JPH10321381A - Output pulse control device and dimming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an output pulse control device capable of precisely controlling a duty ratio of an output pulse. SOLUTION: In a processing process for reducing a duty ratio, when on time in the next period in an output pulse comes (YES in S1), if the set duty ratio is not 50% or more (NO in S2), the setting time of on time t1 in the next period is switched from the standing up period of time of the output pulse to the standing down period of time. In a process decreasing the duty ratio in order independent of the processing capacity of a device, even after the setting on time is made shorter than the time requiring in processing for changing the on time, short on time can be set, the duty ratio of the output pulse can smoothly be changed until it becomes 0%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output pulse control device suitable for a dimmer.

[0002]

2. Description of the Related Art Conventionally, in a case where a room lamp is gradually dimmed after a door is fully closed in an automobile, for example, a waveform of a voltage supplied to the room lamp is pulsed, and a pulse voltage of the pulse voltage is supplied to the room lamp. A pulse width modulation method for controlling brightness by gradually decreasing or increasing the duty ratio has been used.

That is, as shown in FIG. 5, the on-time t1 in one cycle T of the pulse voltage is gradually reduced stepwise at regular intervals determined in accordance with the sensitivity of the human eye to a change in light and shade ( Or increase) and gradually change the room lamp accordingly (see FIG. 6). When turning off the light, generally, the on-time t1 is controlled to zero immediately before the room lamp is completely turned off. Further, the change of the on-time t1 within one cycle T is specifically changed at the rising point A of the output pulse.

[0004]

However, when the brightness of a room lamp is to be smoothly changed by the above-described conventional pulse width modulation method, if the processing capability of a device for generating an output pulse is low, the following problem occurs. Will occur.

That is, when the room lamp is turned off, immediately before the room lamp is turned off, the above-mentioned 1 is set.
The on-time t1 in the cycle T becomes extremely short, but if this becomes shorter than the time t2 required for the process of changing the length of the on-time t1, as shown in FIG. 7, the length of the next on-time t1 is changed. In some cases, the ON state may be continued during the cycle. Therefore, in that case, as shown in FIG. 8, the brightness of the room lamp flickers for a moment immediately before turning off.

That is, depending on the processing capability of the device that generates the output pulse, it may not be possible to finely adjust the brightness immediately before the light is turned off.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and has an output pulse control device capable of precisely controlling a duty ratio of an output pulse, and a dimming device capable of finely adjusting brightness. It is intended to provide a device.

[0008]

According to a first aspect of the present invention, there is provided an output pulse control apparatus for controlling a duty ratio of an output pulse, in accordance with a change in an ON time within one cycle. The length of the on-time to be changed is compared with the length of the preset switching time, and when the former is longer, the change-over time of the on-time is set to the rising point of the output pulse, while the latter is longer. If it is long,
Control means is provided for setting the on-time change timing at the time of the falling edge of the output pulse.

In such a configuration, when changing the on-time within one cycle, if the on-time to be changed is longer than the switching time, the on-time is changed at the rising edge of the output pulse, and conversely, the on-time to be changed is changed. When the switching time is shorter than the switching time, the ON time is changed at the time when the output pulse falls. Therefore, as the switching time,
By setting the time required for the on-time changing process to be changed, the correct time is always set without delay in the changing process even in an apparatus whose on-time changing process is slow.

[0010] Further, in the invention of claim 2, the length of the switching time is a length for setting the duty ratio to 50%. In such a configuration, the time required for the above-described on-time change processing, that is, the length of the switching time is uniquely set based on the duty ratio regardless of the processing capability of the device, so that setting of the switching time for each device is unnecessary. Become.

According to a third aspect of the present invention, in the output pulse control device for controlling the duty ratio of the output pulse, the ON time in one cycle is sequentially changed, and the length of the ON time to be changed is set in advance. With the set switching time length, when the on-time is reduced, the setting time of the on-time length is switched from the rising point of the output pulse to the falling point, while the on-time is increased. And a control means for switching the setting time of the length of the on-time from the falling point of the output pulse to the rising point.

In such a configuration, when the on-time in one cycle is sequentially reduced, the length of the on-time is initially set at the time of rising, and the length of the on-time becomes the length of the switching time. , The length of the ON time is set at the time of falling. Conversely, when sequentially increasing the on-time within one cycle, the on-time length is initially set at the falling point, and the on-time length becomes the switching time length. Is set at the time of rising.

For this reason, by setting the time required for the process of changing the ON time to be changed as the switching time, even in a device in which the process of changing the ON time is slow,
The on-time can be smoothly increased or decreased without delay in the change processing.

Further, in the invention according to claim 4, the length of the switching time is a length that sets the duty ratio to 50%. In such a configuration, the time required for the above-described on-time change processing, that is, the length of the switching time is uniquely set based on the duty ratio regardless of the processing capability of the device, so that setting of the switching time for each device is unnecessary. Become.

According to a fifth aspect of the present invention, there is provided a light control device for controlling a duty ratio of a pulse voltage supplied to a light source by changing an on-time within one cycle, the control device including the above-described control means. It was assumed.

With this configuration, even in a device in which the on-time changing process is slow, the correct time, that is, the duty ratio can always be set without delay in the changing process in controlling the duty ratio of the pulse voltage supplied to the light source. . Further, the duty ratio can be smoothly increased and decreased.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a control system for electric components in a vehicle compartment in a one-box vehicle equipped with a light control device according to the present invention, wherein a front seat air-conditioner amplifier 1 stored inside an instrument, Rear multi-remote control amplifier 2 stored in the upper part of the seat and connected to front air conditioner amplifier 1 via first communication line L1 and second communication line L2.
It is composed mainly of.

The front seat air-conditioning amplifier 1 has an audio 3,
The front air conditioner amplifier 1 controls the front air conditioner 4 and the rear air conditioner 5, and the front air conditioner amplifier 1 includes a room temperature sensor and an outside air temperature sensor for obtaining information necessary for controlling the front and rear air conditioners 4 and 5. Various sensors 6 for controlling the air conditioner are connected. Further, the rear-seat multi-remote control amplifier 2 includes an infrared remote control receiving unit 7 connected to the front seat air-conditioning amplifier 1 via a first communication line L1, and a control unit connected via a second communication line L2. 8, a serial / parallel conversion driver 9 and a tube light display unit 10 connected to both the control unit 8 and the serial / parallel conversion driver 9.

The infrared remote control receiving section 7 receives serial communication data transmitted from the infrared remote control unit 11,
That is, it has a function of receiving operation signals of the air conditioner, sunroof, audio, and room lamp, and transmitting the received data to the front seat air conditioner amplifier 1 via the first communication line L1. The tube light display unit 10 has a sunroof / lock indicator 10a and an air conditioner display unit 10b that are exposed inside the vehicle. The sunroof / lock indicator section 10a is a section for displaying the lock state of the sunroof based on the display signal sent from the control section 8, and the air conditioner display section 10b is connected to the second communication line L
2 is a part for displaying the setting contents of the rear air conditioner 5 based on a display signal sent from the front seat air conditioner amplifier 1 via the front air conditioner 2.

The control unit 8 includes a CPU (not shown), a ROM in which a control program of the CPU and various parameters are stored, and an R which stores various data in accordance with the operation of the CPU.
It has an input / output device including an AM, a timer, an A / D converter, a D / A converter, and the like, and functions as an output pulse control device and a light control device of the present invention by operating based on the control program. . The control unit 8 includes a front sunroof switch 12, a rear lamp main switch 13, an all-door switch 14, a room lamp switch 15, a sunroof drive block 16, a sunroof lock switch 17, and a room lamp 18 provided in the vehicle interior. Each is connected. The room lamp switch 15 is, specifically, an on / off switch or a light / dark switch.

In the present embodiment having the above configuration, when the rear lamp / main switch 13 is operated, the control unit 8 turns on / off the room lamp switch 15 or modulates the brightness by pulse width modulation. Adjust according to the method. When any of the doors is opened and detected by the room lamp switch 15, the control unit 8 turns on the room lamp 18, and then the opened door is fully closed again. When the brightness is detected by 15, the brightness of the room lamp 18 is dimmed by a pulse width modulation method.

