Endoscope Camera Module Guide: Matching Sensors to Sub-2 mm Optics

The distal tube is 2.0 mm. The sensor on the bench is a 1/9-inch OV9734. The objective in the tray is a 2.4 mm OD barrel that will not enter the sheath. That is the usual endoscope camera module miss: a 1 MP headline with no outer diameter, no sensor diagonal, and no sterilization path. Pairing starts at the millimetre of silicon and the millimetre of steel, not at a megapixel count.

This page is the buyer-advocate checklist for that bench. The five inputs in the machine vision lens selection guide still apply; here “format” is often 1/9-inch and “environment” is autoclave, oil, or IP. Requirements vary by device class and market — confirm current medical or NDT rules with the relevant authority, not with a lens datasheet.

Pair the Sensor to the Distal OD

An endoscope camera module is a sensor plus an objective plus a distal mechanical stack. The lens image circle must cover the sensor diagonal. The objective outer diameter must clear the tube, the LEDs, and the adhesive fillet. Either miss fails the build. Lensmind pairs named sensors — OV9734, OV2740, ES101 — to sub-2 mm objectives and 1/9-inch endoscope modules. That pairing is the RFQ, not “1 MP medical camera.”

The endoscope lens family is the catalog after those two millimetres are written down. A standing cover such as LMQX6101A is a distal optic, not a USB inspection toy.

OV9734, OV2740, and ES101: What to Write Down

Published OV9734 modules are typically 1280×720 on a 1/9-inch optical format (fractional-inch formats are vidicon-era labels, not millimetres), with pixel sizes in the 1.4–1.75 µm class depending on the board vendor. Image areas around 1.8 mm × 1.0 mm appear on those sheets. That diagonal is what the objective must cover. OV2740-class 1080p modules are often 1/6-inch; they need a larger circle and usually a larger distal OD. ES101 shows up on 720p/1000p miniature lists. Do not mix a 1/6-inch objective onto a 1/9-inch chip and call it a drop-in.

Write the exact sensor part number, the cover-glass stack, and the chief-ray angle if the vendor publishes one. Miniature CMOS chips are unforgiving of CRA mismatch: corners go dark or coloured. Ask for the module drawing, not a marketing photo.

Sub-2 mm Objectives Are an Envelope

Sub-2 mm is the glass diameter plus coating plus barrel, not a “less than 2 mm camera.” The tube ID must also hold illumination fibres or LEDs. A 1.8 mm objective in a 2.0 mm tube with four 0402 LEDs is a stacking problem. If the RFQ only says OD < 2 mm, the first sample will fight the light.

1 μm-class active alignment exists for units that demand it. At these diameters, a few micrometres of decenter is a field of view that is no longer round. That is a factory step, not a set-screw on an M12 holder.

Medical Versus Industrial RVI

Medical device optics may need biocompatible materials, hermetic packaging, and a sterilization method the OEM validates — autoclave, H2O2, or something else depending on the device and the market. Endoscope as a device class is not a lens SKU; the distal objective is. Lensmind does not claim ISO 13485, FDA, or CE on this site. The quality system on record is ISO 9001 certified in 2024. Registration and labeling obligations sit with the device maker. Confirm them with a regulatory specialist.

Industrial remote visual inspection cares about oil, vibration, IP67/IP68 when specified, and a working distance inside a bore. A consumer drain camera is the wrong spend. If the job is a gearbox or a turbine, write RVI, not “borescope for home use.”

FOV, Depth of Field, and Distal Light

Wide distal fields (often 80–160° in this class) are how you see a lumen without steering. They also distort. Measurement inside a bore is not a telecentric job. If you need millimetres, you need a different architecture. Depth of field on a 1 mm EFL objective is short; published modules often quote bands such as 5–50 mm or 10–100 mm. Match that band to the inspection distance, then size the LEDs so the near wall does not bloom.

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Sealing, Alignment, and What Is Not Claimed

Hangzhou assembly cells are Class 10,000 (ISO Class 7 equivalent), zoned for medical and harsh-environment builds. Hermetic packaging is in the process list. IP67 / IP68 duty is quoted when specified — it is not a default badge on every SKU. Fog after sterilization is usually a seal or a material stack, not “the coating.” Ask for the packaging method on the drawing.

Do not invent ISO 13485, IATF, CE, or FDA on a Lensmind quote. If your file needs those, the device maker owns the gap. The factory will support drawings under NDA and batch reports (MTF, distortion, BFL, DOF as agreed).

What We Check Before an Endoscope RFQ

• Sensor: OV9734 / OV2740 / ES101 or the exact CMOS, format, cover glass.
• Tube: inner diameter, wall, LED count, target distal OD.
• View: FOV, working distance band, direction (forward or side).
• Duty: medical sterilization path or industrial oil/IP. No assumed certificates.
• Volume: sample now, annual quantity later. 48-hour first pass, 60 working days prototype to mass production, 30 days repeats, 50/50 payment.

Worked Scene: 3.9 mm Tube, OV9734

Illustrative path: 1/9-inch OV9734, 3.9 mm steel sheath, four LEDs, 5–50 mm working distance, industrial pipe, IP67 requested. The objective must cover the ~2 mm-class diagonal and still leave ring space for LEDs. A sub-2 mm barrel is plausible. A 6 mm USB module is not. If the next revision is OV2740 1080p, the circle and the OD both grow — do not reuse the first barrel.

Company registered 2019. Founding-team practice is 26 years; that is not company age. Custom tooling is stored free for 5 years.

Conclusion

An endoscope camera module is a sensor-to-tube stack. Cover the chip, clear the OD, then talk FOV and sealing. Named sensors (OV9734, OV2740, ES101) and sub-2 mm objectives are the pairing language. ISO 9001 is the plant badge. Medical market access is the OEM’s file.

Key takeaways

• Write sensor + format + distal OD. “1 MP” is not a spec.
• OV9734 is commonly 1/9-inch 1280×720. OV2740-class 1080p is often 1/6-inch and larger.
• IP67/IP68 and hermetic packaging when specified. No ISO 13485 / FDA claim here.
• 1 μm-class alignment and Class 10,000 cells are the miniature-build process, not a consumer camera line.

If you already have the CMOS part number and the tube drawing, send those two. Hangzhou will map them to a distal objective or say the OD cannot hold the chip and the LEDs. First-pass feasibility is 48 hours under NDA.

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