JPWO2018123554A1 - Display device - Google Patents

Abstract

Provided is a display device capable of accurately controlling image display. The display device 100 includes an illumination unit 10 having a light source unit 11 that can emit light, an illumination control unit 91 that controls the illumination unit, a display element 30 that can form an image with illumination light C from the illumination unit 10, and a display element. 30, a display control unit 92 that controls 30, a first control unit 90-3 that controls the illumination control unit 91 with the illumination control data D <b> 1 based on the video signal 300, and a display element 30 and a display control unit 92 that are mounted in the first. 1 substrate CB1 and a second substrate CB2 on which the illumination control unit 91 is mounted. Preferably, the first controller 90-3 is further mounted on the second substrate CB2. Preferably, a second control unit 90-2 for determining a target output intensity is further mounted on the first substrate CB1.

Description

  The present invention relates to a display device that displays an image.

  For example, Patent Document 1 discloses a head-up display device as a display device, and the head-up display device includes a control board, a backlight board, and a liquid crystal driving board. The control board of patent document 1 can control a backlight board | substrate and a liquid crystal drive board | substrate, and can make a light source unit emit a meter image as display light.

  For example, Patent Literature 2 discloses a head-up display device, and the head-up display device includes a control board and a projector. The control board of patent document 2 can control a projector and make a passenger | crew visually recognize the virtual image of the image projected on the screen.

  For example, Patent Document 3 discloses a display device, and the display device includes a control unit, an illumination control unit, and a display control unit. The control part of patent document 3 can control an illumination control part and a display control part, and can make a passenger | crew visually recognize the virtual image of the light (display image) from a screen.

  More specifically, Patent Document 3 discloses a display device that displays an image by, for example, a field sequential method, and the display device includes an illumination device, a light intensity detection unit, an illumination optical system, a display element, A projection optical system, a screen, a plane mirror, a concave mirror, a housing, and a light transmitting part are provided. In the display device of Patent Document 3, the luminance of the illumination device can be changed according to the luminance required for the display image displayed on the screen. Specifically, the display device of Patent Document 3 adopts, for example, two driving methods as the driving method of the light source unit of the lighting device, and is necessary for the control value (for example, duty ratio) required for the PWM driving method and the PAM driving method. The brightness of the lighting device can be changed by changing the combination with a different control value (for example, current value).

  In the display device of Patent Document 3, the ratio of the display period (period in which the display element can display a display image on the screen) in the frame period may be constant (for example, 50 [%]). Alternatively, it may be determined (for example, 50 [%] or 70 [%]) according to the luminance required for the display image.

JP 2006-045388 A JP 2015-179152 A JP 2014-066920 A

  In general, the substrate constituting the display device is preferably a single substrate for simplification. However, in Patent Documents 1 and 2, a display device is configured by two or more substrates. In Patent Document 3, a circuit board in the lighting device is disclosed. However, a control unit, a lighting control unit, and a display control unit are provided. The specific substrate to be constructed is not disclosed. The inventors have recognized that it is desirable to prevent an increase in the number of substrates and to place appropriate circuit components on each substrate. In other words, the present inventors have recognized that it is desirable to determine the arrangement of circuit components so as not to cause problems in image display. In particular, when a DMD is adopted as a display element, the present inventors do not cause a problem in display in the DMD, specifically, in order not to affect the temperature of the DMD. Recognized that it is desirable to determine the placement.

  In Patent Document 3, it is suggested that light intensity data is obtained from the light intensity detection unit, and that the deviation between the luminance required for the display image displayed on the screen and the actual luminance of the illumination device (illumination unit) is corrected. However, a specific method is not disclosed.

  One object of the present invention is to provide a display device capable of accurately controlling the display of an image. Another object of the present invention is to provide a display device capable of accurately controlling the luminance of an illumination unit. Other objects of the present invention will become apparent to those skilled in the art by referring to the aspects and best embodiments exemplified below and the accompanying drawings.

  In the following, in order to easily understand the outline of the present invention, embodiments according to the present invention will be exemplified.

In the first aspect, the display device comprises:
An illumination unit having a light source unit capable of emitting light;
An illumination control unit for controlling the illumination unit;
A display element capable of forming a display image with illumination light from the illumination unit;
A display control unit for controlling the display element;
A first control unit that controls the illumination control unit with illumination control data based on a video signal;
A first substrate on which the display element and the display control unit are mounted;
A second substrate on which the illumination control unit is mounted;
Is provided.

  In the first aspect, a display element capable of forming a display image is mounted on the first substrate, and an illumination control unit that controls an illumination unit having a light source capable of emitting light is mounted on the second substrate. Since the illumination control unit controls the illumination unit having the light source unit, the amount of heat generated by the illumination control unit generally increases in order to cause the illumination unit (light source unit) to emit light. In addition, the present inventors have recognized that the display quality on the display element depends on the temperature of the display element. In other words, in order to stabilize the operation of the display element, the present inventors prevent the heat from the illumination control unit from being transferred to the display element by mounting the illumination control unit and the display element on different substrates. did.

  Since the display control unit controls the display element, the wiring between the display element and the display control unit can be simplified by mounting the display element and the display control unit on the same substrate. Or a display element and a display control part can be efficiently electrically connected between mounting a display element and a display control part on the same board | substrate.

In a second aspect dependent on the first aspect,
The illumination control unit may include a driver that drives the light source unit.

  In the second aspect, the illumination control unit is a driver, and consumes a current to drive the light source unit, and thus easily generates heat. Therefore, in the second aspect, it is possible to prevent the heat from the driver from being transferred to the display element by mounting the driver and the display element on different substrates.

In a third aspect subordinate to the second aspect,
The illumination control unit may further include a driver drive power supply unit that supplies drive power for the driver.

