Line recording device

In the disclosed recording device, variable values are measured and recorded on a recorder carrier by moving the record carrier along a given direction. A number of recorders form a row and define separate tracks along the direction when the record carrier moves and trace lines along the tracks when actuated. The recorders are divided into a first group and a second group while suitable means measure the variable values. An energizing arrangement energizes a different recorder of the first group for each one of a number of ranges of measured values and energizes a different recorder of the second group for each one of a number of increments of measured values within each range. Each recorder of each second group is energized for the same corresponding increment regardless of the particular range.

BACKGROUND OF THE INVENTION 
This invention relates to recording devices, particularly the type in which 
several fixed recording members are arranged along a row transverse to the 
transport direction of a record carrier for continuously recording 
variations in values as line diagrams along several tracks. 
In contrast to recording arrangements in which a single writing instrument 
is moved in proportion to the quantity measured, each recording element of 
such recording arrangements traces a line or bar along a recording track 
reserved for a predetermined value range as long as the value detected is 
within this predetermined range. Such step-like recorders should provide 
conspicuous and easily readable indications which are also inexpensively 
machine readable. For this purpose, the values being sensed and recorded 
must be quantizable, and the effects of the discontinuities in the 
indications should be overcome. 
The above requirements are usually obtainable in so-called self-deleting 
recording devices where the rate of change of the quantity measured is 
small compared to the speed of the record carrier. These kinds of 
recording devices stress only variations of measurements just prior to a 
particular event while earlier indications are ignored. This emphasis 
permits the recordings to be stretched out to achieve high resolution over 
a period of time. A typical example is a vehicle-mounted device called an 
accident recorder which particularly maintains a record of the speed of a 
vehicle over the distance most recently travelled. The aforementioned step 
bar graphing is particularly suitable for such a recorder because it 
allows one interpreting the record to attribute indication to specific 
speed ranges. 
The desired recording apparatus with its fixed arrangement of several 
recording members in a row has a decided advantage from the technical 
point of view. It avoids rigid recording means which are moved relative to 
the record carrier, generally in dependence on the sensed values. This 
makes the recording device less sensitive to shocks, reduces its service 
expenses and also simplifies production and mounting. On the other hand, 
the usually restricted recording space available on such a record carrier 
cannot be optimized. This is so because the recording members, which are 
assembled as a recording comb, cannot be arranged as close to each other 
as desired due to space and production limitations. 
Under the circumstances, display resolution of the quantity measured is 
limited, and in many cases unsatisfactory. Often, it is at least important 
to know whether the actual value measured is nearer the lower or upper 
limit of the range indicated. Therefore, proposals have been made to use a 
recording comb which is itself movable transverse to the recording 
direction of the record carrier. However, this has known disadvantages, 
such as the need for expensive mechanical parts and a movable current 
input, and has the effect of generating noise. 
SUMMARY OF THE INVENTION 
An object of the invention is to improve recorders. 
Another object of the invention is to avoid the disadvantages of known 
recording devices with fixed recording members arranged in rows. 
Still another object is to use the recording range of the record carrier 
optimally and essentially to increase the resolution of the representation 
of sensed values while avoiding problems of space and production with 
respect to the arrangement of the recording members. 
According to a feature of the invention, each recording member of a first 
group records inputs representing a given range of sensed values, and the 
recording members of another group trace line diagrams for smaller 
incremental ranges. 
According to another feature of the invention, the recording members form 
parts of a recording comb and a first pulse counter is connected with a 
first group of recording members via a first intermediate store and a 
first decoding circuit while a second counter is connected to a second 
group of recording members via a second intermediate store and decoding 
circuit for controlling the recording members in dependence on the values 
detected. 
These and other features of the invention are pointed out in the claims. 
Other objects and advantages of the invention will be evident from the 
following description when read in light of the accompanying drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
In FIG. 1, a record carrier 1 displays visually recognizable recordings 
produced by magnetic recording or writing members and is driven either in 
dependence upon time or the measured quantity. A recording comb 2 is 
composed of a first low-remanence ferromagnetic sheet metal part 3 forming 
a toothed comb and a second sheet metal part 4 made of the same material 
and operating as a magnetic return. The part 4 forms cutouts 4'. Teeth 5 
of the first sheet metal part 3 project through the cutouts 4' in the 
sheet metal part 4 without touching the latter. The two sheet metal parts 
3 and 4, together with the energizing coils 6 which are mounted on the 
teeth 5 that form the individual recording members, are, according to an 
embodiment of the invention, fastened on a circuit board 7 to be inserted 
into the recording device. 
According to the invention, the recording comb 2 is controlled by having a 
first group 8 of recording members 5 serve to trace stroke or line 
diagrams that signify ranges of sensed values of higher denominations, for 
example, decade denominations. A second group 9 of recording members 5 
which should include a least two recording members 5 are energized so that 
they also trace lines for incremental ranges within each sensed value 
range, simultaneously with the recording of the decade line diagrams. To 
evaluate the recordings therefor, the lower value of the simultaneously 
recorded diagram showing the incremental ranges has to be added to the 
higher value decade lines. 
