FI118978B - Testing apparatus for a keyboard - Google Patents

Description

118978 Keyboard tester - Testningsapparat för en tastatur

The invention relates generally to testing the operation of keyboards and other electromechanical devices comprising a matrix of push switches. In particular, the invention relates to optimizing the design of a device suitable for such testing.

The keyboard or keypad comprises a matrix of pressed keys. The difference between a keyboard and a keyboard is not entirely clear and is not relevant to the present invention. For simplicity, the term "keyboard" 10 is used to refer to any type of electromechanical device that includes a set of mechanically movable keys that need to be tested, for example, as part of a manufacturing line, to ensure their correct operation before being sent to a customer.

It is common to use a tester with a plurality of pneumatic pistons repeatedly pressing the keys of the keyboard being tested. The operation of the pneumatic pistons is controlled by a computer, which also receives electrical inputs generated by the keyboard in response to the presses. The tester monitors the received electrical inputs to ensure that each keystroke triggers an appropriate response on the keyboard.

Fig. 1 schematically shows a prior art test apparatus. The testing computer 101 controls the valves of the valve assembly 102. A separate pressure hose extends from the electrically controlled valve 102 to the corresponding piston 103 of the jacket. The keypad 104 to be tested is placed in a test adapter 105 from which i ...: the cable passes to the test computer 101. The device 104 shown in FIG. 1 may also: # be a complete electronic device such as a computer, mobile, or the like. keyboard as part of the device. The disadvantage of this prior art arrangement is that a large number of pressure hoses are required between the valve assembly 102 and the piston assembly 103, which makes the device as a whole relatively clumsy and also * ··· increases the manufacturing cost. In addition, this solution requires the same number of electric • · **. * 30 pressure controlled valves as the keypad under test has.

. ···. Typically, it is not possible to completely avoid the use of pressure hoses by connecting the valve assembly 102 to the piston assembly 103, as this would increase the spacing of the test adapter 105! * the complexity of the equipment in the immediate vicinity and would require the pneumatic tube 106 to be led all the way to the test bench.

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In many cases, the testing procedure and keypad structure allow two or more keys to be tested simultaneously, i. pressing multiple keys simultaneously and monitoring each generated response separately. However, the electrical principle of the keyboard usually requires that the keys being pressed simultaneously are not adjacent, but spaced sufficiently apart on the keyboard, and in different horizontal or vertical rows, or the like. This results in the prior art solution of Figure 2. Each valve of the valve assembly 202 exits a pressure hose to a branch block, exemplified by a branch block 203. The branch block has one input for receiving a pressure hose from valve 10 and a plurality of outputs. Each outlet has a pressure hose for piston 103 piston.

This solution helps to reduce the number of electrically controlled valves required and also to some extent reduce the total length of piping required, but does not simplify the appearance of the test bench. In addition, it increases the possibility of errors in assembly of the test apparatus, since the pressure hoses 15 from the branch blocks must go to seemingly arbitrary locations in the piston, with a high risk of confusion.

It is an object of the present invention to provide a keyboard tester which is inexpensive to manufacture, easy and quick to assemble and requires only a small number of components. It is also an object of the present invention to provide a testing device that is easily and quickly convertible to different types of keystrokes: ···;

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The objects of the invention are achieved by a plunger having internal branching channels

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. . ·. the base body.

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The testing apparatus according to the invention includes a body having inputs, outputs 25 and channels between inputs and outputs, and a plurality of piston pistons connected to the body inputs, which are arranged for use by a hate medium directed to the inputs of the body. The test apparatus is characterized in that the number of frame inputs .Λ, is smaller than the number of frame outputs, and at least one of said channels is a branching channel which leads to at least two non-take-offs from one input to **; · 30.

···, Keys that are pressed simultaneously are groups of non-adjacent keys.

• · "* These groups overlap with each other, which means that if compressed air is to be supplied to the corresponding piston groups in the piston, the channels overlap with each other in a fairly complex manner. Traditional manufacturing methods such as po 118978 3 and milling do not assembling a section through which the channels pass through a plurality of separately machined subcomponents.

However, according to the invention, it is possible to produce in a practical and economical manner an integral body comprising a complex structure of overlapping channels. Most preferably, this is done using a method known as "rapid prototyping". The piece to be manufactured acts as a piston body so that the pneumatic pistons are attached directly to the outlet end of each channel. The other side (s) of the body member have a plurality of inlets, clearly less than the number of pistons. Electronically controlled valves can be connected to said inputs either directly or via pressure hoses.

