 210 is a plane mirror for changing the direction of the parallel light. The second moving optical system 220 is composed of a second spatial moving stage 221, a fifth mirror 222, and a fourth lens 223. The second moving optical system 220 is connected to the second moving stage driving system 240, and the second moving stage driving system 240 controls the two-dimensional scanning motion thereof. The fifth mirror 222 and the fourth lens 223 are disposed on the second space-moving stage 221, and the fourth lens 223 is disposed behind the fifth mirror 222. The reference light is reflected by the fifth reflecting mirror 222 and then passes through the fourth lens 223, and the divergent light formed after the focal plane is irradiated onto the hologram optical element 200, and interferes with the spherical wave formed after the third lens 193 in the first moving optical system 190 on the hologram optical element 200. In the actual manufacturing process, motion control is required according to the designed focal position. The second spatial translation stage 221 can be translated along either the y-axis or the z-axis to meet the requirements of a two-dimensional scanning exposure of the focal point. The movement ranges of the first and second spatial movement stages 191 and 221 determine the size of the prepared hologram optical element 200, and the specific size is determined according to actual requirements.
The position of the first spatial mobile platform 191 is determined by the first mobile platform driving system 230. The first moving platform driving system 230 is composed of a first motor 231 and a first motor driver 232, and is connected with the overall controller 250, and the connection mode of the first moving platform driving system and the overall controller can be USB, serial port, general I/O, etc. for controlling the spatial position of the first moving optical system 190, and the transmission mode between the first motor 231 and the first space moving platform 191 can be belt transmission, gear transmission or combination transmission of multiple transmission modes. The combination of the third mirror 192 and the third lens 193 may be replaced with a curved mirror to achieve a similar function. The third lens 193 may be a single lens, a double cemented lens, or a lens group composed of a plurality of lenses. The third motor 181 is typically a stepper motor or a servo motor. The first motor drive 182 should be matched to the selected motor.
The position of the second spatial stage 221 is determined by the second stage drive system 240. The mobile platform driving system 190 is composed of a second motor 191 and a second motor driver 192, and is connected with the overall controller 250, and is used for controlling the spatial position of the movable optical module 160, and the transmission mode between the second motor 191 and the second spatial mobile platform 221 can be belt transmission, gear transmission or combination transmission of multiple transmission modes. The fourth lens 223 may be a single lens, a double cemented lens, or a lens group composed of a plurality of lenses. The second motor 191 is typically a stepper motor or a servo motor. The second motor drive 192 should be matched to the selected motor. In the actual manufacturing process, cooperative motion control of the first spatially-moving stage 191 and the second spatially-moving stage 221 is required according to the designed focal position.
The hologram optical element 200 is a color composite hologram recording material, and is generally prepared by using a photosensitive film material. The color holographic material is formed by exposing one layer of holographic photosensitive film material by coherent light with three exposure wavelengths sequentially, or is formed by exposing three layers of holographic photosensitive film materials respectively with red, green and blue colors and then combining the three layers of holographic photosensitive film materials. Typical holographic recording materials are silver halide emulsions, dichromated gelatins, photoresists, photopolymers, photoconductive thermoplastics, and the like. The photopolymer holographic recording material has the advantages of high sensitivity and diffraction efficiency, convenient processing, real-time dry development and the like, and the transmittance can reach 90 percent. The transparent substrate can be made of glass or acrylic plate, and the thickness of the prepared holographic optical element can reach 1-2mm, and the weight of the holographic optical element is lighter. The hologram optical element 200 is generally disposed obliquely, so that the signal light and the reference light can be effectively interfered. The photosensitive surface of the holographic optical element 200 is generally parallel to the x-axis and 45 deg. to the y-axis.
The first electronic shutter 260, the second electronic shutter 270, and the third electronic shutter 280 are electromagnetic shutters, and are all connected to the electronic shutter controller 320. The electronic shutter controller 320 may be a single chip microcomputer, an FPGA, a PLC, a micro control system, etc., and is connected to the overall controller 250 to control the working states of the first electronic shutter 260, the second electronic shutter 270, and the third electronic shutter 280. The master controller 250 may be a single chip microcomputer, an FPGA, a PLC, a micro control system, etc. and is used for controlling the operation of the motor and the working state of the electronic shutter. The overall controller 250 is connected to the first motor driver 182 and the second motor driver 192 for controlling the movement of the first space movement platform 191 and the second space movement platform 221 along the directions of the respective coordinate axes, and the overall controller 250 is connected to the electronic shutter controller 320 for controlling the opening and closing of the first electronic shutter 260, the second electronic shutter 270 and the third electronic shutter 280. The overall controller 250 is to control the operation states of the first electronic shutter 260, the second electronic shutter 270, and the third electronic shutter 280 in combination with the operation states of the first spatial mobile platform 191 and the second spatial mobile platform 221. When the first and second spatial movement platforms 191 and 221 move, the overall controller 250 controls the first, second and third electronic shutters 260, 270 and 280 to block the light path; when the first and second space moving stages 191 and 221 stop, the overall controller 250 may simultaneously control the first and second electronic shutters 260, 270 and 280 to open the light paths to perform RGB three-color simultaneous exposure on the target holographic optical element 200, or may respectively control the first and second electronic shutters 260, 270 and 280 to open the light paths to perform RGB three-color time-sharing exposure on the target holographic optical element 200.
