FIELD OF THE INVENTION

The invention relates to an arrangement for controlling the intensity of a physiologically perceptible effect produced by at least one effector means.

The invention also relates to a system for reproducing at least one electrical signal by means of at least one transducer means for converting the electrical signal into a physiological perceptible form, wherein the transducer means cooperates with at least one effector means, wherein the effector means produces an physiologically perceptible effect by changing the electrical signal prior to its reproducing through the transducer means.

The invention further relates to a method of controlling the intensity of a physiologically perceptible effect.

BACKGROUND OF THE INVENTION

The term "effector means" is used in this document instead of "means for producing an effect" to improve the readability of the text.

A physiologically perceptible effect means an effect that can be perceived by a human being. Such an effect can be for instance a smell, an acoustic or a visual effect, a tactile effect etc. There are various effector means for producing a physiological perceptible effect. For instance in the field of sound or video reproduction effector means often appear as so called post processing features for enhancing the reproduction of an audio or video signal. Common post processing features in the field of sound reproduction are for instance bass enhancement features or features for enhancing a stereo sound image of an audio signal.

From the document US 2004/0096068 is known an arrangement, a system and a method as mentioned in the first thee opening paragraph. This document discloses a way of making a reproduction of classical music livelier without decreasing the quality of a reproduction of rock music. This is achieved by automatically amplifying signal components of the audio signal depending on variations of the audio signal to be rendered. Therefore an intensity of the enhancement effect depends only on variations within the rendered audio signal. But it has turned out that many people found this way of providing enhancement effects too artificial and not taking into account their physiological needs or requirements when continuously listening to these sound enhancements effects.

Consequently, with the known device it has proved to be a disadvantage that physiological needs of a user of the device cannot be satisfied.

OBJECT AND SUMMARY OF THE INVENTION It is an object of the invention to provide an arrangement of the type defined in the opening paragraph, and a system of the type as defined in the second paragraph and a method of the type as defined in the third paragraph, in which the disadvantage defined above is avoided.

In order to achieve the object defined above, with an arrangement according to the invention characteristic features are provided so that a device according to the invention can be characterized in the way defined below, that is:

An arrangement for controlling the intensity of a physiologically perceptible effect, wherein the arrangement is arranged for controlling the intensity of the effect depending on the time that has passed since the occurrence of at least one predefined event. In order to achieve the object defined above, with a system according to the invention characteristic features are provided so that a system according to the invention can be characterized in the way defined below, that is:

A system for reproducing at least one electrical signal by means of at least one transducer means for converting the electrical signal into a physiological perceptible form, wherein the transducer means cooperates with at least one effector means, wherein the effector means produces an physiologically perceptible effect by changing the electrical signal prior to its reproducing through the transducer means, and wherein the system comprises an arrangement according to the invention cooperating with the effector means.

In order to achieve the object defined above, with a method according to the invention characteristic features are provided so that a method according to the invention can be characterized in the way defined below, that is:

A method of controlling the intensity of a physiological perceptible effect wherein the intensity of the effect is controlled depending on the time that has passed since the occurrence of at least one predefined event. The characteristic features according to the invention provide the advantage that the intensity of the effect changes in a manner optimized to psychological needs of the users.

The measures as claimed in claim 2 or in claim 12 respectively, provide the advantage that a user gets a clear feedback that a certain event has taken place now, while the intensity of the effect may be reduced after a while to avoid that a user gets annoyed by a

high intensity of the effect.

The measures as claimed in claim 3 or 4 or 13 respectively provide the advantage that a user gets a clear perceptible feedback when switching on or off an effector means.

However, it has proved to be particularly advantageous if the measures of claim 5 are provided. This achieves the advantage that a reproduction of sound or videos is optimized in manner that ensures a very high consumer satisfaction.

The measures as claimed in claim 6 provide the advantage that the needs of an average user when enhancing the reproduction of a bass of an audio signal are met very well. The measures as claimed in claim 7 provide the advantage that a user gets a clear perceptible feedback that the bass enhancement is switched off now.

The measures as claimed in claim 8 provide the advantage that the needs of an average user when enhancing the reproduction of a stereo audio signal are met very well.

