Cooking appliance controls

#The present invention relates to cooking apparatus, in particular to controls thereof. Of recent years there have been various developments moving away from conventional knob or tap type controls for hobs, ovens, and other cooking appliances, varying degrees of automation being introduced. In particular, it is known to provide an array of keys which select particular facilities on the appliance e.g. FRONT LEFT RING or MAIN OVEN and so on, and which allow the cooking temperature of the selected facility to be preset, either as an actual temperature in the case of, say, an oven or as a scale value, e.g. a number from 1 to 9, in the case of say, a hob ring. An actual temperature setting causes the power input to the selected facility to be controlled by feedback from a temperature sensor. A scale value setting directly determines the mean power input to the selected facility.

#In order to simplify the control keys it is known to utilize an UP and a DOWN key in conjunction with a display which shows the preset temperature value for the selected facility. The UP key causes the present value to step upwardly, e.g. by ten degree increments of unity or fractional increments in the case of a scale number. The user presses this key until the displayed value reaches the desired value and then removes his or her finger. The DOWN key operates in the converse manner.

#It is possible to provide separate UP and DOWN keys and also an OFF key for each facility, whereby use of these keys also effects selection of the facility. The DOWN key can be omitted if the user is required to reduce the temperature by use of the OFF key and then the UP key. It is also possible to use UP, DOWN and OFF keys shared between separate facilities by use of multiplexing techniques, additional keys then being required for selection of the facilities.

#The invention will be described in more detail, by way of example, with reference to the accompanying drawings, in which:

#FIG. 1 is a block diagram of hardware embodiment of the invention.

#FIG. 2 is a flow diagram of a software embodiment of the invention.

#There will first of all be described a hardware embodiment of the invention illustrating clearly the principles of the control means. It will be understood that the functions of the various blocks can readily be performed by corresponding microprocessor programs, one suitable microprocessor being Texas Instruments TMS 1000.

#The embodiment illustrated in FIG. 1 relates to one ring of a hob, the illustrated circuitry and touch pads being repeated for the other rings. A control panel on the hob comprises in respect of each ring an UP pad 11, a down pad 12, an OFF pad 13 and a digital display device 14.

#The touch pads control the application of signals described below to an up/down counter 18, which stores values from 0 to 9 and which may be a single decade BCD counter. The bit-parallel outputs from the counter on lines 19 are applied to a conventional controller (not shown) such as a thyristor controller which controls the supply of power to the ring, from power off when a counter stores 0 up to full power when the counter stores 9. The lines 19 are also connected to the display device 14 and to a decoder 20 whose function is described below.