JPH0124671Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a distance signal generator for a taximeter, and more particularly to a distance signal generator that generates distance pulses necessary for fare calculation only when the vehicle is traveling in the forward direction. It is something.

[Conventional technology]

Conventionally, the rotation of a rotating body that rotates as the taxi vehicle travels is used as a distance signal generator that generates distance pulses according to the travel distance of the taxi vehicle, which is used to calculate fares according to the travel distance of the taxi vehicle. Reflective portions and non-reflective portions are alternately provided on the surface along the rotational direction, light emitted from a light emitting element is incident on the reflective portion and non-reflective portion of the rotating surface, and reflected light from the reflective portion of the incident light is reflected from the reflective portion. Generally used are devices that receive light with a light-receiving element, output an electrical signal corresponding to the received light to the light-receiving element, and generate a distance pulse corresponding to the travel distance of the taxi vehicle based on the electrical signal.

However, in this distance signal generator, the rotating body rotates when the taxi vehicle is traveling in either the forward or backward direction, and generates a distance pulse with each rotation, so the fare on the taximeter is The legal requirement to count only at certain times cannot be met.

Therefore, the applicant of the present application has proposed the following in Japanese Utility Model Application Publication No. 56-33514 as satisfying these requirements:
A distance signal generator as shown in FIG. 6 has been proposed.

The proposed distance signal generator is provided with a rotary body 7 having non-reflective surfaces 5 and reflective surfaces 6 alternately formed on the outer circumferential rotating surface on a rotating shaft 11 that rotates as the vehicle travels,
The light emitted by the light emitting diode 2 driven by the drive circuit 1 to emit light is guided to the outer rotating surface 6 of the rotating body 7 through the optical cable 3, and the light reflected by the reflecting section 6 is guided through the optical cable 3 to the phototransistor 12, where it is phototransmitted. In the device in which the electric signal outputted by the transistor 12 is shaped by a waveform shaping circuit 13 into a distance pulse, a stopper 8 is inserted into a slit 9 in the rotating shaft 11 to restrict rotation beyond a predetermined angle. A cup-shaped light-shielding plate 10 is provided coaxially with the rotating body 7 via a friction transmission mechanism 14, and a movable window 4 is provided on the light-shielding plate 10 at a portion facing the outer circumferential rotating surface of the rotating body,
When the vehicle is moving forward, as shown in FIG. 7A, the movable window 4 is aligned with the end of the optical cable 3 so that light can be introduced to the outer rotating surface and can receive light emitted from the reflective surface 6. When the vehicle is moving backward, as shown in FIG. 7B, the movable window 4 is not aligned with the end of the optical cable 3 to prevent light from entering the outer rotating surface, so that distance pulses can be obtained only when moving forward. I have to.

[Problem that the invention attempts to solve]

In the conventional distance signal generator configured as described above, a light shielding plate 10 is provided on the rotating shaft 11 via a friction transmission mechanism 14 in order to generate a distance pulse only when the vehicle is traveling forward. Although,
In this friction transmission mechanism 14, slip occurs constantly when the rotating shaft 11 rotates, so the friction transmission mechanism 14 wears out due to wear etc., and when the rotation is reversed, the rotation is normally transmitted to the light shielding plate 10. Otherwise, a problem arises in that the light shielding plate 10 does not move from the state shown in FIG. 7A, for example. If such a trouble occurs, a problem arises in that distance pulses are generated even when the vehicle is traveling backwards. That is, in the conventional example described above,
Normal operation of the distance signal generator cannot be guaranteed due to problems with the lifespan of the friction transmission mechanism.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a distance signal generator for a taximeter that generates distance pulses only when the vehicle is moving forward, and thus has a long service life without using mechanical means.

[Means for solving problems]

In order to solve the above problems, the taximeter distance signal generator according to the present invention has a rotation direction that is reversed depending on the direction of travel of the taxi vehicle, as shown in the basic configuration diagram in Fig. 1. reflective parts and non-reflective parts are provided alternately along the rotational direction on a rotating surface of a rotating body that rotates as shown in FIG.
A light receiving element receives reflected light from the reflecting portion of the incident light, outputs an electrical signal corresponding to the received light to the light receiving element, and generates a distance pulse corresponding to the traveling distance of the taxi vehicle using the electrical signal. generate,
In a taximeter that calculates and displays a fare according to the distance traveled based on the distance pulse, the reflective portions 6a, 6b and the non-reflective portions 5a,
5b are provided in two rows, upper and lower, with different phases on the outer circumferential rotating surface of the rotating body 7, and reflective portions 6 are provided corresponding to each row.
Light-receiving elements 12a and 12b are provided to receive reflected light from a and 6b, respectively, and one light-receiving element 12
a change detection means 18a that detects the rise or fall of the electrical signal output by the change detection means 18;
a level determining means 18b for determining the level of the electrical signal output by the other light receiving element 12b upon detection of rising or falling by a; and the level determining means 1;
The present invention is characterized in that it is provided with a pulse generating means 18c which generates a distance pulse when one level is determined by 8b.

[Effect]

In the above configuration, the reflective parts 6a, 6b and the non-reflective parts are arranged alternately in the rotational direction on the outer peripheral rotating surface of the rotating body 7, which rotates so that the rotational direction is reversed depending on the traveling direction as the taxi vehicle travels. 5a,
5b are provided in two rows, upper and lower, with different phases, and the light reflected by the reflecting portions 6a, 6b of each row is transmitted to the light receiving elements 12a, 1.
2b receives the light and obtains two types of pulse train signals, and these two types of pulse train signals are in a relationship such that the level of one pulse train signal at the time of rising or falling changes as the rotation direction of the rotating body 7 changes. Therefore, by determining this by the determining means 18b, the pulse generating means 18c generates a distance pulse only when the vehicle is moving forward.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 2 is a diagram showing an embodiment of the distance signal generator for a taximeter according to the present invention. In the figure, 2 is a light emitting diode, 1 is a drive circuit for driving the light emitting diode 2, and 12a and 12b are photoresists, respectively. Transistors 13a and 13b are pulse waveform shaping circuits that waveform-shape the outputs of the phototransistors 12a and 12b and generate pulse train signals, and 18 is an arithmetic processing unit composed of a CPU that processes the two pulse train signals as input data. Reference numeral 7 denotes a rotating body, and reflective portions and non-reflective portions 5a and 6 are provided alternately along the rotational direction in two rows, upper and lower, divided into two in the direction of the rotational axis 11 on the outer circumferential rotational surface of the rotating body.
a, 5b, and 6b are arranged, respectively. The reflective part and the non-reflective part are shifted by 1/2 in the direction of rotation. 3a and 3b are a plurality of optical fibers that transmit the light from the light emitting diode 2 to the reflective part 5a, the non-reflective part 6a, the reflective part 5b, and the non-reflective part 6b, respectively, and input the reflected light to the phototransistors 12a and 12b. It is an optical cable that bundles together. Further, the rotating body 7 is housed in a case 19 in order to shield the end faces of the optical cables 3a and 3b from external light. The rotation of the rotating body 7 is set to be proportional to the number of rotations of the tires of the vehicle, and is performed via a rotation transmission member (not shown).

In the above configuration, the light generated from the light emitting diode 2 passes through each optical cable 3a, 3b and reaches the rotating body 7. Here, two sets of reflecting parts of the rotating body 7,
The relationship between the non-reflective parts 5a, 6a and 5b, 6b is as follows.
As shown in the figure, each optical cable 3a, 3b is provided with a 1/2 offset along the rotation direction, and when the rotating body 7 rotates in the normal direction, that is, in the direction in which the vehicle moves forward (direction a in the figure), each optical cable 3a, 3b When the tips of the optical fibers 3a and 3b face the reflecting portion 6a, the reflected light enters the optical cables 3a and 3b and is received by the phototransistors 12a and 12b. Here, each phototransistor 12
Assuming that the outputs of the waveform shaping circuits 13a and 13b are high level when reflected light is received by a and 12b, and the outputs are low level when no light is received, the outputs of the waveform shaping circuits 13a and 13b during normal rotation are as follows. It will look like Figure 3B. However, in FIG. 3, 1 is the output of the pulse waveform shaping circuit 13a, and 2 is the output of the pulse waveform shaping circuit 13b.

On the other hand, when the rotary plate 7 is moving in the reverse direction, that is, in the direction when the vehicle is moving backward (direction b in the figure), the outputs of the waveform shaping circuits 13a and 13b are as shown in 1 and 2 in FIG. 3A. Become. That is, they each have a phase difference of 90° with respect to the pulse train during normal rotation.

The pulse train signals of each pulse waveform shaping circuit 13a, 13b obtained during forward rotation and reverse rotation are sent to the CPU.
By inputting the data as data to the arithmetic processing unit 18, the arithmetic processing unit 18 determines whether the vehicle is moving forward or backward and calculates the travel distance.

A flowchart of a program executed by the CPU constituting the arithmetic processing section 18 is shown in FIG.