  In the third aspect, the illumination control unit is a driver and a driver drive power supply unit, and the driver drive power supply unit is also a supply source of the drive power supply of the driver, and thus easily generates heat. Therefore, in the third aspect, by mounting the driver and driver driving power supply unit and the display element on different substrates, heat from the driver and driver driving power supply unit can be prevented from being transmitted to the display element.

In a fourth aspect subordinate to any one of the first to third aspects,
The first control unit may be further mounted on the first substrate.

Since the first control unit generates the illumination control data based on the video signal, in the fourth aspect, for example, the illumination control unit that is a driver and the first control unit are mounted on different substrates for illumination. It is possible to prevent heat from the control unit from being transmitted to the first control unit. In the fourth aspect, the wiring between the display control unit and the first control unit can be simplified by mounting the display control unit and the first control unit on the same substrate.

In a fifth aspect subordinate to any one of the first to fourth aspects, the display device includes:
A first detection unit for detecting a current output intensity of the light source unit;
You may prepare further,
The first control unit may store a control value corresponding to a target output intensity of the light source unit,
The first control unit may determine a correction value for correcting the control value based on a difference between the target output intensity and the current output intensity detected by the first detection unit,
The illumination control unit may drive the light source unit based on a control correction value in which the control value is corrected by the correction value.

  In the fifth aspect, for example, when the target output intensity is set or changed according to the change in the required luminance, the current output intensity corresponding to the target output intensity before setting or before changing can be taken into consideration. Specifically, in the fifth aspect, it is possible to consider how far the current output intensity is to the target output intensity after setting or changing. More specifically, in the fifth aspect, when the light source unit is driven with a control value corresponding to the target output intensity after setting or changing, the control value is a distance from the current output intensity to the target output intensity. It can correct | amend by the correction value based on. Accordingly, the current or actual output intensity after driving can easily coincide with the target output intensity after setting or changing, and the luminance of the illumination unit can be accurately controlled.

In the fifth aspect, for example,
When the target output intensity is lower than the current output intensity, the correction value may decrease the control value.

  In the fifth aspect, for example, when the current output intensity is lowered to the target output intensity after setting or changing, the light source unit can be driven with the reduced control value. Specifically, when the first control unit stores a control value corresponding to the target output intensity, the light source unit is driven with a control correction value corresponding to the target output intensity lower than the target output intensity after setting or changing. can do. In general, the higher the target output intensity, the higher the temperature of the light source unit. Therefore, when the current output intensity is lowered to the target output intensity after setting or changing, the luminance of the illumination unit is reduced due to the high temperature state of the light source unit. The present inventors have recognized that it is large. In the fifth aspect, for example, when the current output intensity is lowered to the set or changed target output intensity, the light source unit is driven with the reduced control value, so that the luminance of the illumination unit can be accurately controlled. it can.

In the fifth aspect, for example,
When the target output intensity is higher than the current output intensity, the correction value may increase the control value.

  In the fifth aspect, for example, when the current output intensity is raised to the target output intensity after setting or changing, the light source unit can be driven with the increased control value. Specifically, when the first control unit stores a control value corresponding to the target output intensity, the light source unit is driven with a control correction value corresponding to a target output intensity that is higher than the target output intensity after setting or changing. can do. Generally, the lower the target output intensity, the lower the temperature of the light source unit. Therefore, when the current output intensity is increased to the target output intensity after setting or changing, the luminance of the illumination unit is reduced due to the low temperature state of the light source unit. The present inventors have recognized that it is small. In the fifth aspect, for example, when the current output intensity is increased to the target output intensity after setting or changing, the light source unit is driven with the increased control value, so that the luminance of the illumination unit can be accurately controlled. it can.

In the fifth aspect, for example,
The absolute value of the correction value may be larger as the absolute value of the difference between the target output intensity and the current output intensity detected by the first detection unit is larger.

  In the fifth aspect, for example, as the distance from the current output intensity to the target output intensity increases, the light source unit is driven based on the correction value that is strongly corrected according to the distance. Can be controlled.

In the fifth aspect, for example,
When the absolute value of the difference between the target output intensity and the current output intensity detected by the first detection unit is smaller than a threshold value, the correction value may be zero, and the control correction value May be the control value corresponding to the target output intensity.

  In the fifth aspect, for example, when the distance from the current output intensity to the target output intensity is short, correction of the control value can be omitted, and the light source unit can be driven with the control value corresponding to the target output intensity.

In the fifth aspect, for example,
After driving the light source unit based on the control correction value, the first control unit may capture the current output intensity detected by the first detection unit, and the current output intensity is the target The correction value may be adjusted to match the output intensity.

  In the fifth aspect, for example, after driving the light source unit based on the control correction value, the current output intensity is captured, preferably the current output intensity is captured in real time, and the current or actual output intensity after driving is set. The correction value can be adjusted based on the coincidence or mismatch with the target output intensity after or after the change.

In the fifth aspect, for example,
The light source unit may include a plurality of light emitting elements each having a different emission color,
The illumination control unit may control the illumination unit in a field sequential manner so as to drive the different light-emitting elements for each subframe period obtained by dividing the frame period of the image.
The first control unit may store the control value corresponding to the target output intensity for each light emitting element,
The control value may be based on a multiplication value of a duty ratio for PWM driving one corresponding light emitting element among the plurality of light emitting elements and a current value for PAM driving the corresponding one light emitting element.

  In the fifth aspect, for example, in a field sequential display device, as a control value corresponding to the target output intensity, for example, a multiplication value of a duty ratio and a current value when driving one light emitting element is adopted. Can do.

