Optical Sensor + Reset Gear: The Safety Devices of the Brother TN 350 Toner Cartridge

The optical sensor built into the Brother MFC 7220 laser printer prompts the user when toner supply is really low. The sensor monitors toner supply levels by shining a light beam across a toner cartridge window. If no toner is detected, the ‘low toner’ light consequently blinks. The optical sensor works like the photo switch outfitted with streetlamps that switches on automatically during late afternoons (when the surroundings are dim) and turns the light off on early mornings when there is already sufficient natural light. Only that in the case of the toner cartridge, the amount of toner filling the chamber is employed to block the light beam delivered by the sensor; thus, the printer continues to operate. But once toner is depleted, the light beam connects, completes the circuit and the ‘low toner’ prompt appears.

Another safety feature of the Brother TN 350 toner cartridge is the reset gear that accurately monitors the number of pages printed by the printer. This counting device is activated depending on the number of revolutions made by the cartridge developer roller. Once the rated capacity is reached, the device turns off the printer automatically. It takes 18.5 revolutions of the developer roller to print a single page where a cartridge rated 2,500 pages (like the TN 350) actually makes 46,250 turns to complete the rated capacity. Once the developer roller reaches its revolution capacity, printing operations desists regardless of the amount of toner still left in the cartridge.

The mentioned safety features are integrated into the laser printer and toner cartridge combo to reduce the likelihood of damage to sensitive imaging components of the toner cartridge. These may all sound like a plus factor to printer manufacturers, but on the contrary these are integrated into the design to help sustain the cartridge's functional life cycle and on the aftermarket side, allow 3 or more toner refills on the cartridge. Without such devices, the cartridge will go on printing even when empty of toner, to eventually bring damage to the cartridge.

Printer manufacturers put in an extra 20% to total toner supply, precisely to bar the cartridge from printing when the toner chamber is empty. In case toner left in the cartridge is still more than half its capacity, then something must have triggered the cartridge to stop working. To override cartridge safety devices, the user will simply have to shake the cartridge vigorously to free clumped toner inside and so that printing could continue. In case the culprit is the developer roller, adjusting the reset gear would resolve the issue. However, if the cause of the stoppage is the optical sensor, placing a black electrical tape right across the cartridge window will solve the problem. But if printouts are diagnosed with fading prints, the primary cause therefore is low toner supply which can only be solved by replenishing the cartridge's toner supply with a compatible Brother toner refill kit.

Brother Toner Cartridges: Reset Gear Versus Reset Chip

Brother Industrial Corporation (BIC) is perhaps the only printer manufacturer that does not implement the ‘razor and razor blades’ mentality in the design of printer peripherals. In fact, BIC encourages refills on its toner cartridges and even provides users with step-by-step remanufacturing guidelines to extend a cartridge unit's capacity to over 3 print cycles. Moreover, BIC retained the reset gears in the design of their cartridges - in lieu of the more sophisticated microchips. This would allow users of Brother cartridges to simply adjust the reset gears to its starting position each time a refill is performed, which by the way reactivates the toner cartridge.

If reset chips are designed to control the printing process based on the number of printed pages, how does BIC implement this with the reset gear?

While cartridge yield is determined from the number of pages printed under a particular page coverage; calculation is based on the actual revolutions per minute (RPM) of the developer roller. For the Brother high yield black cartridge series, the maximum life of the developer roller is 110,000 revolutions or equivalent to 6,000 pages - at 18.5 revolutions necessary to complete the printing of a single page. Users can actually convert a high yield cartridge such as the TN-115 to a low yield TN 110 toner cartridge or vice versa, since only the reset gear controls the lifecycle of the Brother toner cartridge.

BIC’s laboratory tests confirm that the Brother HL 4040cn laser printer can detect if a new cartridge has been loaded; where the bias voltage is automatically set to high because of the tendency of new toner to print light. But as the cartridge is used regularly, density also increases. And to sustain this level all throughout the life of the cartridge, the density bias voltage is reduced accordingly. While users of non-Brother cartridges complain of how reset chips would desist printing while the cartridge still has sufficient toner supply, BIC can however assure its users that Brother reset gears will only respond when toner supply is really low or totally depleted.

Brother compatible reset gears (a.ka. flag gears) intended for starter cartridges are also available with Laser Tek Services. The flag gear resets the printer and eliminates the "Toner End Life" prompt so that a new cartridge cycle can commence.

A Look at the Brother ‘At Your Side’ Recycling Program

Brother International Corporation (BIC) has organized a responsible recycling program through its ‘AT YOUR SIDE’- corporate aphorism. The program aims to encourage Brother equipment and peripheral consumers to recycle used components such as empty toner cartridges by returning it back to BIC for proper recycling and disposal. Some of the returned printer peripherals are remanufactured while other metal and plastic components are broken down, reprocessed and used as raw materials for the manufacture of other printer parts.

To seal this noble intention geared at preserving the environment, BIC designed its recycling facilities to conform to ISO 14001 (International Organizations for Standardization) guidelines and consequently addressed pertinent environmental management concerns. The ISO is a series of standards that are relevant to environmental management systems. In fact, Brother selected five R’s as keywords intended to encapsulate the company’s environmental activity – REFUSE, REDUCE, REUSE, REFORM, and RECYCLE. This environmental program rightfully serves Brother’s stature as an environmentally responsible corporate citizen.

The Brother ‘AT YOUR SIDE’ recycling program accepts used laser printer toner cartridges and users are encouraged to deliver properly packed, empty printer cartridges to the different pick-up points designated around the country. Another option is to forward used consumables by mail (free of charge) using shipping labels that can be printed from Brother's recycling page on its website. Note however that unlike HP and Staples, Brother does not provide incentives, cash rewards or tax rebates for every toner cartridge returned.

Recycling at the personal level is easy with Brother consumables since all Brother OEM toner cartridges are provided with toner fill holes. Once the toner cartridge runs dry, a user will only have to open the fill hole by flipping the hopper plug off the toner chamber and pouring in fresh toner powder supplied by a toner refill kit. Now the refill process can be performed 3 to 4 times until the cartridge has reached its maximum effective print cycle. By then, the consumable can be forwarded to the Brother recycling plants for appropriate disposal.

Brother laser printer users have the distinct advantage over other printer users since the BIC takes proper care of its consumers by providing them not only user-friendly products but environmentally fine-tuned equipment as well.