JPH0125067B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the field of non-destructive testing.

The use of interference holography in non-destructive testing is well known. It is also known to develop the hornographic film used in the test to expedite the testing process. See, eg, US Pat. No. 3,739,702. This patent shows water being introduced into the developing chamber during imaging of the film. Film development in an apparatus that exposes the film, develops it, and projects an image of the developed film is described in U.S. Pat. No. 3,200,724, which is incorporated herein by reference. In this patent,
Water is used in the development chamber to improve light transmission through the equipment holding the film and to prevent the film from drying out after development and before it is protected.

The present invention is highly flexible, convenient for use in double exposures, and has instant holographic coherence.
It also has a structure with excellent film retention and developability. The present invention solves a significant problem inherent in the prior art in that it can be used in any spatial orientation.

According to the invention, a holographic device for detecting flaws has a photographic station supporting a photosensitive medium. The photographic station, along with the photosensitive medium, is transparent with a depth ranging from about 0.127 mm (0.005 inch) to about 3.175 mm (0.125 inch), preferably from about 0.127 mm (0.005 inch) to about 2.03 mm (0.080 inch). A developing chamber with a surface is formed. The peripheral contour of the development chamber is preferably circular, with a shape that constantly varies by an angle of about 115 degrees or more, advantageously more than 125 degrees. This is to ensure that the liquid introduced there forces out all the liquid already in the chamber. It is therefore necessary to ensure that when washing away the developer solution with water, no residual developer solution remains so that it does not result in premature development. In order to ensure that such problems such as premature development do not occur, the shape is expressed in this specification as being constantly changing at an angle of about 115° or more, as described above. Therefore, for example, a square shape would be unsuitable, and a circular shape would be preferable. An attached hydraulic device supplies fluid to and exhausts the developer chamber. A laser beam directs a coherent beam of light onto the object to be tested for reflection to a photographic station. A reference beam is directed toward a photographic station. For use in the field for inspecting pipes, the device advantageously includes a housing and a pair of saddles, each having a portion for receiving pipes of different diameters and a strap fastening device. Photographic stations can develop photosensitive media in situ and can be used in any spatial orientation. The invention also includes a photo station itself that does not use a laser beam.

Due to the construction of the developer chamber, the liquid entering the developer chamber by capillary action, independent of its spatial orientation, drains out all the fluid already in it. This prevents the film from developing prematurely due to residual amounts of processing solution, or from diluting the developer anywhere in the processing chamber with the inflow liquid. Make it.
The geometry of the developer chamber periphery ensures that adhesion between the developer chamber and the liquid contained therein does not create a liquid pocket that is left in the chamber when it is desired to drain the liquid. This development chamber minimizes the amount of developer required for the development process.

The present invention will be explained below with reference to the drawings.

The hologram device 2 according to the invention has a frame 4 to which a pair of saddles 8, 8 are fixed, each saddle 8 having an arcuate recess 10 adapted to receive a pipe 12 (FIG. 2). Further, the saddle 8 has a pair of recessed portions 10A and 10B in an arc having a larger radius than the recessed portion 10 for receiving a pipe of a larger diameter. In FIG. 4, dashed lines 12A indicate pipes of various diameters supported on saddle 8 at points 10C and 10D. As shown in FIG.
10E and 10F show large diameter pipes supported on the saddle 8, with wider spans to provide more stable support for the saddle 8 and the hologram device. Pipe size 12 or smaller is accommodated in a recess 10 in each saddle 8.

A yoke 18 is pivotally attached to each saddle 8, as indicated at 20. One end 2 of strap 26
4 is fixed to the yoke 18 as indicated by 28. A second yoke 32 is pivotally mounted at 34. A yoke 36 having a pin 40 is pivotally attached to the lever (yoke) 32. Second strap 4
One end 44 of 6 is fixed to the pin 40. A normal adjustable buckle 48 is attached to straps 26 and 46.
and are removably connected.

A laser device 60 is mounted on frame 4 and connected to a power source indicated at 62 (FIG. 1). Laser device 60 may be a helium-neon laser with a power output of 10 milliwatts. for example
YAG laser, krypton laser, _CO2 laser,
Alternatively, any laser known in the art for holographic nondestructive testing may be used, such as a nitrogen laser. A continuous wave laser operating in TEM mode should be used. The laser is about 1
It is convenient to have an output of from 20 milliwatts.

The beam from the laser device is shown at 64 (Figure 1).
directed toward a mirror, which directs the beam downward to mirror 66, which directs the beam to mirror 68. The mirror 68 is a metal plate 7
0, and the plate 70 is fixed to a rod 72 which is laterally pivoted to the frame 4. Rod 7 to pivot mirror 68
A handle 78 integral with 2 is used. A magnet 79 mounted on a housing 81 having a chamfered surface 80 and shown in phantom in FIG. 1 holds plate 70 and mirror 68 in the position shown in FIG. In this position, the mirror 68 directs the laser beam to the pipe 12.
is reflected downward toward the coupling ring 82 that connects to the pipe 84. A portion of the laser beam is reflected from mirror 68 to reference beam mirror 90;
It is then reflected to the photo station 86.

The laser beam is controlled by a shutter 94 having an arm 96 (FIG. 2) adapted to cut off the beam emanating from the laser device. Arm 9
6 is secured to a pivot plate 98 (FIG. 2) which urges the shutter into the closed position by an extension spring 100. The pivot plate 98 is actuated by a solenoid 102 which, when actuated, opens the shutter 94 and provides an optical path from the laser to the mirror 64.

The photo station 86 includes a transparent plate 12 made of synthetic resin such as acrylic, polycarbonate, fluorinated resin, or polystyrene resin.
0 (Fig. 8). A plate 120 is fixed to the frame 4 over an opening 122 in the frame 4. The circular groove 124 receives therein a ring gasket 126, for example made of rubber, which is circular in cross section and extends slightly above the top of the plate 120. A pair of bars 130 and 1
32 is attached to the top 12 of the plate 120 by adhesive.
It is fixed at 8. For example, a transparent plate 136 made of one of the aforementioned synthetic resins overlaps the plate 120 between the bars 130 and 132, and pins 142, 144 (FIG. 7).
It is pivotally attached to the yoke frame 140 by. Yoke 140 is pivotally connected to block 132 by pins 146 and 148. A horizontal bar 152 of the yoke 140 is fixed to a plate 154 with adhesive, and the plate 154 is fixed with adhesive to a block 156 through which a screw 157 is passed.
is pivotally connected to the plunger 158 of the solenoid 160. Plunger 158 fits loosely into opening 161 in block 156. Solenoid 160
is attached to the post 162 and the plunger 158
split ring 168 fixed in groove 170 of
presses the plunger 158 downward, and the plate 1
Press 36 downward.

Ordinary film cartridge 180 (Figure 7)
is the cartridge holder 1 attached to the frame 4
It is rotatably supported by 82 and supplies a film 184, which is wound onto a reel 186. The film 184 is advantageously a high resolution film such as Kodak 649F manufactured by Eastman Kodak Company. Reel 186 has spring steel tab 190 and hub 1
94 and rotatably mounted on a cone 188 mounted on the cone 188. The hub 194 is connected to the motor 2
It is splined to a spindle 196 which is driven by the 00. Film 184 is placed between plate 136 and gasket 126. Film 184, gasket 126 and plate 120 form a very narrow developer chamber 210. The developing chamber is approximately 0.127 mm (0.005 inch)
Between 3.175 mm (0.125 inch), preferably about
0.127 mm (0.005 inch) to approximately 2.03 mm (0.080 inch)
(i.e., the distance between the emulsion coated side of film 184 and plate 120). Its depth starts from approximately 0.381 mm (0.015 inch)
0.635 mm (0.025 inch) is advantageous, and the chamber formed is circular.

Plate 120 has a supply conduit 214 (FIG. 7) having a reduced diameter portion 216 in communication with developer chamber 210 and a discharge conduit 218 having a reduced diameter portion 220 in communication with developer chamber 210.
The small diameter portions 216 and 220 are in the developing chamber 2.
10 and are diametrically opposed to each other and communicate with the developing chamber 210. The small diameter of these conduits prevents liquid from exiting the developer chamber 210 when the pump is not operating. Advantageously, the diameters of these conduits range from about 0.79 mm (1/32 inch) to 5.56 mm (7/32 inch);
is preferably larger than that of .

Conduit 214 is connected to piping 230 (FIG. 9), which is connected to a vent pipe 232 that includes a check valve 234 to prevent fluid from being pumped into developer chamber 210 from the vent pipe. Prevent backflow.
Pipe 230 is connected to valves 238 and 24 by pipe 236.
0. Valve 236 is a two-position valve that connects pipe 244 to pipe 236 or 246.
246 in its normal position.
Connect to. The pipe 244 has a check valve 250,
It is connected to a pump 252 which is connected to a supply tank 256 by a line 254. The supply tank 256 has a vent 257;
There is 258 ounces of water in it. The pipe 246 has a check valve 264 and is connected to a discharge pipe 266.
A drain pipe 266 drains fluid into a tank 268 having a vent 269 . Piping 244 and 266 are long and resilient to allow pump 252 and tanks 256 and 268 to be located at remote locations separated from the main body of the holographic device.
Valve 240 is connected to piping 272 to piping 246
and piping 274. Valve 240 is a two-way valve that connects pipe 274 to either pipe 272 or 236, and to pipe 272 in its normal position. Piping 274 is check valve 2
76 and is connected to pump 278 . Pump 278 connects tank 28 with vent 286.
The developer-fixing solution (monobath) is pumped up from 4. A typical monobus is the Eastman Kodak Company's Kodak 448. Because the piping 274 is long and elastic, the pump 278 and tank 284 can be located at remote locations away from the main part of the hologram device 2.

Drain pipe 218 is connected to piping 290 which is connected to a pump 292 that discharges liquid to drain pipe 266.
It is connected to the. The pump 292 is, for example, a rubber vane type pump, and does not allow fluid to pass through when stopped. Line 294 includes a check valve 296 and is connected in parallel with pump 292 to bypass it. A quick disconnect fitting 295 (FIG. 2) is provided for piping 244, 266 and 274.

Referring to FIG. 10, the hologram device 2 is energized by a 12 volt battery designated 300, the positive side of which is connected to a wire 310 containing a main switch 312, and the negative side of the battery connected to a wire 310 containing a main switch 312.
14. Power supply 62 is connected to wiring 310 by wiring 316 and connected to wiring 318,
It is connected to the negative side of battery 300 via 320 and 314. Laser device 60 is connected to power source 62 by wires 322 and 324. A timer switch 330 having an instant start switch 334 controls the shutter solenoid 102. Timer 330 is connected to wiring 3 by wiring 332.
20 and is connected to the wiring 310 by a wiring 336. Timer switch 330 controls shutter solenoid 102, which is connected by wires 340 and 338. In addition, the solenoid 102
can also be activated by closing switch 400 at wire 310, which is connected to wire 338. The wiring 340 is connected to the wiring 332 via a wiring 346. timer 330 is 350
It is controlled by a photovoltaic cell shown in .

Microprocessor 302 is programmed to perform the necessary sequence operations. It is common to use microprocessors for sequence operations. Other devices may be used, such as mechanical stepping switches. The microprocessor 302 is connected to the wiring 310 by the wiring 360 and to the wiring 314 by the wiring 362.
It is connected to the. Dotted lines 370, 371, 37
As shown at 2,374 and 376, motor 2
00, solenoid 160, pump 252, 278
and 292 are each controlled by microprocessor 302. Similarly, dotted line 3
80 and 382 direct output control by microprocessor 302 to valves 238 and 240, respectively. Motor 200, solenoid 16
0, quick disconnect fitting 386 to connect wiring to solenoid 102 and power supply 62 to the rest of the circuit.
(Fig. 2) is provided.

The operation of the present hologram device 2 will become clear from the following description. The device 2 has a pipe 12 received in an arcuate portion 10 of a saddle 8 and a strap 2.
It is attached to the pipe in a fixed state by 6 and 26.

To start the device, place the film cartridge 180 in the film holder 182 (second
), the film 184 is passed between the gasket 126 and the plate 136, while the plunger 158 of the solenoid is lifted upward by hand to remove the plate 13.
6 above the gasket 126. Thread the film onto reel 186, release plunger 158, and plate 136 pulls the film through gasket 1.
26 so that it can be held firmly.

Switch 312 is closed to energize laser device 60 and apply power to microprocessor 302. Shutter 94 prevents the laser beam from reaching mirror 64.

Momentary switch 301 is closed and microprocessor 302 is started. Pumps 252 and 278 (FIG. 9) are then activated for a predetermined period of time, for example 5 seconds, to cause water to flow through lines 254, 244, 246 and 266 to drain tank 268. At the same time, Monobus pipes 280, 274, 272, 2
66 to a discharge tank 268. The purpose of this operation is to expel air from the liquid supply system.

Momentary switch 304 is then closed to allow microprocessor 302 to energize solenoid 160, lifting plunger 158 (FIG. 8) and pivoting frame 140 (FIG. 9) to lift plate 136. , then gasket 126
The distance slightly larger than the inner diameter of the film 184
The motor 200 is energized for a sufficient time to send .
Once the motor 200 is stopped, the microprocessor discharges the solenoid 160 so that the spring 166 causes the plunger 158 to move downwardly, pivoting the frame 140 and lowering the plate 136 onto the film, causing the film to pass through the gasket 126.
hold against. Pivoting of plate 136 by pins 142 and 144 ensures that plate 136 is parallel to gasket 126 and evenly presses the film against the gasket.

After the above operations are completed, microprocessor 302 activates pump 252 (FIG. 9) and valve 238 to allow water to be pumped into developer chamber 210. The circular shape and small depth of the development chamber utilizes the surface tension of the liquid to provide capillary action and reduce the small diameter portion 21 of the supply conduit 214.
Even if the device 2 is placed in a spatial orientation such that 6 is located at the top of the developing chamber 210, the incoming liquid is ensured to force all outflow from the developing chamber 210. In this way, even if the apparatus is placed in any direction, the water pumped into the developing chamber 210 through the piping 244, valve 238, piping 236, and piping 230 will not flow through the piping 218, piping 290, 290.
4 and 266, all the air in the developing chamber 210 is forced into the exhaust tank 268. During this operation, the pump 292, when at rest, blocks the flow of fluid through it, creating a water seal. When the developer chamber 210 is filled with water, the microprocessor 302 stops the pump 252 and
Valve 238 is released and temporarily deactivated.

Momentary switch 334 is now closed, activating timer switch 330, which immediately activates shutter solenoid 102.
The laser beam passes through mirrors 64, 66 and 68 (first
(FIG. 8) to coupling ring 82 and then through opening 122 to film 184 (FIG. 8).
so that it is reflected upwards. The timer 330 changes the energization time of the solenoid 102 by measuring the illuminance of the light beam reflected by the photovoltaic cell 350 . Timer switch 330 forces spring 100 to close shutter 96, causing the laser beam to close slightly.
After solenoid 102 is released, coupling 82 is stressed, for example by pressurizing the piping system including pipes 12 and 84. Switch 334 is then used again to activate timer switch 330 and expose film 184 again.

After the shutter closes, the momentary switch 304 closes again and begins developing and fixing the film. Microprocessor 302 processes pump 278 and valve 240.
(Fig. 9) to operate the pipes 280, 274 and valve 2.
40, Monobus 2 via piping 236 and 230
82 to the developing chamber 210 and replace it with the water in it.
66 into a discharge tank 268. Developing chamber 2
10 allows all water to be drained from the developing chamber. Microprocessor 302 then deactivates pump 278 and valve 240. usually,
The development and fixing time is about 3 seconds. Once the microprocessor 302 has provided sufficient time to develop and fix the film, the microprocessor 302 again turns on the pump 25.
2 and valve 238 are operated to clean the monobath from the developing chamber 210 and rinse the film with water. Then,
Microprocessor 302 processes pump 252 and valve 2.
Stop operation with 38.

The hologram thus created is rotated using the handle 78 to rotate the mirror 68 counterclockwise as viewed from FIG. The shutter solenoid 102 can be activated and observed by closing the switch 400. If desired, a camera may be pointed at plate 136 to take a picture of the hologram at this stage. For this purpose,
Instant cameras such as those made by Polaroid and Eastman Kodak are useful.

When it is desired to create the next hologram, switch 384 in microprocessor 302 is closed, allowing the microprocessor to activate pump 292, which connects conduit 218 and tubing 292.
All the liquid is pumped out from the developing chamber 210 through the tube 266 and discharged into the discharge tank 268 through the pipe 266. During this operation, the check valve 234, the ventilation pipe 23
2, and air enters the developing chamber 21 through the piping 230.
0. The device is ready to start a new operating cycle, and momentary switch 3 is activated.
04 is closed and the film 184 is sent. The purging process, which is performed by closing switch 301, is performed only once at the start of the test operation, and is not required any more when the test is being repeated.

The apparatus of the present invention can be used for immediate holography by simply developing the film 184 after a single exposure and viewing it with a laser beam reflected from a stressed pipe.

The device described above can be used without a housing to block the light beam when used in a room that can be darkened. If the device is used outdoors, a housing 81 is required to block the light beam. Housing 81 has an integral portion 396 with an open bottom on the side opposite photographic station 86. When used, the housing 81 is fixed to the frame 4,
Trough 40 tightened by screws indicated at 402
1 is accepted. The shiny part 404 is the side black cloth 4
06,408 and end black cloth 410 and 412. The black cloths 402, 408, 410, and 4
12 is adhered at its upper end to an integral part 396 of housing 81. As shown in FIG. 14, the black side cloths 406 and 408 wrap around the pipes 12 and 84 and the coupling ring 82.
They are held together by adhesive tape strips indicated at 414. End black cloths 410 and 412 are wrapped over pipes 84 and 12, respectively, and black cloth 40
6 and 408 to prevent light rays from entering from the ends of the light section. Such blanks and lights are common as seen in US Pat. No. 1,171,914.

