U.S. patent number 3,646,544 [Application Number 05/034,788] was granted by the patent office on 1972-02-29 for apparatus for indicating numerical information.
This patent grant is currently assigned to Sanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.. Invention is credited to Hiroshi Yamaguchi.
United States Patent |
3,646,544 |
Yamaguchi |
February 29, 1972 |
APPARATUS FOR INDICATING NUMERICAL INFORMATION
Abstract
A multidigit decimal number display apparatus comprises a
predetermined plurality of numeral display elements corresponding
to a plurality of individual digit display positions each capable
of selectively indicating a minus sign or any desired Arabic
numeral. The apparatus displays the digits of the decimal number on
a time-sharing basis in accordance with data identifying the digits
of the decimal number and registered in a main circulation shift
register. Means are provided for generating a logical state pattern
signal identifying the stages of the main register containing data
identifying the decimal number. Means responsive to the logical
state pattern signal effects cancellation of zeros in all display
positions exceeding the most significant digit of the decimal
number. Further means responsive to the logical state pattern
signal generates an enabling signal identifying the display
position immediately preceding the display position for the most
significant digit of the decimal number. The enabling signal is
also responsive to the state of the decimal number as plus or minus
to activate the immediately preceding display position to display a
minus sign in accordance with that state. Each display element
comprises a plurality of light-emitting segments having a
minus-in-square configuration wherein the horizontal middle segment
is activated to provide the minus sign indication.
Inventors: |
Yamaguchi; Hiroshi (Iwami-gun,
JA) |
Assignee: |
Sanyo Electric Co., Ltd.
(Osaka-fu, JA)
Tottori Sanyo Electric Co., Ltd. (Tottori-shi, Tottori-ken,
JA)
|
Family
ID: |
26373948 |
Appl.
No.: |
05/034,788 |
Filed: |
May 5, 1970 |
Foreign Application Priority Data
|
|
|
|
|
May 6, 1969 [JA] |
|
|
44/730021 |
Sep 12, 1969 [JA] |
|
|
44/350461 |
|
Current U.S.
Class: |
708/166; 377/112;
345/44; 377/40; 708/171 |
Current CPC
Class: |
G09G
3/04 (20130101); G06F 3/1407 (20130101); G09F
9/307 (20130101) |
Current International
Class: |
G09G
3/04 (20060101); G09F 9/307 (20060101); G06F
3/14 (20060101); G08b 005/22 () |
Field of
Search: |
;340/324R,172.5
;235/92RO,92SH,92ST |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Trafton; David L.
Claims
What is claimed is:
1. An apparatus for displaying numerical information
comprising:
a register for registering data identifying a decimal number to be
displayed,
display means for displaying said decimal number, said display
means having a predetermined plurality of display positions for
displaying digits of a decimal number in corresponding
predetermined positions and for displaying a sign indication in
each of a predetermined plurality of positions respectively related
to said digit display positions,
means responsive to said data registered in said register for
controlling said display means to display the decimal number
registered therein,
means for generating an enabling signal identifying a display
position related to the display position for the most significant
digit of the decimal number to be displayed, and
means responsive to the state of said decimal number and to said
enabling signal for controlling said display means to display a
sign indication in a position related to the most significant digit
of the decimal number.
2. An apparatus as recited in claim 1 wherein each of said
plurality of display positions of said display means is operable to
display selectively an individual digit of a decimal number or a
sign indication.
3. An apparatus as recited in claim 2 wherein said means for
generating an enabling signal generates a signal indicative of a
digit position which is one digit position more significant than
the most significant digit position of the decimal number displayed
by said display means.
4. An apparatus as recited in claim 1 wherein:
said display means comprises a plurality of display elements
defining said display positions, and
each of said display elements is operable to display selectively an
individual digit of a decimal number or a sign indication.
5. An apparatus as recited in claim 4 wherein there is further
provided a further display element immediately preceding the most
significant digit display element of said display means, said
further display element being selectively operable for displaying a
sign indication for a decimal number having a most significant
digit displayed in said most significant digit display element.
6. An apparatus as recited in claim 4 wherein each display element
comprises a plurality of selectively activated display segments
arranged in a configuration for indicating any desired digit in
accordance with selective activation of predetermined segments.
7. An apparatus as recited in claim 6 wherein at least one of said
segments may be selectively activated to display a sign
indication.
8. An apparatus as recited in claim 7 wherein said segments are in
the form of minus-in-square and a horizontal middle segment is used
as a minus sign.
9. An apparatus as recited in claim 7 wherein said segments are in
the form of plus-in-square and a horizontal middle segment is used
as a minus sign.
10. An apparatus as recited in claim 9 wherein a horizontal middle
segment and a vertical middle segment are used as a plus sign.
11. An apparatus as recited in claim 1 wherein said register for
data identifying the decimal number to be displayed comprises a
circulation shift register.
12. An apparatus as recited in claim 1 wherein said display means
is operable on a time-sharing basis to sequentially and
repetitiously display each digit and the sign indication of the
decimal number on a time-sharing basis.
13. An apparatus as recited in claim 1 wherein said display means
comprises:
a plurality of display elements selectively operable to display
corresponding individual digits of the decimal number,
a plurality of sign display elements positioned in preceding
relationship with respect to corresponding digit display elements,
and
said means responsive to the state of said decimal number and to
said enabling signal is operable to selectively activate the sign
display element immediately preceding the digit display element
corresponding to the most significant digit of the decimal
number.
14. An apparatus as recited in claim 1 wherein there is further
provided means responsive to said register for inhibiting the
display of a zero digit in each digit position exceeding the most
significant digit of the displayed decimal number.
15. An apparatus as recited in claim 1 further comprising means for
generating a logic state pattern signal identifying digit positions
of said register wherein data identifying the digits of the decimal
number to be displayed is stored.
16. An apparatus as recited in claim 15 wherein there is further
provided means responsive to said logic state pattern signal for
identifying digit positions exceeding the most significant digit
position of the decimal number to be displayed and for cancelling
the display of a zero digit in those digit positions.
17. An apparatus as recited in claim 15 wherein said means for
generating said enabling signal is responsive to said logic means
for generating said logic state pattern signal to identify the
display position for the sign indication of the decimal number.
18. An apparatus as recited in claim 15 wherein there is further
provided means for detecting the state of the decimal number to be
displayed.
19. An apparatus as recited in claim 15 further comprising means
for delaying said logic state pattern signal by one digit position
to identify the sign display position.
20. An apparatus as recited in claim 15 wherein said means for
generating an enabling signal includes:
means responsive to said logic state pattern signal to produce a
further logic state pattern signal of inverted form and delayed by
one display position in time relative thereto, and
means for detecting the state of the decimal number to be
displayed, said logic state pattern signal defining a logic "0" in
all digit positions of the main register wherein data identifying
the digits of the number to be displayed is registered.
21. An apparatus as recited in claim 16 wherein said means for
generating the enabling signal comprises means for logically
combining said logic state pattern signal, wherein that signal
presents the logic "1" for each stage of the main register wherein
data identifying the numerals to be displayed is stored, a signal
comprising said logic state pattern signal in inverted form and
delayed by one display position in time, and a signal identifying
the state of the decimal number to provide a logic sum of these
signals as the enabling signal.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus for displaying numerical
information and, more specifically, to such an apparatus in which a
plus or minus sign indication is provided in such a position as to
be most readily perceived with respect to the digits of its
associated number, as displayed.
2. Description of the Prior Art
It is conventional today to process numerical information in
electronic data processing apparatus; the resultant numerical
information, or output data, produced by the apparatus is then
typically provided to some subsequent utilization device. In
particular, a display device may receive the output numerical
information and convert it for a visual display for observation by
an operator. Such visual display devices may be of various types,
such as indicating tubes, cathode-ray tubes, sheets of paper on
which information is printed by means of a printer, etc.
For the purpose of display of numerical information containing
plurality of digits, a predetermined plurality of indicator, or
display, elements or portions, each operable to display a digit,
are provided in line to form the display system or indicator. In
general, there is provided a number of indicator elements or
portions which exceeds the number of digits in the largest decimal
numbers anticipated to be displayed. Hence, the display of a
decimal number frequently requires less than the total number of
such elements or portions. In those instances, the remaining
elements or portions of more significant position than the digit of
greatest significance in the number displayed are caused to display
a "zero."
Heretofore, a plus or minus sign of the decimal number has usually
been indicated by means of a surplus display element specifically
provided for display of such a sign, and which is positioned
immediately before the most significant digit display element or
portion of the display system.
Display of the sign in such a position, however, makes it difficult
for the operator to observe the sign and relate it to the decimal
number, especially in the case of a decimal number of only a few
digits, relative to the total number of available digit positions.
Such an arrangement for displaying the sign has typically been used
heretofore due to the difficulty presented in providing for a
display of the sign in a position immediately before the most
significant digit of the decimal number since the number of digits
of the decimal numbers varies. The difficulty is especially
aggravated in the case that the decimal number is registered in a
circulation shift register for supply of the information required
for display of the number by the indicator. Thus, it has long been
recognized to be advantageous and desirable to indicate or display
the plus or minus sign immediately before the most significant
digit of a given decimal number, but the prior art has failed to
provide a simplified scheme to do so, irrespective of the number of
digits of the decimal number. The present invention achieves that
purpose.