Next, the specific operation content when the control unit 8 controls the brightness of the room lamp 18 as described above will be described with reference to the flowchart of FIG. That is, when the control of the brightness is started, the control unit 8 first determines whether or not the duty ratio of the output pulse should be changed (increased or decreased) (S1). That is, at the time of the above-described dimming control, it is determined whether or not a certain time determined in accordance with the sensitivity of the human eye to a change in brightness has elapsed. Also,
At the time of dimming according to the operation of the rear lamp / main switch 13, it is determined whether or not the operation amount has changed by a (very small) constant amount.

Here, if there is no need to change, the processing is once ended and the operation shifts to the control operation of another device such as a sunroof. Thereafter, if the time when the processing is started again is the time when the duty ratio should be changed (YE in S2)
S), it is determined whether the next duty ratio to be changed is 50% or more (S2). Here, if it is 50% or more (YES in S1), the duty ratio is changed at the rising edge of the output pulse (S3). That is, as shown in FIG. 3, the on-time t1 in one cycle T of the output pulse is changed at the rising point A of the output pulse, and the process of storing the same is performed. On the other hand, if the next duty ratio to be changed becomes 50% or less as time elapses (N2 in S2)
O) Then, the duty ratio is changed at the falling edge of the output pulse (S4). That is, as shown in FIG.
The on-time t1 within one cycle T of the output pulse is changed at the falling point B of the output pulse, and a process of storing the changed time is performed. Then, the above operation is repeated until the duty ratio becomes 0% (ON time is 0), for example, during dimming.

Here, in the above operation, when the duty ratio becomes 50% or less, the ON time t1 of the next cycle is reduced.
Is switched from the rising point A of the output pulse to the falling point B, so that when the light is dimmed after the door is fully closed, the on-time is gradually reduced in the process of gradually reducing the duty ratio. Even after the time t1 becomes shorter than the time t2 required to change the time t2, the short ON time t1 can be set irrespective of the arithmetic processing speed of the control unit 8 (CPU constituting the control unit 8), It changes smoothly until the duty ratio of the output pulse becomes 0%. Therefore, as shown in FIG. 4, at the time of dimming after the door is fully closed, the room lamp 18 is turned off smoothly without flickering for a moment even immediately before turning off.

Conversely, when the duty ratio becomes 50% or more, the set time of the on-time t1 in the next cycle is switched from the falling point B of the output pulse to the rising point A.
When the room lamp 18 in the unlit state is gradually brightened in accordance with the operation of the rear lamp main switch 13,
After starting the lighting based on the length of the ON time t1 (extremely short length) set at the beginning of the control, when the lighting time is subsequently changed to the longer ON time t1, the length is changed to the changing process. Even if the time is shorter than the required time t2, the ON time t1 can be changed regardless of the arithmetic processing speed of the control unit 8 (CPU constituting the control unit 8). Therefore, when the room lamp 18 in the unlit state is gradually brightened, the brightness of the room lamp 18 is set to a duty ratio of 10
Just before it reaches 0%, it flickers for a moment and then does not become brighter.

In other words, in the present embodiment, the brightness of the room lamp 18 can be changed immediately before the output pulse duty ratio becomes 0%, and regardless of the processing capability of the device that generates the output pulse. Has a duty ratio of 10
Immediately after reaching 0%, it is possible to adjust smoothly. In addition, since the on-time t1 can be set to be shorter than the time t2 required for the process of changing the on-time t1, the change in the brightness of the room lamp 18 can be very finely changed if necessary. further,
The above effects can be obtained irrespective of the arithmetic processing speed of the control unit 8. Therefore, by using a CPU having a low processing capacity, that is, an inexpensive CPU for the control unit 8, it is possible to reduce the cost of the system described above. is there.

In the present embodiment, a case has been described in which the setting time of the ON time t1 in the next cycle is switched between the rising point A and the falling point B of the output pulse with reference to the duty ratio of 50%. However, the present invention is not limited to this, and a certain switching time is set in advance in accordance with the arithmetic processing speed of the control unit 8 (CPU constituting the control unit 8), and the length of the ON time t1 is set to be longer than the length of the switching time. Accordingly, the setting time of the ON time t1 in the next cycle may be switched. Further, as shown in the present embodiment, in the case where the set timing is switched based on the duty ratio of 50%, C
The same control program can be used for the portion related to the dimming function even when the processing capacity of the PU and the number or content of the above-described interrupt processing of the control unit 8 are different. Therefore, there is an advantage that the design of the control unit 8 is easy and the design change can be easily dealt with.

Further, in the present embodiment, the case where the present invention is applied to a dimming device for a room lamp of an automobile has been described. In addition to this, other output pulse control for controlling the duty ratio of the output pulse is performed. The present invention may be used in an apparatus. Even in this case, the duty ratio of the output pulse can be minutely changed or the duty ratio can be smoothly changed regardless of the processing capability of the device.

[0029]

As described above, in the output pulse control device according to the first aspect, when the ON time within one cycle is changed, the length of the ON time to be changed is compared with the length of the preset switching time. Based on the control, the on-time change timing is controlled at the rising and falling points of the output pulse,
The correct time is always set without delay in the change process even in a device whose on-time change process is slow. Therefore, it is possible to precisely control the duty ratio of the output pulse regardless of the processing capability of the device.

In the output pulse control device according to the second aspect, the length of the switching time is uniquely set based on the duty ratio regardless of the processing capability of the device.
It is no longer necessary to set the switching time for each device. Therefore, the design of the output pulse control device of the first aspect is facilitated.

In the output pulse control device according to the third aspect, when the on-time within one cycle is sequentially changed, the time required for the on-time change processing to be changed is set, thereby changing the on-time. Even in a device having a slow processing, the on-time can be smoothly increased or decreased without delay in the change processing. Therefore, regardless of the processing capacity of the device,
The controllability when sequentially reducing the duty ratio of the output pulse is improved.

In the output pulse control device according to the fourth aspect, the length of the switching time is uniquely set based on the duty ratio regardless of the processing capability of the device.
It is no longer necessary to set the switching time for each device. Therefore, the design of the output pulse control device of the third aspect is facilitated.

In the light control device of the fifth aspect, even in a device in which the on-time changing process is slow, a delay occurs in the changing process when controlling the duty ratio of the pulse voltage supplied to the light source. The correct time, that is, the duty ratio can always be set. Also, the duty ratio can be smoothly increased and decreased. Therefore,
Regardless of the processing capability of the device, fine adjustment can be performed immediately before the duty ratio of the output pulse becomes 0% and immediately before the duty ratio of the output pulse becomes 100%.

[0034]

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation related to control of the brightness of a room lamp in a control unit.

FIG. 3 is a diagram showing a setting time of an ON time of an output pulse.

FIG. 4 is a diagram showing a change in brightness of a room lamp.

FIG. 5 is a diagram showing a change in an output pulse in the related art.

FIG. 6 is a diagram showing a change in brightness of a room lamp according to the related art.

FIG. 7 is a diagram showing a change of an output pulse showing a problem of the related art.

FIG. 8 is a diagram showing a change in brightness of a room lamp showing a problem of the related art.

[Explanation of symbols]

 8 control unit (output pulse control device, dimming device) 18 room lamp

Claims (5)

[Claims] 1. An output pulse control device for controlling a duty ratio of an output pulse, comprising: comparing a length of an on-time to be changed with a length of a preset switching time in accordance with a change of an on-time within one cycle;
When the former is longer, the change time of the on-time is set to the rising point of the output pulse, while when the latter is longer, the change time of the on-time is set to the falling point of the output pulse. An output pulse control device comprising means. 2. The output pulse control device according to claim 1, wherein the length of the switching time is such that the duty ratio is 50%. 3. An output pulse control device for controlling a duty ratio of an output pulse, wherein an on-time in one cycle is sequentially changed, and a length of the on-time to be changed becomes a preset switching time. Accordingly, when the on-time is reduced, the setting time of the length of the on-time is switched from the rising time of the output pulse to the falling time, while when the on-time is increased, the setting time of the length of the on-time is changed. An output pulse control device, comprising: control means for switching the time from the falling point of the output pulse to the rising point. 4. The output pulse control device according to claim 3, wherein the length of the switching time is a length with the duty ratio being 50%. 5. A light control device for controlling a duty ratio of a pulse voltage supplied to a light source by changing an ON time within one cycle, wherein the control means according to claim 1 is provided. A light control device, comprising: