JPS6136885Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an indication value detection device that detects an indication value by a pointer using light. For example, in a conventional device for detecting the indicated value using the pointer of a meter, etc., a disk with a hole is provided on the pointer shaft, and when the pointer rotates, the pointer is placed opposite to It was detected optically by a combination of a lamp and a light sensor.

Therefore, the disk is integrally provided on the pointer shaft, which increases the inertial weight of the pointer shaft, and the conventional meters have the disadvantage of poor indication response.

This invention was made to eliminate the above-mentioned drawbacks, and uses the lamp light of the pointer illumination lamp that leaks from the tip of the pointer to ensure accurate reading of the value indicated by the pointer without reducing responsiveness. It is an object of the present invention to provide an indication value detection device that detects signals well.

An embodiment of the present invention will be described in detail below with reference to FIG. In this embodiment, the present invention is applied to a so-called pointer-emitting meter in which the pointer is illuminated so that it emits light. In Figure 1, 1
is an oscillator which outputs a single-period rectangular wave pulse, which lights up the pointer illumination lamp 2, and further supplies the rectangular wave pulse to a differentiating circuit 8, which will be described later. Furthermore, the oscillation frequency and duty of the oscillator 1 may be the same oscillation frequency but the duty may be different, so the value is such that the lamp 2 appears to be lit at a constant brightness due to the visual afterimage effect. Furthermore, the cycle is different from that of the commercial power supply.

Furthermore, as shown in FIG. 2, the frequency and duty are set so that at least most of the frequency components that make up the rising and falling edges of the frequency components that make up the rectangular wave pulse pass through the high-pass filter 6, which will be described later. has been done. In addition,
Duty is the time ratio of repeating light and dark. 3 is a pointer formed of conductor light, and this pointer is attached to the pointer shaft 3'
It is constructed so that the lamp light from the lamp 2 can enter therein while being supported by the lamp 2, and is illuminated so as to emit bright light as the incident lamp light is repeatedly reflected inside the lamp. Further, the pointer is configured so that a portion of the lamp light incident on the inside of the pointer leaks from the tip. 4 is a scale plate, and 5 is an optical sensor provided at a position corresponding to a scale that needs to be read on the scale plate, and the optical sensor is configured to receive lamp light leaking from the tip of the pointer 3. When the pointer 3 is in a predetermined position, it is fixed on the extension line toward the center of rotation of the pointer 3. Note that since the optical sensor is provided on the display surface side of the scale plate 4, it is not affected by light from outside other than the lamp light, such as natural light of constant brightness, or by the shade of a three-dimensional object such as a bridge railing. It also receives natural light with repeated brightness and darkness and converts it into electrical signals. Reference numeral 6 denotes a high-pass filter, which is one of the differentiating circuits, and the cutoff frequency of the high-pass filter is ₀ , which is generated by the electric signal from the optical sensor 5 due to the repeated brightness and darkness of natural light caused by driving near a shade such as a handrail. It is set higher than the low frequency that makes up the gradual change part, and lower than most of the frequency components that make up the electrical signal from the optical sensor 5 caused by the lamp light that is repeatedly turned on with a single frequency square wave pulse. There is. Therefore, at least the frequency components constituting the rising and falling portions of the electric signal from the lamp light are amplified by the high-pass filter 6 and output, but the electric signal due to the gradual repetition of brightness and darkness of natural light due to external factors is It is blocked by the high pass filter 6. Note that when there is external light such as natural light that repeatedly changes sharply between bright and dark, or external artificial light such as street lights, electrical signals due to these external lights are output from the optical sensor 5, and the electrical signals are output from the optical sensor 5. Among the frequency components constituting the signal, the frequency components higher than the cutoff frequency ₀ of the high-pass filter 6 are amplified and output from the high-pass filter 6. Reference numeral 7 denotes a waveform shaping circuit, which is supplied with a damped oscillating waveform of steep rising and falling parts that has passed through the high-pass filter 6, and is rectified, integrated, and waveform-shaped, and has a waveform of 1 for each of the rising and falling parts. Each pulse generates a square wave pulse. Reference numeral 8 denotes a differential circuit using a digital circuit, which generates one rectangular wave pulse having a pulse width smaller than the pulse width of the rectangular wave pulse supplied from the oscillator 1, one each at the rising edge and the falling edge of the rectangular wave pulse. ing. Reference numeral 9 denotes an AND gate, which outputs a high level when a rectangular wave pulse is supplied from the waveform shaping circuit 7 while a rectangular wave pulse is supplied from the differentiating circuit 8. Reference numeral 10 denotes a counter having a reset terminal R. After being reset by a reset signal from an OR gate 12, which will be described later, it starts counting the number of output pulses from the AND gate 9, and when the counted value reaches a predetermined value, it starts counting. The output signal is supplied to a latch circuit 13, which will be described later. However, if the count value is reset before it reaches the predetermined value, the count result is returned to zero and counting starts again. Reference numeral 11 denotes a timer having a reset terminal R, which is activated when the first output pulse from the AND gate 9 is supplied after being reset by a reset signal from an OR gate 12', which will be described later. At the end of the timer period, a reset signal is supplied to OR gates 12 and 12', which will be described later. Note that the timer time of the timer 13 is set to be slightly larger than a multiple of the period of the rectangular wave pulse output from the oscillator 1. For example, the timer time is set by the oscillator 1 above.
If the pulse width is made slightly larger than the pulse width of the rectangular wave pulse output from the AND gate 10, the number of pulses from the AND gate 10 counted by the counter 10 within this timer time will be 2 pulses. Therefore, since the pulse signal based on natural light with repeated brightness and darkness has a period sufficiently longer than the period of the rectangular wave pulse outputted from the oscillator 1, when the pulse signal is supplied via the AND gate 9, , the timer time ends before the count value reaches a predetermined value, and the timer 11 starts OR gate 1, which will be described later.
A reset signal is supplied to the reset terminal R via the counter 2, and the counter 10 is reset. However, when a rectangular wave pulse based on the lamp light from the lamp 2 is supplied via the AND gate 9, the counter 12 completes counting a predetermined number of times within the timer time and determines that the rectangular wave pulse is due to the lamp light. outputs a pulse signal indicating that the Reference numerals 12 and 12' designate OR gates which input respective reset signals supplied from the timer 11 and the electronic speech synthesizer 14, which will be described later, to the counter 10, respectively.
and supplying it to the reset terminal R of the timer 11,
It is being reset. Reference numeral 13 denotes a latch circuit, which has a reset terminal R, and is connected to an electronic speech synthesizer 14, which will be described later.
The output of the counter 10 is latched to a high level by the first pulse signal from the counter 10 after being reset by the reset signal supplied from the electronic voice synthesizer 14. This latched state will not be released until supplied. Reference numeral 14 denotes an electronic voice synthesizer, which is activated by the output signal latched to a high level from the latch circuit 13, and emits voice from a built-in speaker. Preferably, the electronic speech synthesizer 14 has a plurality of input terminals to which signals from other meters and sensors provided in other parts are supplied together with the signal from the latch circuit 13, and each input terminal The input signals supplied to the device are sequentially processed according to a predetermined priority order, and then a predetermined sound is generated from the speaker once or several times in succession. Thereafter, after a certain period of time, the electronic speech synthesizer 14 issues a reset signal using a built-in timer, and the OR gates 12, 12' and the latch circuit 1
3.

Next, the operation of the above configuration will be explained. When the tip of the pointer 3, which rotates as the speed of the vehicle increases or decreases, reaches a position facing the optical sensor 5, the optical sensor 5 detects the external light that it has been receiving, such as natural light with a constant brightness, In addition to natural light that alternates between bright and dark, or artificial light from street lights, etc., it also receives lamp light leaking from the tip of the pointer 3, and outputs an electrical signal corresponding to the combined amount of light. Among the output signals from the optical sensor 5,
The frequency components constituting the waveform of the gradual change part of the electrical signal caused by natural light with constant brightness and the electrical signal caused by natural light that repeats brightness and darkness are blocked by the high-pass filter 6 and are not passed through. An electric signal caused by the lamp light and a frequency component of a frequency higher than the cutoff frequency ₀ , which constitutes a waveform of a sudden change part of the electric signal caused by natural light with repeated brightness and darkness, are output. The output signal of this high-pass filter 6 is transmitted to a waveform shaping circuit 7.
The signal is supplied to the AND gate 9 via. The oscillator 1 also supplies a rectangular wave pulse to a differentiating circuit 8 composed of a digital circuit, generates one rectangular wave pulse at each of the rising and falling portions of this rectangular wave pulse, and supplies them to an AND gate 9. ing. The AND gate 9 emits an output pulse only when a rectangular wave pulse is supplied from the differentiating circuit 8 and when a rectangular wave pulse is supplied from the waveform shaping circuit 7. The output pulse output from the AND gate 9 is supplied to the counter 10 and timer 11, and when the counter 10 and timer 11 are in the reset state, both start operating at the same time. The counter 10 counts the output pulses from the AND gate 9 within the timer time of the timer 11, outputs a pulse signal only when a predetermined number of pulses have been counted, and latches the reset output of the latch circuit 13 to a high level state. The electronic speech synthesizer 14 is operated to generate sound from the built-in speaker, and after a delay time set by the built-in timer, a reset signal is supplied to the latch circuit 13 to reset it. This reset signal is also supplied to the timer 10 and counter 11 via the OR gates 12 and 12' to reset them and return them to their initial states.

As described above, the present invention includes an oscillator 1 that lights and drives a pointer illumination lamp 2 with a rectangular wave pulse that differs in at least one of the light-dark cycle or the light-dark time ratio of external light, and the pointer 3 in a predetermined position. an optical sensor 5 that receives the light from the lamp 2 guided by the pointer when the pointer moves, on the front side of the scale plate 4; and a high-pass filter 6 that blocks low frequency components of the electrical signal caused by the light incident on the optical sensor. a waveform shaping circuit 7 that shapes the electric signal from the high-pass filter into a rectangular wave pulse; and a differentiation circuit 8 that outputs one rectangular wave pulse at each rise and fall of the rectangular wave pulse from the oscillator 1. , an AND gate 9 that outputs a rectangular wave pulse from the waveform shaping circuit 7 when a rectangular wave pulse from the differentiating circuit is supplied, a counter 10 that counts output pulses from the AND gate, and a counter 10 that counts output pulses from the AND gate. A timer 1 that sets a time corresponding to the pulse width of the rectangular wave pulse from the oscillator 1, even if the counting time is short.
The present invention provides an indication value detection device characterized by having the following features, and by using an electronic speech synthesis device using a microcomputer, it is possible to provide a compact and sound generating instrument with excellent vibration resistance. can. In addition, according to the present invention, lamp light leaking from the tip of the pointer and natural light can be separated by pulse width using an AND gate without putting unnecessary load on the pointer shaft, making it resistant to noise. We were able to demonstrate the effectiveness of detection without reducing responsiveness.

[Brief explanation of the drawing]

Fig. 1 is a block diagram including a vertical cross-sectional view showing the configuration of a sound generating instrument according to an embodiment of the present invention;
The figure is a graph showing the relationship between the distribution of frequency components of lamp light and external light and the cutoff frequency of a high-pass filter. 1... Oscillator, 2... Lamp, 3... Pointer,
3'... Pointer axis, 4... Scale plate, 5... Optical sensor, 6... High pass filter, 7... Waveform shaping circuit, 8... Differential circuit, 9... AND gate, 10
...Counter, 11...Timer, 12, 12'...
...OR gate, 13...Latch circuit, 14...Electronic speech synthesizer.

Claims (1)

[Scope of utility model registration request] An oscillator 1 that drives a pointer illumination lamp 2 to turn on with a rectangular wave pulse that differs in at least one of the light-dark period or the light-dark time ratio of external light; an optical sensor 5 that receives the light from the lamp 2 guided by the lamp 2 on the display surface side of the scale plate 4; a high-pass filter 6 that blocks low frequency components of the electrical signal caused by the light incident on the optical sensor; a waveform shaping circuit 7 that shapes the electrical signal into a rectangular wave pulse;
A differentiating circuit 8 outputs one rectangular wave pulse at each rise and fall of the rectangular wave pulse from the oscillator 1, and when the rectangular wave pulse from the differentiating circuit is supplied, the waveform shaping circuit 7 outputs one rectangular wave pulse. an AND gate 9 that outputs a rectangular wave pulse, a counter 10 that counts output pulses from the AND gate, and a counting time of the counter that is at least a time corresponding to the pulse width of the rectangular wave pulse from the oscillator 1. An instruction value detection device characterized by comprising a timer 11 for setting.