JP2008058519A - Projection display device with adjustment function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve uniformity of brightness of each part on a screen of a projection display device in order to accurately compare and evaluate medical electronic images and X-ray films. <P>SOLUTION: The projection display device 100 has an optical drive part 1, a projection lens 2, a return mirror 3, a first brightness detection sensor 51, a second brightness detection sensor 52, a brightness detection means 10, a control part and a screen 4 comprising display regions divided into two or more. The device acquires brightness of each division display region of the screen 4 and with the first brightness detection sensor 51, the second brightness detection sensor 52, and the brightness detection means 10, an external light volume and adjusts brightness of the division display region of the screen 4 considering the external light volume by controlling the optical drive part 1 with the control part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projection display device, and more particularly to a projection display device that projects from the back of a screen.

In a medical field, it is common to observe and diagnose an image such as an X-ray X-ray film or a magnetic resonance image (MRI) film. The X-ray image is printed on a large film. Diagnosis is made by placing this X-ray film in front of a white surface light source called Sherkasten and observing Sherkasten light transmitted through the X-ray film. In the examination of these medical images, it is required to simultaneously compare a plurality of medical images in order to make an accurate diagnosis.
Here, the Schaukasten generally has a structure in which several white fluorescent lamps are arranged on the back of a horizontally long rectangular screen, and substantially uniform white light is emitted from the screen surface. In addition, in order to make image information that is difficult to discriminate only with white light to stand out and be easy to interpret, Schaukasten using color light sources such as blue, green, and red has been proposed (see, for example, Patent Document 1). .
On the other hand, in recent years, X-ray images have been digitized and diagnosed with electronic displays. By digitizing X-ray images, it becomes easier to store and organize data, and it is expected that X-ray diagnosis on electronic displays will continue to expand in the future.

As this type of electronic display, the same resolution and gradation of medical images as those observed with X-ray films are required, and at present, a monochrome liquid crystal display of about 20 inches is used. It has been. In addition, cases in which X-ray films and X-ray electron images as described above are mixed and compared are increasing.
Therefore, if the liquid crystal display can be used as the Schaukasten, the X-ray film and the X-ray electronic image can be compared using the same display, which is convenient.
However, with this type of electronic display, it is difficult to achieve the resolution and gradation of a medical image that can withstand medical diagnosis. In addition, it is difficult to realize a luminance that can withstand use as a Schaukasten. For this reason, the fact is that the Schaukasten and the electronic display are used side by side.
JP 2000-241749 A

As described above, in order to diagnose X-ray images, it is necessary to compare a plurality of images simultaneously. The applicant of the present invention has proposed and developed to use a projection display device as means for interpreting both an image of an X-ray film and an electronic image by Schaukasten.
In such an apparatus, it is conceivable to divide the display area of one screen into a plurality of parts, and display the X-ray film and the electronic image, or the plurality of X-ray films, and further the plurality of electronic images side by side. . When such a plurality of images are compared, if the brightness of the display areas of the two is different, a delicate shadow may be overlooked and a misdiagnosis may be induced. In a bright environment, the contrast of the display area on the screen changes due to external light. If the degree of external light irradiation is partially or temporally different in the display area on the screen, the gradation of the image changes, making it difficult to compare and evaluate medical images.
Therefore, in order to compare and evaluate a plurality of images with the same accuracy, it is necessary to eliminate the influence of external light and make the luminance of each divided area uniform.
An object of the present invention is a projection display device that can be used as a large-screen and high-precision shakasten, and can also be used as an X-ray electronic image display device, and does not induce misdiagnosis in the X-ray film and X-ray electronic image display areas It is possible to realize a projection type display device that can suppress a difference in luminance and maintain a certain contrast even when the external light quantity changes.

A projection display device according to a first invention includes an optical drive unit, a projection lens, a screen, a split display control unit, a luminance detection unit, and a luminance adjustment unit. The optical drive unit includes a light source, and emits light modulated by an image signal or white light as backlight light. The projection lens expands the light emitted from the optical drive unit. Light from the projection lens is projected onto the screen. The split display control means controls the optical drive unit so that an image is displayed by being divided into a plurality of display areas on the screen. The luminance detection unit detects the luminance of light projected from the projection lens and the luminance of external light in a plurality of display areas on the screen. The brightness adjusting means adjusts the brightness of each display area on the screen based on the detection result of the brightness detecting unit.
In this apparatus, light modulated by an image signal or white light as backlight light is emitted from the optical drive unit. And the light from this optical drive part is expanded by a projection lens, and is projected on a screen. At this time, the optical drive unit is controlled, and an image is displayed by being divided into a plurality of display areas on the screen. The brightness of the light projected from the projection lens and the brightness of the outside light are detected in each of the divided display areas, and the brightness of each display area on the screen is adjusted based on the detection result. Thereby, it is possible to perform luminance adjustment in consideration of the external light amount.

According to a second aspect of the present invention, there is provided a projection display apparatus according to the first aspect, wherein the luminance detection unit includes a first sensor, a second sensor, and an external light amount calculation unit, and the luminance adjustment unit includes The detection result of the first sensor is corrected based on the calculation result of the external light amount calculation unit, and the luminance of each display area on the screen is adjusted based on the result. The first sensor detects the brightness of the light projected from the projection lens. The second sensor detects the luminance of light including light projected from the projection lens and external light. The external light amount calculation unit calculates the brightness of external light by subtracting the detection result of the first sensor from the detection result of the second sensor.
As a result, it is possible to accurately grasp the amount of external light in the environment where this device is placed, and when there is a large amount of external light, control can be performed to prevent a decrease in contrast of each divided area on the screen, and brightness adjustment can be performed. Therefore, it is possible to make a comparative diagnosis of an appropriate X-ray film and X-ray electron image even in an environment with a large amount of external light.
According to a third aspect of the present invention, there is provided the projection display device according to the first or second aspect of the invention, wherein the first sensor is disposed in a region irradiated with light emitted from the projection lens and further reflected by the screen. Has been. And the 2nd sensor is arrange | positioned in the area | region where both the light and external light which were irradiated from the projection lens and were reflected by the screen are irradiated.

In this apparatus, the first sensor can detect the brightness of the projection light from the projection lens, and the second sensor can detect the brightness of both the projection light from the projection lens and outside light.
A projection display apparatus according to a fourth aspect of the present invention is the apparatus according to any one of the first to third aspects, further comprising a folding mirror that reflects the light emitted from the projection lens and projects the light onto the screen.
In this apparatus, the light from the projection lens is reflected by the folding mirror and projected onto the screen.
A projection display apparatus according to a fifth aspect of the present invention is the apparatus according to any one of the first to fourth aspects, further comprising electronic image storage means for storing an electronic image serving as a reference for the image signal. Here, electronic image data can be held.
A projection display device according to a sixth aspect of the present invention is the device according to any one of the first to fifth aspects, wherein the optical drive unit includes an illumination optical system and a display element. The illumination optical system condenses light emitted from the light source. The display element modulates light from the illumination optical system by changing the transmittance based on the image signal.
In this apparatus, the light emitted from the light source is collected by the illumination optical system, and the display element modulates the light from the illumination optical system by changing the transmittance based on the image signal. Here, since the light from the light source is collected by the illumination optical system, the display element can be irradiated with light efficiently.

A projection display device according to a seventh invention is the projection device according to any one of the first to sixth inventions, further comprising an X-ray film holding means and an X-ray film insertion detecting means, wherein the luminance adjusting means is The brightness adjustment is executed when the X-ray film is inserted. The X-ray film holding means is disposed on the outer periphery of the screen and holds the X-ray film on the screen. The X-ray film insertion detecting means detects in which of the plurality of divided display areas on the screen the X-ray film is inserted.
Here, it is detected whether or not the X-ray film has been inserted, and the luminance adjustment with other regions is executed when the X-ray film has been inserted. Thereby, unnecessary brightness adjustment can be prevented from being executed.
A projection display device according to an eighth invention is the projection display device according to any one of the first to seventh inventions, wherein the brightness adjusting means is a minimum value from the brightness value of each divided display area of the screen acquired by the brightness detecting unit. The brightness value is determined, and the minimum brightness value area information indicating which divided display area of the screen the minimum brightness value belongs to is determined. The divided display control means controls the transmittance of the corresponding area of the display element corresponding to the divided display area other than the divided display area of the screen indicated by the minimum luminance value area information in a direction approaching the minimum luminance value. .

  As a result, it is possible to accurately adjust the brightness of the divided display area of the screen and to accurately grasp the amount of external light, and when the amount of external light is large, control is performed to prevent a decrease in contrast of each divided area on the screen. The brightness can be adjusted. Therefore, it is possible to make a comparative diagnosis of an accurate X-ray film and X-ray electron image even in an environment with a large amount of external light.

The projection display device according to the present invention has a large screen, a plurality of divided display areas on the screen, and each divided display area can be used as an X-ray electronic image display screen and a Schaukasten. Can be used as
And since the measurement result of the brightness of only the reflected light from the screen is corrected according to the external light quantity, the brightness of the divided display area on the screen can be adjusted according to the external light quantity, even if the external light quantity changes Comparison of X-ray films, comparison of X-ray electron images, and mixed comparison of X-ray films and X-ray electron images can be easily performed with high accuracy.

[First Embodiment]
<Overall configuration of projection display device>
FIG. 1 shows an overall configuration diagram of a projection display apparatus 100 according to the first embodiment of the present invention. The projection display device 100 is a rear projector, and has, for example, a screen having a size that can secure a plurality of display areas of 20 inches or more, and has a function that can be used as a shark caster.
The projection display apparatus 100 mainly includes an optical drive unit 1, a projection lens 2 that expands light emitted from the optical drive unit 1, a folding mirror 3 that reflects light from the projection lens 2, and a folding mirror 3. The screen 4 on which the reflected light from the light is projected, first and second luminance detection sensors 51 and 52, an X-ray film holding means 6, and a sensor 7 are included.
The first luminance detection sensor 51 is a sensor that detects the luminance of light projected from the projection lens 2, reflected by the folding mirror 3, and further reflected by the screen 4. The second luminance detection sensor 52 is a sensor that detects both the light projected from the projection lens 2, reflected by the folding mirror 3, further reflected by the screen 4, and the brightness of the external light that has passed through the screen 4. . The X-ray film holding means 6 is a means for holding the X-ray film F inserted into the screen 4. The sensor 7 is a sensor that detects that the X-ray film F has been inserted (hereinafter referred to as “X-ray film insertion detection sensor”).

In addition, the projection display apparatus 100 receives the signals from the luminance detection means 10 to which signals are input from the first luminance detection sensor 51 and the second luminance detection sensor 52 and the X-ray film insertion detection sensor 7. X-ray film insertion detecting means 11 for detecting that the X-ray film F has been inserted into the X-ray film holding means 6.
Further, the projection display apparatus 100 includes a microcomputer including a CPU 15, a ROM 16, a RAM 17, and the like. These are connected to the above-described luminance detection means 10 and X-ray film insertion detection means 11 through the bus 18, and are also connected to an electronic image storage means 20 and a screen display control means 21, and further to an interface. Display means 24 and input means 25 are connected through 22 and 23, respectively. The screen display control means 21 is connected to a screen display memory 26 for storing electronic image information for screen display.
The constituent members except for the display unit 24 and the input unit 25 are housed in the housing 12 or supported by the housing 12.
The optical drive unit 1 is a part that emits light modulated by an image signal or white light as backlight light, and includes a light source 30, an illumination optical system 31, and a display element 32 as shown in FIG. ing. As the light source 30, for example, an ultra-high pressure mercury lamp or the like is used. The illumination optical system 31 is a part that divides and combines the light emitted from the light source 30, and the illumination optical system 31 realizes uniform illumination on the display element 32. The display element 32 is a transmissive type, and a liquid crystal panel or the like having resolution and gradation that can withstand medical images is used. The display on the screen 4 can be changed by changing the transmittance of the display element 32.

The projection lens 2 is composed of, for example, a plurality of lenses. The projection lens 2 takes in a light beam transmitted through the display element 32 and projects it onto the folding mirror 3 shown in FIG.
The folding mirror 3 reflects the light emitted from the projection lens 2 to the screen 4, and is installed at a position where the light transmitted through the display area of the display element 32 is projected on the screen 4.
The first luminance detection sensor 51 and the second luminance detection sensor 52 are optical sensors such as photodiodes and phototransistors, for example, and convert the luminance into a physical quantity (for example, an amount of current) proportional thereto. The first luminance detection sensor 51 is installed in a range where the light reflected by the folding mirror 3 and further reflected by the screen 4 is irradiated and does not block the reflected light from the folding mirror 3 to the screen 4. The The second luminance detection sensor 52 is in a range where the light reflected by the folding mirror 3 and further reflected by the screen 4 and the external light L passing through the screen 4 are irradiated, and from the folding mirror 3 to the screen 4. It is installed in a position that does not block the reflected light.
An example of the arrangement of the first luminance detection sensor 51 and the second luminance detection sensor 52 is shown in FIG. FIG. 3 is a front view of the projection display apparatus 100. The screen 4 is composed of, for example, three divided display areas each having an aspect ratio of 4: 3 and a size of 20 inches. The size of the screen 4 is approximately 40 inches diagonally. As shown in FIG. 3, the first luminance detection sensor 51 is located at the center of the upper end of each of the three divided display areas constituting the screen 4 inside the housing 12, and the second luminance detection sensor is located at the center of the lower end. 52 is installed.

In FIG. 3, the first luminance detection sensor 51 is installed at the upper end of each of the three divided display areas constituting the screen 4, and the second luminance detection sensor 52 is installed at the lower end. The installation positions of these luminance detection sensors 51 and 52 are not limited to these. That is, the first luminance detection sensor 51 is in a range where the light reflected by the folding mirror 3 and further reflected by the screen 4 is irradiated, and at a position where the reflected light from the folding mirror 3 to the screen 4 is not blocked. You can install it anywhere. In addition, the second luminance detection sensor 52 is a range in which light reflected by the folding mirror 3 and further reflected by the screen 4 and external light is irradiated through the screen 4, and reflected from the folding mirror 3 to the screen 4. It may be installed anywhere as long as it does not block light. Further, the first luminance detection sensor 51 and the second luminance detection sensor 52 may be shared with the luminance adjustment optical sensor of the projection display apparatus 100.
The luminance detection means 10 receives the outputs from the first luminance detection sensor 51 and the second luminance detection sensor 52 and uses the luminance of the reflected light from the screen 4 detected by the first luminance detection sensor 51 to determine the screen 4. The brightness of the upper divided display area is detected. The reflected light from the screen 4 detected by the first brightness detection sensor 51 from the brightness of both the reflected light from the screen 4 and the external light L that has passed through the screen 4 detected by the second brightness detection sensor 52. The luminance of only the external light L that has passed through the screen 4 is obtained. That is, by obtaining the luminance of only the external light L, an estimated value of the external light amount under the environment where the projection display apparatus 100 is placed can be acquired.

As described above, the X-ray film insertion detection sensor 7 is a sensor that detects that the X-ray film F has been inserted into the X-ray film holding means 6 and that the X-ray film F that has been inserted has been removed. A physical quantity (for example, a change in pressure or an amount of current) indicating whether or not F is inserted into and removed from the X-ray film holding means 6 is acquired. The X-ray film insertion detection sensor 7 is installed in, for example, a pressure sensor for measuring a pressure change in a portion of the X-ray film holding unit 6 that comes into contact with the X-ray film, or a region where the X-ray film of the X-ray film holding unit 6 is inserted. An optical sensor (for example, a transmissive photointerrupter or a reflective photointerrupter) that measures changes in the amount of light transmitted or reflected is used.
The CPU 15 realizes a divided display control function together with the screen display control means 21, and the optical drive unit 1 is controlled by this divided display control function, and an image is displayed by being divided into a plurality of display areas on the screen 4. It is possible. Further, the CPU 15 adjusts the luminance of each divided display area in consideration of the external light amount from the luminance detection result of each of the divided display areas on the screen 4 and the detection result of the luminance of the external light that has passed through the screen 4. It has a function to do. Further, the CPU 15 has a function of detecting, in addition to the X-ray film insertion detection unit 11, which region on the screen 4 is inserted into the X-ray film F.

The electronic image storage means 20 stores X-ray electronic image data, and is, for example, an HDD device or a semiconductor memory.
The display unit 24 displays information such as the control contents in the CPU 15 and the like, and is a liquid crystal panel, an external monitor, or the like. The display unit 24 may share the screen 4.
The input means 25 is, for example, a keyboard, a remote controller, a touch panel, a button installed on the housing, or the like. The input unit 25 mainly displays information indicating which divided display area on the screen 4 to be used as the shearus ten (hereinafter referred to as “shakasten function realization area information”) and the X-ray electron image are displayed on the screen 4. Information indicating which of the upper divided display areas (hereinafter referred to as “electronic image display function realization area information”) and information for specifying the X-ray image (hereinafter referred to as “electronic image file information”) are input. The
With the above configuration, the projection display device 100 realizes a large screen and high-precision display on the screen 4, and each divided display area on the screen 4 can be arbitrarily used as a Schaukasten or electronic image display device. it can. Further, it is possible to adjust the luminance of the divided display area on the screen 4 in consideration of the amount of external light.

For convenience of explanation, in FIG. 1, the first luminance detection sensor 51, the second luminance detection sensor 52, the X-ray film holding means 6, the X-ray film insertion detection sensor 7, and the X-ray film F are enlarged. Although described, the size of the portion is not limited to that shown in FIG.
<Operation of projection display device>
Next, a general operation of the projection display apparatus 100 according to the first embodiment of the present invention will be described. Here, as shown in FIG. 3, the screen 4 is divided into three areas, and the middle display area (area B in FIG. 3) of the screen 4 is made to function as an X-ray electron image display area, so that both ends are displayed separately. A case where the area (areas A and C in FIG. 3) is made to function as the shear sten will be described as an example.
First, the input unit 25 designates the Schacusten function realization area as the divided display areas A and C at both ends of the screen 4, and designates the electronic image display function realization area as the middle display area B of the screen 4.
Next, electronic image file information for specifying the X-ray electronic image to be displayed in the split display area B in the middle of the screen is input by the input means 25.

The CPU 15 receives the information from the input means 25, reads out the X-ray electronic image data specified by the electronic image file information from the electronic image storage means 20, and based on the electronic image data, through the screen display control means 21, The light emitted from the illumination optical system 31 is changed to modulated light based on electronic image data by changing the transmittance of the middle part of the display element 32 (the part corresponding to the divided display area B in the middle on the screen 4). And output to the projection lens 2. This light is reflected by the folding mirror 3 and projected onto the middle divided display region B on the screen 4 where it is displayed as an X-ray electron image.
On the other hand, the CPU 15 performs control so that the transmittance is uniform at both end portions of the display element 32 via the screen display control means 21, and the light emitted from the illumination optical system 31 is white light as backlight light. To the projection lens 2. This light is reflected by the folding mirror 3 and projected onto the divided display areas A and C at both ends on the screen 4, where it is displayed as a surface light source as a shark caster.
As described above, the projection display apparatus 100 can cause the divided display area B in the middle of the screen 4 to function as an X-ray electronic image display area, and allow the divided display areas A and C at both ends of the screen 4 to function as Sharksten areas. .

<Brightness adjustment>
Next, the brightness adjustment operation will be described. FIG. 4 and FIG. 5 show operational flow diagrams of brightness adjustment of the projection display apparatus 100 according to the first embodiment of the present invention. Here, a case where the screen 4 is divided into three will be described as an example.
When the X-ray film F is inserted into the X-ray film holding means 6, information output from the X-ray film insertion detection means 11 (hereinafter referred to as “X-ray film insertion information”) is received, and the presence / absence of X-ray film insertion is determined. Determine (S101). If no X-ray film is inserted, the brightness adjustment operation is not executed.
On the other hand, when the X-ray film F is inserted into the screen 4, in any of the divided display areas of the divided display area on the screen 4 according to the X-ray film insertion information output from the X-ray film insertion detection means 11 in step S 101. It is determined whether the X-ray film F is inserted, and the information (hereinafter referred to as “X-ray film insertion area information”) is held. In step S101, it is monitored whether or not instruction information for displaying a new X-ray electronic image (hereinafter referred to as “X-ray electronic image display instruction information”) is input from the input means 25. The presence / absence of electronic image display instruction information is determined. This instruction information is held in the RAM 17. If there is no X-ray electronic image display instruction information, the brightness adjustment operation is not executed.