The housing 81 has a light-tight cover 420 pivotally attached to the housing 81 at 422 and covering the opening 424.
and the cover, when opened, allows the photo station to be seen. A handle 428 is attached to housing 81 to facilitate transport of the device.

As mentioned above, the shape of the periphery of the developer chamber is such that it constantly changes direction by an angle of more than 125 degrees, thus making many different shapes possible.

In FIG. 15, supply conduit 214A and discharge conduit 2
16A is the same as plate 120, but with oval groove 12 including gasket 126A.
An alternative transparent plate 120A having 4A is shown.

An alternative transparent plate 120B (FIG. 16) is identical to plate 120 in that it has a supply conduit 214B and a discharge conduit 218B, but has a decagonal groove 124B and a gasket 126B therein.

An alternative transparent plate 120C (FIG. 17) has the same supply conduits 214C and exhaust conduits 218C as plate 120, but its grooves 124C have straight sides 450 and 452 and curved portions 454 and 45.
6. Gasket 126C is groove 124C
It's in.

It will be appreciated that plates 120A, 120B, and 120C and their associated grooves all form a development chamber with a suitably shaped peripheral plate 136.

[Brief explanation of drawings]

1 is a front view of a hologram device according to the invention without a housing; FIG. 2 is a right side view of the device shown in FIG. 1 without a housing; FIG. 3 is a view of the device shown in FIG. 1 without a housing. A plan view; FIG. 4 is a drawing showing an example of the use of a fixed saddle; FIG. 5 is a drawing showing an example of using a fixed saddle; FIG. 6 is a left side view of the device shown in FIG. 1 without a housing; Figure 7 is an enlarged plan view of the photo station; Figure 8 is an enlarged plan view of the photo station;
9 is a diagram of the hydraulic system of the device shown in FIG. 1; FIG. 10 is a diagram of the microprocessor and related elements of the device shown in FIG. FIG. 11 is a front view of the apparatus shown in FIG. 1 with the housing in place; FIG. 12 is a top view of the apparatus shown in FIG. 11; FIG. 13 is a front view of the apparatus shown in FIG. Cross-sectional view seen from the plane shown; 1st
FIG. 4 is a partially cutaway cross-sectional view taken from the plane taken along line 14--14 in FIG. 11; FIG. 15 is a plan view of an alternative transparent plate and gasket; FIG. 16 is a plan view of an alternative transparent plate and gasket; Plan view of gasket; FIG. 17 is a plan view of an alternative transparent plate and gasket. In the figure, 2: hologram device, 4: frame, 8: saddle, 10: pipe support arc portion, 1
2, 84: pipe, 26: strap, 60: laser device, 62: power supply, 64, 68, 90: mirror, 81: housing, 86: photo station, 94: shutter, 102: solenoid, 21
0: Developing chamber, 120, 136: Transparent plate, 1
24: groove, 126: gasket, 184: film, 214: supply conduit, 218: discharge conduit, 30
2: Microprocessor.

Claims (1)

[Scope of Claims] 1. A first transparent plate having an annular gasket arranged in a raised manner on its surface; a second transparent plate for sandwiching a photographic film with the emulsion coated side thereof facing the first transparent plate; and a moving means for relatively approaching and separating the first and second transparent plates. a feeding means for feeding the photographic film while the first and second transparent plates are separated; and a developer and cleaning water in a developing chamber surrounded by the first transparent plate, the gasket, and the photographic film. a discharge passage for discharging the fluid in the developing chamber; and a photosensitive device for irradiating a laser beam onto an object to be inspected and irradiating the reflected light onto the photographic film in the developing chamber through the first transparent plate. A hologram apparatus comprising: a laser beam irradiation means; and an observing laser beam irradiation means for irradiating a laser beam that passes through the first transparent plate, the developed photographic film, and the second transparent plate. 2. The hologram device according to claim 1, wherein the gap between the first transparent plate and the photographic film is between about 0.127 mm (0.005 inch) and about 2.032 mm (0.080 inch). 3. The hologram device according to claim 1, wherein the gap between the first transparent plate and the photographic film is about 0.127 mm (0.005 inch) to about 3.175 mm (0.125 inch).