GB2212317A

GB2212317A - Display devices

Info

Publication number: GB2212317A
Application number: GB8826238A
Authority: GB
Inventors: George Michael Waddington
Original assignee: AMS Ind PLC
Current assignee: AMS Ind PLC
Priority date: 1987-11-11
Filing date: 1988-11-09
Publication date: 1989-07-19
Anticipated expiration: 2008-11-09
Also published as: GB2212317B; GB8726365D0; GB8826238D0

Abstract

In a rotary control arrangement suitable for use in music mixing desks, a body e.g. a knob is formed at 2 to receive a centrally located spindle and information relating to a parameter controlled by the knob is displayed by an arrangement 6 e.g. optic fibres, formed within the knob. The rotary position of the knob as detected by a sensor (not shown) may correspond to a variety of operative conditions e.g. volume of sound source, stereo gain, and appropriate ones of LED or LCD elements 11 are controlled so that a desired pattern representative of the parameter being controlled is displayed at the top end of optic fibre elements 6 accommodated within closed or open channels in the knob. The display may be formed as a matrix of LED or LCD elements set into the top of the knob and controlled by a rotational position sensor ala a microprocessor and a display controller. <IMAGE>

Description

A ROTARY CONTROL r The present invention relates to a rotary control.

The control is particularly, but not exclusively intended for music mixing desks where in excess of a thousand rotary controls may be accommodated in a relatively small area. In a known desk, bar graphs, either horizontally or vertically arranged, are associated with rotary controls to display information in dependence upon the position of the controls. These bar graphs display the information quite satisfactorily but their horizontal or vertical extent imposes limitations on the density of controls which may be incorporated in the desk and therefore, for a given capacity increases the size of the desk. As these desks are usually controlled by a single person this is an important consideration.

According to the present invention there is provided a rotary control comprising a body formed to receive a substantially centrally located spindle, and means formed within the body for displaying information relating to a parameter controlled by the knob.

In a preferred embodiment of the invention, the rotary control comprises a substantially cylindrical body of synthetic plastics material through which a plurality of axially extending holes have been formed close to the periphery of the body. Each of these holes accommodates an optic fibre for the transmission of light. The body also defines a central axially extending bore to accommodate a spindle. At the lower end of each fibre, a light emitting element such as a light emitting diode or a liquid crystal display is disposed. The signals from these light emitting elements are transmitted by the optic fibres. By arranging the signals appropriately a variety of operative conditions can be represented.

In order that the invention may be more clearly understood, embodiments thereof will now be described by way of example with reference to the accompanying drawing, in which: Figure 1 is a plan view of one form of rotary control according to the invention, Figure 2 is a side elevation in section of the control of Figure 1, Figure 3 is a plan view of an alternative to the control of figures 1 and 2, Figure 4 is a plan view of another alternative to the control of Figures 1 and 2.

Figure5 is a perspective view of another alternative rotary control to that of Figure 1 and Figure 2, Figure 6 is an enlarged view of a part of the control of Figure 5.

Figure 7 is a modified rotary control similar to that of Figure 5, Figure 8 is a perspective view from the underside of a modification of the embodiment of Figure 5, Figure 9 is a perspective view from the underside of another modification of the embodiment of Figure 5, and Figure 10 is a block diagram showing the operational functions of the rotary control.

Referring to figures 1 and 2, the rotary control comprises a cylinder 1 of rigid synthetic plastics material such as acrylic. This cylinder is formed, for example by drilling or casting, with a blind recess 2 extending axially from its underside and into which a brass collet 3 is inserted. In use, the collet is mounted with a press fit on a spindle to mount the control. The knob may be mounted in a variety of other ways. For example, by splines, a D shaped shaft or screw. In the case of a screw the knob has a plane bore and the screw extends down the centre of the encoder shaft.