The measurements as claimed in claim 9 provide the advantage that a user gets a clear perceptible feedback that the stereo image enhancement is switched off now. The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to these examples of embodiment but to which the invention is not limited.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a system according to the invention in the form of a block circuit diagram.

Fig. 2 shows a time response according to the invention of an effect in the form of a diagram.

Fig. 3 shows another embodiment of a system according to the invention in the form of a block circuit diagram.

Fig. 4 shows a further embodiment of a system according to the invention in the form of a block circuit diagram.

Fig. 5 shows still further an embodiment of a system according to the invention in the form of a block circuit diagram. Fig. 6 shows another time response according to the invention of an effect.

The figures are schematically drawn and not true to scale, and the identical reference numerals in different figures refer to corresponding elements. It will be clear for those skilled in the art that alternative but equivalent embodiments of the invention are possible without deviating from the true inventive concept, and that the scope of the

invention will be limited by the claims only.

DESCRIPTION OF EMBODIMENTS

Fig. 1 shows a system 5 with an arrangement 1 according to the invention for controlling an intensity of a physiologically perceptible effect . The arrangement 1 comprises a control unit 2, which is connected to effector means 3 for producing the effect. The effector means 3 are connected to a transducer not shown in Fig. 1. The transducer converts an electrical signal s2 supplied at an output of the effector means 3 into a physiologically perceptible form, for instance into sound, images, smell, vibration etc. Therefore the effect produced by means of the effector means 3 is physiologically perceptible. The effector means 3 is in general a signal processing algorithm realized by hardware means and/or software means, which algorithm changes a signal si prior to its reproduction through the transducer. Thus the term "effect" means the changes of the input signal si caused by the effector means 3. In other words the effect achieved is the difference between the output signal s2 and the input signal s 1. The effector means 3 can for instance be means for enhancing the reproduction of audio or video signals. Effector means as they are mentioned in the last sentence are well known to those skilled in the art; see for example the document EP 0332266 Bl or the document WO 2000/057 673 Al.

The transducer can for instance be a loudspeaker, a display, a means for producing a smell as disclosed in the document WO 2003/059403 Al or a means for producing a tactile feedback as disclosed in the document WO 2003/079 895 Al. Another transducer means for producing a tactile feedback has become known in connection with the HG 100 gaming headphones of Philips. The HG 100 headphones comprises means for stimulating the neck and the ears to give a tactile feedback during a video game. The production of the effect is controlled by the control unit 2 of the arrangement

1. A current value of a parameter of the effector means 3 that is relevant for the intensity of the output effect e of the effector means 3 is changed by the control unit 2. The parameter can be for instance an amplification factor for the signal si processed by the effector means 3, or the value of a saturation of a color in a video signal, etc. Furthermore the arrangement 1 is arranged for controlling the intensity of the effect e depending on the time that has passed since the occurrence of at least one predefined event. This predefined event can for instance be the beginning or the end of a song (if a next track on a CD is detected) or the inserting of a CD into a CD player etc.

According to a preferred embodiment of the invention the predefined event is the

the switching on or off of the effector means 3.

According to Fig. 2 the arrangement 1 is arranged for controlling the production of the effect e achieved in a such a manner that within a predetermined time interval il after the predefined event (e.g. switching on the effector means 3) the intensity of the effect e is higher than the intensity of the effect e during a following operating time interval i2, i3. This gives the user a clear impression of the the occurrence of the event (e. g. switching on or off the effector means 3).

According to a further embodiment of the invention the arrangement 1 is arranged to control the producing of an effect e' contrary to the effect e achieved with the effector means 3 during a time interval i4 after a further predefined event has taken place (e. g. switching of the effector means) (Fig. 6). The effect e' contrary to the effect e called "anti effect" in the following description is produced by further effector means not shown in Fig. 1 but indicated with the reference numbers 14 and 26 in Fig. 4 or Fig. 5 respectively.

Producing the anti effect e' gives the user a clear impression that the effector means 3 is switched off now. The embodiment mentioned in this paragraph will be described in further detail in the description of the embodiments shown in Figures 4 and 5 and is of specific interest if the effector means 3 is a means for enhancing the reproduction of an audio or video signal.

The terms switching on or off the effector means 3 indicate the point of time at which the production of the effect e starts or stops.

The control unit 2 is preferably realized by means of a suitable programmed micro processor or control circuit.

In a very simple realization of the invention the arrangement 1 can be realized by a conventional computer such as a PC that comprises a suitable program for controlling the effector means 3.

According to an embodiment of the invention the arrangement 1 realized in the form of a PC is connected to a smell generator, for instance via an USB interface. The smell generator can for instance be a device known as a so called "Scent Dome". The Scent Dome operates using similar principles to an inkjet printer cartridge except instead of mixing different colors to get the final result, a variety of scents are combined to release the desired aroma. Immediately after activating the production of a desired smell via an interface of the PC the Scent Dome produces controlled by the PC a high intensity of the desired smell to indicate that the Scent Dome is switched on now. After a while the intensity of the smell (the effect produced) is reduced to a lower level of intensity.

The effector means 3 and the arrangement 1 can in principal be realized within one and the same device too although they are shown as separate devices in Fig. 1.

In Fig. 2 the time is indicated with t and is increasing from left to right, wherein the effect achieved with the system 5 is indicated with e. According to Fig. 2 the intensity of the effect e produced by the effector means 3 is controlled in such a manner that within a predetermined time interval il after a predefined event (e.g. switching on the effector means 3) a maximal intensity of the effect e is higher than a maximal intensity of the effect e during a following operating time interval i3. The level of intensity in the time interval i3 represents an physiological optimal level of intensity for a longer duration of the effect. The intensity of the effect e is reduced slowly during a time interval i2 lying between the time intervals il and i3. This achieves the advantage that a user can get used to the effect e. After the occurrence of a further predefined event (e. g. switching off the effector means 3) the effect e disappears. It is clear that the different levels of intensities in the different time intervals il, i2, i3 depend on the kind of effect e produced. But for realizing the invention it is just of importance that the intensity is controlled in dependency of the time that has passed since the effector means 3 was switched on or off. Although the points in time when the effector means 3 is switched on or off are indicated with the terms "ON" and "OFF" in Fig. 2 and Fig. 6 the terms "ON" or "OFF" respectively indicate in general points of time at which certain predefined events take place. The time response of the intensity of the effect e or e' respectively (the time response of e' is illustrated in Fig. 6) can in principal be predefined, user defined, or program dependent. Program dependent means that the intensity depends on a certain algorithm that dynamically controls the intensity of the effect e, e' depending on the signal reproduced by the system 5 and the time that has passed since the predefined event (e.g. switching on or off the effector means 3) has taken place.

Fig. 3 shows a system 5' for reproducing audio and/or video signals si the system 5' comprises the control unit 2 of the arrangement 1 (not shown in Fig. 3) as described above, rendering means 4 for the reproduction of sound or videos and the effector means 3. The rendering means 4 is for instance a conventional DVD or CD drive. According to this embodiment of the invention the effector means 3 are preferably means for enhancing a bass reproduction when rendering an audio signal or means for enhancing a stereo sound image when rendering a stereo audio signal or means for enhancing the color reproduction of a video signal.

Effector means 3 of the kind mentioned in the last paragraph are well known to

those skilled in the art. For instance, the document WO 1998/021 915 describes an arrangement for enhancing a stereo image of an audio signal. A bass enhancement arrangement is known for example from the document WO 2000/005 763 Al or the document EP 0 546 619 Bl respectively. Means for enhancing the reproduction of color of a video signal are known amongst others for instance from the document EP 0 332 266 Bl .

The control unit 2 is arranged to control the effector means 3 in a manner that the intensity of the effect e increases after switching on the effector means 3 to a maximum and decreases to a lower level for continuous watching or listening after a while as shown in Fig 2. The output signal si of the rendering means 4 is supplied to the effector means 3. The signal si is processed by the effector means 3 and an enhanced signal s2 is supplied to a transducer (not shown) such as a loudspeaker (indicated with the reference number 16, 17 in Fig. 5) or a display. The transducer means convert the electrical signal si into a physiological perceptible form, such as smell or sound, etc.

Furthermore the control unit 2 is, as already mentioned above, arranged for controlling the producing of an anti effect after switching of the effector means 3. To give the user a clear impression of that the effector means 3 is switched off know. After a while after switching off the effector means 3 the original audio or video signal si is supplied to the transducer.

