Designing a laser based portable projector

Reflections (1)

2009-08-20T22:13:00.000-07:00

We have learnt that many people work in many different ways. Only if we accept compromises can we make progress. But if one loses hope of completing a task, then the group would suffer entirely. Hence, it is crucial to stay focused and optimistic as a team. What we want to emphasise is that we have learnt a lot of teamwork, we understand the weaknesses of each of us and we work together to cover up for each other. This ensures that we complete our tasks on time and not impede the progress of the project.

Of course, we have learnt many new skills in the process. Lab practical skills in the field of engineering were an eye-opener to the few of us when we got to explore and learn more through hands-on, even if we make a big accident. Skills such as welding, attaching digital circuit components, using a spanner or wheel and axle efficiently are not skills you can learn in the school's science labs. Such practical skills require you to step out of your comfort zone, find someone you are truly able to work with and then hone your skills as both an individual and as a group. Such a project definitely expands our horizons, lets us learn whether we are truly interested in something and most importantly, it tests our determination. We even had to work till 9 p.m. on some days to settle our reports and also our labwork. When one screw fails, we try another screw and if it fails, we try another till it succeeds.

Finally, we have of course met new people, like our dearest mentors and got to understand them even better. This project also enables us to work in an industrial lab with so many new tools, milling machines, large knives for cutting metals etc. We can then learn more and understand more about these tools and I am sure we can put this knowledge to good use in the future.

We would like to thank our three dearest mentors who have helped us a lot and of course, the various lab technicians who have helped us in one way or another. This project will not stop here, we will keep on simplifying it till it looks small and yet magnificent.

2009-08-17T21:43:00.001-07:00

Meeting started at 2:45 p.m. at Ngee Ann Polytechnic

Half of the projector has been completed. The heavy base for added stability is now in place and the rotating mirror is ready and working. It spins at a high speed to generate a centralised image in the middle of the vortex while the laser beam is dispersed into a 360 degrees arc in the surroundings, creating a visual impact.

Meanwhile, we added 2 more screws onto the base of the rotating volumetric screen for added security. It ensures that the screen will remain tightly attached onto the heavy metal base and will not start moving when the screen spins, which can be extremely dangerous and hazardous to onlookers.

Next, we decided the arrangement of our circuit components, ranging from our Compact Visual System, our Digital Signal Processor, our laser power supply and the laser controller. We placed these components in their approximate positions and stuck masking tape on these areas so that the lab technicians knew where to drill a hole into the heavy metal base. We intend to connect our electrical and digital components by Thursday.

Finally, we placed an order for a perspex box, which would allow us to see through into the image, but it ensures added security as well because should the volumetric screen fly off its support while rotating at a high speed, the perspex, being a tough material, would weaken the impact and lower the speed of the screen so as to minimise damage and hurt.

Meeting ended at 6:00 p.m.

2009-08-03T20:22:00.000-07:00

Today, we had finally conceptualised our third prototype, and the main motivation is to make it even more portable for the purpose of convenience. Since the second prototype was extremely bulky and hard to be carried around, the third prototype could settle this problem easily. The main working principle behind our third prototype is that it can be detached into three separate portions: a heavy metal base for stability, a long perspex vertical column, and a top box consisting of the optical components. These three components can be brought around separately and then reassembled at the presentation venue.

The next step is to disassemble our second prototype which was what we did. We retained all useful components like the crossbars and golden rods, but disposed of faulty equipment like rusty and loosened screws. Every single optical component was also removed and placed onto the working bench separately.

We then placed orders for a motor of higher power so that it can rotate more quickly and generate a higher resolution image and also for a 3.0 metre long perspex cylinder with one covered end for our supporting column.

Mr Lee agreed to help with the welding and milling portions, but we are to do the optical arrangement by ourselves.

Meeting ended at 5:30 p.m.

2009-07-20T21:51:00.000-07:00

Meeting started at 2:30 p.m. at Ngee Ann Polytechnic, Centre of Innovation.

Today's meeting was mainly about discussion. After hearing the judges' comments that our projector needs to be more portable, we brainstormed on any ways we could make it smaller or easier to carry around without compromising on other qualities.

Currently, our laser projector looks big because of the optical table and the supporting metal frames. We discussed if we could do without the frames but they were needed to hold the projector in that position above the screen. Kiat Long suggested that the big frames could be made foldable to be kept at the side of the projector like the handle of an umbrella but Mr Lee disagreed because fixing a single hinge joint can cost a lot. He disagreed with us dismantling the setup and assembling it at the judging venue because we might make a mistake out of nervousness or stage fright.

Mr Lee strongly insists that we fix everything such that the bigger optical table would have a large square gap in the middle. The smaller optical table would carry the volumetric screen while the larger table carries the metal supporting frames. The smaller table can be pushed under the table and erected upwards for the image to be formed on the screen. The height of the screen relative to the ground will also be adjustable.

The Centre of Innovation also plans to purchase and machine the flimsy metal frames to be much thiiner and yet sturdier. kiat Long suggested bamboo poles, but that would look extremely unprofessional on a mechanics physics tool like a projector. Bamboo is also hollow and will weakness the overall support of the projector itself. We also discussed changing the values in the terms of the lens equation to reducethe distance and will aloow us to scale down the projector, but this would require a new DMD, Laser Source and lenses. In terms of price and effort needed to purchase these materials, it is not worth it.

We then went on to discuss our presentation. mr Lee helped us brainstorm certain questions like the judges may ask. Mr Lee thinks that there is nothing wrong in making the projector bulkier if it can display impressive 3D images during satellite communications or for wide-screen cinematics. This is more of an R&D Project than an Innovations one and it will not be possible to tell whether it will be a success or failure at such an early stage. Finally, Mr Lee expressed worries regarding the lack of time and funding and also regarding the programming software portion of our project. We attempted to learn about mathematical formulae such as Fourier's Plan to help with developing source codes, but were still rather unclear after that.

Meeting ended at 4:45 p.m.

2009-07-06T00:21:00.000-07:00

Meeting started at 0900h at Centre of Innovation

Today, we did a test run of the newly designed projector. After reconnecting the power supply and the laser software, the projector could function properly. However, the image of the rotating head was rather blurred since we were not using a high quality laser and the distance between the laser and screen is large, so there is large energy loss. Also, the ceramic tile, is the screen is rather thick, thus there is a large distance for diffraction of light rays to take place.

Next, we increased the image distance, so as to magnify the image. This was done by moving the laser frame upwards by approximately 8 cm. However, we decided to change to a newer table so as not to compromise with the quality of our image. Also, we are removing one of the leg barriers of the optical table so as to open up a space to insert a smaller table carrying the screen.

To improve the quality of the image, we decided to rectify the source, such as to make one frame per degree; as such, we created 360 images for one complete 360 degrees rotation. These images will then be inputted into the Compact Vision System. With a quantization of images, there would be smoother transition of the displayed image and would thus be of a higher quality. After which, we modified the Labview source cdes further, creating one which could process and transfer the 360 head rotation images.

Meeting ended at 1230h

Procedure for transferring images into the Compact Vision System

2009-07-01T21:13:00.000-07:00

Meeting started at 2:15 p.m.. Our agenda for today is to practise and be sure of the transferring process.

1) Log in as Administrator Account

2) Go to National Instruments, Measurement and Automation Explorer

3) Click on remote devices and select CVS, then right click and select file transfer.

4) Delete all files in the remote directory and create a new folder with a suitable name,

5) Transfer all images into the folder in numerical sequence

6) Open up the project file with Labview, and ensure that the images are in the corresponding format (.bmp / . jpg ) as according to the source code and Labview programme

7) Next, after ensuring the source code's correct, go to Project's Tab and create a new project

8) Go to my Real-time applications, right click and select build all, then build again, deploy and finally run as startup.

9) Finally, reboot the Compact Vision System so that the image can be reloaded.

Meeting ended at 5:30 p.m.

2009-06-08T15:04:00.000-07:00

Meeting started at 8:55 a.m. at Ngee Ann Polytechnic

Mr Lee started off by explaining to us the shortcomings of our previous design, such as being too compact and yet the outer casing was bulky etc. Mr Lee then introduced to us new concepts which led to newer designs for the laser projector. We then went to Research Lab 1 to determine which material would be most suitable for a image display surface. After numerous experiments involving laser diodes, we concluded that white paper and cement were equally good.

Kenneth was then tasked to read Joseph W. Goodman's Book "Introduction to Fourier Optics" pages 137-160. It contained information about frequency response for diffraction-limited incoherent imaging, optical transfer function, aberrations and their effects on frequency response, comparison of coherent and incoherent imaging.

Kiat Long then searched the catalogue for the laser power supply. Jonathan was observing Mr Lee's work on machinery, offering valuable advice. He was using the milling machine to smoothen a metal block, removing the layer of rust over it. However, the block had to be coated with a layer of silver polish to make it look more appealing to the audience. Also, we all went through the project proposal, Mr Lee pointed out to us the places which required more elaboration, such as the rationale for our project and our methodology.

Meeting ended at 12:45 p.m.

2009-05-25T20:54:00.000-07:00

Meeting started at 2:30 p.m. at Ngee Ann Polytechnic.

We had to test out the transferring of images into the projector's hard drive once again. This is because the transfer cable has just been replaced and we need to ensure it can function optimally. We transferred Jonathan's images of a rotating cup as a sample because the image was the least complicated and had the smallest file size. The image transfer had proceeded rather smoothly until the last 10 images, which could not be transferred because the maximum storage capacity of the projector's hard drive had been reached. The three of us were consideing whether to replace the storage drive of the projector with one of larger file size.

Next, we observed a welding process. Screws are permanently attached to a metal block via the solidified welding liquid. A pointer placed in an immersion heater of 400 degree Celsius was used to pick up welding liquid which was then applied onto the screw. About 2 minutes later, the screw was permanently fixed to that region. Mr Lee then did the same to the other screws on a perspex plate so as to fit the plate in place.

Kiat Long was then given a book on diffraction optics to read. It considered the main theories of diffraction and interferenc, such as Ferauver's theorem. These information were then incorporated into the project proposal and report. Mr Lee also told us how we can improve our proposal by mentioning more about diffraction optics. Not too much emphasis should be placed on the application of lasers because it might cause the readers to lose track of direction.

Meeting ended at 5:30 p.m.

2009-05-18T20:48:00.000-07:00

Meeting started at 2:45 p.m. at Ngee Ann Polytechnic

We discussed the display screen and it was pointed out that a screen using mist was not very good because it is extremely bulky and hard to transport around. Furthermore, the cost of the screen is exhorbitant. We are thus consideing an alternative method.

Also, we figured out that 1 of the laser power supply had been damaged, either due to wear-and-tear or a short circuit. As such, the laser power supply would have to be replaced ASAP or the laser cannot function. Next, we also watched the machining portion, Mr Lee kindly demonstrated to us how two different parts are attached together, either by screws or by liquid gels which solidify after a while. We also had to take out the upper cover of our projector prototype so as to remove the damaged power supply.

Lastly, we checked our 3D MAX images stored in the C;/ drive of the main 3D computer of the campus. The images were still intact and in proper sequence.

Meeting ended by 5 p.m.

2009-05-11T16:43:00.000-07:00

Meeting started at 9 a.m.

We called up the supplier for the projector plug and instructed them to deliver the plug by today if possible. This is to ensure further developments of our work can proceed on. The two boxes containing the mechanical components can then be attached together.

Next, using 3D MAX software, the three of us worked on our images to be inputted into the CGH. Jonathan drew a rotating mug, Kiat Long drew a rotating car tyre while Kenneth drew a rotating truck. We then rendered our images for each of the 100 frame images, thus producing 100 Bitmap images for each form. These images can then be inputted into the CGH Hologram via a Labview source code when they are ready.

Meeting ended at 1:30 p.m.

2009-04-20T20:33:00.000-07:00

Meeting started at 2:30 p.m. at Ngee Ann Polytechnic.

We added an outer covering to the box, covering 4 sides. The laser driver is now ready to be installed as well. Screws were also added onto the box so as to enhance the security of the set-up.

We also decided to work on improving our humidifier, to create one better than the conventional one. A non-conducting perspex plate should also be placed underneath the DMD so as to prevent electrocution and to provide extra support to the circuit components. We commenced working on the images to be inputted into our projector as well. Paint software is to be used to make the design simple and yet elegant.

Lastly, we started to source for a laser supplier and are ready to have our laser ready within one month.

2009-04-13T20:21:00.000-07:00

Meeting started at 3 p.m. at Ngee Ann Polytechnic.

Our first box is mostly completed, holes had been drilled and the relevant components such as the digital micromirror device, laser drivers, compact vision system, power source and beam splitter have been installed and placed in the appropriate positions. The box looks different in real than on paper, in fact, the design had been modified quite a bit. What's left is to cover the box after wiring it up and to add the necessary lenses and mirrors.

Next, we discussed the supplier for a laser source. We decided on a 1 - 2 Watt laser supply, ensuring its theoretical volume can fit into our boxes. We need to find the wavelength of a green/orange laser that is marked TEN000 and me-he. Mr Lee has provided a list of suppliers which can be called up. Next, we need to use Paint programme to design some images to screen, because it would be impossible to use an image projector without images. We also explored the Labview software to get ready for our next procedure, the software component. We also need to buy BGA port cables from any hardware, electronice or DIY shop, they must be 1 male and 3 female plugs.

We shared the progress of our project with the deans of Ngee Ann Polytechnic afterwards, with a brief Q and A session.

2009-04-06T06:20:00.000-07:00

Meeting started at 2:30 p.m. at Ngee Ann Poly

Today, we redesigned the interiors of our laser projector mechanism. The outer design had already been settled, now we did some minor shifting of our interior designs so as to fit in more components. The rationale for this is to save space and make it look aesthetically nicer.

Here's the revamped interior of our bottom box :

Here's the front view of the same revamped box :

Below this sentence are all the separate components necessary for a successful projector :

1) DMD ( Digital Micro-mirror Device )

2) Laser Drivers X2

3) Compact Vision System

4) Laser observer

Meeting ended at 5 p.m.

2009-03-30T06:37:00.001-07:00

Meeting started at 2:30 p.m. in Ngee Ann Poly

We decided to modify our laser projector set-up once and for all, due to the polarizations of the laser beam, thus a different design had to be conceptualized. A handle was added into the blueprint as well.

We were to design a plug to accommodate 4 other plugs and also to source for 2 beam expanders and a 500 mW green laser with the cheapest price and cheking the polarizing directions at the same time.

Meeting ended at 5:30 p.m.

2009-03-23T21:22:00.000-07:00

Meeting started at 2:15 p.m. at Ngee Ann Polytechnic

Timeline is to be drafted for our project so as to have something as the basis to judge the progress of our project.

Various suggestions for design of projector : DMD is to be placed in 1 box, together with the 2 laser controllers if possible to make use of space.

Project is also to be divided into 2 portions : CGH portion and the Optics Portion

CGH portion : Developing the codes for a 2D CGH so as to be downloaded in SLM to produce an image. Labview software can be used to alter the image. A reference wave is added to the object wave from the object itself to form a hologram known as the CGH, requiring knowledge of the diffraction and interference theories. Source codes must also be improved on and the parameters must be changed so as to improve the quality of the image formed. Magnification can also be altered by shifting tbe position of the lenses to alter the image distance and object distance as well.

Optics portion L Ensuring optimization of the images formed and a beam expander, a combination of the objective and convex lens can be used to transmit the laser beam into 2 different beams. Laser power and lens equation decides the display area of the image, so to display one with a larger area, a higher powered laser could be made use of.

Meeting ended at 6:15 p.m.

2009-03-16T16:12:00.000-07:00

Ngee Ann Polytechnic, 8:45 a.m.

Prepartions for the projector dismantling operation were ready, all the necessary devices have been prepared, such as screwdrivers etc. Cross cables are to be used to download the image to the projector using Labview software. The National Instruments Measurement and Automation Explorer software was used to create a link from Labview to the projector.

The CVS IP address is : 192.168.10.10 As such, the PC options must also be reconfigured to the same IP address to establish the link.

In order to change the image :

Use the right mouse click on CVS in MAX and select the file transfer option, images can then be uploaded into the projector using this option. However, all files in the remote directory must be deleted prior to the transfer itself. Next, going back to Labview, under Project Explorer, go to my real-time images/ applications. Then under building applications, selct build all, build again, then display and run as start.

Next, we dismantled all the components of a conventional light based projector. Here is how the original projector looked like with most of its components intact:

Here are the components after dismantling :

Laser Drivers :

Meeting ended at 1:30 p.m

2009-03-09T19:45:00.000-07:00

Meeting started at 2:00 p.m. at Ngee Ann Polytechnic

More practice was to be placed on the Labview programme. Mr Lee told us that we are not just going to focus on labview, but also to dismantle a projector and take down the dimensions and lastly coming out with a diagram of our prototype if time permits.

Firstly, we practised Labview, starting with the design of a Shift Register circuit, which was highly successful, just on the first try. We also made use of the Elasped time function so that the program does not execute too quickly and is only executed in a set period of time. A pink wire attached to the elasped time symbol refers to a STRING. We also made use of While Loops and the Compare Function; once the output reaches a certain value, it will automatically reset to the original.

Next, we decided on how we should modify the projector to be used as the product of the experiments. Tasks :

1 ) Design blueprint of the prototype
2 ) List down all required appratus needed, with specifications if possible
3 ) Calculations for focal length etc. using the lens equation to ensure proper positioning of the lenses.

Our original design was to put everything in a rectangular box measuring 45 cm X 20 cm X 16 cm. However, we decided that this was far too original and uncreative and was too bulky as well, and soon rejected it. We left the designing stage to the next session.

This is an image produced by that of a conventional image projector :

Meeting ended at 5:20 p.m

2009-03-02T17:49:00.000-08:00

Meeting started at 2:30 p.m Ngee Ann Polytechnic

Today, we were introduced to the basic concepts of Labview, at the same time being given a basic demonstration of one of the exercises before letting us try out the program.

At the start, we were very confused about how to use the program as we found it to be very complicated, like an advanced form of C ++ ... After more explanations by our mentor and spending some time familiarizing ourselves with the software, we finally managed to come out with our first diagram successfully.

Although there were some problems with our diagram, we gained a lot of valuable knowledge about the software although we were still rather complicated by it. We resolved to familiarize and understand the software by June.

We also agreed to incorporate a humidifier as our screen into our laser projector. This is to allow a 3D image to be projected, which is unable to be shown on a plane screen.

Meeting ended at 4:30 p.m.

Group Discusiion 1

2009-02-15T20:57:00.000-08:00

Ngee Ann Polytechnic, 2:35 p.m.

Started discussing the administrative details of our project, at the same time viewing a setup of a projector displaying a 3-dimensional hologram using the mist from the humidifier as a screen.

We would be modifying a conventional projector, changing and rearraging its components so as to create a smaller and portable one. At the same time, we would be changing the parameter of the Labview codes so as to enable a better quality image to form.

We learnt today that laser projectors are much more effective than conventional projectors which work on white light and smaller versions of these projectors would have further applications in the future market. 3D images, if can be displayed would also be more appealing to members of society although projectors producing these high quality images are still in the design stage.

If there is sufficient time, we would design a mist to be used as the screen for the image to be displayed on.

Ngee Ann Polytechnic, 2:35 p.m.

2009-01-21T16:50:00.000-08:00

So, we have chosen this innovation project, that is to design a portable laser based projector. Our objectives are very, very clear :

1 ) To design a projector from scrap materials
2 ) To make a projector that is light and portable
3 ) To make a projector that can produce a clear and sufficiently large image.

This is the standard overview of our project