The field of the invention is key switches for keyboards.
The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided in this application is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Early keyboards were known, in part, for the sound the keys made when pressed. The recognizable clicking was the result of each key being configured as an actual physical switch that, when actuated, resulted in creating an electrical signal or closing/opening a circuit that a computer interpreted as a key press. Because these early keyboards used mechanical switching, they had a distinct feel associated with the force required for each key to register a keypress. As keyboards evolved, newer technology began to replace these old mechanical keyboards, resulting in the loss of the look and feel of the original mechanical keyboards.
One technology that reduced keyboard cost and helped moved the industry away from mechanical keyboards was the membrane switch. With membrane switches, keyboards could be lower profile, have keys that could be actuated with less force and less travel, and they were much cheaper. But computing—and especially gaming—enthusiasts have often preferred the feel and sound of a mechanical keyboard, not to mention the reliability. Now, more than just enthusiasts choose mechanical keyboards. Today, an entire industry exists to serve these once-niche groups. But mechanical keyboards remain more expensive than membrane switch-based keyboards, and because membrane switches are more prone to wear and tear, a mechanical key switch that actuates a membrane switch must isolate the force of a key press from transferring to the membrane. A need has therefor arisen for a membrane switch-based keyboard having the sound, feel, and reliability of a mechanical keyboard.
Some efforts have been made to improve key switches, but these all fall short in accurately replicating the feel of a mechanical key switch while benefiting from the use of inexpensive membrane switches. For example, International Application WO2019196611A1 discloses a keyboard with a mechanical key switch with an associated membrane. The '611 Application features a shaft disposed within a plunger, where the shaft is coupled with the plunger by a spring, thus separating the force of a user's key press from directly impacting the membrane switch. Although this application does control some of the force that is applied to the membrane switch, its configuration does not fully isolate the force of a user's key press from the membrane, resulting in force applied to the membrane from being inconsistent, which results in unnecessary wear and tear. The '611 Application thus discloses a key switch that does not allow for precise control over how much pressure is applied to the membrane, and is incapable of causing the same force to be applied regardless of how hard or fast a user presses a key.
This and all other extrinsic materials discussed in this application are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided in this application, the definition of that term provided in this application applies and the definition of that term in the reference does not apply.
It has yet to be appreciated that key switches can be designed to benefit from membrane switching without sacrificing reliability, feel, or sound that are hallmark of true mechanical key switches. Thus, there is still a need in the art for improved key switches.
The present invention includes systems and methods directed to key switches for use in keyboards. In one aspect of the inventive subject matter, a key switch is contemplated to include: a lower casing having an actuator hole through a bottom surface; an upper casing having a plunger hole through a top surface and configured to couple with the lower casing to form an interior space; a plunger comprising a sloped surface, wherein the plunger movably couples with the lower casing; and a rocker disposed within the interior space. The rocker includes a first pivot point and a second pivot point, where the first pivot point couples with a first side of the lower casing and the second pivot point couples with a second side of the lower casing. The rocker also includes a hammer disposed on a first portion of the rocker and an actuator disposed on a second portion of the rocker, where the first portion of the rocker exists on a first side of the first and second pivot points and the second portion of the rocker exists on a second side of the first and second pivot points. The key switch also includes a spring disposed between the lower casing and the rocker, where the spring is configured to press the hammer against the sloped surface. The rocker and the plunger are configured such that, upon depressing the plunger at least partially into the interior space, the rocker is configured to rotate about the first and second pivot points based on the hammer sliding along the sloped surface.
In some embodiments, the actuator extends through the actuator hole upon depressing the plunger. The actuator can thus be configured to, upon extending through the actuator hole, contact a membrane switch disposed below the key switch. In some embodiments, the plunger comprises an upper portion having a cross-shaped cross section to facilitate coupling a key cap thereto. In some embodiments, the plunger features a piston and the lower casing features a corresponding piston cavity. The piston in such embodiments is configured to fit at least partially within the piston cavity such that the piston cavity acts as a guide for the piston's movement, ensuring that went a user presses a key, the key travels up and down along an intended movement path. In some embodiments, the key switch also includes a second spring disposed between the lower casing and the plunger, where the piston and the piston cavity are disposed within an interior portion of the second spring.