In effecting such a display of the plus or minus sign, the zeros in
the digit positions exceeding the most significant digit of the
number to be displayed should be blanked out. Many systems have
been proposed heretofore for suppressing or preventing the display
of the undesired zero in the more significant digit positions. A
system for cancelling such zeros is fully disclosed in the Japanese
Pat. application, Ser. No. 44/11309 entitled "Information Output
system," and may be advantageously employed for this purpose, the
inventor of the invention covered by that application being the
inventor of the subject matter of the present application.
Indication, or display, of the plus or minus sign in the
appropriate one of the plurality of possible positions immediately
before the most significant digit of a given decimal number
requires a corresponding plurality of sign display elements for
displaying such sign, each being positioned immediately before
every numeral display element. These indicator elements for display
of the sign, however, may be incorporated into the numeral display
elements.
Many types of numeral display devices have been used as display
elements. One type of them is a device having a plurality of
light-emitting members each having the shape of a given Arabic
numeral, for example, and being selectively controlled so as to
emit light independently. A light-emitting member having the shape
of a plus or a minus sign also is provided in each such device.
Another type of device has a plurality of light-emitting segments
arranged in a generally square configuration and including a
segment or segments forming either a plus sign or a minus sign
interiorly thereof, referenced hereinafter as a plus-in-square or
minus-in-square indicator, or display element. In such a
segment-arranged device, display of an Arabic numeral, for example,
is effected by causing the emission of light in segments selected
in accordance with the numeral to be indicated. In this type of
device, the plus- or minus-shaped segment or segments are
advantageously utilized to provide a plus or a minus sign.
SUMMARY OF THE INVENTION
Briefly stated, the invention comprises a decimal number indicator,
or display means, comprising a plurality of serially arranged
numeral indicator, or display, elements wherein each element is
capable of selectively displaying any desired numeral, and a
plurality of plus or minus sign display elements positioned
immediately before every numeral display element. As hereinafter
appears, each digit or numeral display element may also provide for
display of the plus or minus sign, and thus the display element for
the latter is merely the display element immediately before that
one employed for display of the most significant digit of the
numbers to be displayed. A group of serially arranged numeral
indicator elements display a decimal number in accordance with
information defining that decimal number which has been stored in a
register, typically in a suitable digital code. A means is further
provided for generating an enabling signal representative of the
position of the plus or minus sign indicator element immediately
before the most significant digit of the decimal number to be
displayed. This enabling signal is applied to the indicator so as
to energize the plus or minus sign indicator element which is
immediately before, -- i.e., immediately precedes, the most
significant digit of the displayed number. Thus, a plus or minus
sign is indicated immediately preceding the displayed decimal
number.
The enabling signal is generated by logic means responsive to a
logical state pattern signal which is representative of the digit
positions in the register which store the digital information of
the decimal number to be displayed. As noted, such a plus or minus
signal indicator element may be incorporated into and jointly built
with a numeral indicator element. Thus in a preferred embodiment of
the invention, a plurality of indicator elements each constituting
a digit and being capable of indicating a plus or minus sign as
well as numerals is provided to form an indicator having an
indicating capacity of a desired number of digit positions. By
employing a segment-arranged numeral indicating element or device
having the segments arranged in the form of a minus-in-square, a
horizontal middle segment and/or a vertical middle segment may be
advantageously utilized to indicate a plus or minus sign.
Therefore an object of the invention is to provide an improved
apparatus for displaying multidigit numerical information.
Another object of the invention is to provide such an apparatus for
displaying a plus or minus sign which may be observed with extreme
ease in relation to the displayed multidigit number, regardless of
the number of digits in the number.
A further object of the invention is to provide such an apparatus
wherein a plus or minus sign is displayed immediately preceding a
displayed, multidigit number, regardless of the number of digits of
the decimal number.
Still another object of the invention is to provide such an
apparatus wherein the zeros heretofore provided in the digit
positions exceeding the most significant digit of the displayed
decimal number are cancelled and a plus or minus sign is displayed
immediately preceding the most significant digit of the displayed
number.
It is a further object of the invention to display a plus or minus
sign immediately preceding the multidigit number by driving a plus
or minus sign indicator as a function of an enabling signal
representative of such digit position.
It is still a further object of the invention to provide a
simplified scheme for generating an enabling signal representative
of the digit position immediately preceding the displayed
multidigit numerical information.
It is still a further object of the invention to provide a
simplified indicator for displaying a plus or minus sign
immediately preceding the displayed multidigit numerical
information.