Selective laser sintering (SLS) is considered to be the most promising method of rapid prototyping for the manufacture of a body. In the SLS process, the raw material is in powder form in a container. A properly aligned laser beam heats the powder of the thin layer 15 at selected locations so that it sintered on the previous layer. The finished part of the workpiece moves stepwise away from the laser focal plane, whereby the workpiece is shaped layer by layer until it has reached its final shape.

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Several materials can be used in the manufacture of the body based on selective laser sintering. Polyamide, with or without reinforced glass powder, with an average particle size of about 60 micrometers or less, has been considered the most preferred choice.

The examples exemplified in this patent application are not to be construed as limiting the applicability of the appended claims. The verb "comprising" is used in this patent application as an open limitation which does not exclude features other than those mentioned herein. The features mentioned in the dependent claims ·] [[:] may be freely combined, unless otherwise stated in the name ·! ·.

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The novel features considered to be characteristic of the invention are set forth in detail in the appended claims. The invention itself, its structure and function ···. however, the principle of tapering, and its additional objects and advantages, will be described below with reference to some embodiments and with reference to the accompanying drawings.

4, 118978

Figure 1 schematically illustrates one prior art test arrangement, Figure 2 schematically illustrates another prior art test arrangement, Figure 3 illustrates an example of a rapid prototyping device, Figure 4 illustrates an example channel arrangement, Figures 5a-5e illustrate the channel arrangement of Figure 4. 5 branch channels, Figs. 6a-6e show layers in a body part comprising a channel arrangement of Fig. 4, Fig. 7 illustrates a testing device according to an embodiment of the invention, and Fig. 8 shows a body part of the testing device of Fig. 7.

The generic term "rapid prototyping", or its abbreviation RP, has been used for methods developed to rapidly provide a three-dimensional visual representation of 15 digitally designed bodies of closed volume. Rapid prototyping methods typically require input data from a three-dimensional design software in one of several possible standard formats, such as IGES (Initial Graphics Exchange Specification), VDAFS (Verband der Automobil-Hersteller Flächenschnittstelle) or STEP (Standard Model of the Exchange of Product) ** data). One method step, which is the de facto standard, is to enter such a feed. ···. conversion of working data into a so-called STL (Stereolitography Language), in which the continuous surface is replaced by a triangular oriented element.

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Further processing of data in STL format depends on the rapid prototyping '* "* method involved, but since substantially all known RP methods produce • · · 25 final objects by building two-dimensional layers on top of each other, such' ··· 'further processing typically includes such deriving two-dimensional layer descriptions from a STL presentation.

• · • · • · ·. ···. One group of RP methods is commonly known as three-dimensional printing, which • · T * basically means injecting liquid or viscous waxy material into two-dimensional patterns of finite thickness. Each layer solidifies ·· · on the previous one so that the final shape of the desired piece is actually a stack of solid wax layers on top of each other. Used for 3D printing. ···. The trade names of these systems include: JP-System 5 (Scroff Development Inc.), • ·

Ballistic Particle Manufacturing (BPM Technology Inc.), Model Maker (Solidscape 35 Inc.), Multi Jet Modeling (3D Systems Inc.), and Z402 System (Z Corporation). Pieces made with three-dimensional printing are rarely suitable for anything other than single use molds for viewing or use, as their mechanical strength is at best modest.

In contrast to three-dimensional printing, there is a group of RP methods, loosely defined as "technical prototyping", which use raw materials which are cured in a chemical reaction as part of the process or immediately thereafter. The technical prototyping methods known at the time of writing this specification are as follows:

Stereolithography: a liquid photosensitive epoxy resin in a vessel, solidified layer by layer with the aid of a focused laser beam.

Selective laser sintering: Raw material in powder form, sintered layer by layer by heating with a focused laser beam that draws a two-dimensional shape of the layer.

Laminated part modeling: thin sheets of plastic or paper are glued together and the outline of each new layer is laser cut before the new layer is made.

Fused Deposit Modeling: resembles three-dimensional printing, but using a thermoplastic "ink" containing acrylic-nitrile-butadiene-styrene, polycarbonate, polyphenolsulfone, or polyester.

20 - 3D Plotting: The base and support / curing agent are sprayed separately. · * *. for rapid curing.

..II: - Solid Ground Curing: a whole layer of the pattern is cured at once • ..... using ultraviolet light through the pattern mask.

