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Summary of content (32 pages)

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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Table of Contents Introduction to camera module troubleshooting................................................................................................................1–5 The effect of image taking conditions on image quality...................................................................................................1–6 Image quality analysis ............................................................................................
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 17 Shaken image.............................................................................................................................................................1–26 Figure 18 Camera white balance failure and overexposure...........................................................................................1–27 Figure 19 Color difference between flash colour limit samples.......................................................
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Introduction to camera module troubleshooting Background, tools and terminology Faults or complaints in camera operation can be roughly categorised into three subgroups: 1 Camera is not functional at all; no image can be taken. 2 Images can be taken but there is nothing recognizable in them. 3 Images can be taken and they are recognizable but for some reason the quality of images is seriously degraded.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Sharpness Good quality images are 'sharp' or 'crisp', meaning that image details are well visible in the picture. However, certain issues, such as non-idealities in optics, cause image blurring, making objects in picture to appear 'soft'. Each camera type typically has its own level of performance.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 2 Blurring caused by shaking hands Movement in bright light If an image is taken of moving objects or if the device is used in a moving vehicle, object 'skewing' or 'tilting' may occur. This phenomenon is fundamental to most CMOS camera types, and usually cannot be avoided. The movement of camera or object sometimes cause blurring indoors or in dim lighting conditions because of long exposure time.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 4 Noisy image taken in +70 degrees Celsius Phone display If the display contrast is set too dark, the image quality degrades: the images may be very dark depending on the setting. If the display contrast is set too bright, image contrast appears bad and "faint". This problem is solved by setting the display contrast correctly. This is normal behaviour; do not change the camera module.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 6 Flicker in an image; object illuminated by strong fluorescent light Bright light outside of image view Especially the sun can cause clearly visible lens glare phenomenon and poor contrast in images. This happens because of undesired reflections inside the camera optics. Generally this kind of reflections are common in all optical systems. This is normal behaviour; do not change the camera module.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Examples of good quality images Figure 8 Good image taken indoors Figure 9 Good image taken outdoors Image quality analysis Testing for dust in camera module Context For detecting these kinds of problems, take an image of a uniform white surface and analyse it in full resolution. A good quality PC monitor is preferred for analysis. Search carefully, since finding these defects is not always easy.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care If a dust particle is lying on the infrared filter surface on either side, they are hard to locate because they are out of focus, and appear in the image as large, grayish and fading-edge 'blobs'. Sometimes they are invisible to the eye, and thus the user probably does not notice them at all. However, it is possible that a larger particle disturbs the user, causing need for service.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care 3 User has tried to take pictures in too dark conditions, and images are blurred due to handshake or movement. This is no cause to replace camera module. 4 There is dirt between the protection window and camera lens. 5 The protection window is defective. This can be either a manufacturing failure or caused by the user. The window should be changed. 6 The camera lens is misfocused because of a manufacturing error.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 11 Image taken with clean protection window Figure 12 Image taken with greasy protection window Image bit errors Bit errors are image defects caused by data transmission errors between the camera module and the phone baseband and/or errors inside the module. Usually bit errors can be easily detected in images, and they are best visible in full resolution images.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Note: Make sure that the phone has the latest software before continuing. Results The camera is working properly. Next action If there are still problems with the camera, see "Camera baseband hardware troubleshooting". Page 1–14 Company Confidential Copyright ©2005 Nokia. All Rights Reserved.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Bad camera image quality troubleshooting See Also • Camera hardware failure message troubleshooting (Page 1–13) Issue 1 Company Confidential Copyright ©2005 Nokia. All Rights Reserved.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care RM-84 front camera troubleshooting Front camera hardware failure message troubleshooting Page 1–18 Company Confidential Copyright ©2005 Nokia. All Rights Reserved.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Flash LED troubleshooting Introduction to flash LED troubleshooting A fault or complaint associated to LED flash operation can be roughly categorized into two subgroups: 1 Flash is not functional at all (no light output at all). 2 Images can be taken and they are recognizable but for some reason the quality of images is degraded.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 15 overexposed image Distance to the target (too far away): The power of the white LED flash is still very modest compared to xenon flash technology. Even with the full power, the maximum distance for an acceptable image quality is roughly 1.2m. If the distance is greater than 1.2m, the images will appear dark and the noise level increases. This is normal behaviour; do not change the flash module.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 16 Dark and noisy image Shaken (= blurred) images The traditional xenon flash has the advantage of stopping the movement. This is a result of an extremely short and intense light pulse, which makes it possible for a camera to use very short exposure time. Due to the weak output of the LED flash, the exposure time has to be actually increased in the viewfinder mode in total blackness, instead of shortening it.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 17 Shaken image Camera white balance failure and overexposure due to presence of ambient light Because the spectral output of the flash is known, the white balance and the exposure control of the camera work in optimal way with the flash in total blackness. This is why some of the pictures may fail, if there is some ambient light present when the image is taken.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 18 Camera white balance failure and overexposure Colour difference between different modules There is some variation in the spectrum of the flash, which derives from the manufacturing process of the white LEDs. Because of this variation, there may be some variation in the colour of the images as well. This is normal behaviour; do not change the flash module.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Figure 20 Mechanical construction of the flash LED module The flash LED module as a component is not a repairable part, i.e. components / parts in the module cannot be changed. Only cleaning dust from the lens is allowed; use clean compressed air.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Steps 1. Take an image with the flash and monitor at same time whether the LED module flashes. Results If the LED flashes normally, the overall functionality of the module is OK. Testing image colours with flash Context With the help of this test you can check if the image colours are normal when using the flash. Steps 1. Take an image of a target, which contains something white in total blackness from less than 1 m range.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Flash LED troubleshooting flowcharts Bad image quality when using flash LED Flash LED indicator mode troubleshooting For checking the indicator mode functionality, force the camera to record a video clip and monitor the flash led at the same time. The flash LED should work with very low brightness constantly during the video recording. Page 1–30 Company Confidential Copyright ©2005 Nokia. All Rights Reserved.
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RM-84/99 Camera Module Troubleshooting Nokia Customer Care Flash LED HW baseband troubleshooting If there are problems in the flash LED driver circuit, the testing procedure is complicated, because the driver circuit output cannot be reliably measured without the load (LED). Load (LED) is always disconnected from the output when the phone is disassembled. Issue 1 Company Confidential Copyright ©2005 Nokia. All Rights Reserved.