JP3698162B2 - Light transmissive sheet, rear projection projector, light transmissive sheet manufacturing apparatus, program, and computer-readable recording medium - Google Patents

Description

  The present invention relates to a light-transmitting sheet, a rear projection projector, a light-transmitting sheet manufacturing apparatus, a program, and a computer-readable recording medium that can eliminate a ghost image caused by retroreflection of projected light and obtain a high-resolution image. .

  A general rear projection projector includes a projector device installed in a housing, a mirror that reflects projection light emitted from the projector device, and a transmissive screen provided on the front surface of the housing. The transmissive screen also functions as a convex lens that bends the projected light so that the projected light that is enlarged and projected outward by the projection lens is directed toward the viewer and is almost perpendicular to the screen. This is a structure in which a lens sheet is combined with a lenticular lens sheet that controls the diffusion direction of projection light.

  In the rear projection projector, it is known that a ghost image due to retroreflection is generated on a screen due to its structure as the depth dimension is reduced. In particular, a rear projection projector for home use is required to be thin with respect to the degree of freedom of installation location, so that a transmissive screen and a mirror are close to each other. Therefore, retroreflection occurs between the incident surface of the transmission screen and the mirror, which is a factor that makes it easy to generate a ghost image.

  FIG. 9 is an explanatory diagram of the generation principle of a ghost image resulting from this retroreflection. The projection light L projected from the projector device is reflected by the mirror 1 and enters the Fresnel lens sheet 2. Subsequently, the regular projection light Lc, which is the original image light, enters the lenticular lens sheet 3 and is projected on the observation side. On the other hand, a part of the projection light L incident on the Fresnel lens sheet surface is reflected by the sheet surface 2a. The reflected light Lr is reflected again by the mirror 1 to become retroreflected light, is incident on the Fresnel lens sheet 2, is projected through the lenticular lens sheet 3, and becomes a ghost image Lg.

  Currently, as a technique for eliminating the ghost image, a concavo-convex shape is formed on the surface of the lens sheet where the Fresnel lens is not formed in order to erase the ghost image caused by retroreflection. Techniques exist that prevent reflection and reduce ghost images. The concavo-convex shape is a saddle shape such as a satin, a hairline, or a lenticular lens (for example, see Patent Document 1).

  There is also a technology for preventing ghost images by forming a mat surface with fine irregularities on the surface of a light diffusing sheet containing fine particles, which is attached to the Fresnel lens sheet, and diffusing the light retroreflected by the mat surface. Exists. The mat surface is formed by a thermal transfer method using a metal mold, a blast method, a hairline process, or the like (for example, see Patent Document 2).

JP-A-5-158153 JP-A-11-133508

  However, in the lens sheet described in Patent Document 1, hairlines and lenticulars are mainly used as the concavo-convex shape. However, the hairlines and lenticulars have a regular shape in one direction and a lenticular lens having a transmission screen. Therefore, there is a problem that moire occurs due to interference with the lenticular lens. In addition, although satin is cited as an example of the uneven shape, it is not disclosed whether the technical problem disclosed in the same document can be solved by using what is concretely used as satin, and the invention is not completed in this respect It has become.

  Further, in the transmissive screen described in Patent Document 2, although a fine uneven shape is formed on the mat surface, a haze value representing the degree of cloudiness is used as a scale for defining the fine unevenness (total light transmittance). Is the same definition). However, retroreflection is a phenomenon caused by the state of the incident surface of the Fresnel lens sheet, and this surface state cannot be expressed by a scale representing the state inside the object such as the haze value. Even if a desired haze value is obtained by the fine particles contained in the light diffusion sheet, retroreflection itself cannot be prevented if the surface of the light diffusion sheet is flat.

  Furthermore, the document discloses that the haze value is preferably 5% to 80%. However, when the haze value increases, the image on the screen becomes blurred and difficult to view. As a result of the test conducted by the present applicant, when the haze value is 50% or more, it is difficult to say that the image has a large blur and has a high resolution. For this reason, in order to obtain a high-resolution image, it is preferable to make the haze value as small as possible. Further, this document has demonstrated that the ghost reduction effect can be obtained when the haze value is set to 35% and 40%. However, as a result of the test conducted by the present applicant, the brightness of the projection light and the contrast of the image are demonstrated. In some cases, the ghost reduction effect is not always obtained.

  The present invention has been made in view of the above, and is a light transmissive sheet, a mirror and a rear projection projector, which can eliminate a ghost image caused by retroreflection of projection light and obtain a high resolution image, and light transmission. It aims at providing an adhesive sheet manufacturing apparatus.

  In order to achieve the above-described object, the light transmissive sheet used in the rear projection projector according to the present invention forms fine irregularities on the incident surface on which the projection light of the image is incident, and the glossiness of the incident surface due to the fine irregularities. (Gs60 °) is 35% or less.

  In a rear projection type projector, retroreflection is reflected by the incident surface of a light-transmitting sheet such as a Fresnel lens sheet as described above, and this is caused by reflection again by a mirror. If the reflected light is diffused by forming the ghost image, the ghost image can be eliminated. At this time, it is preferable to use the glossiness that defines the surface state of the incident surface as a scale that defines the fine irregularities of the incident surface. Since retroreflection is caused by reflection on the incident surface, it is not appropriate to define fine irregularities formed on the surface using a haze value indicating the degree of fogging as a scale.

  In addition, the light-transmitting sheet needs to efficiently transmit regular projection light that is image light so as not to affect the image quality as much as possible. However, conventionally, the haze value is increased and clouded to scatter light and make it difficult to see the ghost image, and the haze value has been used as a scale. However, considering the cause of the occurrence of retroreflection, the conventional method cannot prevent retroreflection depending on conditions even though the haze value is high, and also reduces the resolution of the image. In addition, conventionally, there are no problems and solutions for keeping the haze value low (the image resolution is high) and preventing retroreflection.

  Therefore, in the present invention, fine unevenness formed on the surface with glossiness (Gs 60 °) is defined so that the ghost image due to the retroreflection is eliminated and the resolution is not reduced. As a result, it is possible to avoid the occurrence of retroreflection while maintaining the resolution, so that the ghost image cannot be observed.

In addition, this light-transmitting sheet may be integrated with the Fresnel lens sheet or may be a separate body as described in the following embodiment. Furthermore, the arrangement position of the light transmissive sheet is not particularly limited as long as it is between the Fresnel lens sheet and the mirror and on the optical axis of the projection light.
The light transmissive sheet used in the rear projection projector according to the next invention is characterized in that, in the above configuration, the haze value is 33% or less. By setting the haze value to 33% or less, it is possible to maintain high resolution while suppressing the influence on image quality such as brightness and contrast.
The light-transmitting sheet used in the rear projection projector according to the next invention has randomly formed fine irregularities having a hemispherical shape, a substantially conical shape, a cylindrical shape, and other curved surfaces on an incident surface on which image projection light is incident. It is characterized by.

Since the projection light diffuses to the surroundings due to the fine uneven surface, it is possible to further prevent the generation of a ghost image. In addition, a cylindrical lens such as a conventional lenticular lens is regularly arranged in a certain direction, and thus has directionality, causing interference with a lenticular lens having the same directionality and causing moire. However, in the present invention, since the fine irregularities having a cylindrical curved surface are randomly formed with respect to the direction, size, and shape, there is no directivity, and no moire is generated because there is no interference with the lenticular. Further, when the shape is hemispherical or substantially conical, the retroreflected light can be diffused in all directions, which is more effective.
The light-transmitting sheet used in the rear projection projector according to the next invention randomly forms hemispherical or substantially conical fine irregularities on the incident surface on which the image projection light is incident, and the height difference of the fine irregularities is 5 μm. It is characterized by being 15 μm or less and a maximum diameter of 35 μm or more and 65 μm or less.

When the height difference and the maximum diameter of the hemispherical or substantially conical fine irregularities were tested while changing the dimensions, when the height difference was 5 μm or more and 15 μm or less and the maximum diameter was 35 μm or more and 65 μm or less, a favorable result for ghost image erasure Obtained.
A light transmissive sheet used in a rear projection projector according to the next invention is characterized in that, in the above configuration, a random pattern of the fine irregularities is generated, and the fine irregularities are formed by an ink jet method according to the pattern.

When printing by the inkjet method, for example, a random pattern of fine irregularities can be generated by a computer, and the pattern can be printed on a light-transmitting sheet. Compared to thermal transfer of a fixed pattern by a mold, pattern generation and manufacturing Is extremely easy. Furthermore, since printing is performed directly on the surface of the light transmissive sheet, the shape can be flexibly changed with time, and the shape of the fine irregularities can be freely set. For example, preparing a plurality of fixed patterns, selecting a fixed pattern at random during printing of a pattern on a single light-transmitting sheet, and forming fine irregularities based on the selected pattern In addition, fine irregularities can be formed in different patterns unique to each of the plurality of light transmissive sheets. Further, since no mold is used, no waste mold is generated when the pattern is changed, and the cost is low and the environment is high.
The rear projection projector according to the next invention is characterized in that an exit surface of the light transmissive sheet is a Fresnel lens of a transmissive screen. The transmission screen of a normal rear projection projector has a configuration in which a Fresnel lens sheet and a lenticular lens sheet are combined. In the present invention, the Fresnel lens sheet and the light transmissive sheet can be integrated by forming fine irregularities on the light incident surface of the light transmissive sheet and forming a Fresnel lens on the light emission surface, and the sheet is generated between the two sheets. The optical path length can be shortened. Moreover, by integrating, the number of interfaces can be reduced and the transmittance can be further improved.
In the rear projection type projector according to the next invention, the light transmissive sheet is installed between a Fresnel lens sheet and a mirror constituting the transmissive screen, and the light transmissive sheet has the incident surface and / or the light exit surface. It is characterized in that fine irregularities are formed.

By installing the light-transmitting sheet between the Fresnel lens sheet and the mirror, the projection light that has been directly incident on the incident surface of the Fresnel lens sheet can be scattered by the fine irregularities of the light-transmitting sheet. Reflection is prevented and ghost images can be eliminated. Moreover, since the reflected light reflected by the incident surface of the Fresnel lens sheet can be diffused by the exit surface of the light transmissive sheet, the ghost image can be similarly eliminated. The fine unevenness may be formed on either the incident surface or the exit surface of the light transmissive sheet.
The light-transmitting sheet manufacturing apparatus according to the next invention includes a pattern generating means for generating a fine unevenness pattern for randomly arranging fine unevenness on a light-transmitting sheet to be printed, and an ink jet according to the generated pattern. And a fine uneven pattern printing means for forming fine unevenness on the transparent sheet.

In order to form fine irregularities on the light-transmitting sheet, the ink jet method is suitable for the reason described above. In addition, when fine irregularities are regularly formed, when a display device having a fixed pixel such as a liquid crystal device as well as a lenticular lens is used as a projection image source, moire is caused by interference between the regular fine irregularities and the pixel pattern. appear. In this light transmissive sheet manufacturing apparatus, the fine irregularities are arranged on the light transmissive sheet based on the pattern generated by the pattern generating means for generating random fine irregular patterns so that the arrangement of the fine irregularities is not regular. Printing is performed by an inkjet method. As a result, moire is not generated even when a display device having fixed pixels is used.
The light-transmitting sheet manufacturing apparatus according to the next invention is characterized in that, in the above-mentioned configuration, further includes a fine uneven shape selecting means for selecting the shape of fine unevenness formed on the light transparent sheet from a plurality of samples. . Unlike the case of using a conventional mold, printing directly by the ink jet method allows you to select various uneven shapes by selecting the shape of minute unevenness immediately or by changing the shape over time. The glossiness of the fine irregularities can be easily and freely adjusted. For example, preparing a plurality of fixed patterns, selecting a fixed pattern at random during printing of a pattern on a single light-transmitting sheet, and forming fine irregularities based on the selected pattern In addition, fine irregularities can be formed in different patterns unique to each of the plurality of light transmissive sheets.
The program according to the next invention is a computer that generates a pattern of fine irregularities for randomly arranging fine irregularities on a light-transmitting sheet to be printed, and according to the generated pattern, transmits light by inkjet. It is made to function as a fine uneven | corrugated pattern printing means which forms fine unevenness | corrugation on a sheet | seat.
A computer-readable recording medium on which a program according to the following invention is recorded comprises: a pattern generating means for generating a fine uneven pattern for randomly arranging a computer on a light-transmitting sheet to be printed; According to the pattern, it is made to function as a fine uneven | corrugated pattern printing means which forms fine unevenness | corrugation on a light transmissive sheet | seat with an inkjet.