Fig. 4 shows the system 5' of Fig. 3 in more detail, wherein the processed signal si is an audio signal. In this embodiment analog or digital audio signals can be used. When using digital audio signals the components described in the following, such as filters etc., can be realized instead of using hardware means by software means too.

According to this embodiment of the invention a bass reproduction of the audio signal si is enhanced by the effector means 3, wherein the control unit 2 is arranged for increasing the intensity of the effect e after switching on the effector means 3 and suppressing the reproduction of the bass temporarily after switching off the effector means 3.

For realizing this embodiment of the invention the system 5' receives the audio signal si at an input of the system 5'. The signal si is provided by the rendering means indicated with the reference number 4 in Fig. 3. The control unit 2 controls two amplifying means 10, 10'. The amplifying means 10, 10' each change the signals si' si" provided by the enhancing means 3 and the low pass filter 14 according to the formulas: sl"' = k'*sl' and sl""=k"*sl" and 0 < k', k" wherein k' and k" are the respective gains of the amplifying means 10, 10'. The output signal s2 is a linear combination of the signals si, si'" and si"". The control unit 2 changes the values of the gains k' and k" according to a time scheme in

dependency of the time that has passed since the occurrence of a predefined effect (e. g. switching on or off the effector means 3). Thus the intensity of the output signals si '" and si "" of the amplifying means 10, 10' and thus the effect e, e' introduced by the effector means 3 or the low pass 14 depends on the time that has passed since the occurrence of the predefined event.

The effector means 3 will be referred to as "enhancing means 3" in the following description of this embodiment.

The enhancing means 3 comprise band pass filter means 7 for selecting a part of the audio signal si (the low frequency part). The output of the band pass filter means 7 is coupled with a so called non linear device 8 (for example a harmonic generator or integrator etc.). The non linear device 8 is coupled to a low pass filter 9 for filtering out the higher frequency components of the signal provided by the non linear device 8. The output signal of the enhancing means 3 is supplied to the controllable amplification means 10. But according to another embodiment of the invention the amplification means 10 can be integrated to the non linear device 8 too. The output signal of the amplification means 10 is supplied to summing means 11. At another input the summing means 11 receives the original audio signal si. The output signal si'" of the amplification means 10 and the original signal si are recombined in the summing means 11. The output signal s2 of the summing means 11 is supplied to the output of the audio system 5'. The output of the system 5' can be coupled to transducer means such as loudspeaker means, etc.

According to an embodiment of the invention a user can enter via a respective input means, e. g, a button, a touch screen, etc., a command to switch on or off the enhancement means 3. This command is transmitted to the control unit 2. After receipt of this command the control unit 2 increases or cuts off the output signal si'" of the amplifying means 10.

After switching off the enhancing means 3 the gain k' of amplifying means 10 is set to "0" whereas the gain k" of the amplifying means 10' is increased by means of the control unit 2. The low frequencies for example frequencies under 100 Hz are filtered out of the original audio signal si. Filtering out the low frequencies of the signals si by means of the low pass filter 14 produces an anti effect e' contrary to the effect produced by the enhancing means 3. The output signal si"" of the amplifying means 10' is recombined with the original signal si in the summing means 11, wherein the signal si"" is subtracted from the original signal si. The effect e or the anti effect e' achieved corresponds to the output signals of the amplifiers 10, 10' as shown in Figs. 2 and 6. In Fig. 2 e represents the output

signal of the amplifier 10 and in Fig. 6 e' represents the output signal of the amplifier 10'.

Within a time interval i4 immediately after switching off the enhancement means 3 the anti effect e' has a maximal intensity (Fig. 6). After a certain predetermined time interval indicated with i5 in Fig. 6 the control unit 2 switches off the low pass filter means 14 and the original signal si is supplied to the output of the system 5'. That means si = s2. The intensity of the anti effect e' is decreased slowly within the time interval i5 to allow the user to get used to the reduction of the anti effect e' or the switching off of the effect e respectively.

Fig. 5 shows another embodiment of a system 5" according to the invention. According to this embodiment the effector means indicated with 3 in Fig. 3 is designed as means 3' for enhancing a stereo sound image of an audio signal. The means 3' is indicated as stereo enhancement circuit 3' in the following description of this embodiment for processing a left channel and right channel input signals Ri and Li of an audio signal into left channel and right channel output signals Lo and Ro. Furthermore amplifying means 15 for amplifying and supplying the left channel and right channel output signals Lo and Ro to respective left channel and right channel loudspeakers 16, 17. The amplifying means 15 comprises according to a preferred embodiment of the invention a switching functionality and is controlled by the control unit 2'. By controlling the amplifying means 15 the enhancement circuit 3' can be switched on or off. The stereo enhancement circuit 3' comprises first means 18 having a first input for receiving the left channel input signal Li, a second input for receiving the right channel input signal Ri, a first output for providing a left channel signal Ls and a second output for providing a right channel signal Rs. The left and right channel signals Ls and Rs have an enhanced stereo image as compared to the signals Li and Ri. The stereo enhancement circuit 3' further comprises second means for controllably combining the left channel signals Li and Ls and the right channel signals Ri and Rs. The second means comprises:

First and second subtracters 19 and 20 for providing the subtracted pairs of signals Li-Ls, and Ri-Rs, respectively to respective controllable attenuators 21, 22, each having a controllable gain α, wherein 0 < α < 1, first and second adders 23 and 24 for adding the output signal of the first and second controllable attenuators 21, 22 to signals Li and Ri, thereby providing the left channel and right channel output signals Lo and Ro. In this way the output signals Lo and Ro are formed according to the formulas: Lo = α*Ls + (l-α)*Li Ro = α*Rs + (l-α)*Ri

By varying the parameter α between 0 and 1 the stereo effect in the output signal formed by the left and right channel signals Lo and Ro can be varied between a normal conventional stereo image for α = 0 to a fully enhanced stereo image for α = 1. The second means can be implemented in other ways as well, for example by providing separate controllable attenuators for each of the signals Li, Ri, Ls and Rs, having respective controllable gains of (1-α), α and adding the resulting pairs of attenuated signals attenuated signals Li, Ls and Ri, Rs.

After switching on the effector means 3' the control unit 2' changes the parameter α according to a time scheme. This scheme depends on the time that has passed since the effector means 3' was switched on. The time scheme can be, as already mentioned above, predetermined, user defined or program dependent. According to the time scheme the parameter α can for instance be set to the value 1 immediately after switching on the effector means 3'. After a certain time interval il the control unit 2' sets the parameter α to a lower value. Thus the enhanced stereo effect is decreased to a level that is suitable for longer hearing.

After switching off the effector means 3' the control unit 2' switches on a cross talk circuit 26 by means of amplification means 25 connected to an output of the cross talk circuit 26. After switching on the cross talk circuit the left and right channel Li, Ri of the input signal are supplied to a input of the cross talk circuit 26. The output signals Li' and Ri' of the cross talk circuit 26 are formed according to the formulas:

L' = βL + (l-β)Ri

R' = βR + (l-β)Li

With 0,5 < β < l.

For β = 1 the output signal of the circuit 26 is the original signal. For β = 0.5 an exact mono signal is achieved. After switching of the effector means 3' the control unit 2' sets the parameter β on the value 0,5. By means of this the original audio signal is made more mono after switching of the effector means 3'. After a predefined time interval after switching off the effector means 3' the value of β is gradually increased to 1. Thus the anti effect e' is produced by means of the cross talk circuit 26 depending on the time that has passed since the effector means 3' was switched off. After a while after switching off the effector means 3' the original signal is supplied at the output of the system 5'.

It should be marked that for realizing the invention not just stereo channels but any number of audio channels could be used.

The time behaviour of the effect e achieved with the effector means 3' is the

same as shown in Fig. 2 .

According to Fig. 6 the anti effect e' is produced by activating the cross talk circuit 26 after switching of the effector means 3' to give the user a clear impression of that the effector means is switched off know. The term "OFF" in Fig. 6 indicates the point of time when the producing of the effect e is stopped and the producing of the anti effect e starts. After a time interval i4 the producing of the anti effect e' is stopped and the original input signal is supplied to the output of the system 5'. According to a preferred embodiment of the invention the anti effect e' decreases slowly within a time interval i5 after switching off the effector means 3' to give the user the possibility to get used to the reduction of the anti effect e'.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The word "comprising" and "comprises", and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.