CN108802994A - A kind of image recording system and method - Google Patents
A kind of image recording system and method Download PDFInfo
- Publication number
- CN108802994A CN108802994A CN201810581373.0A CN201810581373A CN108802994A CN 108802994 A CN108802994 A CN 108802994A CN 201810581373 A CN201810581373 A CN 201810581373A CN 108802994 A CN108802994 A CN 108802994A
- Authority
- CN
- China
- Prior art keywords
- light
- mirror
- wave
- image
- hologram
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/36—Microscopes arranged for photographic purposes or projection purposes or digital imaging or video purposes including associated control and data processing arrangements
- G02B21/361—Optical details, e.g. image relay to the camera or image sensor
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/36—Microscopes arranged for photographic purposes or projection purposes or digital imaging or video purposes including associated control and data processing arrangements
- G02B21/362—Mechanical details, e.g. mountings for the camera or image sensor, housings
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/36—Microscopes arranged for photographic purposes or projection purposes or digital imaging or video purposes including associated control and data processing arrangements
- G02B21/368—Microscopes arranged for photographic purposes or projection purposes or digital imaging or video purposes including associated control and data processing arrangements details of associated display arrangements, e.g. mounting of LCD monitor
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Holo Graphy (AREA)
Abstract
This application involves a kind of micro-image record system and recording methods.The record system is divided into two bundles light wave by the light for sending out laser, wherein the information of a branch of light wave belongings body, in addition a branch of light wave forms spherical light wave after beam-expanding collimation using microcobjective；Interference forms hologram to two-beam wave on CCD after light combination mirror, and is reproduced by computer to obtain the three-dimensional microscopic image of object to the interference pattern.The computer can automatically control the rotation of light combination mirror, to adjust the core position of spherical light wave, so as to get reproduction image in original image just detached with intermediate distracter, to obtain the reproduction image of high quality.
Description
Technical field
This application involves a kind of records of micro-image, belong to optical imaging field.
Background technology
Common microscope, is mainly obtained by lens group, and the micro-image being achieved in that can not record preservation, observation
The details of image is not remembered clearly soon afterwards.With the continuous development of semiconductor technology and laser technology, occur at this stage
A kind of digital microscope can obtain the position phase images of imaging object while obtaining the intensity image of imaging object, or
Person says that it can obtain the 3-D view of imaging object, and can be by the permanent preservation of the 3-D view of acquisition.
Digital microscope technology also known as digital holography acquire the hologram of imaging object with CCD, and hologram is inputted and is counted
In calculation machine, the actual hologram reconstruction process of algorithm simulation is utilized in a computer, to rebuild the three of object in a computer
Tie up image.The reproduction image of the image that the reproduction image of hologram is obtained relative to common digital camera, hologram is strong in addition to having
It spends outside image, also position phase images, i.e. the three-dimensional appearance image of object, therefore in digital holography it is crucial that object position phase
The reconstruction of information.It is most of that digital hologram, off-axis gaussian beam are obtained by the way of off-axis gaussian beam in existing digital holography
Record system in, be divided into two-beam after beam splitter from the laser being emitted in laser, it is a branch of to be taken after object (sample)
Information (therefore referred to as Object light wave) with object reaches CCD target surfaces after light combination mirror BS, and another beam (being referred to as reference light wave) is through expanding
Through speculum M after beam collimation2Reflection, then it is (i.e. complete through light combination mirror reflection arrival CCD target surfaces and object light wave interference formation interference image
Breath figure).In the prior art, off-axis digital holography is broadly divided into off-axis Fresnel digital hologram and off-axis lensless fourier transform
Digital hologram, in the record of off-axis Fresnel digital holography, reference light uses plane light wave, when recording number with Plane reference light wave
When word hologram, the structure of record system determines that subregion interference fringe frequency is low in interference optical field, subregion frequency
Rate is high so that the bandwidth of CCD cannot be fully utilized, and recording distance is limited by CCD photosurface sizes, point of reproduction image
Resolution is difficult to improve.
