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Cable length of MIPI camera is always an issue in real application. Herewith, we want to share some experience with customer. First of all, we need to understand a bit of MIPI standard, we attach at the end of this essay some info which is abstracted from some technical articles, for information. From our expereice, impedance of cable is important, shielding of twist pair cable is also important. I do believe people knows PCB layout for these signal path is critical but people may not know the shorter the openings…

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C8203 and C8209 are two main back end module to interface micro cameras from COMedia. C8203 has been designed to output HDMI signal and connect to HD monitor for video display. C8209 is for PC connection thru USB port. They are able to connect different sensor and LED configuration, therefore we have assigned different part number for it. Below is a detail list. C8203D/M/H C8209D/M/H For D suffix， there is a chip OV426 on the board. For H suffix, there is a chip OV428 on the board. For M suffix,…

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C8262 and C8209 are the backend module to interface muC103 (OVM6946) and connect to PC thru USB port for video display. C8262 is our 1st generation USB VPU and C8209 is our 2nd generation VPU. Here is the difference between the 2 modules. LED C8262 does not provide LED control circuit, users need to build their own LED circuits. C8209 board has been integrated with LED control circuit. C8209DP support up to 300mA current for external LED use, C8209DL and C8209ML support small LED on the camera tip. USB Connector…

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The Extension Unit is a method provided by the UVC specification to add vendor-specific building blocks to the specification.The USB Video Class specification defines a mechanism to extend the functionality of devices that comply with that specification and describes the behavior of Extension Units. Independent hardware vendors (IHVs) can enhance the value of their devices by adding functionality that goes beyond that described in the specification. This extension mechanism requires operating system support and some user-mode plug-ins so that applications can work with these extensions. The USB Video Class driver architecture provides…

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Both OV426 and OAH0428 are used in our back end modules. The OV426 is a single chip solution for small medical image sensors like the OV6946 and OV6948. The OV426 provides an integrated analog-to-digital data conversion using a built-in A/D converter (ADC), black level calibration (BLC), AEC/AGC and a final digital video parallel output (DVP). The OV426 supports a standard SCCB interface to communicate with the system and manipulate the above mentioned functions. OAH0428 is a single companion chip solution that provides an integrated analog to digital conversion and limited ISP functionality including…

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We have developed a series of camera modules based on OVM6946, OVM6948, OCHTA10, OCFHFA10 and other sensors, some models with P, some models with L, and some with numbers, here below to explain the meaning of these suffixes. T: This is the earliest model, only for muC103. muC103T is based on OVM6946, no LED installed at the tip and the connector is a 1.25mm pitch 6pin holder. P: It is camera only, not come with LED for illumination. It is good for those customers want to use optical fiber as…

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COMedia has been in the camera module industry for over 30 years. We have developed a range of products to meet various applications. In adition to the standard modules, we provide custom design to meet the special needs of customers. For medical system, we help people in customization of camera module as well as the back end processing board. For Camera Modules Steel sleeve – We can provide either or not the steel sleeve for camera. The steel sleeve can be in different lengths. In order to minimize the OD…

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Vertical line in the camera system of OVM6946 is commonly happened in most of the product. We would like to share some experience in resolving this issue. OVM6946 is a 1/18″ color CMOS analog 160 Kpixel (400 x 400 ) camera module with lens. When a long extension cable is used, a vertical noise pattern is often found in the image, as shown in the below figure. The OVM6946 has 4PINs connecting to the OV426 decoder chip, which are AVDD, AGND, XVCLK VOUT. Clock input (4MHz)Cable (50 Ohm impedance)Vout signal…

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OmniVision has quite a few of small footprint camera cube, which is good for medical application. They have aslo changed their model number system for the new parts. Some customers may not familiar with these number. We would like to explain this as below for better understanding. OVM6946 and OVM6948 are the first generation of small camera modules. OCHTA10 and OCHFA10 are the second generation of small camera modules. Camera size OVM6946 1.05 x 1.05 mm OVM6948 0.65 x 0.65 mm OCHTA10 0.65 x 0.65 mm OCHFA10 1.05 x 1.05…

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OmniVision recently announced the OCHFA10, OCHTA10 and OAH0428 bridge chips with CameraCubeChip® technology for endoscopes and catheters.Special features of the OAH0428 companion chip include HDR, auto-start, pseudo-global shutter, increased NIR sensitivity and various safety features. This chip is also autoclavable. The OAH0428 has a proprietary 4-pin digital interface for up to 4 meters. Exposure time and gain settings can be sent from an external SPI controller, automatically by the OAH0428’s internal AEC/AGC or manually via the host computer. We do believe this bridge chip has powerful functions but for us,…

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Some customer asked why COMedia need to make his own sensor module with cable while OVT provided cable assembled sensor module. Nowadays, direct soldering wire to sensor ball grid is not an issue, many manufacturers can handle manually or semi-automatically. We don’t understand why OVT insisted to provide cable assembled module than sensor alone. In fact, cable itself is more important than soldering technique. First of all, cable characteristics is critical, it should be right impedance and well insulated, to prevent from interference to each other. Secondly, length of cable…

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After few years waiting, we saw the chip at last. It is has 400×400 resolution but the size is same as OVM6948. OVT treats it is an upgrade of OVM6948, quadruples the resolution and keep the size. We treat it an upgrade of OVM6946, the same resolution but smaller size. The most important is, it is compatible to OVM6946 in register setting. Means, we can direct replace OVM6946 and plug in to the backend modules, no need firmware changes. Here is what OVT describe the chip. OMNIVISION’s OVMed® OCHTA camera…

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