Patent No. 5134484 Superimposing method and apparatus useful for subliminal messages

 

Patent No. 5134484

Superimposing method and apparatus useful for subliminal messages (Wilson, Jul 28, 1992)

ASSIGNEE: MindsEye Educational Systems, Inc., Strafford, PA

Abstract

Data to be displayed is combined with a composite video signal. The data is stored in a memory in digital form. Each byte of the data is read out in sequential fashion to determine: the recurrence display rate of the data according to the frame sync pulses of the video signal; the location of the data within the video image according to the line sync pulses of the video signal; and the location of the data display within the video image according to the position information. Synchronization of the data with the video image is derived from the sync pulses of the composite video signal. A similar technique is employed to combine sound data with an audio signal. Data to be displayed may be presented as a subliminal message or may persist for a given time interval. The data may be derived from a variety of sources including a prerecorded or live video signal. The message may be a reminder message displayed upon a television screen to remind the viewer of an appointment. The data may be stored in a variety of different memory devices capable of high speed data retrieval. The data may be generated locally on-line or off-line and transferred to memory which stores the data necessary to create the message.

Notes:

FIELD OF THE INVENTION

The present invention relates to apparatus for combining video signals with additional information, and more particularly to a novel method and apparatus for superimposing messages, graphic information and the like to video signals and/or audio signals and which is uniquely adapted to provide both static and dynamic information for either normal or subliminal presentation.

BACKGROUND OF THE INVENTION

A variety of different applications exist wherein it is desirable to combine information signals. For example, one typical application is the provision of subliminal messages. In order to present a subliminal message upon a television screen, it is necessary to provide apparatus for producing the data in the form of signals which are capable of being processed by a standard television receiver and to synchronize the signals with the R.F. signals being broadcast to the television receiver such as, for example, a transmission from a local or network television station to a television in a viewer's residence.

The transmitted video signal is typically comprised of synchronizing signals, namely, frame and line synchronizing signals also referred to as vertical and horizontal sync signals, respectively. The sync signals are combined with the image information to form a composite video signal which is transmitted to a television receiver by way of a carrier frequency signal which is modulated by the composite video signal.

The modulated carrier is processed at the television receiver to remove the composite video signal from the carrier frequency signal whereupon the video display is generated in accordance with the information signals and the corresponding synchronizing signals.

Heretofore, conventional techniques for displaying information such as messages, graphic and pictorial images and the like, utilize synchronizing signals which are generated specifically for the data to be superimposed, which signals are generated totally independently of the synchronizing signals forming part of the composite video signal.

One such conventional prior art technique is described in U.S. Pat. No. 4,616,261 in which switching means is provided for alternately switching between the composite video signal and the information to be combined therewith. This system has the disadvantages of cutting out the composite video signal during the time that the message, such as a subliminal message, is being introduced, and further requires separate, independent sync signals for the subliminal message, which switching system is thus incapable of precisely synchronizing the subliminal message with the video image as regards its rate of occurrence and precise location upon the screen.

BRIEF DESCRIPTION OF THE INVENTION

The present invention is characterized by comprising a system in which the synchronizing signals for the overlay message are derived from the composite video signal, thus assuring perfect synchronism of the overlay message with the video image and further assuring the precise location of the overlay message according to the desires of the particular application. An overlay message (or messages) may be a subliminal or a persistent image or combinations thereof.

The present invention is characterized by comprising an electronic solid state system in which a memory source which may, for example, be a READ ONLY MEMORY (ROM) contains information relating to the refresh rate, the line position and the location on each line at which the message is to be displayed, as well as information representing the message.

The present invention is characterized by comprising a method and apparatus for extracting a composite video signal from a modulated carrier, extracting the frame and line signals from the composite video signal, examining a memory device in which data representing the frame count, line count and placement information are stored in a predetermined arrangement within the memory whereby a frame count is utilized to initiate the regeneration of message signals and to determine the refresh rate therefor, a line count is utilized to determine the line or lines which are to receive information and the position information is utilized to determine the location of the display data on each line of the video image, as well as the arrangement of the data or message on each line. The line (i.e., line sync pulse) count is extracted from memory and compared with the count of accumulated line sync pulses derived from the composite video signal. When the number of line sync pulses accumulated compares with (i.e. is equal to) the line count extracted from the memory, the line position count is then extracted from memory and the pulses generated by a timing pulse generator are counted and the count of the line position is compared with the timing pulses accumulated from the timing pulse generator. When these two counts compare, the data in the next memory location is extracted, which data represents the display information, and may be in the form of the presence or absence of a dot or the presence or absence of a dot of a predetermined brightness. For each location along the line which is to contain a dot, a dot production signal is combined with the composite video signal to produce a composite video plus message signal which is then preferably modulated with the channel 3 or channel 4 carrier, for example, for coupling to the television receiver for presentation of the video image and overlay message information upon the television screen, which may be a subliminal and/or a persistent message.

Each line making up the television display, which may, for example, be a 525 line screen, is divided into a precise number of data (i.e. dot) positions according to a precision timing pulse generator. The timing pulse generator generates pulses at a rate to precisely create the number of data positions per line, and which is the same for each line. The accuracy of the timing pulse generator is enhanced by automatically restarting the timing pulse generator each time a line sync signal is produced to assure initiation of the first timing pulse with a line sync signal and further to assure that the precise number of pulses are produced for each line making up the video display. Thus, the data on each line is precisely located relative to the left-hand edge of the display screen, for example.

The information to be displayed per line may necessitate a storage capacity of one or a plurality of binary bytes. The bytes are sequentially withdrawn from the memory, which is preferably a READ ONLY MEMORY (ROM), to determine the number of data positions or dots to be "painted" on each line.

When the desired number of dots have been "painted" for a given line, the next byte extracted from memory contains an instruction code which causes the system to wait for the next line sync pulse whereupon the number of bytes necessary to represent the dots to be painted on the next horizontal line are likewise extracted in sequential fashion.

When all of the dots to be painted to complete an image have been combined with the composite video signal, the next byte extracted from memory is a reset code whereby the system is caused to return to the first byte in the memory for the message program. The refresh rate is determined by counting the frame sync pulses and comparing the count against the frame count stored in memory. The frame sync pulse count thus determines the refresh rate, i.e., the rate at which the data is refreshed. The data may be a message, a graphic presentation of either a static or dynamic nature or a combination thereof. The data may be audio in nature as will be described.

In one preferred embodiment, the dots which are "painted" on each line may have a uniform brightness (i.e., presence or absence of a dot of a fixed brightness or illumination level).

Alternatively, each dot may have a brightness level lying within a predetermined range whereby the brightness level for each dot is determined by binary coded data which is converted by means of a digital-to-analog converter to generate a dot of brightness determined by the digital value stored for that dot whose analog value (represented in digital form) falls within a range between a minimum and a maximum brightness. In either case, the dot signal is additive to the composite video signal, always increasing (i.e., never decreasing) the brightness level of the image created by the composite video signal.

Another alternative technique is to create a fixed gray level at the location of each "dot" in place of adding a level to the video signal.

As still another alternative embodiment, the present invention may be utilized to introduce a subliminal audio message to an audio signal. The audio signal may, for example, be recorded on an audio cassette tape or may be broadcast from a remote radio or television transmitter. Upon initiation of tape play or receipt of an RF carrier, a timing pulse generator is activated. A memory is examined to extract the first byte of information representing the refresh rate of the audio message which is refreshed at a rate determined by the count value stored in the binary byte. This count is compared with pulses developed by a timing pulse generator so that, when the accumulated pulses compare with the stored count, the next byte (a message byte) is extracted from memory. The message bytes represent, in binary format, an instantaneous portion of the audio (analog) signal. Each digital value is converted into an analog value and is then combined with the audio signal. The memory stores a number of bytes sufficient to represent each word or sound.

Bytes may also be provided in memory for providing dead intervals between adjacent words or sound, where appropriate.

If desired, the audio signal may be in the form of an AM or FM signal received from a remote transmitter and comprised of a carrier modulated by the audio signal according to either an AM or FM technique. The carrier may be demodulated whereupon the subliminal message, once converted into analog form, is combined with the audio signal whereupon the combined signals may then be used to modulate the carrier frequency for playback by the AM (or FM) tuner.

If desired, the subliminal message may be an audio message superimposed upon the television message. If desired, the audio message may be generated in synchronism with the video (subliminal) message. As an alternative, the audio (subliminal) message may be generated utilizing the refresh rate information employed for generating a subliminal video message. The method and apparatus of the present invention may be utilized to provide an appointment or reminder capability by superimposing a reminder message upon the television display to remind the observer of an appointment, for example, the message data to be superimposed on the video image being stored in memory and comprised of data and instructions similar to those employed for providing a subliminal or perisistent image.

The data to be superimposed may be derived from a variety of sources such as a live television broadcast source, a video composite signal stored in video casette tape or a laser disc or other off-line memories. The data may be generated through the keyboard of a computer, stored in the computer memory and transferred to the memory employed in the apparatus of the present invention, the last-mentioned memory preferably being any memory capable of high speed data storage and retrieval such as ROMs, RAMs, diskettes, laser discs, bubble memories and other like devices.

The system of the present invention is capable of creating an image for one or more fields such as one field or both fields of a frame comprised of two interlaced fields or a succession of fields in cases where a persistent image is desired. This capability is obtained by storing the address of the date to be repeated in a register and returning to the stored address at a rate determined by a count stored in a repetition counter and which is derived from a repeat segment byte stored in memory and comprised of a repeat segment instruction code and a repetition valve.

The subliminal message may be preceded by an introductory frame which may include the title of the message to be presented, the company name and/or logo, or the like. Since it is desired that the introductory frame persist for an interval of at least several seconds, a technique is provided for successively repeating the field of the introductory image a predetermined number of times by initiating an introductory mode and triggering the field counter to repeat the bytes making up the field for a predetermined number of successive frame sync pulses and terminating the introductory mode when the field counter reaches a predetermined count.