Still a further object of the invention is to display a minus sign
immediately preceding a multidigit decimal number by using a
horizontal middle segment of a segment-arranged numeral indicating
device having the segments arranged in the form of minus-in-square
out of a group of a plurality of such indicating devices forming a
multi-digit decimal number indicator.
These objects and other objects and features of the invention will
be apparent and more fully understood from the following
description of the invention made with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a structure of a segment-arranged numeral display
device for use in an apparatus in accordance with this
invention;
FIG. 2 is a block diagram of an embodiment of the invention;
FIG. 3 is a block diagram of a logic decision circuit included in
the embodiment shown in FIG. 1;
FIG. 4 shows waveforms employed in generating a logical state
pattern signal to which reference is had in explanation of the
operation of the apparatus of the invention; and
FIG. 5 is a block diagram showing the logic circuit between a main
register of FIG. 2 and an auxiliary register of FIG. 3 for
generating the logical state pattern signal.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 is shown a numeral indicating element or device suitable
for employment as one of a plurality of such devices in an
indicator or display apparatus operated in accordance with the
invention. The indicator of FIG. 1 comprises a plurality of
light-emitting segments arranged in a minus-in-square configuration
to which reference was made previously. The apparatus of the
invention may, of course, employ any suitable type of numeral
indicating devices, several alternative forms of which have
previously been mentioned in the description of the prior art.
Thus, the specific device of FIG. 1 is shown only for purposes of
providing a specific example of one form of apparatus constructed
in accordance with the invention.
The numeral indicating device 10 shown in FIG. 1 comprises three
horizontal segments 1a, 1b, and 1c and four vertical segments 1d,
1e, 1f, and 1g. The segments are each of an elongated,
approximately rectangular construction and are arranged in the
noted minus-in-square configuration in FIG. 1. As is apparent with
reference to FIG. 1, the middle horizontal segment 1a may
advantageously and conveniently be utilized, when selectively
illuminated, to provide a minus sign in accordance with the
invention.
A plurality of incandescent lamps 3a through 3g corresponding to
the segments 1a through 1g are positioned directly adjacent to and
centrally of the respectively corresponding segments 1a through 1g.
Energization of the lamps causes uniform, independent illumination
of the corresponding segments and thus by selectively energizing
the lamps, the corresponding, selectively illuminated segments
define a numeral in a relatively continuous configuration for
observation by an operator. The numeral indicating device 10
comprises a single common lead 4 connected to one terminal of the
lamps 3a through 3g and a corresponding plurality of individual
leads 2a through 2g each connected to the other terminal of the
corresponding lamps 3a through 3g.
FIG. 2 shows a block diagram of the numeral display apparatus of
the invention employing the above-mentioned numeral indicating
device 10. It is to be noted that in this embodiment the display is
made on a time-sharing basis. Display systems operating on a
time-sharing basis are well known to those skilled in the art.
Synchronized control in the operation of a system on a time-sharing
basis, such as that of FIG. 2, is well known in the art and thus
specific illustration of the synchronization control circuitry has
been omitted in FIG. 2.
The numeral indicating or display apparatus of FIG. 2 comprises a
pulse distributor 30, a numeral indicating portion 20, a main
register 50 and control circuit means connected therebetween.
Numeral indicating portion 20 comprises a plurality of serially
arranged numeral indicating devices 10a through 10n. The number of
the indicating devices 10a through 10n is selected in accordance
with the maximum desired number of digit or numeral positions to be
displayed by the indicator 20. Each of the numeral indicating
devices 10a through 10n includes a common lead 4 shown extending
vertically upwardly and a group of individual, selectively
energized leads 2a through 2g shown extending vertically downwardly
from each of the individual indicating devices, some of the
intermediate ones of the leads 2a through 2g being represented only
by dotted lines for ease of illustration.
Connected to the respective indicating devices 10a through 10n are
provided a corresponding plurality of transistors 5a through 5n.
Each of these transistors 5a through 5n is connected at its emitter
to the common lead 4 of the corresponding digit indicating device,
at its collector to a common power bus in turn connected to a
positive voltage source terminal 6, and at its base to respectively
corresponding output terminals of a pulse distributor 30. In
accordance with the time-sharing mode of operation of the display
apparatus of the invention, the pulse distributor 30 serves to
distribute pulse signals to the bases of the transistors 5a through
5n to enable them individually and in sequence in a repeating or
cyclical fashion in the sequence of from the least significant
digit to be displayed to the most significant digit and thus in the
sequence of from transistor 5a to transistor 5n, respectively.
The corresponding ones of the individual leads 2a through 2g are
connected in common to the respectively corresponding leads 7a
through 7g. Thus, each of the segments 1a through 1g of all of the
individual indicators 10a through 10n are connected in common to
the respectively corresponding ones of the common leads 7a through
7g. For example, all of the leads 2a are connected in common to the
lead 7a, and the like.
Corresponding to the common leads 7b through 7g there are provided
a plurality of transistors 8b through 8g. A special circuit is
provided for the lead 7a corresponding to the middle horizontal
segment 1a which provides the minus sign in each indicator and will
be discussed hereafter. Each of the transistors 8b through 8g is
connected at its collector to the corresponding one of the common
leads 7b through 7g, at its emitter in common to the collector of
transistor 9 and at its base to the respectively corresponding ones
of the output leads 11b through 11g of decoder 40.
Decoder 40, as described more fully hereafter, decodes the digital
information characterizing a numeral to be displayed and stored in
register 50 for supply to the energizing network for the indicator
elements. In accordance with these functions, decoder 40 includes
the aforementioned output leads 11b through 11g in addition to an
output lead 11a associated with the minus sign indication, and four
input leads 12 connected to corresponding outputs of the least
significant digit storage element 50a of the main register 50.
Main register 50 stores in each of its stages 50a through 50n
digital information identifying the numeral, or digit, which is to
be displayed in the corresponding digit position of the indicating
apparatus 20. Particularly, as herein disclosed, the register 50
stores the digital information in a four-bit binary code supplied
through the input leads 12 from the least significant element 50a
of the register 50 to the decoder 40. The decoder 40 decodes the
digital information thus received and converts it to an output
signal in a new code formation. The new code is represented by the
combined effect of the presence of absence of output signals on the
output leads 11a through 11g. The code signals thus presented on
the leads 11a through 11g cause the corresponding transistors 15
and 8b through 8g to be enabled and thus, in turn, to effect the
energization of the thus selected lamps to cause illumination of
the corresponding segments of the indicator devices 10a through 10n
and thus the display of the desired, corresponding decimal number
in the appropriate numeral indicating devices, all in accord with
the time-sharing operation.
The main register 50, in general, has a capacity of the same number
of digits as the numeral indicating portion 20, each digit storage
element being denoted as 50a, 50b,..., 50n from the least to the
most significant digit. Each digit storage element stores an
information unit, or word, comprising a specific decimal number in
accordance with, for example, a four-bit binary-decimal code.
Numerical information in the main register 50 is circulated in a
direction from the most significant to the least significant bit
and thus in a rightward direction in FIG. 2. The circulation or
shifting is effected in accordance with timing pulses supplied to
the register 50 such that each word registered in each stage of the
register ultimately proceeds to the least significant state 50a
such that the order of presentation is from the least significant
to the most significant digit positions. The digital word, or
number information, arriving at the least significant digit storage
element 5a is fed at a next shift time to the most significant
digit storage element 50n through a connection 501. Such
circulation or shift of the information is made in synchronism with
the distribution of the pulse signals in the pulse distributor 30.
Transistors 5a to 5n are selectively and sequentially enabled to
permit energization of the corresponding display elements 10a to
10n on a time-sharing basis. Accordingly, the transistor of the
group 5a to 5n corresponding to the i-th digit from the least
significant digit of the number to be displayed is enabled just at
the time that the digit word, or number information, in the i-th
digital storage element from the least significant digital storage
element 50a of the number to be displayed and which has been
registered in the main register 50, is introduced or shifted into
the least significant digital storage element 50a.
The transistor 9 is connected at its base to an output lead 13 of a
sign determination circuit 60, the emitter of the transistor 9
being connected to a negative voltage source terminal 14. The
circuit 60 determines the number of digits and the sign, i.e., plus
or minus, of the number registered in the main register 50 and
provides corresponding output control signals on the output leads
13 and 19, respectively. The circuit 60 plays a very important role
in the disclosed embodiment of the invention and will be explained
in more detail subsequently.
Transistor 15, previously noted to be associated with the middle
horizontal segment 1a is connected at its collector to the common
lead 7a, at its emitter to a negative voltage source terminal 16,
and at its base to an output lead 18 from an OR-gate 17. The
OR-gate 17 has two input leads, one being connected to the output
lead 11a of the decoder 40 and the other being connected to another
lead 19 of the decision circuit 60.
The decision circuit 60 is shown and described in more detail with
reference to FIG. 3. The decision circuit 60 comprises an auxiliary
register 70, a plus-or-minus decision circuit 80, an AND-gate 90,
an inverter 100 logic OR-gates 85 and an inhibit gate 81. The shift
register 50 of FIG. 2 is furthermore shown in FIG. 3 in greater
detail than in FIG. 2 to indicate its operative relationship with
the decision circuit 60; it is to be understood, however, that this
is the identical register 50 of FIG. 2. The output from the shift
register 50 furthermore is seen to include four outputs from the
individual bit positions comprising the first three of stage 50n
and the last or least significant bit of the stage 50a.
