JP2004351943A - Displaying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displaying device of a good visibility by changing the displaying brightness following a variation in illuminance. <P>SOLUTION: This displaying device is equipped with a luminescent type displaying apparatus 26 which can change the displaying brightness, an illuminance detecting means 18 which outputs a detected value (x) in response to the external light illuminance as a detection signal X, and a microcomputer 20 which outputs a control brightness value (y) which is calculated based on the detected value (x) and an adjusted value (w) as a control signal Y, and controls the displaying brightness of the luminescent type displaying apparatus 26 on a vehicle. The microcomputer 20 has a RAM 22 which stores the control brightness value (y) which is output as the control signal Y as a reference brightness value (z). A target brightness value (t) is calculated based on the detected value (x) which is newly detected by the illuminance detecting means 18, and a difference between the reference brightness value (z) and the target brightness value (t) is determined. An adjusted value (w) by which the control brightness value (y) becomes closer to the target brightness value (t) as the difference becomes larger is determined, and the control brightness value (y) based on the adjusted value (w) is calculated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a display device, and more particularly to a display device for adjusting the luminance of a light-emitting display.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a display device that automatically adjusts the luminance of a light-emitting display device such as a fluorescent display tube according to the surrounding illuminance. For example, a display device including a head-up display detects, with an optical sensor, the brightness in front of the vehicle, which is the background of a display image projected on the windshield of the vehicle, and controls the front in accordance with the detected brightness in front of the vehicle. By controlling the brightness of the display image projected on the glass, the display brightness is increased when the front of the vehicle is bright, and the display brightness is reduced when the vehicle is dark, so that the display is easy to see ( For example, see Patent Document 1).
[0003]
Also, in the case where the sunshine enters in some places while the vehicle is running, if the display brightness value of the display device according to the brightness value in front of the vehicle detected by the optical sensor is large, the display brightness value is large. Since the display changes and repeats, the driver feels that the display flickers. Therefore, there is a display device in which flicker is reduced by providing a control means for slowly changing the display luminance (for example, see Patent Reference 2).
[0004]
[Patent Document 1]
JP-A-61-42333 [Patent Document 2]
JP-A-11-319772
[Problems to be solved by the invention]
However, in such a display device, by gradually changing the display luminance, it is possible to provide a display with reduced flicker and improved visibility, but when the illuminance in front of the vehicle changes rapidly, a good display luminance is obtained. However, it takes a long time to perform the reading, and there is a problem that visibility is not good during that time.
[0006]
The present invention has been made in view of the above-described problem, and has as its object to provide a display device with good visibility by changing display luminance in accordance with a change in illuminance.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, a display device according to the present invention includes a light-emitting display device capable of changing display brightness and an illuminance detection device that outputs a detection value according to external light illuminance as a detection signal. A display device comprising: a vehicle; and a control unit that outputs a control luminance value calculated based on the detected value and the adjustment value as a control signal, and controls display luminance of the light emitting display. The control unit includes a storage unit that stores the control luminance value output as the control signal as a reference luminance value, and calculates a target luminance value based on a detection value newly detected by the illuminance detection unit. The difference between the reference luminance value and the target luminance value is determined, and the larger the difference is, the more the control luminance value is closer to the target luminance value. Calculate control brightness value Be Te is characterized in.
[0008]
According to another aspect of the present invention, there is provided a display device, comprising: a light-emitting display device capable of changing display luminance; illuminance detection means for outputting a detection value corresponding to illuminance as a detection signal; Control means for calculating a control luminance value of the light-emitting display based on the control luminance value, and controlling the display luminance of the light-emitting display device based on the control luminance value, the control means comprising: A storage unit that stores the control brightness value as a reference brightness value, calculates a target brightness value based on the newly detected detection value, compares the reference brightness value with the target brightness value, The control brightness value is calculated according to a result.
[0009]
According to a third aspect of the present invention, in the display device according to the second aspect, the control unit sets a display luminance of the light-emitting display device suitable for an illuminance based on the detected value. The control brightness value is calculated as a brightness value, and the control brightness value is calculated so as to be a value between the reference brightness value and the target brightness value.
[0010]
In addition, as described in claim 4, in the display device according to claim 3, the control unit is configured to control the target luminance when a difference between the reference luminance value and the target luminance value is small in the comparison result. A control brightness value is calculated so as to be a display brightness closer to the reference brightness value than the reference brightness value, and when a difference between the reference value and the target brightness value is large, a display closer to the target brightness value than the reference brightness value is calculated. It is characterized in that a control luminance value is calculated so as to be a luminance, and the display luminance of the light emitting display is controlled.