• · • · ·:: V Traditionally, RP methods have not been considered suitable for industrial purposes for various reasons. The precision of the RP methods was not considered sufficient; for many industrial applications the accuracy should be better than ± 0.1 milli -; * ... meters. For RP products made in two-dimensional overlapping layers. ···. na, it is characteristic that the edges of the layers remain visible in the finished product so that its surfaces have a "stepped" appearance, which is considered non-flammable in final products for industrial use. RP-methods

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at least the mechanical durability of the models made has been called into question.

I. / Contrary to the foregoing doubts, selective laser sintering (SLS) was found to provide a useful basis for a method for producing body parts for fully functional use. The SLS device shown in Fig. 3 includes a manufacturing chamber 35 301 having a relatively high internal temperature and preferably an inert atmosphere. The infrared heater 302 keeps the powdery raw material close to its melting or softening point, thereby reducing the need for heating energy required by the laser beam, and further reducing temperature differences and resulting stresses in the partially manufactured product. Roll 303 applies a uniform layer of raw material to the working area located in the tank 304. The piston 305 5 on the bottom of the tank 304 moves vertically. After the layer of raw material is applied, the laser beam from the laser source 306 scans through a two-dimensional mold that defines the shape of the product to be manufactured in the alternating layer. Typically, the outline of a layer is first drawn, and the volume remaining within the outline is then systematically scanned. Electronically controlled collimation and focusing means 307 10 provides proper guidance and alignment of the laser beam. The heating effect of the laser beam in the fresh layer of raw material causes a sintering reaction which binds the particles of the new layer to the previous layers.

After laser scanning, the piston 305 moves downwardly in accordance with the layer thickness, and the described process begins again from the beginning. After all layers have been sintered, the process is completed by cooling the finished workpieces and removing the non-sintered raw material using, for example, a compressed air jet or a soft brush. Unused raw material can be returned to the process for use in the next manufacturing cycle. Cooling should be done slowly to prevent internal tensions.

··· * · * ;;; * The advantage of SLS as a manufacturing method is that the non-sintered raw material serves as a support for workpieces. No additional support is required even if several separate pieces are prepared at the same time.

· «· • ·. One exemplary arrangement that may be used to fabricate the body comprises: ·· *. SLS type EOSINT P 380 manufactured by Electro Optical Systems • · 25 GmbH. The default thickness of the layer with said device is 0.15 mm and the yield in the vertical direction is 10-25 millimeters per hour. For the above example arrangement • ·: 4> [* conversion of CAD image data to STL format was done with Magics RP computer program: ···: which is also arranged to optimally position the pieces to be manufactured so that they are not less than 6 mm vertically . Slice- • •. ···. The control of 30 control commands was performed using EOS-RP-Tools computer software. The EOSINT P 380 incorporates a 50-watt carbon dioxide laser that moves at a speed of 5 meters per second. The maximum dimensions of the piece produced in said device are 340 (width) x 340 (length) x 620 (height) millimeters.

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Examples of materials suitable for the manufacture of the body include, but are not limited to, polyamide-based materials such as Stability Enhanced Basic Polyamide-12 (Polylaurine Lactam), known as PA 2200, Glass Reinforced Polyamide, PA 3200 GF, and Aluminum Enamel, is a registered trademark of Electro Optical Systems GmbH. The average particle size of PA 2200 and PA 3200 GF, which gave satisfactory results, was 60 micrometers. Even smaller particle sizes are likely to produce even better results with smoother surfaces and a smoother appearance. Hard reinforcement materials such as PA 10 3200 GF glass reinforcement may increase the risk of visible scratching of the device under test if it accidentally touches the body. Better conductivity of aluminum-reinforced plastics over conventional dielectric polymers may be advantageous in solutions requiring good protection against electrostatic discharge. Another suitable material is po-15 lystyrene available under the trade name PS 2500.

Due to shrinkage during the cooling phase, the finished product has slightly smaller dimensions than those used in manufacture. The exact amount of shrinkage depends on parameters such as preheating temperature, laser power, laser speed of movement, and cooling time, but also on the amount of kappa manufactured; ** ·. 20 lath geometry, thickness and manufacturing orientation, as well as selected raw material. * ··. For example, if the raw material is Alumide®, the shrinkage in the x and y directions is 2.2-2.3% and in the z direction 1.5-1.6% for large pieces and 0.4-0.7% small. The Z direction is the thickness direction of the two-dimensional layers, i.e. a direction parallel to one-*** f of the movement of the piston 105 shown in the diagram of Figure 1. X- and Y-axis

• * I

The natures are arbitrary directions perpendicular to said z-directions and to each other. The adaptation of the CAD-based data to take into account the shrinkage is most advantageously done in the orientation Goka, as mentioned above, made by j ** ·. using a Magics RP computer program) but before executing a slit control command (using the EOS-RP-Tools computer program). It is not advisable to make changes to the drawings of the part after the shrinkage compensation has been performed.