In another aspect of the inventive subject matter, a key switch is contemplated to include: a casing having an actuator hole through a bottom surface; a plunger comprising a sloped surface, where the plunger movably couples with the casing; and a rocker at least partially disposed within the casing. The rocker includes a hammer disposed on a first portion of the rocker and an actuator disposed on a second portion of the rocker, and a spring is disposed between the casing and the rocker. The spring is configured to press the hammer against the sloped surface, and, upon depressing the plunger at least partially into the interior space, the rocker is configured to rotate based on an interaction of the hammer with the sloped surface.
In some embodiments, the actuator extends through the actuator hole upon depressing the plunger, and the actuator is configured to, upon extending through the actuator hole, contact a membrane switch disposed below the key switch. The plunger can include an upper portion having a cross-shaped cross section to facilitate coupling a key cap thereto. In some embodiments, the plunger also includes a piston and the casing features a piston cavity, where the piston is configured to fit at least partially within the piston cavity such that the piston cavity acts as a guide for the piston's movement. In some embodiments, the key switch also includes a second spring disposed between the casing and the plunger, where the piston and the piston cavity are disposed at least partially in an interior portion of the second spring.
Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
The following discussion provides example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
As used in the description in this application and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description in this application, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
Also, as used in this application, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously.
In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, and unless the context dictates the contrary, all ranges set forth in this application should be interpreted as being inclusive of their endpoints and open-ended ranges should be interpreted to include only commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary.
The inventive subject matter is directed to keyboard switches (also referred to as key switches) that are configured for use with a sheet of membrane switches disposed below them. Mechanical keyboards are desirable for a variety of reasons, including how the keys feel when they are pressed. This feel comes from the nature of those switches: key switches in traditional mechanical keyboards feature mechanical switches therein, and when a key switch is actuated (by, e.g., a key press), the switch is actuated and a key is registered by a computer as being pressed. Mechanical keyboards are often used by gamers, and small enthusiast communities have created the space for an entire market segment. But creating a keyboard using mechanical key switches results in an expensive keyboard. Key switches of the inventive subject matter forego the inclusion of an actual switch built into each key switch and is instead configured to actuate a membrane switch. This configuration results in a less expensive key switch that has the same feel as a mechanical key switch.
Also shown in
Rocker 120 additionally features an actuator 130, is coupled with a bottom portion of the rocker 120 and configured to protrude through a hole in the bottom of the lower casing 106. In
The mechanics behind movement of rocker 120 are best seen in
Movement of plunger 102 is resisted by spring 136, which exerts an upward reactive force against the plunger 102 when the it is depressed according to the down arrow shown in
Hollow protrusion 140 also cooperates with spring 136 as well as piston 116. Hollow protrusion 140 can be seen in
Put together, key switches of the inventive subject matter prevent pressure from a user's finger from directly translating to a membrane, thereby reducing membrane wear and tear and increasing keyboard longevity. Instead, force from spring 128 causes rocker 120 to rotate such that its actuator 130 presses into a switching portion of the membrane 110. The pressure applied to the membrane 110 will not be impacted by how hard a user presses a key, and key switch force response that a user experiences is controlled by spring 136. Because spring 128 creates the force that is transferred to membrane 110 switch upon depressing plunger 102, spring 128 can thus be configured (e.g., its wire diameter, length, material, etc. can be deliberately selected) so that it creates a desired force that the rocker applies to the membrane 110.
Put together, embodiments of the inventive subject matter produce a force response like that of a key switch from a mechanical keyboard while maintaining advantages conferred by membrane keyboards.
Thus, specific systems and devices relating to key switches have been disclosed. It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts in this application. The inventive subject matter, therefore, is not to be restricted except in the spirit of the disclosure. Moreover, in interpreting the disclosure all terms should be interpreted in the broadest possible manner consistent with the context. In particular the terms “comprises” and “comprising” should be interpreted as referring to the elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps can be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.