JP2018017752A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device that can both prevent a person who views an image from being made to feel incompatible and correct drive conditions of a light source.SOLUTION: A projection type display device 10 comprises a light source part 20, a control part 30 which drives the light source part 20 based upon control data, a spatial light modulation part 40, and an emission quantity acquisition part 50 which acquires an emission quantity of light that the light source part 20 emits. When the projection display device 10 is actuated, the control part 30 drives the light source part 20 so that the emission quantity of the light that the light source part 20 emits gradually varies from a first target emission quantity to a second target emission quantity. The control part 30 switches the control data to control data having been corrected while or before or after the emission quantity of the light that the light source part 20 emits gradually varies so that the difference between the emission quantity that the emission quantity acquisition part 50 acquires and the target emission quantity at the point of time when the emission quantity is acquired becomes small.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a projection display device. The present invention particularly relates to a projection display apparatus that emits light from a light source with a desired radiation amount.

  As a type of display device, a projection display device that displays an image by projecting a generated image onto an arbitrary screen or the like is known. The projection display device projects, for example, three-color light of red, green, and blue corresponding to the three primary colors of light by spatial light modulation using a light modulation element such as a liquid crystal device or DMD (Digital Micromirror Device). Form an image.

  This three-color light can be obtained by separating white light emitted from one light source or using three light sources that emit light of each color. In recent years, the use of semiconductor light emitting elements such as LEDs (Light Emitting Diodes) and semiconductor lasers as light sources has been put into practical use. Since the semiconductor light emitting element emits different colors depending on the material, each color corresponding to the three primary colors of light can be obtained by selecting an appropriate material.

  As a light source for a projection display device, for example, when a semiconductor light emitting element that emits red light, a semiconductor light emitting element that emits green light, and a semiconductor light emitting element that emits blue light are used, the light emitted from the three light sources is mixed. In order to obtain white light, it is necessary to adjust the balance of the amount of light emitted from each light source (white balance). Each light source emits light with the white balance adjusted, whereby a high-quality full-color image can be obtained.

  Here, since the materials of the semiconductor light emitting elements used for the three light sources are different, for example, the degree of deterioration over time, the degree of influence of the external temperature during use, and the like differ depending on each light source. As a result, even when the white balance of the three light sources is optimally adjusted at the time of shipment of the projection display device from the factory, the optimal white balance can be obtained depending on the long-term use and the external environment during use. It may be difficult to maintain, and a situation such as being unable to obtain a high-quality full-color image may occur.

  In order to eliminate the occurrence of such a situation, for example, a projection display device disclosed in Patent Document 1 has been proposed. The projection display device disclosed in Patent Document 1 includes a light receiving element to acquire the light amount of light emitted by the three light sources for each light source, and increase or decrease the light amount of each light source based on the acquired light amounts. The driving conditions such as the output of each light source are corrected so that the In the projection display device disclosed in Patent Document 1, the desired white balance is maintained by correcting the driving conditions of each light source so that the light amounts of the three light sources acquired by the light receiving element have the desired white balance. can do.

  By the way, Patent Document 1 does not mention the timing for performing the correction of the driving conditions of the three light sources. For example, in the projection display device disclosed in Patent Document 1, the hue, brightness, and the like of an image are corrected by correcting at least one driving condition of three light sources while a person is viewing a displayed image. The present inventors have recognized that there is a possibility of giving a strange feeling to a person who is looking at the image because of the change.

JP 2007-65012 A

  One object of the present invention is to provide a projection display device capable of reducing both the uncomfortable feeling given to a person viewing an image and correcting the driving conditions of the light source. Other objects of the present invention will become apparent to those skilled in the art by referring to the aspects and preferred embodiments exemplified below and the accompanying drawings.

A first aspect according to the present invention includes a light source unit,
A control unit that drives the light source unit based on control data indicating a correspondence relationship between a target radiation amount of the light source unit and a driving condition of the light source unit;
A spatial light modulator that spatially modulates light emitted from the light source unit under the control of the controller to form an image;
A radiation amount acquisition unit for acquiring a radiation amount of the light emitted by the light source unit;
With
When the projection display device is activated, the control unit controls the spatial light modulation unit so that a first image is formed, and the radiation amount of the light emitted from the light source unit is first. After the light source unit is driven so that the target radiation amount is equal to the second target radiation amount, the radiation amount of the light emitted by the light source unit is different from the first target radiation amount from the first target radiation amount. Execute the start-up expression, driving the light source unit to gradually change to the target radiation amount of
The control unit reduces a difference between the radiation amount acquired by the radiation amount acquisition unit while executing the startup expression and the target radiation amount at the time when the radiation amount is acquired. A correction value for correcting the control data is determined, and the control data is corrected by the correction value while the radiation amount of the light emitted by the light source unit gradually changes or before and after the change. The present invention relates to a projection display device that switches to control data after correction.

  In the projection display device according to the first aspect, the control unit switches the control data from the pre-correction control data to the post-correction control data while the emission amount of the light emitted from the light source unit gradually changes or before and after the change. This suppresses a noticeable change in the image (virtual image) caused by switching the control data. Therefore, for example, compared to switching control data while displaying an image (virtual image) in which the brightness of the image (virtual image) does not change, the uncomfortable feeling given to a person viewing the image (virtual image) is reduced. can do.

In the 2nd mode according to the present invention, in the 1st mode, it further has an external illumination intensity information acquisition part which acquires external illumination intensity information,
The target radiation amount of the light source unit after the start time expression is completed is associated with the external illuminance information acquired by the external illuminance information acquisition unit,
The control unit determines the first target radiation amount and the second target radiation amount according to the external illuminance information acquired by the external illuminance information acquisition unit when or before executing the startup expression. You may decide.

  The target radiation amount of the light source unit in the normal time expression after the start time expression is finished is determined according to the external illuminance information acquired by the external illuminance information acquiring unit. When the start time expression ends and the normal time expression is executed by determining the first target radiation amount and the second target radiation amount according to the external illumination information acquired by the external illumination information acquisition unit In addition, it is possible to suppress a significant change in the brightness of the image (virtual image).