• · • · • a ·

Fig. 4 is an isometric projection of an exemplary channel arrangement that should be present in a body part according to an embodiment of the invention. The plane 401 corresponds to the underside of the body, and the ellipses 35 in the plane 401 illustrate the holes to which the pneumatic pistons should be attached. The upward-facing line ends 402, 403, 404, 405 and 406 represent the feed holes into which the pressure hoses should come from electrically controlled valves. From each feed hole, the branch passage leads to a plurality of holes corresponding to keys which can be simultaneously pressed according to the test procedure and keyboard structure. As shown in Figure 4, the five branching channels together form a relatively complex structure. Each of the channels is shown separately in Figures 5a-5e.

Figures 6a-6e show the same channel arrangement example. Each of these figures is a horizontal plan view through the exemplary body portion. The oblique lines in Fig. 6a show which holes in the bottom (piston) plane belong to the same group: for example, the holes in A1, B3, C2, D4 and E3 all correspond to the keys of the 10 keyboards to be tested which can be pressed simultaneously. In Figs. 6b and 6e, the same types of lines illustrate the horizontal portions of the different branching channels. The holes are shown as circles in Figures 6a-6e. The "o" in the circle indicates that the hole extends upward from that plane in the body (i.e., out of the paper plane in Figures 6a-6e), "x" indicates that the hole extends downward from that plane in the body (i.e., the paper in Figures 6a-6e) ), and both "o" and "x" in a circle indicate that the hole passes through that plane, i.e., extends from that plane both up and down in the body portion. The lines that divide each plane view into a 6x4 box in Figures 6a-6e are fictional: they merely make it easier to understand how the elements described are relative to one another.

• M • · 20 The layouts in Figures 6a-6e show a kind of rough pattern or intermediate steps of how the layered operating instructions for an RP device look. If we consider *: **; SLS, the first layer to be sintered is shown in Figure 6a. The following layers have only the same vertical holes through them until a layer: t: [: one-half the width of the channel lower than the layer of Figure 6b (assuming the layers · ** '· 25 are as high as the width) bases for horizontal ** · channel sections. Horizontal channel sections are gradually widening:. 6b in the following layers, until the exact layer of Fig. 6b appears, after which the · · · lateral portions of the duct taper again *: ** and finally disappear as the mid-layer of the layers in Figs. 6b and 6c approaches. Continuing • · v: 30 in the same way and sintering the body portion one layer at a time results in the desired shape through which the branching channels criss-cross each other in a way that would be difficult or impossible to accomplish, e.g. milling the palette.

• # ·· «

The precise grouping of the piston holes and the precise channel shapes in Figures 4-6e are, of course, only examples. An arbitrary keypad generally has a different number of keys and, in a different geometry than the 6x4, the number and position of the simultaneously pressed keys allowed by the test procedure and the keyboard structure may vary from one type of keypad to a plurality of piston hole sets. etc. However, once the skilled artisan has the technical knowledge of the keyboard to be tested, it is relatively easy to design the correct structure of the branching passages through the body portion with as few feed holes as possible, leading each branch to a piston hole corresponding only to keys that can be pressed simultaneously during testing.

Figure 7 schematically shows a testing apparatus 10 according to an embodiment of the invention. Test computer 101 may be similar to those used in the prior art devices of Figures 1 and 2, provided that the computer is programmed to execute a test program that depresses certain key groups of the keyboard 104 being tested. Also, the test adapter 105 may be similar to that used in prior art devices, and the device designated 104 may be a complete electronic device, such as a computer, mobile station or the like, which includes a keyboard as part of the device. The valve assembly 202 need only contain as many electrically controlled valves as there are pressable key groups for testing, thus resembling that used in the prior art device of FIG. Of course, the invention does not exclude that the valve assembly includes more than one valve. Keyboard, ···. The multipurpose testing department of 20 production plants may include fixed installations with: · ***. The valves include numerous electrically controlled valves. When testing a particular «« type of keyboard, only the required number of valves is introduced. The present invention .. * is very advantageous in such cases, because the use of SLS or other • · * ··; * RP methods enables the rapid manufacture of the required body parts * .i.! 25 for any particular test application.