In a sixth aspect subordinate to any one of the first to fifth aspects, the display device includes:
A second detection unit for detecting a current temperature of the light source unit;
You may prepare further,
The first control unit may determine the correction value based on the difference between the target output intensity and the current output intensity and the current temperature.

  In the sixth aspect, the current temperature of the light source unit can be further considered when determining the correction value. Therefore, the current or actual output intensity after driving can be more easily matched with the target output intensity after setting or changing, and the luminance of the illumination unit can be controlled more accurately.

In the sixth aspect, for example,
The first control unit may store an assumed temperature of the light source unit associated with the control value,
The first control unit determines the difference between the target output intensity and the current output intensity, the current temperature, a first assumed temperature associated with a current control value, and the target output intensity. The correction value may be determined based on the second assumed temperature associated with the corresponding target control value.

  In the sixth aspect, for example, when determining the correction value by associating the assumed temperature of the light source unit with the control value, the current temperature of the light source unit, the first assumed temperature before or before the change, and after installation or The second assumed temperature after the change can be further considered. Therefore, the current or actual output intensity after driving can be more easily matched with the target output intensity after setting or changing, and the luminance of the illumination unit can be controlled more accurately.

In a seventh aspect subordinate to the sixth aspect, the display device includes:
You may further provide the 3rd board | substrate with which the said light source part and the said 2nd detection part are mounted.

  In the seventh aspect, for example, by mounting the illumination control unit and the light source unit, which are drivers, on different substrates, heat from the illumination control unit can be prevented from being transmitted to the light source unit. In the seventh aspect, the light source unit and the second detection unit (detection unit for detecting the current temperature of the light source unit) are mounted on the same substrate, so that the space between the light source unit and the second detection unit is set. This wiring can be simplified.

In an eighth aspect subordinate to any one of the fifth to seventh aspects, the display device includes:
A second control unit for determining the target output intensity;
You may have more,
The second control unit may be further mounted on the second substrate.

  In the eighth aspect, since there is no problem in display on the display element, the illumination control unit and the second control unit can be mounted on the same substrate.

Eighth aspect dependent on the seventh aspect In the ninth aspect dependent on the seventh aspect,
Data representing the current temperature may flow through the wiring portion between the third substrate and the second substrate,
In the wiring part between the first substrate and the second substrate, the data representing the current temperature and the data representing the target output intensity may flow,
The second control unit may send the target output intensity and the current temperature to the display control unit,
The display control unit may send the target output intensity to the first control unit.

  In the ninth aspect, the second control unit mounted on the second substrate sends the target output intensity to the first control unit via the display control unit mounted on the first substrate. . In the ninth aspect, the second control unit sends the current temperature of the light emitting unit to the display control unit. Therefore, in the ninth aspect, between the second detection unit (detection unit for detecting the current temperature of the light source unit) mounted on the third substrate and the display control unit mounted on the first substrate. There is no need to provide a direct wiring portion, and workability is improved when the first substrate, the second substrate, and the third substrate are fixed and the display device is assembled.

  Those skilled in the art will readily understand that the illustrated embodiments according to the present invention can be further modified without departing from the spirit of the present invention.

It is explanatory drawing of one use of the display apparatus according to this invention. It is explanatory drawing of the display mechanism of the head-up display apparatus of FIG. 3A shows an example of the structure of a display device according to the present invention, and FIG. 3B shows an example of the arrangement of circuit components on each of a plurality of substrates constituting the display device of FIG. 4 is a flowchart illustrating an operation example of the display device in FIG. 3. It is explanatory drawing of the correction value which correct | amends the control value corresponding to target output intensity. It is explanatory drawing of the flame | frame which is a period which displays the display image of FIG. It is explanatory drawing of the drive method of the display element 30 and the light emission part 10 of FIG.

  The best mode described below is used to easily understand the present invention. Accordingly, those skilled in the art should note that the present invention is not unduly limited by the embodiments described below.

  FIG. 1 is an explanatory diagram of one application of a display device according to the present invention. In the example of FIG. 1, for example, a head-up display device 100 is shown as the display device, and the head-up display device 100 is suitable for a vehicle that is, for example, an automobile. The head-up display device 100 is provided in the dashboard of the vehicle, and the occupant such as the driver 250, for example, reflects the display light L representing the display image by the windshield 200, so that the driver 250 or the like is a virtual image of the display image representing the vehicle information. V can be visually recognized.

  FIG. 2 is an explanatory diagram of a display mechanism of the head-up display device 100 of FIG. In the example of FIG. 2, the head-up display device 100 includes, for example, an illumination unit 10, an illumination optical system 20, a display element 30, a detection unit 40 (see FIG. 3A), a projection optical system 50, A screen 60, a flat mirror 70, a concave mirror 75, and a housing 80 having a window portion 81 through which a display image M is emitted are provided.

  The illumination unit 10 in FIG. 2 includes a light source unit 11 (see FIG. 3B) capable of emitting light. For example, a circuit board (third substrate CB3) on which the light source unit 11 is mounted and a reflection / transmission optical unit ( And a luminance unevenness reducing optical unit (not shown). The light source unit 11 includes, for example, a light emitting diode 11r that emits red light (first light emitting element in a broad sense), a light emitting diode 11g that emits green light (second light emitting element in a broad sense), and blue light, for example. And a light emitting diode 11b (third light emitting element in a broad sense) that emits light (see FIG. 3A).

  When the light source unit 11 is composed of, for example, first to third light emitting elements, for example, the third substrate CB3 in FIG. 3B is composed of, for example, three substrates, and in one example, each substrate CB3. One light emitting unit 11 and one sensor 40t1 (temperature detection sensor) can be mounted. In other words, the light emitting unit 11 may be composed of a single light emitting element having a single color, and FIG. 3B conceptually shows at least one third substrate CB3.

