GB2145258A - A display repeater - Google Patents

Abstract

The repeater comprises an array of light sensors 21 and may overlie a light-emitting display 20 so that each element of the display is read by a respective sensor. A processor 22 encodes the sensor outputs and supplies signals to a local and a remote repeater display 23, 24. The repeater displays display the information read from the display 20 which is obscured by the sensing means 21. The output of the processor may also be supplied to apparatus 25 such as a computer or recording apparatus. The repeater allows data displayed on the display 20, for instance the display of a cash register, to be displayed remotely and to be stored without an electrical connection to the display 20 being necessary and without the cash register operator losing sight of the information being displayed. <IMAGE>

Description

SPECIFICATION A display repeater This invention relates to an electronic system for repeating on another display the information appearing on the observed one.

Many pieces of electronic equipment now contain electro-optical displays to indicate the result of calculations ortests performed by the internal circuitry. For instance, the electronic cash register, the petrol pump, a score-board, the calculator and measuring equipment are all examples. During normal use and during the testing of these types of equipment, it is useful for the information displayed to be relayed elsewhere and recorded. This is often done by sending electrical signals through a cable to a remote display. However, this method requires extra circuitry within the equipment and an electrical connection between the equipment and the remote display, printer or recorder. Such a method does not check the actual display but only the signals driving it.

An alternative approach avoiding electrical connection may be to scan the display with a closed circuit television camera and therefore provide a remote picture. However, this has the disadvantage of either obscuring the display from the operator or allowing the operator to obscure the display from the camera either intentionally or unintentionally.

Also, it is not straight4orward to convert the resulting signals into a recordable form for interpretation by computer or other electrical system.

The present invention relates to electronic equipment for observing an electro-optical display (which typically could display alphanumeric characters but might indicate other symbols depending on the nature of the information to be displayed) and reproducing identical information both on a local display and on a remote display. The equipment comprises a sensing means containing a plurality of electromagnetic radiation sensors mounted over, in front of, or adjacent to the elements of an electrooptical display to be observed, a processing means for converting the signals emanating from the sensors into electrically coded information, a local display means for repeating the observed display information and one or more remote display means for repeating the observed display information.

The sensing means may consist of a collimating or focussing arrangement for each sensor so that only one element of the electro-optical display may be observed by each electromagnetic radiation sensor.

But more than one sensor may be used per element.

The sensing means may be positioned so that it obscures the observed display in order that no radiation, other than that from the electro-optical elements of the display, can reach the sensors. The processing means comprises electronic circuitry to distinguish which sensors are being activated by radiation at any one time and to produce coded signals which can be interpreted by a remote computer, printer or recording means unambiguously. The processing means may cater for continuously energised display elements or those in which different elements are energised at different times (time-multiplexed displays).

A local display means reconverts the signals emanating from the processing means into a repe ated identical display which can be mounted above, in front of or adjacent to the equipment in case the original observed display is obscured by the sensing means.

The processing means may transmit signals describing the state of the display by electrical, electro magnetic, acoustic or other transmission means to a remote location where the remote display means may repeat the observed display in identical form or in a modified form (i.e. larger or smaller, a different colour or font or even a subset of the original information).

The remote display means may not necessarily need to be removed far from the observed display and may comprise electrical systems for interpreting the coded signals such as computers or recording devices.

The present invention enables the alphanumeric characters, or other symbols, on an electro-optical display to be monitored and converted into electrical signals without electrical contact between the display equipment and the sensing device. Because of the local repeater display the information is still provided for the operator and therefore any malfunction of the sensing device may be quickly detected.

Because of the close proximity of the observed display and sensors the observation cannot easily be obscured and the resulting signals can be readily accumulated or adapted for a variety of displays in a computer based system.

A particular embodiment of the invention is iliustrated in the accompanying figures.

Figure 1 a cross-sectional view of the equipment mounted on a cash register to observe the electrooptical display.

Figure 2 a schematic diagram of the system.

Figure 3 details of the sensor mounting block and interconnecting circuit board showing the relative positions of the sensors with respect to the display elements.

The particular embodiment of the invention shown in the drawing (Figure No. 1) is used to monitor the display in an electronic cash register.

The display may be any type of light emitting arrangement (e.g. I.e.d., gas discharge or electroluminescent). The display (10) mounted behind the window (11 ) within the cash register's casing (12) is observed by the sensors (13) mounted within a block (14) through which holes are drilled to collimate the light onto each sensor. The sensors are connected via a printed circuit board (15) to the processing circuitry (16) which in turn is connected to the local repeater display (17) which may be viewed by the operator. The transmission cable to a remote display and the power supply for the unit are not shown in this diagram to avoid confusion.

In the schematic diagram (Figure No. 2) the sensors (21), of which only three are shown to simplify the diagram, but there may be as many as there are display elements to be observed, each monitor one of the elements in the observed display (20). The processing circuitry is located within the block (22) and from this electrical connections link to a local repeater display (23), a remote repeater display (24) and also, if required a computer, recording equipment or other electrical systems (25).

Electrical power may be provided from a power supply unit (26) mounted nearby which may either use mains electricity or batteries.

The upper part of Figure No 3 shows a plan view of the block in which the sensors are mounted with the relative positions of the observed display elements shown with dotted lines. The lower part of the finger shows the printed circuit board used to connect the sensor phototransistors to the processing electronics. In order to cope with different display arrangements on a variety of equipment the physical dimensions of the two items shown in Figure No. 3 would be altered but none of the rest of the equipment should need to be changed, therefore minimising differences between various models.

Claims (8)

1. A display repeater comprising sensing means locatable to overlie the face of a light-emitting display to read the display, and first and second repeater displays located respectively local to and remote from the sensing means and responsive to the output of the sensing means to display information shown on the overlaid display.

2. A repeater according to claim 1, in which the sensing means comprises an array of sensors mounted on a supporting member in a predetermined pattern corresponding to the pattern of elements in a display to be read, so that, in use, each element of the display is read by a respective sensor or group of sensors.

3. A repeater according to claim 2, in which the sensing means further comprises an opaque member having passages or light-transmitting regions extending therethrough which collimate light entering the repeater from the display, before the light falls on the sensors.

4. A repeater according to claim 2 or 3, in which the sensing means comprises processing means which, in use, electrically encode the output of the sensors to form the sensing means output.

5. A repeater according to any preceding claim, further comprising data processing and/or recording equipment receiving the sensing means output.

6. A repeater according to claim 5, wherein the data processing and/or recording equipment is remote from the sensing means.

7. A display repeater according to any preceding claim, comprising a housing in which the sensing means and the local repeater display are housed, the housing having a first face through which the sensing means may read a display and an opposed second face through which the local repeater display may be read by an operator.

8. A display repeater substantially as described above with reference to the accompanying drawings.