The structure and function of the decision circuit 60 is considered
in greater detail in conjunction with the discussion hereinafter of
the circuit of FIG. 5 as to which it will be noted identity exists
as to the register 70, the logic OR-gates 85, the inhibit gate 81,
the auxiliary register 70 and their respective interconnections.
The circuit of FIG. 3 is therefore considered here only briefly.
The auxiliary register 70 is a circulation shift register having
the same number of stages as the number of stages in the main
register 50, each stage comprising a bit storage element and
corresponding to the stages of register 50; thus, they are denoted
as 70a, 60b,..., 70n, respectively corresponding to the stages 50a
to 50n and thus from the least to the most significant digit. The
logical state information is derived from the three most
significant bit positions of stage 50n and the least significant
position of 50a of the register 50 through the four input OR-gate
of the network 85 and applied through the two input OR-gate of that
circuit to the most significant stage 70n of the auxiliary register
70. The logical state information stored in every bit storage
element in the auxiliary register 70 is advanced in succession to
the least significant bit storage element 70a in the order of from
the logical state information stored in the least significant bit
storage element 70a to that stored in the most significant bit
storage element 70n. The logical state information arriving at the
least significant bit storage element 70a is fed through a lead
701, inhibit gate 81 and a two input OR gate of the logic circuits
85 to the most significant bit storage element 70n for the purpose
of recirculating the logical state information in the auxiliary
register 70.
The information registered in the auxiliary register 70 comprises a
logical state pattern that is representative of the discrimination
of the digit positions in the main register 50 wherein there is
stored the data, or numerical information, of the number to be
displayed. Assume, for example, that a number registered in the
main register 50 includes two digits, and at a given moment the
data for the said number is stored in the two stages of the
register 50 comprising the least significant digit storage element
50a and the next significant digit storage 50b. At that time, the
information registered in the auxiliary register 70 is a logic
state pattern comprising the logic designation "1," or one, in the
least significant bit storage element 70a and also in the next
successive significant bit storage element 70b, and with the logic
designation "0," or zero, in the remaining, successively more
significant bit storage elements, as shown as A in FIG. 4. As seen
from the illustration, the information registered in the auxiliary
register 70 is representative of the digit positions, or stages of
the main register 50, in which the data representing the number to
be displayed is stored. An output signal is obtained on output lead
13 of the decision circuit 60 only when a logic "1" is presented in
the least significant bit position 70aof the register 70.
As previously noted, each of the registers 50 and 70 circulates, or
shifts, the information contained in the stages thereof from the
most significant to the least significant position such that all of
the stored data in the register 50 is presented in succession at
the least significant stage 50a. Correspondingly, a logic "1"
condition is presented in the least significant bit storage element
70a of the auxiliary register 70 only when there is also presented
data identifying a numeral to be displayed, at that same time
period, in the least significant stage 50a of register 50. With
reference to FIG. 2, therefore, transistor 9 is enabled by the
output signal on lead 13 from the decision circuit 60 and in turn
enables transistors 8b through 8g only during those times in which
data is presented to the decoder 40 identifying a numeral to be
displayed.
Assume that a decimal number to be displayed contains m digits and
that the main register 50 has a capacity of n digits. Where m<n,
in prior art display apparatus the numeral zero would be displayed
by the numeral display devices of the display system 20 which
correspond to the n-m more significant digits which, in relation to
the main register 50, corresponding to the n-m more significant
data storage stages. In the embodiment as shown in the FIG. 2,
however, such zeros in the said n-m more significant digit position
are inhibited from being indicated as a function of the logic state
pattern signal A in the auxiliary register 70. The logic state
pattern signal A shown and discussed above with reference to FIG. 4
may be produced in accordance with the system comprising the
subject matter of Japanese Pat. application, Ser. No. 44/11309
entitled "Information Output System". The system of that other
application is described herein in sufficient detail to understand
its operation in the context of the display system of this present
invention.
In FIG. 5, there is shown in block diagram form the system of the
above-noted application. The system includes a main register 50 and
an auxiliary register 70, such as shown and discussed in relation
to FIGS. 2 and 3, respectively, and logic means which interconnect
the registers 50 and 70. Each of the stages 50a through 50n is
indicated by dotted lines to contain the storage of four bits
identifying a single digit or numeral to be displayed in accordance
with the bit data stored therein. The logic means comprises a first
logic means 85 responsive to the presence of, or storage of, a
digit in any of the stages of the main register in accordance with
the storage therein of a digit of the stored decimal number other
than zero by detecting a preselected set of four consecutive bit
positions. The logic means 85 also serves to write the resultant
information from the detection into a bit position in the auxiliary
shift register 70, thereby to designate in the latter the positions
of digits in the corresponding positions or stages, of the main
register 50. A second logic means 81 is connected between the stage
70b, the next to the least significant stage 70a, and the most
significant stage, particularly the stage 70n, for circulating the
information stored in the stages of the auxiliary shift register 70
in synchronism with the circulating of the information stored in
the stages of the main shift register 50 and for rewriting, or
shifting and storing, the information thus stored into the adjacent
bit positions of the auxiliary register 70. The rewriting, or
restoring, of the information, however, is inhibited by the second
logic means 81 with respect to and thus as a function of the stored
information corresponding to the least significant digit of the
decimal number registered in the stages of the main shift register
50. During the repetition of the circulation, a bit pattern signal
or logic pattern signal A as shown in FIG. 4 is effectively
generated by the auxiliary register 70. The logic "1" states in the
logic state pattern are indicative of the digit positions of the
digital number to be displayed, as registered in the main register
50. The bit pattern or logical state pattern signal thus developed
is applied to the display system 20 through a control circuit 95 so
as to prevent the undesired "0" display from being effected in the
digit positions of the display exceeding the position of the most
significant digit of the numeral to be displayed.
Referring again to FIG. 3, the plus-or-minus decision circuit 80,
the AND-gate 90, and inverter 100 cooperate with the auxiliary
register 70 to generate an enabling pulse on the output lead 19 to
effect the display of a minus sign in the display position next
adjacent to the most significant digit position, the plus or minus
decision circuit 80 operating to determine the plus or minus state
of the number to be indicated and to supply to the AND-gate 90 a
control signal indicating the state of the decimal number as being
minus, i.e., a minus signal. The AND-gate 90 includes as inputs the
output lead from decision circuit 80 comprising the noted minus
signal and two input leads 702 and 703, the lead 702 being supplied
through the inverter 100 from the output of the least significant
digit storage element or stage 70a while the lead 703 is connected
to the most significant digit storage element 70n of the auxiliary
register 70.
The signal thus provided on lead 702 is the converse of the logic
state pattern signal A, i.e., NOT A or A, and is shown at B in FIG.
4. The signal presented on the lead 703 from state 70n is a signal
delayed by one digit time with respect to the signal A and is shown
at C in FIG. 4. The AND-gate 90 therefore responds to the presence
of a minus indication signal or output from the plus-or-minus
decision circuit 80 and the signal B comprising the NOT of the
signal A, i.e., A, and the delayed signal C to produce an output
comprising the signal of waveform D in FIG. 4; the waveform D will
be recognized to provide a logic "1" or true output of a one digit
time duration and one digit time position in advance of the most
significant digit position of the number to be indicated.
Thus, again with reference to FIG. 3, and also in relation to FIG.
2, there is provided on the output lead 19 of the circuit 60 the
signal D which, applied through gate 17 and lead 18 to the base of
transistor 15, provides for enabling the transistor 15 when, and
only when, the decimal number to be displayed, and which is
registered in the main register 50, is a minus state number and
when, and only when, the stored information of the most significant
digit of the decimal number to be displayed, has arrived at or been
shifted to the most significant digit position or storage 50n of
the main register 50. The enabling of the transistor 15 as thus
effected serves to energize the common lead 7a and the
corresponding leads 2a, and through the remaining logic circuitry,
effects the display of a minus sign by the indicating element which
immediately precedes the indicating element then effecting the
display of the most significant digit of the decimal number then
being displayed by the numeral display system 20.
The system disclosed may, of course, accommodate the particular
situation wherein of a given decimal number to be indicated, the
digits thereof may potentially occupy or correspond to all of the
digit positions which can be accommodated by the numeral display
system 20. In view thereof, it is preferred to provide a display
device capable of displaying only a minus sign and positioned
immediately preceding the most significant digit position of the
numeral display system 20. Such a display device may be of far
simpler construction, of course, or may be identical to the other
display elements. The signal required for energizing this minus
sign display device, such as a signal for energizing a lamp to
provide that minus display, may readily be generated by the output
of an AND gate which comprises the logical product of the following
three signals; a timing pulse occurring at a time when the stored
digital information of the most significant digit or numeral of the
digital number to be displayed, in this instance, is shifted to or
arrives at the least significant digit storage element 50a of the
main register 50; the signal A; and the presence of an output from
the plus-or-minus decision circuit 80. It is noted that under these
circumstances, the logic state pattern A indicates a logic "1" in
all bit positions or stages; thus, no output is presented in output
lead 19 for energizing the noted minus sign display segments of the
numeral display devices.