In Figure 5, the CPU first includes waveform shaping circuit 1.
The rising edge of pulse train signal 1 from pulse train signal 3a is detected (step S40). If a rising edge is detected, it is then detected whether the pulse train signal 2 of the waveform shaping circuit 13b is a high level signal (step S41). If pulse train signal 2 is high level at the rise of pulse train signal 1, forward rotation (forward)
Therefore, the CPU generates the 3 valid pulses shown in FIG. 3B (step S42),
The travel distance is calculated using this effective pulse (step S43).

On the other hand, if the pulse train signal 2 is not at a high level when the pulse train signal 1 rises, the vehicle is in a reverse (reverse) state, so the effective pulse 3 is not generated and no distance calculation is performed.

Note that in the program executed by the CPU, it may be configured to detect whether the pulse signal 2 is at a low level when the pulse train signal 1 rises.

As is clear from the above operation of the CPU, by executing step S40, the arithmetic processing unit 18 functions as the change detection means 18a for detecting the rise or fall of the electric signal output from one of the light receiving elements 12a, and performs step S41. When the change detection means 18a detects a rise or a fall, the level determination means 18b is used as a level determination means 18b for determining the level of the electrical signal output by the other light receiving element 12b.
Each acts as a pulse generating means 18c that generates a distance pulse when it is determined that the distance pulse is at one level.

〔effect〕

As explained above, according to the present invention, reflective parts and non-reflective parts provided on the outer circumferential rotating surface of a rotating body are provided in two rows, upper and lower, with different phases, and the reflected light from each row is converted into an electrical signal to Two types of pulse train signals whose mutual relationship changes depending on the direction of rotation are obtained, and these two types of pulse train signals are electrically processed to generate distance pulses only when the vehicle is moving forward. There is no need to use a light shielding plate that is rotated via a rotation transmission mechanism as in the prior art, and there is no mechanical wear and the service life can be extended.

In particular, since the reflective parts and non-reflective parts are provided in two rows, upper and lower, on the outer circumferential rotating surface of the rotating body that has the largest length in the rotational direction, it is possible to effectively form more reflective parts and non-reflective parts. Moreover, except for the phase shift, the pattern shapes of the reflective and non-reflective parts in the upper and lower two rows can be exactly the same, and the reflective and non-reflective parts can be formed with high accuracy without special efforts. Distance pulses can be generated with high precision.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of a distance signal generator for a taximeter according to the present invention, FIG. 2 is a block diagram showing an embodiment of the distance signal generator for a taximeter according to the present invention, and FIG. B is a timing chart showing pulse train signals obtained from the pulse waveform shaping circuit and CPU in FIG. 1 during forward and reverse rotation; FIG. 4 is a diagram showing reflective parts and non-reflective parts arranged on the rotating body of FIG. 2; Figure 5 is the second
Fig. 6 is a block diagram showing a conventional distance signal generator; Fig. 7 A and B are the states of the rotating body and light shielding plate during forward and reverse rotation in Fig. 6. FIG. 2... Light emitting diode (light emitting element), 5a, 5
b...Non-reflective part, 6a, 6b...Reflective part, 7...
Rotating body, 12a, 12b...Photodiode (light receiving element), 18... Arithmetic processing unit, 18a... Change detection means, 18b... Level determination means, 18c
...Pulse generating means.

Claims (1)

[Scope of Claim for Utility Model Registration] Reflective parts and non-reflective parts are provided alternately along the rotational direction on the rotating surface of a rotating body that rotates in such a way that the rotational direction is reversed depending on the traveling direction of the taxi vehicle. , the light emitted by the light emitting element is incident on the reflective part and the non-reflective part of the rotating surface, the light reflected from the reflective part of the incident light is received by the light receiving element, and an electric signal corresponding to the received light is transmitted to the The taximeter is configured to output a light-receiving element, generate a distance pulse corresponding to the travel distance of the taxi vehicle using the electric signal, and calculate and display a fare according to the travel distance based on the distance pulse. Reflective parts and non-reflective parts are provided in two rows, upper and lower, with different phases on the outer circumferential rotating surface of the rotating body, and a light receiving element is provided corresponding to each row to receive the reflected light from the reflective part, one light receiving element. change detection means for detecting a rise or fall of an electric signal output by the change detection means; level determination means for determining the level of the electric signal output by the other light receiving element when the change detection means detects a rise or fall of the electric signal; A distance signal generator for a taximeter, comprising pulse generating means for generating a distance pulse when one level is determined by the level determining means.