anatomy of a webcam

[huzefasi]

I need some help with understanding how a webcam works. I opened up my logitech webcam and I see lens, sensor and a circuit. I am particularly interested in the nature of this circuit. My understanding is that the digital data stream from ADC is passed to the computer directly ie there is no DSP such as in a "real" camera. All the processing is done by the computer CPU. Am i right?

Any idea what the green circuit board is doing?

Thanks in advance for your help.

 

[blueroomelectronics]

Google is handy.
HowStuffWorks "How Webcams Work"

 

[huzefasi]

thats not exactly what I am looking for.

 

[blueroomelectronics]

What exactly are you looking for? The IC inside the webcam is quite complex, take a look at the old video capture cards for a PC circa 1990 and you'll get an idea how complex.

 

[huzefasi]

My understanding is that the digital data stream from ADC is passed to the computer directly ie there is no DSP such as in a "real" camera. All the processing is done by the computer CPU. Am i right?

For start can you confirm this?

Secondly I am curious if a webcam [remote camera] with high quality point and shoot size lens/sensor can be made without DSP/LCD/buttons such that the processing/control is done via computer? In such case what kind of IC is necessary?

 

[blueroomelectronics]

Philips makes some ICs with video decoders. Are you trying to build a webcam? What do you want to connect it to?

 

[huzefasi]

I want to make high end camera based on micro four thirds format which is especially designed to be used with a laptop. I figure all I need is a sensor and basic circuit and the rest of operations such live view, storage, processing, power supply can be done via laptop. I can use interchangeable lens which can be bought from olympus/panasonic.

Any advice?

 

[birdman0_o]

Are you going to write the software for your laptop?

 

[huzefasi]

Another thing I am not sure about is how to implement contrast based passive autofocus. afaik this doesnt require a separate sensor and is actually implemented in the software.

 

[huzefasi]

Can I use software or code for laptops's built in camera for processing?

 

[blueroomelectronics]

Where are you going to buy the 4/3 sensor? You're going to find it cheaper to buy a digital 4/3 camera than build one.

 

[huzefasi]

I was thinking of contacting Olympus and panasonic for sensors.

Four Thirds | Contact

To Manufacturers considering developing or selling the Four Thirds compliance product.
For inquiries on Four Thirds System standard, please contact the following E-mail address.
four-thirds@ot.olympus.co.jp.

Panasonic GH1 with the Lumix G VARIO HD 14-140mm/F4.0-5.8 ASPH/O.I.S. lens will costs $1500. I dont think it building one, IF it is possible, will cost me that much. I think it will be fun experience plus I am unemployed at the moment.

you guys haven answered my single question. any suggestion for a more appropriate forum?

 

[blueroomelectronics]

Seriously just buy one, you can't build one.

 

[huzefasi]

pls explain why I can not build one. That will help me decide whether to spend my time finding a solution or go backpacking.

 

[blueroomelectronics]

What's the most complex electronic device you've even built?

 

[huzefasi]

I am currently doing my major in Maths. Honestly I dont have much of electronics background but I enjoy science.

Ok so what do I need to know? I enjoy self study and I can get some texts if you can help me out with where to start.

I imagine the most complicated thing to be auto focus - controlling the lens via software based contrast measurement. I am not going to build complicated hardware or write software. Digital data from ADC will be processed by the laptop just like webcam. I will just have to find a way to use many existing webcam software with my camera.

 

[blueroomelectronics]

Go backpacking. Get some fresh air. It's a really really complex project.

 

[Krumlink]

I am currently doing my major in Maths. Honestly I dont have much of electronics background but I enjoy science.

Ok so what do I need to know? I enjoy self study and I can get some texts if you can help me out with where to start.

I imagine the most complicated thing to be auto focus - controlling the lens via software based contrast measurement. I am not going to build complicated hardware or write software. Digital data from ADC will be processed by the laptop just like webcam. I will just have to find a way to use many existing webcam software with my camera.

Come back when you have an bachelors in EE at least before you attempt this. Why not buy one? They are about 20 bucks.

 

[blueroomelectronics]

Not when you want to build a DIY one of these.
**broken link removed**

 

[huzefasi]

I dont mind paying someone who is interested and ready to help me out. whom should I look for? electrical engineering? what year?

My project is not as complicated as building an actual camera. I dont need to make lens, CPU, interface, lcd, battery, memory... It will be controlled completely by laptop software.

Important things I need are sensor!, powerful autofocus motor, gyrosensor for image stabilizing and hardware to send the digital signal to laptop via USB 2.0 port.

I dont mean to imply that it is easy, I know it is very complex but I am not convinced DIY is impossible, particularly when I can seek help.