Invention content
The application provides a kind of micro imaging system, and digital hologram is recorded using spherical reference wave, to improve again
The resolution ratio of phenomenon.
The application uses following technical scheme：A kind of micro-image records system, including laser 1, the first half-wave plate 2,
Polarizing beam splitter mirror 3, the first speculum 4, the first beam-expanding collimation mirror 5, transparent substance 6, light combination mirror 7 (half-transmitting and half-reflecting), CCD8,
Second half-wave plate 9, the second beam-expanding collimation mirror 10, the second speculum 11, microcobjective 12 and computer 13；What laser was sent out
Light beam is divided into light beam A and light beam B after polarizing beam splitter mirror, and light beam A enters shape after the first beam-expanding collimation mirror after the first speculum
Object light wave is formed at directional light irradiation transparent substance, which reaches CCD target surfaces after penetrating light combination mirror；After polarizing beam splitter mirror
Light beam B form plane light wave by the second half-wave plate and the second beam-expanding collimation mirror 10, the plane light wave is anti-by second
Penetrate mirror enter microcobjective formed spherical reference wave, the spherical reference wave center be reference point source, the spherical surface
Reference light wave reaches CCD target surfaces after light combination mirror and forms hologram with Object light wave；The hologram of the CCD records is transmitted to calculating
Machine simultaneously preserves, and the computer can automatically control the rotation of light combination mirror, to control the position of reference point source, to obtain most
Good hologram, original image, conjugate image and intermediate distracter are rigid in the reproduction image that can be obtained after the interference pattern is reconstructed
Good separation.It is characterized in that：Further include angular adjustment system, the angular adjustment system includes：Support platform, rotary shaft, drawing
Rope, displacement detector, driving motor；Light combination mirror is fixed in support platform, by the rotation of rotary shaft, drives light combination mirror rotation
Turn, to adjust reference point source in the position of object plane, the rotation of rotary shaft drives the displacement of drawstring, the displacement distance of drawstring
It is monitored by displacement detector, the displacement distance of drawstring is obtained by displacement detector, and then obtain the rotation angle of rotary shaft.
The application records hologram using spherical reference wave, and the fringe spatial frequency of interference field is relatively low, to make
The sampling condition of digital hologram record readily satisfies, and especially arranges and remembers according to the method for self imaging without lenses
When recording light path, since interference fringe is equal close to parallel and spacing, the finite bandwidth of CCD can be made full use of.And allow
Smallest record distance do not limited by CCD sizes, for small items can with the distance of very little record hologram, obtain more
More information is conducive to the raising of reproduction image resolution ratio, therefore digital with spherical reference wave record lensless fourier transform
Hologram is the effective way for realizing high-resolution imaging.
Description of the drawings
Fig. 1：The coordinate schematic diagram of spherical reference wave digital hologram record；
Fig. 2：Off-axis lensless fourier transform digital holography recording system；
Fig. 3：Angular adjustment automatic control system.
Specific implementation mode
The recording beam path of spherical reference wave digital hologram and the coordinate system used in analysis are as shown in Figure 1, wherein
x0-y0Plane is object plane, and x-y plane is holographic plan, and z-axis is perpendicular through two planar centrals, with reference to the position coordinates of point source
For (xr,yr,zr), wherein zrDistance of the expression point source to CCD planes.In practical applications, z is often takenr>z0。
According to means of Fresnel diffraction, under paraxial approximate condition, ignores constant phase factor, reach the object of CCD planes
Light wave and reference light wave are respectively
The item that original image is represented in hologram is UO*, obtained after arrangement
Wherein
The position phase of each point and the fringe spatial frequency along x, y both direction are respectively in diffractional field
In view of z0、zrIt is just and zr≥z0, then the minimum and maximum spatial frequency of holographic fringes be respectively
According to Nyquist sampling theorem, it is desirable that
It can be obtained by formula (1-8), (1-9) as follows to the restrictive condition with reference to added by optical biasing to meet sampling theorem：
Halo light | U |2Spatial frequency along the maximum value of x, y director space frequency be respectively for
In order to make reproduction image be separated from each other, as long as appropriately the position of setting reference light makes Zero-order diffractive item, original image and is total to
The frequency spectrum non-overlapping copies of yoke picture, that is, require
To obtain in spherical reference wave off-axis gaussian beam, to another restrictive condition of reference light source position setting, i.e.,
The separation condition of reproduction image is
It is that can determine the position in reference point source in conjunction with (1-10) formula, z in formularSize be by the enlargement ratio to reproduction image
It is required that and reproduce reference light wave form codetermine.
Recorded in hologram method using spherical reference wave, using it is more be off-axis lens-less Fourier transform holography
And coaxial phase shift lens-less Fourier transform holography.It seems to be separated from each other that the advantages of off-axis light path, which is zero level, positive and negative first-order diffraction,
, distracter, which filters out, to be easier, and can be rebuild by single holographic figure.Off-axis lens-less Fourier transform holography is carried out below
It discusses.
Off-axis lens-less Fourier transform holography is one of common recording beam path structure in Digital Holography.Off-axis nothing
Lens Fourier transformation digital holography recording system as shown in Fig. 2, including laser 1, the first half-wave plate 2, polarizing beam splitter mirror 3,
First speculum 4, the first beam-expanding collimation mirror 5, transparent substance 6, light combination mirror 7 (half-transmitting and half-reflecting), CCD8, the second half-wave plate 9,
Second beam-expanding collimation mirror 10, the second speculum 11, microcobjective 12 and computer 13；The light beam that laser is sent out is through polarization point
Shu Jinghou is divided into light beam A and light beam B, and light beam A forms directional light irradiation after entering the first beam-expanding collimation mirror after the first speculum
Transparent substance forms Object light wave, which reaches CCD target surfaces after penetrating light combination mirror；Light beam B after polarizing beam splitter mirror passes through
Second half-wave plate and the second beam-expanding collimation mirror 10 form plane light wave, and the plane light wave enters micro- by the second speculum
Object lens form spherical reference wave, the center of the spherical reference wave is reference point source, the spherical reference wave economic cooperation
Shu Jinghou reaches CCD target surfaces and forms hologram with Object light wave.Record is located at reference to point source on object plane at this time, zr=z0, substitute into
(1-10) formula and (1-13) formula, are met the offset requirements of sampling condition and reproduction image separation condition simultaneously
Wherein equal sign indicates that critical separation and Critical Sampling, solution can obtain smallest record distance
z0min=max (4X/ λ Δs x, 4Y/ λ Δs y) (1-15)
Max expressions take value larger in the two in formula.
From the separation degree of the reproduction image of the visible lens-less Fourier transform holography of analysis above and reference point source
Coordinate is related, is not related to the angle of Object light wave and reference light wave.However, passing through the analysis to recording beam path, it is known that micro- object
The reference point source that mirror indicates is mirror symmetry relative to the semi-transflective reflective minute surface of light combination mirror with object, that is to say, that reference
Point light source is in the same plane by the imaging of semi-transflective reflective minute surface and object, and during light path arrangement, due to
Object light wave is all parallel table top arrangement with reference light wave, i.e. the y-coordinate of reference point source may be considered zero, at this point, without lens
The separation degree of the reproduction image of Fourier Transform Hologram is only related to the x coordinate of reference point source, and can by rotating light combination mirror
To change the x coordinate of above-mentioned point light source, and then influence the separation degree of reproduction image.In order to be sufficiently separated and resolution ratio is maximum
Reproduction image, a kind of accurate reference point source that adjusts is described below and sits calibration method；Specifically comprise the following steps：
1) light combination mirror is measured to the first distance d of CCD target surfaces1And it records；
2) it acquires the first hologram of Object light wave and reference light wave and preserves；
3) the first hologram is rebuild to obtain reproduction image 1, original image and intermediate interference in the reproduction image 1 judged
The degree of item separation；
4) if the original image in reproduction image 1 and intermediate distracter are overlapped or partly overlap, computer sends out instruction control
Angle (such as 0.1 degree) as defined in light combination mirror rotation；
5) continue to acquire the second hologram of Object light wave and reference light wave and preserve；
6) the second hologram is rebuild to obtain reproduction image 2, original image and intermediate interference in the reproduction image 2 judged
The degree of item separation；
If 7) original image and intermediate distracter still partly overlap in reproduction image 2,4) -6 are repeated the above steps), directly
It is kept completely separate to the original image in reproduction image with intermediate distracter；
8) reproduction image being kept completely separate to original image and intermediate distracter continues to judge, if original image and intermediate distracter
The distance between it is too far, then computer send out instruction control half-reflecting half mirror negative direction rotation as defined in angle half (such as
0.05 degree)；
9) continue to acquire the third hologram of Object light wave and reference light wave and preserve；
10) third hologram is rebuild to obtain reproduction image 3, original image and centre are dry in the reproduction image 3 judged
Disturb the degree of item separation；
If 11) the distance between original image and intermediate distracter are still too far, 8) -10 are repeated the above steps), until
Original image and intermediate distracter in reproduction image just detach；Corresponding hologram is d at this time1Apart from corresponding best hologram
H1；By the best hologram H1It preserves in the database；
12) control CCD is moved forward or rearward predetermined distance Δ d, then repeats the above steps 1) -11), until obtain with
Distance d1The corresponding best hologram H of ± Δ d2, by the best hologram H2It preserves in the database.
13) by the best hologram H of acquisition1、H2…HnWith corresponding distance d1、d2…dnDistance-hologram is established to correspond to
Table.
14) in the record of follow-up hologram, from calculating after the distance d of measurement CCD to light combination mirror first, transmission range d
Above-mentioned distance-hologram in machine, which corresponds to, recalls required best hologram H in table, as standard hologram；Secondly, computer
Hologram M is shot after sending out instruction control light combination mirror rotation angle, hologram M is matched with above-mentioned standard hologram
(identifying) continues rotation angle shooting hologram if hologram mismatches；If hologram matches, will clap at this time
The hologram M taken the photograph is preserved, as the hologram for rebuilding object three-dimensional image.In the matching process of above-mentioned hologram, due to two width
Completely the same hologram is difficult to accomplish, therefore an error threshold can be arranged, when matched error amount is less than above-mentioned threshold
Value, it may be considered that being matched, then mismatches more than above-mentioned threshold value.
The application due to, with apart from corresponding best hologram, and establishing distance-hologram by acquisition and corresponding to table, with
During rear digital microscope system is adjusted, the distance that CCD arrives light combination mirror need to be only inputted, computer system automatically controls light combination mirror and revolves
Turn and obtain best hologram, pass through the best hologram, it will be able to obtain more accurately 3-d reproduction picture.
Further, the application also provides a kind of angular adjustment accurately controlling light combination mirror rotation angle by computer
System.As shown in figure 3, the angular adjustment system includes：Support platform 14, drawstring 16, displacement detector 17, is driven at rotary shaft 15
Dynamic motor 18.Light combination mirror is fixed in support platform, by the rotation of rotary shaft, light combination mirror rotation is driven, to adjust reference
For point light source in the position of object plane, the rotation of rotary shaft drives the displacement of drawstring, the displacement distance of drawstring to pass through displacement detector
Monitoring is obtained the displacement distance of drawstring by displacement detector, and then obtains the rotation angle of rotary shaft, due to the movement of drawstring
Distance can be displaced by detector and accurately obtain, and in an a diameter of steady state value for rotary shaft, the angle of rotary shaft rotation
It can accurately be obtained.Computer 13 controls driving motor driving rotary shaft rotation and is driven during rotary shaft rotates
Drawstring displacement, displacement detector detect the straight-line displacement of drawstring, and when straight-line displacement is equal to preset value, displacement detector sends out letter
It number to computer and then controls rotary shaft and stops rotating, the predetermined angular that the preset value and light combination mirror needs rotate is corresponding.It is logical
Above-mentioned angular adjustment system is crossed, can accurately adjust and join in above-mentioned off-axis lensless fourier transform digital hologram record
The position of examination point light source controls the separation degree and resolution ratio of reproduction image, to obtain the reproduction image of high quality.
Claims (3)
1. a kind of micro-image records system, including laser, the first half-wave plate, polarizing beam splitter mirror, the first speculum, the first expansion
Beam collimating mirror, transparent substance, light combination mirror (half-transmitting and half-reflecting), CCD, the second half-wave plate, the second beam-expanding collimation mirror, the second reflection
Mirror, microcobjective and computer；The light beam that laser is sent out is divided into light beam A and light beam B, light beam A warp after polarizing beam splitter mirror
Directional light irradiation transparent substance formation Object light wave is formed after entering the first beam-expanding collimation mirror after first speculum, which penetrates
Reach CCD target surfaces after light combination mirror；Light beam B after polarizing beam splitter mirror is formed by the second half-wave plate and the second beam-expanding collimation mirror
Plane light wave, the plane light wave enter microcobjective by the second speculum and form spherical reference wave, the spherical reference
The center of light wave is reference point source, and the spherical reference wave reaches CCD target surfaces after light combination mirror and forms holography with Object light wave
Figure；The hologram of the CCD records is transmitted to computer and preserves, and the computer can automatically control the rotation of light combination mirror,
To control the relative position of reference point source and plane where transparent substance, to obtain best hologram, the best holography
Scheme it is reconstructed after in the reproduction image that can obtain original image, conjugate image and intermediate distracter just detach.It is characterized in that：Also
Including angular adjustment system, the angular adjustment system includes：Support platform, rotary shaft, drawstring, displacement detector, driving electricity
Machine；Light combination mirror is fixed in support platform, by the rotation of rotary shaft, light combination mirror rotation is driven, to adjust reference point source
In the relative position of object plane, the rotation of rotary shaft drives the displacement of drawstring, the displacement distance of drawstring to be supervised by displacement detector
It surveys, the displacement distance of drawstring is obtained by displacement detector, and then obtain the rotation angle of rotary shaft.
2. analysis of digital microscopy images as described in claim 1 records system, it is characterised in that：Computer controls driver driving rotation
Shaft rotates, and during rotary shaft rotates, drives drawstring displacement, displacement detector detects the straight-line displacement of drawstring, when straight
When displacement of the lines is equal to preset value, displacement detector sends out signal, and to computer, control rotary shaft is stopped rotating in turn, described default
Value needs the predetermined angular rotated corresponding with light combination mirror.
