US3831303A

US3831303A - Symbol indication device

Info

Publication number: US3831303A
Application number: US00285433A
Authority: US
Inventors: T Funaki
Original assignee: Sankyo Seiki Manufacturing Co Ltd
Current assignee: Nidec Instruments Corp
Priority date: 1971-10-06
Filing date: 1972-08-31
Publication date: 1974-08-27
Anticipated expiration: 1991-08-27
Also published as: DE2243082C3; CH594199B5; CA979648A; DE2243082A1; DE2243082B2; CH1279972A4

Abstract

A device comprising a mask plate having formed therein at least one symbol indication window comprising at least one relatively narrow and elongated quadrilateral slot or slit and having an inclined base line, a symbol indicator having at least one series of symbol patterns printed or otherwise superposed thereon, and symbol indicator drive means. The symbol indicator drive means intermittently drives and moves the symbol indicator in such manner that the latter is moved a distance corresponding to one half the length of each symbol pattern each time it is driven, whereby one symbol after another can be indicated through the symbol indication window.

Description

United States Patent [191 Funaki [111 3,831,303 [451 Aug. 27, 1974 1 SYMBOL INDICATION DEVICE [75] Inventor: Takashi Funaki, Nagano, Japan 22 Filed: Aug. 31, 1972 21 App]. No.: 285,433

[30] Foreign Application Priority Data Nov. 18, 1971 Japan 46-91904 Dec. 25, 1971 Japan 47-1066 Jan. 14, 1972 Japan 1 47-5863 Jan. 14, 1972 Japan 47-5864 Jan. 28, 1972 Japan 47-9803 7 Sept. 2, 1971 Japan 46-78885 [52] US. Cl. 40/28 C, 58/125 C, 235/117 [51] Int. Cl. G09f 11/00 [58] Field of Search 40/28 C, 68, 77.4, 77.6, 40/777, 77.8, 77.9, 96, 96.5; 235/117; 58/125 C, 127 R [56] References Cited UNITED STATES PATENTS 2,585,420 2/1952 Ailes 40/774 3,292,289 12/1966 Fuhr 40/96 3,344,544 10/1967 Hellen 40/68 3,399,474 9/1968 Rinder 40/28 C 3,200,396 8/1965 Stevens etal 340/378 R 3,444,552 5/1969 Feign 340/378 RX Primary ExaminerWm. H. Grieb Attorney, Agent, or FirmMcG1ew and Tuttle ABSTRACT A device comprising a mask plate having formed therein at least one symbol indication window comprising at least one relatively narrow and elongated quadrilateral slot or slit and having an inclined base line, a symbol indicator having at least one series of symbol patterns printed or otherwise superposed thereon, and symbol indicator drive means. The symbol indicator drive means intermittently drives and moves the symbol indicator in such manner that the latter is moved a distance corresponding to one half the length of each symbol pattern each time it is driven, whereby one symbol after another can be indicated through the symbol indication window.

11 Claims, 20 Drawing Figures PATENTfnAuszmu Hill 7 FIG.

PATENTLUAUGZTIGH SHEUZOF'! FIG.4

FIG.5

PATENTEDmszmm EURO? 7 FlG.IO

PATENTED AUS 2 71974 SHEET 5 0F 7 FIG. l3

FIG.I2

PATENTEDAUBZYIQH 3.831.303

sum am 1' FIG. I5

PATENTEDMIBZTIHM SIB-INF? FIG. I9

FIG. 20

SYMBOL INDICATION DEVICE BACKGROUND OF THE INVENTION This invention relates to a symbol indication device.

In clocks of the digit indication type, it is required to indicate one numerical symbol after another or one day of the week after another as time elapses. In metersof other instruments, it is required to indicate one numerical symbol after another or one letter after another depending on the use to which it is put. It has hitherto been customary to employ various types of symbol indication devices in these apparatus.

In one type of symbol indication devices known in the art, there are provided a mask plate formed threin with at least one symbol indication window which comprises at least one slit or slot, a symbol indicator having at least one series of symbol patterns, and symbol indicator drive means. The symbol indicator is intermittently driven and moved by the symbol indicator drive means in such manner that each symbol pattern is moved a distance corresponding to its length so that the symbols can be indicated successively through one of the symbol indication windows.

The symbol indicator is usually in the form of a drum, or cylinder, or a belt on which at least one series of symbols patterns are printed or otherwise superposed. The symbol indicator of this type is relatively easy to drive. Thus, symbol indication devices using this type of symbol indicator offer the advantages of being more compact in size and lower in production cost than other symbol indication devices such as, for example, those using blades.

When it is required to increase the size of symbols indicated by a symbol indication device using a mask plate and a symbol indicator, there is a disadvantage in that the diameter of the drum or the length of the belt serving as the symbol indicator should be increased. This increases the dimensions of the device.

Stevens, et al., US. Pat. 3,200,396, issued Aug. 10, 1965, discloses drums carrying a series of characters, such a numbers, letters or combinations of letters and numbers. In the Stevens, et al. patent, portions of some adjacent symbols are common to both adjacent symbols, so that the symbol displayed in a display window is composed of two immediately adjacent symbols having overlapping portions in common with each other.

SUMMARY OF THE INVENTION An object of this invention is to provide a symbol indication device comprising a mask plate and a symbol indicator which permits to increase the size of symbols indicated through the window without increasing the dimensions of the device by arranging a plurality of series of symbol patterns on the symbol indicator in such manner that one-half portions of the adjacent symbol patterns ofone series overlap one another and intermittently moving the symbol indicator relative to the mask plate a distance corresponding to one half the length of each symbol pattern whereby one symbol after another can be indicated through one of the windows.

In the present invention, a symbol indication window or windows formed in the mask plate and each comprising at least one relatively narrow and elongated quadrilateral slot or slit and one or a plurality of series of sumbol patterns printed or otherwise superposed on the symbol indicator have respective base lines which are inclined, so that the symbols indicated through the windows are in an inclined position. This is one of the features of this invention. That is, by arranging the symbol indication window or windows and the series of symbol patterns in an inclined position, it is possible to indicate the symbols clearly and definitely, to increase the size of the symbols without increasing the dimensions of the symbol indicator, and to reduce the dimensions of the symbol indicator when it is not nessesary to increase the size of the sumbols, even if one-half portions of the adjacent symbol patterns in the series overlap one another.

As distinguished from the Stevens, et al. patent mentioned above, in the present invention each symbol pattern is completely independent of each other symbol pattern, even though the symbol patterns are made to overlapeach other. Thus each symbol pattern is displayed indendently in the symbol indication window and is complete in and of itself and is not formed by overlapping portions of two adjacent symbol patterns.

Another object of the invention is to provide a symbol indication device of the type described which permits to preclude a visual noise or disturbance represented in the form of a dot or dots or a broken portion or portions in the indicated symbols which is caused by the fact that one-half portions of the adjacent symbol patterns overlap one another. In the present invention, the occurrence of such noise is precluded by refraining from arranging the adjacent symbol patterns to overlap one another and moving the symbol indicator a distance corresponding to the length of one symbol pattern at a position in which a noise tends to occur.

Another object of the invention is to provide a symbol indication device of the type described which proposes to obviate the problem of occurrence of a noise by utilizing a polarizing filter or other polarizer.

Still another object of the invention is to provide a symbol indication device of the type described which comprises a noise preventer interposed between the mask plate and the symbol indicator, such noise preventer being adapted to be disposed in a noise occurring position at a required time so as to prevent the occurrence of a noise.

Still another object of the invention is to provide a symbol indication device of the type described which is effective to prevent ommission of the rightwardly projecting portion of the horizontal member of the numerical symbol 4, when such symbol is indicated by the device, by means of a special arrangement made in one of the symbol indication windows of the mask plate and a background pattern provided on the symbol indicator.

A further object of the invention is to provide a symbol indication device of the type described in which the mask plate, formed with symbol indication windows, is produced by punching from a metallic plate, and connecting portions of the slots of the window are arranged to shield noise producing portions of a symbol pattern on the symbol indicator whereby the provision of the connecting portions of the window can prevent further occurrences of a noise.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a clock of the digit indication type comprising one embodiment of this invention;

FIG. 2 is a left side view of the clock of FIG. 1 with certain portions thereof being broken away;

FIG. 3 is a front view of one form of the mask plate according to this invention;

FIG. 4 is fragmentary developmental view showing the construction of one form of the symbol indicator according to this invention and the manner in which each symbol pattern of the symbol indicator is disposed relative to the mask plate;

FIG. 5 is a plan view of the symbols obtained by watching the symbol patterns on the symbol indicator shown in FIG. 4 through one of the windows in the mask plate shown in FIG. 3;

FIG. 6 is a fragmentary front view of a modified form of the mask plate;

FIG. 7 is a fragmentary developmental view showing a form of the symbol indicator provided with a series of symbols corresponding to the mask plate shown in FIG. 6 and the manner in which each symbol pattern of the symbol indicator is disposed relative to the mask plate;'

FIG. 8 is a plan view of the symbols obtained by watching the symbol patterns on the symbol indicator shown in FIG. 7 through the mask plate shown in FIG.

FIG. 9 is a fragmentary developmental view of another modified form of the symbol indicator according to this invention, showing the manner in which each symbol pattern of the symbol indicator is disposed relative to the mask plate;

FIG. I0 is a side view of the drive means for the symbol indicator;

FIG. II is a plan view of the symbols obtained by watching the symbol patterns or the symbol indicator shown in FIG. 9;

FIG. 12 is a fragmentary front view of a modified form of the mask plate according to this invention;

FIG. 13 is a fragmentary developmental view of another modified form of the symbol indicator corresponding to the mask plate shown in FIG. 12 showing the manner in which each symbol pattern of the symbol indicator is disposed relative to the mask plate;

FIG. 14 is a plan view of the symbols obtained by watching the symbol patterns on the symbol indicator shown in FIG. 13 through the mask plate shown in FIG. 12;

FIG. 15 is a perspective view of noise prevention means and drive means therefore according to this invention;

FIG. 16 is a front view showing the manner in which the noise prevention means shown in FIG. 15 operates;

FIG. 17 is a fragmentary developmental view of a modified form of the symbol indicator adapted to cooperate with the noise prevention means shown in FIG. 15;

FIG. 18 is a fragmentary front view of still another form of the mask plate according to this invention;

FIG. 19 is a fragmentary developmental view of still another modified form of the symbol indicator corresponding to the mask plate shown in FIG. 18, showing the manner in which each symbol pattern of the symbol indicator is disposed relative to the mask plate; and

FIG. 20 is a plan view of the symbols obtained by watching the symbol patterns on the symbol indicator shown in FIG. 19 through the mask plate in FIG. 18 and the manner in which each symbol pattern of the symbol indicator is disposed relative to the mask plate.

DESCRIPTION OF PREFERRED EMBODIMENTS In FIG. 1, there is shown a clock of the digit indication type incorporating therein the present invention. It is to be understood that the invention can have application in apparatus in which letters and numberical symbols are required to be indicated, in addition to clocks. The clock comprises a case 1 having secured to its front side a cover 2 made of glass, plastic or other transparent material, and a mask plate 3 made of metal or plastic.

In FIG. 3, the mask plate 3 is shown as being formed therein with four

symbol indication windows

4a, 4b, 4c and 4d each having an upright base line 0 disposed in an inclined position. It will be seen that while the window 4a comprises only one inclined upright relatively narrow and elongated quadrilateral slot, the

windows

4b, 4c and 4d each comprise three horizontal slots and two inclined upright slots disposed on opposite sides of the horizontal slits. The invention will be described as using the

windows

4b, 4c and 4d which will be referred to as windows 4.

A symbol indicator 5 shown in cylindrical form in FIG. 2 is made of plastic or other transparent material and has a series of symbol patterns 6 representing the

digits

1, 2, 3, 4, 5, 6, 7, 8 and 9 printed or otherwise superposed on its peripheral surface. The series of symbols patterns 6 are shown in developmental form in FIG. 4. Although only one series of symbol patterns is shown in FIG. 4, it is to be understood that actually the number of series of symbol patterns superposed on the symbol indicator 5 corresponds to that of the window 411 and windows 4 in the mask plate 3. The symbol indicator 5 is disposed rearwardly of the mask plate 3 as shown in FIG. 2 and adapted to be driven angularly intermittently by suitable means as subsequently to be described.

A series of symbol patterns 6 cooperates with one of the symbol indication windows 4 of the mask plate 3 to indicate symbols. The base line of each symbol pattern is inclined in the same manner as that of each window 4, so that each symbol pattern is disposed in one section of the symbol indicator 5 corresponding to one of the windows 4. It should be noted that the series of symbol patterns is arranged on the symbol indicator 5 in such manner that the upper portion of the first symbol pattern in the series overlaps the lower portion of the second symbol pattern whose upper portion overlaps the lower portion of the third symbol pattern and so on and so forth. Thus, one-half portions of the adjacent symbol patterns in theseries overlap one another.

In FIG. 4, a solid line bar or bars of each symbol pattern serve to fill the portions of the slots of the window which are not required to indicate the respective symbol while a broken line bar or bars correspond to the portions of the slots of the window which are used to indicate the respective symbol. The broken line bars are phantom lines and are not actually printed on the symbol indicator.

All the symbols can be indicated in the window as negative or positive symbols. When the symbols indicated are referred to as being negative symbols, it is meant that the symbols seen through the window are lighter in color than the surface of the mask plate.