In a third aspect according to the present invention, in the second aspect, the start time expression associated with the external illuminance information acquired by the external illuminance information acquisition unit when or before the start time expression is executed. When the target radiation amount of the light source unit after is finished is larger than the first target radiation amount,
While the control unit determines the second target radiation amount to be larger than the first target radiation amount,
The target radiation amount of the light source unit after completion of the start-up expression, which is associated with the external illuminance information acquired by the external illuminance information acquisition unit when or before executing the start-up expression, When smaller than the first target radiation amount,
The control unit may determine the second target radiation amount to be smaller than the first target radiation amount.

  In the third aspect, the control unit can subdivide and determine the second target radiation amount in the startup expression according to the external illumination information acquired by the external illumination information acquisition unit. It is possible to further suppress the brightness of the image (virtual image) from changing greatly when the normal time expression is executed after completion.

  In a fourth aspect according to the present invention, in the second aspect, the control unit is associated with the external illuminance information acquired by the external illuminance information acquisition unit when or before executing the startup expression. The second target radiation amount may be determined such that the target radiation amount of the light source unit after the start-up expression is matched with the second target radiation amount.

  In the fourth aspect, the control unit determines the second target radiation amount in the start time expression so that the third target radiation amount in the normal time expression matches the second target radiation amount in the start time expression. Thus, when the start time expression ends and the normal time expression is executed, the brightness of the image (virtual image) can be further prevented from changing greatly.

In a fifth aspect according to the present invention, in any one of the first to fourth aspects, the control unit starts the execution of the startup expression within an arbitrary period after the startup expression ends.
The spatial light modulation unit may be controlled so that an image to be formed gradually changes from the first image to a second image different from the first image.

  In the fifth aspect, in addition to a gradual change in the amount of light emitted from the light source unit, a displayed image (virtual image) also changes gradually, thereby causing an image ( The conspicuous change in the virtual image is further suppressed.

  In a sixth aspect according to the present invention, in the first to fifth aspects, the control unit is configured to control the control data before or after the radiation amount of the light emitted by the light source unit gradually changes. May be gradually switched to post-correction control data corrected by the correction value.

  In the sixth aspect, when the control data is gradually switched from the pre-correction control data to the post-correction control data, for example, there is a change in the image (virtual image) caused by switching the control data as compared with the case of switching instantaneously. Conspicuousness is suppressed.

  In a seventh aspect according to the present invention, in the first to fifth aspects, the control unit controls the control data before or after the radiation amount of the light emitted by the light source unit gradually changes. May be instantaneously switched to post-correction control data corrected by the correction value.

  In the seventh aspect, when the control data is instantaneously switched from the pre-correction control data to the post-correction control data, for example, the calculation of the driving condition of the light source unit during the switching of the control data compared to the case where the control data is gradually switched, etc. The processing burden on the control unit is reduced.

In an eighth aspect according to the present invention, in the first to seventh aspects, the light source unit includes a red light emitting element, a green light emitting element, and a blue light emitting element,
The control data includes red light emitting element control data, green light emitting element control data, and blue light emitting element control data,
The control data for the red light emitting element, the control data for the green light emitting element, and the control data for the blue light emitting element are obtained by mixing the light emitted by the red light emitting element, the green light emitting element, and the blue light emitting element. Shows the correspondence between the target radiation amount of each light emitting element such that white light can be obtained and the driving conditions of each light emitting element,
The correction value may be determined individually for red light emitting element control data, green light emitting element control data, and blue light emitting element control data.

  A high-quality full-color image can be displayed on the projection display device.

It is a block diagram which shows the example of a structure of the projection type display apparatus of this invention. It is a figure which shows the example of the control data which the control part shown by FIG. 1 has. FIG. 3 is a diagram illustrating an example of control data before correction and control data after correction in the control data shown in FIG. 2. In the example shown by FIG. 3, it is a figure which shows the example which makes the 2nd target radiation amount of the light source part in start time expression larger than the 1st target radiation amount of a light source part. In the example shown by FIG. 3, it is a figure which shows the example which makes the 2nd target radiation amount of the light source part in start time expression smaller than the 1st target radiation amount of a light source part. It is a figure which shows the example which determines the 1st target radiation amount and the 2nd target radiation amount in start time expression according to the 3rd target radiation amount in normal time expression. In the example shown in FIG. 5, it is a figure which shows the example which makes the 2nd target radiation amount of the light source part in start time expression larger than the 1st target radiation amount of a light source part. In the example shown in FIG. 5, it is a figure which shows the example which makes the 2nd target radiation amount of the light source part in start time expression smaller than the 1st target radiation amount of a light source part. In the example shown in FIG. 3, it is a figure which shows the example which makes the 2nd target radiation amount of the light source part in start time expression correspond with the 3rd target radiation amount of the light source part in normal time expression. In the example shown in FIG. 5, it is a figure which shows the example which makes the 2nd target radiation amount of the light source part in start time expression correspond with the 3rd target radiation amount of the light source part in normal time expression. It is a figure which shows an example from which the image (virtual image) displayed changes gradually from a 1st image to a 2nd image.

  The preferred embodiments described below are used to facilitate an understanding of the present invention. Accordingly, those skilled in the art should note that the present invention is not unduly limited by the embodiments described below.

<< 1. Overall configuration >>
An example of the overall configuration of the projection display apparatus 10 of the present invention will be described. FIG. 1 shows a projection display device (head-up display device) 10 mounted on a vehicle 100 as an example of the projection display device 10. 1 represents the front viewed from the driver of the vehicle 100, and Rr illustrated in FIG. 1 represents the rear viewed from the driver of the vehicle 100.

  The driver of the vehicle 100 causes the light 80 constituting the image formed by the projection display device 10 to be reflected by the front window shield 110 and enter the position of the driver's viewpoint. The virtual image 200 can be visually recognized. For example, the driver of the vehicle 100 can visually recognize the virtual image 200 in a state where at least a part of the scenery seen through the front window shield 110 and the virtual image 200 are superimposed.

  The projection display device 10 includes a light source unit 20, a control unit 30, a spatial light modulation unit 40, and a radiation amount acquisition unit 50. The projection display apparatus 10 may further include, for example, an external illuminance information acquisition unit 60, a light source unit drive circuit unit 71, and an integration circuit unit 72.

  The light source unit 20 includes a light emitting element such as an LED (Light Emitting Diode) that emits light when a drive current is supplied from the light source unit drive circuit unit 71. The light source unit 20 includes, for example, a red LED 21, a green LED 22, and a blue LED 23 corresponding to the three primary colors of light in order to obtain white light so that a color image can be formed as the projection display device 10. When the light source unit 20 includes three LEDs, the light source unit drive circuit unit 71 may include three drive circuits so that a drive current can be individually supplied to the three LEDs. In the present embodiment, an example in which the red LED 21, the green LED 22, and the blue LED 23 are employed as the light emitting elements of the light source unit 20 will be described. However, the light emitting element of the light source unit 20 is, for example, another semiconductor light emitting element such as a semiconductor laser. It may be.

  The control unit 30 is a microcomputer responsible for overall control of the projection display device 10, and includes a processing unit 31, a storage unit 32, and an input / output unit 33. The processing unit 31 includes, for example, one or a plurality of microprocessors, a microcontroller, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), and any other IC (Integrated Circuit). The storage unit 32 is, for example, a rewritable RAM (Random Access Memory), a read-only ROM (Read Only Memory), an erasable program read-only EEPROM (Electrically Erasable Programmable Read-Only Memory), or a nonvolatile memory. It has one or a plurality of memories capable of storing programs and / or data such as a flash memory. The input / output unit 33 is an input / output port directly connected to the spatial light modulation unit 40, the external illuminance information acquisition unit 60, the light source unit drive circuit unit 71, the integration circuit unit 72, or other devices not shown. A communication unit connected to a communication line of a network such as a CAN (Controller Area Network).

  For example, the control unit 30 implements control of the entire projection display apparatus 10 by causing the processing unit 31 to execute a program stored in the storage unit 32. The storage unit 32 stores control data indicating the correspondence between the target radiation amount of the light source unit 20 and the driving conditions of the light source unit 20, and the processing unit 31 drives the light source unit 20 based on the control data. Let

  The spatial light modulator 40 includes, for example, a DMD (Digital Micromirror Device), and forms an image by spatially modulating light emitted from the light source 20 under the control of the controller 30. The DMD includes a plurality of micromirrors, and each micromirror can individually shift the tilt state between at least two tilt states under the control of the control unit 30. The first tilt state, which is one of the two tilt states of the micromirror, is a tilt state in which light incident from the light source unit 20 is reflected as the light 80 constituting the image, and the other of the two tilt states of the micromirror. The second tilted state is a tilted state in which the light incident from the light source unit 20 is not reflected as the light 80 constituting the image. Each micromirror corresponds to one pixel of the displayed image. That is, the DMD can control whether or not the light incident from the light source unit 20 is reflected as light 80 constituting the image for each pixel of the image. In the present embodiment, an example in which DMD is employed as the spatial light modulator 40 will be described. However, the spatial light modulator 40 may be another spatial light modulator such as a liquid crystal device, for example.

  The radiation amount acquisition unit 50 is configured to be able to acquire the radiation amount of light emitted from the light source unit 20, and for example, a light receiving element such as a photodiode, a photo IC diode, or a phototransistor that outputs a current according to the light radiation amount. Have. The radiation amount acquisition unit 50 is preferably provided with three light receiving elements so as to correspond to the three-color light emitted by the three LEDs of the light source unit 20.

  The external illuminance information acquisition unit 60 is configured to be able to acquire external illuminance information that is information related to illuminance outside the projection display device 10. In the example shown in FIG. 1, the external illuminance information acquisition unit 60 is an illuminance sensor having a light receiving element such as a photodiode, a photo IC diode, or a phototransistor attached to the inside of the front window shield 110. The external illuminance information acquisition unit 60 may be an external illuminance information acquisition unit 60 dedicated to the projection display device 10 that is directly connected to the control unit 30 as shown in FIG. 1, and is directly or illustrated with the control unit 30. The shared external illuminance information acquisition unit 60 may also be used for other purposes connected to the control unit 30 via a communication line of a network that is not connected. Other applications include, for example, an autolight system that automatically turns on a headlight according to the brightness outside the vehicle. The external illuminance information acquisition unit 60 may be realized by the processing unit 31 of the control unit 30 executing a program stored in the storage unit 32. In this case, the control unit 30 that functions as the external illuminance information acquisition unit 60 may acquire external illuminance information according to a current value input from a light receiving element or the like attached to the outside of the projection display device 10.

  For example, the light source unit drive circuit unit 71 is configured to supply a drive current corresponding to a PWM (Pulse Width Modulation) signal received from the control unit 30 to the light source unit 20. The integrating circuit unit 72 is configured to integrate the radiation amount of light detected by the radiation amount acquisition unit 50 with time. For example, the integration circuit unit 72 integrates the current value input from the radiation amount acquisition unit 50 or the voltage value converted by using an IV conversion circuit (not shown) with time by the integration circuit, thereby calculating the light emission amount. Integrate over time. When the radiation amount acquisition unit 50 includes three light receiving elements, the integration circuit unit 72 includes three integration circuits so as to correspond to the respective light receiving elements.

  Further, the projection display device 10 is illustrated in such a manner that the light 80 constituting the image formed by the light emitted from the light source unit 20 being spatially light modulated by the spatial light modulator 40 is guided to the front window shield 110. A case 76 including an optical system composed of lenses, mirrors, and the like that are not included is further provided. The case 76 preferably includes at least the light source unit 20, the spatial light modulation unit 40, and the radiation amount acquisition unit 50 inside, and may further include the control unit 30, the light source unit drive circuit unit 71, and the integration circuit unit 72 therein. Good.

<< 2. Basic operation >>
The basic operation of the projection display apparatus 10 will be described. The control unit 30 creates an image for each preset period (frame) for displaying the image. The image generated by the control unit 30 is generated so as to include the current vehicle speed input from a vehicle speed sensor (not shown) via a network communication line (not shown), for example. The projection display device 10 displays an image generated by the control unit 30 by an FSC (Field Sequential Color) method for each frame.

  An image display by the FSC method will be briefly described. One frame period is composed of a plurality of subframes. The control unit 30 outputs a PWM signal to each drive circuit of the light source unit drive circuit unit 71 so that the three colors of LEDs of the light source unit 20 emit light one color at each subframe. Note that one frame period is configured by the number of subframes corresponding to the number of gradations of each color. For example, when the number of gradations of each color is 256, it is configured by 8 colors for a total of 24 subframes. .

  The control unit 30 controls the plurality of DMD micromirrors of the spatial light modulation unit 40 to be in the first tilt state or the second tilt state for each subframe. That is, the control unit 30 individually controls the gradation of each color and all the pixels of the displayed image for each frame.

  For example, if the number of frames (frame rate) of an image displayed per second in the projection display device 10 is 60 (60 Hz), one frame period is about 16.7 ms (1/60 seconds). In one frame period, the time for each LED to emit light is about 5.56 ms (1/180 seconds). Therefore, the light 80 constituting the image is not perceived by humans as red light, green light, and blue light in order, but is perceived as mixed color light in which light of three colors of respective gradations is mixed. Further, since the color of the mixed color light is determined by each pixel of the image every frame period, the light 80 constituting the image forms a full-color image.

  In order for the light 80 constituting the image to form a high-quality full-color image, it is necessary to obtain white light by mixing the light emitted by the three color LEDs of the light source unit 20. That is, the driving condition of each LED is determined so that each LED emits light with a radiation amount that can obtain white light by mixing the light emitted from the three color LEDs of the light source unit 20. There is a need. The driving condition of the LED of the light source unit 20 is, for example, a driving current value that the light source unit driving circuit unit 71 supplies to each LED of the light source unit 20. Alternatively, the driving condition of the LED of the light source unit 20 may be the ratio of the lighting period in the subframe.

  In order to realize this, in the projection display device 10 of the present invention, the control unit 30 drives the light source unit 20 based on the control data as described above. As the control data, the control data for the red LED 21, the control data for the green LED 22, and the control data for the blue LED 23 are stored in the storage unit 32 of the control unit 30. In these three control data, the target radiation amount of each LED that can obtain white light by mixing the light emitted by each LED is associated with each other. The target radiation amount of each LED is determined so as to be obtained. The control unit 30 drives each LED of the light source unit 20 under a driving condition corresponding to the target radiation amount of each LED based on the control data.

  FIG. 2 is a graph showing the control data for any one of the three color LEDs of the light source unit 20. The horizontal axis in FIG. 2 indicates the target radiation amount of the LED of the light source unit 20, and the target radiation amount increases toward the right side. The vertical axis indicates the driving condition of the LED of the light source unit 20, and the driving condition is such that the amount of light emitted from the LED increases toward the upper side. By plotting the intersection between the LED target radiation amount and the LED driving condition associated with the target radiation amount in the control data, the correspondence between the target radiation amount and the driving condition on the control data is represented by a solid line 300. Is done.

  According to the control data shown in FIG. 2, when the target radiation amount of the LED is t1, the LED is driven under the driving condition C1 such that the radiation amount of light emitted from the LED is t1. When the target radiation amount of the LED is t2 where the radiation amount is larger than t1, the radiation amount of light emitted by the LED under the driving condition C1 such that the radiation amount of light emitted by the LED becomes t2 larger than t1. This LED is driven under a driving condition C2 in which the current becomes large. Note that the control data of the other two LEDs not shown in FIG. 2 can be expressed in a similar manner, and when the target radiation amount of any one LED is changed, the target radiation amounts of the other two LEDs are changed. Be changed.

  For example, at the time of factory shipment of the projection display device 10 of the present invention, an appropriate target radiation amount of each LED that can obtain white light by mixing light emitted from each LED of the light source unit 20, and corresponding to these Appropriate driving conditions for each LED are stored as control data. Therefore, when the control unit 30 drives the light source unit 20 based on the control data, the light 80 constituting the image forms a high-quality full-color image. However, when each LED of the light source unit 20 is affected by, for example, aging or external temperature during use, when the control unit 30 drives the light source unit 20 based on the control data, any of the LEDs It is assumed that the radiation amount of the emitted light is different from the target radiation amount. As a result, it is assumed that white light cannot be obtained when the light emitted by the three color LEDs of the light source unit 20 is mixed. Furthermore, since the material of each LED of the light source unit 20 is different, for example, the degree of aging deterioration or the degree of influence of external temperature during use differs depending on each LED. Therefore, in the projection display apparatus 10 of the present invention, as described below, the control data is corrected according to the actual amount of light emitted from each LED of the light source unit 20.

<< 3. Correction of control data >>
<< 3-1. Examples of basic corrections >>
The radiation amount acquisition unit 50 acquires the radiation amount of light emitted from the light source unit 20 and outputs the radiation amount to the control unit 30 via the integration circuit unit 72. The control unit 30 compares the input radiation amount of light emitted from the light source unit 20 with the target radiation amount of the light source unit 20 at that time. When the input radiation amount of light emitted from the light source unit 20 and the target radiation amount of the light source unit 20 do not coincide with each other, the control unit 30 controls the control data so as to reduce this difference and preferably eliminate this difference. A correction value for correcting the is determined. The control unit 30 may determine a correction value for correcting the control data by, for example, referring to a table stored in the storage unit 32 by the processing unit 31. For example, the processing unit 31 is stored in the storage unit 32. It may be determined by calculating an arithmetic expression. The correction value for correcting the control data by the control unit 30 is not limited only when the input radiation amount of light emitted from the light source unit 20 and the target radiation amount of the light source unit 20 do not match, It may be when the input radiation amount of light emitted from the light source unit 20 and the target radiation amount of the light source unit 20 dissociate beyond a predetermined range. In this case, the input radiation amount of light emitted from the light source unit 20 and the target radiation amount of the light source unit 20 do not match, but when the difference is within a predetermined range, the control unit 30 corrects the control data. The correction value is not determined.

  The determination of the correction value for correcting the control data by the control unit 30 is also executed for each control data of the three LEDs included in the light source unit 20. In the following description, correction of control data of any one of the three LEDs of the light source unit 20 will be described, but the same applies to correction of control data of the other two LEDs. That is, the correction value is individually determined for the control data for the red LED 21, the control data for the green LED 22, and the control data for the blue LED 23.

  When the control data is corrected by the correction value determined by the control unit 30, the driving condition associated with the target radiation amount of the light source unit 20 is changed to a driving condition different from the driving condition based on the control data before correction. Be changed. FIG. 3 shows a solid line 300 representing the correspondence between the target radiation amount of the LED in the control data before correction and the driving condition, and a solid line 300 representing the correspondence relationship between the target radiation amount of the LED in the control data after correction and the driving condition. 'And are shown. Hereinafter, the control data before correction is also referred to as “pre-correction control data 300”, and the control data after correction is also referred to as “post-correction control data 300 ′”.