3. a kind of micro-image recording method records system using the micro-image described in claims 1 or 22, records the object
The best hologram that light wave and the reference light wave are formed, the reproduction image Central Plains that can be obtained after the best hologram is reconstructed
Beginning picture, conjugate image and intermediate distracter just detach.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810180221 | 2018-03-05 | ||
| CN201810180221X | 2018-03-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108802994A true CN108802994A (en) | 2018-11-13 |
| CN108802994B CN108802994B (en) | 2020-06-26 |
Family
ID=64087673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810581373.0A Active CN108802994B (en) | 2018-03-05 | 2018-06-07 | Image recording system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108802994B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114593670A (en) * | 2022-01-25 | 2022-06-07 | 华南师范大学 | Implanted coaxial and off-axis digital holographic switching device based on Rochon prism |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102749834A (en) * | 2012-07-24 | 2012-10-24 | 河北工程大学 | Optical microscopic imaging system and imaging method |
| CN104024835A (en) * | 2011-11-17 | 2014-09-03 | 东丽工程株式会社 | Automatic visual inspection device |
| US9541374B2 (en) * | 2007-12-31 | 2017-01-10 | Stc.Unm | Structural illumination and evanescent coupling for the extension of imaging interferometric microscopy |
-
2018
- 2018-06-07 CN CN201810581373.0A patent/CN108802994B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9541374B2 (en) * | 2007-12-31 | 2017-01-10 | Stc.Unm | Structural illumination and evanescent coupling for the extension of imaging interferometric microscopy |
| CN104024835A (en) * | 2011-11-17 | 2014-09-03 | 东丽工程株式会社 | Automatic visual inspection device |
| CN102749834A (en) * | 2012-07-24 | 2012-10-24 | 河北工程大学 | Optical microscopic imaging system and imaging method |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114593670A (en) * | 2022-01-25 | 2022-06-07 | 华南师范大学 | Implanted coaxial and off-axis digital holographic switching device based on Rochon prism |
| CN114593670B (en) * | 2022-01-25 | 2023-07-04 | 华南师范大学 | Implanted coaxial and off-axis digital holographic switching device based on Rochon prism |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108802994B (en) | 2020-06-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20140347672A1 (en) | Apparatus and method for quantitive phase tomography through linear scanning with coherent and non-coherent detection | |
| CN106769701B (en) | A kind of particle sphericity coaxial digital holography detection device and detection method | |
| CN105973164B (en) | A kind of Digital holographic microscopy method based on pixel polarization chip arrays | |
| CN108169888B (en) | Digital microscopic imaging system and method | |
| CN108519728A (en) | A kind of high resolution ratio digital holographic Diffraction tomography | |
| CN106054570B (en) | Intensity transmission equation realizes the larger Phase Build Out method of single digital hologram | |
| TWI797377B (en) | Surface shape measuring device and surface shape measuring method | |
| CN101482503B (en) | Coherent diffraction imaging method and its processing equipment | |
| CN104089573B (en) | Multichannel white light common path interference micro tomography system based on crossed polarized light | |
| CN103323938B (en) | A kind of method obtaining stereo microscopic image | |
| JP2017122890A (en) | Three-dimensional imaging apparatus and imaging method using digital holography | |
| CN102944989B (en) | Phase-shift digital holographic high-speed imaging method and system | |
| CN112525104B (en) | Digital holographic three-dimensional shape measuring device and method | |
| JP2010200188A (en) | Multi-viewpoint image generation apparatus, multi-viewpoint image generation method, and multi-viewpoint image generation program | |
| CN102954757A (en) | Microscopic interference detecting device based on synchronous carrier phase shift and detecting method of microscopic interference detecting device | |
| CN108802994A (en) | A kind of image recording system and method | |
| CN107356195A (en) | Three view field digital holographic detection devices and method based on two-dimension periodic grating and point diffraction | |
| CN107421437B (en) | Three view field digital holographic detection devices and method based on two-dimensional phase grating and point diffraction | |
| CN113777767A (en) | Optical tomography microscopic imaging system and method for rapidly and continuously rotating sample | |
| CN109974578B (en) | Vortex digital holographic microscope system based on double liquid crystal spatial light modulators | |
| CN108594616A (en) | A kind of optical imagery record demo system and method | |
| CN112630232B (en) | Method and device for detecting defects of inner surface and outer surface of differential confocal fixed-surface interference target pill | |
| CN115598147A (en) | Device and method for detecting defects on inner and outer surfaces of microsphere based on white light microscopic interference | |
| CN112683918B (en) | Method and device for detecting inner surface defects of differential confocal fixed-surface interference target pellet | |
| CN108594617A (en) | The big view field imaging recording method of incoherent digital hologram and device |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |