KEYENCE FU-77V Fiber Optic Sensor: High-Precision Detection Solution for Industrial Automation

January 28, 2026

Historical parts record: Photos and notes below belong to this record. Confirm the offered unit’s full model, condition and available test evidence before ordering.

The Keyence FU-77V is a coaxial reflective fiber-optic sensor head — two fiber cores in one black sheath ending in threaded stainless tips, mating with Keyence FS-series amplifiers. This delivery covers two purchases: four units (serials #057446029–032, January) and two more (#057446003–004, February), all new in the Keyence-format boxes with the Japanese mounting sheets, adapters, washers and nuts. The order record lists these as domestic replacement units built to the FU-77V pattern; the packaging and print follow the Keyence format, and we present it exactly that way.

What is in each box

Item	Detail
Sensor head	FU-77V, coaxial reflective, dual-fiber sheath, threaded stainless tips
Sleeve marking	KEYENCE FU-77V, ECO (green heat-shrink)
Adapter	Gray 6-hole block for φ10 mounting (per sheet 96M0179)
Hardware	Spring and flat washers, nuts in a sealed bag
Sheet	Japanese mounting instructions with the adapter cross-reference table

FU-77V kit layout — One kit laid out: the dual-fiber head with its green KEYENCE FU-77V ECO sleeve, the threaded tips, the Japanese sheet, the washers and nuts, and the gray adapter block on the box.

FU-77V sleeve marking — Sleeve close-up: KEYENCE FU-77V and the ECO mark on the green heat-shrink, tips threaded for bracket mounting.

The January batch — four kits

Four FU-77V kits — The four January kits, each bagged on its box with sheet and hardware.

Four FU-77V boxes — Box labels: KEYENCE FU-77V, unit code 00977V, serials #057446029 through #057446032 — a consecutive run.

Video: a kit turned on the bench — fiber coil, sleeve and hardware in turn.

The February batch — two kits

Two FU-77V boxes — The two February boxes: 00977V, serials #057446003 and #057446004.

Two FU-77V kits bagged — Both February kits bagged with sheets and hardware.

Video: a February kit opened on the bench.

Adapter and hardware

FU-77V adapter and sheet — The gray six-hole adapter block with sheet 96M0179 (Mounting the fiber unit of smaller diameter) and the washer set.

FU-77V hardware bag — Hardware in the bag above the coiled fiber: adapter block, washers and nuts for the threaded tips.

FU-77V kit with adapter — One more kit angle — fiber coil, adapter, hardware, box.

Instructions and cross-reference

FU-77V Japanese sheet — The Japanese sheet close-up: 同軸反射型ファイバユニットの取付け方法 (mounting the coaxial reflective fiber unit), with the adapter table — φ13 uses OP-26501, the φ10 block here matches the OP-26500 row, and the connection examples list FU-32/FU-35FA and FU-59/FU-48. The coaxial note matters: on this head type, keep the emit and receive sides per the sheet or detection flips.

FU-77V coil and tips — The fiber coil with both threaded tips free — dress the coil with the supplied tie, leave the bend radius loose.

FU-77V another angle — Final angle: the coil, adapter and hardware as packed.

Mounting notes

Coaxial reflective heads tolerate target-color changes better than through-beam pairs at close range, which is why they end up on label and mark detection. Thread the tips into a bracket or use the six-hole adapter for amplifier-side mounting; the washers take up the bracket thickness. Insert both fibers fully into the amplifier, close the lever, and only then set sensitivity — the quick-release lever half-seated is the classic unstable-detection fault the sheet warns about.

Condition and delivery facts

Six kits total, new and bagged, sheets and hardware complete. First purchase of 4 received 2026-01-26 (a mis-shipped lot that was resold at 13 yuan each plus freight), second purchase of 2 on 2026-02-27 at the same unit price; 0.5 kg per kit.