The Frontiers of Science

Kōshinsha—At the Forefront of “Extreme Counting” Technology

Science Technology Society Lifestyle

Kōshinsha is a Kyoto-based manufacturer of highly accurate counting devices called Digital Area Counters. Here we look at how the company is bringing innovative technology solutions to the most challenging counting tasks.

A Digital Area Counter (DAC) used for counting small objects; the device consists of a simple conveyor unit and a photosensor.

Watching Kōshinsha Co., Ltd.’s Digital Area Counter in action is fascinating. Screws scattered on a tray are separated into rows and then drop into a box. As they are falling, the DAC counts each screw and displays the climbing number on a screen. The screws are not arranged in neat lines, and there is little to make one think that any counting is being done—yet the results are incredibly accurate.

A DAC is capable of counting a vast array of objects, whether industrial parts such as nuts and bolts, small screws, ball bearings, electronic parts, connectors, and clothing buttons, or such items as diced vegetables, meatballs, fried chicken, or plant seeds. The device is used in a wide range of fields, most of which involve individual objects that are difficult to count using other devices.

Line Sensor Tracks Shadows Cast by Objects

Creating a machine capable of counting objects is no easy task. Any variation in the shape or weight of an object can result in an incorrect measurement by the photosensor or scale used. But such hard-to-measure items can be accurately counted by a DAC, thanks to the line-sensor technology developed by Kōshinsha.

Objects of the same weight and of variable weights.

Generally, photosensors only monitor one spot. In contrast, a DAC uses a line sensor to scan the shadows cast by an object at a frequency of 10,000 times per second. This makes it possible to even accurately count objects that have holes, such as a nut.

Example of how the sensor monitors the shadow cast by an object.

Mechanism that enables counting of objects with holes

Since a DAC counts an object and measures its area at the same time, small foreign objects that happen to be mixed in can be excluded. This also makes it possible to separately count two different objects that overlap each other. This patented Kōshinsha measuring technology has many advantages. In addition to simultaneously counting objects in multiple rows using a single sensor, the device is not easily affected by water, oil, or dust because the sensor is separated from the objects counted. Moreover, unlike most photosensors, a DAC can even count very small objects.

Line sensors also measure the area of an object.

20 Years of Trial and Error

Shirakawa Mitsuhide, executive director of Kōshinsha.

“It might seem that our technology would be easy to imitate,” notes Shirakawa Mitsuhide, the executive director of Kōshinsha. “But in fact, an array of expertise is necessary to count objects accurately, including the design of the conveyor unit. For example, conveying things like frozen bread dough so that it doesn’t stick together is a challenge. Our strength is the experience we have built up, through trial and error, over the past two decades of producing counting machines.”

“We constantly receive inquiries from companies in Japan and elsewhere asking whether we can count a particular sort of item. Metal auto parts, to take one example, can be difficult to measure because of their complex shapes and crevices, plus the fact that the oil used to lubricate them can alter their weight. Our customers are often overjoyed when they discover that we can accurately count such difficult items using a DAC. I recall one customer telling me that for many years he had thought a certain auto part simply could not be counted. In another case, a drug company brought in a sample of 5 million tablets in a drum for a performance test, and purchased our machine after we demonstrated that it could count the tablets without making a single mistake.”

In Touch with Current Market Needs

Sales of Kōshinsha counting machines have grown rapidly in recent years thanks, in part, to the ongoing optimization of supply chains and spread of on-demand production systems. Many manufacturing companies today produce things only in the necessary amounts, and only when needed, in order to reduce unnecessary inventory and to adjust to abrupt changes in demand. This shift toward optimization of production has led the delivery unit to change from “weight” to “number of pieces.”

The development and spread of frozen storage technologies and convenience stores has also raised the need for devices to count such items as frozen bread dough—and many Kōshinsha devices are used for such counting. Convenience stores make small changes in order quantities based on the predicted demand for the day at a given store. Bread-producing plants can adjust to these constantly fluctuating orders by accurately counting the units of frozen bread dough prior to fermentation, using a counting device.

Businesses that make the boxed lunches so common in Japan also have a high degree of need for counting devices so that the appropriate number of vegetables and other items can be placed in each box lunch. Another area of increasing global demand these days is the counting of plant seeds. In the past, seeds were sold by unit weight or volume, but increasingly the number of seeds is becoming the unit. This is the result of technical innovations and changes in the industry. Now that technology makes it possible for seeds to germinate with near certainty, losses due to counting errors are no longer acceptable in the case of such expensive, high value-added seeds. For some 20 years already in Japan, seed number has been the unit for counting and now this trend is spreading to other countries as well.

Kōshinsha’s seed-counting machine has been the focus of global attention.

But Shirakawa recalls a time when counting machines were not selling so well: “At that time, an acquaintance told me that the only way the business would succeed is if we work at it tirelessly for the next 20 years or make a massive investment.” But, as a result of indeed keeping at it for two decades, the technology of Kōshinsha has come into its own. And along with that improved performance, more favorable market conditions have also come into existence.

Current technology is making it possible to develop devices capable of counting different items in multiple, random rows by sorting them according to color, shape, or dimension—at a rate of 3,000 items per minute (left). The pink outlined items are set aside from the other items counted (right).

(Originally written in Japanese by Kimura Ryōji.) Kyoto science technology frontier Kōshinsha numbers counting machines company