The first attenuator 290, the second attenuator 300, and the third attenuator 310 are devices for attenuating the light intensity for each color light path of RGB, and are used for adjusting and controlling the exposure beam intensity of the exposure target hologram optical element 200.
The embodiment 1 of the invention provides a preparation method of a combined holographic optical element for realizing color suspension transparent display through time sequence exposure, and the specific flow is shown in fig. 5, and the method comprises the following steps:
the first step: the exposure position and the inclination angle of the holographic optical element are determined first, and the specific positions of the two optical moving systems and other devices are determined according to the position of the holographic optical element. The running speed of the space moving platform can be set according to the rated rotating speed of the motor and matched with a speed reducer, the position of each focus in the focus array required to pass through in the moving process of the two space moving platforms is determined, and the initial positions of the two space moving platforms, namely the exposure position of the first point, are respectively adjusted.
And a second step of: the world coordinate system is initialized, and a running path is planned according to the position of the focal array, and can be row-by-row exposure or column-by-column exposure or other reasonable running paths. Determining the specific position F of each focus according to the system parameters such as the exposure light intensity, the holographic material, the focus number (M multiplied by N) of the focus array, the single-point exposure times and the like ij Exposure time T required for the ijth point on the holographic photosensitive film ij (i, j is the focal order of the current exposure). The distance of movement or the spacing between exposure spots is determined by the manufacturing requirements and the expected size of the holographic optical element. Exposure time T ij Can be made of T ij The result is =b/I. Wherein the exposure per unit area of the B-hologram photosensitive film (unit is generally mJ/cm 2 ) I is the exposure intensity (typically in mW/cm 2 )，T ij Exposure time (typically in s). Wherein B is determined by the characteristics of the selected material and the exposure intensity is determined according to the specific exposure requirements. The exposure light intensity is determined according to the proportion of the three-color laser during exposure.
And a third step of: when the space moving platform moves to the focal position of the ij (i is more than or equal to 1 and less than or equal to M, j is more than or equal to 1 and less than or equal to N) needing exposure according to the planned path, the space moving platform brakes and keeps static for t time, and the master controller receives the braking feedback of the space moving platform and judges whether the preparation device is stable or not within t time. Note that the position of the light rays impinging on the color holographic material after each movement through the two spatial movement stages should remain the same.
Fourth step: the method is used for the color holographic material and adopts a combined structure, and after judging that the space moving platform is stable and waiting for the time T to finish, three electronic shutters are simultaneously opened to switch on the light path and the electronic shutters are kept open for a period of time T according to the calculated exposure time ij The electronic shutter is closed after the exposure is completed.
Fifth step: and circularly executing the third step and the fourth step to circularly expose the next focus position one or more times, and ensuring that the diffraction efficiency of each focus position is relatively uniform until M multiplied by N focuses are exposed.
Sixth step: and stopping the movement after the exposure, and carrying out bleaching post-treatment on the color holographic material subjected to the exposure to obtain the holographic optical element for color suspension transparent display.
In the third step, the movement time of the space moving platform can be determined by the focus position and the running speed of the device, and can also be adaptively adjusted by a feedback control system. Useful feedback control sensors are contact switches, accelerometers or hall sensors, etc.
The post-treatment of the holographic optical element for realizing the color suspended transparent display in the sixth step should employ different treatment methods for the material correspondence of the holographic optical element. Such as: the holographic optical element of silver halide emulsion material requires post-treatments of development, water washing, stop-development, fixing, water washing and drying. Holographic optical elements of dichromated gelatin materials require prior use (NH 4 ) 2 Cr 2 O 7 Washing with solution, soaking in hardening liquid of the same kind, washing with water, dehydrating with isopropanol, and finally drying, sealing and solidifying. The holographic optical element of the photopolymer material can be processed by adopting a dry method, and compared with other materials, the color holographic image recorded by the photopolymer has higher geometric fidelity, long storage time and difficult distortion.
Embodiment 1 of the present invention provides a method for preparing a laminated holographic optical element for realizing color suspended transparent display by time-series exposure, the specific flow is shown in fig. 6, and the method comprises:
the first step: the exposure position and the inclination angle of the holographic material are determined, and the specific positions of the two optical moving systems and other devices are determined according to the position of the holographic material. And then, setting the running speed of the space moving platform according to the rated rotating speed of the motor and a speed reducer, determining the position of each focus in the focus array required to pass through in the moving process of the two space moving platforms, and respectively adjusting the initial positions of the two space moving platforms, namely the exposure position of the first point.
And a second step of: the world coordinate system is initialized, and a running path is planned according to the position of the focal array, and can be row-by-row exposure or column-by-column exposure or other reasonable running paths. Determining the specific position F of each focus according to the system parameters such as the exposure light intensity, the holographic material, the focus number (M multiplied by N) of the focus array, the single-point exposure times and the like ij Exposure time T required for each focus ij (i, j is the focal order of the current exposure). The distance of movement or the spacing between exposure spots is determined by the manufacturing requirements and the expected size of the holographic optical element.
And a third step of: when the space moving platform moves to the focal position of the ij (i is more than or equal to 1 and less than or equal to M, j is more than or equal to 1 and less than or equal to N) needing exposure according to the planned path, the space moving platform brakes and keeps static for t time, and the master controller receives the braking feedback of the space moving platform and judges whether the preparation device is stable or not within t time. Note that the position of the light rays impinging on the color holographic material after each movement through the two spatial movement stages should remain the same.
Fourth step: the method is characterized in that the color holographic material adopts a laminated structure, after judging that the space moving platform is stable and waiting for the time T to finish, opening the electronic shutter corresponding to the laser of the corresponding color channel of the exposure, and keeping the electronic shutter open for a period of time T according to the calculated exposure time ij The electronic shutter is closed after the exposure is completed.
Fifth step: the third and fourth steps are cyclically performed to expose different focus points of the holographic optical element.
Sixth step: and stopping the exposure, ending the scanning, and carrying out bleaching post-treatment on the prepared holographic material. Then cutting new material in dark environment and covering the holographic exposure material on the material just exposed.
Seventh step: repeating the third step to the sixth step until the exposure coverage of all three colors is completed, and obtaining the holographic optical element for realizing color suspension transparent display.
In the third step, the movement time of the space moving platform can be calculated by the focus position and the running speed of the device, and can also be self-adjusted by feedback control. Available feedback modes are contact switches, accelerometers or hall sensors, etc.
The post-treatment of the holographic optical element in the sixth and seventh steps should be performed using different treatment methods for the material of the holographic optical element. Such as: the holographic optical element of silver halide emulsion material requires post-treatments of development, water washing, stop-development, fixing, water washing and drying. Holographic optical elements of dichromated gelatin materials require prior use (NH 4 ) 2 Cr 2 O 7 Washing with solution, soaking in hardening liquid of the same kind, washing with water, dehydrating with isopropanol, and finally drying, sealing and solidifying. The holographic optical element of the photopolymer material can be processed by adopting a dry method, and compared with other materials, the color holographic image recorded by the photopolymer has higher geometric fidelity, long storage time and difficult distortion.
Embodiment 1 of the present invention provides an operation timing chart of a method for manufacturing a hologram optical element for realizing a color suspended transparent display, as shown in fig. 7. The timing of one of the cycles is: the first and second spatial mobile platforms 191 and 221 respectively travel along the planned path for a certain time T 0 When the movable platform reaches the exposure position and is braked, the master controller receives a brake feedback signal to judge whether the movable platform is stable after being braked within the time T, and the movable platform is braked within the time T 0 The electronic shutter is in a closed state for a + t time. After the master controller judges that the space mobile platform is braked and stabilized, one of the electronic shutters is opened and kept open T i And (3) time, wherein the space mobile platform is kept stationary. According to the upper partThe periodic process completes the two-dimensional exposure of the movable optical module and performs exposure of a plurality of positions at least once, namely completes the preparation of the holographic optical element for color suspension transparent display. The scan path may be a line-by-line scan or a column-by-column scan or a designed specific route, etc.
