JPS5973889A - Dimmer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to dimming devices in the case of operating electronic devices and illuminating monitoring areas.

Conventionally, the operating and monitoring areas of electronic devices used in dark places have been illuminated using light transmission methods, reflection methods, or scattering methods using transparent acrylic plates, etc., and illuminated types have also been used for operation switches. In either case, there is a knob for dimming.

However, the conventional dimmer knob has a brightness ocln
There are few products that have linearity with respect to Iruma's visual sensory characteristics, which are characterized by brightness. In the process of achieving this, the drawback was that it became extremely expensive.

Furthermore, illuminated knobs and switches have a drawback in that when the light is on, the location and setting state of the switch can be visually recognized, but when the light is off, both the location and the setting state are unclear.

The present invention has been made in view of the above-mentioned conventional circumstances, and
Therefore, an object of the present invention is to solve the above-mentioned drawbacks by using two types of pulse-steep modulation signals, so that the dimming knob has linearity with respect to visual sense, and the operating knob and the To provide a novel optical device which allows the state of a switch to be visually recognized and greatly improves the operability of an electronic device in a dark place.

In order to achieve the above object, the present invention pulse-width modulates the charging voltage of a capacitor using a pre-specified voltage and a sample signal, outputs this as a first illumination signal, and uses this first illumination signal as necessary. pulse width modulation means for generating and outputting a second illumination signal by thinning out the second illumination signal at a certain rate;
and a selection means for selectively outputting the second illumination signal.

Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. When the digital signal 101 outputted by the oscillator 1 is converted into a pulse signal 102 by the pulsing circuit 2,
It is applied to an exponential voltage generation circuit 3 that utilizes capacitor charging. The exponential voltage generation circuit 3 generates an exponential voltage 103 according to the principle described later. - A reference voltage 104 generated by a variable resistor 5 having a resistance value proportional to force and rotation angle is inputted to a voltage comparator 4 together with an exponential voltage 103.

The voltage comparator 4 compares the magnitude of the reference voltage 104 and the exponential voltage 103 and generates a first pulse width modulation signal 105. A portion of the first pulse width modulation signal 105 is applied to the frequency dividing circuit 6 . The frequency dividing circuit 6 generates a second pulse width modulation signal 106 that is thinned out as necessary. The first pulse width modulation signal 105 and the second pulse width modulation signal 106 are applied to the pulse selection circuit 7. A command signal 107 is applied to the pulse selection circuit 7 according to the setting state from an operation knob or switch or the operating state of the electronic device. Accordingly, the first
Either the second pulse modulated signal 105 or the second pulse modulated signal 106 is selected to output the illumination signal 108. Although FIG. 1 shows only the case where the pulse selection circuit 7 has three blocks, these blocks can be arbitrarily set as many as the number of illuminations required.

A specific internal configuration of the pulse selection circuit 7 is shown in FIG.

FIG. 3 shows the relationship between the exponential voltage 103, the reference voltage 104, and the first pulse width modulation signal 105.

Next, a more detailed explanation will be given with reference to FIGS. 1 to 3. First, when a pulse signal (sample signal) 102 is applied to the transistor Q inside the exponential voltage generation circuit 3, the transistor Q ON'' state, the exponential voltage 103 becomes QV and becomes PL state.

At this time, if the period of the pulse signal 1020 is set to Tl, it will take time Tl for the transistor Q to turn ON'' and then turn ON'', so the exponential voltage 103 will change from Pl to P2 to P3 during T1. Change. The rate of change a of the exponential voltage 103 at this time is determined by the charging characteristics of the resistor and capacitor C inside the exponential voltage generating circuit 3.

The reference voltage 104 generated by the variable resistor 5 has a voltage of vl, denoted by b. The voltage of Vj can be freely set between O and ■ by setting the variable resistor 5. However, the voltage at point P3 must be vp3
(The condition of V is satisfied.Here, the intersection point P of a and b
2, the magnitude relationship between a and b is reversed, so the first pulse width modulation signal 10, which is the output voltage of the voltage comparator 4,
5 outputs a digital signal of 0 for the period T2 and 0 for the other periods, with the period T of the pulse signal 102 as the repetition period. This signal is pulse modulated by the reference voltage 104 and the exponential voltage 103 (that is, the pulse signal 102 and the CI-L time constant circuit consisting of the resistor R and the capacitor C). That is, the pulse signal 102 has a pulse width of 1. = Create as a sample signal of [.

1. In the present embodiment shown in Fig. α2, a part of the first pulse width modulation signal (first illumination signal) 105 is inputted to the frequency dividing circuit 6 to reduce the number of slopes and thin out the part where necessary. to generate a second pulse width control signal (second IU Ming IJ) 106, which is constantly outputted as an illumination signal 108 through the pulse shield selection circuit 7, and is output as a command signal 107 as necessary. By applying this to the selection circuit 7, the first pulse width δ 105 is added to the @2 pulse width signal 106 to obtain an illumination signal. This is because in electronic devices used in dark places, it is necessary to always output the second illumination signal 106 to provide weak illumination.
If there is no need for this, it is of course possible to adopt a configuration in which the first or second pulse width modulation signal 105 or 106 is simply switched and selected by the command signal 107 instead of the configuration shown in 2(2). It is.

Therefore, if a variable resistor whose resistance value is proportional to the rotation angle is used to generate a pulse width modulated signal that has an exponential characteristic with respect to the rotation angle, and the illumination means is driven by this pulse width modulation signal, the logarithmic characteristic can be obtained. It is possible to completely correct human visual perception, and by using two types of pulse modulation signals, the settings of operating knobs and switches, as well as the operation of the device, can be controlled in two levels of brightness and darkness in all conditions. Since it can be displayed, it has the effect of realizing a significant improvement in operability that could not be obtained in the past.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing an embodiment of the present invention, Figure 2 is a circuit configuration diagram of the pulse selection circuit shown in Figure 1, and Figure 3 shows the operation of the exponential voltage generation circuit shown in Figure 1. FIG. 3 is a diagram for explaining a process of pulse width modulation using an exponential voltage and a reference voltage. DESCRIPTION OF SYMBOLS 1... Root generator, 2... Pulsing circuit, 3... Exponential voltage generation circuit, 4 @ Medium voltage comparator, 5... Variable resistor, 6... φ frequency dividing circuit, 7 ...Pulse selection circuit, 10
1”...Digital signal, 102...Pulse (g number,
103... Exponential voltage, 104ψ... Reference voltage, 105
...Fist first pulse width modulation signal, 106...Second pulse I width modulation signal, 107...Command signal, 108
・ψ・Lighting signal patent applicant NEC Co., Ltd. Patent attorney Yutabe Kumagai

Claims (1)

[Claims] In an electronic device that has an operating knob, an operating switch, and a display with illumination means and is used in a dark place, the charging voltage of a capacitor is pulse-width modulated using a preset base voltage and a sample signal. Pulse width modulation means outputs the modulated output as a first pulse width modulation signal, and further thins out the first pulse width modulation signal at a necessary rate to generate and output a second pulse @ modulation signal. A light control device characterized by comprising: