Thursday, October 25, 2012

It's Been a Year!

I was surprised to discover I made my first print with the 7900 one year ago today. This blog was a year old yesterday. Thanks to all who have visited the blog and to those who have commented. Most have done that via direct email, so we're not seeing many comments attached to individual postings here.

According to the printer's log, I've printed 534 "pages". Not really a useful statistic. 146 of those pages were nozzle check prints. I suppose it's possible I've made nearly 400 real prints in the past year, but that seems a rather high number.

C, O, Y, LC, MK, PK, VM, and G are still the 90ml "starter" ink cartridges. Except for MK, which I seldom use for my own work, all have displayed "1%" for some time, and all have been temporarily replaced more than once to allow cleanings. LK was the first of the starter inks to be replaced. The original maintenance cartridge is at 36%.

My apologies for the lack of postings lately. I've been traveling, having spent time recently in Ohio and Michigan. Fall color was a bit dull in Ohio, but much nicer in west-central Michigan. I spent several days there photographing in the rain. A little uncomfortable now and then, but the wet conditions were often very nice for shooting fall color in the hardwood and pine forests.

I returned to find several new print jobs waiting for me, in addition to a small commission of my own work I'd lined up before leaving for the east. One of the new jobs is reproducing a large, 40-year-old etching. I'll be printing this on Epson Hot Press Natural, a mat-finished paper I've  been wanting to try for a while. Now that I think about it, I'd best get that paper ordered!

  --Jay

Saturday, October 6, 2012

Driver Update 9.04 (Macintosh)


On 6 September Epson posted to their US support site an update to the Mac driver for the 7900. This takes the driver from version 8.68 to 9.04. About this update, Epson says, "This file corrects a possible issue when printing borderless retain size." The release notes also indicate this update is for OS X 10.5 through 10.8. The download page includes installation instructions, pretty standard fare. There's no mention of a requirement to uninstall the previous driver, so I didn't. After installing the update and checking the version, I see this:


This is similar to what I saw after my update from 8.66 to 8.68. My original installation of the printer, back in October, 2011, was with the 8.65 driver.

Interestingly, when I open the Mac's Print & Fax preferences (control panel), click the Options & Supplies... button, the General tab of the resulting dialog still shows the driver version as 8.68.

I've no idea why. I made several prints yesterday and saw no differences in the driver's options or set-up choices. One would expect a full point (from 8.something to 9.something) to have some enhancements or new features rather that only bug-fixes. Of course, Epson does things its own way, and not with any great consistency.

There's one more place, as far as I know, where OS X exposes the driver version. That's in the Printers sheet under Hardware, in the System Profiler. The driver is shown there as 8.6.8.

I've built a Mountain Lion (OS X 10.8) drive for my Mac Pro. When time permits (not real soon, alas) I'll install the new driver on that system. Since it won't be an update installed over an older version. I'd expect the version number to appear correctly in all places. TBD.

  --Jay

Thursday, October 4, 2012

Anatomy of a 7900/9900 Ink Cartridge

If you've never wondered what's inside an ink cartridge (besides ink), that's probably because you have a normal brain and worthwhile things to do with your life. I, on the other hand.... Sometimes it's useful to know how or why things work. Sometimes not. Either way, it's often interesting. I can't resist taking things apart.

What follows is a series of photos of the parts inside my spent, 90ml "starter" cartridge of light magenta ink. While I have some hunches about the purpose of the various pieces, I've no direct knowledge from Epson. Best I can do is guess what some of these things do.

This view shows the cartridge after I snapped off the cover. The front "handle" end of the cartridge is at the bottom of the picture. There's a transparent film seal (which I removed before taking this picture) covering the compartment housing the ink bladder (the silver bag with the bar code). That seal allows the cartridge to be pressurized by the printer through the nipple at the bottom-rear of the cartridge. I replaced this cartridge when the 7900 stopped printing and required a new one. It's clear the machine squeezed every last bit of ink from the bag. It's completely flat, with no pockets of wasted ink. Nice!


The rear of the cartridge. The CSIC chip (Customer-Specified Integrated Circuit, a micro-controller made to Epson's specifications) is at the top. Below that is a component with a small ink reservoir, the valve through which ink exits the cartridge, and a pair of conductors that make contact with pads on the underside of the CSIC chip. The nine gold pads on top of the CSIC chip communicate cartridge status to the printer.

 This complex gadget includes a small reservoir through which ink flows from the bag to the exit valve that mates with the nipples in the back of the printer's ink bays. The nipple at far left fits into the ink bag in the cartridge.

There's a chip, or perhaps a piezo element, between the two metal tabs behind the small reservoir. My guess is that this either counts pulses from the small, spring-loaded "paddle" that covers the reservoir (not shown), or directly measures or senses the presence of ink in the reservoir. In any case, the count or sensed input is communicated via the metal tabs to the CSIC chip shown in the next image.

The CSIC chip, showing the chip-on-board construction. The two gold pads, showing slight wear marks in their centers, make contact with the metal conductors running to the top of the part in the previous two pictures. This board has nine gold pads on the opposite side. I assume there are matching contacts for at least some of those pads in the printer's ink bays, so information from the chip can be communicated to the printer.
That's the best I can do with my technical guess-work. Perhaps someone more knowledgeable can chime in with descriptions of what these parts really do, and perhaps provide proper names for the various components.

Clearly, when one buys a cartridge (currently I'm paying about $85 for 150ml carts) one is getting much more than ink.

  --Jay