Example 3
The present invention provides one embodiment of a fabrication apparatus for a holographic optical element for implementing a color suspended transparent display, as shown in fig. 8. The preparation device of the holographic optical element for realizing color suspension transparent display comprises a first monochromatic laser light source 100, a second monochromatic laser light source 110, a third monochromatic laser light source 120, a beam-expanding and collimating system 130, a first reflecting mirror 140, a first dichroic mirror 150, a second dichroic mirror 160, a beam splitter 170, a second reflecting mirror 180, a holographic optical element 200, a sixth reflecting mirror 330, a first lens array 340, a second lens array 360, a relay optical system 350, a general controller 250, a first electronic shutter 260, a second electronic shutter 270, a third electronic shutter 280, an electronic shutter controller 320, a first attenuator 290, a second attenuator 300 and a third attenuator 310.
The first monochromatic laser source 100, the second monochromatic laser source 110 and the third monochromatic laser source 120 may be respectively a red laser source, a green laser source or a blue laser source, and the arrangement sequence of the three-color lasers may be changed according to specific situations. The monochromatic laser may be a semiconductor laser, a gas laser or a solid state laser.
The first reflecting mirror 140 is a plane reflecting mirror for changing the direction of the laser light emitted from the first monochromatic laser light source 100. The first dichroic mirror 150 and the second dichroic mirror 160 have significantly different reflection or transmission characteristics at two different wavelengths, i.e., the light beam can be separated into transmitted light and reflected light according to wavelength. The wavelengths of the first, second, and third monochromatic laser light sources 100, 110, and 120 determine the start and stop wavelengths of the first and second dichroic mirrors 150, 160. The laser light beam combination output by the first, second, and third monochromatic laser light sources 100, 110, and 120 is achieved by the first and second dichroic mirrors 150 and 160.
The beam expansion and collimation system 130 is configured to perform collimation, beam expansion and filtering on the combined light beams output by the first monochromatic laser source 100, the second monochromatic laser source 110 and the third monochromatic laser source 120 to obtain high-quality wide-beam parallel light. The expanded beam collimation system 130 generally consists of a first lens 131, a pinhole filter 132, and a second lens 133.
The beam splitter 170 is a block beam splitter prism or a flat beam splitter, and divides the parallel light collimated by the beam expanding and collimating system 130 into two beams, the beam reflected by the beam splitter 170 is a reference beam, and the beam transmitted by the beam splitter 170 is a signal beam. The signal light transmitted through the beam splitter 170 irradiates the hologram optical element 200 through the second reflecting mirror 180, the sixth reflecting mirror 330, the first lens array 340, and the relay optical system 350; the reference light reflected by the beam splitter 170 passes through the second lens array 360 to form a focal array and irradiates the hologram optical element 200.
The second mirror 180 is a plane mirror for changing the direction of the parallel light so that the signal light transmitted by the beam splitter 170 is irradiated onto the sixth mirror 330. The sixth mirror 330 is a plane mirror for changing the direction of the parallel light and collimated to illuminate the first lens array 340.
The array of the first lens array 340 and the second lens array 360 is composed of a plurality of lenses, and the plurality of lenses are arranged in a certain mode to spatially divide a complete laser wavefront into a plurality of tiny parts, and each part is focused by a corresponding small lens to form a two-dimensional array composed of a series of focuses.
The relay optical system 350 may be a 4f optical system, and is composed of a first relay lens 351 and a second relay lens 352. The back focal plane position of the first lens array 340 is in a conjugate relationship with the desired focal array plane position of the holographic optical element 200. The magnification of the 4f optical system is determined by the focal length ratio of the first relay lens 351 and the second relay lens 352.
The holographic optical element 200 is a planar diffraction optical element, and can be manufactured by analog holographic exposure or digital holographic printing, and has certain wavelength selectivity. Typically by photosensitive film materials. The hologram optical element 200 is generally disposed obliquely, so that the signal light and the reference light can be effectively interfered, and a wide viewing range can be realized by controlling the divergence angle of the signal light and the reference light. Typically the photosensitive surface of the holographic optical element 200 is parallel to the x-axis and 45 ° to the y-axis.
The signal light transmitted through the beam splitter 170 and the reference light reflected through the beam splitter 170 interfere with each other on the hologram optical element 200 through the first lens array 340, the relay optical system 350, and the second lens array 360, respectively, and perform point-to-point superimposed exposure. Preferably, the distance from the focal plane of the second lens array 360 to the holographic optical element 200 is equal to the distance from the desired focal array plane to the holographic optical element 200.
The first electronic shutter 260, the second electronic shutter 270 and the third electronic shutter 280 are electromagnetic shutters, or electronic control mechanical shutters, or mechanical electronic systems with similar functions, and are connected with the electronic shutter controller 320 and the overall controller 250 for controlling the working states of the first electronic shutter 260, the second electronic shutter 270 and the third electronic shutter 280.
The first attenuator 290, the second attenuator 300, and the third attenuator 310 may be laser power attenuators for controlling the power of the laser light in the optical path.
Embodiment 3 of the present invention provides a method for preparing a combined holographic optical element for implementing color suspension transparent display by parallel exposure, and the specific flow is shown in fig. 9, and the method includes:
the first step: the exposure position and the inclination angle of the holographic material are determined, and the specific positions of the two lens arrays and other devices are determined according to the position of the holographic material. The exposure time and the exposure intensity required for preparing the holographic optical element for color suspended transparent display are calculated from the system parameters. The exposure light intensity is determined according to the proportion of the three-color laser during exposure.
And a second step of: the attenuator is adjusted until the beam intensities of the reference light and the signal light respectively irradiated on the hologram material satisfy the calculated exposure intensities.
And a third step of: the holographic optical element for color suspension transparent display adopts a combined structure, three electronic shutters are opened simultaneously to connect the light path, the electronic shutters are kept open in the calculated exposure time, the electronic shutters are closed to finish exposure, and the obtained color holographic material is subjected to bleaching post-treatment to obtain the combined holographic optical element for realizing color suspension transparent display.
In the third step, the post-treatment of the holographic optical element should be carried out using different treatment methods for the material of the holographic optical element. Such as: the holographic optical element of silver halide emulsion material requires post-treatments of development, water washing, stop-development, fixing, water washing and drying. Holographic optical elements of dichromated gelatin materials require prior use (NH 4 ) 2 Cr 2 O 7 Washing with solution, soaking in hardening liquid of the same kind, washing with water, dehydrating with isopropanol, and finally drying, sealing and solidifying. The holographic optical element of the photopolymer material can be processed by adopting a dry method, and compared with other materials, the holographic image recorded by the photopolymer has higher geometric fidelity, long storage time and difficult distortion.
Embodiment 3 of the present invention provides a method for preparing a laminated holographic optical element for realizing color suspended transparent display by parallel exposure, the specific flow is shown in fig. 10, and the method comprises:
The first step: the exposure position and the inclination angle of the holographic material are determined, and the specific positions of the two lens arrays and other devices are determined according to the position of the holographic material. The exposure time and the exposure intensity required for preparing the holographic optical element for color suspended transparent display are calculated from the system parameters. The exposure light intensity is determined according to the proportion of the three-color laser during exposure.
And a second step of: the attenuator is adjusted until the beam intensities of the reference light and the signal light respectively irradiated on the hologram optical element satisfy the calculated exposure intensities.
And a third step of: the holographic optical element for realizing color suspension transparent display adopts a laminated structure, an electronic shutter corresponding to a laser of the current exposure color is opened, the electronic shutter is kept open in the exposure time calculated in the first step, the exposure is ended by closing the electronic shutter, the holographic material is subjected to bleaching post-treatment, then a new material is cut in a dark environment, and the new material is covered on the material which is just exposed.
Fourth step: repeating the third step until the three colors are exposed and covered, and obtaining the holographic optical element for realizing color suspension transparent display.
In the third step, the post-treatment of the holographic optical element should be carried out using different treatment methods for the material of the holographic optical element. Such as: the holographic optical element of silver halide emulsion material requires post-treatments of development, water washing, stop-development, fixing, water washing and drying. Holographic optical elements of dichromated gelatin materials require prior use (NH 4 ) 2 Cr 2 O 7 Washing with solution, soaking in hardening liquid of the same kind, washing with water, dehydrating with isopropanol, and finally drying, sealing and solidifying. The holographic optical element of the photopolymer material can be processed by adopting a dry method, and compared with other materials, the holographic image recorded by the photopolymer has higher geometric fidelity, long storage time and difficult distortion.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; the technical features of the above embodiments or in different embodiments may also be combined under the idea of the invention, the steps may be implemented in a rational order, and many other variations exist in different aspects of the invention as described above; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.
Claims (13)
1. The holographic optical element for color suspension transparent display comprises a light-transmitting substrate and a color holographic photosensitive film material arranged on the surface of the light-transmitting substrate, and is characterized in that the surface of the color holographic photosensitive film material records two-dimensional array information generated by time sequence exposure or parallel exposure, the two-dimensional array information is formed by synchronously irradiating two coherent point light sources from two sides of the color holographic photosensitive film material, namely the front surface of the color holographic photosensitive film material and the back surface of the color holographic photosensitive film material, at the same position of the color holographic photosensitive film material to generate interference, so as to realize point-to-point superposition exposure, the color holographic photosensitive film material is of a combined structure or a laminated structure, and each coherent point light source is formed by combining three light beams with different colors or formed by time sharing of the light beams with different colors.
2. The holographic optical element of claim 1, in which the color holographic photosensitive film material is a single layer trichromatic composite, or a double layer composite or a triple layer monochromic composite.
3. The holographic optical element of claim 1, wherein incident light from a display image source is incident from a transparent substrate of the holographic optical element, is diffracted by a color holographic photosensitive film material of the holographic optical element after being modulated by diffraction of the holographic optical element, and forms a color two-dimensional virtual image suspended in front of the holographic optical element to enter human eyes; ambient light enters human eyes after being transmitted by the holographic optical element, so that virtual and real image superposition is realized.
4. A holographic optical element for a colour suspended transparent display as claimed in claim 3, in which the holographic optical element is disposed at an oblique angle θ, the display image source being disposed horizontally beneath the holographic optical element, the relative positions of the display image source and the imaging plane and the holographic optical element being determined by the position of the two-dimensional array of dots on the holographic optical element.
5. The hologram optical element for color suspended transparent display according to claim 4, wherein an inclination angle of the hologram optical element with respect to a horizontal direction is in a range of 10 ° to 80 °.
6. A method of manufacturing a holographic optical element for a color suspended transparent display, comprising the steps of:
providing a light-transmitting substrate, and attaching a color holographic photosensitive film material on one surface of the light-transmitting substrate;
the coherent light is divided into two beams, namely a reference beam and a signal beam, and the coherent point light source is formed by combining three different-color light beams or is formed by time-sharing the three different-color light beams;
utilizing one sub-lens in the movable optical module or the lens array to enable the reference beam and the signal beam to form two beams of point light sources, and respectively irradiating the opposite positions of the front and back surfaces of the color holographic photosensitive film material synchronously from the front and back surfaces of the holographic photosensitive film material to form point-to-point superposition exposure;
And moving the two beams of point light sources to perform time sequence exposure or parallel exposure to form exposure points in a two-dimensional array.
7. The method for manufacturing a hologram optical element for color suspended transparent display according to claim 6, wherein an exposure time T of the ij-th point of the hologram photosensitive film material is set ij The following conditions are satisfied:
T ij ＝B/I
wherein B is the exposure of the unit area of the color holographic photosensitive film material, and is determined by the material characteristics; i is the exposure intensity of the holographic photosensitive film material unit, and is determined according to actual requirements.
8. A device for preparing a holographic optical element for color suspended transparent display, characterized in that: the system comprises a first monochromatic laser light source (100), a second monochromatic laser light source (110), a third monochromatic laser light source (120), a beam expansion and collimation system (130), a first reflecting mirror (140), a first dichroic mirror (150), a second dichroic mirror (160), a beam splitter (170), a second reflecting mirror (180), a first moving optical system (190), a third reflecting mirror (210), a second moving optical system (220), a color holographic optical element (200), a first moving platform driving system (230), a second moving platform driving system (240), a total controller (250), a first electronic shutter (260), a second electronic shutter (270), a third electronic shutter (280), a first attenuator (290), a second attenuator (300) and a third attenuator (310);
The method comprises the steps that along the transmission direction of coherent light output by a first monochromatic laser light source (100), a second monochromatic laser light source (110) and a third monochromatic laser light source (120), a first attenuator (290), a second attenuator (300), a third attenuator (310), a first reflecting mirror (140), a first dichroic mirror (150), a second dichroic mirror (160), a beam expansion collimation system (130) and a beam splitter (170) are arranged, the first attenuator (290), the second attenuator (300) and the third attenuator (310) are used for controlling the power of the coherent light output by the first monochromatic laser light source (100), the second monochromatic laser light source (110) and the third monochromatic laser light source (120), the beam expansion collimation system (130) is used for collimating and expanding the coherent light output by the first monochromatic laser light source (100), the second monochromatic laser light source (110) and the third monochromatic laser light source (120) to form parallel light of a beam taking and a wide beam, and the parallel light is divided into two beams through the beam splitter (170), namely, the reflected light as reference light and the transmitted light of the signal light;
the second reflecting mirror (180) and a first moving optical system (190) are sequentially arranged along the transmission direction of the reference light, the first moving optical system (190) is connected with a first moving platform driving system (230), and the first moving optical system (190) is used for irradiating the reference light on a holographic optical element (200) to be prepared and converging behind the holographic optical element (200);