Still another group 10 of recording members 5, 6 indicate the time and 
operation of the brakes or direction indicators in the vehicle. According 
to an embodiment of the invention, the group 10 is eliminated and only 
groups 8 and 9 are used. 
The formation of the sensed or measured quantity for recording the vehicle 
speed is shown in the block diagram of FIG. 2. Here, a pulse generator 11 
suitably arranged on the vehicle is driven in proportion to the distances 
covered, and therefore, produces a specific number of pulses per distance 
in a transmission line 12. The pulse shape and the pulse intervals may 
vary within wide limits. A low pass filter 13 filters the pulses and 
applies them to a trigger circuit 14 which transmits trigger signals to a 
pulse shaping circuit 15 whose output is received by a frequency 
transformer 16. The frequency transformer 16 is set to produce an output 
each time it receives a predetermined number of pulses corresponding to 
number of pulses per meter and representing the apparatus constant. The 
pulse shaping circuit includes a potentiometer 17 for modifying the pulse 
length to adapt various pulse generators to vehicle data. The pulses 
produced by the frequency transformer 16, which may be said to constitute 
distance pulses, are now introduced into a stepping motor drive 19 that 
controls a stepping motor 18. The latter in connection with suitable 
gearing, if necessary, drives the record carrier 1 as well as a distance 
counter D. A reference or clock pulse generator 20 as well as an AND gate 
21 also receive the output of the transformer 16. The clock pulse 
generator 20 serves to deliver the constant equalizing or measuring 
intervals which are necessary for speed measurements. The generator 20 is 
activated by the leading edge of the first incoming distance pulse Z and 
opens the gate 21 for a measuring time T so that the following distance 
pulses Z may be summed in a binary counter 23. The latter is connected to 
an intermediate store or memory 24 as well as to a decoding circuit 25. It 
is also coupled to a second binary counter 26 for summing the decade 
values of a measured quantity. The counter 26 is connected to a second 
intermediate store 27 which in turn is coupled to a coding circuit 28. 
Upon starting of the clock pulse generator 20, as shown in the pulse 
diagram of FIG. 3, a cancel or reset pulse L resets the counters 23 and 
26. At the end of each measuring time T, a transfer pulse Tr transfers the 
counted values from the counters 23 and 26 to the stores 24 and 27. The 
outputs of the stores 24 and 27 are connected to the decoding circuits 25 
and 28. The decoding circuit 28 energizes the magnetic coils 6 surrounding 
the teeth 5 of group 8 in the recording comb. On the other hand, the 
outputs of decoding circuit 25 energize the magnetic coils 6 about the 
teeth 5 of group 9 on the comb 2. 
The first recording member 5, 6 of group 8 will operate when the measured 
quantity is within its range, of between 10 and 20 km/h or mph. 
Simultaneously, one of the recording members of group 9 may operate. In 
the present embodiment, for each decade speed range, there exist four 
incremental ranges, I representing speed values between 0 and 2.5, 2.5 to 
5, 5 to 7.5, and 7.5 to 10 km/h or mph. These are traced along a separate 
line diagram. 
According to a special embodiment of the invention, the last recording 
member of group 8 is connected directly to the pulse counter 26 through a 
timer circuit 29 which is set when a carry pulse is produced. The time 
constant of the timing circuit 29 is chosen to be shorter than the 
measuring time T so as to cause its recording member to produce a dotted 
recording line and thereby especially identify this speed limit. On the 
other hand, separately energizing this recording member permits extension 
of the measuring range. 
Still another timing circuit 30 responds to the clock pulse generator 20 to 
cause one of the coils 6 and one of the teeth 5 to record time markings. 
FIG. 4 shows a speed diagram of the type produced by the system shown in 
FIGS. 1 and 2. The scale on the right indicates the values represented 
within each range. The diagram is read from left to right starting with 
tracings in the range between 40 and 50 km/h and 2.5 to 5 km/h. Thus, at 
the extreme left, the actual driven speed value may be about 44 km/h. As 
may also be seen from FIG. 4, the vehicle was then accelerated until a 
speed was recorded in the range between 60 and 70 km/h and between 2.5 and 
5 km/h. This represents a speed of approximately 72.5 to 75 km/h. The 
speed was then reduced and the brakes applied as shown by the line 31. 
This resulted in a rapid decrease in the speed. 
The invention retains the merits of recording line diagrams but supplements 
it by incremental values with little expense. It results in an increase in 
the exactness of a recordings of a measured quantity. 
In reading the recordings of FIG. 4, the speed at any time is determined by 
adding the decade value from 10 to 100 km/h to the particular sub decade 
range occurring at that time.