The cylinder 1 is also formed again, for example, by drilling or casting, with a plurality of channels 4. These channels are coaxial with the central axis 5 of the control and are disposed close to the periphery of the control in a ring around this central axis. They extend from the underside to the top surface of the control and each accommodates a fibre optic 6. The channels may be of closed cross section, as shown in figures 1 and 2, or may be of open cross-section in which case they may be formed by segments 10 cut fromthe cylindrical surface of the cylinder 1. Such an arrangement is shown in Figure 3.

The number of channels or segments incorporated will be governed by the diameter of the rotary control and the size of the fibre optics. In one example, however, the control has a diameter of 15mm and houses fibre optics each 2mm in diameter.

In use a light emitting element 11 is disposed on the underside of each fibre optic 6. The element may be a light emitting diode or a back lit liquid crystal display. Each fibre optic carries the light from its respective light emitting element 11 from the underside of the control to its upper surface to display the light at that surface.

Electronic circuitry is disposed between the spindle and the light emitting element so that a variety of operative states can be displayed by the fibre optics. For example, where the control position simply represents the volume of a particular sound source, that volume can be represented by the progressive illumination of diodes from a zero reference point so that a curved illuminated line of increasing or decreasing length is produced as the control is turned to increase or decrease the volume.

Alternatively, the volume may simply be indicated by the illumination of a single appropriately positioned diode, this diode changing as the volume is increased or decreased. Specific permutations of illuminated diodes may be selected to represent specific operational conditions.

For example, a castellated display, where every other diode is illuminated progressively can be used to indicate stereo gain for example.

Figure 5 shows a further embodiment of the invention.

In this arrangement the rotary control has a matrix 20 set into the top of the control. This may be square or circular tailored to the shape of the knob. A display controller is associated with the display. The matrix may comprise a plurality of light emitting diodes or liquid crystal display elements or pixels. These elements/pixels may be polygonal, for example, hexagonal, as the image/knob may stop in any position. In one form the diodes or elements have an area of 0.3 mm2 and are spaced about 0.05 mm apart. An arrangement having sixteen such diodes or elements 25 arranged in a four square display is shown in Figure 6. The knob itself has concentrically arranged inner and outer parts 21 and 22. The inner part. is static and supports the matrix and the outer part is mounted for relative rotational movement about the inner part.The outer part supports a circumferential graticule 23 at its base. A sensor reader 24 is disposed adjacent the graticule. These two parts comprise a rotary shaft encoder. Information relating to the parameter being controlled is transferred via this contractless sensor graticule arrangement and is displayed by the elements of the matrix 20.

Figure 7 shows an alternative embodiment to the embodiment of Figure 5. The control of this figure also has inner and outer relatively rotational parts 30 and 31.

The inner part is static and supports a matrix 32 as in the Figure 5 embodiment. The outer part rotates around the inner part and has a downwardly dependent extension 35. This extension 35 supports a plurality of horizontally disposed parallel arranged slip rings of conductive material. The graticule and reader (referenced 33) and the electronics for controlling the display, which may, for example, be in the form of a dot matrix or ring is incorporated in the knob. The whole assembly, including the display, rotates.

To maintain a static image, data is fed to the display controller to rotate the image in the opposite direction to but at the same rate as that of the knob being adjusted.

The slip rings supply the power and data connections for the controller. The pixels of the display can be polygonal, for example, hexagonal in order to improve resolution as the image or knob may stop in any position.

As with the embodiment of Figure 5 a rotary shaft encoder comprising a graticule 33 and reader 34 is provided. In both embodiments, the positional data of the encoder is read by a microprocessor which then transmits instruction to the display controller as appropriate.

Figures 8 and 9 respectively show alternative information transfer arrangements to the graticule and slip rings of the embodiments of Figures 5 and 7. In the arrangement of Figure 8, an electrically conductive contact 40 cooperates with spaced carbon segments 41 disposed around the underside of the outer rotational part of the two part control. In the arrangement of Figure 9, the carbon segments are effectively replaced by either spaced non-reflective or spaced reflective areas 50. A sensor 51 cooperates with the areas 50 to provide a contactless information transmission arrangement.