The third reflecting mirror (210) and a second moving optical system (220) are sequentially arranged along the transmission direction of the signal light, the second moving optical system (220) is connected with a second moving platform driving system (240), and the second moving optical system (220) is used for irradiating the signal light on a holographic optical element (200) to be prepared and converging in front of the holographic optical element (200);
the master controller (250) is respectively connected with the first mobile platform driving system (230), the second mobile platform driving system (240) and the first electronic shutter (260), the second electronic shutter (270) and the third electronic shutter (280) and is used for controlling the working states of the first mobile platform driving system (230), the second mobile platform driving system (240) and the first electronic shutter (260), the second electronic shutter (270) and the third electronic shutter (280); and the first moving platform driving system (230) and the second moving platform driving system (240) are controlled, and the positions of the first moving optical system (190) and the second moving optical system (220) are regulated, so that the reference light and the signal light synchronously irradiate the same position of the holographic optical element (170) to be prepared to generate interference, and point-to-point exposure is realized. If the color holographic optical element (200) adopts a combined structure, the master controller (250) controls the first electronic shutter (260), the second electronic shutter (270) and the third electronic shutter (280) to be opened and closed simultaneously according to the motion states of the first moving optical system (190) and the second moving optical system (220), so that the exposure of the two-dimensional array point positions on the holographic optical element to be prepared is completed; if the color holographic optical element (200) adopts a laminated structure, the master controller (250) opens an electronic shutter corresponding to a laser of a corresponding color channel according to the current exposure color, and controls the electronic shutter to be opened and closed according to the motion states of the first moving optical system (190) and the second moving optical system (220), so that the exposure of the two-dimensional array point position on the holographic optical element to be prepared is completed.
9. The apparatus according to claim 8, wherein the first moving optical system (190) comprises a first spatially moving stage (191), and a third mirror (192) and a third lens (193) disposed on the first spatially moving stage (191) in a reference light transmission direction, and the reference light is transmitted through the third lens (193) after being reflected by the third mirror (192) to form a converging spherical wave, irradiated on the holographic optical element (200) to be prepared, and converged behind the holographic optical element (200) to be prepared; the second movable optical system (220) comprises a second space movable platform (221), a fourth reflecting mirror (222) and a fourth lens (223) which are arranged on the second space movable platform (221) along the transmission direction of signal light, the signal light is transmitted through the fourth lens (223) after being reflected by the fourth reflecting mirror (222), and divergent light formed after a focal plane irradiates on the holographic optical element (200) to be prepared and interferes with spherical waves formed after the third lens (193) in the first movable optical system (190) on the holographic optical element (200) to be prepared.
10. The apparatus of claim 8, wherein the first mobile platform drive system (230) is comprised of a first motor (231) and a motor driver (232), and the second mobile platform drive system (240) is comprised of a second motor (241) and a motor driver (242).
11. An apparatus for producing a suspended transparent holographic optical element as claimed in any of claims 8 to 10, characterized in that: the system comprises a first monochromatic laser light source (100), a second monochromatic laser light source (110), a third monochromatic laser light source (120), a beam expansion and collimation system (130), a first reflecting mirror (140), a first dichroic mirror (150), a second dichroic mirror (160), a beam splitter (170), a second reflecting mirror (180), a holographic optical element (200), a third reflecting mirror (330), a first lens array (340), a second lens array (360), a relay optical system (350), a first electronic shutter (260), a second electronic shutter (270), a third electronic shutter (280), a first attenuator (290), a second attenuator (300) and a third attenuator (310);
along the transmission direction of the coherent light output by the first monochromatic laser light source (100), the second monochromatic laser light source (110) and the third monochromatic laser light source (120), the first attenuator (290), the second attenuator (300), the third attenuator (310), the first reflecting mirror (140), the first dichroic mirror (150), the second dichroic mirror (160), the beam expanding and collimating system (130) and the beam splitter (170) are arranged, the first attenuator (290), the second attenuator (300) and the third attenuator (310) are used for controlling the power of the coherent light output by the first monochromatic laser light source (100), the second monochromatic laser light source (110) and the third monochromatic laser light source (120), the beam expanding and collimating system (130) is used for collimating and expanding the coherent light output by the first monochromatic laser light source (100), the second monochromatic laser light source (110) and the third monochromatic laser light source (120) to form parallel light of a wide beam, and the parallel light is divided into two beams, namely reflected light serving as reference light and transmitted light serving as signal light, through the beam splitter (170);