  In the example shown in FIG. 3, when the target radiation amount of the light source unit 20 is t1, the driving condition associated with the control data before correction 300 is C1, and the driving condition associated with the control data after correction 300 ′ is C1. 'Is. As described above, the pre-correction control data 300 and the post-correction control data 300 ′ have different driving conditions associated with the same target radiation amount of the light source unit 20. As described above, the correction value is determined so that the difference between the radiation amount of light emitted from the light source unit 20 input by the control unit 30 and the target radiation amount of the light source unit 20 becomes small. Therefore, by switching the control data from the pre-correction control data 300 to the post-correction control data 300 ′, the difference between the amount of light emitted from the light source unit 20 input by the control unit 30 and the target amount of radiation of the light source unit 20 is increased. Large dissociation is prevented.

  Here, when the control data of the light source unit 20 is switched from the pre-correction control data 300 to the post-correction control data 300 ′, the hue of the image (virtual image) displayed by the projection display device 10 is changed by changing the driving conditions. And / or brightness changes. Therefore, for example, when a person such as a driver of the vehicle 100 is viewing an image (virtual image) displayed by the projection display device 10, the control data of the light source unit 20 is changed from the control data before correction 300 to the control data after correction. When the mode is switched to 300 ′, there is a possibility that a person who is visually recognizing an image (virtual image) may feel uncomfortable.

  In order to prevent this, in the projection display apparatus 10 of the present invention, the control data is corrected from the control data before correction 300 to the control data after correction in relation to the start-up expression executed when the projection display apparatus 10 is started. Switch to 300 '. The start-up expression means that the control unit 30 controls the spatial light modulation unit 40 so that the first image is generated and the first image is displayed, and the amount of light emitted from the light source unit 20 is After driving the light source unit 20 to be the first target radiation amount, the radiation amount of the light emitted from the light source unit 20 gradually changes from the first target radiation amount to the second target radiation amount. The light source unit 20 is driven. The first image is a so-called opening image, for example, the manufacturer name or product name of the projection display device 10, the manufacturer name or product name of the vehicle 100, and other settings by the user of the vehicle 100. It can be a still image or a moving image. That is, the start-up expression is to display the opening image while changing the brightness.

  Further, switching the control data from the pre-correction control data 300 to the post-correction control data 300 ′ in relation to the start-up expression is during or before or after the radiation amount of light emitted from the light source unit 20 is gradually changed. The control data is switched from the pre-correction control data 300 to the post-correction control data 300 ′. This will be specifically described with reference to FIG.

  The target radiation amount t1 shown in FIG. 3 is the first target radiation amount t1 in the startup expression, and the target radiation amount t2 shown in FIG. 3 is the second target radiation amount t2 in the startup expression. That is, in the example shown in FIG. 3, when the startup expression is executed, the amount of light emitted from the light source unit 20 is the first target emission while the first image (virtual image) is displayed. The light source unit 20 is driven so as to gradually increase from the amount t1 to the second target radiation amount t2. Note that the amount of light emitted by the light source unit 20 gradually changes means that the amount of light emitted by the light source unit 20 may change evenly during the period in which the start time expression is executed. The speed at which the amount of light emitted by the light source unit 20 changes within the period in which the time expression is executed may be variable. Further, until the predetermined time elapses after execution of the start time expression is started, after the radiation amount of light emitted by the light source unit 20 is fixed at the first target radiation amount t1, the light emitted by the light source unit 20 The radiation amount may start to change to the second target radiation amount t2.

  First, the control unit 30 starts executing the start time expression, and while the start time expression is being executed, the radiation amount acquisition unit 50 acquires the amount of light emitted by the light source unit 20. For example, the control unit 30 drives the light source unit 20 under the first drive condition C1 associated with the first target radiation amount t1 in the control data 300 before correction immediately after the start-up expression is started. The radiation amount of light emitted from the light source unit 20 is input from the radiation amount acquisition unit 50. In this case, the control unit 30 compares the input radiation amount of light emitted from the light source unit 20 with the first target radiation amount t1, and changes the control data from the pre-correction control data 300 to the post-correction control data 300 ′. A correction value for correction is determined.

  Next, the control unit 30 corrects the control data while the radiation amount of the light emitted from the light source unit 20 gradually changes from the first target radiation amount t1 to the second target radiation amount t2, or before and after the change. The pre-control data 300 is switched to the post-correction control data 300 ′. For example, the control unit 30 changes the control data from the pre-correction control data 300 while the radiation amount of the light emitted from the light source unit 20 gradually changes from the first target radiation amount t1 to the second target radiation amount t2. Switch to post-correction control data 300 ′. In this case, the control unit 30 changes the driving condition of the light source unit 20 from the driving condition C1 associated with the first target radiation amount t1 in the pre-correction control data 300 to the second in the corrected control data 300 ′. The driving condition C2 ′ associated with the target radiation amount t2 is changed.

  As described above, the control unit 30 switches the control data from the pre-correction control data 300 to the post-correction control data 300 ′ while or before or after the amount of light emitted from the light source unit 20 gradually changes. Thus, the conspicuous change in the image (virtual image) caused by switching the control data is suppressed. Therefore, for example, compared to switching control data while displaying an image (virtual image) in which the brightness of the image (virtual image) does not change, the uncomfortable feeling given to a person viewing the image (virtual image) is reduced. can do. That is, in the projection display apparatus 10, it is possible to both prevent the person who is viewing the image from feeling uncomfortable and correct the control data of the light source unit 20.

  The switching of the control data from the pre-correction control data 300 to the post-correction control data 300 ′ may be gradually switched or may be switched instantaneously. When the control data is gradually switched from the pre-correction control data 300 to the post-correction control data 300 ′, for example, a change in the image (virtual image) caused by switching the control data may be conspicuous as compared with the case of switching instantaneously. It is suppressed. Further, when the control data is instantaneously switched from the pre-correction control data 300 to the post-correction control data 300 ′, for example, as compared with the case where the control data is gradually switched, calculation of the driving condition of the light source unit 20 during the switching of the control data, etc. The processing burden on the control unit 30 according to the above is reduced.

  And control part 30 will start execution of normal time expression, after execution of start time expression is completed. The normal time expression means that the control unit 30 generates a second image including the current vehicle speed of the vehicle 100, for example, controls the spatial light modulation unit 40 so that the second image is displayed, and the light source unit. The light source unit 20 is driven so that the amount of light emitted by the light 20 is the third target amount of radiation. The third target radiation amount in the normal time expression is determined according to the external illuminance information acquired by the external illuminance information acquisition unit 60. Specifically, for example, the control unit 30 increases the third target radiation amount as the illuminance outside the projection display device 10 acquired by the external illuminance information acquisition unit 60 increases, and the projection display device The third target radiation amount is determined so that the third target radiation amount decreases as the external illuminance of 10 decreases. The control unit 30 drives the light source unit 20 based on the corrected control data 300 ′ so that the amount of light emitted from the light source unit 20 becomes the third target radiation amount. In the example shown in FIG. 3, the third target radiation amount is indicated by t3, and the third drive condition associated with the third target radiation amount t3 in the corrected control data 300 ′ is C3 ′. It is shown in

  It should be noted that even when switching the control data from the pre-correction control data 300 to the post-correction control data 300 ′ is slow, the amount of light emitted from the light source unit 20 in the normal time expression becomes the third target radiation amount. In addition, the control unit 30 needs to be completed before the drive unit 20 is driven. Based on the corrected control data 300 ′, the control unit 30 drives the drive unit 20 so that white light can be obtained by mixing the light emitted by the LEDs of the light source unit 20 in the normal time expression. Each LED of the light source unit 20 can be driven under appropriate driving conditions.

<< 3-2. Correction Application Example 1 >>
In some embodiments, << 3-1. In the example of basic correction >>, the control unit 30 sets the second target radiation amount in the startup expression according to the external illuminance information acquired by the external illuminance information acquisition unit 60 when executing the startup expression. You may decide. Alternatively, the control unit 30 may perform the start-up time according to the external illuminance information acquired by the external illuminance information acquisition unit 60 when, for example, the vehicle door of the vehicle 100 is opened. A second target radiation amount in the representation may be determined.

  As described above, the third target radiation amount in the normal time expression is determined according to the external illuminance information acquired by the external illuminance information acquisition unit 60. Therefore, the control unit 30 determines the second target radiation amount in the start-up expression according to the external illuminance information acquired by the external illuminance information acquisition unit 60 when or before executing the start-up expression. When the start time expression ends and the normal time expression is executed, the brightness of the image (virtual image) can be prevented from changing greatly. As a result, the uncomfortable feeling given to the person who visually recognizes the image (virtual image) can be further reduced.

  FIG. 4A shows a third target radiation amount t3-A in the normal time expression that is associated with the external illuminance information acquired by the external illuminance information acquiring unit 60 when or before the control unit 30 executes the start time expression. Shows an example of a situation where is larger than the first target radiation amount t1 in the start-up expression. In the example shown in FIG. 4A, the second target radiation amount t2-A in the startup expression is larger than the first target radiation amount t1 in the startup expression. Therefore, in the situation shown in FIG. 4A, it is assumed that the second target radiation amount t2-A in the startup expression is determined to be smaller than the first target radiation amount t1 in the startup expression. When the time expression is finished and the normal time expression is executed, it is possible to suppress the brightness of the image (virtual image) from changing greatly.

  FIG. 4B shows the third target radiation amount t3-B in the normal time expression associated with the external illuminance information acquired by the external illuminance information acquiring unit 60 when or before the control unit 30 executes the start time expression. Shows an example of a situation where is smaller than the first target radiation amount t1 in the start-up expression. In the example shown in FIG. 4B, the second target radiation amount t2-B in the startup expression is smaller than the first target radiation amount t1 in the startup expression. Therefore, in the situation shown in FIG. 4B, it is assumed that the second target radiation amount t2-B in the start time expression is determined to be larger than the first target radiation amount t1 in the start time expression. When the time expression is finished and the normal time expression is executed, it is possible to suppress the brightness of the image (virtual image) from changing greatly.

  Note that the control unit 30 sets the second target radiation amount in the startup expression to one second target radiation amount that is larger than the first target radiation amount in the startup expression and the first target radiation in the startup expression. One of the second target radiation amounts smaller than the amount may be selected according to the external illuminance information. Further, the control unit 30 sets the second target radiation amount in the startup expression to two or more second target radiation amounts that are larger than the first target radiation amount in the startup expression and the first target radiation amount in the startup expression. Any one of two or more second target radiation amounts smaller than the target radiation amount may be selected according to the external illuminance information.

<< 3-3. Correction Application Example 2 >>
In some embodiments, << 3-1. In the example of basic correction >>, the control unit 30 performs the first target in the start time expression according to the external illuminance information acquired by the external illuminance information acquisition unit 60 when or before executing the start time expression. The radiation amount and the second target radiation amount may be determined. Specifically, as shown in FIG. 5, when the control unit 30 executes the start time expression, or before that, the first time in the normal time expression is associated with the external illuminance information acquired by the external illuminance information acquisition unit 60. The first target radiation amount and the second target radiation amount in the start-up expression may be determined based on a comparison result between the target radiation amount 3 and the threshold radiation amount tTH. The threshold radiation amount tTH is, for example, a third target radiation amount that is determined when external illuminance information that causes the above-described autolight system to automatically turn on the headlight is acquired.

  FIG. 5 shows the situation when the third target radiation amount in the normal time expression is larger than the threshold radiation amount tTH (the third target radiation amount is t3H), and the third target radiation amount in the normal time expression is the threshold value. The situation (the third target radiation amount is t3L) when it is smaller than the radiation amount tTH is shown. In the example shown in FIG. 5, when the third target radiation amount in the normal time expression becomes the third target radiation amount t3H larger than the threshold radiation amount tTH, the control unit 30 performs the first target radiation in the startup expression. Both the radiation amount t1H and the second target radiation amount t2H are determined so as to be included in the high luminance side region 400H, which is a region where the target radiation amount is larger than the threshold radiation amount tTH. On the other hand, in the example shown in FIG. 5, when the third target radiation amount in the normal time expression becomes the third target radiation amount t3L that is smaller than the threshold radiation amount tTH, the control unit 30 performs the start time expression. Both the first target radiation amount t1L and the second target radiation amount t2L are determined to be included in the low luminance side region 400L, which is a region having a target radiation amount smaller than the threshold radiation amount tTH.

