Editing Omron B3K series

{{Infobox dswitch
| image name        = Logitech Romer-G.jpg
| manufacturer      = [[Omron]]
| product code      = 
| product name      = Logitech Romer-G,<br/>Das Keyboard Gamma Zulu,<br/>Creative Labs PRES
| introduced        = 2014
| sense method      = [[Metal contact]]
| switch mount      = [[Switch_mount#Plate_mount|Plate mount]]
| switch type       = Tactile, Linear
| pretravel         = 1.5 mm
| travel            = 3.0, 3.2 or 3.5 mm
| actuation force   = 45 g
| lifetime          = 70 - 100M
| family            = 
| patents           = [https://www.google.com/patents/US20150043192 US20150043192] (2014)<br>(also as CN104347295A, CN204011170U, EP2835808A1)
| inventor          = Yasuhiro Tanoue, Mamiko Naka, Kazuhira Izawa, Masayuki Shinohara
}}

Omron '''B3K''' is a series are mechanical keyboard switches designed for [[backlighting]].
Switches have been released in branded variants as '''Romer-G''' for [[Logitech]], '''Gamma Zulu''' for [[Das Keyboard]] and '''PRES''' for [[Creative Labs]].

==Description==
B3K switches facilitate LED [[Backlit keyboard|backlighting]] via a light pipe leading to a surface-mounted LED. The design is said to focus the light more evenly through the legends on the [[keycap]] and minimise light leakage<ref name="romerg3" />. The patents describe various approaches to achieving the illumination, illustrated with light intensity plots.

The slider has four corner posts. Two of these each holds a sliding ramp, each holding one pair of metal contacts apart.
The slider is supported by a large spring, which sits around the centre light guide.
The switch provides redundant sensing in an SPST arrangement by using a pair of identical terminals, each bearing a stationary contact and a movable contact.
The two lateral ends of each terminals are at 90° to each other, and collectively the terminals occupy all four sides within the switch, with the movable contact at one end of each terminal meeting the stationary contact at the opposite end of the other terminal.

Similar to [[Cherry MX]], tactile variants have a bump on the sliding ramps.
The patent depicts the tactile "pressing rib" design but does not explain the shape or mention tactility.
The tactile variants have been compared in feel to the [[Cherry MX Brown]] switch by those who have tried it.<ref name="DT-review" /><ref name="GH-review" />

==Variants==
===Romer-G===
Logitech Romer-G exist in both tactile damped (B3K-T13L), tactile ((B3K-T13L2) and a linear variant (B3K-L13L).
The top housing bears the Logitech "G" logo on two opposite sides, and the Omron logo on a third side. The bottom housing bears the part number.

The earliest variant was the tactile damped B3K-T13L, which can also be identified by having a blue housing whereas the others are black.
[[Damping]] is on both the down-stroke and up-stroke, by having a pair of plastic prongs on the slider (called "elastic touch piece" in the patent). These collide with features of the base (downstroke) and lid (upstroke) to absorb impacts. Specifically, the prong hits a raised area in the base on the way down, and ridges in the lid on the way up. The patent describes the product as a "silent type switch having small operation sound and return sound".
The key travel for the damped switches is rated at 3.0 mm, but has been measured to between 3.06 and 3.17 mm in reality.

The Romer-G variants with black top housing (B3K-T13L2, B3K-L13L) lack the damping prongs, and have instead more key travel: rated at 3.2 mm.

Logitech had applied for the "ROMER G" trademark on 23rd June 2014.<ref name="romerg2" />

===Das Keyboard Gamma-Zulu===
The Das Keyboard Gamma-Zulu (B3K-T135M) are tactile and undamped with 3.5 mm key travel. The top housing is black, carrying the Omron logo and the Das Keyboard symbol on different sides.

They were manufactured by Omron for Das Keyboard ([[Metadot]]), starting with the [[Das Keyboard#Das Keyboard 5Q|Das Keyboard 5Q]] which was announced on a Kickstarter page in July 2016 with estimated delivery in Dec 2016.<ref name="das5qkickstarter">Kickstarter &mdash; [https://www.kickstarter.com/projects/1229573443/das-keyboard-5q-the-cloud-connected-keyboard/description Das Keyboard 5Q: The Cloud Connected Keyboard by Das Keyboard]. Retrieved 2016-07-02.</ref>
When announced, the estimated lifetime of the switch has also been upped to 100 million actuations, compared to 70 million for the first Romer-G.

===Creative Labs PRES===
Creative PRES switches (''Perceive-React-Execute Switches'') <!-- :rolleyes: -->
were introduced with the ''Sound BlasterX Vanguard K08'' keyboard. 

===Observed variants===
All variants have officially a pre-travel of 1.5 mm.

{| class="wikitable variants-table"
! !!Brand Name!!Part #!!Colour<br>(Top/Slider)!!Type!!Total Travel!!Actuation force!!Tactile force!!Total force!!Rated lifetime
|-
|[[File:Logitech Romer-G blue -- variants table.jpg|175px]]
| rowspan="3" |Logitech Romer-G
|B3K-T13L||Blue/Clear||Tactile Damped||3.0 mm
| rowspan="3" |45 gf
| || ||70 M
|-
|[[File:Logitech Romer-G black -- variants table.jpg|175px]]||B3K-T13L2||Black/Clear||Tactile||3.2 mm||55 gf|| ||
|-
| ||B3K-L13L||Black/Grey||Linear||3.2 mm|| || ||
|-
| ||Das Keyboard Gamma-Zulu||B3K-T135M||Black/Clear||Tactile||3.5 mm||45 gf||55 gf||80 gf||100 M
|-
| ||Creative Labs PRES|| ||Transp/Clear||Tactile||3.5 mm|| || || ||70M
|}

==Gallery==
<gallery widths="250" heights="187">
File:Logitech Romer-G -- branding comparison.jpg | Branding comparison: black has a revised Logitech logo
</gallery>

===Blue Logitech Romer-G (B3K-T13L)===
<gallery widths="250" heights="187">
File:Logitech Romer-G -- top.jpg                        | Top; the Logitech "G" logo is just about visible
File:Logitech Romer-G -- bottom.jpg                     | Bottom, showing the base of the light guide
File:Logitech Romer-G -- LED chamber.jpg                | SMD LED chamber between the light guide and the PCB
File:Logitech Romer-G -- G branding.jpg                 | Switch angled towards the light to catch a reflection of the branding
File:Logitech Romer-G -- light guide demonstration.jpg  | Demonstration of the SMD LED light guide
File:Logitech Romer-G -- part number.jpg                | Omron part number (B3K-T13L) and what is presumably the batch number (217 5C4) on the side of the switch
File:Logitech Romer-G -- opened.jpg                     | Opened
File:Logitech Romer-G -- spring removed.jpg             | Spring removed; the upstroke damping stop can be seen on the inside of the lid
File:Logitech Romer-G -- redundant contacts.jpg         | Redundant contacts
File:Logitech Romer-G -- contacts.jpg                   | Two identical terminals which achieve redundant sensing using two pairs of contacts, one movable and one stationary per terminal
File:Logitech Romer-G -- slider.jpg                     | Slider; the elastic touch piece and tactile ramp on one side can be seen
File:Logitech Romer-G -- two actuator ramp shapes.jpg   | Opposite corner contact actuator ramps are different shapes
File:Logitech Romer-G -- disassembled, top views.jpg    | Disassembled, top views of components
File:Logitech Romer-G -- disassembled, bottom views.jpg | Disassembled, bottom views of components
</gallery>

===Black Logitech Romer-G (B3K-T13L2)===
<gallery widths="250" heights="187">
File:Logitech Romer-G black -- branding.jpg    | Logitech and Omron branding; blue also has an Omron logo
File:Logitech Romer-G black -- part number.jpg | Part number: B3K-T13L'''2'''
</gallery>

=== Gamma Zulu ===
<gallery widths="250" heights="187">
File:Gamma Zulu complete.jpg|alt=Assembled switch showing the Omron brand and keycap mount|Exterior view of Omron Gamma Zulu
File:Internal mechanism Gamma Zulu.jpg|alt=Switch body with slider and top cover removed|Spring, light pipe and switch contacts of Omron Gamma Zulu
</gallery><br />
==Keyboards==
The first keyboard with B3K switches was the Logitech G910 Orion Spark, announced in September, 2014.<ref name="romerg1" />

===Full-size===

*[[Logitech G613 Wireless Mechanical Keyboard]]
*[[Logitech G910 Orion Spectrum]]
*[[Logitech G910 Orion Spark]]
*[[Logitech G810 Orion Spectrum]]
*[[Logitech G413 Carbon & Silver]]

*[[Das_Keyboard#Das_Keyboard_5Q|Das Keyboard 5Q]]

*[[Sound BlasterX Vanguard K08]]

===Tenkeyless===

*[[Logitech G PRO]]
*[[Logitech G410 Atlas Spectrum]]
*[[Logitech G310 Atlas Dawn]]

==References==
<references>
<ref name="romerg1">NAG Online — [http://www.nag.co.za/2014/09/17/logitech-announces-the-g910-oriongaming-keyboard/ Logitech announces the G910 Orion gaming keyboard | NAG Online] Dated 2014-09-17. Retrieved 2015-08-01.</ref>
<ref name="romerg2">inovia.com — [http://www.inovia.com/products/directory/trademarks-number-86317070/romer-g-trademark-owned-by-logitech-international-s-a inovia | U.S. trademark search and registration] Retrieved 2015-08-01.</ref>
<ref name="romerg3">Logitech — [http://gaming.logitech.com/en-us/articles/romer-g Romer-G] Retrieved 2015-08-01.</ref>
<ref name="DT-review">Deskthority — [http://deskthority.net/review-f45/logitech-g910-orion-spark-t9232.html {{sq|Reviews}} Logitech G910 Orion Spark] Posted 2014-11-25. Retrieved 2015-08-01.</ref>
<ref name="GH-review">Geekhack — [https://geekhack.org/index.php?topic=65026.0 Logitech G910 Orion Spark - mini review] Posted 2014-10-31. Retrieved 2015-08-01.</ref>
</references>

[[Category:Omron switches]]
[[Category:Tactile switches]]
[[Category:Linear switches]]
[[Category:Metal contact switches]]
[[Category:Production switches]]
[[Category:RGB switches]]
[[Category:Damped switches]]
[[Category:Illuminated switches]]
[[Category:List of all keyboard switches]]