  The illumination optical system 20 of FIG. 2 is configured by, for example, a concave lens or the like, and can adjust the illumination light C emitted from the illumination unit 10 to the size of the display element 30. The display element 30 in FIG. 2 is, for example, a DMD (Digital Micro-mirror Device) having a plurality of movable micromirrors, and each of the plurality of micromirrors is individually controlled. When the micromirror is ON, the micromirror is tilted, for example, by +12 degrees with a hinge (not shown) as a fulcrum, and can reflect the illumination light C emitted from the illumination optical system 20 in the direction of the projection optical system 50. . When the micromirror is OFF, the micromirror tilts, for example, -12 degrees with the hinge as a fulcrum, and cannot reflect the illumination light C in the direction of the projection optical system 50.

  The detection unit 40 in FIG. 3A can detect the output intensity of the light source unit 11 of the illumination unit 10, preferably can also detect the temperature of the light source unit 11, and more preferably, the display element 30. Can also be detected. In other words, the detection unit 40 in FIG. 3A is preferably configured by, for example, the sensor 40p (output intensity sensor) and the sensor 40t1 (temperature detection sensor) in FIG. 3B, and more preferably, for example, the sensor 40p, sensor 40t1, and sensor 40t2 (temperature detection sensor). The projection optical system 50 in FIG. 2 is configured with, for example, a concave lens or a convex lens, and can efficiently irradiate the screen 60 with the display light L of the display image M projected from the display element 30. The screen 60 in FIG. 2 includes, for example, a diffusing plate, a holographic diffuser, a microlens array, and the like. The display light L from the projection optical system 50 is received by the lower surface of the screen 60 and the display image M is displayed on the upper surface of the screen 60. Can be displayed.

  The plane mirror 70 in FIG. 2 can reflect the display image M displayed on the screen 60 toward the concave mirror 75. The concave mirror 75 in FIG. 2 is, for example, a concave mirror or the like, reflects the display light L from the flat mirror 70 on the concave surface, and the reflected light is emitted toward the window portion 81. The display light L reaches the driver 250 in FIG. 1 through such a display mechanism, and the virtual image V recognized by the driver 250 has an enlarged size of the display image M displayed on the screen 60. Have.

  The material of the housing 80 in FIG. 2 is, for example, hard resin or the like, and a window portion 81 having a predetermined size is provided above the housing 80. The material of the window part 81 of FIG. 2 is translucent resin, such as an acrylic, for example, and the shape of the window part 81 is a curved shape, for example. The window part 81 can transmit the display light L from the concave mirror 75.

  3A shows a configuration example of a display device according to the present invention, and FIG. 3B shows a circuit configuration in each of a plurality of substrates CB1, CB2, CB3, and CB4 constituting the display device of FIG. 3A. An example of arrangement of elements is shown. In FIG. 1, the display device is shown as a head-up display device 100, and the head-up display device 100 is controlled by, for example, the control unit 90, the illumination control unit 91, and the display control unit 92 in FIG. In the example of FIG. 3A, an ECU (Electronic Control Unit) generates a video signal 300, and the control unit 90 can input the video signal 300 by, for example, LVDS (Low Voltage Differential Signal) communication. . The control unit 90 is typically configured by, for example, an FPGA (Field Programmable Gate Array), but may be configured by an ASIC (Application Specific Integrated Circuit), a microcomputer, or the like. Moreover, the control part 90, the illumination control part 91, and the display control part 92 may be comprised by integrated IC, for example.

  The control unit 90 in FIG. 3A outputs illumination control data D1 for controlling the illumination unit 10 at the light luminance and emission timing required by the video signal 300 to the illumination control unit 91 and Display control data D <b> 2 for forming the requested display image M on the display element 30 can be output to the display control unit 92. A frame F, which is a cycle for displaying the display image M, is composed of subframes SF divided into a plurality of times (see FIG. 7), and the illumination control unit 91 in FIG. 3A is different for each subframe SF. The illumination unit 10 can be controlled by a field sequential drive method in which the color light emitting diodes 11r, 11g, and 11b are sequentially switched at high speed at the light intensity and timing required by the illumination control data D1.

  The display control unit 92 in FIG. 3A performs ON / OFF control of each micromirror of the display element 30 by, for example, the PWM method based on the display control data D2, and the illumination light C emitted from the illumination unit 10 is screened. When the light is reflected in the direction of 60, the display image M can be expressed in a color mixture by an additive mixing method or a full color using the light emitting diodes 11r, 11g, and 11b as basic colors. The detection unit 40 (specifically, sensor 40p (first detection unit)) in FIG. 3A includes a sensor 41 that is a photodiode, for example, and an A / D converter 42 that converts analog data into digital data. The output intensity data P of the light emitting unit 11 can be output to the control unit 90. The detection unit 40 (specifically, the sensor 40p) is provided for each of the light emitting diodes 11r, 11g, and 11b, and the sensor 41 can typically include three light intensity detection sensors.

  Preferably, the detection unit 40 (specifically, the sensor 40t1 (second detection unit)) of FIG. 3A also outputs the temperature data T of the light emitting unit 11 to the control unit 90, and the sensor 41 is typically Specifically, it can further include three temperature detection sensors corresponding to the three light emitting diodes 11r, 11g, and 11b. The temperature data T1 of the light emitting unit 11 is, for example, the ambient temperature of the light emitting diode or the LED chip, and the control unit 90 is based on the ambient temperature, the thermal resistance from the LED chip to the ambient atmosphere, and the input power. The junction temperature may be calculated.

  More preferably, the detection unit 40 (specifically, the sensor 40t2 (third detection unit)) in FIG. 3A also outputs the temperature data T2 of the display element 30, which is a DMD, to the control unit 90, for example. The sensor 41 can typically further include one temperature detection sensor corresponding to the display element 30.

  In the example of FIG. 3B, the third control unit 90-1 (specifically, the serial / parallel converter (S / P)) converts the video signal 300 (specifically, the serial video signal). Based on this, the display control unit 92 (specifically, the controller (DMD controller)) is controlled by the display control data D2 (specifically, the parallel video signal). The first control unit 90-3 (specifically, the power management IC (PMIC)) is based on the video signal 300 (specifically, the display control data D2), and the illumination control unit 91 (specifically, the driver). DRV (LED driver)) is controlled by illumination control data D1 (specifically, control value d). The second control unit 90-2 (specifically, the controller (micro controller)) can determine the target output intensity data p of the light emitting unit 11 based on the illuminance data, for example, The temperature data T1 can be relayed.

  The serial / parallel converter (S / P) is a video signal input unit in a broad sense, and the third control unit 90-1 or the video signal input unit inputs a parallel video signal from the ECU and inputs it. The parallel video signal may be sent to the display control unit 92 (DMD controller). Alternatively, the third control unit 90-1 may be omitted, and the display control unit 92 (DMD controller) may receive a parallel video signal from the ECU, and the display control unit 92 (DMD controller) The video signal input unit of the unit 90 may have a function.

  A display element 30 (DMD) and a display control unit 92 (DMD controller) are mounted on the first substrate CB1 in FIG. In addition, an illumination control unit 91 (LED driver) and a third control unit 90-1 (S / P) are mounted on the second substrate CB2. In this example, the display element 30 capable of forming the display image M is mounted on the first substrate CB1, while the illumination control unit 91 that controls the illumination unit 10 including the light source unit 11 that can emit light is the second substrate CB2. To be implemented. Since the illumination control unit 91 controls the illumination unit 10 having the light source unit 11, the amount of heat generated by the illumination control unit 91 generally increases in order to cause the illumination unit 10 (light source unit 11) to emit light. Further, the present inventors have recognized that the display quality on the display element 30 depends on the temperature (T2) of the display element 30. In other words, in order to stabilize the operation of the display element 30, the inventors mount the illumination control unit 91 and the display element 30 on different substrates so that heat from the illumination control unit 91 is applied to the display element 30. Prevented transmission.

  In particular, when the display element 30 is a DMD, the present inventors have recognized that a display failure in the DMD may occur at a high temperature (for example, 90 degrees Celsius or higher).

  By the way, since the third control unit 90-1 converts a serial video signal into a parallel video signal, the third control unit 90-1 has higher resistance to temperature than the display element 30. By mounting the illumination control unit 91 and the third control unit 90-1 on the same substrate, an increase in size of the head-up display device 100 can be suppressed. Alternatively, since there is no problem with the display on the display element 30, the illumination control unit 91 and the third control unit 90-1 can be mounted on the same substrate. When the third control unit 90-1 is a video signal input unit that inputs a parallel video signal from the ECU, the video signal input unit (third control unit 90-1) is compared with the display element 30. High resistance to temperature.

  Since the display control unit 92 controls the display element 30, the wiring between the display element 30 and the display control unit 92 is simplified by mounting the display element 30 and the display control unit 92 on the same substrate. be able to. Alternatively, the display element 30 and the display control unit 92 can be efficiently and electrically connected by mounting the display element 30 and the display control unit 92 on the same substrate.

  In the example of FIG. 3B, the illumination control unit 91 is, for example, an LED driver, and consumes current to drive the light source unit 11, and thus easily generates heat. Note that the illumination control unit 91 may further include a driver drive power supply unit (specifically, a DC / DC converter CNV) that supplies drive power for the LED driver. When the illumination control unit 91 is, for example, an LED driver and a driver drive power supply unit, the driver drive power supply unit is also a source of drive power for the LED driver, and thus easily generates heat. As an example, the DC / DC converter CNV can transform or step down a battery power source (for example, 12 [V]) to a voltage (for example, 8 [V]) driven by an LED driver.

  In the example of FIG. 3B, the first controller 90-3 may be further mounted on the first substrate CB1. The first control unit 90-3 is, for example, an LED driver because it generates illumination control data D1 (specifically, control value d) based on, for example, a parallel video signal (video signal 300 in a broad sense). By mounting the illumination control unit 91 and the first control unit 90-3 on different substrates, it is possible to prevent heat from the illumination control unit 91 from being transferred to the first control unit 90-3. Moreover, the wiring between the display control unit 92 and the first control unit 90-3 can be simplified by mounting the display control unit 92 and the first control unit 90-3 on the same substrate. .

  In the example of FIG. 3B, the second control unit 90-2 mounted on the second substrate CB2 passes through the display control unit 92 mounted on the first substrate CB1, and the target output intensity p Is sent to the first control unit 90-3. The third control unit 90-3 sends the current temperature (T 1) of the light emitting unit 11 to the display control unit 92. Therefore, in the head-up display device 100, the second detection unit (sensor 40t1 for detecting the current temperature data T1 of the light source unit 11) mounted on the third substrate CB3 and the display mounted on the first substrate CB1. There is no need to provide a direct wiring part between the control unit 92 and workability when the head-up display device 100 is assembled by fixing the first substrate CB1, the second substrate CB2, and the third substrate CB3. Will improve.

  A first detection unit (a sensor 40p that detects output intensity data P of the light emitting unit 11) is mounted on the fourth substrate CB4 in FIG. A third detection unit (a sensor 40t2 that detects current temperature data T2 of the display element 30) is mounted on the first substrate CB1. When the display element 30 is a DMD, since the DMD has low resistance to temperature, for example, a heater is further mounted on the first substrate CB1, for example, the display control unit 92 can relay the temperature data T2. . For example, when the temperature data T2 falls below the lower limit of the predetermined temperature range of the DMD, the second control unit 90-2 can increase the temperature of the DMD with a heater based on the temperature data T2. Alternatively, for example, when the temperature data T2 exceeds the upper limit of a predetermined temperature range of the DMD, the second control unit 90-2 can lower the temperature of the DMD with a fan based on the temperature data T2.

  The display control unit 92 can control each of the plurality of micromirrors constituting the DMD (display element 30) based on the parallel video signal with a high-speed signal path. Further, the display control unit 92 can execute or change the setting of the display element 30 through the low-speed signal path, and can read the setting value from the display element 30. Further, the display control unit 92 can calculate, for example, white balance information WH suitable for the temperature data T1 of the light emitting unit 11.

  The first control unit 90-3 is based on the difference between the target output intensity P of the light emitting unit 11 and the current output intensity p and the white balance information WH (temperature data T1 in a broad sense). The control value correction value corresponding to the target output intensity P can be determined, and the corrected control value d can be output to the illumination control unit 91. Further, for example, the current value of the light emitting unit 11 driven by the illumination control unit 91 that is an LED driver is fed back to the first control unit 90-3, and the first control unit 90-3 receives the feedback. The control value can be determined or adjusted based on it.

  FIG. 4 is a flowchart illustrating an operation example of the display device in FIG. For example, in step ST01, the control unit 90 (second control unit 90-2 in FIG. 3B) inputs a new dimming value. Typically, the vehicle or the head-up display device 100 of FIG. 1 includes an illuminance sensor that detects the illuminance of external light such as the illuminance of the front of the vehicle, and the control unit 90 requests the video signal 300 according to the illuminance data. The brightness of the light to be determined can be determined. In other words, the new dimming value is typically illuminance data, for example. Alternatively, the new dimming value may be determined by, for example, the ECU of FIG. 3A or another ECU not shown (in-vehicle device in a broad sense), or may be determined by the operation of the driver 250. Good.

  After the new dimming value is input, the control unit 90 (second control unit 90-2 in FIG. 3B) inputs the temperature of the light emitting unit 11 (for example, the temperature of the light emitting diode 11r that emits red light). (Step ST02 in FIG. 4). Next, the control unit 90 (second control unit 90-2 in FIG. 3B) determines the target output intensity of the light source unit 11 (for example, the target light intensity of the light emitting diode 11r) according to the new dimming value. (Step ST03). Next, the control unit 90 (the first control unit 90-3 in FIG. 3B) determines that the difference between the target output intensity set or changed based on the new dimming value and the current output intensity is a threshold (first It is determined whether or not (step ST04).

  When the difference between the target output intensity and the current output intensity is equal to or greater than the threshold, the control unit 90 (the first control unit 90-3 in FIG. 3B) determines the difference between the target output intensity and the current output intensity. Then, a correction value is determined based on the temperature of the light emitting unit 11 (step ST05). When the display device or the head-up display device 100 does not detect the temperature of the light emitting unit 11, step ST02 is omitted, and in step ST05, the control unit 90 (the first control unit 90-3 in FIG. 3B) is omitted. ) May determine the correction value based on the difference between the target output intensity and the current output intensity.

  FIG. 5 is an explanatory diagram of a correction value for correcting the control value corresponding to the target output intensity. The control unit 90 in FIG. 3 (first control unit 90-3 in FIG. 3B) stores a control value corresponding to the target output intensity of the light source unit 11, and corresponds to, for example, the target output intensity p1 and p2. The control values are d1 and d2, respectively (see FIG. 5). For example, the relational expression as shown in FIG. 5 is set at the time of manufacture in consideration of individual differences between the light emitting diodes 11r, 11g, and 11b. When the value of the target output intensity is changed from, for example, p1 in FIG. 5 to p2, the control unit 90 (the first control unit 90-3 in FIG. 3B) can consider the current output intensity. (Step ST05 in FIG. 4).

  For example, it is assumed that the current output intensity data P of the light emitting diode 11r matches the target output intensity p1, and the illumination control unit 91 drives the light emitting diode 11r with the control value d1. Specifically, the control unit 90 can consider how far the current output intensity (= p1) is far from the set or changed target output intensity p2. More specifically, when the illumination control unit 91 drives the light emitting diode 11r with the control value d2 corresponding to the target output intensity p2 after setting or changing, the control value d2 is set to the current output intensity (= p1). ) To the target output intensity p2 can be corrected by a correction value Δ based on the distance (= p1-p2).

  When the current output intensity (= p1) is lowered to the set or changed target output intensity p2, the illumination control unit 91 drives the light emitting diode 11r with the reduced control value (= d2−Δ = d2 ′). be able to. In other words, the illumination control unit 91 can drive the light emitting diode 11r with the control correction value d2 ′ corresponding to the target output intensity lower than the target output intensity p2 after setting or changing. Generally, the higher the target output intensity p, the higher the temperature of the light emitting diode 11r. Therefore, when the current output intensity (= p1) is lowered to the target output intensity p2 after setting or changing, the light emitting diode 11r is in a high temperature state (heat generation). The present inventors have recognized that the luminance of the light emitting diode 11r driven by the control value d2 is high due to the amount). In the illumination control unit 91 of FIG. 3, when the current output intensity (= p1) is lowered to the target output intensity p2 after setting or changing, the light emitting diode 11r with the reduced control value (= d2−Δ = d2 ′). Since the light source unit 11 is driven, the luminance of the illumination unit 10 can be accurately controlled.

