JP2022022809A - Image plotting device, vehicular lighting fixture, and image plotting method - Google Patents

Abstract

To provide an image plotting device, a vehicular fixture, and an image plotting method, which can suppress a temperature rise of a light source section while miniaturizing the device and reducing power consumption.SOLUTION: An image plotting device (100) includes: a digital mirror device (11) which has a plurality of minute mirrors arrayed on a principal surface and switches angles of the mirrors to the principal surface on the basis of ON information and OFF information included in image data; a light source section (20) which irradiates the plurality of mirrors with light; a temperature acquisition section (12) which measures the temperature of the light source section (20) and acquires a light source section temperature; and an ON-OFF adjustment section (13) which increases the number of pieces of the ON information per unit time included in the image data when the light source section temperature is a first temperature or more.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image drawing device, a vehicle lighting tool, and an image drawing method, and more particularly, an image drawing device, a vehicle lighting tool, and an image drawing method that reflects light and projects an image by a digital mirror device provided with a plurality of minute mirrors. Regarding.

In recent years, with the development of vehicle driving support technology and automatic driving technology, the necessity of transmitting vehicle operation schedules and information to the outside of the vehicle has been discussed. As a method of presenting information to the outside of a vehicle, a method of mounting an image drawing device on a vehicle lamp and drawing an image on a projection surface such as a road surface has been proposed (see, for example, Patent Document 1). In the image drawing device and vehicle lighting equipment described in Patent Document 1, a digital mirror device (DMD: Digital Mirror Device) including a plurality of minute mirrors is used to reflect light to draw an image.

Japanese Unexamined Patent Publication No. 2020-055519

When a light emitting diode (LED: Light Emitting Diode) or a semiconductor laser (LASER: Light Amplification by Standardized Emission of Radiation) is used for the light source of the image drawing device, the light emitting wavelength changes and the luminous efficiency changes when the temperature of the light source changes. Therefore, it is required to control the temperature of the light source unit within a predetermined range.

In order to improve the heat dissipation of the light source unit, it is effective to use a large heat sink, but it becomes difficult to miniaturize the image drawing device. Further, although a cooling fan or a Pelche element can be used as a cooling unit to actively control the temperature of the light source unit, power is consumed to drive the cooling unit, so that an increase in power consumption of the image drawing device becomes a problem.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and is for an image drawing device and a vehicle capable of suppressing a temperature rise of a light source unit while reducing the size of the device and power consumption. It is an object of the present invention to provide a lamp and an image drawing method.

In order to solve the above problems, in the image drawing apparatus of the present invention, a plurality of minute mirrors are arranged on the main surface, and the angle of the mirror with respect to the main surface is determined based on the on information and the off information included in the image data. A digital mirror device to be switched, a light source unit that irradiates the plurality of mirrors with light, a temperature measurement unit that measures the temperature of the light source unit to acquire the temperature of the light source unit, and the light source unit temperature is the first temperature or higher. When the above is the case, it is characterized by including an on / off adjustment unit that increases the number of the on information per unit time included in the image data.

In such an image drawing device of the present invention, when the temperature of the light source unit is the first temperature or higher, the on / off adjustment unit increases the number of on information included in the image data, so that the energy is converted into heat energy inside the device. The amount of light is reduced, and it is possible to suppress the temperature rise of the light source unit while reducing the size of the device and the power consumption.

Further, in one aspect of the present invention, the on / off adjustment unit uses the image data when the number N of the on information and the number M of the off information included in the image data per unit time are N <M. The on-information and the off-information included are all inverted.

Further, in one aspect of the present invention, the on / off adjustment unit increases the on information per unit time for each pixel of the image data.

Further, in one aspect of the present invention, the on / off adjustment unit superimposes a decorative display on the image data.

Further, in one aspect of the present invention, when the temperature of the light source unit is equal to or higher than the second temperature higher than the first temperature, the number of the on information contained in the image data is further increased.

Further, in one aspect of the present invention, a projection optical unit that projects the on-information light reflected by the digital mirror device and a shielding unit that shields the off-information light reflected by the digital mirror device are provided. ..

Further, the vehicle lighting equipment of the present invention is characterized by including the image drawing device according to any one of the above.

Further, the image drawing method of the present invention uses a digital mirror device in which a plurality of minute mirrors are arranged on a main surface, and the angle of the mirror with respect to the main surface is based on on information and off information included in the image data. Switching, irradiating the plurality of mirrors with light from the light source unit, measuring the temperature of the light source unit to acquire the light source unit temperature, and when the light source unit temperature is the first temperature or higher, the image data. It is characterized by increasing the number of the on-information contained in.

INDUSTRIAL APPLICABILITY The present invention can provide an image drawing device, a vehicle lamp, and an image drawing method capable of suppressing an increase in temperature of a light source unit while reducing the size and power consumption of the device.

It is a schematic perspective view which shows the structural example of the image drawing apparatus 100 which concerns on 1st Embodiment. It is a block diagram which shows the image drawing apparatus 100 which concerns on 1st Embodiment. It is a figure which shows typically the image drawing by the on state and the off state of the digital mirror device 11 included in the image projection unit 10. It is a schematic diagram which shows the control of the on information and the off information of the image data in the on / off adjustment unit 13, FIG. 4A shows the state before control, and FIG. 4B shows the state after control. It is a flowchart which shows the control of the on information and the off information of the image data in the on / off adjustment unit 13. It is a schematic diagram which shows the switching of the image data in the on / off adjustment unit 13 which concerns on 3rd Embodiment. It is a schematic diagram which shows the switching of the image data in the on / off adjustment unit 13 which concerns on 4th Embodiment. It is a schematic diagram which shows the switching of the image data in the on / off adjustment unit 13 which concerns on 5th Embodiment.

(First Embodiment)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and duplicate description thereof will be omitted as appropriate. FIG. 1 is a schematic perspective view showing a configuration example of an image drawing apparatus 100 according to the present embodiment. As shown in FIG. 1, the image drawing device 100 includes an image projection unit 10, a light source unit 20, a reflector 30, a projection lens 40, a heat sink 50, and a shielding unit 70, and displays an image on a projection surface 60. Project. The light that is not applied to the projection surface 60 is blocked by the shielding unit 70.

The image projection unit 10 controls the reflection direction of light in the plane based on the on information and the off information included in the information (image data) of the image to be projected, and projects the light emitted from the light source unit 20 into the projected light Lon. It is a device that reflects as a shielding light Loff. The projected light Lon is irradiated to the projection surface 60 via the projection lens 40, and the image is projected by irradiating the region corresponding to the on information with the light. The shielding light Loff reaches the shielding portion 70 and is blocked, and is not irradiated to the outside.

The light source unit 20 is a device that irradiates the reflector 30 with light based on electric power and a signal supplied from the outside, and for example, a light emitting diode or a semiconductor laser can be used. The light emitted from the light source unit 20 may be continuous light (CW: Continuous Wave), pulsed light, or PWM (Pulse Width Modulation) controlled light.

The reflector 30 is an optical member that reflects the light emitted from the light source unit 20 to the image projection unit 10. The shape of the reflective surface of the reflector 30 is not limited, and a curved surface such as a paraboloid or an elliptic curved surface can be used. The light reflected by the reflector 30 may have a light diameter expanded toward the image projection unit 10, or may be parallel light.

The projection lens 40 is an optical member arranged on the optical path of the projected light Lon reflected by the image projection unit 10, and magnifies the projected light Lon and irradiates the projection surface 60 with the projected light Lon. Although FIG. 1 shows an example in which one lens is used as the projection lens 40, a plurality of lenses may be provided. Further, although an example of a convex lens is shown in FIG. 1, a known lens structure such as a concave lens or an aspherical lens can be used. The projection lens 40 corresponds to the projection optical unit in the present invention.

The heat sink 50 is a member on which the light source unit 20 is mounted and arranged to improve heat dissipation. The material constituting the heat sink 50 is not limited, but for example, copper or aluminum having a high thermal conductivity, a highly thermally conductive resin, or the like can be used. Further, the structure and shape of the heat sink 50 are not limited, but if a plurality of fins are erected on the rear surface side, the heat dissipation can be further improved.

The projection surface 60 is provided outside the image drawing device 100, and is a surface on which the projected light Lon is irradiated and an image is projected. Examples of the projection surface 60 include a road surface, a wall surface of a structure, a vehicle body of another vehicle, a vehicle body of a own vehicle, and the like. In FIG. 1, a plane is shown as the projection surface 60, but it may be a surface having a curved surface or unevenness as long as the image can be projected and displayed by being irradiated with the projected light Lon.

The shielding unit 70 is a member for blocking the shielding light Loop that does not contribute to the projection of the image and preventing stray light in the image drawing device 100. The shielding portion 70 is preferably formed in black in order to absorb the shielding light Lof. Further, although the shielding portion 70 is shown as a flat plate in FIG. 1, it is preferable that the shielding portion 70 has a shape so that the incident shielding light Loff does not reach the projection lens 40 direction. Further, the shielding portion 70 may be arranged as an independent member, but a part of a housing or the like constituting the image drawing device 100 may be used.

FIG. 2 is a block diagram showing an image drawing apparatus 100 according to the present embodiment. As shown in FIG. 1, the image drawing device includes an image projection unit 10, a light source unit 20, a reflector 30, a projection lens 40, and a shielding unit 70. Further, the image projection unit 10 includes a digital mirror device 11 and temperature measurement. A unit 12, an on / off adjustment unit 13, and a mirror control unit 14 are provided.

The digital mirror device 11 is an electronic component in which minute mirrors are arranged in a matrix and the tilt angle can be changed between an on state and an off state. Of the mirrors, the projected light Lon reflected in the on state and the shielding light Loff reflected in the off state are separated, and an image is projected by irradiating the projected light Lon.

The temperature measuring unit 12 includes a temperature calculating unit and a thermistor, and although not shown, the thermistor is arranged in the vicinity of the light source unit 20 to measure the temperature of the light source unit 20. The temperature measured by the temperature measuring unit 12 is transmitted to the on / off adjusting unit 13 as the temperature of the light source unit. The specific configuration of the temperature measuring unit 12 is not limited, and a thermistor, a thermocouple, a digital temperature sensor, or the like can be used.

The on / off adjusting unit 13 is a unit that controls the number of on information and off information of the image data based on the temperature of the light source unit measured by the temperature measuring unit 12. The details of the control of the image data by the on / off adjustment unit 13 will be described later. Here, the on / off adjustment unit 13 realizes its function by executing predetermined information processing based on a predetermined program by a control microcomputer (not shown) mounted on the image drawing device 100 or a flash memory. ..

The control microcomputer is an electronic component that controls the drive of the entire image projection unit 10 based on control signals and various measured values. The control microcomputer is capable of information communication with the outside, and image information and control signals are supplied from the outside. Further, the measured value of the temperature measuring unit 12 is transmitted to the control microcomputer. The flash memory is a storage unit for holding information necessary for driving the mirror control unit 14. Examples of the information stored in the flash memory include a program executed by the mirror control unit 14, various setting information, image data, and the like.

When the image data is transmitted from the outside, the control microcomputer transmits the image data to the mirror control unit 14 and controls the on state and the off state of the mirror based on the on information and the off information included in the image data. .. Further, a temperature sensor is mounted in the vicinity of the digital mirror device 11 in addition to the temperature measuring unit 12, and the control microcomputer controls the drive of the cooling unit based on the temperature in the vicinity of the mirror measured by the temperature sensor to digitalize. The temperature of the mirror device 11 is controlled. Here, as the cooling unit, known ones such as a cooling fan, a liquid cooling device, and a Pelche element can be used.

The mirror control unit 14 is an electronic component that transmits a control signal to the digital mirror device 11 based on the on information and the off information included in the image data, and switches and controls the on state and the off state of the mirror. Further, the mirror control unit 14 is connected to a control microcomputer, and the drive is controlled by a control signal from the control microcomputer.

FIG. 3 is a diagram schematically showing image drawing in an on state and an off state of the minute digital mirror device 11 included in the image projection unit 10. Although FIG. 3 shows a state in which the mirror is held flat as an off state, a state in which the mirror is tilted to the opposite side to the on state may be set as an off state. A plurality of minute mirrors are arranged in a matrix on the digital mirror device 11, and the tilt angle of the minute mirrors can be changed between the on state 11on and the off state 11off, and the on information and the off information included in the image can be changed. The tilt angle is controlled accordingly. As a result, the reflection direction of the light in each mirror differs between the on state 11on and the off state 11off, and the projected light Lon reflected in the on state 11on and the shielding light Loff reflected in the off state 11off are separated. In FIG. 3, a matrix arrangement of 20 rows and 20 columns is shown as a minute mirror for simplification, but a high-resolution image can be projected by arranging a larger number of mirrors. Further, the specific structure of the digital mirror device 11 is not limited, and a known structure can be used.