As described above, in this apparatus, the brightness adjustment operation is executed only when the X-ray film is inserted or when a new X-ray electronic image display instruction is issued. Thereby, unnecessary luminance adjustment can be prevented.
When an X-ray film is inserted or when there is an instruction to display a new X-ray electronic image, a counter value n for counting the number of brightness adjustment operations is initialized (n = 0) ( S102) Every time the brightness adjustment operation is started, the counter value n is incremented, and the counter value n is held (S103).
Next, it is determined whether or not the counter value n exceeds a certain value nth (S104). If the counter value n exceeds the certain value nth, it is determined that the brightness cannot be adjusted accurately, and a warning display to that effect is displayed ( S106). This warning display is performed by displaying on the display means 24 or the screen 4. The value of nth may be set in advance, or may be input from the input means 25 by the operator at the time of use.
When the counter value n does not exceed the predetermined value nth, the luminance detection means 10 calculates the luminance value J corresponding to each divided display area on the screen 8 divided into three from the output of the first luminance detection sensor 51. Obtain (S105). Further, the luminance detecting means 10 outputs the luminance value L1 of the external light L that has passed through the screen 8 and the luminance value J corresponding to each divided display area on the screen 8 divided into three by the output of the second luminance detecting sensor 52. The total luminance value (L1 + J) is acquired (S105). The luminance detection means 10 holds these acquired values in a state where the CPU 15 can access them.

Since the first luminance detection sensor 51 is installed in an area where the external light L does not enter, the luminance value acquired by the first luminance detection sensor 51 is the luminance value of only the reflected light from the screen 8. Since the second luminance detection sensor 52 can be approximated and is installed in a region where both the external light L and the reflected light from the screen 8 are irradiated, the luminance value acquired by the second luminance detection sensor 52 is The total luminance value of both the external light and the reflected light from the screen 8 can be approximated. And the brightness | luminance detection means 10 subtracts the brightness | luminance value J acquired from the output of the 1st brightness | luminance detection sensor 51 from the brightness | luminance value (L1 + J) acquired from the output of the 2nd brightness | luminance detection sensor 52, and only external light quantity is obtained. An approximate value L1 of luminance values (hereinafter referred to as “external light intensity luminance value L1”) is acquired and held in an accessible state by the CPU 15 (S107). The external light intensity luminance value L1 is acquired when the screen 4 is divided into three, and the average value of the external light intensity luminance values acquired in the respective divided display areas is set as the external light intensity luminance value L1. Alternatively, the external light intensity luminance value acquired in any one divided display area may be set as the external light intensity luminance value L1.
Next, it is determined from the X-ray film insertion area information whether or not the luminance value acquired in step S105 is that of the divided display area on the screen 4 into which the X-ray film is inserted (S108). Then, if the luminance value is in the divided display area where the X-ray film is inserted, the acquired luminance value is set as the determination value A (S109), and the divided display area where the X-ray film is not inserted is set. If it is, the value corrected by the following equation is set as the determination value A (S110), and this value is held.

A = (luminance value) × B + C
Here, C is the shift amount and B is a coefficient.
The reason why the correction is performed by the above formula is as follows.
That is, the divided display area on the screen 4 in which the X-ray film is inserted and used as the Schaukasten is controlled to be divided so that the entire corresponding area on the display element 32 is uniform with high transmittance. On the other hand, the divided display area on the screen 4 displaying the electronic image is subjected to divided display control so that electronic image light modulated with reference to the electronic image data corresponding to the display element 32 is generated. Yes. Therefore, the divided display area on the screen 4 displaying the electronic image is transmitted through the display element 15 and less in the amount of light projected on the screen 4 than the divided display area used as the schacus ten. For this reason, it is necessary to correct by the above formula so as to realize accurate brightness adjustment.
Next, the external light intensity luminance value L1 is compared with the threshold value th_L1 (S111). When the L1 value does not exceed the th_L1 value, the determination value A is held as it is, and the L1 value exceeds the th_L1 value. If so, the determination value A is corrected by (Equation 2), and the corrected A value is held (S112).

A = (A−D) × K
Here, D is a shift amount and K is a coefficient. Note that the value of th_L1 is determined by the type of the projection display apparatus 100, for example.
The value of th_L1 may be set in advance or may be input from the input unit 25 by the operator.
When the L1 value exceeds the th_L1 value, the amount of external light is large, and the display of the X-ray electron image on the screen 8 or the light transmitted through the X-ray film is entirely white, or partially Since there is a high possibility that the image is white and difficult to see, it is necessary to control the optical drive unit 5 so as to further reduce the luminance of the three divided display areas on the screen 8.
Therefore, the determination value A is lowered by the value of D and the dynamic range is expanded by multiplying by K. Thereby, even when the amount of external light is large, it is possible to avoid a state in which the display on the screen 8 is entirely white or partially whitened, and a certain contrast can be secured. Note that K = 1 may be set. In this case, the luminance level is simply shifted in the direction of lowering, but this is also effective. Further, the value of K may be any value as long as a partially whitened state does not occur.

Note that when the average value of the external light intensity luminance values acquired in the respective divided display areas is set as the L1 value, or the external light intensity luminance value acquired in any one of the divided display areas is set as the external light intensity luminance value L1. In such a case, the processes in steps S108 to S110 are performed using the same L1 value for each divided display area.
Next, using the determination value A held, the processing from step S115 is performed. Since the process after step S115 is the same process as the above-mentioned step S111, description is abbreviate | omitted here.
As described above, according to the projection display device according to the present embodiment, even when the amount of external light is large, the luminance can be adjusted according to the amount of external light, so comparison of X-ray films, comparison of X-ray electronic images, The mixed comparison of the X-ray film and the X-ray electronic image can be easily performed with high accuracy.
Next, the minimum value of the A value of each divided display area on the screen 4 divided into three is substituted for the min value, and the divided display area information indicating the divided display area where the A value is the minimum is substituted for the ryouiki value. , Keep those values. Then, it is determined whether or not the difference between the A value and the min value of each divided display area on the screen 4 is equal to or less than the threshold value th (S114). If it is not less than or equal to the threshold th, the luminance adjustment is executed so that the luminance values other than the divided display area on the screen 4 corresponding to the ryouiki value match the min value.

That is, control is performed to reduce the transmittance of the area on the display element 32 of the optical drive unit 1 corresponding to the divided display area other than the divided display area on the screen 4 corresponding to the ryouiki value (S115). For example, if the A value of the middle divided display area of the screen 4 divided into three is a min value, the upper and lower two areas of the display element 32 other than the middle divided into three (3 of the display element 32 in FIG. 2). The upper and lower areas of the divided areas correspond to this.)
Note that the value of th is, for example, 15 [cd / m ² ] within 5% of each divided display area luminance.
The value of th may be set in advance or may be input from the input unit 25 by the operator.
Thereafter, the processing from step S103 is repeatedly executed. If it is determined in step S114 that the threshold value is equal to or less than the threshold value th, the luminance adjustment is completed. In this way, by setting the threshold value th and adjusting the brightness so that the threshold value is less than or equal to this threshold value, it is possible to prevent the number of times of the brightness adjustment from being excessively increased, and it is possible to perform accurate brightness adjustment. .
As described above, the surface light source (Shakasten) function and the electronic image display function for the X-ray film can be realized in an arbitrary area of the divided display area of the screen 4, and the luminance adjustment of the divided display area on the screen 4 can be performed. This can be performed in consideration of the amount of external light, and the X-ray film and the X-ray electron image can be easily compared.

[Other Embodiments]
(A) As shown in FIG. 6, the optical drive unit 1 may be configured to use three display elements 32r, 32g, and 32b. In this case, the light from the light source 30 and the illumination optical system 31 is decomposed into RGB light by the first dichroic mirror 40, the second dichroic mirror 41, and the three total reflection mirrors 42, 43, and 44. The display elements 32r, 32g, and 32b are used for R component, G component, and B component, respectively. The light passing through the three display elements is collected by the dichroic prism 45 and emitted to the projection lens 2.
When three display elements are used as described above, the same control may be performed for the divided display areas on the screen 4 and the corresponding areas of the three display elements 15.
(B) In the above-described embodiment, the first luminance detection sensor 51 is installed in the region irradiated with the reflected light from the screen 4, but the reflected light from the folding mirror is directly applied as shown in FIG. You may install in the area | region which is irradiated and the area | region which does not block irradiation to the screen 4 of the said reflected light. In this case, the amount of received light is larger than when the first luminance detection sensor 51 receives the reflected light from the screen 4, so that the amount of light received may be corrected and the same processing as in the above-described embodiment may be performed.

(C) In the above-described embodiment, a transmissive display element is used as a display element. However, a projection display apparatus may be configured by using a reflective display element.
(D) In the above-described embodiment, the rear type projection display apparatus using the folding mirror has been described. However, a projection display apparatus that does not use the folding mirror may be used. In this case, the light emitted from the projection lens is directly projected on the screen.

  The projection display device according to the present invention is useful in the medical-related industrial field because it can realize high-accuracy and accurate comparison and judgment of X-ray films and medical image images, and the projection display device according to the present invention. Can be implemented in the art.

1 is an overall configuration diagram of a projection display device according to a first embodiment of the present invention. FIG. 2 is a configuration diagram of an optical drive unit and a projection lens of the projection display device. 1 is a front view of a projection display device according to a first embodiment of the present invention. 6 is a brightness adjustment operation flow of the projection display apparatus according to the first embodiment of the present invention. 6 is a brightness adjustment operation flow of the projection display apparatus according to the first embodiment of the present invention. The block diagram of the optical drive part and projection lens of the projection type display apparatus which concern on other embodiment of this invention. The whole block diagram of the projection type display apparatus which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical drive part 2 Projection lens 3 Folding mirror 4 Screen 51 1st brightness | luminance detection sensor 52 2nd brightness | luminance detection sensor 6 X-ray film holding means 7 X-ray film insertion sensor 10 Luminance detection means 11 X-ray film insertion detection means 15 CPU
16 ROM
17 RAM
20 Electronic image storage means 21 Screen display control means 24 Display means 25 Input means 30 Light source 31 Illumination optical system 32, 32r, 32g, 32b Display element 100 Projection display apparatus F X-ray film
L Outside light

Claims (8)

An optical drive unit that includes a light source and emits light modulated by an image signal, or white light as backlight light;
A projection lens for enlarging the light emitted from the optical drive unit;
A screen on which light from the projection lens is projected;
On the screen, divided display control means for controlling the optical drive unit so as to display an image divided into a plurality of display areas;
A luminance detector that detects the luminance of light projected from the projection lens and the luminance of external light in a plurality of display areas on the screen;
Brightness adjusting means for adjusting the brightness of each display area on the screen based on the detection result of the brightness detection unit;
A projection display device comprising: The brightness detector is
A first sensor for detecting the brightness of light projected from the projection lens;
A second sensor for detecting brightness of light including light projected from the projection lens and external light;
An external light amount calculation unit for obtaining an external light amount in each display area on the screen based on detection results of the first sensor and the second sensor,
The brightness adjusting means includes
The detection result of the first sensor is corrected based on the calculation result of the external light amount calculation unit, and the brightness of each display area on the screen is adjusted based on the result.
The projection display device according to claim 1. The first sensor is disposed in a region irradiated with light irradiated from the projection lens and further reflected by the screen,
The second sensor is disposed in a region irradiated with both light reflected from the projection lens and further reflected by the screen and external light.
The projection display device according to claim 1.   The projection display device according to claim 1, further comprising a folding mirror that reflects light emitted from the projection lens and projects the light onto the screen.   The projection display apparatus according to claim 1, further comprising an electronic image storage unit that stores an electronic image serving as a reference of the image signal. The optical drive unit is
An illumination optical system for collecting the light emitted from the light source;
A display element that modulates light from the illumination optical system by changing the transmittance based on an image signal;
A projection display device according to claim 1, comprising: X-ray film holding means arranged on the outer periphery of the screen and holding the X-ray film on the screen;
X-ray film insertion detecting means for detecting in which of the plurality of divided display areas on the screen the X-ray film is inserted,
The brightness adjusting means performs brightness adjustment when the X-ray film is inserted,
The projection display device according to claim 1. The luminance adjusting means determines a minimum luminance value from the luminance values of the respective divided display areas of the screen acquired by the luminance detection unit, and determines which divided display area of the screen the minimum luminance value belongs to. To determine the minimum luminance value area information to be shown,
The divided display control means controls the transmittance of the corresponding area of the display element corresponding to the divided display area other than the divided display area of the screen indicated by the minimum luminance value area information in a direction approaching the minimum luminance value. Is,
The projection display device according to claim 1.

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