All drivers know that there is a fuel gauge on the dashboard that allows you to predict the amount of oil remaining in your car, and there are dozens of liters in the volume of a car's mailbox, so placing a sensor on it is not a complicated technique. Printers are not the same, the printer cartridge is small, how can we know in the small ink cartridge how much ink left? Different companies have given a different approach, shopping malls that the battlefield, the protection of cartridges is to protect the core interests of enterprises, but Behind this is high technology.
How does the printer know that the ink is gone? By the exquisite design and high technology
The smaller the more difficult to achieve
Imagine driving on the highway, but finding that you have no fuel gauges, no oil at any time, or experience to estimate the need to refuel. This is obviously more blind, but in a very long time after the birth of the inkjet printer In fact, the mode of operation is almost like this, the user does not know how much ink cartridges left.
Early printers did not know how much ink left over
As a printer company, then Canon, Hewlett-Packard, IBM (later Lexmark) may have considered this issue, but the problem is more troublesome, the relevant patents are generally the 1990s, and ink-jet printers were sold in the 1980s Products, the time lag between the two is very long, while Epson's micro-piezoelectric technology was introduced after 1990 things.
Car fuel tank can use larger parts to achieve oil perception, but the printer cartridge is too small
Why is it tricky? Because the car fuel tank is large, a float and an uncomplicated variable resistor to solve the remaining fuel calculation problem, but the printer cartridge is small, these things can not get installed, can only think of other ways. The solution is similar to a car, but also through the electrode resistance measurement, when the ink decreases, the resistance will change.But so there is a condition that the ink must be conductive, and the ink of water is pure water is not conductive, the need for conductive Dyes, which limits the type of ink, and can lead to complications of cartridges being too costly.
Opaque printer cartridges and more
And most of the printer's ink is dye ink, so try to be opaque cartridges.How can we get in the closed box inside the number of ink left in the information? This article is through the analysis HP, Canon, Epson's patent to We explain how the printer knows how much ink there is.
HP and drop count
In 1995, China Hewlett-Packard applied for a patent to the Chinese Patent Office under the name of 'ink container with ink-hold detection circuit for ink-jet printing system and method of determining the amount of ink retained', China Patent No. CN 1151362 C.
The water-absorbing material in the ink cartridge prevents the ink from dripping out due to gravity
Here are some of the first clear is why the first ink cartridge inside a lot of polymer 'cotton' the same thing? Because the cartridge is down, the liquid characteristics is to be down, the cartridge must first protect themselves will not go Under the flow.It is necessary to know the earliest inkjet printing products are launched horizontally, so the solution is to make good use of surface tension, or negative pressure.
The left is the nozzle, using boiling heat to spray ink
At the heart of HP's patent is the drop count, and we know that thermal foaming technology works by having a resistor near the nozzle that heats the ink to cause the ink to boil and eject ink, which can be estimated by how much of the ink is fed to the print head It is one of the statistical methods to jet out the amount of ink.
Connect the head of the chip to the margin count
HP's core is to calculate the amount of ink droplets to obtain consumption information
Of course, this approach is not accurate enough, because the uniformity of jet ejected droplets of the same size, so easy to produce cumulative error is not allowed, so HP called this approximate count, which is an 8-bit binary data, It can be expressed as an exponent of 2, which is 256 bits.
HP will use precise statistics to load more ink than expected
Hewlett-Packard will conduct a test before the ink cartridge is produced, obtaining a data based on the amount of ink being injected and the number of drops ejected, which is called the exact count.The chip on the ink cartridge writes this data, that is, every 256 counts Full, it will trigger a precise count, the figure is 12.5% of the ink cartridges, which is one-eighth, then the 8-bit binary number and then start counting again, so after 8 times to put an ink cartridge consumption completed. There are also sensors inside the cartridge to detect the remaining ink, which is returned to the computer so that the computer knows how much ink was consumed and the driver can display the remaining ink.
Canon's red light
Canon printers, ink cartridges in the print head with the ink statistics algorithm and HP should be the same, which with Canon, Hewlett-Packard cooperation over the years are not unrelated, the two parties in the printing of patents have a variety of licensing methods, but Canon Some of the high-end ink cartridges, print head independent products, you can see the red ink cartridge placement.
Canon PRO-100 printer's red light
Each cartridge has a triangular prism on the bottom
This technique is carried out by the prism on the bottom of the ink cartridge and the LED for liquid level detection. Canon registered this patent in the United States in 1998 under the number US 6361136 B1. This technique is used to detect when the ink is about to run out The perception of the remaining ink, while the perception of depletion is the same as the method of measuring the number of drops.
Canon designed two programs that use the left prism on the product
Small prism at the bottom of the cartridge to enlarge the structure diagram
In the patent, Canon designed a variety of ink-sensing programs.And in the actual product, we see that Canon uses a small prism of the triangle. The details of this device shown in Figure, section can be seen on one side of the light-emitting device And the other side of the receiver.
Prism detection principle: there is no ink reflected light is not the same, the receiver knows
When there is no ink in the ink cartridge, this small triangular prism and the liquid will form a phenomenon similar to total reflection prism, so that the receiver on the other side receives a high signal intensity.When the ink level is higher than the prism When the light began to penetrate the prism scattering into the ink, the receiver detects the return of less light, so the machine will know the ink is enough.
Epson micro-piezoelectric shock detection
We know Epson is using a micro-piezoelectric print technology, which is completely different from Canon, Hewlett-Packard thermal foaming technology, he is based on the piezoelectric crystal deformation will be introduced from the page ink.This launch process, the liquid will form a shock, Epson's ink balance calculation is to use this shock. Epson's ink testing patent in China is CN 1380852A.
Epson principle of micro-piezoelectric: piezoelectric block will be deformed after extrusion ink extrusion, which will produce shock
Epson's calculation of the ink is inseparable from the estimation .This estimation is based on the size of the piezoelectric signal is already drop, because micro-piezoelectric technology for the control of these two states more accurately, so you can create a print based on how much ink The drop's estimate.
Epson has the same output voltage changes to determine the ink consumption
Epson Micro Piezo print head with a sensor, when a certain amount of ink with the print head, the piezoelectric device output will be a great change, the use of this change, you can know that the ink cartridge is empty and the cartridge is full Ink when the output is different between these two values to determine the more accurate consumption of ink.This data and the previous estimate of comparison, correction, you can more accurately know how much ink used.This data will be on the cartridge Constant accumulation of chips, and with the driver to provide users with a visual display of margin.
Ink cartridge display run out a little bit, but also the print head protection
No matter which way, we can see that there are unspeakable detection in the end how much, so the original intention of cartridge design is to ensure that as much as possible, there will be no consumption of ink, but The driver shows a little bit of ink phenomenon, the driver must be displayed ink has been prompted to replace, but the actual cartridge there is a little bit.This is also in the protection of the print head, such as thermal foam print head, the resistance is not dry Ink can make the print head easy to damage, and printer companies are perfusing more than about 10% more capacity than the nominal capacity as a cartridge when they are filled.
Insufficient fuel can run a period, but also the protection of the engine, the printer empathy
When you're on the road, look down at the fuel gauge, showing no oil, but the car can drive a distance, the printer's ink cartridge is the truth.
