Presence/absence on conveyors
Confirms a part left the nest before the next cycle starts.
Photoelectric · Square housing, 10 models
LFD61 Square Photoelectric Sensor Series
A 10-model square sensor family with one housing: retro-reflective to 3 m, diffuse to 300 mm, transparent-object detection, and through-beam to 10 m — all IP
Model LFD61-J / R / T · Brand LE Raun · Category: Photoelectric Sensors
Range100 mm – 10 m
Response≤2 ms
OutputNPN / PNP open collector
ProtectionIP65
Overview
One 25 × 50 mm housing carries the whole family, so a machine can mix detection methods without redesigning brackets. Retro-reflective versions need a reflector on the far side; diffuse versions read the object itself; through-beam versions put an emitter and receiver on opposite sides and give the longest range and the most reliable switching.The J-series models use a 650 nm infrared LED with a 5 ms response, which suits presence checking on a conveyor. The R and T models step up to 850 nm and 2 ms, giving the margin needed for small parts on a fast line. The J200-TM variant is the transparent-object detector: it compares the returned light against a background threshold, so a clear bottle triggers it while the conveyor behind does not.
Application scenarios
Transparent bottle and glass detection
The J200-TM reads a clear container against a background without a reflector.
Machine front guarding (non-safety)
A through-beam pair detects an obstruction without claiming a safety rating.
PCB and panel edge detection
Diffuse versions read board edges where a reflector cannot be mounted.
Door and gate position
Retro-reflective versions detect a reflector on the moving leaf.
Industries
- Packaging
- Electronics
- Logistics
- General machinery
Technical specifications
| Models | LFD61-J100/J300 (retro-reflective) · LFD61-J200-TM (transparent object) · LFD61-R10/R30 (diffuse) · LFD61-T200/T300/T500/T1000 (through-beam) |
|---|---|
| Detection method | Retro-reflective · diffuse-reflective · through-beam |
| Detection range | 0–1 m / 0–3 m adjustable (J100 / J300) · 200 mm adjustable (J200-TM) · 100 / 300 mm adjustable (R10 / R30) · 2 / 3 / 5 / 10 m fixed (T series) |
| Sensitivity adjustment | Single-turn adjuster (multi-turn potentiometer on J200-TM) |
| Output mode | NPN or PNP open collector |
| Switch mode | L.on / D.on switchable |
| Response time | ≤ 5 ms (J series) · ≤ 2 ms (R / T series) |
| Light source | Infrared LED 650 nm (J series) · 850 nm (R / T series) |
| Operating voltage | 12–24 VDC ±10% |
| Protection level | IP65 |
| Cable exit type | 2 m 4-core cable |
| Product application | Presence/absence detection for glass, PCB and other objects; suitable for complex application scenarios |
| Current consumption | ≤15 mA |
| Output current | ≤100 mA |
| Residual voltage | ≤1.5 V |
| Circuit protection | Short-circuit, reverse polarity, over-current |
| Ambient illumination | Incandescent ≤3,000 lux, sunlight ≤10,000 lux |
| Vibration / shock | 10–55 Hz 1.5 mm, 500 m/s² (X, Y, Z each 2 h) |
Dimensions
| Item | Value |
|---|---|
| Mounting holes | Ø3 mm, 25.4 mm pitch |
| Screws | M3 |
| Corner radius | R1 |
| Cable | 2 m, 4-core |
Wiring & output
| Lead | Colour |
|---|---|
| 2 | Blue |
| 3 | Black |
| 4 | White |
| — | Grey (5-wire types) |
How to specify
- 01
Choose the detection mode
Through-beam for the longest range and the most reliable operation in dust; retro-reflective for one-sided wiring over a few metres; diffuse for colour-independent presence at short range; background suppression where the conveyor or the machine frame sits behind the target.
- 02
Check the target and the background
A diffuse sensor sees the target, not the gap: a dark matt object halves the range. Background suppression types are set by distance, so the background must be at least 20 % further away than the target.
- 03
Match the light spot to the part
A 10 mm spot on a 2 mm wire gives a weak, unstable signal; choose a lens with a small spot at the working distance, or switch to a laser type.
- 04
Decide the output and the housing
NPN for Asian PLC inputs, PNP for European; 4-wire when the PLC needs both states. Square plastic for general use, stainless for washdown, fibre-optic where the space is too tight.
Why this series
One housing, four detection methods
Retro-reflective, diffuse, background-suppressed and through-beam versions share brackets and mounting holes.
Up to 10 m through-beam
Covers a wide conveyor or an open machine front with a single pair.
Adjustable sensitivity
A single-turn (or multi-turn) potentiometer sets the threshold for the actual target, not a nominal one.
Questions
Which detection method should I choose?
Retro-reflective when a reflector can be fitted and the target is opaque. Diffuse when only one side is accessible. Through-beam for the longest range or the most contaminated environment.
What does -TM mean on the J200?
Transparent-object detection with background suppression: it detects clear glass or film that a normal diffuse sensor would miss.
Are the models available in NPN and PNP?
Yes — add the (P) suffix for PNP; the base code is NPN.
Need a quotation for LFD61 Square?
Send your application details or the guard opening dimensions and we will specify the right model and configuration for your machine.