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What Is a Seamless Pipe?

A seamless pipe is a pipe with no joints in the longitudinal direction of the pipe.

Steel pipes are generally manufactured by rounding steel plates into a cylindrical shape and welding them together. However, the presence of joints in pipes can lead to serious accidents in terms of strength and reliability, such as crude oil leaking from pipes depending on the intended use.

Seamless pipes are manufactured using the Mannesmann method or other methods that do not produce joints that could cause a reduction in strength. Since there is no risk of defects occurring at joints, seamless pipes are used when high strength and reliability are required.

Uses of Seamless Pipes

Seamless pipes are widely used to transport fluids such as gas, oil, and water. There are also many types of seamless steel pipes, as there are also pipes for construction applications.

• Seamless Pipes for Construction
• Seamless Steel Pipes for Fluid Conveying
• Seamless steel pipes for high-pressure boilers
• Cold-drawn precision seamless steel pipe

Since the materials and standards of seamless pipes vary depending on the application, it is necessary to select the seamless pipe that best suits each purpose. Examples of specific applications include oil and natural gas facilities, boiler tubes for thermal power plants, and high-pressure piping for industrial machinery.

Principle of Seamless Pipes

The Mannesmann process is the typical manufacturing method for producing seamless pipe. It is the most productive way to produce seamless pipe. Simply put, the Mannesmann method forms pipes from round bars, not steel plates. Since the pipe is formed from a round bar, no joints are created.

In the mannequin method, the material for the round bar-shaped pipe, called billet, is first heated to a high temperature (about 1,300°C) until it becomes bright red. When the billet is ready to be rolled, a tool called a plug (for seamless pipe bore forming) is pressed against the center of the billet to form it into a pipe.

If the plug is just pressed against the billet as it is, the billet will be pushed out to the outside and will not be formed into a pipe shape. Therefore, the billet is formed by holding the outer circumference with rolls such as cone and barrel molds. The material pushed out by the plug is pushed forward, so the outside shape can be formed while the inside diameter is formed.

In general, severe rolling of hot billets inevitably results in deterioration of surface properties. Similarly, thick-walled products, which are subjected to a lighter rolling process, are relatively easier to produce. However, there are now companies that specialize in thin-wall processing despite seamless piping. They range from ultra-thin small-diameter seamless pipes with a thickness of 0.08 mm to large-diameter seamless pipes with a diameter of 426.0 mm, the largest diameter ever manufactured in Japan.

Other Information on Seamless Pipes

1. The Difference Between Seamless Pipe and Welded Pipe

The difference between seamless pipe and welded pipe is the use of welding in the pipe manufacturing process. The reason why seamless pipe is needed in the first place is that “grooved corrosion” occurs at welded joints.

This groove corrosion is a V-shaped corrosion that occurs on the weld (inside) of the pipe. Because welding is generally accompanied by high temperatures, changes in the metallurgical structure of the joint are inevitable. The difference in microstructure between the weld and the base metal causes a potential difference, which in turn causes corrosion. Once corrosion occurs, the formation of grooves accelerates corrosion, which eventually reaches the surface of the pipe or leads to fluid leakage due to lack of strength. This is the mechanism of grooved corrosion.

The primary reason for selecting seamless pipes is to prevent groove corrosion, but there is also a type of welded pipe called groove corrosion-resistant steel pipe. Groove corrosion-resistant steel pipes are made by adjusting the molecular composition of the base material (reducing sulfur content) and adding special elements to the weld zone. They are more expensive than ordinary pipes, but not as expensive as seamless pipes, and are widely used for liquids that pose no risk of leakage, such as water.

2. Price Difference Between Seamless Pipe and Welded Pipe

This section describes the price difference between seamless pipe and welded pipe (ERW pipe is used here as an example). Here, as an example, we consider SUS304 as the material. The price of a seamless pipe is about 1.5~2 times higher than that of an ERW pipe. The price difference is small when the pipe diameter is small, but the larger the diameter, the larger the price difference.

When considering a whole plant, the price of piping alone is 1.5~2 times higher than that of a single pipe, so the price difference is not that great when replacing a part of the piping, but when constructing a new plant, the overall cost changes significantly. Therefore, it is important to select appropriate piping according to the fluid to be handled to reduce costs.

What Is a Digital (Video) Microscope?

A digital microscope (or video microscope) is an instrument used to magnify an object for observation. However, the term digital microscope generally refers to a microscope equipped with a digital camera and is distinguished from an optical video microscope. Compared to optical video microscopes, digital microscopes have a deeper depth of focus and the ability to measure angles and lengths, which are their main features.

An optical microscope has two lenses, an objective lens, and an eyepiece, while digital microscopes have only an objective lens, and the part corresponding to the eyepiece lens is a digital camera. This can be said to be the most significant difference between an optical microscope and a digital microscope. The digital microscope usually projects the observed object on a monitor.

Several models are available from various manufacturers, with magnifications ranging from several times to several thousand times.

Uses of Digital Microscopes

Video microscopes are used not only for magnifying and observing objects but also for evaluations and analyses based on the obtained image data.

They have been introduced in varied fields such as the automotive and aviation industries, the electronic device industries, the medical and cosmetic industries, and the chemical and material industries, and are used in a wide range of applications from research and development to quality assurance.

For example, in failure analysis of electronic components, digital microscopes can be used to inspect the appearance of IC chips, analyze failures of defective products, inspect foreign objects, and analyze their size and shape.

Principle of Digital Microscopes

In a digital microscope, an object is magnified by an optical lens (objective lens), and the part that corresponds to the human eye in optical microscopes is a digital camera. The image magnified by the optical lens is detected by the image sensor and the image is displayed on a monitor.

The magnifying power of optical microscopes is expressed as the product of the magnifying power of the objective lens and the eyepiece. In the case of digital microscopes, however, the size of the monitor and the size of the image sensor of the camera affect the magnifying power, which is different from the concept of magnifying power of optical video microscopes. Digital microscope’s magnification is also expressed as the product of the magnification of the objective lens and the magnification of the monitor. The magnifying power of the monitor is calculated by dividing the monitor size by the image sensor size.

In addition to magnification, resolution, or the ability to distinguish details, it is necessary to observe an object in greater detail. If the resolution is not sufficient, the observed image will be blurred and details cannot be observed clearly. In the case of digital microscopes, the resolution of the objective lens, the resolution of the optical lens of the digital camera, the resolution of the image sensor, and the resolution of the monitor all affect the resolution.

It is necessary to select a model that provides optimal magnification and resolution according to the object to be observed and the purpose. To meet user requirements for these advanced resolution processing capabilities, 4K monitor-type images have recently been introduced.

Other Information About Digital Microscopes

1. Use of Digital Microscopes in Dentistry

One of the applications of digital microscopes is in dentistry. By taking advantage of the focusing function of digital microscopes, it is possible to observe minute-affected areas that are difficult to detect with the naked eye.

In particular, when performing root canal therapy, which is the complete removal of caries, digital microscopes are used to make it possible for the dentist to remove as much of the affected area as possible. 

The use of digital microscopes improves the quality of treatment and reduces the risk of recurrence due to overlooked areas. However, it should be noted that dental treatment using video microscopes is, in principle, not covered by insurance and must be paid out-of-pocket.

2. Cosmetic Use of Digital Microscopes

Digital microscopes are also used for cosmetic-related treatments and diagnoses, such as cosmetic surgery and scalp checkups. By looking at the skin under microscopic magnification, details such as dryness of the skin and the development of the hairline can be observed.

Clients undergoing cosmetic surgery can also gain a sense of satisfaction from the medical examination by being able to check the condition of their skin and scalp on the screen. It also motivates the client to improve their condition. 

3. Examples of Functions of the Latest Digital Microscopes

Digital microscopes are nowadays often used for detailed analysis of the inside of electronic components and semiconductor ICs down to a few microns, replacing scanning electron microscopes (SEM), which require observation in a vacuum. For this purpose, for practical use, it is necessary to increase magnification and resolution by orders of magnitude from a few millimeters to a few microns during observation.

This operation requires changing the objective lens as in optical video microscopes, but some digital microscopes in recent years have built-in automatic rotation for lens change and automatic focusing function for lens change, making this process almost fully automatic.

In terms of image processing, there are now highly functional types that can combine images with high magnification into a single large image by arranging them vertically and horizontally like tatami mats, and that can process an object into a three-dimensional (3D) image by utilizing the image focus adjustment function.

There are examples where digital microscopes are used to check the wiring of semiconductor ICs and to analyze internal defects in electronic components by combining these functions.

4. Digital Microscope Prices

The price of digital (or video) microscopes varies depending on their applications and performance. Digital microscopes with a narrow range of magnification and field of view start at around 10,000 yen, while those used for beauty molding or simple inspection of the scalp are priced at around 50,000 yen, and those used for medical purposes are in the 100,000 yen or more range.

Furthermore, digital microscopes such as those used for product inspection in the manufacturing industry, such as semiconductor manufacturing, require high magnification and micron-level magnification, high-resolution image display, so the price range is generally in the several million yen range.

Low latency screen display and high frame rate are also important for use in surgery and treatment, but digital microscopes with low latency and high frame rate tend to be priced higher. In addition, there are products on the market that allow the magnification of the display to be enlarged by changing the lens. In this case, the image processing capability is also advanced, and the price increases further due to the need for a dedicated monitor and sophisticated control software.

What Is a Seam Welder?

A seam welder is a machine that performs welding by pressure welding. It is used in fusion welding, pressure welding, and brazing, applying pressure to heated metals to join them. Seam welders enable high-precision welding with less dependence on the welder’s technical skills.

Uses of Seam Welders

Seam welders are essential for manufacturing products requiring airtight seals, such as canned juice, food, and fuel tanks. They are also used in producing cases for sensors and electronic devices that must be sealed from the outside air. This includes quartz devices and MEMS, which integrate semiconductors, sensors, actuators, and electronic circuits. In the automotive industry, seam welding is utilized to enhance the rigidity of fuel tanks and structural components, offering continuous joints that increase body strength compared to spot welding.

Principle of Seam Welders

Seam welders join materials by sandwiching them between two roller electrodes that transmit an electric current, melting and fusing the parts with applied pressure. The process achieves continuous sealing by rotating the rollers, with the machine settings, such as welding speed and current magnitude, predetermined for automatic operation. Suitable for welding thin plates, seam welding is a type of resistance welding that relies on electrical resistance to generate heat.

Other Information on Seam Welders

1. Advantages of Seam Welding

• Accessible to operators without advanced skills, thanks to preset conditions on the seam welder.
• The pre-joining accuracy of the flange portion is less critical, as it is adjusted between rollers during welding.
• Offers a safer working environment with no sparks or flashes common in other welding processes.

2. Disadvantages of Seam Welding

Seam welding requires significant initial investment due to the size and cost of seam welders, and the process consumes considerable electricity due to the heat generated by electrical resistance.

What Is a Sequencer?

A sequencer, also called a programmable logic controller (PLC), is a device that controls the operation of a machine according to a programmed condition or sequence.

Its name comes from the sense of something that moves a machine in sequence. In recent years, sequencers can also control analog signals such as pressure and communicate information between devices.

Uses of Sequencers

Sequencers are mainly used industrially. They can be found in a wide variety of applications, ranging from heavy industrial infrastructure such as power plants and waste disposal plants to processing plants that make microchips. Sequencers are mainly used to automate machinery and equipment. They allow machines to automatically perform repetitive operations, thus saving labor.

Home appliances such as washing machines also use sequence control, but microcomputers are used for the control devices. This is because it is more economical to use microcomputers for mass-produced machines. Sequencers are often used for certain industrial equipment, and in everyday life, you may see them in the driver’s seat of a train.

Principle of Sequencers

A sequencer consists of a power supply unit, board, input unit, output unit, memory, and arithmetic unit (CPU). The internal drive power supply of the sequencer is a weak DC voltage; a commercial power supply of about 100 VAC to 240 VAC is converted to a weak DC voltage in the power supply section.

The power supplied from the power supply unit is distributed to each part by the board. The board also transmits input/output signals from the arithmetic section to the input/output section. Input signals from sensors and pushbutton contacts are transmitted to the input section of the sequencer. Depending on the type of input section, contact digital signals or voltage analog signals can be input.

In the sequencer, decisions are made based on a program written in advance by the arithmetic section. The arithmetic section constantly scans the program at ultra-high speed. When an output decision is made by the program, an output signal is sent from the output section of the sequencer.

The output signals are used to operate motors, lamps, and other devices. Like inputs, output signals can be analog or digital outputs. Programs and input/output devices on/off information are temporarily stored in the sequencer’s memory. The ladder diagram method, in which the sequence circuit is logicized, is frequently used for the program.

Programming tools exist for each device of each company, and these tools are used to edit the program. Inside the sequencer, analog signals are also treated as digital signals. Digital signals refer to data represented only by 0s and 1s, while analog signals represent not only 1s and 0s but also continuous data. Examples of analog data include measuring instruments such as thermometers and pressure gauges.

Advantages of Using Sequencers

The greatest advantage of using a sequencer is the labor-saving wiring for control. In the case of digital input/output only, it can be reproduced by a relay circuit without using a sequencer. However, if relay circuits are used for complex control, the wiring becomes more complicated, and production and maintenance take an enormous amount of time. In complex control, sequencers are often used for labor and cost reasons.

In recent years, automatic data collection and complex signal processing can also be realized with sequencers. Some devices can communicate with the Internet via an Ethernet port or wirelessly with a PC. Sequencers have also become more reliable, with redundant power supplies and arithmetic units becoming possible. Today, sequencers are indispensable in industrial settings.

What Is Electronic Load?

An Electronic Load is a device that is connected to the device under test and functions as a load resistor.

Conventionally, a resistor was connected to the device under test and used as the load, but the resistor had to be replaced every time the resistance value was changed. The advantage of an Electronic Load is that the load size can be set arbitrarily.

By using an external controller, the load setting can be switched at high speed. In addition, there are functions such as constant-current mode, in which a constant current is applied from the device under test, and constant-voltage mode, in which the output voltage of the device under test is maintained at a constant level, making it suitable for a variety of measurements and tests.

Applications of Electronic Loads

Electronic Loads are used for performance evaluation tests and product inspections of electronic circuits, power supplies, batteries, and other devices. Specifically, the following are some of the uses of electronic loads:

• Driving capability of Electronic Loads in electronic circuits.
• Load characteristic testing of power supplies.
• Charge/discharge testing of batteries.

In addition, since the load can be controlled by an external controller, it can be used to automate testing, such as by changing the load conditions to suit the purpose.

Functions of Electronic Load

Electronic Load has a built-in amplifier composed of a bipolar transistor or FET that controls the current (load current) drawn into it. The characteristic functions are described below.

1. Power Consumption/Conversion Method

The method of power consumption and conversion depends on the type of Electronic Load.

Thermal Conversion Type Electronic Load
The power consumed in Electronic Load is converted into heat by the semiconductor elements that make up the amplifier. This is apparently the same effect as when current flows through a resistor, but since the semiconductor elements generate heat, a heat dissipation mechanism is required.

Power Regenerative Electronic Load
Electric power input into an Electronic Load is converted into alternating current by an inverter. Since the converted current is returned to the power distribution network, power consumption is small and heat dissipation is relatively simple. However, since the regenerated power energy is returned to the power grid, it is limited to environments where grid-connected operation is possible.

2. Electronic Load Operating Modes

In general, Electronic Loads are equipped with the following four modes, and the most appropriate mode is selected according to the purpose of the test:

Constant Current Mode
In this mode, the Electronic Load operates with a set constant current, regardless of its input voltage. The Electronic Load is adapted so that the load current remains constant even when the output voltage of the device under test fluctuates.

Constant Resister Mode
In this mode, the set resistance value is held constant like a fixed resistance. It is characterized by maintaining the set resistance value except during the transient period immediately after power-on. This mode is useful for conducting capacity tests on batteries, star-tup tests for electronic equipment, and other scenarios where load current needs to vary linearly with input voltage.

Constant Voltage Mode
This mode maintains the output voltage of the device under test at a constant value. When the output voltage of the device under test fluctuates, the Electronic Load changes the load current to maintain a constant output voltage. As a result, the output voltage of the device under test remains constant, although the load current fluctuates.

It is often used for testing fuel cells and battery chargers, among other. In battery charger testing, complex battery voltage behavior can be reproduced and tested with Electronic Loads.

Constant Power mode

In this mode, the Electronic Load works to consume the set power. First, the voltage of the device under test is measured, the current value is calculated based on that voltage and the set power value, and the current is drawn accordingly.

How to Select an Electronic Load

Electronic Loads are indispensable in the development and production of power sources such as power supplies and batteries when testing the performance of each device. The following are some considerations when selecting an Electronic Load device: 

1. Power Capacity and Withstand Voltage

If the device under test is a power supply, it should, in principle, have a power capacity that covers its maximum output power. The withstand voltage specification must also be greater than or equal to the voltage that may actually be applied to the device. 

2. Minimum Voltage That an Electronic Load Device Can Handle

Electronic Loads are generally difficult to use in the lower voltage range, and the minimum voltage that an Electronic Load can handle is called the minimum operating voltage. As mentioned above, Electronic Loads control the current that flows through an amplifier composed of a bipolar transistor or FET. Therefore, if the voltage is below the voltage at which that amplifier operates, the Electronic Load will not operate properly.

As a result, the current cannot be drawn at a lower voltage than a certain voltage. That is, if the voltage at both ends of the Electronic Load is lower than the minimum operating voltage, it will not operate.

3.Ambient Temperature and Time

For Electronic Loads, attention should be paid to the specifications of the ambient temperature that guarantees the maximum load. In particular, it must be taken into account that thermally-converted Electronic Loads are limited to use at high temperatures because the ambient temperature rises due to their own heat generation.

In addition, there may be a limit to the time that the maximum load can be maintained, so it is necessary to check the descriptions in catalogs and spec sheets in advance.

What Is a Permalloy?

A Permalloy is a type of nickel-iron alloy, especially one with a nickel content of 35-80%.

The name Permalloy is common, but the official name defined by the Japanese Industrial Standard JIS C 2531 is an iron-nickel soft magnetic material. A Permalloy has a low coercivity and high permeability and has the characteristics of a high magnetic shielding effect and a high magnetic focusing effect.

Another property is that it can exhibit high magnetization when a fine magnetic field is applied, and it also increases the impedance in AC circuits.

Uses of Permalloys

Permalloys are used to prevent magnetic leakage from magnetic heads installed in magnetic recording devices such as TVs, PCs, videotapes, and hard disks. The aforementioned properties make permalloys suitable as a magnetic shielding material.

In addition, biomagnetic measurement, a next-generation diagnostic method that has been attracting attention in recent years, requires the measurement of extremely weak magnetic fields and must be shielded from the effects of environmental magnetic fields. Therefore, a magnetically shielded room with permalloy magnetic shielding has been installed to prevent the influence of environmental magnetic fields.

Principle of Permalloys

Permalloys are a type of nickel-iron alloy with a nickel content of 35-80%, but raw permalloys do not have a very high magnetic permeability. Permalloys undergo a process called “magnetic annealing” and “strain relief burning.”

1. Magnetic Annealing

Magnetic annealing is a heat treatment to remove oxide films, etc., which prevents the movement of magnetic domains where the magnetic moment of the atoms in permalloys are aligned. This removal of impurities allows the external magnetic domains to move.

The removal of these impurities promotes the movement of magnetic walls and rotation of magnetic domains when an external magnetic field is applied, thereby improving soft magnetic properties. The magnetic permeability of permalloys after magnetic annealing is about 100 times higher than that of permalloys before magnetic annealing.

2. Strain-Relief Burning

Straining and burning is a process performed at lower temperatures than magnetic annealing to remove residual stress by recrystallization. The purpose is to make it easier to process. It is also possible to achieve even higher magnetic permeability by adding molybdenum, copper, or chromium.

Other Information on Permalloys

1. Main Types of Permalloys and Magnetic Properties

There are several types of permalloys, which are used for different purposes. Two of the most commonly used are Permalloy B (PB) and Permalloy C (PC), where PB is a binary alloy of iron and nickel and PC is a multi-alloy of iron, nickel, molybdenum (Mo) and copper (Cu).

In magnetic materials, the higher the saturation magnetization Bs, which indicates the absolute value of magnetic force, the more suitable the material is for magnetic shielding in strong magnetic fields. On the other hand, the larger the magnetic permeability μ (the larger the maximum permeability near saturation magnetization Bs), the more suitable it is for magnetic shielding in weak magnetic fields because it can respond to changes in weak magnetic fields.

In this case, the maximum permeability of PB and PC are 50,000 and 180,000, respectively, and the saturation magnetization Bs is 1.55T for PB and 1.72T for PC. In other words, PB with large saturation magnetization is suitable for shielding in strong magnetic fields, while PC with large permeability is suitable for shielding in weak magnetic fields.

2. Practical examples of Permalloy Cores

In addition to its function as a magnetic shield as described above, permalloys also have a function as a core that detects weak magnetic fields increases the magnetic flux for output, and is used as a core for current sensors and transformers. A current sensor is a sensor for measuring electric current. When current flows through a conductor, magnetic flux is induced in the core, and the magnitude of the magnetic field is used to measure the current value.

A transformer is a device for converting voltage and insulating between circuits; it consists of an input coil and an output coil wound independently on a single core, and when current flows in the input coil, voltage is output to the output coil by the nature of electromagnetic induction. The use of Permalloys, which have high magnetic permeability, makes it possible to downsize the transformer. 

3. Workability of Permalloys

Permalloys are flexibly deformable and have excellent workability. Like other metals, it can be processed by bending, cutting, pressing, and punching. However, nickel alloys, of which permalloys are a part, are representative of materials that are generally considered difficult to cut. For this reason, cutting permalloys requires a high level of technical skill.

Permalloys are widely used in magnetic shields, measuring instruments, magnetic heads, audio equipment, communication cables, etc., and are processed and used in a variety of shapes, including cylindrical, plate, ring, wire, and foil shapes, depending on the application.

What Is a Mobile Robot?

A mobile robot is a robot that can perform simple transportation tasks.

In recent years, mobile robots have been introduced in a great number of workplaces, but in the past, conveyance tasks such as moving products on production lines were mainly performed by human operators. However, as technology has developed, the need for automation has increased, and mobile robots have become widely used at many production sites, helping to reduce human resources and improve productivity.

As a result, mobile robots have become widely used in many production sites, freeing workers from the heavy and simple tasks of simply transporting goods, and providing greater benefits in terms of safety and quality. Recently, more and more robots are equipped with AI functions, and they themselves are able to determine the best route and transport packages to a predetermined location.

Uses of Mobile Robots

Mobile robots are widely used in factories, not only for transportation but also for replacing tasks traditionally performed by humans.

1. Automobile Parts Manufacturing Plants

Mobile robots are used to transport heavy parts and perform simple tasks that are prone to errors and omissions when performed by humans. Also, by combining automatic control devices, it is possible to program the start, stop, and movement of operations.

2. Semiconductor Factories

In semiconductor factories, the system can efficiently transport products in cramped spaces, avoiding congestion and obstacles. This helps to reduce human resources and time in the factory.

3. Food Factories

Production lines in food factories often change with the seasons or with the release of new products. By introducing Mobile Robot, the factory can flexibly respond to time-consuming production line changes without having to spend human resources and time. Some factories are also unmanned because they can pack bags, boxes, and apply labels.

4. Distribution Warehouses

Robot controllers are ideal for logistics factories where a lot of goods come and go. The robot’s current position and operating status can be monitored to ensure efficient transport and prevent errors.

Principle of Mobile Robot

Mobile robots vary in individual performance. In this article, we will describe four functions and principles of Mobile Robots dedicated to conveyance that do not require magnetic tape, etc.

1. Safe Traveling

The built-in laser scanner provides 360-degree visibility, allowing the robot to determine its own path and avoid obstacles to avoid collisions. In addition, sensors on both sides, back, and low front prevent collisions.

2. Robustness

By attaching a sturdy metal cover, etc., the robot can transport heavy loads. Some of the largest Mobile Robots can transport loads as heavy as 1.5 tons.

3. Monitoring Function

When multiple robots are used, their movements can be monitored and controlled in real time. Map information can be input to the robot, and instructions can be given to multiple robots at once using communication devices.

4. Safety Function

The power on/off button, as well as the emergency stop button, is provided for an emergency stop. Robots with carts and touch screens are also available.

Other Information on Mobile Robots

Mobile Robot Market

The market for mobile robots is becoming more and more active every year. This is due to the labor shortages faced by developed countries such as Japan and the need for social distance due to the new coronavirus that has recently been raging around the world, and the increasing number of companies around the world that are actively moving to manpower reduction.

The number of companies entering the market is increasing each year due to the flexibility and wider range of specifications that robots can offer, and it is expected that robots will be introduced in production sites other than food, semiconductor, and automotive fixture factories.

What Is a Production Printer?

A production printer is a large printer that prints commercial and in-house printed materials at high speed and with high accuracy.

They are characterized by their ability to handle various sizes of printed materials, as well as a wide range of paper thicknesses and materials. Production printers enable companies to produce vivid, colorful printed materials in-house and reduce costs for business cards, envelopes, clear files, and sales paper, which are often consumed.

Uses for Production Printers

Production printer applications include printing large quantities of presentation materials, high-speed printing of color photographs, business cards, brochures, invitations, envelopes with designs, printing of product packaging, posters for advertising, and clear files with designs.

Vivid printing can be done at high speed on a wide variety of printed materials. When selecting production printers, it is necessary to fully consider the necessary functions, etc., since these products are very expensive, costing about 10 million yen per unit.

Principle of Production Printers

Production printers are mainly composed of a paper feeder, a photoconductor drum, a fusing process unit, a binding system, and a device that transports the printed materials to the respective mechanisms. The paper feeder of production printers feeds a variety of print materials to the fusing process unit and other devices.

To accommodate a wide variety of printed materials, each printer uses air to vibrate and roll up the printed materials for smooth feeding at high speed.

In the photoconductor drum, light is converted into an electrical charge and toner is adsorbed by giving static electricity to the object to be printed. In the fusing process equipment, the toner transferred by the photoconductor drum is fixed by heat treatment. Again, the degree of fusing during heat treatment is changed to accommodate various types of printed materials.

In the bookbinding system, when the printed material needs to be closed, such as a pamphlet, it is bound by heat treatment or by punching holes.

Production Printers Market

In recent years, the market for production printers has been changing.

For example, printed materials (brochures, invitations, direct mail) as a means of reaching customers are being replaced by online advertisements that appear on portal sites and search engines as smartphones become more widespread. At the same time, the paper data output of bookkeeping documents related to corporate business transactions is being replaced by decentralized processing using multifunction office equipment or is even becoming unnecessary due to the trend toward paperless printing. Thus, the market for production printers has been shrinking for a while.

On the other hand, industrial-use high-speed inkjet printers, which have been introduced continuously since around 2010, have grown to account for one-third of the production printers market (figures according to Yano Research Institute Ltd.). The reason for this growth is that inkjet printers do not come into direct contact with paper or other materials, and can therefore print on cloth and cardboard, which were previously impossible to print on. The emergence of high-speed inkjet printers for industrial use has opened up new markets that production printers had not previously targeted, such as printing on clothing and small-lot packages for confectionery, and the market shrinkage trend is slowing.

Production Printers and POD

Print-on-demand (POD) is a technology that prints the required number of copies at the required time.

In the past, production printing was done by analog means (e.g., letterpress printing, as used for newspaper printing. It refers to the printing of large quantities of prints with the same content using analog means (e.g., letterpress, as used in newspaper printing, which offers superior image quality). In recent years, advances in digital technology and MEMS technology (micro-electro-mechanical systems) have brought POD-capable production printers to the market, with expressive capabilities that exceed those of printed materials such as posters in terms of image quality.

POD is also expected to contribute to market expansion in the future, as it allows printing customer names directly on brochures and direct mail, and printing advertising images tailored to customer preferences, one sheet at a time.

What Is a CMOS Sensor?

A CMOS sensor is an image sensor used in digital cameras and other photographic equipment. The light received by the individual photodetectors is converted into an electric charge, which is then passed through an amplifier circuit composed of CMOS and extracted as a voltage or current according to the intensity of the light.

In the past, CCD sensors were used as the mainstream image sensor, featuring a structure in which the charge is transferred by the CCD and converted to a voltage via a floating diffusion amplifier (FDA).

CCD sensors have advantages over CMOS sensors in terms of sensitivity, signal-to-noise ratio, and low dark current, but they have disadvantages in terms of complex power supply configuration, unavoidable smear generation, and the fact that the manufacturing process is special and general CMOS LSI production equipment cannot be used. Recently, CMOS sensors have become the mainstay of image sensors due to advances in methods for reducing the effects of dark current and improving the signal-to-noise ratio in CMOS sensors.

Uses of CMOS Sensors

In the past, CMOS sensors were used in cameras mounted on smartphones and tablets because of their low cost of production. On the other hand, CCD sensors with low noise were mainly used in single-lens reflex cameras and video cameras, which require high image quality.

However, as noise reduction methods for CCD sensors evolved, the smear and blooming that had been a problem with CCD sensors did not occur, and the CCD sensor was gradually replaced by the CMOS sensors. CMOS sensors are now used as image sensors in all types of photographic equipment.

Principle of CMOS Sensors

The basic function of an image sensor is to store and transfer the electric charge generated by the light-receiving elements arranged in large numbers on its surface, convert it into a voltage or electric current, and output it. In this respect, CCD sensors and CMOS sensors share the same function.

The major difference between the two lies in the charge transfer mechanism: CCD sensors have a grid of photodiodes as light-receiving elements, and charge can be temporarily stored in the N-type region of these photodiodes.

A vertical CCD is placed adjacent to these photodiodes, and all the charges accumulated by each photodiode at a given time are simultaneously transferred to the vertical CCD. The charges are sequentially transferred and delivered to the horizontal CCD.

The horizontal CCD transfers the charge transferred from the vertical CCD to the FDA, which outputs a voltage corresponding to the amount of charge, thus providing a voltage output corresponding to the intensity of the light irradiating the photodiodes. As described above, in a CCD sensor, the amount of charge from all photodiodes is output sequentially.

On the other hand, CMOS sensors have a photodiode, an amplifier that amplifies the output of the photodiode, and a switch element that connects the amplifier output to the signal line, so that light reception, conversion, amplification, and output are performed for each photodiode.

From this configuration, CMOS sensors can specify individual photodiodes by combining horizontal and vertical scanning signals and can extract voltage or current according to the amount of charge. Thus, any photodiode can be selected and its signal be read out.

Due to these structural differences, CMOS sensors have the advantage of high-speed readout by limiting the signal to the necessary area and eliminating the transfer noise of CCDs. Furthermore, while CCD sensors inevitably suffer from smears caused by noise components flowing into the CCD, this is not the case with CMOS sensors.

CMOS Sensors Structure

CMOS sensors combine a photodiode, which is a light-receiving element, with an amplifier and switch elements, and integrate many of these elements. The photodiode manufacturing process is special and different from that of transistors, but the other components are identical to those of CMOS LSIs, so the use of CMOS manufacturing equipment is advantageous over CCDs.

New developments are also emerging about photodiode placement. In this structure, photodiodes are placed on the backside of the CCD, whereas circuits such as amplifiers and switch elements are formed on the front side. The photodiode is connected to the circuitry via internal wiring. Although the manufacturing process is more complex, the photodiodes can be placed with no gaps between them, which improves light collection efficiency.

The circuitry in CMOS sensors operates with a single power supply, so basically only a single power supply of about 3.3 V is required. CMOS sensors have an advantage in terms of power consumption.

Other Information on CMOS Sensors

1. CMOS Sensors Market share

Sony had a dominant market share when CCD sensors were at their peak, but now that CMOS sensors have become the mainstay and their primary application has shifted to smartphones, Sony’s market share is gradually declining. In 2021, Sony’s market share in terms of value will be 45%, Samsung’s 26%, and OmniVision’s 11%, according to the survey.

2. Size of CMOS Sensors

CMOS image sensors are available in a variety of sizes, from large to small. Taking Canon’s CMOS image sensors as an example, there are six different sizes of image sensors.

• 35mm full size (approx. 36mm x 24mm)
• APS-H size (approx. 29 mm x 19 mm)
• APS-C size (approx. 22 mm x 15 mm)

However, they are not sold to the general public and are limited to use for their cameras.

• 1 inch
• 2/3 inch
• 1/1.8 inch

Generally, for the same number of pixels, the larger the sensor size, the better the image quality. Also, the wider the aperture, the higher the sensitivity.

What Is an LED Driver?

An LED driver is an integrated circuit (IC) that stably drives and safely controls LEDs. LEDs emit varying amounts of light depending on the current value, and the current value varies depending on the color of the LED, so stable driving requires highly accurate current control. For this reason, control by a constant-current circuit is extremely important, and this is the main function of the LED driver.

Uses of LED Drivers

As the name suggests, LED drivers are used to drive and control LEDs. In recent years, however, LEDs with low power consumption and long life have become the mainstream for lighting fixtures instead of fluorescent lamps, and many LED drivers are sold for lighting applications.

Lighting fixtures often require brightness control, and especially in the case of LED drivers, strict current control is important. Recently, there have been many needs to switch to LEDs for lighting from the viewpoint of promoting energy conservation, as typified by the SDGs, which also require highly efficient lighting.

In addition, LEDs are also being used as indicator lamps in home appliances and automobiles, and LED drivers dedicated to these applications are being developed.

Principle of LED Drivers

LED stands for “Light Emitting Diode” and refers to a semiconductor device that emits light when a forward bias is applied to its PN junction. The LED drivers incorporate a constant-current generation circuit integrated on an IC, and depending on the product, a PWM control circuit, and SPI or I2C interface are also built-in.

In general, the amount of light emitted by an LED varies with the amount of current applied, but the color (emission wavelength) of the LED also changes by the current value. In addition, too much current will have a significant impact on the life of the device. Therefore, it is necessary to accurately control and apply the optimum current value for the LEDs used, taking into consideration the light intensity, hue, and luminous efficiency according to the luminous characteristics of the LEDs, and LED drivers are used for this purpose.

For single-function LED drivers, a combination of discrete Zener diodes, MOSFETs, etc. can be used, but when multiple LEDs are connected in series or parallel and LEDs of various colors with different optimum current values are to be operated in combination, ICs are used to meet the required specifications. 

Other Information on LED Drivers

1. Driver Format of LED Drivers

There are various types of drivers used in LED drivers, such as linear type and step-up/step-down type.

Linear Type
This circuit type does not incorporate a DCDC converter but uses a MOSFET and resistors for constant-current control. The single function allows for miniaturization and cost reduction but has the disadvantage of high MOSFET loss at high input voltages.

Step-Up/Step-Down Type
This circuit type can operate with high efficiency by suppressing the increase in loss during the step-up and step-down functions that can accommodate an increase in the number of LED stages. However, since the circuit is complex and the cost is high, LED drivers that can only support boost or buck are also widely used, depending on the application.

2. PWM Control

PWM control is widely used in LED drivers for dimming. This is because the method of adjusting the driver’s DC current value has problems with heat generation due to lower efficiency and wavelength change (emission color change) accompanying the current change.

In the case of PWM-control led drivers, the apparent voltage can be varied by adjusting the width of rectangular pulses (duty ratio), and there is no power loss associated with dimming. In such a driver, LED dimming is often performed with a semi-fixed resistor. If the semi-fixed resistor is removed and replaced with a volume, LED drivers that can be adjusted with the volume can be realized.

The brightness of LEDs is proportional to the duty cycle of the pulse, but if the ON/OFF cycle is too slow, it can be discerned by the human eye, leading to flickering of the lighting. Therefore, care must be taken with the set frequency of the PWM control.

3. Serial Interface

It is common for several LEDs of different colors to be used in home appliances and automobile instrument panels. Depending on the type and quantity of LEDs to be controlled, IC connection may be difficult if only analog signals for ON/OFF and bias values are exchanged. In such cases, a serial interface with digital control over a few wires, such as SPI or I2C, is used.

LED drivers with serial interface functionality include large-scale products capable of controlling several hundred LEDs simultaneously, as well as products capable of controlling brightness and diagnostics for each channel.