  As a result, when the control unit 30 determines that the third target radiation amount in the normal expression is larger than the threshold radiation amount, both the first target radiation amount and the second target radiation amount in the startup expression are threshold values. Compared with the case where it is determined to be smaller than the amount of radiation, it is possible to prevent the brightness of the image (virtual image) from changing greatly when the start time expression ends and the normal time expression is executed. . Similarly, when the control unit 30 determines that the third target radiation amount in the normal time expression is smaller than the threshold radiation amount, both the first target radiation amount and the second target radiation amount in the startup expression are the threshold values. Compared with the case where it is determined to be larger than the radiation amount, it is possible to prevent the brightness of the image (virtual image) from changing greatly when the start time expression ends and the normal time expression is executed. .

<< 3-4. Correction Application Example 3 >>
In some embodiments, << 3-3. In the application example 2 of correction>, the control unit 30 executes the second target radiation in the start time expression according to the external illuminance information acquired by the external illuminance information acquisition unit 60 when or before executing the start time expression. The amount may be further subdivided. Specifically, << 3-2. As in the application example 1 of correction, the control unit 30 uses the first target radiation amount according to the external illuminance information acquired by the external illuminance information acquisition unit 60 when or before the start-up expression is executed. A second target radiation amount that is greater than or a second target radiation amount that is smaller than the first target radiation amount.

  As shown in the high luminance side region 400H of FIG. 6A, the third target radiation amount in the normal time expression is larger than the threshold radiation amount tTH and larger than the first target radiation amount t1H in the start time expression ( For example, at the time of the third target radiation amount t3H-A), the control unit 30 determines a second target radiation amount t2H-A that is larger than the first target radiation amount t1H. Further, as shown in the high luminance side region 400H of FIG. 6B, the third target radiation amount in the normal time expression is larger than the threshold radiation amount tTH and is larger than the first target radiation amount t1H in the start time expression. When it is small (for example, the third target radiation amount t3H-B), the control unit 30 determines a second target radiation amount t2H-B that is smaller than the first target radiation amount t1H.

  Further, as shown in the low luminance side region 400L of FIG. 6A, the third target radiation amount in the normal time expression is smaller than the threshold radiation amount tTH and is smaller than the first target radiation amount t1L in the start time expression. When it is large (for example, the third target radiation amount t3L-A), the control unit 30 determines a second target radiation amount t2L-A that is larger than the first target radiation amount t1L. Further, as shown in the low-luminance side region 400L of FIG. 6B, the third target radiation amount in the normal time expression is smaller than the threshold radiation amount tTH and is smaller than the first target radiation amount t1L in the startup expression. When it is small (for example, the third target radiation amount t3L-B), the control unit 30 determines a second target radiation amount t2L-B that is smaller than the first target radiation amount t1L.

  In this way, the control unit 30 determines the second target radiation amount in the start-up expression, for example, << 3-3. Compared with the application example 2 of correction | amendment, it can further suppress that the brightness of an image (virtual image) changes greatly, when expression at the time of starting is complete | finished and expression at the time of normal is performed.

<< 3-5. Correction application example 4 >>
In some embodiments, << 3-1. Example of basic correction> or << 3-3. In the correction application example 2>, the control unit 30 performs the third target radiation in the normal time expression associated with the external illuminance information acquired by the external illuminance information acquisition unit 60 when or before the start time expression is executed. The second target radiation amount may be determined so that the amount matches the second target radiation amount in the startup expression.

  FIG. 7A shows << 3-1. In the example of basic correction >>, the control unit 30 sets the second target radiation amount t3 in the start time expression so that the third target radiation amount t3 in the normal time expression matches the second target radiation amount t2 in the start time expression. An example in which the target radiation amount is determined will be shown. FIG. 7B shows << 3-3. Correction application example 2>, the control unit 30 causes the second target radiation amount in the start time expression to match the third target radiation amount in the normal time expression and the second target radiation amount in the start time expression. An example in which is determined will be shown. That is, in the example shown in FIG. 7B, when the control unit 30 executes the start time expression, or before that, the third time in the normal time expression is associated with the external illuminance information acquired by the external illuminance information acquisition unit 60. When the target radiation amount becomes t3Ht larger than the threshold radiation amount tTH, the control unit 30 determines the second target radiation amount t2H in the start-up expression so as to coincide with the third target radiation amount t3H. Further, in the example shown in FIG. 7B, when the control unit 30 executes the start time expression, or before that, the third time in the normal time expression is associated with the external illuminance information acquired by the external illuminance information acquisition unit 60. When the target radiation amount becomes t3L smaller than the threshold radiation amount tTH, the control unit 30 determines the second target radiation amount t2L in the start-up expression so as to coincide with the third target radiation amount t3L.

  In this way, the control unit 30 determines the second target radiation amount in the start-up expression, for example, << 3-1. Example of basic correction> or << 3-3. Compared with the application example 2 of correction | amendment, it can further suppress that the brightness of an image (virtual image) changes greatly, when expression at the time of starting is complete | finished and expression at the time of normal is performed. 7A and 7B show an example in which the third target radiation amount in the normal time expression is larger than the first target radiation amount in the start time expression, but the third target radiation amount in the normal time expression is shown. Even when the target radiation amount is smaller than the first target radiation amount in the start-up expression, the control unit 30 naturally determines the second target radiation amount to coincide with the third target radiation amount. To do.

<< 3-6. Correction Application Example 5 >>
In some embodiments, << 3-1. Example of basic correction>, << 3-2. Correction application example 1 >><< 3-3. Correction Application Example 2 >><< 3-4. Correction application example 3 >> or << 3-5. In the application example 4 of the correction, the control unit 30 within the arbitrary period from when the control unit 30 starts execution of the start expression until the start of execution of the start expression and starts execution of the normal time expression, The spatial light modulator 40 may be controlled so that the displayed image (virtual image) gradually changes from the first image to the second image. Hereinafter, a description will be given with reference to FIG.

  FIG. 8 shows an example in which the displayed image (virtual image) gradually changes from the first image to the second image. FIG. 8 shows a plurality of first images, a plurality of second images, and a plurality of synthesized images obtained by synthesizing the first image and the second image at the same time. Yes. In the example shown in FIG. 8, the plurality of first images are generated such that a portion displayed as a character is displayed lightly as time T elapses. On the other hand, in the example shown in FIG. 8, the plurality of second images are generated so that portions displayed as characters and symbols are displayed darker as time T elapses. For example, the control unit 30 generates a plurality of first images and a plurality of second images at different levels, and combines the first image and the second image at the same time point to generate the time T. A composite image that gradually changes from the first image to the second image can be obtained with the passage of time.

  In the example shown in FIG. 8, the composite image at time T0 is composed of only the first image, and the composite image at time T1 is composed of only the second image. The time point T0 may be a time point when the drive unit 20 is driven with the first target radiation amount t1 in the start time expression in FIG. 3, for example, and the time point T1 is the second time point in the start time expression in FIG. It may be the time when the drive unit 20 is driven with the target radiation amount t2. Alternatively, the time point T0 may be a time point when the drive unit 20 is driven with the first target radiation amount t2 in the start time expression in FIG. 3, for example, and the time point T1 is a normal time in FIG. It may be the time when the drive unit 20 is driven with the third target radiation amount t3 in the expression. Further alternatively, at least one of the time point T0 and the time point T1 is, for example, the third target radiation in the normal time expression from the time when the driving unit 20 is driven with the first target radiation amount t1 in the start time expression in FIG. It may be a time point until the drive unit 20 is driven by the amount t3.

  In this way, in addition to the gradual change in the amount of light emitted from the light source unit 20, the displayed image (virtual image) also changes gradually, thereby causing an image (virtual image) resulting from switching control data. ) Is further suppressed from being noticeable. Further, in some embodiments, while the displayed image (virtual image) gradually changes from the first image to the second image, the control data is changed from the control data before correction 300 to the control data after correction 300 ′. You may switch to. In this case, since the change of the displayed image (virtual image) and the switching of the control data overlap, it is further suppressed that the change of the image (virtual image) due to the switching of the control data is conspicuous.

  In the description so far, it has been described that the projection display device 10 is the projection display device (head-up display device) 10 mounted on the vehicle 100, but the range of the projection display device 10 is mounted on the vehicle 100. However, the present invention is not limited to the projection display device (head-up display device) 10. Moreover, although demonstrated so that the light source part 20 had LED of 3 colors, the light source part 20 may have LED of 4 colors or more. In this case, control data is prepared for each LED of four or more colors, and the control unit 30 switches each control data from the pre-correction control data to the post-correction control data in relation to the start-up expression.

  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 ... Projection type display apparatus, 20 ... Light source part, 21 ... Red LED, 22 ... Green LED, 23 ... Blue LED, 30 ... Control part, 31 ... Processing part 32... Storage unit 33... Input / output unit 40. Spatial light modulation unit 50. Radiation amount acquisition unit 60. External illuminance acquisition unit 71. , 72... Integration circuit, 76... Case, 100... Vehicle, 200 .. virtual image, 300... Control data (control data before correction), 300 ′. .

Claims (8)

A light source unit;
A control unit that drives the light source unit based on control data indicating a correspondence relationship between a target radiation amount of the light source unit and a driving condition of the light source unit;
A spatial light modulator that spatially modulates light emitted from the light source unit under the control of the controller to form an image;
A radiation amount acquisition unit for acquiring a radiation amount of the light emitted by the light source unit;
With
When the projection display device is activated, the control unit controls the spatial light modulation unit so that a first image is formed, and the radiation amount of the light emitted from the light source unit is first. After the light source unit is driven so that the target radiation amount is equal to the second target radiation amount, the radiation amount of the light emitted by the light source unit is different from the first target radiation amount from the first target radiation amount. Execute the start-up expression, driving the light source unit to gradually change to the target radiation amount of
The control unit reduces a difference between the radiation amount acquired by the radiation amount acquisition unit while executing the startup expression and the target radiation amount at the time when the radiation amount is acquired. A correction value for correcting the control data is determined, and the control data is corrected by the correction value while the radiation amount of the light emitted by the light source unit gradually changes or before and after the change. A projection display device that switches to control data after correction. An external illuminance information acquisition unit for acquiring external illuminance information;
The target radiation amount of the light source unit after the start time expression is completed is associated with the external illuminance information acquired by the external illuminance information acquisition unit,
The control unit determines the first target radiation amount and the second target radiation amount according to the external illuminance information acquired by the external illuminance information acquisition unit when or before executing the startup expression. The projection display device according to claim 1, which is determined. The target radiation amount of the light source unit after completion of the start-up expression, which is associated with the external illuminance information acquired by the external illuminance information acquisition unit when or before executing the start-up expression, When larger than the first target radiation amount,
While the control unit determines the second target radiation amount to be larger than the first target radiation amount,
The target radiation amount of the light source unit after completion of the start-up expression, which is associated with the external illuminance information acquired by the external illuminance information acquisition unit when or before executing the start-up expression, When smaller than the first target radiation amount,
The projection display device according to claim 2, wherein the control unit determines the second target radiation amount to be smaller than the first target radiation amount.   The control unit is associated with the external illuminance information acquired by the external illuminance information acquisition unit before or before executing the activation expression, and the light source unit after the activation expression is completed The projection display device according to claim 2, wherein the second target radiation amount is determined so that the target radiation amount matches the second target radiation amount. The control unit, within an arbitrary period from the start of execution of the start-up expression to the end of the start-up expression,
The spatial light modulation unit is controlled so as to gradually change an image to be formed from the first image to a second image different from the first image. The projection display device described in the item.   The control unit gradually switches the control data to corrected control data corrected by the correction value while or before or after the radiation amount of the light emitted by the light source unit gradually changes. The projection display device according to claim 1.   The control unit instantaneously switches the control data to corrected control data corrected by the correction value during or before the change of the amount of radiation emitted by the light source unit gradually. The projection display device according to claim 1. The light source unit includes a red light emitting element, a green light emitting element, and a blue light emitting element,
The control data includes red light emitting element control data, green light emitting element control data, and blue light emitting element control data,
The control data for the red light emitting element, the control data for the green light emitting element, and the control data for the blue light emitting element are obtained by mixing the light emitted by the red light emitting element, the green light emitting element, and the blue light emitting element. Shows the correspondence between the target radiation amount of each light emitting element such that white light can be obtained and the driving conditions of each light emitting element,
The projection display according to any one of claims 1 to 7, wherein the correction value is individually determined for control data for red light emitting elements, control data for green light emitting elements, and control data for blue light emitting elements. apparatus.

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