As a specific example of the operation of the system of the
invention, there is discussed hereafter the display of the digital
number "-20. " In accordance with the foregoing description of
operation of the system, the digital information identifying the
number 20 has been registered in the main register 50 and is
shifted or circulated through the stages of the main register 50 as
a function of the timing pulses. Simultaneously with and during the
time that the digital information identifying the least significant
digit of the number to be displayed, i.e., the logical state
pattern information of "0," is stored in the least significant
digit storage element or position 50a, the transistors 5a and 8b
through 8e, inclusive, and transistor 9 are enabled or turned on.
There results the illumination of the segments 1b through 1g,
inclusive, in the numeral display device 10a, thereby displaying
the numeral "0" for observation by an operator.
Following that time interval, the above-noted shifting occurs such
that during the next digit time, data identifying the logical state
information of the digit "2" is shifted into and stored in the
least significant digit storage element 50a. The digit "2" in the
example is both the successively next significant digit and also
the most significant digit of the decimal number to be displayed.
In this digit time, therefore, the transistor 5b is enabled by the
register 50 and the transistors 8b, 8c, 8e, and 8f, and the
transistors 9 and 15 are enabled, resulting in illumination of the
segments 1b, 1c, 1e, 1f, and 1a in the numeral display device 10b.
The numeral "2" is thereby displayed by the device 10b for
observation by the operator.
In the subsequent or next successive time period following that
during which the numeral "2" was displayed as above described and
thus during the digit time period in which the logical state
information of the numeral "2" is stored in the most significant
digit storage element 50n, the transistor 5c is enabled by the
appropriate output of pulse distributor 30 and the transistor 15 is
enabled as a function of the signal D described hereinabove in
relation to FIG. 4. There results the illumination of the middle
horizontal segment 1a in the device 10c effecting the display of a
minus sign for observation by the operator.
The speed or repetition rate at which the display elements are
selectively energized in accordance with this time-sharing basis of
operation, is, of course, selected to assure visual persistence for
ease of observation by the operator.
In case a number to be indicated is a plus number, no sign is
indicated in the embodiment as disclosed in the foregoing
description. Thus it is seen that no such sign immediately before
the indicated number means the number is plus.
Though a light-emitting segment-arranged type numeral indicating
device has been employed in the embodiment as disclosed herein, it
is obvious to those skilled in the art that a common numeral
indicating device such as a Nixie tube, which has an electrode for
indicating a minus sign may also be utilized in the system in
accordance with the invention. In this connection, it is to be
pointed out that by employing, for example, a segment-arranged
numeral indicating device having the segments arranged in the form
of a plus-in-square and by employing a suitable additional circuit
it is possible to indicate a plus sign as well as a minus sign
immediately before the most significant digit of the indicated
decimal number. Though in such a preferred embodiment as disclosed
herein the numeral indicating device is capable of indicating a
minus (or plus and minus) sign as well as the numerals, this should
not be construed by way of limitation. Further, it will be
appreciated that a plurality of separate indicating devices for
displaying only a minus sign or either or both plus and minus
signs, may be provided in positions immediately preceding and
corresponding to every numeral display device and may be
selectively activated in accordance with the system of the
invention.
Accordingly, the term "state" is used hereinafter to signify the
positive or negative state of the decimal number to be displayed
and the term "sign" is employed to designate either or both of the
positive and negative sign indications. As noted, the display of
the sign for the purposes of the invention is sufficient if it be
only minus, since in the absence of a sign display the number is
understood to be positive, and the opposite likewise is true. In
some applications, however, display of both positive and negative
signs may be desired and the system of the invention clearly
contemplates any of these specific display techniques for
indicating the sign.
The embodiment as disclosed herein also employs the auxiliary
register 70 for the purpose of generating the signal A and delaying
by one digit time the signal A to obtain the signal C. However,
this should not be construed by way of limitation. Alternatively, a
delay device having a capacity of one digit time delay may also be
utilized.
According to the invention, a minus sign is indicated immediately
before the most significant digit of a given number, assuming that
it is a minus number, irrespective of the number of digits of the
said number to be indicated. Therefore, discrimination of the
number to be indicated being plus or minus is readily perceived by
the operator of the machine having the numeral indicating or
display apparatus in accordance with the invention. Another
advantage is that the invention is applicable to conventional
numeral display devices operating on a time-sharing basis without
any extensive modification.
While specific preferred embodiments of the invention have been
described it will be apparent that obvious variations and
modifications of the invention will occur to those of ordinary
skill in the art from a consideration of the foregoing description.
It is therefore desired that the present invention be limited only
by the appended claims.
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