  Preferably, the larger the absolute value of the difference between the target output intensity and the current output intensity is, the larger the absolute value of the correction value is set. That is, when the current output intensity (= p1) is lowered to the set or changed target output intensity (<p2), the illumination control unit 91 uses the light emitting diode 11r with a further reduced control value (<d2 ′). Can be driven. As the distance from the current output intensity to the target output intensity increases, the illumination control unit 91 drives the light source unit 11 based on the correction value that is strongly corrected according to the distance, and thus the control unit 90 (FIG. 3B ) First control unit 90-3) can control the luminance of the illumination unit 10 more accurately.

  In FIG. 5, the control value d is based on a product of a duty ratio for PWM driving one light emitting element such as the light emitting diode 11r and a current value for PAM driving the light emitting diode 11r. Electric power. As an example, when the duty ratio of PWM driving is constant, the control value d is the driving current of the light emitting diode 11. Alternatively, when the driving current is constant, the control value d is a duty ratio of PWM driving.

  For example, it is assumed that the current output intensity data P of the light emitting diode 11r matches the target output intensity p2, and the illumination control unit 91 drives the light emitting diode 11r with the control value d2. When the current output intensity (= p2) is increased to the target output intensity p1 after setting or changing, the illumination control unit 91 can drive the light emitting diode 11r with the increased control value (> d1). Specifically, when the control unit 90 (the first control unit 90-3 in FIG. 3B) stores a control value corresponding to the target output intensity, it is higher than the set or changed target output intensity. The light source unit can be driven with a control correction value corresponding to the target output intensity. Generally, the lower the target output intensity p, the lower the temperature of the light emitting diode 11r. Therefore, when the current output intensity (= p2) is increased to the target output intensity p1 after setting or changing, the light emitting diode 11r is in a low temperature state (heat generation). The present inventors have recognized that the luminance of the light emitting diode 11r driven by the control value d1 is small due to the amount). In the illumination control unit 91 of FIG. 3, when the current output intensity (= p2) is increased to the target output intensity p1 after setting or changing, the light source unit 11 such as the light emitting diode 11r with the increased control value (> d1). Is driven, the brightness of the illumination unit 10 can be controlled accurately.

  When the control unit 90 in FIG. 3 (first control unit 90-3 in FIG. 3B) stores a control value corresponding to the target output intensity of the light source unit 11, the light source unit 11 associated with the control value. Can be stored. For example, the assumed temperatures corresponding to the control values d1 and d2 are T1 and T2, respectively (see FIG. 5). In step ST02 of FIG. 4, for example, the temperature of the light emitting diode 11r is T. For example, the current output intensity data P of the light emitting diode 11r matches the target output intensity p1, and the illumination control unit 91 emits light with the control value d1. Assume that the diode 11r is driven. Specifically, the control unit 90 (the first control unit 90-3 in FIG. 3B) determines the current control value (= T1) and the current control value (= p1) corresponding to the current temperature (= T). How far the current temperature (= T) is from the current assumed temperature (= T1) when the difference from the assumed temperature (= T1) associated with d1) is greater than or equal to the threshold (second threshold or temperature threshold) Can be considered. More specifically, the control unit 90 (the first control unit 90-3 in FIG. 3B) determines whether the current temperature (= T), the current estimated temperature (= T1), or after setting or change. The estimated temperature T2 associated with the control value d2 corresponding to the later target output intensity p2 can be compared.

  When the current temperature (= T) is farther from the current assumed temperature (= T1) than the assumed temperature T2 after being set or changed, that is, when T <T2 <T1 is established, the control unit 90 sets the correction value. Δ can be reduced. When the current temperature (= T) deviates from the assumed temperature T2 after being set or changed from the current assumed temperature (= T1), that is, when T2 <T1 <T is established, the control unit 90 sets the correction value. Δ can be increased. When the current temperature (= T) is between the set or changed assumed temperature T2 and the current assumed temperature (= T1), that is, when T2 <T <T1 is established, the control unit 90 (FIG. The first control unit 90-3 of 3 (B) can decrease the correction value Δ.

  In step ST05 in FIG. 4, the control unit 90 (first control unit 90-3 in FIG. 3B) can determine the correction value as described above. In step ST04, when the difference between the target output intensity and the current output intensity is not greater than or equal to the threshold, the control unit 90 (first control unit 90-3 in FIG. 3B) omits step ST05, in other words. The correction value can be set to zero. In step ST06, the control unit 90 (first control unit 90-3 in FIG. 3B) corrects the control value based on the correction value, and the illumination control unit 91 controls the light source unit 11 with the correction control value. Can be driven. After the illumination control unit 91 drives the light source unit 11 based on the control correction value, the control unit 90 (the first control unit 90-3 in FIG. 3B) detects the current output intensity detected by the detection unit 40. (Step ST07), and the correction value can be adjusted so that the current output intensity matches the target output intensity (step ST09).

  As an example, the illumination control unit 91 can gradually decrease the correction value Δ so that the correction control value d2 ′ in FIG. 5 moves toward the control value d2. Until the current output intensity detected in real time in step ST07 is stabilized at the target output intensity (step ST08), control unit 90 (first control unit 90-3 in FIG. 3B) adjusts the correction value. can do. When the current output intensity is stabilized at the target output intensity, the control unit 90 can update the current output intensity (step ST10). Specifically, the control unit 90 (the first control unit 90-3 in FIG. 3B) can adopt a stable target output intensity as the current output intensity.