··· * · • «···

The obvious difference with prior art devices is that the pressure hoses: ·. from 202 to body 703 there are only as many key groups as there are. Fig. 8 I ··. Shows how the body portion 703 includes a plurality of inlet connectors 801, each of which includes a pressure hose 802. On the opposite side of the body portion 703 are pistons • · \ v 30 803. Each inlet connector and each piston is typically a discrete piece imprinted or punched in a hole in the body. If the material strength obtained by making the body part 703 by SLS or other suitable RP method is ·, it is even possible to make at least the inlet connectors ***** 801 and possibly also the piston mechanisms for the body part 703 as integrated parts.

The above exemplary embodiments of the invention are not to be construed as limiting. As a natural example, the number of inputs and outputs of the body is not limited to the above; the number of inputs and outputs can be anything up to a certain maximum, depending on the size limits of the manufacturing process. Another example is the use of the word "pneumatic"; Although compressed air is the most readily available fluid to be passed through the body passages to drive the pistons, the invention does not exclude the use of other fluid media, such as gases or even liquids such as water or hydraulic oil. Instead of the valves being in a separate valve assembly, they can be mounted directly on the inlet of the body; however, this requires bringing the pneumatic tube to which the valves are connected up to the test bench. Another noteworthy fact is that the invention does not require all inputs to be on one side of the body. The inputs can very well be split into two, three, etc. sides of the frame, or even all sides of it. The ducts do not need to have horizontal sections or even any straight sections except those where the pistons and any inlet plugs enter.

A more far-reaching change in the configuration, however still within the scope of the present invention, would include programming the keyboard (or device of which the keyboard is a part) to include a testing routine that checks for responses to predetermined sets of keystrokes. feed back from the keyboard or device being tested to the valve control device.

··· 20 It should be noted that although RP in general and SLS in particular are considered by far the · · · most advantageous ways to fabricate a body with overlapping channels, they are not the only option. Referring to Figures 6a-6e, it would be possible, for example, to construct the same frame member of four horizontal tiles with ··· such that the bottom surface of the lower tile has the shape and the same as in Fig. 6a. The top surface of the 25 man tile would have the shape shown in Figure 6b: the horizontal duct portions would be grooves on the top surface of the tile. The second plate would have the bottom side surface of Figure 6b and the top side surface of Figure 6c, and so on. The tiles could be made, for example, of aluminum or some suitable easy-to-use plastic such as polyester, polyvinyl chloride or polytetrafluoride.

: A: 30 The problem with such a method would be to get even portions of the tile surface smooth enough so that the seams between the tiles become sufficiently airtight. in the final configuration. Of course, it would be possible to use some kind of glue, ["* rubber gasket or other gasket material between the tiles, but this would add to the complexity of the manufacturing process and thus the cost.

Claims (9)

A test device for testing a keyboard or electronic device with a keyboard, the test device comprising: - a body part (703) with inputs, outputs and channels between the inputs and the outputs, - a plurality of pistons (803) coupled to the outlets (703) of the body part and which are arranged to be driven by a flowing medium which is led to the inputs of the body part (703); characterized in that: 20. the number of inputs in the body part (703) is smaller than the number of outputs in the body part (703), and - at least one of said channels is a branch channel leading from an input to at least two non-adjacent outputs. *** • · • · • · ·. ···. 25 Testing device according to claim 1, characterized in that the body part (703) comprises several branching channels, each of which leads from an entrance to the at least two non-adjacent outputs, so that the branching channels of the said branch "**" It runs intertwined within the body portion (703). * ··· * 30 Test device according to claim 1, characterized in that the body part (703) is a unitary piece manufactured by a rapid prototyping method. • · • · * · » Test device according to claim 3, characterized in that the body part (703) is: a unitary piece made using selective laser sintering. • · · 35 Test device according to claim 1, characterized in that it comprises a *: **: a plurality of electrically controllable valves, by means of which said flowing medium ·: ··: is selectively guided to the inputs of the body part (703). 13 118978 Test device according to claim 5, characterized in that: - the electrically controlled valves are located in a valve compartment (202), separate from the body part (703), 5. the entrance of each body part (703) comprises an input connection (801), and - from each of said valves, a pressure hose (802) leads to one of said input connections (801). Test device according to claim 5, characterized in that the electrically controllable valves are located in the inputs of the body part (703). Testing device according to claim 1, characterized in that: - the test device comprises a test adapter (105) adjacent to the body part (703) for receiving the keyboard (104) to be tested, the test device comprises a testing computer (101), and (101) is arranged to control the input of the flowing medium to the inputs of the body part (703) and to receive responses from the keyboard (104) to be tested via said test adapter (105). · · • ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ·· ft ft ft ft ft • · ft · ft ft • • • · · ft ft · ft ft • • · ft ft · • ft ft