  As described above, the light-transmitting sheet of the present invention is used in a rear projection projector, and has fine irregularities formed on an incident surface on which image projection light is incident, and the glossiness (Gs60) of the incident surface due to the fine irregularities. )) To be 35% or less, a scattering effect is imparted to the incident surface, and a ghost image caused by retroreflection of the projection light generated between the mirror and the Fresnel lens sheet is eliminated. A resolution image can be obtained.

  Further, in the light transmissive sheet of the present invention, the ghost image due to retroreflection can be eliminated while maintaining the resolution of the image by setting the haze value of the light transmissive sheet having minute unevenness to 33% or less. .

  In the light transmissive sheet of the present invention, the incident surface is formed by randomly forming fine irregularities having a hemispherical shape, a substantially conical shape, a cylindrical shape, and other curved surfaces on an incident surface on which image projection light is incident. In addition, the regularity can be eliminated while further improving the scattering effect of the ghost image, and the generation of ghost images is prevented and moire is not generated.

  Further, in the light transmissive sheet of the present invention, hemispherical or substantially conical fine irregularities are randomly formed on the incident surface on which the image projection light is incident, and the height difference of the fine irregularities is not less than 5 μm and not more than 15 μm. When the diameter is 35 μm or more and 65 μm or less, the scattering effect of the incident surface can be controlled, and the ghost image can be more effectively eliminated.

  In the light transmitting sheet of the present invention, a random pattern of the fine unevenness is generated, and the fine unevenness is formed according to the pattern by an ink jet method, so that the degree of freedom of complex pattern generation and combination is high and easy. it can. Moreover, since it can print directly on the light transmissive sheet | seat surface, manufacture is facilitated. Furthermore, since no mold is required, no waste mold is generated, and the cost is low and the environment is excellent.

  In the rear projection projector of the present invention, the Fresnel lens of the transmissive screen is formed on the exit surface of the light transmissive sheet, so that the light transmissive sheet and the Fresnel lens sheet can be integrated and the number of interfaces is reduced. be able to. Accordingly, it is possible to provide a rear projection projector that can further improve the transmittance, prevent the generation of a ghost image due to retroreflection, and capture a high-resolution image.

  In the rear projection projector of the present invention, the light transmissive sheet is installed between a Fresnel lens sheet and a mirror constituting the transmissive screen, and is provided on an incident surface and / or an emission surface of the light transmissive sheet. By forming the fine irregularities, an effect can be obtained even with the light-transmitting sheet alone, and a light-transmitting sheet that prevents a ghost image due to retroreflection can be provided.

  Further, in the light transmissive sheet manufacturing apparatus, the program, and the computer-readable recording medium on which the program is recorded, the fine concavo-convex pattern for randomly arranging the fine concavo-convex on the light transmissive sheet to be printed is provided. According to this generated pattern, fine irregularities are formed on the light-transmitting sheet by ink jetting, so that the fine irregularities can be freely formed on the light-transmitting sheet.

  In addition, the light transmissive sheet manufacturing apparatus of the present invention is equipped with a fine concavo-convex shape selection means for selecting the shape of the fine concavo-convex formed on the light transmissive sheet from a plurality of samples. The glossiness (Gs60 °) of the fine irregularities can be easily adjusted.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same.

[Embodiment 1]
FIG. 1 is a block diagram showing a rear projection type liquid crystal projector according to Embodiment 1 of the present invention. The rear projection type liquid crystal projector 100 includes a projector device (not shown), a mirror 1 provided on the inner surface of the casing, and a transmission screen 4 composed of a Fresnel lens sheet 2 and a lenticular lens sheet 3. On the incident surface 2a of the Fresnel lens sheet 2, fine irregularities 5 are randomly formed with almost no gap. The fine irregularities 5 are formed of hemispherical protrusions as shown in FIG. 2, and are formed by an ink jet method (details will be described later), a cast method, an extrusion method using a metal mold, or the like.

  As the material of the Fresnel lens sheet 2, it is desirable to use a synthetic resin material such as polyvinyl chloride, polycarbonate, polymethacryl, polystyrene, polyethylene, polyester, and the like because it can be easily molded. When the fine unevenness 5 is formed by the ink jet method, it is preferable to print and mold the same material as the material of the Fresnel lens sheet 2, but the same effect can be obtained by printing and molding a material different from the Fresnel lens sheet 2. . If different materials can be used, the material of the Fresnel lens sheet 2 can be selected and used without being restricted by the material of the Fresnel lens sheet 2 and suitable for the ink jet method or optically suitable for light diffusion. Further, according to the extrusion method using a casting method or a metal mold, fine irregularities can be formed at the same time when the light-transmitting sheet itself is formed, so that the production efficiency is good.

For example, in the case of the substantially conical shape shown in FIG. 3, the fine irregularities 5 have a height difference of about 10 μm and a maximum diameter of about 50 μm, and are desirably arranged closely without a gap. In this case, the effect can be most efficiently obtained. Further, the Fresnel lens sheet 2 having such fine irregularities 5 is adjusted in the shape or arrangement of the fine irregularities so that the glossiness (Gs 60 °) is 35% or less and the haze value is 33% or less. It has been confirmed that the ghost is hardly visually recognized with high resolution at this numerical value from the test by the present applicant. Table 1 shows the test results by the applicant.
Table 1 Subjective evaluation of haze and blur amount of various diffusers

For example, in the case of the substantially conical shape shown in FIG. 3, the fine irregularities 5 have a height difference of about 10 μm and a maximum diameter of about 50 μm, and are desirably arranged closely without a gap. In this case, the effect can be most efficiently obtained. Further, the Fresnel lens sheet 2 having such fine irregularities 5 is adjusted in the shape or arrangement of the fine irregularities so that the glossiness (Gs 60 °) is 35% or less and the haze value is 33% or less. It has been confirmed that the ghost is hardly visually recognized with high resolution at this numerical value from the test by the present applicant. Table 1 shows the test results by the applicant.
Table 1 Subjective evaluation of haze and blur amount of various diffusers

  The projection light L from the projector device is reflected by the mirror 1 and enters the incident surface 2 a of the Fresnel lens sheet 2. Here, the regular projection light Lc that is image light is projected from the lenticular lens sheet 3 to the observation side. On the other hand, the reflected light Lr on the incident surface 2 a which has been a ghost image Lg in the past is scattered by the fine irregularities 5 so that the light intensity is attenuated and does not enter the Fresnel lens sheet 2 again. Thereby, the reflected light Lr does not overlap the image light Lc, and the generation of a ghost image can be prevented. In addition, the effect of eliminating ghost images can be obtained while keeping the haze value low, so the effect on image quality can be suppressed, and the resolution of images can be increased compared to conventional methods, eliminating ghost images. A good image can be obtained with high resolution.

  Further, the shape of the fine irregularities 5 is not limited to the hemispherical shape shown in FIG. 2, but may be a substantially conical shape having a rounded tip as shown in FIG. As described above, the surface with fine irregularities (same as the shape of FIG. 4 below) has high diffusibility of the projection light L and is effective in preventing retroreflection. The fine irregularities 5 are preferably projections having curved surfaces in order to obtain high light diffusibility. In addition, it is possible to obtain a low glossiness (Gs 60 °) by densely arranging so as not to leave a flat portion, and the effect of preventing retroreflection can be enhanced. Further, the shape of the fine irregularities 5 does not need to be a complete curved surface, and the same effect can be obtained even if the curvature of the curved surface varies somewhat. Furthermore, the intensity of the glossiness (Gs 60 °) can be adjusted by changing the curvature or by changing the height difference of the fine irregularities 5 within a predetermined range.

  Further, as shown in FIG. 2, the fine unevenness 5 may be formed by randomly combining a plurality of types of hemispherical projections having different height differences and maximum diameters. This configuration is characterized in that it is formed by randomly changing the dimensions of the fine irregularities 5. Like the conventional hairline, it was regularly formed and has directionality, which caused interference with the lenticular lens and caused moiré. This prevents the generation of moire. In particular, by arranging a plurality of types of hemispherical projections having different height differences and maximum diameters at random, the shape of the fine irregularities 5 becomes more complicated and discrete, and a ghost image can be prevented without causing moire.

Furthermore, as shown in FIG. 4, the fine irregularities 5 may be formed by randomly combining the projection shapes of a cylinder shape 5c, a half donut shape 5d, a cross-sectional mountain shape 5e, a cone shape 5f, and a hemispherical shape 5g. According to this configuration, a mixture of various shapes results in a complicated fine unevenness 5 shape, and the diffusibility of incident light is extremely improved, so that the ghost image elimination effect is high. In addition, the inkjet method is suitable for forming the complex pattern shown in FIG. According to the inkjet method, a complicated shape calculated by a computer or the like can be directly printed, and the degree of freedom in shape is high. It is also easy to control the glossiness (Gs 60 °) by partially changing the density, shape, etc. of the fine irregularities 5. These can be performed on a computer screen, and can be designed very easily and have high flexibility with respect to desired design conditions, compared to conventional methods such as blasting and thermal transfer.
Although not shown in the drawings, a transfer method using a casting method or an extrusion molding method using a mold has extremely high transferability and is suitable for forming a fine structure. Therefore, a construction method suitable for the shape may be selected depending on the complexity and fineness of the shape accompanying the adjustment of the glossiness (Gs 60 °).

[Embodiment 2]
FIG. 5 is a configuration diagram of a rear projection type liquid crystal projector according to the second embodiment of the present invention. The rear projection type liquid crystal projector 300 is characterized in that a light transmissive sheet 8 having fine irregularities 7a and 7b formed on both sides is provided between the mirror 1 and the Fresnel lens sheet 2. The fine irregularities 7a and 7b are the same as those described in the first embodiment and are formed in the same manner. The projection light L from the projector device is reflected by the mirror 1 and enters the light transmissive sheet 8. Fine irregularities 7a are formed on the incident surface 8a of the light transmissive sheet 8, and light other than the regular projection light Lc, which becomes image light, is scattered by the fine irregularities 7a. Therefore, the scattered light is vector-decomposed and the intensity is weakened, and does not reach the mirror 1 and does not become retroreflected light. Similarly, even if light other than the regular projection light Lc is reflected by the incident surface 2a of the Fresnel lens sheet 2 and becomes reflected light, it is scattered by the fine irregularities 7b on the exit surface 8b (observation side) of the light-transmitting sheet 8. To do. The scattered light Lr is vector-decomposed and its intensity is weakened, and does not become retroreflected light. The regular projection light Lc as image light is transmitted through the Fresnel lens sheet 2 and projected through the lenticular lens sheet 3.

  As described above, by arranging the light transmissive sheet 8 between the mirror 1 and the Fresnel lens sheet 2, light other than the regular projection light Lc serving as image light is subjected to a scattering effect, and the intensity is weakened. No retroreflected light is generated. As a result, no other light overlaps the image light, and no ghost image is generated. In this configuration, the light transmissive sheet 8 is separate from the optically designed device-specific Fresnel lens sheet 2 and has a single function, so that the user can use the light transmissive sheet 8 as a conventional rear projection projector. It can be added. For example, when watching a conventional rear projection type liquid crystal projector, if a ghost image due to retroreflected light seems to be anxious, a light transmissive sheet 8 on which predetermined fine irregularities 7a and 7b are formed is installed and the ghost image is displayed. Can be prevented.

