DE536597C - Photoelectric musical instrument with fixed phonograms and rotating slit diaphragms - Google Patents

Description

Photoelectric musical instrument with fixed and rotating phonograms Slit diaphragms The invention relates to a musical instrument in which sounds are photoelectric can be generated by means of fixed phonograms.

Devices that operate in a photoelectric manner by means of fixed Phonograms produce sounds are already known. They are made up of opaque Discs with slots that rotate and made up of fixed panels in shape of phonograms. The distance between the slots is adapted to the length of the phonograms. Light directed in parallel is sent through the panes. The rays of light are then continuously controlled in their cross-section according to the phonograms and finally thrown into a light-sensitive cell. There then arise current fluctuations, which are amplified in a known way and made audible as sounds.

A particular advantage of this process over others is that that sounds of different vibration forms, d. see timbres, optionally generated and that no complicated technical effort is required for this. There is only the exchange of small phonograms, one or a few periods are long and are fixed during the sound generation itself.

It has already been suggested to take this advantage in the form of a To make instrument usable that meets the requirements of the practical music business in terms of tempered mood and easy purposes. To this Multiple devices of the mentioned method have been indicated earlier for purposes. The invention now relates to such multiple devices, the discs with Use several rows of slots, as other carriers of the slots, such as. B. endless Belts and the like, because of wear at high speed or because of too large a circumference out of the question.

The invention has set itself the task of creating a multiple device of this type with slotted disks to set up a musical instrument in such a way that it the Exceeds the efficiency of an organ without having its disadvantage consists in the large space requirement and the associated immobility. Included In contrast to known suggestions, special emphasis is placed on the greatest possible Operational safety and noise-free sound generation.

The operational safety largely depends on the functional design of the drive together. The desired range is decisive for the drive. This is usually set to 7 octaves or 84 pitches. The task of one such a range in tempered tuning by means of a number of slotted discs to include, is in the known proposals (also for non-photoelectric working Devices) have been solved differently.

Common to all solutions is the division of the frequency range on a number of slotted disks. Here are the rational within each disc Frequency ratios, d. see the octaves and approximately also fourths and fifths, generated. The irrational conditions which, as is well known, the Frequency steps represent the tempered mood, on the other hand, are achieved by for each pitch (except fourth, fifth and octave) a disc with a different speed used. In this way, the division of the entire area has previously required 12, in the best case 7 slices.

The various proposals also differ in terms of the drive of the discs .. Some use a common drive for all discs Frictional translations, e.g. B. cord drives, friction disks, friction cones o. The like. To thereby the irrational frequency ratio or speed ratio between each to reach two levels or discs. However, these types of translation are inadequate, because at the speeds of 2z76 to -74o per minute required here, one is not permitted severe wear of the parts rubbing against each other must occur. The Associated A reduction in operational safety forces us to do without the common drive.

For this reason, the other known proposals use single drives. It is. It should be noted that the constancy of the speed of each individual drive is high Requirements must be made. The purity of the mood demands accuracy of about Z ° / oo. Expediently, the drive is now electrical, including any existing power network is used. The tensions in the power networks are fluctuations subject, which are transferred proportionally to the speeds of the engines. Since these fluctuations can be up to 10 per cent or zoo per cent and more, so would the permissible speed deviation is exceeded ioomal. This would make the Basic tuning of the whole instrument too high or too low and the purity of the Interaction with other types of instruments can be destroyed. I also have to go for it Care must be taken that the speed ratios between the individual drives remain constant - otherwise the purity within the tempered mood would be clouded. For both reasons there is a need for every drive. to be provided with an automatic, highly sensitive speed controller. But now the smallest number of drives in the known instruments is 7, on the other hand in the present invention only g. The saving of 2 drives represents therefore an advantage.

The reduction in the number of individual drives has already led to to use the slotted disks in such a way that as many frequencies as possible (in rational proportions) can be generated by a disk or a drive. There are large disks with z. B. 12 rows of slots the result. In the present Trap, large disks are unfavorable because the speeds, as will be justified, must be relatively high. The invention therefore uses small discs with only 6 rows of slots. The increased number of frequencies that can be generated per drive then comes due to the fact that, firstly, by one drive instead of one big two small ones Discs are moved; the second disc is thereby activated by means of a gear transmission or the like in the simple ratio of 8: i rotated more slowly. Secondly the number of frequencies that can be generated by a disk is high because the rows of slots are used twice in two respects, as explained below will.

The use of relatively high speeds is justified as follows: Decisive for any disruptions in the continuous flow of the control process of the light beams is the degree of accuracy in which the spacing of the slots corresponds to the lengths of the phonograms to match. This correspondence can initially be disturbed by imprecise Division (spacing of the slots) of the slotted discs. So now the division error If it becomes acoustically negligibly small, it must be small in relation to the slot width - or with the same absolute division error, the disturbance is all the less the wider the slot. For this reason, the slot is as wide as possible to strive for, with the added advantage of facilitated manufacture. broad However, slots require a correspondingly large scale of the periods in the phonograms, because otherwise overtones whose period length is less than four times the slot width is no longer controlled, as is known from optical sound technology. It is therefore advisable to achieve the largest possible scale by having the available length of the phonograms with only one period filled in and use is only made of small multiples in emergencies. In order to the periods or the phonograms themselves can become long, one has the slot spacing as large as possible, so to choose the number of slots as small as possible. The smallest number of slots from which the rest can be built up from row to row on a disc, around with this disc and, for example, the simple period picture at the same time fourth, fifth and octave is 6, followed by 8, g and i2. For example, requires now the lowest frequency of the entire instrument range, that of a row of slots 6 slots have to be generated by means of a single phonogram period a speed of the drive motor of the disc concerned of 2 176 per minute, such as is explained in more detail on the embodiment; the maximum is 2,740 revolutions needed per minute. So relatively high speeds cannot be achieved avoid, if a high degree of continuity of the control process through small disks, wide Slits and long phonograms should be ensured.

According to this, it is now possible to justify more precisely why Particular importance is attached to the smallness of the disks in the present invention. at large panes namely discontinuities of the control process or disturbing tones occur not only due to manufacturing defects in the pitch, but also due to uneven Expansion of the pane material as a result of irradiation by the light sources and by the influence of centrifugal forces in the rapid rotation. One tries, to prevent this by means of sufficiently massive panes, one encourages the emergence of vibrations. But through them the correspondence of the slot spacing and Phonogram length as a result of small movements between the disk and the image in the direction the slots temporally disturbed and also caused a disturbance tone. It is accordingly especially because of this: Basically advantageous to get by with the smallest possible discs.

From what has been said, it follows that the invention in question is a great deal stricter conditions in terms of operational safety and sound generation free of interference accommodates than can be observed with the previously known.

The aforementioned object of the invention, the space requirements of the whole Restricting the instrument in such a way that it is movable leads to the requirement that to use the slotted discs favorably. For this purpose, first, the lengths of the phonograms are made approximately equal to each other. Second, every row of slots exploited several times. As is explained in more detail in the exemplary embodiment, it happens in contrast to the known proposals in such a way that each row of slots a slice of two different, mutually independent phonogram groups, each of which contains a different timbre, is covered at the same time. This takes place within a phonogram group the use of a row of slots also multiple times through sound images that are in an octave ratio to each other.

In the following an embodiment of the invention is based on hand Illustrations explained. It shows: Fig. I and 2 the arrangement of the phonograms, Phonogram carrier and slotted disks in the view, Fig. 3 the arrangement of Fig. 2 in plan with a plan of the pitches for an instrument range of 7 octaves.

The photoelectric devices are not shown.

The embodiment includes a range of 7 octaves or 84 pitches in tempered tuning. A phonogram is assigned to each tone level (pitch). The phonograms are grouped into groups of 24, e.g. B. Group Fl, consisting of the phonograms f 1 to f14 (Fig. I). All phonograms in a group have the same waveform or a corresponding timbre. For example, in fl, f 2, etc. simple sine waves shown, on the other hand at 01, 02 ETC. compound. The entire range of 7 octaves is covered by 5 phonogram groups of the same timbre F ', F2, F3, F4, F5, which form the F series (Fig. 2). The phonogram groups of a series are distributed over the ribbon-shaped supports d2, d4, d6, d8, d1 °. Other groups of phonograms, but with different waveforms (timbres), are housed on the same carriers as standard, e.g. B. the E-series, the G-series and others that are no longer shown.

Between or next to the supports d2, d4, ds, d8, d19 there are still others, namely dl, d3, d5, d ', d9, d11. Phono = grams are also arranged on these and belong to the N-series (N 'to N5), 0-series (01 to 05), P-series (Pl to P5) urw. summarized. In each of these series the phonograms have different waveforms (timbres).

In the further description, the F and the 0 series are described in more detail Keep an eye out. These series work with io slotted disks cl to clo (Fig. 2 and 3) together. They are drawn in the position that they are opposite the slotted disks when the instrument is tuned to its tone. Other timbres are adjusted by moving the carrier as far in the direction of the arrow or vice versa be shifted until the new series take the place of the F or 0 series.

The slotted disks cl to c19 (Fig. 2, in Fig. I only cl to c3 are drawn) are driven by five motors m, namely the disk pairs cl c2, c3 c4, c6 c ';, c7 c8, c9 c19 by one each Motor driven. The disks c2, c4, cs, c8, c1 ° are set in rotation immediately, whereas the disks cl, c3, c5, c ', c9 are set in rotation according to the invention indirectly by gear ratios z or the like more slowly, for example in a ratio of 8: i .

The phonogram carriers dl to d11 (Fig. 2 and 3, in Fig. I are only d2 and d3 drawn) are parallel to each other in one plane and cover all of them Discs, so that each carrier is the halves of two adjacent discs covered and collaborated with them; on the other hand, each disc works with two different carriers together. It covers z. B. the carrier d2 the disks cl and c2 each half, and the disk c2 works simultaneously with the two carriers dl and d2 together.

Due to this arrangement, the io slotted disks are used in such a way that that the two phonogram series F and 0 can be heard at the same time, So that two different timbres can be produced at the same time, or only any of them as you want.

Each disc has 6 concentric rows of slots s' to s6 (Fig. i) with 6, 8, g, 12, 16 and 18 slots. The phonogram group F 'now works with it the pair of disks cl c2 together. The 24 phonograms in this group are distributed in such a way that that there are two phonograms for each row of slots; z. B. work with the two Rows of slits sl in disk c2 and cl, the phonograms f1, f 'and f13, fls together.

The 24 phonograms of the group Fl-differ partly in the Number of oscillation periods shown in a phonogram, as shown in Fig. I on the basis of drawn simple sinusoidal oscillations can be seen and still is detailed. The phonograms fl to fl2 are similar to those from f13 to f24 Completely; they are only twisted 18o 'to f13 to f211 and summarized over this set.

The phonogram groups F2 to F5 are congruent to group F1. The E, G, N, 0, P etc. Series have the same arrangement of the periods of oscillation in their phonogram groups as the F series. As can be seen from Fig. 2, the N, 0, P etc. series are used to encompass the entire range. six beams are required instead of five for the E, F, G, etc. series. A carrier appears to be halved so that the outer halves of the disks cl and cll can be used.

The following is characteristic of the inventive use of a slotted disc: Each row of slits is used several times by the phonograms of two different timbres, e.g. B. the series s' of the disk c2 through fl, f 7 and o13, o13 (Fig. I), where fl, f 7, for example, as already mentioned, contain simple sinusoids o13, oll some compound waveform. Within each timbre, the utilization takes place through two phonograms, e.g. B. by f 1 and f 7 or o13 and o19. The oscillation periods of two phonograms of the same timbre and row of slots are in an octave relationship to one another; z. B. the phonogram f 1 has two and f 7 one period and o13 two and o19 one period.

As already mentioned at the beginning, one generally strives to create as many pitches as possible with a disc. In the solutions known up to now, however, there was above all the disadvantage that the phonograms for those frequencies which are furthest apart have a very unequal length and consequently neither the disks nor the light sources are well utilized. The present invention works with an advantageous compensation of the phonogram lengths in the case of sound frequencies of very different sizes. This compensation is brought about on the one hand by the arrangement that, according to the invention, the phonogram period, which is the same for 3 rows of slots, is also doubled for the three outer rows with a doubled number of slots; z. B. the phonograms fl, f2, f3 belonging to the rows sl, s2, s3 of the disk c2 each have two periods, the phonograms f4, f5, f6 belonging to the rows s4, s5, s6 of the same disk each have four periods, and the Phonograms assigned to the disc cl have one or two periods in the corresponding positions.

In connection with this, on the other hand, the lengths of the phonograms for very different sound frequencies are made almost equal to each other by the fact that the disk cl rotates eight times slower than c2. As is to be explained in more detail, is z. B. generated by the phonogram f s a frequency that is about a hundred times greater is than that evoked by f1-9; but both phonograms are approximated of equal length.

The cooperation of the slotted disks and phonograms is through the table below made clear. All factors are compiled in it, which are decisive for the formation of the different pitches. The columns 1I to V apply to all phonogram groups, while columns 1, VI and VII only apply to the groups connected to the pair of disks cl c2, specifically in the case shown Fl.

The individual tone frequencies come about as follows: The phonogram fl works together with disk c2 and its row of slots s', the six slots owns. With one rotation of the disk c2, the phonogram becomes six times steers through. Since the phonogram fl consists of two periods of oscillation, see above become 6. 2 = i2 periods (column V) generated. If the disk c2 2 rotates 176 times per minute or 36.- 67 times per second, so result, since 12 oscillation periods are controlled during each revolution, 12 -36.267 = 435 Hertz.

In a corresponding manner, the pitches of the phonograms f 13 to f 24 are determined by disk cl. It should be noted that this disk rotates eight times slower than e2. To simplify the calculation, those frequencies controlled by the rows of slots in the disk cl are given in column V which arise during one revolution of the disk c2. These numbers are eight times smaller than those belonging to disk c2 itself.

In column VII, finally, the pitches are listed which correspond to the frequencies calculated in column VI. The chamber tone a (crossed) with 435 Hertz is denoted by a °, the higher octaves of a ° with a- + 1, a + 2 and the lower octaves with a-1, a-2, a-3, a -4. According to the usual naming, a-4 is in the subcontractave, a-3 in the contract octave that extends from c-3 to b-3, etc. I II HI IV V VI VII Phono slot slot period frequency hl id per revolution frequency pitch gram series number number from c- in Hertz Disc c ' fi si 6 2 12 435.0 a ° f2 s2 8 2 16 58o, 6 d + i f3 S3 9 2 18 - 651.8 e + ' f4 s4 12 4 48 1740.0 a + 2 f5 s5 16 4 64 239-2.4 d + 3 f 6 s 6 1 8 4 72 2607.2 e + 3 f7 si 6 1 6 217.6 ai f $ s2 8 1 8 29 0 , 3 do f9 s3 9 1 9 3259 e 0 f10 s4 12 2 24 870, o a + l f11 ss 16 2 32 1 161.2 d + 2 f12 s 6 18 .2 36 1 303.6 e + 2 Disc cl f13 sl 6 2 1.5 544 a-3 f14 S2 8 2 2 72.6 d -2 f15 s3 9 2 2.5 81.7 e-2 f 16 s4 12 4 6 217.6 ai f 17 s5 16 4 8 290.3 do fis s 6 18 4 9 3259 e 0 fig Si 6 1 0.75 27.2 a-4 f20 s2 8 1 1 36.3 d-3 f 21 s3 9 1 1 , 1 25 4o, 8 e-3 f 22 s4 12 2 3 = 09, o a-2 f 23 s5 16 2 4 145.2 d-1 f24 s 6 18 2 4.5 163.5 For the remaining phonogram groups FZ to F5 and the associated disk pairs, the same relationships exist between slot numbers and phonograms (columns II to V), only the pitches generated are different. These are determined by the different speeds of the motors in such a way that each pair of disks is driven 1 = 1/2 times faster than the previous one. As a result, in group F2, phonogram fl, instead of a °, the next higher pitch according to the tempered tuning, i.e. b °, is generated; all other pitches of the disc pair c3 c4 increase accordingly. In the following groups F3, F4, F5 the phonogram f i then gives ho, c-1, cis + l. Think of phonogram groups Fi, F2, F3, F4 and F5 appropriate. In addition to these carriers or groups, the pitches that can be generated by them are written down as they correspond to the position of the phonograms f 1 to f 24 in each of the five groups.

The tone range of 7 octaves shown in the exemplary embodiment is sufficient from a-4 to g sharp + 3. These limits can be shifted in parallel when the speeds the motors can be changed accordingly.

So for the musical purpose of the instrument the individual tones can be generated in any order, are, as already suggested by another side, Shutters v (Fig. 3) are provided. The rays of light will for usually somewhere, e.g. B. after being controlled by the phonograms have been, by means of as many apertures v as there are phonograms or pitches there, interrupted. When the aperture is opened, the conversion of the light impulses takes place accomplished in sounds. The panels are operated using a keyboard t. The connection of the buttons with the bezels v, which is accomplished mechanically or electrically is indicated in Fig. 3 by lines; it was for the purpose of; better Overview for two tones in octave ratio only one connecting line drawn.

The keyboard t is used to make music on the type of organ, for example with the phonograms or tones or sounds of the F series. Simultaneously with this but there is also another, such as the 0 series, ready for production in front of the slotted discs, so that a second tone scale of the same 84 steps in a different tone color to the Available; A keyboard can also be provided for these, which is included in the Drawing is not specified. The remaining existing phonogram group series or timbres are, as already described, by moving their carriers Wish set what z. B. can be done in a similar way to pulling organ stops can.

The volume can be regulated electrically; the one to be changed Resistance is conveniently operated by the feet.

Claims (2)

PATENT CLAIMS: i. Photoelectric musical instrument with fixed phonograms and rotating slotted disks, characterized in that the slotted disks are driven in pairs by one motor each and thereby with different, by gear ratio o. The like. Fixed speeds run that each row of slots due to several phonograms in octave ratio, both identical and different Tone color is used at the same time, and that the doubling of the number of slots a doubling of the period numbers of the phonograms is also assigned to each disc is. 2. Apparatus according to claim i, characterized in that by means of a and the same instrument has two identical tone ranges covering the entire range different timbres at the same time and independently playable thereby be achieved that the associated phonograms for a range and a timbre are arranged on a number of carriers and each carrier with the adjacent halves two jointly driven disks work together, while the other Area and a different tone color equally assigned carrier accordingly work together with the adjacent halves of two disks that are not driven together.