  FIG. 6 is an explanatory diagram of a frame F that is a cycle for displaying the display image M of FIG. The frame F includes a display period Fa in which the individual micromirrors of the display element 30 are normally driven and a non-display period Fb in which the non-display period is driven. The ratio of the display period Fa in the frame F is, for example, 50 [%], but is not limited thereto, and may be set to, for example, 70 [%] or 100 [%]. The ratio of the display period Fa in the frame F may be constant or may be determined according to the required luminance. The display period Fa is a period during which the illumination light C from the illumination unit 10 is projected as a display image M toward the screen 60. The non-display period Fb is a period during which the illumination unit 10 is turned off (for example, all the three light emitting diodes 11r, 11g, and 11b are turned off) (see FIGS. 7D to 7F).

  The on-drive period Fap within the display period is a period during which the micromirror is turned on within the display period Fa, and the off-drive period Faq within the display period is a period during which the micromirror is turned off within the display period Fa. The on-drive period Fbp within the non-display period is a period during which the micromirror is turned on within the non-display period Fb, and the off-drive period Fbq within the non-display period is a period during which the micromirror is turned off within the non-display period Fb. In order to prevent the micromirror from sticking when the micromirror is driven, preferably, the sum of the on-drive period Fap within the display period and the on-drive period Fbp within the non-display period (total on-drive period Fp) and the display period The display control unit 92 performs the non-display period on-drive period Fbp and the non-display period so that the sum (the total off-drive period Fq) of the inner off-drive period Faq and the non-display period off-drive period Fbq becomes substantially equal. The in-period off drive period Fbq is adjusted.

  FIG. 7 is an explanatory diagram of a driving method of the display element 30 and the light emitting unit 10 of FIG. As shown in FIGS. 7A to 7C, in the frame F, the display element 30 includes, for example, a single-color mirror Ea that displays green in a single color, a mixed-color mirror Eb that displays a mixed color of red and green, nothing An unlit mirror Ec that is not displayed can be included. As shown in FIG. 7A, the monochromatic mirror Ea is turned on at the lighting timing of the light emitting diode 11g (see FIG. 7E) in the display period Fa based on the display control data D2, and in the non-display period Fb. Is the sum of the ON periods in the frame F, and the display control unit 92 does not display the ON drive period Fbp in the non-display period Fb and the non-display period so that the total ON drive period Fp is approximately half of the frame F. The in-period off drive period Fbq can be adjusted.

  The display control unit 92 turns ON and OFF in the non-display period Fb, the ON drive period Fbp in the non-display period, and the OFF drive period Fbq in the non-display period, like the color mixing mirror Eb shown in FIG. By repeating the cycle according to the above, the total on-drive period Fp and the total off-drive period Fq can be adjusted to be substantially equal. Further, as shown in FIG. 7C, the non-display period drive can be turned on over the non-display period Fb because the extinguishing mirror Ec is off-drive over the display period Fa.

  The present invention is not limited to the above-described exemplary embodiments, and those skilled in the art will be able to easily modify the above-described exemplary embodiments to the extent included in the claims. .

  DESCRIPTION OF SYMBOLS 10 ... Illumination part, 11 ... Light emission part, 11r, 11g, 11b ... Light emitting diode, 20 ... Illumination optical system, 30 ... Display element, 40, 40p, 40t1, 40t2 ... Detection unit, 41 ... sensor, 42 ... A / D converter, 50 ... projection optical system, 60 ... screen, 70 ... flat mirror, 75 ... concave mirror, 80 ... · Housing, 81 ··· Window, 90, 90-1, 90-2, 90-3 ··· Control unit (for example, serial / parallel converter (video signal input unit in a broad sense), micro controller, and Power management IC), 91... Lighting control unit (for example, LED driver), 92... Display control unit (for example, DMD controller), 100... Head-up display device (display device in a broad sense), 200. ..Wind Yield, 250 ... Driver, 300 ... Video signal, CB1, CB2, CB3, CB4 ... Board, D1 ... Lighting control data, D2 ... Display control data, F ... Frame, L ... display light, M ... display image, SF ... sub-frame, V ... virtual image, d1, d2 ... control value, d2 '... correction control value, .DELTA .... correction. value.

Claims (9)

An illumination unit having a light source unit capable of emitting light;
An illumination control unit for controlling the illumination unit;
A display element capable of forming a display image with illumination light from the illumination unit;
A display control unit for controlling the display element;
A first control unit that controls the illumination control unit with illumination control data based on a video signal;
A first substrate on which the display element and the display control unit are mounted;
A second substrate on which the illumination control unit is mounted;
A display device comprising:   The display device according to claim 1, wherein the illumination control unit includes a driver that drives the light source unit.   The display device according to claim 2, wherein the illumination control unit further includes a driver drive power supply unit that supplies a drive power supply for the driver.   The display device according to claim 1, wherein the first control unit is further mounted on the first substrate. A first detection unit for detecting a current output intensity of the light source unit;
In addition,
The first control unit stores a control value corresponding to a target output intensity of the light source unit,
The first control unit determines a correction value for correcting the control value based on a difference between the target output intensity and the current output intensity detected by the first detection unit;
The display device according to claim 1, wherein the illumination control unit drives the light source unit based on a control correction value in which the control value is corrected by the correction value. A second detection unit for detecting a current temperature of the light source unit;
In addition,
6. The first control unit according to claim 1, wherein the first control unit determines the correction value based on the difference between the target output intensity and the current output intensity, and the current temperature. The display device according to any one of the above. The display device according to claim 6, further comprising a third substrate on which the light source unit and the second detection unit are mounted. A second control unit for determining the target output intensity;
In addition,
The display device according to claim 5, wherein the second control unit is further mounted on the second substrate. In the wiring portion between the third substrate and the second substrate, data representing the current temperature flows,
In the wiring part between the first substrate and the second substrate, the data representing the current temperature and the data representing the target output intensity flow,
The second control unit sends the target output intensity and the current temperature to the display control unit,
The display device according to claim 8, wherein the display control unit sends the target output intensity to the first control unit.

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