[Embodiment 3]
FIG. 6 is a block diagram showing a fine unevenness forming apparatus according to Embodiment 3 of the present invention. FIG. 7 is a block diagram of the fine unevenness forming apparatus shown in FIG. The fine unevenness forming apparatus 400 includes a CPU 403 having a control unit 401 and a calculation unit 402, a processing device 405 including a memory 404, a hard disk device storing a predetermined program and fine uneven shape, a magneto-optical disk device, and the like. An external storage device 406, an input device 407 and a display device 408, and an ink jet printer 409 that prints the fine irregularities 5 are configured. The ink jet printer 409 includes a control unit 410, a memory 411 that temporarily stores data, a drive unit 412 that moves while controlling the light transmissive sheet S, and a head unit 413 that ejects ink.

  Further, as shown in FIG. 7, the fine unevenness forming apparatus 400 generates a shape storage unit 421 that stores a plurality of types of fine unevenness shapes, a shape selection unit 422 that selects the shape of fine unevenness, and a random pattern. Random number generation unit 423, pattern generation unit 424 that generates a pattern of fine irregularities, and printing unit 425 that performs ink jet printing on the light-transmitting sheet S, each of which has a hardware configuration shown in FIG. Realized by the program.

  FIG. 8 is a flowchart showing the operation of the fine unevenness forming apparatus. First, the shape selection unit 422 selects a desired shape from a plurality of types of fine concavo-convex shapes stored in the shape storage unit 421 (step S1). The shape of the fine unevenness is read from the external storage device 406 and displayed on the display device 408. The user selects a desired shape on the screen, so that a predetermined fine uneven shape is passed to the pattern generation unit 424.

  Subsequently, the random number generation unit 423 generates a non-reproducible random number based on a predetermined mathematical program (step S2). Next, the pattern generation unit 424 randomly arranges the fine concavo-convex shape selected based on the random number on the light transmissive sheet S (step S3). As described above, the random arrangement is optimal for eliminating the interference with the lenticular lens and obtaining a good screen free from moire.

  The generated random pattern can be confirmed on the display device 408. The fine uneven pattern is transferred to the printing unit and temporarily stored in the memory 411. The drive unit 412 controls and moves the light transmissive sheet S and the head unit 413 in accordance with a command from the control unit 410, and ejects ink (step S4). The head unit 413 can employ a piezo method or a thermal method. Thereby, the fine uneven | corrugated shape of a predetermined pattern is formed on the light-transmitting sheet S. As the ink used here, a pigment-based ink such as a clear lacquer, a mold material such as a photo-curing resin, or the like can be used.

  According to the fine unevenness forming apparatus 400, since the random pattern is formed by the operation on the computer, the fine unevenness can be easily arranged, and the calibration work can be freely performed. In addition, since the formation of the fine unevenness is performed by ink jetting, even the fine unevenness having a complicated shape can be easily formed, and the fine unevenness can be formed with high accuracy. Furthermore, even if it is a material different from the light-transmitting sheet to be formed by inkjet, it can be formed on the upper surface thereof.

  In the above process, a plurality of fine uneven shapes can be selected, and a pattern may be generated by randomly arranging the plurality of fine uneven shapes. The fine uneven shape printed based on the pattern is, for example, a pattern as shown in FIG. Further, the detailed dimensions such as the height difference and the maximum diameter of the fine uneven shape can be reflected in the pattern by inputting from the input device 407 in the shape selection unit 422. The printing unit 425 prints and forms a fine uneven shape of a random pattern based on the input conditions such as height difference and maximum diameter.

  6 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed to perform the above-described processing. Also good. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a recording medium such as a portable medium such as a flexible magnetic disk, a magneto-optical disk, a ROM, a CD-ROM, or a hard disk built in a computer system.

  Furthermore, a “computer-readable recording medium” refers to a program that is dynamically executed for a short time, such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. What is held, and what holds a program for a certain period of time, such as volatile memory inside a computer system serving as a server or client in that case, are included. The program may be for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in the computer system.

1 is a configuration diagram illustrating a rear projection type liquid crystal projector according to a first embodiment of the present invention. FIG. It is explanatory drawing which shows the detail of a fine unevenness | corrugation. It is explanatory drawing which shows another example of a fine unevenness | corrugation. It is explanatory drawing which shows another example of a fine unevenness | corrugation. It is a block diagram of the rear projection type liquid crystal projector which concerns on Embodiment 3 of this invention. It is a block diagram which shows the fine unevenness | corrugation formation apparatus which concerns on Embodiment 3 of this invention. It is a block diagram of the fine grooving | roughness formation apparatus shown in FIG. It is a flowchart which shows operation | movement of a fine unevenness | corrugation formation apparatus. It is explanatory drawing of the generation | occurrence | production principle of the ghost resulting from retroreflection.

Explanation of symbols

100 Rear-projection type liquid crystal projector 1 Mirror 2 Fresnel lens sheet 3 Lenticular lens sheet 4 Transmission type screen 5 Fine unevenness

Claims (7)

Rear projection type in which hemispherical or substantially conical fine irregularities are randomly formed on the incident surface on which image projection light is incident, and the height difference of the fine irregularities is 5 μm to 15 μm and the maximum diameter is 35 μm to 65 μm. A light transmissive sheet used in a projector,
A light-transmitting sheet used for a rear projection projector, wherein a random pattern of the fine unevenness is generated, and the fine unevenness is formed by an ink jet method according to the pattern.   A rear projection projector comprising the light transmissive sheet according to claim 1, wherein an emission surface of the light transmissive sheet is a Fresnel lens of a transmissive screen.   The light transmissive sheet according to claim 1, wherein the light transmissive sheet is disposed between a Fresnel lens sheet and a mirror constituting a transmissive screen, and an incident surface of the light transmissive sheet; A rear projection projector, wherein the fine irregularities are formed on the exit surface. A pattern generating means for generating a fine uneven pattern for randomly arranging fine unevenness on a light-transmitting sheet to be printed;
According to the generated pattern, fine uneven pattern printing means for forming fine unevenness on the light-transmitting sheet by inkjet,
With
Rear projection type in which hemispherical or substantially conical fine irregularities are randomly formed on the incident surface on which image projection light is incident, and the height difference of the fine irregularities is 5 μm to 15 μm and the maximum diameter is 35 μm to 65 μm. A light-transmitting sheet manufacturing apparatus, which manufactures a light-transmitting sheet used for a projector.   5. The light transmissive sheet manufacturing apparatus according to claim 4, further comprising fine concavo-convex shape selecting means for selecting a shape of fine concavo-convex formed on the light transmissive sheet from a plurality of samples. Computer
A pattern generating means for generating a fine uneven pattern for randomly arranging fine unevenness on a light-transmitting sheet to be printed;
According to the generated pattern, fine uneven pattern printing means for forming fine unevenness on the light-transmitting sheet by inkjet,
To function,
A rear projection type in which hemispherical or substantially conical fine irregularities are randomly formed on an incident surface on which image projection light is incident, and the height difference of these fine irregularities is 5 μm to 15 μm and the maximum diameter is 35 μm to 65 μm. A program for manufacturing a light transmissive sheet used in a projector. Computer
A pattern generating means for generating a fine uneven pattern for randomly arranging fine unevenness on a light-transmitting sheet to be printed;
According to the generated pattern, fine uneven pattern printing means for forming fine unevenness on the light-transmitting sheet by inkjet,
To function,
A rear projection type in which hemispherical or substantially conical fine irregularities are randomly formed on an incident surface on which image projection light is incident, and the height difference of these fine irregularities is 5 μm to 15 μm and the maximum diameter is 35 μm to 65 μm. A computer-readable recording medium on which a program for manufacturing a light transmissive sheet used in a projector is recorded.

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