[0011]
The display device according to the present invention, as described in claim 5, is a light-emitting display device capable of changing display luminance, illuminance detection means for outputting a detection value according to external light illuminance as a detection signal, A control unit that outputs a control luminance value calculated based on the control value as a control signal, and controls a display luminance of the light-emitting display device, wherein the control unit includes the control signal A storage unit for storing the control luminance value output as a reference luminance value, calculating a target luminance value based on a detection value newly detected by the illuminance detection unit, and calculating the target luminance value and the target luminance value. A difference between the control luminance value and the target luminance value is determined in such a manner that the larger the difference is, the shorter the control luminance value approaches the target luminance value.
[0012]
In addition, the display device of the present invention, as described in claim 6, is a light-emitting display device capable of changing display luminance, illuminance detection means for outputting a detection value according to external light illuminance as a detection signal, A control unit that outputs a control brightness value calculated based on the value and the adjustment value as a control signal, and a control unit that controls the display brightness of the light-emitting display device. A storage unit that stores the control luminance value output as a control signal as a reference luminance value, calculates a target luminance value based on a detection value newly detected by the illuminance detection unit, and calculates the target luminance value and the reference luminance value. The light-emitting display is compared with a target luminance value, and the control luminance value is approximated or equal to the target luminance value at the adjustment value according to the magnitude relationship between the reference luminance value and the target luminance value. Display brightness And it is characterized in that made by us.
[0013]
Further, as described in claim 7, in the display device according to claim 6, when the reference luminance value is higher than the target luminance value, the control unit performs the control based on the first adjustment value. Controlling the display luminance of the light-emitting type display, and, when the reference luminance value is lower than the target luminance value, the light-emitting type display based on a second adjustment value that promotes a luminance change smaller than the first adjustment value. The display brightness of the display is controlled.
[0014]
Further, as described in claim 8, in the display device according to any one of claims 1 to 7, the illuminance detection means is prepared so that different detection characteristics can be selected. Is what you do.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described as an example in which the present invention is applied to a head-up display for a vehicle.
[0016]
As shown in FIG. 1, A is a display unit, and this display unit A is disposed in the dashboard 1 of the vehicle, and the display light L projected by the display unit A is applied to the viewer 3 by the windshield 2. Reflected in the direction. The observer 3 can observe the virtual image 4 while superimposing it on the scenery.
[0017]
FIG. 2 is a sectional view of the display unit A. Reference numeral 5 denotes a light-emitting element composed of a light-emitting diode. The light-emitting element 5 has a liquid crystal display element 6 on the illumination direction side and emits display light L. Reference numeral 7 denotes a circuit board, and the circuit board 7 is connected to the light emitting element 5 and the liquid crystal display element 6. A microcomputer described later is mounted on the circuit board 7.
[0018]
Reference numeral 11 denotes a housing. The housing 11 accommodates the light emitting element 5, the circuit board 7, and the like. An opening 12 from which the display light L is emitted is provided in the housing 11, and a light-transmitting cover 13 made of a light-transmitting resin (eg, acrylic) is provided in the opening 12. A reflecting mirror 14 reflects the display light L in the direction of the opening 12. Reference numeral 15 denotes a light-shielding wall. The light-shielding wall 15 is formed integrally with the housing 11 to prevent external light such as sunlight from being incident on the liquid crystal display element 6 and making the virtual image 4 difficult to see (washout). ing. The light shielding wall 15 is provided with a through hole 16 formed at a position facing an optical sensor described later. Reference numeral 17 denotes an optical sensor, which detects light transmitted through the translucent cover 13 and passed through the through hole 16. The optical sensor 17 is provided behind the light blocking wall 15 and is connected to the circuit board 7.
[0019]
Next, adjustment of the luminance of the light emitting element 5 will be described based on the block diagram shown in FIG. Reference numeral 18 denotes illuminance detection means. The illuminance detection means 18 includes an optical sensor (for example, a photo sensor) 17 and an A / D converter 19. The A / D converter 19 converts the illuminance signal W output from the optical sensor 17 as a detection value, and outputs the detection value to the microcomputer (control means) 20 as a detection signal X. Note that the detection value is an integer and is set according to the level of the illuminance signal W.
[0020]
The microcomputer 20 includes a CPU (Central Processing Unit) 21 as a means for performing various arithmetic processes based on the detection signal X from the illuminance detecting means 18, and a readable and rewritable work for temporarily storing the arithmetic processing results in the CPU 21. A RAM (storage unit) 22 serving as a memory and a ROM 23 serving as a read-only program memory storing a control program are provided. Further, the microcomputer 20 includes an input / output interface for electrically connecting to the illuminance detecting means 18 and a driving circuit.
[0021]
Further, the CPU 21 calculates a target luminance value of the light emitting element 5 according to the detection signal X from the illuminance detecting means 18 according to the program data stored in the ROM 23, and sets the target luminance value as a control signal Y to the drive circuit 24. Output, and the display brightness of the light emitting element 5 can be adjusted. In addition, the microcomputer 20 can drive and control the liquid crystal display element 8 in which a polarizing member is attached to the front and rear surfaces of a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates via a driving circuit 25. The RAM 22 temporarily stores (stores) the target luminance value as a reference value. The light emitting element 5 and the liquid crystal display element 8 constitute a light emitting display 26.
[0022]
Next, a control method by the microcomputer 20 until the control signal Y is output will be described based on the flowchart shown in FIG.
[0023]
The microcomputer 20 inputs a detection value x from a detection signal X generated by the illuminance detection means 18. Further, the microcomputer 20 inputs the control luminance value output as the previous control signal Y stored in the RAM 22 as the reference luminance value z (Step S1).
[0024]
The microcomputer 20 calculates a target luminance value t based on the detection value x input in step S1 (step S2). Note that the target luminance value t is determined by referring to a data table set in advance corresponding to the detection value x and extracting a value corresponding to the detection value x. This data table is set in advance according to the correspondence between the illuminance in front of the vehicle (illuminance based on the detected value x) and the display luminance of the display device that is easy for the driver to visually recognize at this illuminance, and is stored in the ROM 23.
[0025]
The microcomputer 20 compares the target luminance value t with the reference luminance value z to obtain a difference (Step S3).
[0026]
The microcomputer 20 determines an adjustment value (variable) w according to the difference (step S4). Note that the adjustment value w is used to calculate the control luminance value y, and a data table prepared in advance according to the difference between the target luminance value t and the reference luminance value z divided into gradations is used. It is determined by using. For example, if the difference is in the range of v1 to v2, the adjustment value w1 is determined by a data table as shown in FIG. The adjustment value w is set to a value that encourages the control luminance value y to be closer to the target luminance value t than the reference luminance value z as the difference is larger. The value y is set to a value urging the reference luminance value z to be closer to the reference luminance value z than the target luminance value t, forming a data table, and is stored in the ROM 23.
[0027]
The microcomputer 20 calculates a predetermined arithmetic expression using the adjustment value w calculated in step S4, the target luminance value t obtained from the detected value x, and the reference luminance value z stored in the RAM 22. The control luminance value y is calculated (step S5). The control luminance value y is set to be a value between the target luminance value t and the reference luminance value z. For example, when the data table is set such that the smaller the difference is, the larger the adjustment value w becomes, the control luminance value y may be calculated by the calculation of y = z + ((t−z) / w). it can.
[0028]
Further, the microcomputer 20 outputs the control luminance value y obtained in step S5 to the drive circuit 24 as a control signal Y (step S6). The drive circuit 24 controls the display luminance of the light emitting element 5 by performing PWM control based on the control signal Y. Further, the microcomputer 20 updates the reference luminance value z by substituting the control luminance value y obtained in step S5 for the reference luminance value z (step S7).
[0029]
By repeating the processing from step S1 to step S7, the display brightness of the light emitting display 26 is automatically adjusted so as to perform display with good visibility according to the illuminance in front of the vehicle. The display device is capable of performing the following operations. Further, by calculating the control luminance value y using the adjustment value w, the display luminance can be smoothly changed, and the flicker can be reduced.
[0030]
Such a display device is based on a light-emitting display device 26 capable of changing display luminance, an illuminance detection unit 18 that outputs a detection value x corresponding to external light illuminance as a detection signal X, and a detection value x and an adjustment value w. A microcomputer that outputs the calculated control luminance value y as a control signal Y and controls the display luminance of the light-emitting display 26; and the microcomputer 20 outputs the control signal Y as the control signal Y It has a RAM 22 for storing the control luminance value y as a reference luminance value z, calculates a target luminance value t based on the detection value x newly detected by the illuminance detecting means 18, and obtains the reference luminance value z and the target luminance value t. The adjustment value w is determined such that the control brightness value y is closer to the target brightness value t as the difference is larger, and the control brightness value y is calculated based on the adjustment value w.
[0031]
Therefore, since the control brightness value y is calculated based on the adjustment value w determined according to the difference, the display brightness of the light emitting display 26 can be changed according to the amount of change in the illuminance in front of the vehicle. Even when the illuminance in front of the vehicle suddenly changes, it does not take a long time until a good display luminance is obtained as in the related art, and the visibility is improved by the display luminance following the change in the illuminance. The display device performs good display.
[0032]
Further, the microcomputer 20 has a RAM 22 for storing the control luminance value y output as the control signal Y as the reference luminance value z, and determines the target luminance value t based on the detection value x newly detected by the illuminance detection means 18. By calculating and calculating the difference between the reference luminance value z and the target luminance value t, the control luminance value y is controlled so as to approximate the target luminance value t in a shorter time as the difference is larger. When the illuminance around the vehicle suddenly becomes dark, the light emission luminance of the light emitting element 5 can be weakened in a short time. It becomes a display device with good performance.
[0033]
In the embodiment of the present invention, the above-described head-up display for a vehicle has been described as an example. However, the present invention is not limited to this, and the configuration is not limited as long as a similar effect can be obtained. For example, the present invention may be applied to a light-emitting display device equipped with an organic EL element or the like. Further, the present invention may be applied to a liquid crystal display used as a display device of a navigation system.
[0034]
Further, in the above-described embodiment, an example in which the adjustment value w is determined using the data table has been described as an example. However, the present invention is not limited to this. May be obtained by a predetermined calculation based on
[0035]
Further, by providing an operation means such as a switch, a process of performing display control based on an adjustment value w according to a comparison result between the reference luminance value z and the target luminance value t as described above, and performing the above-described process Instead, it is also conceivable that the processing for controlling the display luminance by a luminance change based on a predetermined adjustment value (fixed value) can be selected according to the driver's preference.
[0036]
In the above-described embodiment, the adjustment value w is determined using the table data as shown in FIG. 5. However, for example, two types of table data are prepared, and the external light is changed from light to dark. These table data can be properly used depending on whether the table data changes from dark to bright. In this case, the microcomputer 20 compares the reference luminance value z with the target luminance value t, and uses two types of table data according to the magnitude relation between the reference luminance value z and the target luminance value t, so that external light can be reduced. The time (response time) until the display luminance of the light emitting display 26 approximates the target luminance value can be made different between when the display changes from light to dark and when the display changes from dark to light.
[0037]
Therefore, when the reference luminance value z becomes higher than the target luminance value t due to the change of the external light from light to dark, the microcomputer 20 calculates the control luminance value newly calculated using the first table data. Controls the display brightness of the light emitting display 26 with a first adjustment value such that the responsiveness becomes faster until the target brightness value approaches the target brightness value t. When the brightness value z becomes lower than the target brightness value t, the brightness value is newly calculated using the second table data (table data in which an adjustment value w that promotes a brightness change smaller than the first table data is set). The display brightness of the light-emitting display 26 can be controlled by a second adjustment value such that the response becomes slower than the first adjustment value until the control brightness value approaches the target brightness value t. . Thus, the display of the light-emitting display 26 can be performed in accordance with various conditions according to the specifications of the light-emitting display 26 and the specifications of other components. Further, it is possible to provide a display device with good visibility in which the display luminance of the light emitting display 26 is not too bright or too dark with respect to changing external light.
[0038]
Further, the illuminance detecting means 18 can connect a variable resistor to the optical sensor 17 in series and change the resistance value of the variable resistor to obtain a different detection characteristic (sensitivity) of the optical sensor 17 in a selectable manner. it can. Therefore, detection can be performed for a wide range of illuminance. Also, instead of the variable resistor, a plurality of resistors having different resistance values are provided, and the connection between each resistor and the optical sensor 17 is switched by switching means such as a switch element to change the detection characteristic. be able to. Further, it is possible to provide a display device adaptable to various situations, for example, by selecting detection characteristics suitable for day and night.
[0039]
【The invention's effect】
The present invention provides a light-emitting display device capable of changing display luminance, illuminance detection means for outputting a detection value corresponding to illuminance as a detection signal, and calculating a control luminance value of the light-emitting display device based on the detection value. And control means for controlling the display luminance of the light-emitting display based on the control luminance value, wherein the display luminance is changed by following the change in illuminance, thereby improving the visibility. A good display device can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing a display device mounted on a vehicle according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the display unit according to the embodiment;
FIG. 3 is a block diagram showing the embodiment.
FIG. 4 is a flowchart showing a processing procedure of a microcomputer in the embodiment.
FIG. 5 is a diagram showing table data.
[Explanation of symbols]
Reference Signs List 5 light emitting element 6 liquid crystal display element 18 illuminance detection means 20 microcomputer (control means)
22 RAM (storage unit)
26 Light-emitting display t Target luminance value w Adjustment value x Detection value y Control luminance value z Reference luminance value X Detection signal Y Control signal

Claims (8)

A light-emitting display device capable of changing display luminance, illuminance detection means for outputting a detection value corresponding to external light illuminance as a detection signal, and a control luminance value calculated based on the detection value and the adjustment value as a control signal A control device for outputting and controlling the display luminance of the light-emitting display device, comprising:
The control unit has a storage unit that stores the control luminance value output as the control signal as a reference luminance value, and calculates a target luminance value based on a detection value newly detected by the illuminance detection unit, The difference between the reference luminance value and the target luminance value is obtained, and the larger the difference is, the more the control luminance value is closer to the target luminance value. The adjustment value is determined, and the control based on the adjustment value is performed. A display device characterized by calculating a luminance value. A light-emitting display device capable of changing display brightness, illuminance detection means for outputting a detection value corresponding to the illuminance as a detection signal, and calculating a control brightness value of the light-emitting display device based on the detected value; Control means for controlling the display brightness of the light emitting display based on the brightness value, a display device comprising:
The control unit has a storage unit that stores the control luminance value as a reference luminance value, calculates a target luminance value based on a newly detected detection value, and calculates the reference luminance value and the target luminance value. A display device for comparing and calculating the control luminance value according to the comparison result. The control means calculates a display luminance of the light-emitting display device suitable for an illuminance as the target luminance value based on the detection value, and calculates a value between the reference luminance value and the target luminance value. The display device according to claim 2, wherein the control luminance value is calculated so as to be as follows. The control means calculates a control luminance value such that when the difference between the reference luminance value and the target luminance value is small in the comparison result, the display luminance is closer to the reference luminance value than the target luminance value. When the difference between the reference value and the target luminance value is large, a control luminance value is calculated so that the display luminance is closer to the target luminance value than the reference luminance value, and the display luminance of the light-emitting display is calculated. The display device according to claim 3, wherein the display device is controlled. A light-emitting display device capable of changing display brightness, illuminance detection means for outputting a detection value according to external light illuminance as a detection signal, and outputting a control brightness value calculated based on the detection value as a control signal, Control means for controlling the display luminance of the light-emitting display, and a display device equipped with a vehicle,
The control unit has a storage unit that stores the control luminance value output as the control signal as a reference luminance value, and calculates a target luminance value based on a detection value newly detected by the illuminance detection unit, A display device, wherein a difference between the reference luminance value and the target luminance value is determined, and the control luminance value is controlled so as to approximate the target luminance value in a shorter time as the difference is larger. A light-emitting display device capable of changing display luminance, illuminance detection means for outputting a detection value corresponding to external light illuminance as a detection signal, and a control luminance value calculated based on the detection value and the adjustment value as a control signal Output, control means for controlling the display brightness of the light-emitting display, a display device comprising:
The control unit has a storage unit that stores the control luminance value output as the control signal as a reference luminance value, and calculates a target luminance value based on a detection value newly detected by the illuminance detection unit, The reference luminance value is compared with the target luminance value, and the control luminance value is close to or equal to the target luminance value at the adjustment value according to the magnitude relationship between the reference luminance value and the target luminance value. The display device wherein the display luminance of the light emitting display is controlled as described above. When the reference luminance value is higher than the target luminance value, the control unit controls the display luminance of the light emitting display based on a first adjustment value, and the reference luminance value is higher than the target luminance value. The display brightness of the light-emitting display device is controlled based on a second adjustment value that prompts a change in brightness smaller than the first adjustment value when the brightness is lower than the first adjustment value. Display device. The display device according to any one of claims 1 to 7, wherein the illuminance detection means is prepared so that different detection characteristics can be selected.

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