When the symbols indicated are referred to being positive symbols, it means that the symbols are darker in color than the surface of the mask plate. When it is desired to indicate any symbol as a negative symbol, those portions of the slots of the window which are not required for indicating the respective symbol are filled and lost to view by the solid line bars of the respective symbol pattern which are painted in the same color as the surface of the mask plate. Conversely, when it is desired to indicate any symbol as a positive symbol, those portions of the section of the symbol pattern on the symbol indicator which correspond to the broken line bars in FIG. 4 corresponding to the portions of the slots of the window which are required for indicating the respective symbol are painted in a color darker than that of the surface of the mask plate.

When the symbol indicator 5 is driven intermittently by one pitch (through 36, for example) as by clockwork, digits as shown in FIG. 5 can be indicated in the window 4 by the symbol indicator 5 cooperating with the mask plate 3. Imaginary center lines a, b, g of sections of the symbol indicator 5 are successively brought into index with the imaginary center line of one of the symbol indication windows 4, of the three horizontal slits and two inclined upright slots type, in the mask plate 3 as the symbol indicator 5 is intermittently driven and moved. As a result,

digits

1, 2, 3 7 are successively indicated in this order in the window 4 as the portions of each symbol pattern painted in the same color as the surface of the mask plate 3, or the solid line bars, fill those portions of the slots not required for indicating the symbols and shield them from sight.

The clock of the digit indication type shown in FIG. 1 has a lamp built in the symbol indicator 5 so that the time can be readily indicated and perceived even in the dark at night because the digits can be seen in sharp relief. When illuminated from outside the symbol indicator 5, the symbol indicating window 4 disposed in an inclined position may be formed in the mask plate 3 as shown in FIG. 6 to comprise three horizontal slots and four inclined upright slots, and the portions of the surface of the symbol indicator 5 which are required for indicating the symbols may be painted with a fluorescent paint to provide the symbols patterns 6 as shown in FIG. 7. By this arrangement, it is possible to give indication of digits as shown in FIG. 8.

While the invention has been shown and described as being incorporated in a clock of the digit indication type, it will be understood that many of the English letters such, for example as C, E, F, H, I, J, L, O, P and S can be indicated readily as can be surmised from the fact that the letters and l are similar to the digits 0 and l and that the letter E can be indicated by inverting the digit 3.

The surface of the symbol indicator in cylinder form is shown in developed form in FIG. 4. It will be appreciated that an indicator that can be developed in this way, or a belt. for example, can be used to indicate symbols in the same manner as the cylindrical indicator is used in the present invention. It will also be appreciated that the symbol indication windows 4 for indicating numerical symbols, English letters or other symbols are not limited to the type comprising three horizontal slots and two inclined upright slots and that many other types of windows can be employed.

As aforementioned, according to this invention, at least a series'of symbols is superposed on the surface of the indicatorS in the form of a cylinder or a belt in such manner that one-half portions of the adjacent symbol patterns overlap one another. This offers the advantage of being able to indicate the symbols in a size which is twice as large as would be the case if the adjacent symbol patterns on the symbol indicator did not overlap one another.

However, some disadvantage is associated with the arrangement in which inclined symbol patterns 6 are arranged such that they overlap one another and are disposed equidistantly as shown in FIG. 4. More specifically, the symbols as seen through the window 4 will have broken portions in them as seen in the

digits

2, 3, 5, 6 and 0 shown in FIG. 5, or redundant dot or dots in the

digits

1, 2 and 4 shown in FIG. 8. These defects in the indicated symbols constitute a visual noise which looks strange tothe viewer.

The noise in the form of broken portions of the indicated digits occurs in

portions

6A, 6B, 6C, 6D and 6E shown in FIG. 4. It will be observed that these broken portions occur in portions of the symbol patterns where the solid line bar of one symbol pattern and the broken line bar of another symbol pattern, which are disposed in adjacent overlapping relationship, cross each other. The occurrence of a noise can be precluded by several means according to this invention.

In order to obviate the aforementioned disadvantage, the symbol patterns 6 can be arranged in an inclined position on the surface of the symbol indicator 5 in such manner that the adjacent symbol patterns overlap one another unequidistantly as shown in FIG. 9.

More specifically, the symbol indicator 5 shown in FIG. 10 is rotatably supported by a rotary shaft 7 and has a star-shaped cam plate or ratchet 8 integrally connected to one side thereof. The symbol patterns 6 are peripherally superposed on the outer periphery of the symbol indicator 5 in an inclined position in such manner that the adjacent symbol patterns overlap one another unequidistantly as shown in FIG. 9. Wedgeshaped cutouts 9 are formed at one end of the outer periphery of the indicator 5 to receive therein a keep lever 10 so as to regulate the position of angular rotation of the symbol indicator 5.

A sickle-shaped lever or pawl 11, which is supported by a shaft for pivotal movement, is urged by a spring 13 to pivot clockwise be held stationary by a fixed pin 14. A rotary disk 15, which is angularly rotated by a clockwork, has attached to one end thereof a plurality of pins 16 which are spaced different radial distances from the center of the disk 15 but disposed angularly adjacent one another with respect to the center of the disk 15. The pins 16 are engaged by a projection 11a formed in the lever 11.

When the rotary disk 15 is rotated angularly intermittently counter clockwise by the clockwork, one of the pins 16 presses against the projection 11a in the lever 11 and causes the lever to pivot counter clockwise against the biasing force of the spring 13. This results in a front end 11b of the lever pressing the cam plate 8 so as to angularly rotate the symbol indicator 5 counter clockwise.

Since the symbol patterns 6 are arranged to overlap one another and disposed unequidistantly from one another on the outer periphery of the symbol indicator 5 as aforementioned, it is required to change the angle of intermittent rotation of the symbol indicator in order to bring each symbol pattern 6 into index with the symbol indication window 4. This change is effected by the arrangement of cam plate 18 and pins 16. Since the pins 16 are disposed unequidistantly from the center of rotation of the rotary disk 15, the angle of pivotal movement of the lever 11 caused by the intermittent angular rotation of the rotary disk 15 varies each time the rotary disk 15 rotates. The cam plate 8 is formed on its outer periphery with projections 8a which are disposed unequidistantly from one another and in accord with the pivotal movements caused by the pins 16 on the rotary disk 15. By this arrangement, the symbol indicator 5 can be rotated angularly to bring one symbol 6 after another into index with the symbol indication window 4 each time the rotary disk 15 is rotated.

Thus, if the symbol indicator 5 is watched by the viewer through the symbol indication window 4, symbols as shown in FIG. 11 can be seen in the symbol indication window 4, and no visual. noise caused by the breaking of the figures or addition of an unnecessary dot or dots occurs such as seen in

the'digits

2, 3 shown in FIG. 5.

The aforementioned disadvantage associated with the arrangement in which the inclined symbol patterns 6 are arranged such that they overlap one another and are disposed equidistantly from one another as shown in FIG. 4 is thus obviated by arranging the inclined symbol patterns such that they overlap one another but are disposed unequidistantly from one another and driving the symbol indicator angularly intermittently with irregular intervals. It is to be noted that, irrespective of whether the symbol patterns are disposed equidistantly or unequidistantly from one another, the indication device according to this invention permits each symbol to be indicated through the window in a size which is twice as great as would be the case if the symbol patterns were not caused to overlap one another without increasing the dimensions of the device. Besides, the indicated symbols are free from any visual noise, thereby permitting the indicated symbols to be seen more clearly and readily.

The aforementioned disadvantage can be obviated by other means. That is,'the disadvantage can be obviated optically by using polarizers. It will be needless to say that light in a transverse wave motion, and that natural light is a transverse wave motion and consists of vibrations taking place in all directions at right angles to the direction of its path. When natural light is passed through an artifical polarizing plate or the like, it is possible to botain plane polarized light consisting of vibrations in only a specific direction which is at right angles to the direction of its path. Means for converting natural light into plane polarized light. such for example as an articifial polarizing plate. is referred to as a polarizer. A plane comprising the direction of the path of plane polarized light and the direction of its vibrations is referred to as a polarization plane. Plane polarized light has a property such that it passes through a polarizer having a polarization plane which is parallel to its polarization plane but not through a polarizer having a polarization plane which is perpendicular thereto.

According to the invention, four polarizers 17A1, 17A2, 1781 and 1782 are mounted as shown in FIG. 12 in the portions of the slots of the window of the mask plate 3 which correspond to the

portions

6A, 6B,

6C and 6D of the symbol patterns on the symbol indicator in FIG. 4 while five polarizers 18A1, l8A2, 18A3, 1881 and 1882 are mounted as shown in FIG. 13 in the

portions

6A, 6B, 6C, 6D and 6E of the symbol patterns on the symbol indicator 5. It will be noted that, since the

portions

6D and 6E overlap one another, only four polarizers need be mounted in the corresponding portions of the slots of the window.

The polarizers are mounted such that the polarizers 17A1 and 17A2 and the polarizers 18Al, 18A2 and 18A3 have polarization planes which are parallel to one another, and the polarizers 17B1 and 17B2 and the polarizers 1881 and 18B2 have polarization planes which are parallel to one another, but the polarization planes of the polarizers 17A1 and 17A2 and the polarizers 1781 and 1782 are perpendicular to one another (and the polarization planes of the polarizers 18A1, 18A2 and 18A3 and the polarizers 1881 and 18B2 are perpendicular to one another too).

When the indicator 5 having the polarizers 18 mounted in the

portions

6A, 6B, 6C, 6D and 6E of the symbol patterns thereof is rotated anularly intermittently as by clockwork, center lines (a), (b) (g) of the symbol patterns on the symbol indicator 5 successively are brought into index with the center of the window 4 in the mask plate 3, permitting the

digits

1, 2, 3 O to be indicated successively through the window as shown in FIG. 14.

Let us assume that it is desired to indicate the digit 1 in the window, for example. In this case, the center line (a) of the symbol pattern on the symbol indicator 5 shown in FIG. 13 is indexed with the center of the window 4 shown in FIG. 12. In the portions of the slots of the window 4 where the polarizers l7Al, 17A2 and 1782 are mounted, natural light is converted into plane polarized light but this has no effect on the viewer who watches the indicated digit. However, in the portion of the slots of the window where the polarizer 1782 is mounted, the polarizer 17B2 overlies the polarizer 18Al mounted in the portion 6A of the symbol pattern 6 on the symbol indicator 5 and light is intercepted by them because the polarization surfaces of these polarizers are perpendicular to one another. Thus, the flawless digit 1 shown in FIG. 14 can be seen through the window.

If the symbol indicator 5 is angularly moved and the center line (b) of the symbol indicator 5 shown in FIG. 14 is indexed with the center line of the window in the mask plate 3, then the portions of the slits of the window 4 in which the polarizers 17A2 and 1782 are mounted have no effect on the viewer watching the device, but the polarizer 17Al in the slit of the window overlaps the polarizer 18A1 in the portion 6A of the symbol indicator 5 and the polarizer 1781 in the window overlaps the polarizer 18A2 on the symbol indicator. Since the polarizers 17A1 and 18A] have polarization planes which are parallel to one another, light is permitted to pass therethrough and nothing is seen to exist therein. However, since the polarizers 1781 and 18A2 have polarization planes which are perpendicular to one another. the light incident thereon is intercepted, so that the perfect digit 2 as shown in FIG. 14 can be seenin the window.

In like manner, the polarizers 18A2, 18A3, 18B1 and 18B2 mounted in the portions 613, 6C, 6D and 615 of the symbol indicator 5 cooperate with the polarizers l7Bl, 17A1; 1782 and 17A2 mounted in the slots of the window 4 in indicating other symbols than I and 2 to intercept light and permitting light to pass through the polarizers, so that a visual noise in the form of occurrences of broken portions in the indicated digits can be precluded.

In the illustrated embodiment, the digits are indicated through the window by concealing, by means of the symbol patterns and the polarizers, the portions of the slots of the window 4 which are not required for indicating the respective digits. It is to be understood, however, that the digits can be indicated through the window by revealing the portions of the slots of the window which are required for indicating the respective digits.

As aforementioned, polarizers are mounted in those portions of the overlapping symbol patterns of the symbol indicator which cross one another and in those portions of the slots of the symbol indication window in the mask plate which correspond to the aforesaid intersections of the symbol patterns to eliminate the occurrences of broken portions in the digits indicated in the window. This arrangement is effective to preclude the occurrence ofa visual noise while permitting to indicate symbols in the window in a size twice as large as would otherwise be the case, without increasing the dimensions of the indication device.

The noise can be eliminated by cam means according to this invention. When ancillary members and cam means are used to prevent occurrences of a noise, the

' symbol patterns 6 on the symbol indicator are painted such that

noise producing portions

28A, 28B, 28C, 28D and 28E (FIG. 17) are left unpainted. As shown in FIG. 15, cylindrical cams I9 and constituting cam means-are formed integrally on one end of the symbol indicator 5, such cylindrical cams I9 and 20 being formed on their outer periphery with a plurality of peripheral cam grooves 21. Four

ancillary members

22, 23, 24 and constituting noise prevention means are formed of a resilient material and connected at one end to a part (not shown) such that they normally engage, at

projections

22A, 23A, 24A and 25A provided substantially in the middle, the peripheral surfaces of the cylindrical cams l9 and 20.

The

ancillary members

22 and 25, which are each formed with a hook at the forward end engage the peripheral surface of the clyindrical cam 19 while the

ancillary members

23 and 24, which are not formed with a hook at their forward end, engage the peripheral surface of the cylindrical cam 20. When the

projections

22A, 23A, 24A and 25A drop into peripheral cam grooves 21, the forward ends of the ancillary members move to positions shown at 22a, 23a, 24a and 25a in phantom lines in FIG. 16.

Let us assume that the symbol indicator 5 is angularly intermittently driven so as to successively bring the center lines (a), (b), (c) (g) on the symbol indicator 5 (See FIG. 13) into index with the center of the window 4 in the mask plate 3. The peripheral cam grooves 21 are positioned such that the

projections

22A and 24A drop into the peripheral cam grooves 21 when the center line (a) is indexed with the center line of the window 4, the projection 22A drops into one of the peripheral cam grooves 21 when the center line (b) is indexed with the center of the window 4, the projection 23A when the center line (d) is indexed with the center of the window 4, and the projection 24A when the center line (g) is indexed with the center of the window 4.

The forward ends of the ancillary members 22 to 25 are painted in the same color as the mask plate 3.

7 In operation, when the angular intermittent rotation of the symbol indicator 4 brings the center line (a) shown in FIG. 17 into index with the window 4 in the mask plate 3, the

projections

22A and 24A of the

ancillary members

22 and 24 respectively drop into the peripheral cam grooves 21 and the

ancillary members

22 and 24 move to the positions 22a and 24a shown in FIG. 16 respectively. A comparison of FIG. 16 with FIG. 17 shows that the forward ends of the

ancillary members

22 and 24 have moved to positions designated 28A and 28E respectively in which they cover portions. In this way, the portions of the slots of the window 4 which are not used to indicate the digit 1 are concealed by the forward ends of the

ancillary members

22 and 24, so that the flawless digit 1 shown in FIG. 14 can be indicated in the window 4.

When the center line (b) on the symbol indicator 5 is next brought into index with the center of the window 4, the ancillary member 22 moves so that its forward end 22A is disposed in a portion designated 28B in FIG. 17, so that the portion of the slots of the window which is not used to indicate the digit 2 is concealed by the forward end 22A of the ancillary member 22.

The next angular rotation of the symbol indicator 5 brings the center line (c) into index with the center of the window 4. In this case, no ancillary members move.

In indicating the digits following 3, the forward end portions of the

ancillary members

25 and 24 move to positions designated by 28C and 28D respectively on the symbol indicator and the forward end of the ancillary member 24 moves to a position designated 28E. This permits the flawless digits shown in FIG. 14 to be indicated in the window 4.

FIG. 18 shows a modified form of the windows 4, of the three horizontal slits and two inclined upright slots type, in which the intermediate horizontal slots project htrough and out of the right inclined upright slot. The use of this form of windows 4 permits the digit 4 to be indicated in perfect form shown in FIG. 20.

The rightwardly projecting portion of the intermediate slit is not used except when the digit 4 is indicated,

so that this portion is concealed by portions 6A of the symbol patterns 6 shown in FIG. 19 when digits other than 4 are indicated. The use of the type of window 4 shown in FIG. 18 enables the horizontal memberof the digit 4 to be indicated clearly as projecting rightwardly through the vertical member. This is the natural form ofthe digit 4, so that the digit 4 indicated in the window 4 can be understood correctly. Besides, since the window 4 is inclined toward the right, the use of the symbol patterns 6 arranged in adjacent overlapping relationship does not interfere with the indication of digits in the window.

When the mask plate 3 according to this invention is formed by punching from a metallic plate, the portions of the slots of the window which correspond to the noise producing portions in the symbol patterns on the symbol indicator can be used as connecting portions so as to prevent dislodging of the center shield portions. As shown in FIG. 12, there are four such portions in the window, one portion each in the upper, lower, left and right portions. It will be evident that the use of such portions as connecting portions is advantageous.

What I claim is:

1. A symbol indication device comprising, in combination, a mask plate formed with at least one symbol indication window comprising at least one slit and having a standard line which is inclined with respect to the perpendicular, a symbol indicator carrying thereon at least one series of symbol patterns adapted to cooperate with said symbol indication window to indicate the symbols in succession in said symbol indication window, said series of symbols being inclined with respect to the perpendicular and the symbol pattern in the series being arranged such that half portions of at least some adjacent symbol patterns overlap one another, and drive means for intermittently driving 'said symbol indicator relative to said mask plate through a distance sufficient to bring the symbol patterns successively into indexed relation with the symbol indication window, whereby the symbols can be indicated successively in the symbol indication window in the mask plate; said symbol patterns on said symbol indicator being arranged in a manner such that those symbol patterns which are adjacent each other and which are likely to produce a visual noise when indicated through the symbol indication window do not overlap each other, the symbol patterns being arranged at unequal distances from each other, said drive means driving said symbol indicator relative to said mask plates through unequal distances corresponding to the unequal spacings of said symbol patterns, whereby those symbol patterns likely to produce a visual noise, if overlapped, are brought individually into indexed relation with the symbol indication window.

2. A symbol indication device comprising, in combination, a mask plate formed with at least one symbol indication window comprising three vertically spaced horizontal slots interconnected at their ends by two upright slots parallel to a standard line which is inclined at a preset small angle with respect to the perpendicular, and forming a closed quadrilateral loop divided in half by the intermediate slot of said horizontal slots; a symbol indicator carrying thereon at least one series of symbol patterns each including at least one relatively narrow and elongated rectilinear bar area alignable with at least a portion of at least one of said slots so that said symbol patterns are adapted to cooperate with said symbol indication window to indicate the symbols in succession in said symbol indication window; the symbol patterns of said series being inclined at said preset small angle with respect to the perpendicular, and the symbol patterns in the series being arranged such that less than half portions of at least some adjacent symbol patterns overlap one another; the vertical distance between centers of adjacent symbol patterns being in excess of half the height of each symbol pattern; and drive means operable to intermittently drive said symbol indicator relative to said mask plate through a distance equal to the vertical distance between centers of adjacent symbol patterns and sufficicient to bring the symbol patterns successively into indexed relation with the symbol indication window, whereby the symbols can be indicated successively in the symbol indication window in the mask plate.

3. A symbol indication device as set forth in claim 2 wherein said series of symbol patterns on said symbol indicator have portions which are not used for indicating symbols in the symbol indication window and which are the same color as the surface of said mask plate.

4. A symbol indication device as set forth in claim 2 wherein said series of symbol patterns on said symbol indicator have portions which are used for indicating symbols in the symbol indication window and which are a color different from the color of the surface of said mask plate. 7

5. A symbol indication deviceasset forth in claim 2 wherein said symbol indicator is cylindrical in shape.

6. A symbol indication device as set forth in claim 2 wherein said symbol indicator is in belt form.

7. A symbol indication device as set forth in claim 2 wherein a respective polarizer is mounted at least in one visual noise producing portion of the symbol patterns on said symbol indicator and in the symbol indication window of the mask plate.

8. A symbol indication device as set forth in claim 2 wherein visual noise prevention means is provided between said mask plate and said symbol indicator to conceal noise producing portions whereby production of a visual noise can be precluded as the symbol indicator is intermittently moved.

9. A symbol indication device as set forth in claim 8 wherein said noise prevention means comprises levers adapted to operate in synchronism with said symbol indicator.

10. A symbol indication device as set forth in claim 2 wherein the intermediate horizontal slot projects through the right inclined upright slot and rightwardly thereof.

11. A symbol indication device as set forth in claim 2 wherein said mask plate is formed, at each noise producing portion of said symbol indication window, with a connecting member to support center shield portions. t

Claims

1. A symbol indication device comprising, in combination, a mask plate formed with at least one symbol indication window comprising at least one slit and having a standard line which is inclined with respecT to the perpendicular, a symbol indicator carrying thereon at least one series of symbol patterns adapted to cooperate with said symbol indication window to indicate the symbols in succession in said symbol indication window, said series of symbols being inclined with respect to the perpendicular and the symbol pattern in the series being arranged such that half portions of at least some adjacent symbol patterns overlap one another, and drive means for intermittently driving said symbol indicator relative to said mask plate through a distance sufficient to bring the symbol patterns successively into indexed relation with the symbol indication window, whereby the symbols can be indicated successively in the symbol indication window in the mask plate; said symbol patterns on said symbol indicator being arranged in a manner such that those symbol patterns which are adjacent each other and which are likely to produce a visual noise when indicated through the symbol indication window do not overlap each other, the symbol patterns being arranged at unequal distances from each other, said drive means driving said symbol indicator relative to said mask plates through unequal distances corresponding to the unequal spacings of said symbol patterns, whereby those symbol patterns likely to produce a visual noise, if overlapped, are brought individually into indexed relation with the symbol indication window.

4. A symbol indication device as set forth in claim 2 wherein said series of symbol patterns on said symbol indicator have portions which are used for indicating symbols in the symbol indication window and which are a color different from the color of the surface of said mask plate.

5. A symbol indication device as set forth in claim 2 wherein said symbol indicator is cylindrical in shape.

11. A symbol indication device as set forth in claim 2 wherein said mask plate is formed, at each noise producing portion of said symbol indication window, with a connecting member to support center shield portions.