Sequentially placing the second reflecting mirror (180), the third reflecting mirror (260), the first lens array (340) and a relay optical system (350) along the reference light transmission direction, wherein the relay optical system (350) is used for imaging a focus array formed by the first lens array (340) onto a holographic optical element (200) to be prepared;
the second lens array (360) and the holographic optical element (300) to be prepared are sequentially arranged along the signal light transmission direction, the second lens array (360) is formed by arranging a plurality of small lenses and is used for dividing a laser wave front into a plurality of parts in space, each part is focused by the corresponding small lens to form a two-dimensional array consisting of a series of focuses, the two-dimensional array is converged on the holographic optical element (200), and the two-dimensional array is interfered with the focus array formed after the relay optical system (250) on the holographic optical element (200) to be prepared;
the master controller (250) is respectively connected with the first mobile platform driving system (230), the second mobile platform driving system (240) and the first electronic shutter (260), the second electronic shutter (270) and the third electronic shutter (280), and if the color holographic optical element (200) adopts a combined structure, the master controller (250) controls the first electronic shutter (260), the second electronic shutter (270) and the third electronic shutter (280) to be simultaneously opened and closed according to the exposure time required by preparing the holographic optical element (200), so as to complete the parallel exposure of two-dimensional array points on the holographic optical element to be prepared; if the color holographic optical element (200) adopts a laminated structure, the master controller (250) opens the electronic shutters corresponding to the lasers of the corresponding color channels according to the current exposure color until all three colors are exposed, so that the exposure of the two-dimensional array point positions on the holographic optical element to be prepared is finished.
12. The apparatus of claim 8, wherein the relay optical system (350) is comprised of a first relay lens (351) and a second relay lens (352).
13. The apparatus of claim 8 wherein the back focal plane position of the first lens array (340) is in a conjugate relationship to the desired focal array plane position.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311054168.6A CN117192675A (en) | 2023-08-21 | 2023-08-21 | Holographic optical element for color suspension transparent display and preparation device and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311054168.6A CN117192675A (en) | 2023-08-21 | 2023-08-21 | Holographic optical element for color suspension transparent display and preparation device and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117192675A true CN117192675A (en) | 2023-12-08 |
Family
ID=88993302
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311054168.6A Pending CN117192675A (en) | 2023-08-21 | 2023-08-21 | Holographic optical element for color suspension transparent display and preparation device and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117192675A (en) |
-
2023
- 2023-08-21 CN CN202311054168.6A patent/CN117192675A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105116678B (en) | Grenade instrumentation and projection control device | |
| CN108803295B (en) | Method for manufacturing large-field-of-view hologram, display system and dot matrix light source | |
| JP3336200B2 (en) | Three-dimensional image display device having element hologram panel | |
| TWI461735B (en) | Display apparatus | |
| CN106933014B (en) | Optical module | |
| EP0590832B1 (en) | Stereoscopic display apparatus | |
| JP7167348B2 (en) | Multifocal plane display system and device | |
| US20130065159A1 (en) | Color holographic optical element | |
| CN113655615A (en) | Large exit pupil optical display device, near-to-eye display device and image projection method | |
| US20020071178A1 (en) | Stereoscopic image display apparatus | |
| CN106125314A (en) | A kind of light source and laser projection device | |
| CN112925110A (en) | Three-dimensional display module based on light-emitting limited pixel block-aperture pair | |
| CN112346246B (en) | Optical element manufacturing method, beam combiner manufacturing method, and waveguide type optical module | |
| CN113534478A (en) | Optical assembly, display system and manufacturing method | |
| CN117192675A (en) | Holographic optical element for color suspension transparent display and preparation device and preparation method thereof | |
| CN112346172B (en) | Waveguide type optical module, near-to-eye display device, and image projection method | |
| JPH10232592A (en) | Picture recording device and picture reproducing device | |
| CN113534477B (en) | Optical assembly, display system and manufacturing method | |
| CN117111199A (en) | Suspension transparent holographic optical element and preparation device and preparation method thereof | |
| JP5781805B2 (en) | Hologram recording device | |
| US20020191237A1 (en) | Hologram forming melthod | |
| CN211403128U (en) | Processing and copying system of holographic optical device | |
| CN113534455B (en) | Optical assembly, display system and manufacturing method | |
| CN113534476B (en) | Optical assembly, display system and manufacturing method | |
| CN117214987A (en) | Preparation device and preparation method for holographic optical element for directional backlight three-dimensional display |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |