Professional Inkjet Printer The Story Behind the Development of the PIXMA PRO Series

The highest grade of inkjet printer: pursuing the ultimate in beauty and speed

POINT 1

Ink, print heads and mechanisms almost all newly developed

Development specifications that far surpass the high performance of conventional printers

The PIXMA PRO-1, PIXMA PRO-10 and PIXMA PRO-100 were released in 2012, completing the lineup of the new series of professional inkjet printers. The stunning beauty of the photos the printers produce is simply breathtaking. Today, we would like you to tell us about your experiences developing the PIXMA PRO lineup. First of all, what was the development concept?

Nagahara
Generally speaking, there were two concepts. One was to provide even higher image quality than the existing top-of-the-line model. The other was to enable high-speed printing.
Providing a wider color reproduction range, uniform luster across the entire printed surface and smooth gradations are naturally themes that need to be addressed in the pursuit of excellent image quality. Along with these, from the initial stage of development we decided to focus on the image quality of monochrome photos.
Meanwhile, in terms of printing more quickly, in addition to focusing on printing speed, we decided to use a new mechanism that reduces the number of ink tank replacements required.

Hideaki Nagahara

Area of development: Mechanisms

Yazawa
Essentially, we were going for more beautiful images and faster speed than in previous models, but the previous models were nothing to sneeze at. In other words, the development specifications we were aiming for were easier said than done.

If that was the case, you must have had quite an impressive development team.

Yazawa
That's right. And we strengthened it beyond what we had when we developed the previous top-of-the-line model.

Did the popularization of digital SLR cameras lead to a need for high-performance printers?

Yazawa
I think you could say that. We're seeing an increase in users who are very particular about print quality, not only among professional photographers, but also semi-professionals and photo enthusiasts.

Kudo
With the advanced performance now offered by cameras, it's easy to take attractive photos. This means that people want printers capable of producing attractive photo prints. It's a cycle we're seeing.

Nagahara
Although everyone has their own position, I feel that it's our mission to constantly listen to what we're hearing from the market, namely the wish to produce more beautiful prints, and respond to this accordingly.

Preparing for unbelievable levels of improvement

To further raise the already high level of performance, several improvements were made to fundamental inkjet printing technologies and partially new technologies were added. How did you initially feel upon tackling this development project and the various challenges it involved? How about you, Mr. Takayama? You were responsible for ink development, right?

Takayama
I was worried that I would cause problems for everyone again (laughs).

Why do you say that?

Takayama
The better the ink, the harder it is to handle. I needed the teams responsible for the inkjet print heads and controlling image processes to work hard; that was the first thing that crossed my mind. Of course, this is always the case whenever we develop new ink.

Kiyomitsu Kudo

Area of development: Inkjet print heads

Kudo
Good ink is hard to discharge from the print head nozzles. It doesn't fly the way we want it to (laughs). At the same time, when the number of inks increases, it inevitably raises the bar extremely high for achieving uniform printing. This made me think that the level of improvement we'd need was far beyond our previous development efforts.

I see. Did you also sense that ensuring the necessary level of mechanical precision was going to make this a challenging development project?

Nagahara
The specifications we sought for precision greatly surpassed those of previous models. When starting development, targets are generally set one level above previous specifications, so it seemed as though we were aiming to develop something quite unbelievable. With the PRO-1, one theme was equipping the printer with a new ink supply system.

Yazawa
Newly developing almost everything the ink, print heads and mechanisms is uncommon even for a top-of-the-line model. The flip side of this, however, is that we wouldn't have been able to achieve these specifications without going to these lengths. It was a very challenging development project.

Yamamoto
I was responsible for the printing application software, so my concerns differed from those of the others. The thing I had the most trouble with was organizing the requirements for improving usability. You see, professionals use printers in a variety of different ways. This, however, doesn't mean that we can simply add functions to meet every conceivable need. I had trouble deciding which functions to choose.

Well, it seems that each of you in your respective roles clearly anticipated the challenges you would encounter, and then came face to face with these challenges once development began.

POINT 2

Newly developed ink delivers high-quality printing

A new concept: coating with colorless ink

Ink is the direct key to improving the image quality of a printer. What are the characteristics of the inks you developed this time?

Takayama
We didn't improve just the color performance of each ink, but also realized marked improvements in reproducibility and gradation through the combination of inks. When printing in color, even details in dark areas are reproduced, and when printing in monochrome, subtle nuances in dark and light areas are reproduced better than in the past.

Hideki Takayama

Area of development: Inks

What did you do to achieve this?

Takayama
Theoretically speaking, the three primary colors are sufficient for color printing. When pursuing image quality, however, those three theoretical colors aren't enough. That's why the PRO-1 and PRO-10 use six colors of ink and the PRO-100 uses five colors. This makes possible an expanded color gamut, especially in dark areas. But at the same time, it's necessary to increase the number of black inks to improve gradation for monochrome printing. With the PRO-1, the number has been increased from the original three to five. The PRO-10 and PRO-100 are equipped with three black inks.
Using the best quality ink currently available, we worked repeatedly with the Image Processing Group, evaluating image quality from the perspectives of both machine-measured data and human visual perception to determine the number of colors of ink that are needed when printing in color and in monochrome.

A transparent ink called Chroma Optimizer was used for the first time in the PRO-1 and the PRO-10. What does it do?

Takayama
The pigment inks used in the PRO-1 and the PRO-10 offer powerful printing results, like what you'd see in a painting, but dye inks realize better luster. We newly developed Chroma Optimizer to achieve greater gloss with pigment inks. It coats the ink droplets on the surface of the paper. This not only increases the glossiness, but also improves the depth of black by suppressing the diffused reflection of light.

Kudo
To achieve this effect, the Chroma Optimizer must be properly ejected from the nozzles and coat the colored ink uniformly. But you have to keep in mind that we were dealing with an "invisible man" (laughs). We had a lot of trouble with verification and evaluation.

Yazawa
The use of Chroma Optimizer meant that we needed to carry out development based on a new concept even in terms of controlling image quality, which gave us a hard time.

Takayama
But the difficulties encountered in the development of the pigment inks were nothing like that (laughs). Orders flew back and forth between each group. Every day we'd repeat a process of trial and error.

I see. Compared to that, how did things go during the development of the inks for the PRO-100, which uses eight colors of dye ink?

Takayama
The dye inks for the PRO-100 have been significantly improved for better coloring performance, resistance to the elements and transparency. We didn't cut any corners (laughs).

Yazawa
The PRO-1 offers the highest level of performance specs while the PRO-10, as an affordable pigment ink printer, is next in terms of the color gamut it realizes, and then there's the PRO-100, a dye-ink printer for users particular about image quality that offers excellent transparency and gloss. Through the PIXMA PRO lineup, we'd like to provide photographers with a wide selection of choices to satisfy their ever-growing range of needs.

Controlling ink bubbles in real time

Now that the subject of print heads has come up, I'd like to ask you some questions Mr. Kudo. The number of nozzles used in the PRO-1 is 1.6 times the number of the previous model. Was that to increase printing speed?

Kudo
That's right. It's approximately 1.8 times faster. Since the nozzle diameter is the same, it was necessary to keep the dots uniform in accordance with the increased length of the print head.

As for ensuring this uniformity, there's no way to avoid a temperature response with regard to the principle of ejecting ink through the formation of bubbles, right?

Kudo
That's right. When printing, the size of the bubbles increases as the temperature of the print head rises and, as a result, printing quality deteriorates. That's why we introduced a method enabling real-time control. The system responds to changes in the temperature of the print head during printing and constantly adjusts the energy used to discharge the ink from the nozzle.

Overview of real-time drive control

Yazawa
In previous models, control of the temperature response was only carried out when the print head reversed direction at the left and right edges. But this time around we realized that high image quality required that we control it in real time.

Kudo
For a printer to achieve high image quality, the ink and the print head need to advance hand in hand. As such, to ensure optimal performance of the print head, we correct the control value on each PRO-1 when it's shipped.

Determining the optimal combination of inks and placement of ink droplets on the paper surface for each condition

If you're able to achieve the uniform ejection of quality ink from the print head, next would be controlling image quality. What were you able to improve the most this time?

Yazawa
We established a method for determining the optimal combination of inks and placement of ink droplets on the paper surface, which we applied across the entire PIXMA PRO lineup. We call it the OIG System and it controls image quality by determining optimal settings for ink ejection with regard to when (ink should be ejected), which inks (should be used), where (ink droplets should be placed on the surface of the paper), and how much should be ejected for each paper type.

Conceptual diagram of the OIG System

The combinations of the number of inks selected and the percentages of each color are countless. Wasn't finding the right answer a difficult problem?

Yazawa
Yes, it was. We felt that we needed to adopt a more systematic approach than in the past, but the development of this system itself was actually quite challenging. We made it possible to ascertain numerical values for image elements such as color performance, tonal gradation, glossiness and black density, after which we created an enormous database by measuring actual print results. The system is based upon this analysis.

I see. But now that you can use the OIG System, it must be easier to support changes in ink under development.

Yazawa
Exactly. We've improved the development efficiency of image quality control and evaluating image quality has become more objective.

POINT 3

Usability improved and mechanical precision enhanced

A new ink supply system poses countless technical issues

I assume that paper feed precision would naturally be an issue in improving image quality in the development of this system?

Nagahara
The precision of the feed mechanism in previous models had already reached a considerably high level, but we worked to improve it further. We managed to reduce errors that occur in a single print feed to just a few microns.

How did you do that?

Nagahara
We redesigned and tested each individual area where precision seemed to be relatively lax and repeated this process over and over. For example, it helps to have a paper guide that firmly holds the paper on both sides during the paper-feed process, but paper-feed accuracy improves if the paper guide is not in contact with the paper during printing. So, I thought we should experiment with a variety of paper types. That's what it was like. We also improved the overall rigidity of the feed mechanism by thoroughly eliminating the flexure, offset and other issues that occur on the roller.

The PRO-1 incorporates an off-carriage ink tank system that utilizes a tubular ink supply system from fixed ink tanks, a first for Canon inkjet printers. What benefits does this provide for users?

Nagahara
The ink tanks need to be changed less frequently. Since the tanks aren't attached to the print head, we were able to provide them with greater capacity. Under the same conditions, it's now possible to print 2.5 times more than before.

Off-carriage ink tank system

The tubular ink supply system was developed completely from scratch. Did you face any issues during development?

Nagahara
Yes, there were many issues (laughs). First, we had to repeatedly conduct tests, beginning with the selection of the tube material. It had to be neither too hard nor too soft, and not allow any moisture in the ink to evaporate. Also, the hardness of the material affects print head movement.

I see. So when doing something for the first time, you need to begin by considering which type of material to use.

Nagahara
The next problem we faced was that the mechanism would become quite heavy when using a set of 12 tubes containing ink. The movement of the tubes causes the print head to vibrate.

Kudo
The pressure placed on the ink within the tubes can change when the tubes move around, which can affect the ink discharge from the nozzle.

Nagahara
We addressed each problem caused by the free movement of the tubes through such steps as using a structure to offset vibration and changing the tube length and retention method.
To fill the tubes with ink, the tubular ink supply system also required mechanisms to apply pressure on the tank side and provide suction on the print head side. Despite its simple appearance, the system presented many technological issues.

Updated print configuration software based on interviews with photographers

No matter how good a machine is, its value drops if it's too difficult to use. In this way, the Print Studio Pro printing application software developed by Mr. Yamamoto's group plays an important role. Could you tell us about it?

Yamamoto
Once installed on a computer, users can easily configure the printer for printing out photographs retouched using image editing software. As more than six years have passed since the original version of the software was released, we reexamined users' needs and developed the software anew so that it can be used across all PIXMA PRO models.

Tsuyoshi Yamamoto

Area of development: Application software

What are the most distinguishing characteristics of this development?

Print Studio Pro

Yamamoto
We placed emphasis on the user interface and enabled all configurations to be carried out on a single screen.

I understand that you also conducted numerous interviews with photographers during development.

Yamamoto
Yes, we learned a variety of things. For example, we found out that a user's configuration content and procedures can differ depending on the editing software and operating system, and we were asked to do things in a certain way. We organized all of the feedback we received and spent time considering to what extent they should be reflected in the software.

I see. What sort of user feedback left the strongest impression?

Yamamoto
For example, one user said, "Professional photographers pay so much attention to color that we work in rooms with only white walls when making color adjustments to photos. Therefore, it would be nice if consideration was given to the color of the frames and backgrounds used in printing applications." In response, we use gray-based frames in the new software.

I'm not surprised that professional photographers have such pointed feedback.

Yamamoto
It was very interesting to hear from the point of view of professional photographers, who notice even the slightest deviation in color. During these interviews, I recall thinking that I wanted to make software that would bring out the best of their creativity.

POINT 4

Numerous difficulties overcome through collaboration between development teams

Collaboration between strong teams, accumulation of technological knowledge

What do you think was the greatest factor in achieving development success?

Nagahara
Each team was able to cooperate without getting obsessive about their respective technological areas or territories. I think having low barriers between teams was the main factor that led to success. What do you think?

Takayama
I agree. In order to make the best product possible, we often worked together with the print head group and image processing group. We took every opportunity to meet, regardless of regularly scheduled meetings. I think this greatly helped the ink development team.

Kudo
Because there were so many issues to address, you could say that we had to talk to each other a lot (laughs). However, having more opportunities to talk also meant we had clashes of conflicting opinions. At such times, I believe that a factor in our success was everyone's strong approach toward pursuing a common goal.

Nagahara
In addition to such collaboration between horizontally aligned teams, the cooperative relationship between vertically aligned teams was also very close during this project. The production division also got involved at a relatively early stage, which enabled us to revise the course of design with an eye to mass production.

It seems that Canon's culture of promoting collaboration between teams worked even better than usual. Now, what about the technology itself?

Yazawa
Canon has frontline products that range from image input devices such as cameras and scanners, to output devices, including laser printers and inkjet printers. The company also has a long history of making copying machines that perform both input and output operations. I particularly felt that Canon's accumulated technologies across such a wide range of imaging products was an underlying strength in this case. Deep technological knowledge really pays off when a problem arises.

Takeshi Yazawa

Area of development: Image processing

Kudo
I must admit that I felt the same way. This strength doesn't simply come from handling many products, but from developing most products in-house, enabling the company to pool technological knowledge and apply it to new development.

Yamamoto
If you think of knowledge as opinions, these are pooled not only within the company, but also across our affiliates. By getting feedback from salespeople at our marketing subsidiaries who are in charge of photo enthusiasts, we were able to hear many useful opinions. Another strength of Canon's product development is being able to quickly utilize these types of valuable resources.

Bringing the joy of creativity to both professionals and amateur users

I think the PRO-1 is the best consumer inkjet printer currently on the market. How would you like it to be received by the users?

Takayama
While this doesn't only apply to the PRO-1, I would be happy if we could instill the mentality among users that they can't go wrong if they choose a PIXMA PRO-line printer.

Nagahara
That's exactly right. However, I genuinely hope that people will enjoy making the most of this series by creating greater quality prints. I'm confident that users will be able to print photographs that are much higher in quality than in the past, and that even professionals will be pleased with what they see. In particular, I think the image quality of monochrome photos will leave them amazed.

Yamamoto
Only Canon can provide a comprehensive solution that begins with the EOS series of digital SLR cameras, includes Digital Photo Professional image editing software and Print Studio Pro printing configuration software, and concludes with output using the PIXMA PRO line of printers. I hope that professional photographers will realize greater efficiency in their work and that entry-level photographers can improve their skills.

What are your thoughts regarding the development of the PRO Series?

Nagahara
I would like to see the high-image-quality printing technologies that we developed be simplified and reduced in cost so that they could also be used in general consumer models.

Yazawa
I'm more interested in professional-use models. I would like the lineup to achieve a level of image quality that would please even professionals who are loyal to silver-halide photography. At the same time, I would like to pioneer a new world of printing possibilities enabled by inkjet printers.

So, I guess you could say that the goal you just reached is the starting point for your next endeavor. Thank you for your time today.

Closing comment
When speaking with the five engineers involved in this project, I saw glimpses of how they enjoyed facing the various challenges that arose. I wonder if this mentality is part of an engineer's spirit, or if it stems from the pride felt by watching Canon products evolve. Whatever the case, I would like to hear from them again when they finish developing their next new products.

Interview & composition
Tadahiro Suda
Born in Fukushima prefecture in 1955. Became a freelance writer in 1990 after working as an editor at a news service and publisher, and managing an editing production agency. He is active in a wide range of publications, including management information journals and job-transfer publications. In recent years, he has contributed many articles to media portal sites, with the development of technology and products as one of his main areas of focus.

Developers interviewed

Hideaki Nagahara

Area of development:
Mechanisms

Kiyomitsu Kudo

Area of development:
Inkjet print heads

Hideki Takayama

Area of development:
Inks

Takeshi Yazawa

Area of development:
Image processing

Tsuyoshi Yamamoto

Area of development:
Application software

Previous Interviews

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