Figure 10 is a block diagram showing the operational functions of the rotary control just described. Rotating the control correspondingly alters the position of the rotary encoder 90. This movement is fed to control gearing 91 which may convert it into a larger or smaller change in process level to give single or multi-turn control. The resultant change in value is applied to the selected parameters of the process under control 92. In an audio process these may be volume level filter frequency, filter cut or boost. The continuation variation of these process parameters may be stored at 93 and this stored information used subsequently for automatic process control.

The process control electronics 92 produce a value to be displayed relating to the selected process parameters.

This is fed to the display controller 94 which converts the control value into the required display format with correct orientation. This may for example be a single dot, solid bar or numeric value. The controller 94 outputs a signal representing the required display to the display 95 which may comprise a ring of LED's a custom made LCD or a dot matrix.

It will be appreciated that the above embodiments have been described by way of example only and that many variations are possible without departing from the invention. For example, referring to Figure 4, the fibre optics may be replaced by a light guide in which each channel may be replaced by a bundle of fibre optics forming a ring 1 in which alpha-numeric characters can be transmitted thus greatly increasing the versatility of the control for transmitting operational information.

Different colours may also be used to indicate different information.

Claims

1. A rotary control comprising a body formed to receive a substantially centrally located spindle, and means formed within the body for displaying information relating to a parameter controlled by the knob.

2. A rotary control as claimed in claim 1 in which the means formed within the body for displaying information comprise a plurality of individual channels for the transmission of light signals disposed around the axis of rotation of the control.

3. A rotary control as claimed in claim 2, in which the plurality of individual channels are formed by respective optic fibres.

4. A rotary control as claimed in claim 2, in which the plurality of individual channels are formed by respective wave guides each of which comprises a bundle of optic fibres.

5. A rotary control as claimed in claim 2, comprising a plurality of passages extending axially through the body in which the individual channels are respectively disposed.

6. A rotary control as claimed in claim 5, in which the passages are formed by bores of closed cross section.

7. A rotary control as claimed in claim 5, in which the passages are formed by slots in the surface of the body.

8. A rotary control as claimed in claim 7, in which the body is generally cylindrical and the slots comprise segments of the cylinder.

9. A rotary control as claimed in any of claims 2 to 8, in which a light transmitting element is disposed at one end of each individual channel.

10. A rotary control as claimed in claim 9, in which each light transmitting element is a light emitting diode.

11. A rotary control as claimed in claim 9, in which each light transmitting element is a liquid crystal display.

12. A rotary control as claimed in claim 9, 10 or 11 in which circuitry is connected to the light transmitting elements enabling certain selected ones of those elements to be activated to respresent certain selected conditions.

13. A rotary control as claimed in claim 1, in which the means formed within the body comprises a matrix of information display elements to which the information to be displayed is fed electrically.

14. A rotary control as claimed in claim 13, in which the information display elements comprise a plurality of light emitting diodes.

15. A rotary control as claimed in claim 13, in which the information display elements comprises a plurality of liquid crystal displays.

16. A rotary control as claimed in claim 13, in which the body comprises two relatively movable parts one of which is normally static and includes the matrix and the other of which receives information electrically for display by the matrix.

17. A rotary control as claimed in claim 13, in which the matrix rotates and the information display is kept static by feeding data to rotate the display at the same rate as but in the opposite direction to the matrix itself.

18. A rotary control as claimed in claim 17, in which a display controller is provided for controlling the information display and slip rings are provided for feeding power and data to the controller.

19. A rotary control as claimed in claim 18, in which a shaft encoder is provided to indicate the rotational position of the control and a microprocessor is associated with the encoder operated to receive positional data from the encoder and transmit appropriate signals to the display controller.

20. A rotary control substantially as hereinbefore described with reference to Figures 1 and 2, or 3, or 4, or 5 and 6, or 7, or 8, or 9, or 10 of the accompanying drawings.