4A and 4B are schematic views showing on / off information control of image data in the on / off adjustment unit 13, FIG. 4A shows a state before control, and FIG. 4B shows a state after control. Shows. In FIG. 4, for simplification of the explanation, a matrix arrangement of 81 dots in 9 rows and 9 columns is shown as image data, but the same applies to image data having a higher resolution.

As shown in FIG. 4A, the image data is digital data in which the on information is included as “1” and the off information is included as “0”. In the example shown in FIG. 4A, the image data for the uppercase alphabet "A" is shown, and the image data includes 23-dot on information and 58-dot off information.

When such image data is transmitted from the control microcomputer to the mirror control unit 14, the mirror control unit 14 controls a minute mirror of the digital mirror device 11 to set the mirror at the position corresponding to the on information to the on state 11on. , The mirror at the position corresponding to the off information is set to the off state 11off. When the light source unit 20 irradiates the image projection unit 10 with light, the light reflected by the mirror in the on state 11on is projected onto the projection surface 60 through the projection lens 40 and irradiates the “A” shape with light. It becomes a drawing. The light reflected by the mirror in the off state 11off is blocked by the shielding portion 70.

At this time, since the energy of the light blocked by the shielding unit 70 is converted into heat energy, the temperature of the image drawing device 100 rises according to the energy of the shielding light Lof. Since an LED or a semiconductor laser is used for the light source unit 20, when the temperature in the vicinity of the light source unit 20 rises, the luminous efficiency decreases and the amount of light at the same current is insufficient. By performing APC (Auto Power Control) control that keeps the amount of light of the light source unit 20 constant, it is possible to prevent a decrease in the amount of light and keep the brightness of the image drawn constant, but the current value required for light emission increases. Then, the temperature rises further.

Therefore, in the image drawing device 100 of the present embodiment, when the temperature of the light source unit measured by the temperature measuring unit 12 is higher than a predetermined temperature (first temperature), the on / off adjusting unit 13 is included in the image data. Controls information and off information, and switches to drawing with image data that suppresses temperature rise. The first temperature is determined by the type and structure of the light source unit 20, the heat dissipation capacity of the heat sink 50, the cooling performance of the cooling unit, and the like, and the specific temperature is not limited, but can be set to, for example, 60 ° C.

Here, the image data that suppresses the temperature information is the image data in which the on-information is increased as compared with the original image data. In the example shown in FIG. 4 (b), the on information "1" and the off information "0" of the image data shown in FIG. 4 (a) are inverted. Therefore, while FIG. 4A includes 23-dot on information and 58-dot off information, FIG. 4B includes 58-dot on information and 23-dot off information. In the switched image data of FIG. 4B, when the light source unit 20 irradiates the image projection unit 10 with light, the quadrangular region is irradiated with light, and the “A” shape is not irradiated with light. Become.

By switching the image data, the shielding light Loop blocked by the shielding portion 70 per unit time is reduced from the amount equivalent to 58 dots to the amount equivalent to 23 dots. Therefore, the heat energy generated in the shielding unit 70 is reduced, and the temperature rise of the image drawing device 100 is suppressed. In the image drawing device 100 of the present embodiment, it is possible to suppress the temperature rise of the light source unit only by switching the image data without increasing the size of the heat sink 50 and the power required for forced heat dissipation in the cooling unit. Is.

FIG. 5 is a flowchart showing on / off information control of image data in the on / off adjustment unit 13. First, in the temperature determination step of step S1, the on / off adjusting unit 13 acquires the temperature of the light source unit measured by the temperature measuring unit 12, and determines whether or not the temperature in the vicinity of the light source unit 20 is equal to or higher than the predetermined temperature. In the present embodiment, when the temperature of the light source unit is equal to or higher than the first temperature, the process proceeds to step S2, and when the temperature is lower than the first temperature, the process proceeds to step S5.

In the on / off comparison step of step S2, the on / off adjusting unit 13 compares the number M of the off information contained in the image data with the number N of the on information, and if N <M, the process proceeds to step S3, and N ≧ M. In the case of, the process proceeds to step S5. Here, the number M of the off information and the number N of the on information are the numbers of "0" and "1" when the image data is binary data. Further, when the image data is gradation data weighted in time by PWM control or the like, the time integration of "0" and "1" included in the unit time is obtained.

In the image change possibility determination step of step S3, the on / off adjustment unit 13 determines whether or not the image data can be changed, and if the image data is permitted to change the image, the process proceeds to step S4, and the image change is performed. In the case of image data that is not permitted, the process proceeds to step S5. As a method of determining whether or not an image can be changed, for example, change permission information that permits image change is added to the image data, and if there is change permission information, it can be changed, and if there is no change permission information, it can be changed. It can be said that it cannot be changed.

In the image switching step of step S4, the on / off adjustment unit 13 generates new image data in which the on information and the off information of the image data are inverted, and inverts the on state 11on and the off state 11off in the digital mirror device 11. Draw. When the switching drawing of the image data is completed, the process proceeds to step S6. Here, when the image data is binary data, the image data that can be switched is as shown in FIGS. 4A and 4B. Even when the image data is time-weighted gradation data by PWM control or the like, by inverting the entire weighted gradation data, the number M of off information and the on information included per unit time can be obtained. The number N can be inverted.

In the image maintenance step of step S5, the on / off adjustment unit 13 does not switch the image data, and the drawing is performed while the on information and the off information of the image data are maintained. When the drawing with the image data is completed, the process proceeds to step S6.

In the image update step of step S6, the control microcomputer reads the image data to be drawn next, updates the image data, and proceeds to step S1. Here, the image data is updated, but when the image to be drawn is a still image, the updated image data is the same as the previous time, and is the image data before being switched in the image switching step of step S4. When the image to be drawn is a moving image, the updated image data becomes a new image after the lapse of time in the moving image.

As described above, in the image drawing device 100 and the image drawing method of the present embodiment, the temperature of the light source unit 20 is measured by the temperature measuring unit 12 to acquire the temperature of the light source unit, and the temperature of the light source unit is equal to or higher than the first temperature. In this case, the on / off adjustment unit 13 increases the number of on information per unit time included in the image data. As a result, the amount of light blocked by the shielding unit 70 is reduced, the light energy converted into heat energy in the image drawing device 100 is reduced, and the temperature rise can be easily suppressed.

Further, the on / off adjustment unit 13 inverts all the on information and the off information included in the image data when the number N of the on information and the number M of the off information included in the image data per unit time are N <M. As a result, the temperature rise can be suppressed by simple information processing of inversion of on information and off information.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The description of the contents overlapping with the first embodiment will be omitted. In the image drawing device 100 and the image drawing method of the present embodiment, the case where the image data is not binary data but gradation data is shown. In the first embodiment, the on information and the off information included in the image data are inverted, but in the present embodiment, the on information per unit time is increased for each pixel in the gradation expression of the image data. ..

When the image data is gradation data, as an example, the pulse width included in one unit time is divided into 1, 2, 4, 8, 16, 32, 64, 128, etc., and 256 gradations are integrated by time integration. Expresses the gradation of. Such gradation expression is performed in each pixel (dot) included in the image data. When all the pulse widths are off information "0", the gradation is 0 and represents re-low brightness, and when all pulse widths are on information "1", the gradation is 255 and represents the maximum brightness. When the pulse width is only 128 and the on information is "1", the gradation is 128, which represents the intermediate brightness.

Even in the image drawing with the gradation data described above, the minute mirror of the digital mirror device 11 is turned on in the on state 11on when the on information is “1”, and is turned off in the off state when the off information is “0”. Further, the shielded light Loff reflected by the mirror in the off state 11off is blocked by the shielding portion 70 and converted into thermal energy. Therefore, for all the pixels included in the image data, the sum of the off information "0" per unit time becomes heat energy and causes a temperature rise. That is, the more the drawing is performed on the image having low brightness, the more easily the temperature of the image drawing device 100 rises.

Therefore, in the present embodiment, the on / off adjustment unit 13 increases the on information “1” so as to increase the brightness in each pixel of the image data. That is, it is possible to raise the gradation of all the pixels of the image data to uniformly increase the brightness. For example, when the gradation of all the pixels is increased by 8, the gradation 0 becomes the gradation 8 and the gradation 100 becomes the gradation 108. However, since the maximum luminance is predetermined, the upper limit is the maximum luminance, for example, a pixel having a luminance higher than the gradation 247 has a gradation 255.

In the present embodiment, the on / off comparison step of step S2 is not executed in the flowchart shown in FIG. 5, and the process shifts to the image changeability determination step of step S3. In the image change possibility determination step of step S3, it is determined whether or not the change of the image data is permitted as in the first embodiment, and if the change is possible, the process proceeds to step S4, and if the change is not possible, the step Move to S5.

In the image switching step of step S4, as described above, drawing is performed by increasing the on information "1" included in the image data so as to uniformly improve the brightness in each pixel of the image data. When the switching drawing of the image data is completed, the process proceeds to step S6.

As described above, also in the image drawing device 100 and the image drawing method of the present embodiment, the temperature of the light source unit 20 is measured by the temperature measuring unit 12 to acquire the temperature of the light source unit, and the temperature of the light source unit is equal to or higher than the first temperature. In addition, the on / off adjustment unit 13 increases the number of on information per unit time included in the image data. As a result, the amount of light blocked by the shielding unit 70 is reduced, the light energy converted into heat energy in the image drawing device 100 is reduced, and the temperature rise can be easily suppressed.

(Modification example)
Next, a modified example of this embodiment will be described. In the above-mentioned example, the brightness is improved when the temperature of the light source unit measured by the temperature measuring unit 12 is the first temperature or higher, but even if the degree of the brightness improvement is increased according to the temperature of the light source unit. good.

In this modification, a plurality of threshold values such as a first temperature, a second temperature, and a third temperature are set in advance as the temperature. The second temperature is higher than the first temperature, and the third temperature is higher than the second temperature. In the temperature determination step of step S1, the on / off adjusting unit 13 acquires the temperature of the light source unit measured by the temperature measuring unit 12, and the temperature in the vicinity of the light source unit 20 is less than the first temperature, the first temperature or more and less than the second temperature, and the second. It is determined whether the temperature is in the range of the temperature or more and less than the third temperature or the third temperature or more. When the temperature of the light source unit is lower than the first temperature, the process proceeds to step S5, and when the temperature is in the other range, a predetermined brightness change amount according to the temperature range is acquired and the process proceeds to step S2.

For example, when the temperature of the light source unit is the first temperature or more and less than the second temperature, the brightness change amount is 5, and when the second temperature or more and less than the third temperature, the brightness change amount is 10, and when the temperature is the third temperature or more. The brightness change amount is set to 20.

Step S2 and step S3 are the same as the above-mentioned example. In the image switching step of step S4, drawing is performed by increasing the on information "1" included in the image data so as to improve the brightness in each pixel of the image data by the amount of the brightness change acquired in step S1. When the switching drawing of the image data is completed, the process proceeds to step S6.

In this modification, when the temperature of the light source unit is equal to or higher than the second temperature higher than the first temperature, the number of on information included in the image data is further increased. As a result, as the temperature of the light source unit 20 increases, the number of off information of the image data decreases, the shielding light Lof that becomes heat energy in the shielding unit 70 can be reduced, and the temperature rise can be further suppressed.

(Third Embodiment)
Next, the third embodiment of the present invention will be described with reference to FIG. The description of the contents overlapping with the first embodiment will be omitted. FIG. 6 is a schematic diagram showing switching of image data in the on / off adjustment unit 13 according to the present embodiment. The left side of FIG. 6 is the image data before the change drawn when the temperature of the light source unit is lower than the first temperature, and the right side of FIG. 6 is the image after the change drawn when the temperature of the light source unit is the first temperature or higher. It is data.

In the example shown in FIG. 6, the image data before the change is displayed in a normal font, and the image data after the change is decorated with "bold" and the width of the character constituent is widened. .. In this way, by superimposing the decorative display on the original image data, it is possible to increase the number of on information per unit time included in the image data.

In FIG. 6, "bold" is shown as a decorative display to be superimposed on the image data, but the type of the decorative display is not limited as long as it increases the on-information per unit time included in the image data. Other decorative displays on which image data are superimposed include adding a background image, enlarging the character size, adding an underline, adding a frame, and the like.

In the present embodiment, in the image switching step of step S4, the on / off adjustment unit 13 superimposes the decorative display on the original image data to generate new image data and perform drawing. When the switching drawing of the image data is completed, the process proceeds to step S6. Other steps are the same as in the second embodiment.

As described above, also in the image drawing device 100 and the image drawing method of the present embodiment, the temperature of the light source unit 20 is measured by the temperature measuring unit 12 to acquire the temperature of the light source unit, and the temperature of the light source unit is equal to or higher than the first temperature. In addition, the on / off adjustment unit 13 increases the number of on information per unit time included in the image data. As a result, the amount of light blocked by the shielding unit 70 is reduced, the light energy converted into heat energy in the image drawing device 100 is reduced, and the temperature rise can be easily suppressed.

Further, since the decorative display prepared in advance is superimposed on the original image data to generate new image data, the image processing in the on / off adjustment unit 13 becomes simple, and the visibility after switching the image data is also decorated. It can be predicted from the contents of the display, and the design can be improved.

(Fourth Embodiment)
Next, the fourth embodiment of the present invention will be described with reference to FIG. 7. The description of the contents overlapping with the first embodiment will be omitted. FIG. 7 is a schematic diagram showing switching of image data in the on / off adjustment unit 13 according to the present embodiment. The left side of FIG. 7 is the image data before the change drawn when the temperature of the light source unit is lower than the first temperature, and the right side of FIG. 7 is the image after the change drawn when the temperature of the light source unit is the first temperature or higher. It is data.

In the example shown in FIG. 7, the image data before the change is a graphic, and the image data after the change selectively inverts a predetermined area. In this way, by selecting and inverting a part of the area in the original image data, it is possible to increase the number of on-information contained in the image data per unit time. In the example shown in FIG. 7, a circle is shown as the selected inversion region, but any graphic region such as a rectangular shape, a polygonal shape, or a strip shape can be selected. Further, an area including the entire figure of the original image data may be selected, or an area including a part of the figure of the original image data may be selected.

In the present embodiment, in the image switching step of step S4, the on / off adjustment unit 13 selects a predetermined region of the image data, and new image data in which the on information and the off information are inverted in the region. Is generated and drawn. When the switching drawing of the image data is completed, the process proceeds to step S6. Other steps are the same as in the first embodiment.

As described above, also in the image drawing device 100 and the image drawing method of the present embodiment, the temperature of the light source unit 20 is measured by the temperature measuring unit 12 to acquire the temperature of the light source unit, and the temperature of the light source unit is equal to or higher than the first temperature. In addition, the on / off adjustment unit 13 increases the number of on information per unit time included in the image data. As a result, the amount of light blocked by the shielding unit 70 is reduced, the light energy converted into heat energy in the image drawing device 100 is reduced, and the temperature rise can be easily suppressed.

Further, since the original image data is inverted by selecting a predetermined selection area, the image processing in the on / off adjustment unit 13 becomes simple, and the design can be improved even after the image data is switched. ..

(Fifth Embodiment)
Next, the fifth embodiment of the present invention will be described with reference to FIG. The description of the contents overlapping with the second embodiment will be omitted. FIG. 8 is a schematic diagram showing switching of image data in the on / off adjustment unit 13 according to the present embodiment. In the present embodiment, the image data is gradation data, and the difference from the second embodiment is that the brightness is changed stepwise.

The figure shown in FIG. 8A is a drawing based on the original image data, and the brightness in the image data is expressed by the shading in the figure. The darker the black color in the figure, the higher the brightness in the image data, and the lighter the black color, the lower the brightness.

In the present embodiment, as shown in FIGS. 8 (a) to 8 (f), the on / off adjusting unit 13 gradually increases the brightness of the image data and reaches the maximum brightness of FIG. 8 (f). Later, the original image data is returned to FIG. 8A. By executing the change to increase the brightness of the image data stepwise and periodically in this way, the number of on-information contained in the image data per unit time is increased.

In the present embodiment, the on / off comparison step of step S2 is not executed in the flowchart shown in FIG. 5, and the process shifts to the image changeability determination step of step S3. In the image change possibility determination step of step S3, it is determined whether or not the change of the image data is permitted as in the first embodiment, and if the change is possible, the process proceeds to step S4, and if the change is not possible, the step Move to S5.

In the image switching step of step S4, as described above, drawing is performed by increasing the on information "1" included in the image data so as to uniformly improve the brightness in each pixel of the image data. At this time, the luminance is divided into a plurality of stages from the low luminance FIG. 8 (a) to the high luminance FIG. 8 (f), and the stage is updated when the condition is satisfied in step S4. Specifically, when the first step S4 is executed, the image data is switched to FIG. 8A, the image data, the image number, and the image switching time are recorded in a flash memory or the like, and the process proceeds to step S6.

In the second and subsequent steps S4, if a predetermined time has not elapsed from the image switching time, the process proceeds to step S6 without updating the image data, the image number, and the image switching time. If a predetermined time has passed from the image switching time, the image data is switched to the next stage of the recorded image number, and the image data, the image number, and the image switching time recorded in the flash memory or the like are updated. , The process proceeds to step S6. After the switching drawing of the image data up to FIG. 8 (f) is completed, the image data and the image number are updated again in FIG. 8 (a). Other steps are the same as in the second embodiment.

As described above, also in the image drawing device 100 and the image drawing method of the present embodiment, the temperature of the light source unit 20 is measured by the temperature measuring unit 12 to acquire the temperature of the light source unit, and the temperature of the light source unit is equal to or higher than the first temperature. In addition, the on / off adjustment unit 13 increases the number of on information per unit time included in the image data. As a result, the amount of light blocked by the shielding unit 70 is reduced, the light energy converted into heat energy in the image drawing device 100 is reduced, and the temperature rise can be easily suppressed.

Further, by gradually and periodically improving the brightness, drawing with many low-luminance areas as shown in FIGS. 8 (a) and 8 (b) and drawing with many low-luminance areas and FIGS. 8 (e) and 8 (f) are performed. Drawing with many high-brightness areas is repeatedly executed. As a result, in drawing with many low-luminance areas, it is possible to maintain the contrast of the figure to be drawn and improve the visibility.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

100 ... Image drawing device 10 ... Image projection unit 20 ... Light source unit 30 ... Reflector 40 ... Projection lens 50 ... Heat sink 60 ... Projection surface 70 ... Shielding unit 11 ... Digital mirror device 12 ... Temperature measurement unit 13 ... On / off adjustment unit 14 ... Mirror Control unit

Claims (8)

A digital mirror device in which a plurality of minute mirrors are arranged on the main surface and the angle of the mirror with respect to the main surface is switched based on the on information and the off information contained in the image data.
A light source unit that irradiates the plurality of mirrors with light,
A temperature measuring unit that measures the temperature of the light source unit and acquires the temperature of the light source unit,
An image drawing apparatus comprising an on / off adjusting unit that increases the number of on information per unit time included in the image data when the temperature of the light source unit is equal to or higher than the first temperature. The image drawing apparatus according to claim 1.
When the number N of the on information and the number M of the off information per unit time included in the image data are N <M, the on / off adjustment unit includes the on information and the off information included in the image data. An image drawing device characterized by inverting all of the above. The image drawing apparatus according to claim 1.
The on / off adjustment unit is an image drawing device characterized by increasing the on information per unit time for each pixel of the image data. The image drawing apparatus according to claim 1.
The on / off adjustment unit is an image drawing device characterized by superimposing a decorative display on the image data. The image drawing apparatus according to claim 3 or 4.
An image drawing apparatus, characterized in that the number of on information included in the image data is further increased when the temperature of the light source unit is equal to or higher than the second temperature higher than the first temperature. The image drawing apparatus according to any one of claims 1 to 5.
A projection optical unit that projects the on-information light reflected by the digital mirror device, and
An image drawing device comprising a shielding unit that shields the light of the off information reflected by the digital mirror device. A vehicle lamp comprising the image drawing apparatus according to any one of claims 1 to 6. Using a digital mirror device in which a plurality of minute mirrors are arranged on the main surface, the angle of the mirror with respect to the main surface is switched based on the on information and the off information included in the image data.
Light is emitted from the light source unit to the plurality of mirrors,
The temperature of the light source unit is measured to obtain the temperature of the light source unit.
An image drawing method characterized in that the number of on information included in the image data is increased when the temperature of the light source unit is equal to or higher than the first temperature.

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